On Tue, 2022-05-24 at 09:25 +0200, Jakub Jelinek via Gcc-patches wrote:
> Hi!
>
> On the following testcase (the first dg-error line) we emit a weird
> diagnostics and even fixit on pointerpointer->member
> where pointerpointer is pointer to pointer to struct and we say
> 'pointerpointer' is a pointer; did you mean to use '->'?
> The first part is indeed true, but suggesting -> when the code
> already
> does use -> is confusing.
> The following patch adjusts callers so that they tell it if it is
> from
> . parsing or from -> parsing and in the latter case suggests to
> dereference
> the left operand instead by adding (* before it and ) after it
> (before ->).
> Or would a suggestion to add [0] before -> be better?
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
[...snip implementation...]
>
> --- gcc/testsuite/gcc.dg/pr91134.c.jj 2022-05-23 20:31:11.751001817
> +0200
> +++ gcc/testsuite/gcc.dg/pr91134.c 2022-05-23 20:30:45.291268997
> +0200
> @@ -0,0 +1,13 @@
> +/* PR c/91134 */
> +
> +struct X { int member; } x;
> +
> +int
> +foo (void)
> +{
> + struct X *pointer = &x;
> + struct X **pointerpointer = &pointer;
> + int i = *pointerpointer->member; /* { dg-error
> "'pointerpointer' is a pointer to pointer; did you mean to
> dereference it before applying '->' to it\\\?" } */
> + int j = pointer.member; /* { dg-error "'pointer' is a
> pointer; did you mean to use '->'\\\?" } */
> + return i + j;
> +}
Ideally we'd have an automated check that the fix-it hint fixes the
code, but failing that, I like to have at least some DejaGnu test
coverage for fix-it hints - something like the tests in gcc.dg/fixits.c
or gcc.dg/semicolon-fixits.c, perhaps?
Dave
