polly/lib/Support/DumpFunctionPass.cpp

   1 //===------ DumpFunctionPass.cpp --------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Write a function to a file.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "polly/Support/DumpFunctionPass.h"
  14 #include "llvm/IR/Module.h"
  15 #include "llvm/Pass.h"
  16 #include "llvm/Support/Debug.h"
  17 #include "llvm/Support/FileSystem.h"
  18 #include "llvm/Support/Path.h"
  19 #include "llvm/Support/ToolOutputFile.h"
  20 #include "llvm/Transforms/IPO/GlobalDCE.h"
  21 #include "llvm/Transforms/IPO/StripDeadPrototypes.h"
  22 #include "llvm/Transforms/Utils/Cloning.h"
  23
  24 #define DEBUG_TYPE "polly-dump-func"
  25
  26 using namespace llvm;
  27 using namespace polly;
  28
  29 namespace {
  30
  31 static void runDumpFunction(llvm::Function &F, StringRef Suffix) {
  32   StringRef FName = F.getName();
  33   Module *M = F.getParent();
  34
  35   StringRef ModuleName = M->getName();
  36   StringRef Stem = sys::path::stem(ModuleName);
  37   std::string Dumpfile = (Twine(Stem) + "-" + FName + Suffix + ".ll").str();
  38   LLVM_DEBUG(dbgs() << "Dumping function '" << FName << "' to '" << Dumpfile
  39                     << "'...\n");
  40
  41   ValueToValueMapTy VMap;
  42   auto ShouldCloneDefinition = [&F](const GlobalValue *GV) -> bool {
  43     return GV == &F;
  44   };
  45   std::unique_ptr<Module> CM = CloneModule(*M, VMap, ShouldCloneDefinition);
  46   Function *NewF = cast<Function>(VMap.lookup(&F));
  47   assert(NewF && "Expected selected function to be cloned");
  48
  49   LLVM_DEBUG(dbgs() << "Global DCE...\n");
  50
  51   // Stop F itself from being pruned
  52   GlobalValue::LinkageTypes OrigLinkage = NewF->getLinkage();
  53   NewF->setLinkage(GlobalValue::ExternalLinkage);
  54
  55   {
  56     ModuleAnalysisManager MAM;
  57     ModulePassManager MPM;
  58
  59     PassInstrumentationCallbacks PIC;
  60     MAM.registerPass([&] { return PassInstrumentationAnalysis(&PIC); });
  61
  62     MPM.addPass(GlobalDCEPass());
  63     MPM.addPass(StripDeadPrototypesPass());
  64     MPM.run(*CM, MAM);
  65   }
  66
  67   // Restore old linkage
  68   NewF->setLinkage(OrigLinkage);
  69
  70   LLVM_DEBUG(dbgs() << "Write to file '" << Dumpfile << "'...\n");
  71
  72   std::unique_ptr<ToolOutputFile> Out;
  73   std::error_code EC;
  74   Out.reset(new ToolOutputFile(Dumpfile, EC, sys::fs::OF_None));
  75   if (EC) {
  76     errs() << EC.message() << '\n';
  77     return;
  78   }
  79
  80   CM->print(Out->os(), nullptr);
  81   Out->keep();
  82   LLVM_DEBUG(dbgs() << "Dump file " << Dumpfile << " written successfully\n");
  83 }
  84
  85 class DumpFunctionWrapperPass final : public FunctionPass {
  86 private:
  87   DumpFunctionWrapperPass(const DumpFunctionWrapperPass &) = delete;
  88   const DumpFunctionWrapperPass &
  89   operator=(const DumpFunctionWrapperPass &) = delete;
  90
  91   std::string Suffix;
  92
  93 public:
  94   static char ID;
  95
  96   explicit DumpFunctionWrapperPass() : FunctionPass(ID), Suffix("-dump") {}
  97
  98   explicit DumpFunctionWrapperPass(std::string Suffix)
  99       : FunctionPass(ID), Suffix(std::move(Suffix)) {}
 100
 101   /// @name FunctionPass interface
 102   //@{
 103   void getAnalysisUsage(llvm::AnalysisUsage &AU) const override {
 104     AU.setPreservesAll();
 105   }
 106
 107   bool runOnFunction(llvm::Function &F) override {
 108     runDumpFunction(F, Suffix);
 109     return false;
 110   }
 111   //@}
 112 };
 113
 114 char DumpFunctionWrapperPass::ID;
 115 } // namespace
 116
 117 FunctionPass *polly::createDumpFunctionWrapperPass(std::string Suffix) {
 118   return new DumpFunctionWrapperPass(std::move(Suffix));
 119 }
 120
 121 llvm::PreservedAnalyses DumpFunctionPass::run(Function &F,
 122                                               FunctionAnalysisManager &AM) {
 123   runDumpFunction(F, Suffix);
 124   return PreservedAnalyses::all();
 125 }
 126
 127 INITIALIZE_PASS_BEGIN(DumpFunctionWrapperPass, "polly-dump-function",
 128                       "Polly - Dump Function", false, false)
 129 INITIALIZE_PASS_END(DumpFunctionWrapperPass, "polly-dump-function",
 130                     "Polly - Dump Function", false, false)