annotate docs/tutorial/LangImpl2.rst @ 15:66597e792247

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author Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
date Tue, 17 Sep 2013 21:32:34 +0900
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1 ===========================================
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2 Kaleidoscope: Implementing a Parser and AST
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3 ===========================================
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5 .. contents::
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6 :local:
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8 Chapter 2 Introduction
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9 ======================
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11 Welcome to Chapter 2 of the "`Implementing a language with
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12 LLVM <index.html>`_" tutorial. This chapter shows you how to use the
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13 lexer, built in `Chapter 1 <LangImpl1.html>`_, to build a full
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14 `parser <http://en.wikipedia.org/wiki/Parsing>`_ for our Kaleidoscope
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15 language. Once we have a parser, we'll define and build an `Abstract
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16 Syntax Tree <http://en.wikipedia.org/wiki/Abstract_syntax_tree>`_ (AST).
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18 The parser we will build uses a combination of `Recursive Descent
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19 Parsing <http://en.wikipedia.org/wiki/Recursive_descent_parser>`_ and
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20 `Operator-Precedence
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21 Parsing <http://en.wikipedia.org/wiki/Operator-precedence_parser>`_ to
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22 parse the Kaleidoscope language (the latter for binary expressions and
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23 the former for everything else). Before we get to parsing though, lets
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24 talk about the output of the parser: the Abstract Syntax Tree.
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25
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26 The Abstract Syntax Tree (AST)
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27 ==============================
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29 The AST for a program captures its behavior in such a way that it is
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30 easy for later stages of the compiler (e.g. code generation) to
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31 interpret. We basically want one object for each construct in the
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32 language, and the AST should closely model the language. In
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33 Kaleidoscope, we have expressions, a prototype, and a function object.
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34 We'll start with expressions first:
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35
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36 .. code-block:: c++
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38 /// ExprAST - Base class for all expression nodes.
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39 class ExprAST {
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40 public:
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41 virtual ~ExprAST() {}
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42 };
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44 /// NumberExprAST - Expression class for numeric literals like "1.0".
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45 class NumberExprAST : public ExprAST {
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46 double Val;
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47 public:
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48 NumberExprAST(double val) : Val(val) {}
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49 };
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50
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51 The code above shows the definition of the base ExprAST class and one
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52 subclass which we use for numeric literals. The important thing to note
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53 about this code is that the NumberExprAST class captures the numeric
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54 value of the literal as an instance variable. This allows later phases
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55 of the compiler to know what the stored numeric value is.
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56
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57 Right now we only create the AST, so there are no useful accessor
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58 methods on them. It would be very easy to add a virtual method to pretty
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59 print the code, for example. Here are the other expression AST node
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60 definitions that we'll use in the basic form of the Kaleidoscope
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61 language:
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62
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63 .. code-block:: c++
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64
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65 /// VariableExprAST - Expression class for referencing a variable, like "a".
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66 class VariableExprAST : public ExprAST {
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67 std::string Name;
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68 public:
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69 VariableExprAST(const std::string &name) : Name(name) {}
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70 };
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71
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72 /// BinaryExprAST - Expression class for a binary operator.
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73 class BinaryExprAST : public ExprAST {
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74 char Op;
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75 ExprAST *LHS, *RHS;
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76 public:
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77 BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
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78 : Op(op), LHS(lhs), RHS(rhs) {}
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79 };
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80
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81 /// CallExprAST - Expression class for function calls.
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82 class CallExprAST : public ExprAST {
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83 std::string Callee;
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84 std::vector<ExprAST*> Args;
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85 public:
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86 CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
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87 : Callee(callee), Args(args) {}
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88 };
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89
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90 This is all (intentionally) rather straight-forward: variables capture
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91 the variable name, binary operators capture their opcode (e.g. '+'), and
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92 calls capture a function name as well as a list of any argument
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93 expressions. One thing that is nice about our AST is that it captures
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94 the language features without talking about the syntax of the language.
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95 Note that there is no discussion about precedence of binary operators,
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96 lexical structure, etc.
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97
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98 For our basic language, these are all of the expression nodes we'll
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99 define. Because it doesn't have conditional control flow, it isn't
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100 Turing-complete; we'll fix that in a later installment. The two things
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101 we need next are a way to talk about the interface to a function, and a
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102 way to talk about functions themselves:
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103
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104 .. code-block:: c++
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105
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106 /// PrototypeAST - This class represents the "prototype" for a function,
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107 /// which captures its name, and its argument names (thus implicitly the number
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108 /// of arguments the function takes).
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109 class PrototypeAST {
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110 std::string Name;
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111 std::vector<std::string> Args;
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112 public:
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113 PrototypeAST(const std::string &name, const std::vector<std::string> &args)
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114 : Name(name), Args(args) {}
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115 };
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116
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117 /// FunctionAST - This class represents a function definition itself.
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118 class FunctionAST {
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119 PrototypeAST *Proto;
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120 ExprAST *Body;
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121 public:
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122 FunctionAST(PrototypeAST *proto, ExprAST *body)
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123 : Proto(proto), Body(body) {}
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124 };
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125
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126 In Kaleidoscope, functions are typed with just a count of their
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127 arguments. Since all values are double precision floating point, the
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128 type of each argument doesn't need to be stored anywhere. In a more
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129 aggressive and realistic language, the "ExprAST" class would probably
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130 have a type field.
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131
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132 With this scaffolding, we can now talk about parsing expressions and
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133 function bodies in Kaleidoscope.
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134
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135 Parser Basics
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136 =============
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137
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138 Now that we have an AST to build, we need to define the parser code to
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139 build it. The idea here is that we want to parse something like "x+y"
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140 (which is returned as three tokens by the lexer) into an AST that could
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141 be generated with calls like this:
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142
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143 .. code-block:: c++
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144
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145 ExprAST *X = new VariableExprAST("x");
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146 ExprAST *Y = new VariableExprAST("y");
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147 ExprAST *Result = new BinaryExprAST('+', X, Y);
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148
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149 In order to do this, we'll start by defining some basic helper routines:
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150
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151 .. code-block:: c++
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152
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153 /// CurTok/getNextToken - Provide a simple token buffer. CurTok is the current
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154 /// token the parser is looking at. getNextToken reads another token from the
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155 /// lexer and updates CurTok with its results.
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156 static int CurTok;
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157 static int getNextToken() {
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158 return CurTok = gettok();
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159 }
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160
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161 This implements a simple token buffer around the lexer. This allows us
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162 to look one token ahead at what the lexer is returning. Every function
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163 in our parser will assume that CurTok is the current token that needs to
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164 be parsed.
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165
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166 .. code-block:: c++
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167
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168
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169 /// Error* - These are little helper functions for error handling.
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170 ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
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171 PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
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172 FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
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173
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174 The ``Error`` routines are simple helper routines that our parser will
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175 use to handle errors. The error recovery in our parser will not be the
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176 best and is not particular user-friendly, but it will be enough for our
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177 tutorial. These routines make it easier to handle errors in routines
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178 that have various return types: they always return null.
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179
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180 With these basic helper functions, we can implement the first piece of
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181 our grammar: numeric literals.
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182
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183 Basic Expression Parsing
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184 ========================
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185
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186 We start with numeric literals, because they are the simplest to
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187 process. For each production in our grammar, we'll define a function
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188 which parses that production. For numeric literals, we have:
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189
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190 .. code-block:: c++
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191
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192 /// numberexpr ::= number
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193 static ExprAST *ParseNumberExpr() {
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194 ExprAST *Result = new NumberExprAST(NumVal);
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195 getNextToken(); // consume the number
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196 return Result;
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197 }
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198
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199 This routine is very simple: it expects to be called when the current
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200 token is a ``tok_number`` token. It takes the current number value,
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201 creates a ``NumberExprAST`` node, advances the lexer to the next token,
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202 and finally returns.
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203
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204 There are some interesting aspects to this. The most important one is
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205 that this routine eats all of the tokens that correspond to the
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206 production and returns the lexer buffer with the next token (which is
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207 not part of the grammar production) ready to go. This is a fairly
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208 standard way to go for recursive descent parsers. For a better example,
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209 the parenthesis operator is defined like this:
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210
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211 .. code-block:: c++
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212
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213 /// parenexpr ::= '(' expression ')'
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214 static ExprAST *ParseParenExpr() {
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215 getNextToken(); // eat (.
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216 ExprAST *V = ParseExpression();
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217 if (!V) return 0;
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218
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219 if (CurTok != ')')
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220 return Error("expected ')'");
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221 getNextToken(); // eat ).
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222 return V;
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223 }
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224
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225 This function illustrates a number of interesting things about the
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226 parser:
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227
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228 1) It shows how we use the Error routines. When called, this function
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229 expects that the current token is a '(' token, but after parsing the
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230 subexpression, it is possible that there is no ')' waiting. For example,
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231 if the user types in "(4 x" instead of "(4)", the parser should emit an
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232 error. Because errors can occur, the parser needs a way to indicate that
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233 they happened: in our parser, we return null on an error.
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234
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235 2) Another interesting aspect of this function is that it uses recursion
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236 by calling ``ParseExpression`` (we will soon see that
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237 ``ParseExpression`` can call ``ParseParenExpr``). This is powerful
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238 because it allows us to handle recursive grammars, and keeps each
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239 production very simple. Note that parentheses do not cause construction
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240 of AST nodes themselves. While we could do it this way, the most
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241 important role of parentheses are to guide the parser and provide
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242 grouping. Once the parser constructs the AST, parentheses are not
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243 needed.
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244
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245 The next simple production is for handling variable references and
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246 function calls:
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247
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248 .. code-block:: c++
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249
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250 /// identifierexpr
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251 /// ::= identifier
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252 /// ::= identifier '(' expression* ')'
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253 static ExprAST *ParseIdentifierExpr() {
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254 std::string IdName = IdentifierStr;
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255
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256 getNextToken(); // eat identifier.
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257
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258 if (CurTok != '(') // Simple variable ref.
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259 return new VariableExprAST(IdName);
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260
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261 // Call.
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262 getNextToken(); // eat (
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263 std::vector<ExprAST*> Args;
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264 if (CurTok != ')') {
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265 while (1) {
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266 ExprAST *Arg = ParseExpression();
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267 if (!Arg) return 0;
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268 Args.push_back(Arg);
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269
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270 if (CurTok == ')') break;
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271
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272 if (CurTok != ',')
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273 return Error("Expected ')' or ',' in argument list");
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274 getNextToken();
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275 }
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276 }
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277
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278 // Eat the ')'.
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279 getNextToken();
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280
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281 return new CallExprAST(IdName, Args);
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282 }
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283
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284 This routine follows the same style as the other routines. (It expects
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285 to be called if the current token is a ``tok_identifier`` token). It
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286 also has recursion and error handling. One interesting aspect of this is
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287 that it uses *look-ahead* to determine if the current identifier is a
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288 stand alone variable reference or if it is a function call expression.
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289 It handles this by checking to see if the token after the identifier is
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290 a '(' token, constructing either a ``VariableExprAST`` or
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291 ``CallExprAST`` node as appropriate.
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292
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293 Now that we have all of our simple expression-parsing logic in place, we
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294 can define a helper function to wrap it together into one entry point.
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295 We call this class of expressions "primary" expressions, for reasons
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296 that will become more clear `later in the
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297 tutorial <LangImpl6.html#unary>`_. In order to parse an arbitrary
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298 primary expression, we need to determine what sort of expression it is:
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299
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300 .. code-block:: c++
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301
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302 /// primary
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303 /// ::= identifierexpr
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304 /// ::= numberexpr
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305 /// ::= parenexpr
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306 static ExprAST *ParsePrimary() {
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307 switch (CurTok) {
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308 default: return Error("unknown token when expecting an expression");
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309 case tok_identifier: return ParseIdentifierExpr();
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310 case tok_number: return ParseNumberExpr();
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311 case '(': return ParseParenExpr();
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312 }
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313 }
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314
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315 Now that you see the definition of this function, it is more obvious why
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316 we can assume the state of CurTok in the various functions. This uses
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317 look-ahead to determine which sort of expression is being inspected, and
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318 then parses it with a function call.
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319
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320 Now that basic expressions are handled, we need to handle binary
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321 expressions. They are a bit more complex.
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322
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323 Binary Expression Parsing
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324 =========================
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325
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326 Binary expressions are significantly harder to parse because they are
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327 often ambiguous. For example, when given the string "x+y\*z", the parser
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328 can choose to parse it as either "(x+y)\*z" or "x+(y\*z)". With common
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329 definitions from mathematics, we expect the later parse, because "\*"
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330 (multiplication) has higher *precedence* than "+" (addition).
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331
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332 There are many ways to handle this, but an elegant and efficient way is
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333 to use `Operator-Precedence
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334 Parsing <http://en.wikipedia.org/wiki/Operator-precedence_parser>`_.
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335 This parsing technique uses the precedence of binary operators to guide
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336 recursion. To start with, we need a table of precedences:
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337
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338 .. code-block:: c++
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339
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340 /// BinopPrecedence - This holds the precedence for each binary operator that is
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341 /// defined.
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342 static std::map<char, int> BinopPrecedence;
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343
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344 /// GetTokPrecedence - Get the precedence of the pending binary operator token.
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345 static int GetTokPrecedence() {
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346 if (!isascii(CurTok))
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347 return -1;
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348
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349 // Make sure it's a declared binop.
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350 int TokPrec = BinopPrecedence[CurTok];
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351 if (TokPrec <= 0) return -1;
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352 return TokPrec;
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353 }
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354
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355 int main() {
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356 // Install standard binary operators.
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357 // 1 is lowest precedence.
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358 BinopPrecedence['<'] = 10;
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359 BinopPrecedence['+'] = 20;
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360 BinopPrecedence['-'] = 20;
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361 BinopPrecedence['*'] = 40; // highest.
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parents:
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362 ...
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
363 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
364
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
365 For the basic form of Kaleidoscope, we will only support 4 binary
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
366 operators (this can obviously be extended by you, our brave and intrepid
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
367 reader). The ``GetTokPrecedence`` function returns the precedence for
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
368 the current token, or -1 if the token is not a binary operator. Having a
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
369 map makes it easy to add new operators and makes it clear that the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
370 algorithm doesn't depend on the specific operators involved, but it
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
371 would be easy enough to eliminate the map and do the comparisons in the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
372 ``GetTokPrecedence`` function. (Or just use a fixed-size array).
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
373
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
374 With the helper above defined, we can now start parsing binary
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
375 expressions. The basic idea of operator precedence parsing is to break
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
376 down an expression with potentially ambiguous binary operators into
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
377 pieces. Consider ,for example, the expression "a+b+(c+d)\*e\*f+g".
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
378 Operator precedence parsing considers this as a stream of primary
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
379 expressions separated by binary operators. As such, it will first parse
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
380 the leading primary expression "a", then it will see the pairs [+, b]
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
381 [+, (c+d)] [\*, e] [\*, f] and [+, g]. Note that because parentheses are
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
382 primary expressions, the binary expression parser doesn't need to worry
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
383 about nested subexpressions like (c+d) at all.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
384
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
385 To start, an expression is a primary expression potentially followed by
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
386 a sequence of [binop,primaryexpr] pairs:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
387
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
388 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
389
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
390 /// expression
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
391 /// ::= primary binoprhs
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
392 ///
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
393 static ExprAST *ParseExpression() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
394 ExprAST *LHS = ParsePrimary();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
395 if (!LHS) return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
396
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
397 return ParseBinOpRHS(0, LHS);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
398 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
399
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
400 ``ParseBinOpRHS`` is the function that parses the sequence of pairs for
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
401 us. It takes a precedence and a pointer to an expression for the part
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
402 that has been parsed so far. Note that "x" is a perfectly valid
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
403 expression: As such, "binoprhs" is allowed to be empty, in which case it
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
404 returns the expression that is passed into it. In our example above, the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
405 code passes the expression for "a" into ``ParseBinOpRHS`` and the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
406 current token is "+".
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
407
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
408 The precedence value passed into ``ParseBinOpRHS`` indicates the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
409 *minimal operator precedence* that the function is allowed to eat. For
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
410 example, if the current pair stream is [+, x] and ``ParseBinOpRHS`` is
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
411 passed in a precedence of 40, it will not consume any tokens (because
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
412 the precedence of '+' is only 20). With this in mind, ``ParseBinOpRHS``
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
413 starts with:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
414
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
415 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
416
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
417 /// binoprhs
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
418 /// ::= ('+' primary)*
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
419 static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
420 // If this is a binop, find its precedence.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
421 while (1) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
422 int TokPrec = GetTokPrecedence();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
423
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
424 // If this is a binop that binds at least as tightly as the current binop,
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
425 // consume it, otherwise we are done.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
426 if (TokPrec < ExprPrec)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
427 return LHS;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
428
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
429 This code gets the precedence of the current token and checks to see if
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
430 if is too low. Because we defined invalid tokens to have a precedence of
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
431 -1, this check implicitly knows that the pair-stream ends when the token
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
432 stream runs out of binary operators. If this check succeeds, we know
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
433 that the token is a binary operator and that it will be included in this
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
434 expression:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
435
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
436 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
437
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
438 // Okay, we know this is a binop.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
439 int BinOp = CurTok;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
440 getNextToken(); // eat binop
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
441
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
442 // Parse the primary expression after the binary operator.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
443 ExprAST *RHS = ParsePrimary();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
444 if (!RHS) return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
445
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
446 As such, this code eats (and remembers) the binary operator and then
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
447 parses the primary expression that follows. This builds up the whole
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
448 pair, the first of which is [+, b] for the running example.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
449
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
450 Now that we parsed the left-hand side of an expression and one pair of
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
451 the RHS sequence, we have to decide which way the expression associates.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
452 In particular, we could have "(a+b) binop unparsed" or "a + (b binop
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
453 unparsed)". To determine this, we look ahead at "binop" to determine its
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
454 precedence and compare it to BinOp's precedence (which is '+' in this
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
455 case):
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
456
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
457 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
458
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
459 // If BinOp binds less tightly with RHS than the operator after RHS, let
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
460 // the pending operator take RHS as its LHS.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
461 int NextPrec = GetTokPrecedence();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
462 if (TokPrec < NextPrec) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
463
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
464 If the precedence of the binop to the right of "RHS" is lower or equal
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
465 to the precedence of our current operator, then we know that the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
466 parentheses associate as "(a+b) binop ...". In our example, the current
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
467 operator is "+" and the next operator is "+", we know that they have the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
468 same precedence. In this case we'll create the AST node for "a+b", and
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
469 then continue parsing:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
470
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
471 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
472
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
473 ... if body omitted ...
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
474 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
475
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
476 // Merge LHS/RHS.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
477 LHS = new BinaryExprAST(BinOp, LHS, RHS);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
478 } // loop around to the top of the while loop.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
479 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
480
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
481 In our example above, this will turn "a+b+" into "(a+b)" and execute the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
482 next iteration of the loop, with "+" as the current token. The code
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
483 above will eat, remember, and parse "(c+d)" as the primary expression,
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
484 which makes the current pair equal to [+, (c+d)]. It will then evaluate
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
485 the 'if' conditional above with "\*" as the binop to the right of the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
486 primary. In this case, the precedence of "\*" is higher than the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
487 precedence of "+" so the if condition will be entered.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
488
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
489 The critical question left here is "how can the if condition parse the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
490 right hand side in full"? In particular, to build the AST correctly for
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
491 our example, it needs to get all of "(c+d)\*e\*f" as the RHS expression
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
492 variable. The code to do this is surprisingly simple (code from the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
493 above two blocks duplicated for context):
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
494
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
495 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
496
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
497 // If BinOp binds less tightly with RHS than the operator after RHS, let
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
498 // the pending operator take RHS as its LHS.
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
499 int NextPrec = GetTokPrecedence();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
500 if (TokPrec < NextPrec) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
501 RHS = ParseBinOpRHS(TokPrec+1, RHS);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
502 if (RHS == 0) return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
503 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
504 // Merge LHS/RHS.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
505 LHS = new BinaryExprAST(BinOp, LHS, RHS);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
506 } // loop around to the top of the while loop.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
507 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
508
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
509 At this point, we know that the binary operator to the RHS of our
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
510 primary has higher precedence than the binop we are currently parsing.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
511 As such, we know that any sequence of pairs whose operators are all
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
512 higher precedence than "+" should be parsed together and returned as
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
513 "RHS". To do this, we recursively invoke the ``ParseBinOpRHS`` function
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
514 specifying "TokPrec+1" as the minimum precedence required for it to
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
515 continue. In our example above, this will cause it to return the AST
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
516 node for "(c+d)\*e\*f" as RHS, which is then set as the RHS of the '+'
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
517 expression.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
518
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
519 Finally, on the next iteration of the while loop, the "+g" piece is
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
520 parsed and added to the AST. With this little bit of code (14
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
521 non-trivial lines), we correctly handle fully general binary expression
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
522 parsing in a very elegant way. This was a whirlwind tour of this code,
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
523 and it is somewhat subtle. I recommend running through it with a few
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
524 tough examples to see how it works.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
525
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
526 This wraps up handling of expressions. At this point, we can point the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
527 parser at an arbitrary token stream and build an expression from it,
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
528 stopping at the first token that is not part of the expression. Next up
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
529 we need to handle function definitions, etc.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
530
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
531 Parsing the Rest
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
532 ================
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
533
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
534 The next thing missing is handling of function prototypes. In
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
535 Kaleidoscope, these are used both for 'extern' function declarations as
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
536 well as function body definitions. The code to do this is
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
537 straight-forward and not very interesting (once you've survived
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
538 expressions):
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
539
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
540 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
541
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
542 /// prototype
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
543 /// ::= id '(' id* ')'
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
544 static PrototypeAST *ParsePrototype() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
545 if (CurTok != tok_identifier)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
546 return ErrorP("Expected function name in prototype");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
547
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
548 std::string FnName = IdentifierStr;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
549 getNextToken();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
550
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
551 if (CurTok != '(')
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
552 return ErrorP("Expected '(' in prototype");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
553
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
554 // Read the list of argument names.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
555 std::vector<std::string> ArgNames;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
556 while (getNextToken() == tok_identifier)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
557 ArgNames.push_back(IdentifierStr);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
558 if (CurTok != ')')
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
559 return ErrorP("Expected ')' in prototype");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
560
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
561 // success.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
562 getNextToken(); // eat ')'.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
563
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
564 return new PrototypeAST(FnName, ArgNames);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
565 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
566
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
567 Given this, a function definition is very simple, just a prototype plus
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
568 an expression to implement the body:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
569
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
570 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
571
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
572 /// definition ::= 'def' prototype expression
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
573 static FunctionAST *ParseDefinition() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
574 getNextToken(); // eat def.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
575 PrototypeAST *Proto = ParsePrototype();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
576 if (Proto == 0) return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
577
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
578 if (ExprAST *E = ParseExpression())
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
579 return new FunctionAST(Proto, E);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
580 return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
581 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
582
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
583 In addition, we support 'extern' to declare functions like 'sin' and
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
584 'cos' as well as to support forward declaration of user functions. These
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
585 'extern's are just prototypes with no body:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
586
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
587 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
588
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
589 /// external ::= 'extern' prototype
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
590 static PrototypeAST *ParseExtern() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
591 getNextToken(); // eat extern.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
592 return ParsePrototype();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
593 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
594
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
595 Finally, we'll also let the user type in arbitrary top-level expressions
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
596 and evaluate them on the fly. We will handle this by defining anonymous
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
597 nullary (zero argument) functions for them:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
598
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
599 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
600
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
601 /// toplevelexpr ::= expression
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
602 static FunctionAST *ParseTopLevelExpr() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
603 if (ExprAST *E = ParseExpression()) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
604 // Make an anonymous proto.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
605 PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
606 return new FunctionAST(Proto, E);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
607 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
608 return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
609 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
610
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
611 Now that we have all the pieces, let's build a little driver that will
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
612 let us actually *execute* this code we've built!
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
613
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
614 The Driver
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
615 ==========
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
616
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
617 The driver for this simply invokes all of the parsing pieces with a
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
618 top-level dispatch loop. There isn't much interesting here, so I'll just
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
619 include the top-level loop. See `below <#code>`_ for full code in the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
620 "Top-Level Parsing" section.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
621
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
622 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
623
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
624 /// top ::= definition | external | expression | ';'
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
625 static void MainLoop() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
626 while (1) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
627 fprintf(stderr, "ready> ");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
628 switch (CurTok) {
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
629 case tok_eof: return;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
630 case ';': getNextToken(); break; // ignore top-level semicolons.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
631 case tok_def: HandleDefinition(); break;
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
632 case tok_extern: HandleExtern(); break;
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
633 default: HandleTopLevelExpression(); break;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
634 }
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
635 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
636 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
637
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
638 The most interesting part of this is that we ignore top-level
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
639 semicolons. Why is this, you ask? The basic reason is that if you type
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
640 "4 + 5" at the command line, the parser doesn't know whether that is the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
641 end of what you will type or not. For example, on the next line you
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
642 could type "def foo..." in which case 4+5 is the end of a top-level
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
643 expression. Alternatively you could type "\* 6", which would continue
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
644 the expression. Having top-level semicolons allows you to type "4+5;",
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
645 and the parser will know you are done.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
646
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
647 Conclusions
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
648 ===========
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
649
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
650 With just under 400 lines of commented code (240 lines of non-comment,
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
651 non-blank code), we fully defined our minimal language, including a
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
652 lexer, parser, and AST builder. With this done, the executable will
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
653 validate Kaleidoscope code and tell us if it is grammatically invalid.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
654 For example, here is a sample interaction:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
655
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
656 .. code-block:: bash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
657
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
658 $ ./a.out
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
659 ready> def foo(x y) x+foo(y, 4.0);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
660 Parsed a function definition.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
661 ready> def foo(x y) x+y y;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
662 Parsed a function definition.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
663 Parsed a top-level expr
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
664 ready> def foo(x y) x+y );
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
665 Parsed a function definition.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
666 Error: unknown token when expecting an expression
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
667 ready> extern sin(a);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
668 ready> Parsed an extern
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
669 ready> ^D
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
670 $
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
671
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
672 There is a lot of room for extension here. You can define new AST nodes,
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
673 extend the language in many ways, etc. In the `next
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
674 installment <LangImpl3.html>`_, we will describe how to generate LLVM
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
675 Intermediate Representation (IR) from the AST.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
676
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
677 Full Code Listing
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
678 =================
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
679
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
680 Here is the complete code listing for this and the previous chapter.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
681 Note that it is fully self-contained: you don't need LLVM or any
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
682 external libraries at all for this. (Besides the C and C++ standard
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
683 libraries, of course.) To build this, just compile with:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
684
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
685 .. code-block:: bash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
686
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
687 # Compile
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
688 clang++ -g -O3 toy.cpp
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
689 # Run
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
690 ./a.out
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
691
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
692 Here is the code:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
693
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
694 .. code-block:: c++
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
695
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
696 #include <cstdio>
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
697 #include <cstdlib>
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
698 #include <string>
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
699 #include <map>
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
700 #include <vector>
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
701
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Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
702 //===----------------------------------------------------------------------===//
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
703 // Lexer
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
704 //===----------------------------------------------------------------------===//
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
705
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
706 // The lexer returns tokens [0-255] if it is an unknown character, otherwise one
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
707 // of these for known things.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
708 enum Token {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
709 tok_eof = -1,
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
710
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
711 // commands
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
712 tok_def = -2, tok_extern = -3,
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
713
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
714 // primary
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
715 tok_identifier = -4, tok_number = -5
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
716 };
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
717
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
718 static std::string IdentifierStr; // Filled in if tok_identifier
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
719 static double NumVal; // Filled in if tok_number
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
720
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
721 /// gettok - Return the next token from standard input.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
722 static int gettok() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
723 static int LastChar = ' ';
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
724
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
725 // Skip any whitespace.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
726 while (isspace(LastChar))
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
727 LastChar = getchar();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
728
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
729 if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
730 IdentifierStr = LastChar;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
731 while (isalnum((LastChar = getchar())))
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
732 IdentifierStr += LastChar;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
733
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
734 if (IdentifierStr == "def") return tok_def;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
735 if (IdentifierStr == "extern") return tok_extern;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
736 return tok_identifier;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
737 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
738
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
739 if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
740 std::string NumStr;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
741 do {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
742 NumStr += LastChar;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
743 LastChar = getchar();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
744 } while (isdigit(LastChar) || LastChar == '.');
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
745
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
746 NumVal = strtod(NumStr.c_str(), 0);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
747 return tok_number;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
748 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
749
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
750 if (LastChar == '#') {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
751 // Comment until end of line.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
752 do LastChar = getchar();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
753 while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
754
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
755 if (LastChar != EOF)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
756 return gettok();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
757 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
758
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
759 // Check for end of file. Don't eat the EOF.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
760 if (LastChar == EOF)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
761 return tok_eof;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
762
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
763 // Otherwise, just return the character as its ascii value.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
764 int ThisChar = LastChar;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
765 LastChar = getchar();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
766 return ThisChar;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
767 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
768
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
769 //===----------------------------------------------------------------------===//
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
770 // Abstract Syntax Tree (aka Parse Tree)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
771 //===----------------------------------------------------------------------===//
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
772
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
773 /// ExprAST - Base class for all expression nodes.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
774 class ExprAST {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
775 public:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
776 virtual ~ExprAST() {}
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
777 };
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
778
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
779 /// NumberExprAST - Expression class for numeric literals like "1.0".
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
780 class NumberExprAST : public ExprAST {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
781 double Val;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
782 public:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
783 NumberExprAST(double val) : Val(val) {}
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
784 };
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
785
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
786 /// VariableExprAST - Expression class for referencing a variable, like "a".
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
787 class VariableExprAST : public ExprAST {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
788 std::string Name;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
789 public:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
790 VariableExprAST(const std::string &name) : Name(name) {}
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
791 };
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
792
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
793 /// BinaryExprAST - Expression class for a binary operator.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
794 class BinaryExprAST : public ExprAST {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
795 char Op;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
796 ExprAST *LHS, *RHS;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
797 public:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
798 BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
799 : Op(op), LHS(lhs), RHS(rhs) {}
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
800 };
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
801
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
802 /// CallExprAST - Expression class for function calls.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
803 class CallExprAST : public ExprAST {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
804 std::string Callee;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
805 std::vector<ExprAST*> Args;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
806 public:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
807 CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
808 : Callee(callee), Args(args) {}
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
809 };
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
810
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
811 /// PrototypeAST - This class represents the "prototype" for a function,
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
812 /// which captures its name, and its argument names (thus implicitly the number
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
813 /// of arguments the function takes).
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
814 class PrototypeAST {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
815 std::string Name;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
816 std::vector<std::string> Args;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
817 public:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
818 PrototypeAST(const std::string &name, const std::vector<std::string> &args)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
819 : Name(name), Args(args) {}
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
820
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
821 };
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
822
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
823 /// FunctionAST - This class represents a function definition itself.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
824 class FunctionAST {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
825 PrototypeAST *Proto;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
826 ExprAST *Body;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
827 public:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
828 FunctionAST(PrototypeAST *proto, ExprAST *body)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
829 : Proto(proto), Body(body) {}
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
830
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
831 };
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
832
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
833 //===----------------------------------------------------------------------===//
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
834 // Parser
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
835 //===----------------------------------------------------------------------===//
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
836
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
837 /// CurTok/getNextToken - Provide a simple token buffer. CurTok is the current
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
838 /// token the parser is looking at. getNextToken reads another token from the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
839 /// lexer and updates CurTok with its results.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
840 static int CurTok;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
841 static int getNextToken() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
842 return CurTok = gettok();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
843 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
844
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
845 /// BinopPrecedence - This holds the precedence for each binary operator that is
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
846 /// defined.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
847 static std::map<char, int> BinopPrecedence;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
848
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
849 /// GetTokPrecedence - Get the precedence of the pending binary operator token.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
850 static int GetTokPrecedence() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
851 if (!isascii(CurTok))
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
852 return -1;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
853
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
854 // Make sure it's a declared binop.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
855 int TokPrec = BinopPrecedence[CurTok];
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
856 if (TokPrec <= 0) return -1;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
857 return TokPrec;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
858 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
859
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
860 /// Error* - These are little helper functions for error handling.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
861 ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
862 PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
863 FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
864
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
865 static ExprAST *ParseExpression();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
866
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
867 /// identifierexpr
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
868 /// ::= identifier
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
869 /// ::= identifier '(' expression* ')'
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
870 static ExprAST *ParseIdentifierExpr() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
871 std::string IdName = IdentifierStr;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
872
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
873 getNextToken(); // eat identifier.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
874
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
875 if (CurTok != '(') // Simple variable ref.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
876 return new VariableExprAST(IdName);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
877
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
878 // Call.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
879 getNextToken(); // eat (
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
880 std::vector<ExprAST*> Args;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
881 if (CurTok != ')') {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
882 while (1) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
883 ExprAST *Arg = ParseExpression();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
884 if (!Arg) return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
885 Args.push_back(Arg);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
886
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
887 if (CurTok == ')') break;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
888
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
889 if (CurTok != ',')
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
890 return Error("Expected ')' or ',' in argument list");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
891 getNextToken();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
892 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
893 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
894
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
895 // Eat the ')'.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
896 getNextToken();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
897
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
898 return new CallExprAST(IdName, Args);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
899 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
900
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
901 /// numberexpr ::= number
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
902 static ExprAST *ParseNumberExpr() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
903 ExprAST *Result = new NumberExprAST(NumVal);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
904 getNextToken(); // consume the number
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
905 return Result;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
906 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
907
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
908 /// parenexpr ::= '(' expression ')'
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
909 static ExprAST *ParseParenExpr() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
910 getNextToken(); // eat (.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
911 ExprAST *V = ParseExpression();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
912 if (!V) return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
913
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
914 if (CurTok != ')')
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
915 return Error("expected ')'");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
916 getNextToken(); // eat ).
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
917 return V;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
918 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
919
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
920 /// primary
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
921 /// ::= identifierexpr
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
922 /// ::= numberexpr
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
923 /// ::= parenexpr
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
924 static ExprAST *ParsePrimary() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
925 switch (CurTok) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
926 default: return Error("unknown token when expecting an expression");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
927 case tok_identifier: return ParseIdentifierExpr();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
928 case tok_number: return ParseNumberExpr();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
929 case '(': return ParseParenExpr();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
930 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
931 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
932
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
933 /// binoprhs
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
934 /// ::= ('+' primary)*
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
935 static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
936 // If this is a binop, find its precedence.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
937 while (1) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
938 int TokPrec = GetTokPrecedence();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
939
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
940 // If this is a binop that binds at least as tightly as the current binop,
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
941 // consume it, otherwise we are done.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
942 if (TokPrec < ExprPrec)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
943 return LHS;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
944
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
945 // Okay, we know this is a binop.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
946 int BinOp = CurTok;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
947 getNextToken(); // eat binop
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
948
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
949 // Parse the primary expression after the binary operator.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
950 ExprAST *RHS = ParsePrimary();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
951 if (!RHS) return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
952
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
953 // If BinOp binds less tightly with RHS than the operator after RHS, let
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
954 // the pending operator take RHS as its LHS.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
955 int NextPrec = GetTokPrecedence();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
956 if (TokPrec < NextPrec) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
957 RHS = ParseBinOpRHS(TokPrec+1, RHS);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
958 if (RHS == 0) return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
959 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
960
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
961 // Merge LHS/RHS.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
962 LHS = new BinaryExprAST(BinOp, LHS, RHS);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
963 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
964 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
965
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
966 /// expression
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
967 /// ::= primary binoprhs
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
968 ///
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
969 static ExprAST *ParseExpression() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
970 ExprAST *LHS = ParsePrimary();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
971 if (!LHS) return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
972
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
973 return ParseBinOpRHS(0, LHS);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
974 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
975
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
976 /// prototype
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
977 /// ::= id '(' id* ')'
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
978 static PrototypeAST *ParsePrototype() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
979 if (CurTok != tok_identifier)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
980 return ErrorP("Expected function name in prototype");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
981
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
982 std::string FnName = IdentifierStr;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
983 getNextToken();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
984
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
985 if (CurTok != '(')
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
986 return ErrorP("Expected '(' in prototype");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
987
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
988 std::vector<std::string> ArgNames;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
989 while (getNextToken() == tok_identifier)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
990 ArgNames.push_back(IdentifierStr);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
991 if (CurTok != ')')
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
992 return ErrorP("Expected ')' in prototype");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
993
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
994 // success.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
995 getNextToken(); // eat ')'.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
996
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
997 return new PrototypeAST(FnName, ArgNames);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
998 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
999
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1000 /// definition ::= 'def' prototype expression
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1001 static FunctionAST *ParseDefinition() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1002 getNextToken(); // eat def.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1003 PrototypeAST *Proto = ParsePrototype();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1004 if (Proto == 0) return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1005
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1006 if (ExprAST *E = ParseExpression())
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1007 return new FunctionAST(Proto, E);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1008 return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1009 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1010
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1011 /// toplevelexpr ::= expression
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1012 static FunctionAST *ParseTopLevelExpr() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1013 if (ExprAST *E = ParseExpression()) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1014 // Make an anonymous proto.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1015 PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1016 return new FunctionAST(Proto, E);
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1017 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1018 return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1019 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1020
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1021 /// external ::= 'extern' prototype
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1022 static PrototypeAST *ParseExtern() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1023 getNextToken(); // eat extern.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1024 return ParsePrototype();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1025 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1026
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1027 //===----------------------------------------------------------------------===//
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1028 // Top-Level parsing
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1029 //===----------------------------------------------------------------------===//
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1030
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1031 static void HandleDefinition() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1032 if (ParseDefinition()) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1033 fprintf(stderr, "Parsed a function definition.\n");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1034 } else {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1035 // Skip token for error recovery.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1036 getNextToken();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1037 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1038 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1039
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1040 static void HandleExtern() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1041 if (ParseExtern()) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1042 fprintf(stderr, "Parsed an extern\n");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1043 } else {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1044 // Skip token for error recovery.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1045 getNextToken();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1046 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1047 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1048
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1049 static void HandleTopLevelExpression() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1050 // Evaluate a top-level expression into an anonymous function.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1051 if (ParseTopLevelExpr()) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1052 fprintf(stderr, "Parsed a top-level expr\n");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1053 } else {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1054 // Skip token for error recovery.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1055 getNextToken();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1056 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1057 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1058
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1059 /// top ::= definition | external | expression | ';'
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1060 static void MainLoop() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1061 while (1) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1062 fprintf(stderr, "ready> ");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1063 switch (CurTok) {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1064 case tok_eof: return;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1065 case ';': getNextToken(); break; // ignore top-level semicolons.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1066 case tok_def: HandleDefinition(); break;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1067 case tok_extern: HandleExtern(); break;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1068 default: HandleTopLevelExpression(); break;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1069 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1070 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1071 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1072
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1073 //===----------------------------------------------------------------------===//
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1074 // Main driver code.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1075 //===----------------------------------------------------------------------===//
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1076
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1077 int main() {
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1078 // Install standard binary operators.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1079 // 1 is lowest precedence.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1080 BinopPrecedence['<'] = 10;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1081 BinopPrecedence['+'] = 20;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1082 BinopPrecedence['-'] = 20;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1083 BinopPrecedence['*'] = 40; // highest.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1084
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1085 // Prime the first token.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1086 fprintf(stderr, "ready> ");
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1087 getNextToken();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1088
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1089 // Run the main "interpreter loop" now.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1090 MainLoop();
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1091
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1092 return 0;
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1093 }
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1094
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1095 `Next: Implementing Code Generation to LLVM IR <LangImpl3.html>`_
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1096