Add static and runtime assert

ast.cpp

@@ -20,6 +20,8 @@ enum Ast_Kind: U32{
   AST_CALL_ITEM,
   AST_CALL,
 
+  AST_CONSTANT_ASSERT,
+  AST_RUNTIME_ASSERT,
   AST_SIZE_OF,
   AST_LENGTH_OF,
   AST_ALIGN_OF,
@@ -119,7 +121,8 @@ struct Ast_Binary: Ast_Expr{
 
 struct Ast_Builtin: Ast_Expr{
   Ast_Expr *expr;
-  U64 padding[3]; // For folding constants into atoms
+  Intern_String assert_message;
+  U64 padding[1]; // For folding constants into atoms
 };
 
 // Problem: We are parsing out of order, in the middle of parsing a function
@@ -197,7 +200,6 @@ struct Ast_Scope: Ast{
   Ast_Module *module;
 };
 
-
 struct Ast_Module: Ast_Scope{
   Array<Ast_File *> all_loaded_files;
 };
@@ -507,6 +509,22 @@ ast_module(Intern_String filename){
   return result;
 }
 
+function Ast_Builtin *
+ast_runtime_assert(Token *pos, Ast_Expr *expr, Intern_String message){
+  AST_NEW(Builtin, RUNTIME_ASSERT, pos, AST_EXPR);
+  result->expr = expr;
+  result->assert_message = message;
+  return result;
+}
+
+function Ast_Builtin *
+ast_constant_assert(Token *pos, Ast_Expr *expr, Intern_String message){
+  AST_NEW(Builtin, CONSTANT_ASSERT, pos, AST_EXPR);
+  result->expr = expr;
+  result->assert_message = message;
+  return result;
+}
+
 function Ast_Builtin *
 ast_sizeof(Token *pos, Ast_Expr *expr){
   AST_NEW(Builtin, SIZE_OF, pos, AST_EXPR);

ccodegen.cpp

@@ -365,6 +365,18 @@ function void
 gen_ast(Ast *ast){
   switch(ast->kind){
 
+    CASE(RUNTIME_ASSERT, Builtin){
+      if(node->assert_message.len == 0) gen("assert");
+      else                              gen("assert_msg");
+      gen("(");
+      gen_expr(node->expr);
+      if(node->assert_message.len){
+        gen(", \"%s\"", node->assert_message.str);
+      }
+      gen(");");
+      BREAK();
+    }
+
     CASE(RETURN, Return){
       gen("return");
       if(node->expr){
@@ -504,6 +516,7 @@ gen_ast(Ast *ast){
       BREAK();
     }
 
+    case AST_CONSTANT_ASSERT:
     case AST_MODULE_NAMESPACE:
     CASE(FILE_NAMESPACE, File_Namespace){unused(node); BREAK();}
 

compiler.h

@@ -164,6 +164,7 @@ Intern_String keyword_false;
 Intern_String keyword_for;
 Intern_String keyword_pass;
 Intern_String keyword_elif;
+Intern_String keyword_assert;
 Intern_String keyword_sizeof;
 Intern_String keyword_alignof;
 Intern_String keyword_lengthof;
@@ -211,6 +212,7 @@ lex_init(Allocator *token_string_arena, Allocator *map_allocator, Lexer *l){
   keyword_true = l->intern("true"_s);
   keyword_false = l->intern("false"_s);
   keyword_return = l->intern("return"_s);
+  keyword_assert = l->intern("assert"_s);
   keyword_if = l->intern("if"_s);
   keyword_elif = l->intern("elif"_s);
   keyword_pass = l->intern("pass"_s);

parsing.cpp

@@ -224,6 +224,30 @@ parse_stmt_scope(Ast_Scope *scope_defined_outside = 0){
         scope->stmts.add(ast_pass(token));
       }
 
+      else if(token_match_keyword(keyword_assert)){
+        token_expect(TK_OpenParen);
+        Ast_Expr *expr = parse_expr();
+        Intern_String message = {};
+        if(token_match(TK_Comma)){
+          Token *t = token_expect(TK_StringLit);
+          message = t->intern_val;
+        }
+        token_expect(TK_CloseParen);
+        scope->stmts.add(ast_runtime_assert(token, expr, message));
+      }
+
+      else if(token_match_pound(keyword_assert)){
+        token_expect(TK_OpenParen);
+        Ast_Expr *expr = parse_expr();
+        Intern_String message = {};
+        if(token_match(TK_Comma)){
+          Token *t = token_expect(TK_StringLit);
+          message = t->intern_val;
+        }
+        token_expect(TK_CloseParen);
+        scope->stmts.add(ast_constant_assert(token, expr, message));
+      }
+
       else if(token_match_keyword(keyword_for)){
         Ast_Scope *for_scope = begin_stmt_scope(scratch, token_get());
         Ast_Expr *init = 0;

programs/main.kl

@@ -13,8 +13,6 @@ UTF16_Result :: struct
   len    : S32
   error  : S32
 
-BINARY :: 0b1001
-
 utf8_to_utf32 :: (c: *U8, max_advance: S64): UTF32_Result
   result: UTF32_Result
   if (c[0] & 0b10000000) == 0
@@ -91,18 +89,14 @@ utf32_to_utf16 :: (codepoint: U32): UTF16_Result
 //   return result;
 // }
 
-
-
+Vec2I :: struct;; x: S32; y: S32
+Vec2  :: struct;; x: F32; y: F32
 Windows_Bitmap :: struct
   size: Vec2I
   data: *U32
   hdc: HDC
   dib: HBITMAP
 
-Vec2I :: struct;; x: S32; y: S32
-Vec2  :: struct;; x: F32; y: F32
-
-
 create_bitmap :: (size: Vec2I, bottom_up: Bool = true): Windows_Bitmap
   result: Windows_Bitmap = {size = size}
   if bottom_up == false
@@ -136,6 +130,7 @@ window_procedure :: (hwnd: HWND, msg: UINT, wparam: WPARAM, lparam: LPARAM): LRE
 main :: (argc: int, argv: **char): int
   bitmap := create_bitmap({1280, 720})
   result := utf8_to_utf32(&"A"[0], 1)
+  assert(result.out_str == 'A, "Invalid decode")
   result  = utf8_to_utf32(&"ć"[0], 2)
   result  = utf8_to_utf32(&"ó"[0], 2)
 

typechecking.cpp

@@ -443,6 +443,20 @@ resolve_stmt(Ast *ast, Ast_Type *ret){
       BREAK();
     }
 
+    CASE(RUNTIME_ASSERT, Builtin){
+      resolve_and_require_bool("Assert condition is not boolean", node->expr, AST_CAN_BE_NULL);
+      BREAK();
+    }
+
+    CASE(CONSTANT_ASSERT, Builtin){
+      Operand op = resolve_and_require_bool("Assert condition is not boolean", node->expr, AST_CAN_BE_NULL);
+      if(!op.is_const) compiler_error(node->pos, "#assert expression required to be constant");
+      if(op.bool_val == false){
+        compiler_error(node->pos, "#assert condition not met :: %.*s", (int)node->assert_message.len, node->assert_message.str);
+      }
+      BREAK();
+    }
+
     CASE(FOR, For){
       if(node->init && node->cond == 0 && node->iter == 0){
         if(!is_flag_set(node->init->flags, AST_STMT)){