[Bug c/103210] New: "warning: braces around scalar initializer" should have a warning flag controlling it [-Wmany-braces-around-scalar-init]

[Bug c/103210] New: "warning: braces around scalar initializer" should have a warning flag controlling it [-Wmany-braces-around-scalar-init]

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103210

            Bug ID: 103210
           Summary: "warning: braces around scalar initializer" should
                    have a warning flag controlling it
                    [-Wmany-braces-around-scalar-init]
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: egallager at gcc dot gnu.org
                CC: dmalcolm at gcc dot gnu.org, dodji at gcc dot gnu.org,
                    mpolacek at gcc dot gnu.org
            Blocks: 44209
  Target Milestone: ---

Example from libopcodes:

xstormy16-opc.c:1013:5: warning: braces around scalar initializer
 1013 |     { 0|A(ALIAS), { { { (1<<MACH_BASE), 0 } } } }
      |     ^

git grep says it comes from line 8851 in gcc/c/c-typeck.c:
https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/c/c-typeck.c;h=782414f8c8cb66b155a3cd7432706caed8828b32;hb=HEAD#l8851

...which has:

warning_init (input_location, 0, "braces around scalar initializer");

If warning_init() works like the other diagnostic functions, I'm assuming the
"0" for the second argument just needs to be changed to a warning flag?

This is an instance of bug 44209. I'm cc-ing the diagnostics maintainers, and
Marek Polacek, since git blame says he was the last to touch the line in
question.

As for a warning name, in bug 95559 it was mentioned that apparently clang
calls this -Wmany-braces-around-scalar-init, so maybe use that?


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44209
[Bug 44209] [meta-bug] Some warnings are not linked to diagnostics options

[Bug c/103210] "warning: braces around scalar initializer" should have a warning flag controlling it [-Wmany-braces-around-scalar-init]

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103210

--- Comment #1 from Eric Gallager <egallager at gcc dot gnu.org> ---
Note that this also applies to the related "excess elements in scalar
initializer" pedwarn at lines 10574-10575 in the same file:

https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/c/c-typeck.c;h=782414f8c8cb66b155a3cd7432706caed8828b32;hb=HEAD#l10575

[Bug c/103210] "warning: braces around scalar initializer" should have a warning flag controlling it [-Wmany-braces-around-scalar-init]

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103210

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Eric Gallager from comment #0)
> As for a warning name, in bug 95559 it was mentioned that apparently clang
> calls this -Wmany-braces-around-scalar-init, so maybe use that?

Just "many" doesn't make any sense for "too many" IMHO. They mean different
things. The clang name seems poor.

[Bug c/103210] "warning: braces around scalar initializer" should have a warning flag controlling it [-Wmany-braces-around-scalar-init]

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103210

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
And GCC already has a distinct "too many braces around scalar initializer"
diagnostic (an error) for the cases covered by that Clang option. I think this
is a different case (although without a proper testcase I'm not sure exactly
what kind of initializer causes the warning).

[Bug c/103210] "warning: braces around scalar initializer" should have a warning flag controlling it [-Wmany-braces-around-scalar-init]

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103210

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-11-12

[Bug c/103210] "warning: braces around scalar initializer" should have a warning flag controlling it [-Wmany-braces-around-scalar-init]

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103210

--- Comment #4 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #3)
> And GCC already has a distinct "too many braces around scalar initializer"
> diagnostic (an error) for the cases covered by that Clang option. I think
> this is a different case (although without a proper testcase I'm not sure
> exactly what kind of initializer causes the warning).

I think that that one is for the C++ front-end, while this one is for the plain
C front-end.

[Bug c/103210] "warning: braces around scalar initializer" should have a warning flag controlling it [-Wmany-braces-around-scalar-init]

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103210

--- Comment #5 from Eric Gallager <egallager at gcc dot gnu.org> ---
Downstream version of this issue:
https://github.com/cooljeanius/apple-gdb-1824/issues/9