From 8c4f7e141af7c49383c156fdc354304532fc6b2e Mon Sep 17 00:00:00 2001
From: greg <greg.shuflin@protonmail.com>
Date: Tue, 10 Jan 2017 03:33:02 -0800
Subject: [PATCH] Compiling if statements like half done

---
 src/compilation.rs | 34 +++++++++++++++++++++++++++++-----
 src/llvm_wrap.rs   | 19 +++++++++++++++++++
 2 files changed, 48 insertions(+), 5 deletions(-)

diff --git a/src/compilation.rs b/src/compilation.rs
index d742eae..c23b939 100644
--- a/src/compilation.rs
+++ b/src/compilation.rs
@@ -128,9 +128,9 @@ impl CodeGen for Expression {
 
         let int_type = LLVMWrap::Int64TypeInContext(data.context);
 
-        match self {
-            &Variable(ref name) => *data.variables.get(&**name).unwrap(),
-            &BinExp(ref op, ref left, ref right) if **op == "=" => {
+        match *self {
+            Variable(ref name) => *data.variables.get(&**name).unwrap(),
+            BinExp(ref op, ref left, ref right) if **op == "=" => {
                 if let Variable(ref name) = **left {
                     let new_value = right.codegen(data);
                     data.variables.insert((**name).clone(), new_value);
@@ -139,7 +139,7 @@ impl CodeGen for Expression {
                     panic!("Bad variable assignment")
                 }
             }
-            &BinExp(ref op, ref left, ref right) => {
+            BinExp(ref op, ref left, ref right) => {
                 let lhs = left.codegen(data);
                 let rhs = right.codegen(data);
                 let generator = match op.as_ref().as_ref() {
@@ -153,11 +153,35 @@ impl CodeGen for Expression {
 
                 generator(data.builder, lhs, rhs, "temp")
             }
-            &Number(ref n) => {
+            Number(ref n) => {
                 let native_val = *n as u64;
                 let int_value: LLVMValueRef = LLVMWrap::ConstInt(int_type, native_val, false);
                 int_value
             }
+            Conditional(ref test, ref then_block, ref else_block) => {
+                let condition_value = test.codegen(data);
+                let zero = LLVMWrap::ConstInt(int_type, 0, false);
+                let is_nonzero = LLVMWrap::BuildICmp(data.builder,
+                                                     llvm_sys::LLVMIntPredicate::LLVMIntNE,
+                                                     condition_value,
+                                                     zero,
+                                                     "is_nonzero");
+
+                let func = 4;
+                let then_block = LLVMWrap::AppendBasicBlockInContext(data.context,
+                                                                     func,
+                                                                     "entry");
+                let else_block = LLVMWrap::AppendBasicBlockInContext(data.context,
+                                                                     func,
+                                                                     "entry");
+                let merge_block = LLVMWrap::AppendBasicBlockInContext(data.context,
+                                                                      func,
+                                                                      "entry");
+                //LLVMWrap::BuildCondBr(data.builder, is_nonzero, g
+
+                unimplemented!()
+
+            }
             _ => unimplemented!(),
         }
     }
diff --git a/src/llvm_wrap.rs b/src/llvm_wrap.rs
index f22396a..ec15f21 100644
--- a/src/llvm_wrap.rs
+++ b/src/llvm_wrap.rs
@@ -2,6 +2,7 @@
 #![allow(dead_code)]
 extern crate llvm_sys;
 
+use self::llvm_sys::LLVMIntPredicate;
 use self::llvm_sys::prelude::*;
 use self::llvm_sys::core;
 use std::ptr;
@@ -132,6 +133,24 @@ pub fn BuildSRem(builder: LLVMBuilderRef,
     unsafe { core::LLVMBuildSRem(builder, lhs, rhs, name.as_ptr()) }
 }
 
+pub fn BuildCondBr(builder: LLVMBuilderRef,
+                   if_expr: LLVMValueRef,
+                   then_expr: LLVMBasicBlockRef,
+                   else_expr: LLVMBasicBlockRef) -> LLVMValueRef {
+
+
+    unsafe { core::LLVMBuildCondBr(builder, if_expr, then_expr, else_expr) }
+}
+
+pub fn BuildICmp(builder: LLVMBuilderRef,
+                 op: LLVMIntPredicate,
+                 lhs: LLVMValueRef,
+                 rhs: LLVMValueRef,
+                 name: &str) -> LLVMValueRef {
+    let name = CString::new(name).unwrap();
+    unsafe { core::LLVMBuildICmp(builder, op, lhs, rhs, name.as_ptr()) }
+}
+
 pub fn PrintModuleToFile(module: LLVMModuleRef, filename: &str) -> LLVMBool {
     let out_file = CString::new(filename).unwrap();
     unsafe { core::LLVMPrintModuleToFile(module, out_file.as_ptr(), ptr::null_mut()) }