clang/examples/LLVMPrintFunctionNames/LLVMPrintFunctionNames.cpp

   1 //===- LLVMPrintFunctionNames.cpp
   2 //---------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Example clang plugin which simply prints the names of all the functions
  11 // within the generated LLVM code.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "clang/AST/AST.h"
  16 #include "clang/AST/ASTConsumer.h"
  17 #include "clang/AST/RecursiveASTVisitor.h"
  18 #include "clang/Frontend/CompilerInstance.h"
  19 #include "clang/Frontend/FrontendPluginRegistry.h"
  20 #include "clang/Sema/Sema.h"
  21 #include "llvm/IR/Module.h"
  22 #include "llvm/IR/PassManager.h"
  23 #include "llvm/Passes/OptimizationLevel.h"
  24 #include "llvm/Passes/PassBuilder.h"
  25 #include "llvm/Support/raw_ostream.h"
  26 using namespace clang;
  27
  28 namespace {
  29
  30 class PrintPass final : public llvm::AnalysisInfoMixin<PrintPass> {
  31   friend struct llvm::AnalysisInfoMixin<PrintPass>;
  32
  33 public:
  34   using Result = llvm::PreservedAnalyses;
  35
  36   Result run(llvm::Module &M, llvm::ModuleAnalysisManager &MAM) {
  37     for (auto &F : M)
  38       llvm::outs() << "[PrintPass] Found function: " << F.getName() << "\n";
  39     return llvm::PreservedAnalyses::all();
  40   }
  41   static bool isRequired() { return true; }
  42 };
  43
  44 void PrintCallback(llvm::PassBuilder &PB) {
  45   PB.registerPipelineStartEPCallback(
  46       [](llvm::ModulePassManager &MPM, llvm::OptimizationLevel) {
  47         MPM.addPass(PrintPass());
  48       });
  49 }
  50
  51 class LLVMPrintFunctionsConsumer : public ASTConsumer {
  52 public:
  53   LLVMPrintFunctionsConsumer(CompilerInstance &Instance) {
  54     Instance.getCodeGenOpts().PassBuilderCallbacks.push_back(PrintCallback);
  55   }
  56 };
  57
  58 class LLVMPrintFunctionNamesAction : public PluginASTAction {
  59 protected:
  60   std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
  61                                                  llvm::StringRef) override {
  62     return std::make_unique<LLVMPrintFunctionsConsumer>(CI);
  63   }
  64   bool ParseArgs(const CompilerInstance &,
  65                  const std::vector<std::string> &) override {
  66     return true;
  67   }
  68   PluginASTAction::ActionType getActionType() override {
  69     return AddBeforeMainAction;
  70   }
  71 };
  72
  73 } // namespace
  74
  75 static FrontendPluginRegistry::Add<LLVMPrintFunctionNamesAction>
  76     X("llvm-print-fns", "print function names, llvm level");