From 66f9dac5a68bd05c38744398c932dbcebbf7dde3 Mon Sep 17 00:00:00 2001
From: Sofia <sofia@teascade.net>
Date: Fri, 10 Apr 2026 18:09:55 +0300
Subject: [PATCH] Codegen if-statements

---
 src/ast.cpp     |  9 +++++----
 src/codegen.cpp | 43 +++++++++++++++++++++++++++++++++++++++++--
 src/main.cpp    | 12 +++++++++---
 3 files changed, 55 insertions(+), 9 deletions(-)

diff --git a/src/ast.cpp b/src/ast.cpp
index 2a3e88e..5cd00a3 100644
--- a/src/ast.cpp
+++ b/src/ast.cpp
@@ -29,11 +29,12 @@ namespace AST {
     }
 
     std::string IfStatement::formatted() {
-        std::stringstream out{ "if " };
-        out << this->m_condition->formatted();
-        out << "\n  then " << this->m_then->formatted();
+        std::stringstream out{ "" };
+        out << "if ";
+        out << "(" << this->m_condition->formatted() << ")";
+        out << "\n    then " << this->m_then->formatted();
         if (this->m_else.has_value())
-            out << "\n  else " << (*this->m_else)->formatted();
+            out << "\n    else " << (*this->m_else)->formatted();
         return out.str();
     }
 
diff --git a/src/codegen.cpp b/src/codegen.cpp
index 6af695c..2ed29ee 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -39,7 +39,7 @@ namespace AST {
             }
         }
         else {
-            throw new std::runtime_error("Value " + this->m_name + " not found");
+            throw std::runtime_error("Value " + this->m_name + " not found");
         }
     }
 
@@ -114,7 +114,35 @@ namespace AST {
         if (!builder.block)
             return;
 
-        // TODO
+        builder.builder->SetInsertPoint(builder.block);
+
+        auto condition = this->m_condition->codegen(builder, scope);
+
+        auto function = builder.block->getParent();
+        auto then_block = llvm::BasicBlock::Create(*builder.context, "then", function);
+
+        std::optional<llvm::BasicBlock*> else_block{};
+        if (this->m_else.has_value())
+            else_block = llvm::BasicBlock::Create(*builder.context, "else", function);
+
+        auto after_block = llvm::BasicBlock::Create(*builder.context, "after", function);
+
+        builder.builder->CreateCondBr(condition.value, then_block, else_block.value_or(after_block));
+
+        builder.block = then_block;
+        builder.builder->SetInsertPoint(then_block);
+        this->m_then->codegen(builder, scope);
+        builder.builder->CreateBr(after_block);
+
+        if (else_block.has_value()) {
+            builder.block = *else_block;
+            builder.builder->SetInsertPoint(*else_block);
+            this->m_else->get()->codegen(builder, scope);
+            builder.builder->CreateBr(after_block);
+        }
+
+        builder.block = after_block;
+        builder.builder->SetInsertPoint(after_block);
     }
 
 
@@ -123,6 +151,7 @@ namespace AST {
 
         auto ret_ty = this->m_return_ty->codegen(builder);
         std::vector<llvm::Type*> params{};
+
         for (auto& param : this->m_params) {
             params.push_back(param.second->codegen(builder));
         }
@@ -138,6 +167,16 @@ namespace AST {
         auto BB = llvm::BasicBlock::Create(*builder.context, "entry", function, nullptr);
         builder.block = BB;
 
+        int counter = 0;
+        for (auto& param : this->m_params) {
+            auto arg = function->getArg(counter++);
+            arg->setName(param.first);
+            inner_scope.values[param.first] = codegen::StackValue{
+                arg,
+                std::move(param.second),
+            };
+        }
+
         for (auto& statement : this->m_statements) {
             statement->codegen(builder, inner_scope);
         }
diff --git a/src/main.cpp b/src/main.cpp
index 93bf301..3571a97 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -79,9 +79,15 @@ int main() {
 
     codegen::Scope scope{};
 
-    for (auto& tls : statements) {
-        std::cout << tls->formatted() << std::endl;
-        tls->codegen(builder, scope);
+    try {
+        for (auto& tls : statements) {
+            std::cout << tls->formatted() << std::endl;
+            tls->codegen(builder, scope);
+        }
+    }
+    catch (std::runtime_error error) {
+        std::cerr << "FATAL: " << error.what() << std::endl;
+        return 1;
     }
 
     llvm::InitializeAllTargetInfos();