[Bug debug/67192] Backward-goto in loop can get wrong line number

["dmalcolm at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67192

--- Comment #5 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
(In reply to David Malcolm from comment #3)
> Created attachment 36203 [details]
> Patch
> 
> The issue seems to be in here in c_parser_for_statement:
> 
>   warn_for_misleading_indentation (for_loc, body_loc,
> 				   c_parser_peek_token (parser)->location,
> 				   c_parser_peek_token (parser)->type,
> 				   "for");
> 
> where the calls to c_parser_peek_token can lead to input_location being
> changed.
> 
> The attached patch (barely tested) restores the previous location for the
> "goto" by saving and restoring input_location.

The given patch was on top of r223098
(e5f01cbafce70120afe8f73df099dcc2796adcd7), but doesn't apply to trunk; r226477
(9255be07ea1ac0e2f2991aa11cfc892474add3b2) changed the internal API for this,
so the save/restore of input_location would need updating for this.
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From: "cubbi at cubbi dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/67259] New: list-initialization of a reference fails to initialize char array from string literal
Date: Tue, 18 Aug 2015 16:22:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?idg259

            Bug ID: 67259
           Summary: list-initialization of a reference fails to initialize
                    char array from string literal
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: cubbi at cubbi dot org
  Target Milestone: ---

The following is accepted by clang, intel, and msvc, but fails to compile with
gcc (HEAD 6.0.0 20150817)

struct agg { char str[20]; };
int main() {
    const agg& r {"foo"};
}

with the following diagnostic:

prog.cc: In function 'int main()':
prog.cc:3:24: error: invalid initialization of reference of type 'const agg&'
from expression of type '<brace-enclosed initializer list>'
     const agg& r {"foo"};
                        ^
prog.cc:3:16: warning: unused variable 'r' [-Wunused-variable]
     const agg& r {"foo"};
                ^
(this also prevents agg x; x = { "foo" };)

it appears to be one of the consequences of the changes to list initialization
recently made by http://open-std.org/JTC1/SC22/WG21/docs/cwg_defects.html#1467