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 
47   LLVM_DEBUG(dbgs() << "Global DCE...\n");
48 
49   {
50     ModuleAnalysisManager MAM;
51     ModulePassManager MPM;
52 
53     PassInstrumentationCallbacks PIC;
54     MAM.registerPass([&] { return PassInstrumentationAnalysis(&PIC); });
55 
56     MPM.addPass(GlobalDCEPass());
57     MPM.addPass(StripDeadPrototypesPass());
58     MPM.run(*CM, MAM);
59   }
60 
61   LLVM_DEBUG(dbgs() << "Write to file '" << Dumpfile << "'...\n");
62 
63   std::unique_ptr<ToolOutputFile> Out;
64   std::error_code EC;
65   Out.reset(new ToolOutputFile(Dumpfile, EC, sys::fs::OF_None));
66   if (EC) {
67     errs() << EC.message() << '\n';
68     return;
69   }
70 
71   CM->print(Out->os(), nullptr);
72   Out->keep();
73   LLVM_DEBUG(dbgs() << "Dump file " << Dumpfile << " written successfully\n");
74 }
75 
76 class DumpFunctionWrapperPass : public FunctionPass {
77 private:
78   DumpFunctionWrapperPass(const DumpFunctionWrapperPass &) = delete;
79   const DumpFunctionWrapperPass &
80   operator=(const DumpFunctionWrapperPass &) = delete;
81 
82   std::string Suffix;
83 
84 public:
85   static char ID;
86 
87   explicit DumpFunctionWrapperPass() : FunctionPass(ID), Suffix("-dump") {}
88 
89   explicit DumpFunctionWrapperPass(std::string Suffix)
90       : FunctionPass(ID), Suffix(std::move(Suffix)) {}
91 
92   /// @name FunctionPass interface
93   //@{
94   virtual void getAnalysisUsage(llvm::AnalysisUsage &AU) const override {
95     AU.setPreservesAll();
96   }
97 
98   virtual bool runOnFunction(llvm::Function &F) override {
99     runDumpFunction(F, Suffix);
100     return false;
101   }
102   //@}
103 };
104 
105 char DumpFunctionWrapperPass::ID;
106 } // namespace
107 
108 FunctionPass *polly::createDumpFunctionWrapperPass(std::string Suffix) {
109   return new DumpFunctionWrapperPass(std::move(Suffix));
110 }
111 
112 llvm::PreservedAnalyses DumpFunctionPass::run(Function &F,
113                                               FunctionAnalysisManager &AM) {
114   runDumpFunction(F, Suffix);
115   return PreservedAnalyses::all();
116 }
117 
118 INITIALIZE_PASS_BEGIN(DumpFunctionWrapperPass, "polly-dump-function",
119                       "Polly - Dump Function", false, false)
120 INITIALIZE_PASS_END(DumpFunctionWrapperPass, "polly-dump-function",
121                     "Polly - Dump Function", false, false)
122