From d5853c13b7c7159951b54af0c19f1416ad346871 Mon Sep 17 00:00:00 2001
From: Markus Hauschild <hauschildm@gmx.net>
Date: Sat, 1 Jun 2013 16:41:18 +0200
Subject: [PATCH 1/2] Types!

---
 inc/AST/Type.h             |  2 ++
 src/AST/CodeGenVisitor.cpp |  1 +
 src/AST/Type.cpp           | 20 +++++++++++++++++++-
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/inc/AST/Type.h b/inc/AST/Type.h
index b0b33ee..a570f41 100644
--- a/inc/AST/Type.h
+++ b/inc/AST/Type.h
@@ -1,10 +1,12 @@
 #ifndef TYPE_H
 #define TYPE_H
 
+#include "llvm/Type.h"
 #include <string>
 
 enum class Type { BOOL, INT, STRING, VOID };
 
 std::string typeToString(Type type);
+llvm::Type* typeToLLVMType(Type type);
 
 #endif // TYPE_H
diff --git a/src/AST/CodeGenVisitor.cpp b/src/AST/CodeGenVisitor.cpp
index 3dffdce..0c466a8 100644
--- a/src/AST/CodeGenVisitor.cpp
+++ b/src/AST/CodeGenVisitor.cpp
@@ -88,6 +88,7 @@ void CodeGenVisitor::visit(FunctionCallExpression* e) {
 }
 
 void CodeGenVisitor::visit(FunctionDefinition* e) {
+	//std::vector<llvm::Type*> types;
 }
 
 void CodeGenVisitor::visit(IfStatement* e) {
diff --git a/src/AST/Type.cpp b/src/AST/Type.cpp
index b62669d..a875912 100644
--- a/src/AST/Type.cpp
+++ b/src/AST/Type.cpp
@@ -1,4 +1,6 @@
 #include "AST/Type.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/LLVMContext.h"
 
 std::string typeToString(Type type) {
 	switch (type) {
@@ -12,5 +14,21 @@ std::string typeToString(Type type) {
 		return "void";
 	default:
 		return "ERROR";
-  }
+	}
+}
+
+llvm::Type* typeToLLVMType(Type type) {
+	switch (type) {
+	case Type::BOOL:
+		return llvm::Type::getInt1Ty(llvm::getGlobalContext());
+	case Type::INT:
+		return llvm::Type::getInt32Ty(llvm::getGlobalContext());
+	case Type::STRING:
+		return llvm::Type::getInt8PtrTy(llvm::getGlobalContext());
+	case Type::VOID:
+		return llvm::Type::getVoidTy(llvm::getGlobalContext());
+	default:
+		// TODO error
+		return llvm::Type::getVoidTy(llvm::getGlobalContext());
+	}
 }

From 79339fe70ecd9a6e793836b9846c03fde1ef3a78 Mon Sep 17 00:00:00 2001
From: Markus Hauschild <hauschildm@gmx.net>
Date: Sat, 1 Jun 2013 16:53:27 +0200
Subject: [PATCH 2/2] Some FunctionDefinition stuff

---
 src/AST/CodeGenVisitor.cpp | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/src/AST/CodeGenVisitor.cpp b/src/AST/CodeGenVisitor.cpp
index 0c466a8..a376226 100644
--- a/src/AST/CodeGenVisitor.cpp
+++ b/src/AST/CodeGenVisitor.cpp
@@ -88,7 +88,38 @@ void CodeGenVisitor::visit(FunctionCallExpression* e) {
 }
 
 void CodeGenVisitor::visit(FunctionDefinition* e) {
-	//std::vector<llvm::Type*> types;
+	std::vector<llvm::Type*> argTypes;
+	auto params = e->getParams()->getParameters();
+	auto iter = params.begin();
+	auto end = params.end();
+	for (; iter != end; ++iter) {
+		Parameter& p = (*iter);
+		argTypes.push_back(typeToLLVMType(p.first));
+	}
+
+	llvm::FunctionType* ft = llvm::FunctionType::get(typeToLLVMType(e->getType()), argTypes, false);
+	llvm::Function *f = llvm::Function::Create(ft, llvm::Function::ExternalLinkage, e->getName(), module_);
+
+	// If f conflicted, there was already something named 'Name'.  If it has a body,
+	// don't allow redefinition or reextern.
+	if (f->getName() != e->getName()) {
+		f->eraseFromParent();
+		f = module_->getFunction(e->getName());
+
+		// If f already has a body, reject this.
+		if (!f->empty()) {
+			throw "redefinition of function";
+		}
+
+		// If f took a different number of args, reject.
+		if (f->arg_size() != e->getParams()->getParameters().size()) {
+			throw "redefinition of function with different # of arguments";
+		}
+	}
+
+	// TODO set arg names
+
+	value_ = f;
 }
 
 void CodeGenVisitor::visit(IfStatement* e) {