c++怎么编写一个LLVM/Clang的前端插件_C++编译器扩展与插件开发实践

cmake_minimum_required(VERSION 3.14)
project(MyClangTool)

find_package(LLVM REQUIRED CONFIG)
find_package(Clang REQUIRED CONFIG)

message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")
message(STATUS "Using LLVMConfig.cmake in: ${LLVM_DIR}")

include_directories(${LLVM_INCLUDE_DIRS} ${CLANG_INCLUDE_DIRS})
add_definitions(${LLVM_DEFINITIONS})

add_executable(my-tool MyTool.cpp)
target_link_libraries(my-tool
    clangBasic
    clangAST
    clangFrontend
    clangTooling
    LLVMCore
)

#include "clang/Tooling/CommonOptionsParser.h"
#include "clang/Tooling/Tooling.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/Decl.h"
#include "clang/Frontend/MultiplexConsumer.h"

using namespace clang;
using namespace clang::tooling;

// 定义一个 AST 访问器，遍历函数声明
class FunctionPrinter : public RecursiveASTVisitor<FunctionPrinter> {
public:
  explicit FunctionPrinter(ASTContext *Ctx) : Context(Ctx) {}

  bool VisitFunctionDecl(FunctionDecl *FD) {
    if (FD->hasBody()) {
      llvm::outs() << "Found function: " << FD->getNameAsString() << "\n";
    }
    return true;
  }

private:
  ASTContext *Context;
};

// 自定义 ASTConsumer
class MyASTConsumer : public ASTConsumer {
public:
  MyASTConsumer(ASTContext *Ctx) : Visitor(Ctx) {}

  void HandleTranslationUnit(ASTContext &Context) override {
    Visitor.TraverseDecl(Context.getTranslationUnitDecl());
  }

private:
  FunctionPrinter Visitor;
};

// 前端动作：当 Clang 解析文件时触发
class MyFrontendAction : public ASTFrontendAction {
public:
  std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
                                                   StringRef file) override {
    return std::make_unique<MyASTConsumer>(&CI.getASTContext());
  }
};

int main(int argc, const char **argv) {
  CommonOptionsParser OptionsParser(argc, argv, llvm::cl::GeneralCategory);
  ClangTool Tool(OptionsParser.getCompilations(),
                 OptionsParser.getSourcePathList());

  return Tool.run(newFrontendActionFactory<MyFrontendAction>().get());
}

MatchFinder Finder;
Finder.addMatcher(functionDecl(hasName("foo")).bind("fn"), &Handler);

// 在 run() 中调用 Finder.match(*Decl, *Context);