c-compiler/src/codegen.cpp
2026-04-10 16:58:27 +03:00

134 lines
4.2 KiB
C++

#include "codegen.h"
#include "ast.h"
#include "types.h"
#include <llvm/IR/Module.h>
#include <llvm/IR/Verifier.h>
#include <memory>
#include <iostream>
namespace codegen {
Scope Scope::with_lvalue() {
return Scope{ this->values, true };
}
}
namespace AST {
codegen::StackValue IntLiteralExpression::codegen(codegen::Builder& builder, codegen::Scope& scope) {
auto ty = builder.builder->getInt32Ty();
auto stack_type = new types::FundamentalType{ types::FundamentalTypeKind::Int };
return codegen::StackValue{
llvm::ConstantInt::get(ty, this->m_value),
std::unique_ptr<types::Type>{stack_type}
};
}
codegen::StackValue ValueReferenceExpression::codegen(codegen::Builder& builder, codegen::Scope& scope) {
auto value = scope.values.find(this->m_name);
if (value != scope.values.end()) {
if (scope.is_lvalue) {
return value->second;
}
else {
return codegen::StackValue{
builder.builder->CreateLoad(value->second.ty->codegen(builder), value->second.value),
value->second.ty
};
}
}
else {
throw new std::runtime_error("Value " + this->m_name + " not found");
}
}
codegen::StackValue BinaryOperationExpression::codegen(codegen::Builder& builder, codegen::Scope& scope) {
auto lvalued = scope.with_lvalue();
auto lhs = this->m_lhs->codegen(builder, this->m_binop == types::BinOp::Assignment ? lvalued : scope);
auto rhs = this->m_rhs->codegen(builder, scope);
switch (this->m_binop) {
case types::BinOp::Assignment:
builder.builder->CreateStore(rhs.value, lhs.value, false);
return rhs;
case types::BinOp::Add:
return codegen::StackValue{
lhs.ty->add(builder, lhs.value, rhs.value),
lhs.ty
};
default:
throw std::runtime_error("invalid binop");
}
}
void ReturnStatement::codegen(codegen::Builder& builder, codegen::Scope& scope) {
if (!builder.block)
return;
builder.builder->SetInsertPoint(builder.block);
auto value = this->m_expr->codegen(builder, scope);
builder.builder->CreateRet(value.value);
}
void ExpressionStatement::codegen(codegen::Builder& builder, codegen::Scope& scope) {
if (!builder.block)
return;
builder.builder->SetInsertPoint(builder.block);
this->m_expr->codegen(builder, scope);
}
void InitializationStatement::codegen(codegen::Builder& builder, codegen::Scope& scope) {
if (!builder.block)
return;
builder.builder->SetInsertPoint(builder.block);
auto ty = this->m_type->codegen(builder);
auto ptr = builder.builder->CreateAlloca(ty);
if (this->m_expr.has_value()) {
auto value = this->m_expr->get()->codegen(builder, scope);
builder.builder->CreateStore(value.value, ptr, false);
}
scope.values[this->m_name] = codegen::StackValue{ ptr, std::move(this->m_type) };
}
void Function::codegen(codegen::Builder& builder, codegen::Scope& scope) {
codegen::Scope inner_scope{ scope };
auto ret_ty = this->m_return_ty->codegen(builder);
std::vector<llvm::Type*> params{};
auto fn_ty = llvm::FunctionType::get(ret_ty, params, false);
auto function = llvm::Function::Create(
fn_ty,
llvm::GlobalValue::LinkageTypes::ExternalLinkage,
this->m_name,
builder.mod.get()
);
auto BB = llvm::BasicBlock::Create(*builder.context, "entry", function, nullptr);
builder.block = BB;
for (auto& statement : this->m_statements) {
statement->codegen(builder, inner_scope);
}
llvm::verifyFunction(*function);
builder.block = nullptr;
}
}
namespace types {
llvm::Type* FundamentalType::codegen(codegen::Builder& builder) {
switch (this->m_ty) {
case FundamentalTypeKind::Int:
return builder.builder->getInt32Ty();
default:
return builder.builder->getVoidTy();
}
}
}