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#include <memory>
#include <vector>
#include <llvm/IR/IRBuilder.h>
#include <llvm/IR/Verifier.h>
#include "DeclNode.hh"
#include "FunctionNode.hh"
#include "Log.hh"
namespace pcc {
FunctionNode::FunctionNode(
Context* context, std::string name, std::list<Declaration> arguments,
std::list<std::shared_ptr<BaseNode>> LocalDeclarations,
std::shared_ptr<Type> type, std::shared_ptr<StatementListNode> body)
: BaseNode(context)
, name_(name)
, arguments_(arguments)
, LocalDeclarations_(LocalDeclarations)
, type_(type)
, locals_(context->GetGlobals())
, body_(body) {
for (auto& decl : LocalDeclarations_) {
std::shared_ptr<VarDeclNode> VarDecl =
std::dynamic_pointer_cast<VarDeclNode>(decl);
if (VarDecl != nullptr) {
// set the inherited attribute
VarDecl->SetScope(&locals_);
}
}
}
Value FunctionNode::CodeGen() {
llvm::Module* module = context_->GetModule();
llvm::IRBuilder<>* builder = context_->GetBuilder();
std::vector<std::shared_ptr<Type>> params(arguments_.size());
std::transform(arguments_.cbegin(), arguments_.cend(), params.begin(),
[](const Declaration& decl) { return std::get<1>(decl); });
std::shared_ptr<FunctionType> type =
context_->GetTypeManager()->CreateFunctionType(type_, params);
context_->AddFunctionType(name_, type);
llvm::FunctionType* LLVMType =
llvm::cast<llvm::FunctionType>(type->GetLLVMType());
llvm::Function* function = llvm::Function::Create(
LLVMType, llvm::GlobalValue::ExternalLinkage, name_, *module);
function->setCallingConv(llvm::CallingConv::C);
llvm::BasicBlock* block =
llvm::BasicBlock::Create(GlobalLLVMContext, name_, function);
Log(LogLevel::PCC_INFO, "generating function %s of type %s", name_.c_str(),
type->GetCommonName());
builder->SetInsertPoint(block);
// alloc arguments
llvm::Function::arg_iterator ArgIt = function->arg_begin();
for (auto& arg : arguments_) {
Value ArgValue = builder->CreateAlloca(std::get<1>(arg)->GetLLVMType());
builder->CreateStore(ArgIt++, ArgValue);
locals_.Add(std::get<0>(arg), {std::get<1>(arg), ArgValue});
}
// alloc local variables
for (auto& decl : LocalDeclarations_) {
decl->CodeGen();
}
// create a variable with the same name as the function for return value
Value rv = builder->CreateAlloca(type_->GetLLVMType());
locals_.Add(name_, {type_, rv});
// push the function scope variables
context_->PushScope(&locals_);
body_->CodeGen();
builder->CreateRet(builder->CreateLoad(type_->GetLLVMType(), rv));
context_->PopScope();
std::string msg;
llvm::raw_string_ostream MsgStream(msg);
llvm::verifyFunction(*function, &MsgStream);
MsgStream.flush();
if (!msg.empty()) {
Log(LogLevel::PCC_INFO, "%s", msg.c_str());
}
return nullptr;
}
} // namespace pcc
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