Bootstrap: Support if statement

3 files changed, 94 insertions, 1 deletions

diff --git a/src/bootstrap/codegen.pry b/src/bootstrap/codegen.pry
index 55be4fa..8b95451 100644
--- a/src/bootstrap/codegen.pry
+++ b/src/bootstrap/codegen.pry
@@ -470,7 +470,6 @@ let codegen_generate_expression_value = (c: *codegen, expression: *Node, name: *
 		/* TODO: Move to defer */
 		(*c).current_function = last_function;
 		environment_drop_scope((*c).environment);
-		
 
 		return codegen_create_variable(c, v);
 	};
@@ -634,6 +633,40 @@ let codegen_generate_function_call_statement = (c: *codegen, statement: *Node) =
 	return codegen_create_variable(c, v);
 };
 
+let codegen_generate_if_statement = (c: *codegen, statement: *NODE_IF_STATEMENT_DATA) => *void {
+	let condition_value = codegen_generate_expression_value(c, (*statement).condition, cast(*i8, null));
+	assert(condition_value != cast(*Variable, null));
+
+	let current_block = LLVMGetInsertBlock((*c).builder);
+
+	let then_block = LLVMAppendBasicBlock((*c).current_function, "then_block");
+	LLVMPositionBuilderAtEnd((*c).builder, then_block);
+
+	let i = 0;
+	while i < (*statement).statements_len {
+		let stmt = (*((*statement).statements + cast(**Node, i)));
+		let res = codegen_generate_statement(c, stmt);
+		assert(res == 0);
+		i = i + 1;
+	};
+
+	let merge_block = LLVMAppendBasicBlock((*c).current_function, "merge_block");
+	let last_instr = LLVMGetLastInstruction(LLVMGetInsertBlock((*c).builder));
+	if last_instr == cast(LLVMValueRef, null) {
+		LLVMBuildBr((*c).builder, merge_block);
+	};
+	if last_instr != cast(LLVMValueRef, null) {
+		if LLVMIsATerminatorInst(last_instr) == cast(LLVMValueRef, null) {
+			LLVMBuildBr((*c).builder, merge_block);
+		};
+	};
+	LLVMPositionBuilderAtEnd((*c).builder, current_block);
+        LLVMBuildCondBr((*c).builder, (*condition_value).value, then_block, merge_block);
+        LLVMPositionBuilderAtEnd((*c).builder, merge_block);
+
+	return null;
+};
+
 let codegen_generate_statement = (c: *codegen, statement: *Node) => i64 {
 	let stmt = *statement;
 
@@ -649,6 +682,11 @@ let codegen_generate_statement = (c: *codegen, statement: *Node) => i64 {
 		codegen_generate_function_call_statement(c, statement);
 		return 0;
 	};
+	
+	if stmt.type == NODE_IF_STATEMENT {
+		codegen_generate_if_statement(c, cast(*NODE_IF_STATEMENT_DATA, stmt.data));
+		return 0;
+	};
 
 	printf("ASSERT 3 %d\n", stmt.type);
 	assert(false);
diff --git a/src/bootstrap/llvm.pry b/src/bootstrap/llvm.pry
index 4183b99..51ab978 100644
--- a/src/bootstrap/llvm.pry
+++ b/src/bootstrap/llvm.pry
@@ -310,3 +310,8 @@ extern LLVMBuildGlobalStringPtr = (LLVMBuilderRef, *i8, *i8) => LLVMValueRef;
 extern LLVMBuildAlloca = (LLVMBuilderRef, LLVMTypeRef, *i8) => LLVMValueRef;
 extern LLVMBuildStore = (LLVMBuilderRef, LLVMValueRef, LLVMValueRef) => LLVMValueRef;
 extern LLVMBuildLoad2 = (LLVMBuilderRef, LLVMTypeRef, LLVMValueRef, *i8) => LLVMValueRef;
+extern LLVMGetLastInstruction = (LLVMBasicBlockRef) => LLVMValueRef;
+
+extern LLVMBuildBr = (LLVMBuilderRef, LLVMBasicBlockRef) => LLVMValueRef;
+extern LLVMIsATerminatorInst = (LLVMValueRef) => LLVMValueRef;
+extern LLVMBuildCondBr = (LLVMBuilderRef, LLVMValueRef, LLVMBasicBlockRef, LLVMBasicBlockRef) => LLVMValueRef;
diff --git a/src/bootstrap/parser.pry b/src/bootstrap/parser.pry
index be1ffb7..95f847b 100644
--- a/src/bootstrap/parser.pry
+++ b/src/bootstrap/parser.pry
@@ -360,6 +360,48 @@ let parser_parse_type = (p: *parser) => *Node {
 	return cast(*Node, null);
 };
 
+/* IfStatement ::= "if" Expression LBRACE Statement* RBRACE */
+let parser_parse_if_statement = (p: *parser) => *Node {
+	if parser_accept_token(p, TOKEN_IF) == cast(*token, null) {
+		return cast(*Node, null);
+	};
+
+	let expression = parser_parse_expression(p);
+	if expression == cast(*Node, null) {
+	    return cast(*Node, null);
+	};
+	
+	if parser_accept_token(p, TOKEN_LBRACE) == cast(*token, null) {
+		return cast(*Node, null);
+	};
+
+	let statements = cast(**Node, arena_alloc((*p).arena, sizeof(*Node) * 100));
+	let i = 0;
+	while true {
+		let n = parser_accept_parse(p, parser_parse_statement);
+		if n == cast(*Node, null) {
+			break;
+		};
+		(*(statements + cast(**Node, i))) = n;
+		i = i + 1;
+	};
+	
+	if parser_accept_token(p, TOKEN_RBRACE) == cast(*token, null) {
+		return cast(*Node, null);
+	};
+	
+	let dd = cast(*NODE_IF_STATEMENT_DATA, arena_alloc((*p).arena, sizeof(NODE_IF_STATEMENT_DATA)));
+	(*dd).condition = expression;
+	(*dd).statements = statements;
+	(*dd).statements_len = i;
+
+	let r = Node{};
+	r.type = NODE_IF_STATEMENT;
+	r.data = cast(*void, dd);
+
+	return create_node(p, r);
+};
+
 /* ExternDeclaration ::= "extern" IDENTIFIER EQUALS Type */
 let parser_parse_extern_declaration = (p: *parser) => *Node {
 	if parser_accept_token(p, TOKEN_EXTERN) == cast(*token, null) {
@@ -807,6 +849,14 @@ let parser_parse_statement = (p: *parser) => *Node {
 		};
 	    return retu;
 	};
+	
+	let retu = parser_accept_parse(p, parser_parse_if_statement);
+	if retu != cast(*Node, null) {
+		if parser_accept_token(p, TOKEN_SEMICOLON) == cast(*token, null) {
+		    return cast(*Node, null);
+		};
+	    return retu;
+	};
 
 	printf("None\n");