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LLVM IR字符串类型拼接方法是怎样的

发表于：2025-02-21 作者：千家信息网编辑

千家信息网最后更新 2025年02月21日，本篇文章为大家展示了LLVM IR字符串类型拼接方法是怎样的，内容简明扼要并且容易理解，绝对能使你眼前一亮，通过这篇文章的详细介绍希望你能有所收获。IR语义为将字符串与整型进行拼接操作；方法虽然笨拙，

千家信息网最后更新 2025年02月21日LLVM IR字符串类型拼接方法是怎样的

本篇文章为大家展示了LLVM IR字符串类型拼接方法是怎样的，内容简明扼要并且容易理解，绝对能使你眼前一亮，通过这篇文章的详细介绍希望你能有所收获。

IR语义为将字符串与整型进行拼接操作；方法虽然笨拙，但能够满足目前的业务需求，今分享出来供大家交流与参考。代码运行环境为LLVM6.0。关键字：LLVM、字符串、char*、string、拼接、concat、IR

#include "llvm/IR/IRBuilder.h"#include "llvm/IR/Verifier.h"#include "llvm/Support/TargetSelect.h"#include "llvm/ExecutionEngine/ExecutionEngine.h"#include "llvm/IR/LLVMContext.h"#include "llvm/IR/Module.h"#include "llvm/IR/Function.h"#include "llvm/IR/BasicBlock.h"#include "llvm/ExecutionEngine/MCJIT.h"#include "llvm/IR/TypeBuilder.h"#include #include #include #include #include #include #include #include #include #include #include using namespace llvm;using namespace std;//字符串拼接操作放在C++端进行char* javaMethodAdd( int x, char * str) {                        cout << "arg x:"<< x << endl;        string str1 = str;        string xstr = to_string(x);        str1+= xstr;        char *st1 = const_cast(str1.c_str()) ;        return st1;}int main() {        llvm::LLVMContext *context = new llvm::LLVMContext();        llvm::Module *module = new llvm::Module("test", *context);        std::vector arg_types = {                llvm::Type::getInt32Ty(*context),                llvm::Type::getInt32Ty(*context)};//函数参数，返回类型为char指针        llvm::FunctionType *ftype = llvm::FunctionType::get(                llvm::Type::getInt8PtrTy(*context), arg_types,false);        llvm::Function *func = llvm::Function::Create(                ftype, llvm::GlobalValue::LinkageTypes::ExternalLinkage, "my_func", module);                        func->setCallingConv(llvm::CallingConv::C);        llvm::BasicBlock *bb = llvm::BasicBlock::(*context, "entry", func);        llvm::IRBuilder<> builder(*context);        builder.SetInsertPoint(bb);//获取传入的参数        llvm::Argument *arg0 = func->arg_begin() + 0;        llvm::Argument *arg1 = func->arg_begin() + 1;                        //string begain------------------        //LLVM字符串常量Constant *const_array_str = ConstantDataArray::getString(*context, "beeeeegineeee", false);        //申请内存空间        AllocaInst* const_array_addr = builder.CreateAlloca(const_array_str->getType(),                                    ConstantExpr::getSizeOf(const_array_str->getType()),"temaddr");const_array_addr->setAlignment (1);                        std::vector index_vector;        index_vector.push_back(ConstantInt::get(Type::getInt32Ty(*context), 0));                auto valueAsPtr = builder.CreateGEP(const_array_addr, index_vector, "tmp");                // 存储字符串到内存空间        StoreInst *sist = builder.CreateStore(const_array_str, valueAsPtr);        sist->setAlignment (1);                 index_vector.push_back(ConstantInt::get(Type::getInt64Ty(*context), 0));        //创建指向字符串存储内存空间的指针auto  retRes = builder.CreateInBoundsGEP( const_array_str->getType(), const_array_addr, index_vector, "tmpstr");                //string end---------------------------                //llvm::Value *result = builder.CreateAdd(arg0, arg1, "result");        llvm::Value* result = builder.CreateBinOp(llvm::Instruction::Add,                                   arg0, arg1, "result");        //忽略函数名称（可改为任意的）        FunctionType* double_add_double_type = TypeBuilder::get(*context);        Function* fdouble_add_double = cast(module->getOrInsertFunction("double_add_double", double_add_double_type));        std::vector args;        args.push_back(result);        args.push_back(retRes);        Value* ret = builder.CreateCall(fdouble_add_double, args);                builder.CreateRet(ret);llvm::InitializeNativeTarget();        llvm::InitializeNativeTargetAsmPrinter();        llvm::InitializeNativeTargetAsmParser();        //创建执行引擎 llvm::ExecutionEngine *ee =        llvm::EngineBuilder(std::unique_ptr(module)).setEngineKind(llvm::EngineKind::JIT).create();   printf("executed  .........segment........\n");        //LLVM函数与C++函数映射 ee->addGlobalMapping(fdouble_add_double, (char*)javaMethodAdd);        ee->finalizeObject();char* (*add)(int, int) = (char* (*)(int, int))ee->getFunctionAddress("my_func");        printf("Result: %s\n", add(43, 10));        return 0;}