Re: [RFC 1/6 -V2] Fix display of tabulation character for mingw hosts.

[Keith Seitz <keiths@redhat.com>]

On 10/01/2013 01:02 AM, Pierre Muller wrote:
>> -----Message d'origine-----
>> De : gdb-patches-owner@sourceware.org [mailto:gdb-patches-
>> owner@sourceware.org] De la part de Keith Seitz
>> Envoyé : mardi 1 octobre 2013 03:19
>> À : Pierre Muller
>> Cc : 'gdb-patches'
>> Objet : Re: [RFC 1/6] Fix display of tabulation character for mingw hosts.
>>
>    Yes, I must confess that I broke more coding style rules
> than I usually do here, sorry about that...

It happens to all of us; don't worry about it.

>> Does this fix the output of many tests in the test suite already? If
>> not, it would be really, really nice to have a test to check (and
>> demonstrate) this quirk.
>
> It does fix 2 failures inside printcmds.exp
>
> 288-p ctable1[9]
> 289:$50 = 9 '\t'
> 290-(gdb) PASS: gdb.base/printcmds.exp: p ctable1[9]
> 291-p ctable1[10]
> 292-$51 = 10 '\n'
> --
> 1869-$560 = (unsigned char *) <ctable1+1> "\001\002\003\004\005\006\a\b"...
> 1870-(gdb) PASS: gdb.base/printcmds.exp: p &ctable1[1]
> 1871-p &ctable1[1*8]
> 1872:$561 = (unsigned char *) <ctable1+8> "\b\t\n\v\f\r\016\017"...
> 1873-(gdb) PASS: gdb.base/printcmds.exp: p &ctable1[1*8]
> 1874-p &ctable1[2*8]
> 1875-$562 = (unsigned char *) <ctable1+16>
> "\020\021\022\023\024\025\026\027"...
>
> Is this enough?

Yes, I just wanted to make sure that if this regressed, it would be 
caught by some test. I am still having difficulties running tests on MinGW.

>    Here is a new patch version.
> To avoid the very complicated preprocessor checks that decides if we
> use wide chars inside gdb_wchar.h, I added a new macro
> HAVE_MINGW_GDB_ISWPRINT.
>    While the idea seems good to me, I am unsure about the choice
> of this macro name, are there similar examples already inside the code?

To be honest, I'm not a really big fan of putting platform-specific 
knowledge into the source code without abstraction, but in this case, 
the alternative of creating, e.g., a nm.h file for this and replicating 
all the #if ... logic in gdb_wchar.h is even less appealing to me. 
[There is some precedent for this approach, too.]

I would just drop the "MINGW" part of the name. There's always the 
possibility that some other platform might require a similar workaround. 
Perhaps a maintainer will chime in here with a more 
elegant/attractive/appropriate approach.

> ChangeLog entry:
>
> 2013-10-01  Pierre Muller <muller@sourceware.org>
>
>   	Fix display of tabulation character for MinGW hosts.
>   	* gdb_wchar.h (gdb_iswprint): Declare as external function
>   	if __MINGW32__ macro is set.

I think you can simply use: "Declare as external function on MinGW."

> 	(HAVE_MINGW_GDB_ISWPRINT): New macro, declared only for
>   	MinGW hosts using wide characters.
>   	* mingw-hdep.c (gdb_iswprint): New function.
> 	Implemented only if HAVE_MINGW_GDB_ISWPRINT macro is defined.

The custom IIRC is to use:
	* mingw-hdep.c (gdb_iswprint) [HVAE_MINGW_ISWPRINT]: New function.

I think it is time for a maintainer to review this.

Keith