Re: [PATCH 1/3] [gdbsupport] Add gdb::{waitpid,read,write,close}

[Simon Marchi <simark@simark.ca>]

On 2024-11-22 11:46, Tom de Vries wrote:
> On 11/5/24 13:07, Tom de Vries wrote:
>> On 11/1/24 18:35, Tom Tromey wrote:
>>>>>>>> "Tom" == Tom de Vries <tdevries@suse.de> writes:
>>>
>>> Tom> +namespace gdb {
>>> Tom> +
>>> Tom> +extern "C" {
>>>
>>> I didn't even know this was valid ... but is it really needed?
>>> It seems wrong.
>>>
>>
>> It seemed to work:
>> ...
>> $ cat test.c
>> namespace gdb {
>>
>>    extern "C" {
>>      int foo (void) { return 1; };
>>    }
>> }
>>
>> $ cat test2.c
>> namespace gdb {
>>    extern "C" {
>>      int foo (void);
>>    }
>> }
>>
>> int
>> main (void)
>> {
>>    return gdb::foo ();
>> }
>> $ g++ test.c test2.c
>> ...
>> but the linkage symbol is plain foo:
>> ...
>> $ nm ./a.out  | grep foo
>> 00000000004004c7 T foo
>> ...
>>
>> So, you're right, this is wrong.
>>
>> I seem to have ended up with gdb_waitpid instead of gdb::waitpid in v2, similar to gdb_select, but thinking about it now I slightly prefer gdb::waitpid.  I suppose it doesn't matter that much.
>>
> 
> When looking at this again today, it bugged me enough rewrite v2 in the gdb::waitpid style.  Committed after retesting.

When building for mingw-w64, I see this, which seems related:

      CXX    cli/cli-cmds.o
    In file included from /home/simark/src/binutils-gdb/gdb/cli/cli-cmds.c:58:
    /home/simark/src/binutils-gdb/gdb/../gdbsupport/eintr.h: In function ‘pid_t gdb::waitpid(pid_t, int*, int)’:
    /home/simark/src/binutils-gdb/gdb/../gdbsupport/eintr.h:77:35: error: ‘::waitpid’ has not been declared; did you mean ‘gdb::waitpid’?
       77 |   return gdb::handle_eintr (-1, ::waitpid, pid, wstatus, options);
          |                                   ^~~~~~~
          |                                   gdb::waitpid
    /home/simark/src/binutils-gdb/gdb/../gdbsupport/eintr.h:75:1: note: ‘gdb::waitpid’ declared here
       75 | waitpid (pid_t pid, int *wstatus, int options)
          | ^~~~~~~

Note that to get to it, you have to step past this other build error in
gdbserver (by doing `make all-gdb` for instance):

  https://inbox.sourceware.org/gdb-patches/75926446-4c8a-40ee-8ed8-ab55f38e1520@simark.ca/T/#m194744b18419e37dfb4ec82c8e0ce73fb017ba17

Simon