llvm学习日记十三：PassManager 注册pass

参考：http://www.alonemonkey.com/2016/12/21/learning-llvm/

一、目的：

写入opt和clang的命令参数，可以直接参数指定调用

二、使用pass

把上一小节的pass稍加修改

创建头文件：include/llvm/Transforms/CountOpcode/CountOpcode.h

#include "llvm/IR/Function.h"
#include "llvm/Pass.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Instructions.h"
#include "llvm/InitializePasses.h"

#define DEBUG_TYPE "opcodecounter"

namespace llvm {
    FunctionPass *createCountOpcodePass();
//    void initializeCountOpcodePass(PassRegistry &Registry);
}

cpp文件：lib/Transforms/CountOpcode/CountOpcode.cpp

#include "llvm/Transforms/CountOpcode/CountOpcode.h"

using namespace llvm;

static cl::opt<bool> EnableCountOpcode("opcodeCounter2", cl::init(false),
                                 cl::desc("Count opcode number"));

namespace llvm {
    struct CountOpcode : public FunctionPass {
        std::map<std::string,int> opcodeCounter;
        static char ID;
        CountOpcode() : FunctionPass(ID){}
        virtual bool runOnFunction(Function &F) {
            if(!EnableCountOpcode){
                return false;
            }
            errs()<<"FunctionName:"<<F.getName()<<"\n";
            for(Function::iterator bb = F.begin(),e = F.end();bb!=e;++bb){
                for(BasicBlock::iterator i = bb->begin(),ie = bb->end();i!=ie;++i){
                    if(opcodeCounter.find(i->getOpcodeName()) == opcodeCounter.end()){
                        opcodeCounter[i->getOpcodeName()] =1;
                    }else{
                        opcodeCounter[i->getOpcodeName()] +=1;
                    }
                }
            }
            std::map<std::string,int>::iterator ib = opcodeCounter.begin();
            std::map<std::string,int>::iterator ie = opcodeCounter.end();
            while (ib != ie) {
                errs() << ib->first << " : " << ib->second << "\n";
                ib++;
            }
            errs()<<"\n";
            opcodeCounter.clear();
            return false;
        }
        
    };
    FunctionPass * createCountOpcodePass(){
        return new CountOpcode();
    }

}

char CountOpcode::ID = 0;
//static RegisterPass<CountOpcode> X("opcodeCounter", "Count opcode number", false, false);
INITIALIZE_PASS(CountOpcode, "opcodeCounter", "Count opcode number", false, false)

创建LLVMBuild.txt ： lib/Transforms/CountOpcode/LLVMBuild.txt

[component_0]
type = Library
name = CountOpcode
parent = Transforms
library_name = CountOpcode

创建CMakeLists.txt ： lib/Transforms/CountOpcode/CMakeLists.txt


add_llvm_library( LLVMCountOpcode
  CountOpcode.cpp

  DEPENDS
  intrinsics_gen
  )

lib/Transforms/CMakeLists.txt

add_subdirectory(CountOpcode)

lib/Transforms/LLVMBuild.txt 加上我们的pass

[common]
subdirectories = AggressiveInstCombine Coroutines IPO InstCombine Instrumentation Scalar Utils Vectorize ObjCARC CountOpcode

PassManager 注册
lib/Transforms/IPO/PassManagerBuilder.cpp 添加头文件：

#include "llvm/Transforms/CountOpcode/CountOpcode.h"

lib/Transforms/IPO/PassManagerBuilder.cpp 函数 populateModulePassManager 添加：

MPM.add(createCountOpcode());

lib/Transforms/IPO/LLVMBuild.txt 添加：

required_libraries = AggressiveInstCombine Analysis BitReader BitWriter Core InstCombine IRReader Linker Object ProfileData Scalar Support TransformUtils Vectorize Instrumentation CountOpcode

相关头文件修改：
llvm/LinkAllPasses.h 头文件添加：
#include "llvm/Transforms/CountOpcode/CountOpcode.h"
(void) llvm::createCountOpcodePass();
llvm/InitializePasses.h 头文件添加：
void initializeCountOpcodePass(PassRegistry&);
opt命令参数添加：
initializeCountOpcodePass(Registry);