Better error for int a[4] = .... #1518

releasenotes.md

@@ -5,6 +5,7 @@
 ### Changes / improvements
 - Const vector -> const slice implicit conversion.
 - Slicing arrays, slices and bytes at compile time #1466.
+- Better error for `int a[4] = ...`. #1518
 
 ### Fixes
 - `Unsupported int[*] $x = { 1, 2, 3, 4 }` #1489.

src/compiler/parse_global.c

@@ -1158,11 +1158,21 @@ static inline Decl *parse_global_declaration(ParseContext *c)
  }
  if (!parse_decl_initializer(c, decl)) return poisoned_decl;
  }
- else if (!decl->attributes && tok_is(c, TOKEN_LPAREN) && !threadlocal)
+ else if (!decl->attributes)
  {
- // Guess we forgot `fn`? -> improve error reporting.
- print_error_at(type->span, "This looks like the beginning of a function declaration but it's missing the initial `fn`. Did you forget it?");
- return poisoned_decl;
+ if (tok_is(c, TOKEN_LPAREN) && !threadlocal)
+ {
+ // Guess we forgot `fn`? -> improve error reporting.
+ print_error_at(type->span, "This looks like the beginning of a function declaration but it's missing the initial `fn`. Did you forget it?");
+ return poisoned_decl;
+ }
+ else if (tok_is(c, TOKEN_LBRACKET))
+ {
+ // Maybe we were doing int foo[4] = ...
+ PRINT_ERROR_HERE("This looks like a declaration of the format 'int foo[4]' "
+ "which is c-style array declaration. In C3, you need to use something like 'int[4] foo' instead.");
+ return poisoned_decl;
+ }
  }
  CONSUME_EOS_OR_RET(poisoned_decl);
  Attr **attributes = decl->attributes;

src/compiler/parse_stmt.c

@@ -16,13 +16,32 @@ static Ast *parse_decl_stmt_after_type(ParseContext *c, TypeInfo *type)
  ast->ast_kind = AST_DECLARE_STMT;
  ASSIGN_DECL_OR_RET(ast->declare_stmt, parse_local_decl_after_type(c, type), poisoned_ast);
  Decl *decl = ast->declare_stmt;
- if (tok_is(c, TOKEN_LBRACE) && decl->var.init_expr && decl->var.init_expr->expr_kind == EXPR_IDENTIFIER)
+ switch (c->tok)
  {
- print_error_at(decl->var.init_expr->span, "An identifier would not usually be followed by a '{'. Did you intend write the name of a type here?");
- return poisoned_ast;
+ case TOKEN_LBRACE:
+ if (decl->var.init_expr && decl->var.init_expr->expr_kind == EXPR_IDENTIFIER)
+ {
+ print_error_at(decl->var.init_expr->span,
+ "An identifier would not usually be followed by a '{'. Did you intend write the name of a type here?");
+ return poisoned_ast;
+ }
+ break;
+ case TOKEN_LBRACKET:
+ if (!decl->var.init_expr)
+ {
+ SourceSpan span = extend_span_with_token(type->span, c->span);
+ print_error_at(span, "This looks like the beginning of a declaration with the format 'int %s[4]' "
+ "which is a c-style array declaration. In C3, you need to use something like 'int[4] %s' instead.",
+ decl->name, decl->name);
+ return poisoned_ast;
+ }
+ break;
+ case TOKEN_EOS:
+ return ast;
+ default:
+ break;
  }
 
- if (tok_is(c, TOKEN_EOS)) return ast;
  if (decl->attributes || decl->var.init_expr)
  {
  if (tok_is(c, TOKEN_COMMA) && peek(c) == TOKEN_IDENT)

test/unit/stdlib/crypto/rc4.c3

@@ -8,9 +8,9 @@ fn void! rc_crypt() @test
  char[200] x;
  String text = "The quick brown fox jumps over the lazy dog.";
  rc.crypt(text, &x);
- char[*] res = x"2ac2fecdd8fbb84638e3a4
+ char[*] res = x`2ac2fecdd8fbb84638e3a4
  820eb205cc8e29c28b9d5d
  6b2ef974f311964971c90e
- 8b9ca16467ef2dc6fc3520";
+ 8b9ca16467ef2dc6fc3520`;
  assert(res[:text.len] == x[:text.len]);
 }