|
150
|
1 ==================================================================
|
|
|
2 Getting Started with the LLVM System using Microsoft Visual Studio
|
|
|
3 ==================================================================
|
|
|
4
|
|
|
5 .. contents::
|
|
|
6 :local:
|
|
|
7
|
|
|
8
|
|
|
9 Overview
|
|
|
10 ========
|
|
|
11 Welcome to LLVM on Windows! This document only covers LLVM on Windows using
|
|
|
12 Visual Studio, not mingw or cygwin. In order to get started, you first need to
|
|
|
13 know some basic information.
|
|
|
14
|
|
|
15 There are many different projects that compose LLVM. The first piece is the
|
|
|
16 LLVM suite. This contains all of the tools, libraries, and header files needed
|
|
|
17 to use LLVM. It contains an assembler, disassembler, bitcode analyzer and
|
|
|
18 bitcode optimizer. It also contains basic regression tests that can be used to
|
|
|
19 test the LLVM tools and the Clang front end.
|
|
|
20
|
|
|
21 The second piece is the `Clang <http://clang.llvm.org/>`_ front end. This
|
|
|
22 component compiles C, C++, Objective C, and Objective C++ code into LLVM
|
|
|
23 bitcode. Clang typically uses LLVM libraries to optimize the bitcode and emit
|
|
|
24 machine code. LLVM fully supports the COFF object file format, which is
|
|
|
25 compatible with all other existing Windows toolchains.
|
|
|
26
|
|
|
27 The last major part of LLVM, the execution Test Suite, does not run on Windows,
|
|
|
28 and this document does not discuss it.
|
|
|
29
|
|
|
30 Additional information about the LLVM directory structure and tool chain
|
|
|
31 can be found on the main :doc:`GettingStarted` page.
|
|
|
32
|
|
|
33
|
|
|
34 Requirements
|
|
|
35 ============
|
|
|
36 Before you begin to use the LLVM system, review the requirements given
|
|
|
37 below. This may save you some trouble by knowing ahead of time what hardware
|
|
|
38 and software you will need.
|
|
|
39
|
|
|
40 Hardware
|
|
|
41 --------
|
|
|
42 Any system that can adequately run Visual Studio 2017 is fine. The LLVM
|
|
|
43 source tree and object files, libraries and executables will consume
|
|
|
44 approximately 3GB.
|
|
|
45
|
|
|
46 Software
|
|
|
47 --------
|
|
|
48 You will need Visual Studio 2017 or higher, with the latest Update installed.
|
|
|
49
|
|
|
50 You will also need the `CMake <http://www.cmake.org/>`_ build system since it
|
|
|
51 generates the project files you will use to build with.
|
|
|
52
|
|
|
53 If you would like to run the LLVM tests you will need `Python
|
|
|
54 <http://www.python.org/>`_. Version 2.7 and newer are known to work. You will
|
|
|
55 need `GnuWin32 <http://gnuwin32.sourceforge.net/>`_ tools, too.
|
|
|
56
|
|
|
57 Do not install the LLVM directory tree into a path containing spaces (e.g.
|
|
|
58 ``C:\Documents and Settings\...``) as the configure step will fail.
|
|
|
59
|
|
|
60
|
|
|
61 Getting Started
|
|
|
62 ===============
|
|
|
63 Here's the short story for getting up and running quickly with LLVM:
|
|
|
64
|
|
|
65 1. Read the documentation.
|
|
|
66 2. Seriously, read the documentation.
|
|
|
67 3. Remember that you were warned twice about reading the documentation.
|
|
|
68 4. Get the Source Code
|
|
|
69
|
|
|
70 * With the distributed files:
|
|
|
71
|
|
|
72 1. ``cd <where-you-want-llvm-to-live>``
|
|
|
73 2. ``gunzip --stdout llvm-VERSION.tar.gz | tar -xvf -``
|
|
|
74 (*or use WinZip*)
|
|
|
75 3. ``cd llvm``
|
|
|
76
|
|
|
77 * With anonymous Subversion access:
|
|
|
78
|
|
|
79 *Note:* some regression tests require Unix-style line ending (``\n``). To
|
|
|
80 pass all regression tests, please add two lines *enable-auto-props = yes*
|
|
|
81 and *\* = svn:mime-type=application/octet-stream* to
|
|
|
82 ``C:\Users\<username>\AppData\Roaming\Subversion\config``.
|
|
|
83
|
|
|
84 1. ``cd <where-you-want-llvm-to-live>``
|
|
|
85 2. ``svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm``
|
|
|
86 3. ``cd llvm``
|
|
|
87
|
|
|
88 5. Use `CMake <http://www.cmake.org/>`_ to generate up-to-date project files:
|
|
|
89
|
|
|
90 * Once CMake is installed then the simplest way is to just start the
|
|
|
91 CMake GUI, select the directory where you have LLVM extracted to, and
|
|
|
92 the default options should all be fine. One option you may really
|
|
|
93 want to change, regardless of anything else, might be the
|
|
|
94 ``CMAKE_INSTALL_PREFIX`` setting to select a directory to INSTALL to
|
|
|
95 once compiling is complete, although installation is not mandatory for
|
|
|
96 using LLVM. Another important option is ``LLVM_TARGETS_TO_BUILD``,
|
|
|
97 which controls the LLVM target architectures that are included on the
|
|
|
98 build.
|
|
|
99 * If CMake complains that it cannot find the compiler, make sure that
|
|
|
100 you have the Visual Studio C++ Tools installed, not just Visual Studio
|
|
|
101 itself (trying to create a C++ project in Visual Studio will generally
|
|
|
102 download the C++ tools if they haven't already been).
|
|
|
103 * See the :doc:`LLVM CMake guide <CMake>` for detailed information about
|
|
|
104 how to configure the LLVM build.
|
|
|
105 * CMake generates project files for all build types. To select a specific
|
|
|
106 build type, use the Configuration manager from the VS IDE or the
|
|
|
107 ``/property:Configuration`` command line option when using MSBuild.
|
|
|
108 * By default, the Visual Studio project files generated by CMake use the
|
|
|
109 32-bit toolset. If you are developing on a 64-bit version of Windows and
|
|
|
110 want to use the 64-bit toolset, pass the ``-Thost=x64`` flag when
|
|
|
111 generating the Visual Studio solution. This requires CMake 3.8.0 or later.
|
|
|
112
|
|
|
113 6. Start Visual Studio
|
|
|
114
|
|
|
115 * In the directory you created the project files will have an ``llvm.sln``
|
|
|
116 file, just double-click on that to open Visual Studio.
|
|
|
117
|
|
|
118 7. Build the LLVM Suite:
|
|
|
119
|
|
|
120 * The projects may still be built individually, but to build them all do
|
|
|
121 not just select all of them in batch build (as some are meant as
|
|
|
122 configuration projects), but rather select and build just the
|
|
|
123 ``ALL_BUILD`` project to build everything, or the ``INSTALL`` project,
|
|
|
124 which first builds the ``ALL_BUILD`` project, then installs the LLVM
|
|
|
125 headers, libs, and other useful things to the directory set by the
|
|
|
126 ``CMAKE_INSTALL_PREFIX`` setting when you first configured CMake.
|
|
|
127 * The Fibonacci project is a sample program that uses the JIT. Modify the
|
|
|
128 project's debugging properties to provide a numeric command line argument
|
|
|
129 or run it from the command line. The program will print the
|
|
|
130 corresponding fibonacci value.
|
|
|
131
|
|
|
132 8. Test LLVM in Visual Studio:
|
|
|
133
|
|
|
134 * If ``%PATH%`` does not contain GnuWin32, you may specify
|
|
|
135 ``LLVM_LIT_TOOLS_DIR`` on CMake for the path to GnuWin32.
|
|
|
136 * You can run LLVM tests by merely building the project "check". The test
|
|
|
137 results will be shown in the VS output window.
|
|
|
138
|
|
|
139 9. Test LLVM on the command line:
|
|
|
140
|
|
|
141 * The LLVM tests can be run by changing directory to the llvm source
|
|
|
142 directory and running:
|
|
|
143
|
|
|
144 .. code-block:: bat
|
|
|
145
|
|
|
146 C:\..\llvm> python ..\build\bin\llvm-lit --param build_config=Win32 --param build_mode=Debug --param llvm_site_config=../build/test/lit.site.cfg test
|
|
|
147
|
|
|
148 This example assumes that Python is in your PATH variable, you
|
|
|
149 have built a Win32 Debug version of llvm with a standard out of
|
|
|
150 line build. You should not see any unexpected failures, but will
|
|
|
151 see many unsupported tests and expected failures.
|
|
|
152
|
|
|
153 A specific test or test directory can be run with:
|
|
|
154
|
|
|
155 .. code-block:: bat
|
|
|
156
|
|
|
157 C:\..\llvm> python ..\build\bin\llvm-lit --param build_config=Win32 --param build_mode=Debug --param llvm_site_config=../build/test/lit.site.cfg test/path/to/test
|
|
|
158
|
|
|
159
|
|
|
160 An Example Using the LLVM Tool Chain
|
|
|
161 ====================================
|
|
|
162
|
|
|
163 1. First, create a simple C file, name it '``hello.c``':
|
|
|
164
|
|
|
165 .. code-block:: c
|
|
|
166
|
|
|
167 #include <stdio.h>
|
|
|
168 int main() {
|
|
|
169 printf("hello world\n");
|
|
|
170 return 0;
|
|
|
171 }
|
|
|
172
|
|
|
173 2. Next, compile the C file into an LLVM bitcode file:
|
|
|
174
|
|
|
175 .. code-block:: bat
|
|
|
176
|
|
|
177 C:\..> clang -c hello.c -emit-llvm -o hello.bc
|
|
|
178
|
|
|
179 This will create the result file ``hello.bc`` which is the LLVM bitcode
|
|
|
180 that corresponds the compiled program and the library facilities that
|
|
|
181 it required. You can execute this file directly using ``lli`` tool,
|
|
|
182 compile it to native assembly with the ``llc``, optimize or analyze it
|
|
|
183 further with the ``opt`` tool, etc.
|
|
|
184
|
|
|
185 Alternatively you can directly output an executable with clang with:
|
|
|
186
|
|
|
187 .. code-block:: bat
|
|
|
188
|
|
|
189 C:\..> clang hello.c -o hello.exe
|
|
|
190
|
|
|
191 The ``-o hello.exe`` is required because clang currently outputs ``a.out``
|
|
|
192 when neither ``-o`` nor ``-c`` are given.
|
|
|
193
|
|
|
194 3. Run the program using the just-in-time compiler:
|
|
|
195
|
|
|
196 .. code-block:: bat
|
|
|
197
|
|
|
198 C:\..> lli hello.bc
|
|
|
199
|
|
|
200 4. Use the ``llvm-dis`` utility to take a look at the LLVM assembly code:
|
|
|
201
|
|
|
202 .. code-block:: bat
|
|
|
203
|
|
|
204 C:\..> llvm-dis < hello.bc | more
|
|
|
205
|
|
|
206 5. Compile the program to object code using the LLC code generator:
|
|
|
207
|
|
|
208 .. code-block:: bat
|
|
|
209
|
|
|
210 C:\..> llc -filetype=obj hello.bc
|
|
|
211
|
|
|
212 6. Link to binary using Microsoft link:
|
|
|
213
|
|
|
214 .. code-block:: bat
|
|
|
215
|
|
|
216 C:\..> link hello.obj -defaultlib:libcmt
|
|
|
217
|
|
|
218 7. Execute the native code program:
|
|
|
219
|
|
|
220 .. code-block:: bat
|
|
|
221
|
|
|
222 C:\..> hello.exe
|
|
|
223
|
|
|
224
|
|
|
225 Common Problems
|
|
|
226 ===============
|
|
|
227 If you are having problems building or using LLVM, or if you have any other
|
|
|
228 general questions about LLVM, please consult the :doc:`Frequently Asked Questions
|
|
|
229 <FAQ>` page.
|
|
|
230
|
|
|
231
|
|
|
232 Links
|
|
|
233 =====
|
|
|
234 This document is just an **introduction** to how to use LLVM to do some simple
|
|
|
235 things... there are many more interesting and complicated things that you can
|
|
|
236 do that aren't documented here (but we'll gladly accept a patch if you want to
|
|
|
237 write something up!). For more information about LLVM, check out:
|
|
|
238
|
|
|
239 * `LLVM homepage <http://llvm.org/>`_
|
|
|
240 * `LLVM doxygen tree <http://llvm.org/doxygen/>`_
|
|
|
241
|
