llvm - helloworld
環境設置 # ubuntu體系：sudo apt-get install llvm MAC: brew install llvm makefile (MAC) # BIN_PATH=/usr/local/Cellar/llvm/3.6.1/bin/ export PATH:=$(PATH):$(BIN_PATH) LLVM_CONFIG=llvm-config FLAGS= --cxxflags --ldflags --system-libs --libs core toy: toy.cpp clang++ -g -O3 toy.cpp `$(LLVM_CONFIG) $(FLAGS)` -o toy clean: rm -f toy top module # #include "llvm/LLVMContext.h" #include "llvm/Module.h" #include "llvm/Support/IRBuilder.h" int main() { llvm::LLVMContext& context = llvm::getGlobalContext(); llvm::Module* module = new llvm::Module("top", context); llvm::IRBuilder<> builder(context); module->dump( ); } function # 宣告function # 無參數 # llvm::FunctionType *funcType = llvm::FunctionType::get(builder.getInt32Ty(), false); llvm::Function *mainFunc = llvm::Function::Create(funcType, llvm::Function::ExternalLinkage, "main", module); 有參數 # std::vector< llvm::Type* > putsArgs; putsArgs.push_back(builder.getInt8Ty()->getPointerTo()); llvm::ArrayRef< llvm::Type* > argsRef(putsArgs); llvm::FunctionType *putsType = llvm::FunctionType::get(builder.getInt32Ty(), argsRef, false); 定義function # 引用已有的function # llvm::Constant *putsFunc = module->getOrInsertFunction("puts", putsType); 創造新的function # llvm::BasicBlock *entry = llvm::BasicBlock::Create(context, "entrypoint", mainFunc); builder.SetInsertPoint(entry); 增添function內容