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