[Bug c/71858] New: Surprising suggestions for misspellings

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71858

            Bug ID: 71858
           Summary: Surprising suggestions for misspellings
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dmalcolm at gcc dot gnu.org
  Target Milestone: ---

(from email)

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$ cat /tmp/a.c
int main(int argc, char **argv)
{
  return bar();
}

$ ./xgcc -B. /tmp/a.c
/tmp/a.c: In function ‘main’:
/tmp/a.c:3:10: warning: implicit declaration of function ‘bar’; did you mean
‘carg’? [-Wimplicit-function-declaration]
   return bar();
          ^~~
          carg

Which is a bit misleading as I do not include any header file. Looks it finds a
builtin:
(gdb) p debug_tree(m_best_candidate)
 <identifier_node 0x7ffff68faaa0 carg
    symbol <function_decl 0x7ffff68ff100 carg
        type <function_type 0x7ffff68adc78 type <real_type 0x7ffff68a55e8
double>
            QI
            size <integer_cst 0x7ffff6887d98 constant 8>
            unit size <integer_cst 0x7ffff6887db0 constant 1>
            align 8 symtab 0 alias set -1 canonical type 0x7ffff68adc78
            arg-types <tree_list 0x7ffff689b960 value <complex_type
0x7ffff68a5f18 complex double>
                chain <tree_list 0x7ffff689b7a8 value <void_type 0x7ffff68a5150
void>>>>
        readonly nothrow public external built-in decl_6 QI file <built-in>
line 0 col 0
        align 8 built-in BUILT_IN_NORMAL:BUILT_IN_CARG attributes <tree_list
0x7ffff68fd488>>>

Well, I would expect it should consider __builtin_carg, but not carg.

--------------------------------------------------------------------

I'm inclined to agree; I'll see if I can filter this better.