From becdac1f7f0bfd5f0bf0559cb90cd3b535b03c67 Mon Sep 17 00:00:00 2001
From: Stefano Sanfilippo <a.little.coder@gmail.com>
Date: Thu, 5 Mar 2015 22:27:14 +0100
Subject: [PATCH] Bitcode emitter for expressions and returns, more things in
 place.

---
 BitcodeEmitter.cpp | 128 +++++++++++++++++++++++++++++++++++++++++----
 BitcodeEmitter.hpp |  10 +++-
 2 files changed, 127 insertions(+), 11 deletions(-)

diff --git a/BitcodeEmitter.cpp b/BitcodeEmitter.cpp
index f0d128a..e7078c9 100644
--- a/BitcodeEmitter.cpp
+++ b/BitcodeEmitter.cpp
@@ -18,14 +18,28 @@
  */
 
 #include "BitcodeEmitter.hpp"
+#include "Scope.hpp"
 #include "Nodes.hpp"
 
+#include <llvm/Analysis/Verifier.h>
+#include <llvm/IR/DerivedTypes.h>
+#include <llvm/IR/IRBuilder.h>
+#include <llvm/IR/LLVMContext.h>
+#include <llvm/IR/Module.h>
+
+
 using namespace monicelli;
+using llvm::getGlobalContext;
 
 struct BitcodeEmitter::Private {
+    llvm::Value *expval = nullptr;
+    llvm::Module *module = nullptr;
+
+    llvm::IRBuilder<> builder = llvm::IRBuilder<>(getGlobalContext());
+    Scope<Id const*, llvm::Value*> scope;
 };
 
-BitcodeEmitter::BitcodeEmitter() {
+BitcodeEmitter::BitcodeEmitter(llvm::Module *module): module(module) {
     d = new Private;
 }
 
@@ -34,6 +48,12 @@ BitcodeEmitter::~BitcodeEmitter() {
 }
 
 void BitcodeEmitter::emit(Return const& node) {
+    if (node.getExpression()) {
+        node.getExpression()->emit(this);
+        d->builder.CreateRet(d->expval);
+    } else {
+        d->builder.CreateRetVoid();
+    }
 }
 
 void BitcodeEmitter::emit(Loop const& node) {
@@ -60,36 +80,126 @@ void BitcodeEmitter::emit(Assert const& node) {
 void BitcodeEmitter::emit(FunctionCall const& node) {
 }
 
-void BitcodeEmitter::emit(BranchCase const& node) {
-}
-
 void BitcodeEmitter::emit(Branch const& node) {
 }
 
 void BitcodeEmitter::emit(Main const& node) {
+    d->scope.enter();
+    for (Statement const* statement: node.getBody()) {
+        statement->emit(this);
+    }
+    d->scope.leave();
 }
 
 void BitcodeEmitter::emit(Function const& node) {
 }
 
-void BitcodeEmitter::emit(Module const& node) {
-}
+void BitcodeEmitter::emit(Module const& node) {}
 
-void BitcodeEmitter::emit(Program const& node) {
+void BitcodeEmitter::emit(Program const& program) {
+    if (program.getMain()) {
+        program.getMain()->emit(this);
+    }
+
+    for (Function const* function: program.getFunctions()) {
+        function->emit(this);
+    }
+
+    // TODO modules
 }
 
 void BitcodeEmitter::emit(Id const& node) {
+    auto value = d->scope.lookup(&node);
+
+    if (!value) {
+        // TODO errore
+    }
+
+    d->expval = *value;
 }
 
 void BitcodeEmitter::emit(Integer const& node) {
+    d->expval = llvm::ConstantInt::get(
+        getGlobalContext(), llvm::APInt(64, node.getValue(), true)
+    );
 }
 
 void BitcodeEmitter::emit(Float const& node) {
+    d->expval = llvm::ConstantFP::get(
+        getGlobalContext(), llvm::APFloat(node.getValue())
+    );
 }
 
-void BitcodeEmitter::emit(BinaryExpression const& node) {
+static inline
+bool isFP(llvm::Value const* var) {
+    llvm::Type *type = var->getType();
+    return type->isFloatTy() || type->isDoubleTy();
 }
 
-void BitcodeEmitter::emit(BinarySemiExpression const& node) {
+#define HANDLE(intop, fpop) \
+    if (fp) { \
+        d->expval = d->builder.Create##fpop(left, right); \
+    } else { \
+        d->expval = d->builder.Create##intop(left, right); \
+    }
+
+#define HANDLE_INT_ONLY(op) \
+    if (fp) { \
+        d->expval = nullptr; \
+    } else { \
+        d->expval = d->builder.Create##op(left, right); \
+    }
+
+
+// TODO Handle automatic casts
+void BitcodeEmitter::emit(BinaryExpression const& expression) {
+    expression.getLeft().emit(this);
+    llvm::Value *left = d->expval;
+
+    expression.getRight().emit(this);
+    llvm::Value *right = d->expval;
+
+    bool fp = isFP(left) || isFP(right);
+
+    // TODO left->getType() != right->getType()
+
+    switch (expression.getOperator()) {
+        case Operator::PLUS:
+            HANDLE(Add, FAdd)
+            break;
+        case Operator::MINUS:
+            HANDLE(Sub, FSub)
+            break;
+        case Operator::TIMES:
+            HANDLE(Mul, FMul)
+            break;
+        case Operator::DIV:
+            HANDLE(SDiv, FDiv)
+            break;
+        case Operator::SHL:
+            HANDLE_INT_ONLY(Shl);
+            break;
+        case Operator::SHR:
+            HANDLE_INT_ONLY(LShr);
+            break;
+        case Operator::LT:
+            HANDLE(ICmpULT, FCmpULT)
+            break;
+        case Operator::GT:
+            HANDLE(ICmpUGT, FCmpUGT)
+            break;
+        case Operator::GTE:
+            HANDLE(ICmpUGE, FCmpUGE)
+            break;
+        case Operator::LTE:
+            HANDLE(ICmpULE, FCmpULE)
+            break;
+        case Operator::EQ:
+            HANDLE(ICmpEQ, FCmpOEQ)
+            break;
+    }
 }
 
+#undef HANDLE
+#undef HANDLE_INT_ONLY
+
diff --git a/BitcodeEmitter.hpp b/BitcodeEmitter.hpp
index e96067c..9ab6899 100644
--- a/BitcodeEmitter.hpp
+++ b/BitcodeEmitter.hpp
@@ -22,11 +22,15 @@
 
 #include "Emitter.hpp"
 
+namespace llvm {
+    class Module;
+}
+
 namespace monicelli {
 
 class BitcodeEmitter: public Emitter {
 public:
-    BitcodeEmitter();
+    BitcodeEmitter(llvm::Module *module);
     BitcodeEmitter(BitcodeEmitter &) = delete;
     virtual ~BitcodeEmitter();
 
@@ -54,7 +58,9 @@ public:
 
 private:
     struct Private;
-    Private const* d;
+
+    llvm::Module *module;
+    Private *d;
 };
 
 }