Support the "malloc idiom" (#287)

self_hosted/main.jou

@@ -100,7 +100,7 @@ class Compiler:
     nfiles: int
 
     def parse_all_files(self, main_path: byte*) -> void:
-        queue: byte** = malloc(sizeof main_path)
+        queue: byte** = malloc(sizeof queue[0])
         queue[0] = main_path
         queue_len = 1
 

self_hosted/parser.jou

@@ -31,8 +31,7 @@ def parse_type(tokens: Token**) -> AstType:
     ++*tokens
 
     while (*tokens)->is_operator("*"):
-        p: AstType*
-        p = malloc(sizeof *p)
+        p: AstType* = malloc(sizeof *p)
         *p = result
         result = AstType{
             location = ((*tokens)++)->location,  # TODO: shouldn't need all the parentheses
@@ -57,8 +56,7 @@ def parse_name_type_value(tokens: Token**, expected_what_for_name: byte*) -> Ast
 
     if (*tokens)->is_operator("="):
         ++*tokens
-        p: AstExpression*
-        p = malloc(sizeof *p)
+        p: AstExpression* = malloc(sizeof *p)
         *p = parse_expression(tokens)
         result.value = p
 

self_hosted/typecheck.jou

@@ -296,8 +296,7 @@ def typecheck_expression_maybe_void(ctx: TypeContext*, expression: AstExpression
         assert(False)
         result = NULL  # never runs, but silences compiler warning
 
-    p: ExpressionTypes*
-    p = malloc(sizeof *p)
+    p: ExpressionTypes* = malloc(sizeof *p)
     *p = ExpressionTypes{
         expression = expression,
         type = result,

src/typecheck.c

@@ -1160,12 +1160,12 @@ static void typecheck_statement(TypeContext *ctx, const AstStatement *stmt)
             fail_with_error(stmt->location, "a variable named '%s' already exists", stmt->data.vardecl.name);
 
         const Type *type = type_from_ast(ctx, &stmt->data.vardecl.type);
+        add_variable(ctx, type, stmt->data.vardecl.name);
         if (stmt->data.vardecl.value) {
             typecheck_expression_with_implicit_cast(
                 ctx, stmt->data.vardecl.value, type,
                 "initial value for variable of type TO cannot be of type FROM");
         }
-        add_variable(ctx, type, stmt->data.vardecl.name);
         break;
 
     case AST_STMT_EXPRESSION_STATEMENT:

tests/should_succeed/linked_list.jou

@@ -13,8 +13,7 @@ class Node:
             putchar('\n')
 
 def prepend(list: Node**, value: byte) -> void:
-    new_first: Node*
-    new_first = malloc(sizeof *new_first)
+    new_first: Node* = malloc(sizeof *new_first)
     *new_first = Node{value = value, next = *list}
     *list = new_first