--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/llvm-extract/llvm-extract.cpp	Thu Dec 12 13:56:28 2013 +0900
@@ -0,0 +1,285 @@
+//===- llvm-extract.cpp - LLVM function extraction utility ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This utility changes the input module to only contain a single function,
+// which is primarily used for debugging transformations.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/Assembly/PrintModulePass.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IRReader/IRReader.h"
+#include "llvm/PassManager.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/Support/Regex.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/SystemUtils.h"
+#include "llvm/Support/ToolOutputFile.h"
+#include "llvm/Transforms/IPO.h"
+#include <memory>
+using namespace llvm;
+
+// InputFilename - The filename to read from.
+static cl::opt<std::string>
+InputFilename(cl::Positional, cl::desc("<input bitcode file>"),
+              cl::init("-"), cl::value_desc("filename"));
+
+static cl::opt<std::string>
+OutputFilename("o", cl::desc("Specify output filename"),
+               cl::value_desc("filename"), cl::init("-"));
+
+static cl::opt<bool>
+Force("f", cl::desc("Enable binary output on terminals"));
+
+static cl::opt<bool>
+DeleteFn("delete", cl::desc("Delete specified Globals from Module"));
+
+// ExtractFuncs - The functions to extract from the module.
+static cl::list<std::string>
+ExtractFuncs("func", cl::desc("Specify function to extract"),
+             cl::ZeroOrMore, cl::value_desc("function"));
+
+// ExtractRegExpFuncs - The functions, matched via regular expression, to
+// extract from the module.
+static cl::list<std::string>
+ExtractRegExpFuncs("rfunc", cl::desc("Specify function(s) to extract using a "
+                                     "regular expression"),
+                   cl::ZeroOrMore, cl::value_desc("rfunction"));
+
+// ExtractAlias - The alias to extract from the module.
+static cl::list<std::string>
+ExtractAliases("alias", cl::desc("Specify alias to extract"),
+               cl::ZeroOrMore, cl::value_desc("alias"));
+
+
+// ExtractRegExpAliases - The aliases, matched via regular expression, to
+// extract from the module.
+static cl::list<std::string>
+ExtractRegExpAliases("ralias", cl::desc("Specify alias(es) to extract using a "
+                                        "regular expression"),
+                     cl::ZeroOrMore, cl::value_desc("ralias"));
+
+// ExtractGlobals - The globals to extract from the module.
+static cl::list<std::string>
+ExtractGlobals("glob", cl::desc("Specify global to extract"),
+               cl::ZeroOrMore, cl::value_desc("global"));
+
+// ExtractRegExpGlobals - The globals, matched via regular expression, to
+// extract from the module...
+static cl::list<std::string>
+ExtractRegExpGlobals("rglob", cl::desc("Specify global(s) to extract using a "
+                                       "regular expression"),
+                     cl::ZeroOrMore, cl::value_desc("rglobal"));
+
+static cl::opt<bool>
+OutputAssembly("S",
+               cl::desc("Write output as LLVM assembly"), cl::Hidden);
+
+int main(int argc, char **argv) {
+  // Print a stack trace if we signal out.
+  sys::PrintStackTraceOnErrorSignal();
+  PrettyStackTraceProgram X(argc, argv);
+
+  LLVMContext &Context = getGlobalContext();
+  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
+  cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");
+
+  // Use lazy loading, since we only care about selected global values.
+  SMDiagnostic Err;
+  OwningPtr<Module> M;
+  M.reset(getLazyIRFileModule(InputFilename, Err, Context));
+
+  if (M.get() == 0) {
+    Err.print(argv[0], errs());
+    return 1;
+  }
+
+  // Use SetVector to avoid duplicates.
+  SetVector<GlobalValue *> GVs;
+
+  // Figure out which aliases we should extract.
+  for (size_t i = 0, e = ExtractAliases.size(); i != e; ++i) {
+    GlobalAlias *GA = M->getNamedAlias(ExtractAliases[i]);
+    if (!GA) {
+      errs() << argv[0] << ": program doesn't contain alias named '"
+             << ExtractAliases[i] << "'!\n";
+      return 1;
+    }
+    GVs.insert(GA);
+  }
+
+  // Extract aliases via regular expression matching.
+  for (size_t i = 0, e = ExtractRegExpAliases.size(); i != e; ++i) {
+    std::string Error;
+    Regex RegEx(ExtractRegExpAliases[i]);
+    if (!RegEx.isValid(Error)) {
+      errs() << argv[0] << ": '" << ExtractRegExpAliases[i] << "' "
+        "invalid regex: " << Error;
+    }
+    bool match = false;
+    for (Module::alias_iterator GA = M->alias_begin(), E = M->alias_end();
+         GA != E; GA++) {
+      if (RegEx.match(GA->getName())) {
+        GVs.insert(&*GA);
+        match = true;
+      }
+    }
+    if (!match) {
+      errs() << argv[0] << ": program doesn't contain global named '"
+             << ExtractRegExpAliases[i] << "'!\n";
+      return 1;
+    }
+  }
+
+  // Figure out which globals we should extract.
+  for (size_t i = 0, e = ExtractGlobals.size(); i != e; ++i) {
+    GlobalValue *GV = M->getNamedGlobal(ExtractGlobals[i]);
+    if (!GV) {
+      errs() << argv[0] << ": program doesn't contain global named '"
+             << ExtractGlobals[i] << "'!\n";
+      return 1;
+    }
+    GVs.insert(GV);
+  }
+
+  // Extract globals via regular expression matching.
+  for (size_t i = 0, e = ExtractRegExpGlobals.size(); i != e; ++i) {
+    std::string Error;
+    Regex RegEx(ExtractRegExpGlobals[i]);
+    if (!RegEx.isValid(Error)) {
+      errs() << argv[0] << ": '" << ExtractRegExpGlobals[i] << "' "
+        "invalid regex: " << Error;
+    }
+    bool match = false;
+    for (Module::global_iterator GV = M->global_begin(),
+           E = M->global_end(); GV != E; GV++) {
+      if (RegEx.match(GV->getName())) {
+        GVs.insert(&*GV);
+        match = true;
+      }
+    }
+    if (!match) {
+      errs() << argv[0] << ": program doesn't contain global named '"
+             << ExtractRegExpGlobals[i] << "'!\n";
+      return 1;
+    }
+  }
+
+  // Figure out which functions we should extract.
+  for (size_t i = 0, e = ExtractFuncs.size(); i != e; ++i) {
+    GlobalValue *GV = M->getFunction(ExtractFuncs[i]);
+    if (!GV) {
+      errs() << argv[0] << ": program doesn't contain function named '"
+             << ExtractFuncs[i] << "'!\n";
+      return 1;
+    }
+    GVs.insert(GV);
+  }
+  // Extract functions via regular expression matching.
+  for (size_t i = 0, e = ExtractRegExpFuncs.size(); i != e; ++i) {
+    std::string Error;
+    StringRef RegExStr = ExtractRegExpFuncs[i];
+    Regex RegEx(RegExStr);
+    if (!RegEx.isValid(Error)) {
+      errs() << argv[0] << ": '" << ExtractRegExpFuncs[i] << "' "
+        "invalid regex: " << Error;
+    }
+    bool match = false;
+    for (Module::iterator F = M->begin(), E = M->end(); F != E;
+         F++) {
+      if (RegEx.match(F->getName())) {
+        GVs.insert(&*F);
+        match = true;
+      }
+    }
+    if (!match) {
+      errs() << argv[0] << ": program doesn't contain global named '"
+             << ExtractRegExpFuncs[i] << "'!\n";
+      return 1;
+    }
+  }
+
+  // Materialize requisite global values.
+  if (!DeleteFn)
+    for (size_t i = 0, e = GVs.size(); i != e; ++i) {
+      GlobalValue *GV = GVs[i];
+      if (GV->isMaterializable()) {
+        std::string ErrInfo;
+        if (GV->Materialize(&ErrInfo)) {
+          errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
+          return 1;
+        }
+      }
+    }
+  else {
+    // Deleting. Materialize every GV that's *not* in GVs.
+    SmallPtrSet<GlobalValue *, 8> GVSet(GVs.begin(), GVs.end());
+    for (Module::global_iterator I = M->global_begin(), E = M->global_end();
+         I != E; ++I) {
+      GlobalVariable *G = I;
+      if (!GVSet.count(G) && G->isMaterializable()) {
+        std::string ErrInfo;
+        if (G->Materialize(&ErrInfo)) {
+          errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
+          return 1;
+        }
+      }
+    }
+    for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) {
+      Function *F = I;
+      if (!GVSet.count(F) && F->isMaterializable()) {
+        std::string ErrInfo;
+        if (F->Materialize(&ErrInfo)) {
+          errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
+          return 1;
+        }
+      }
+    }
+  }
+
+  // In addition to deleting all other functions, we also want to spiff it
+  // up a little bit.  Do this now.
+  PassManager Passes;
+  Passes.add(new DataLayout(M.get())); // Use correct DataLayout
+
+  std::vector<GlobalValue*> Gvs(GVs.begin(), GVs.end());
+
+  Passes.add(createGVExtractionPass(Gvs, DeleteFn));
+  if (!DeleteFn)
+    Passes.add(createGlobalDCEPass());           // Delete unreachable globals
+  Passes.add(createStripDeadDebugInfoPass());    // Remove dead debug info
+  Passes.add(createStripDeadPrototypesPass());   // Remove dead func decls
+
+  std::string ErrorInfo;
+  tool_output_file Out(OutputFilename.c_str(), ErrorInfo, sys::fs::F_Binary);
+  if (!ErrorInfo.empty()) {
+    errs() << ErrorInfo << '\n';
+    return 1;
+  }
+
+  if (OutputAssembly)
+    Passes.add(createPrintModulePass(&Out.os()));
+  else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
+    Passes.add(createBitcodeWriterPass(Out.os()));
+
+  Passes.run(*M.get());
+
+  // Declare success.
+  Out.keep();
+
+  return 0;
+}