On Mon, May 1, 2017 at 8:04 PM, Mikhail Maltsev <malts...@gmail.com> wrote:
> The first problem happens because we don't check for missing labels when
> parsing
> 'goto' statements. I.e.:
>
> __GIMPLE() void fn1() {
> if (1)
> goto
> }
>
> The fix is pretty obvious: just add a check.
> My question is: which functions should I use to produce diagnostics? The
> surrounding code uses 'c_parser_error', but this function does not handle
> locations very well (in fact, it uses input_location).
Certainly an improvement. I suppose we can do better error recovery
for cases like
if (1)
goto
else
goto bar;
but I guess this is better than nothing.
And yes, we use c_parser_error -- input_location should be ok but here
we just peek which may upset the parser. Maybe it works better
when consuming the token before issueing the error? Thus
Index: gcc/c/gimple-parser.c
===================================================================
--- gcc/c/gimple-parser.c (revision 247498)
+++ gcc/c/gimple-parser.c (working copy)
@@ -1315,8 +1315,8 @@ c_parser_gimple_if_stmt (c_parser *parse
loc = c_parser_peek_token (parser)->location;
c_parser_consume_token (parser);
label = c_parser_peek_token (parser)->value;
- t_label = lookup_label_for_goto (loc, label);
c_parser_consume_token (parser);
+ t_label = lookup_label_for_goto (loc, label);
if (! c_parser_require (parser, CPP_SEMICOLON, "expected %<;%>"))
return;
}
?
Patch is ok with or without this adjustment (and testcase adjustment).
Thanks,
Richard.
> --
> Regards,
> Mikhail Maltsev
>
> gcc/testsuite/ChangeLog:
>
> 2017-05-01 Mikhail Maltsev <malts...@gmail.com>
>
> * gcc.dg/gimplefe-error-4.c: New test.
> * gcc.dg/gimplefe-error-5.c: New test.
>
>
> gcc/c/ChangeLog:
>
> 2017-05-01 Mikhail Maltsev <malts...@gmail.com>
>
> * gimple-parser.c (c_parser_gimple_if_stmt): Check for empty labels.
>
>
