dump declarations using clang Tooling API

CMakeLists.txt

cmake_minimum_required(VERSION 3.10)

# Set your project name and version
project(MyClangProject VERSION 1.0)

# Specify the C++ standard
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED True)
# add_link_options("-fuse-ld=lld")
set(NO_RTTI "-fno-rtti")
add_definitions(${NO_RTTI})

# Find LLVM
find_package(LLVM REQUIRED CONFIG)
message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")
message(STATUS "Using LLVMConfig.cmake in: ${LLVM_DIR}")

# Find Clang
find_package(Clang REQUIRED CONFIG)
message(STATUS "Found Clang")

# Add LLVM and Clang include directories
include_directories(${LLVM_INCLUDE_DIRS})
include_directories(${CLANG_INCLUDE_DIRS})

# Add LLVM and Clang definitions
add_definitions(${LLVM_DEFINITIONS})

# Your source files
set(SOURCE_FILES tool.cpp)

# Add the executable
add_executable(MyClangProject ${SOURCE_FILES})
install(TARGETS MyClangProject DESTINATION bin)

# Link LLVM and Clang libraries
llvm_map_components_to_libnames(llvm_libs Support core irreader AllTargetsCodeGens AllTargetsAsmParsers)
target_link_libraries(MyClangProject PRIVATE ${llvm_libs})

# If you're directly using Clang libraries, you might need to link them as well.
# This is an example to link against the Clang frontend and AST libraries.
target_link_libraries(MyClangProject PRIVATE
  clangAPINotes
  clangARCMigrate
  clangAST
  clangASTMatchers
  clangAnalysis
  clangAnalysisFlowSensitive
  clangAnalysisFlowSensitiveModels
  clangBasic
  clangCodeGen
  clangCrossTU
  clangDependencyScanning
  clangDirectoryWatcher
  clangDriver
  clangDynamicASTMatchers
  clangEdit
  clangExtractAPI
  clangFormat
  clangFrontend
  clangFrontendTool
  clangHandleCXX
  clangHandleLLVM
  clangIndex
  clangIndexSerialization
  clangInterpreter
  clangLex
  clangParse
  clangRewrite
  clangRewriteFrontend
  clangSema
  clangSerialization
  clangStaticAnalyzerCheckers
  clangStaticAnalyzerCore
  clangStaticAnalyzerFrontend
  clangSupport
  clangTooling
  clangToolingASTDiff
  clangToolingCore
  clangToolingInclusions
  clangToolingInclusionsStdlib
  clangToolingRefactoring
  clangToolingSyntax
  clangTransformer
)

tool.cpp

#include "clang/AST/DeclGroup.h"
#include <clang/Tooling/CommonOptionsParser.h>
#include <clang/Tooling/Tooling.h>
#include <clang/Frontend/CompilerInstance.h>
#include <clang/Frontend/FrontendActions.h>
#include <llvm/Support/CommandLine.h>
#include <llvm/Support/raw_ostream.h>

#include <memory>


using namespace clang;
using namespace clang::tooling;

class MyASTConsumer : public ASTConsumer {
public:
    explicit MyASTConsumer() {}

    virtual void HandleTranslationUnit(ASTContext &Context) override {
        // Here you can access the AST generated from the source code
        llvm::outs() << "Translation unit processed.\n";
    }

    virtual bool HandleTopLevelDecl(DeclGroupRef decl_group) override {
        llvm::outs() << "begin top level decl GROUP\n";
        for (auto decl: decl_group) {
            llvm::outs() << "begin top level decl\n";
            decl->print(llvm::outs(), 4);
            llvm::outs() << "\nend top level decl\n";
        }
        llvm::outs() << "end top level decl GROUP\n";
        return true;
    }
};

class MyFrontendAction : public ASTFrontendAction {
public:
    virtual std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI, StringRef file) override {
        return std::make_unique<MyASTConsumer>();
    }
};

int main(int argc, const char **argv) {
    llvm::cl::OptionCategory MyToolCategory("my-tool options");
    llvm::Expected<CommonOptionsParser> optionsParserRes = CommonOptionsParser::create(
        argc, argv, MyToolCategory);
    if (auto E = optionsParserRes.takeError()) {
        llvm::errs() << toString(std::move(E)) << "\n";
        return 1;
    }

    ClangTool Tool(
        optionsParserRes->getCompilations(),
        optionsParserRes->getSourcePathList());

    // Run the Clang Tool, creating a new FrontendAction.
    int result = Tool.run(newFrontendActionFactory<MyFrontendAction>().get());


    return result;
}