[Mesa-dev] [PATCH] util: port _mesa_strto[df] to C

[Ian Romanick]

On 03/15/2015 12:05 PM, Erik Faye-Lund wrote:
> _mesa_strtod and _mesa_strtof are only used from the GLSL compiler,

It's also used in the ARB_vertex_program / ARB_fragment_program
assembler in src/prog.

> so the locale doesn't need to be initialized before the first context
> gets initialized. So let's use explicit initialization from the
> one-time init code instead of depending on a C++ compiler to initialize
> at image-load time.

This is fairly close to the way Chia-I originally had it:

http://lists.freedesktop.org/archives/mesa-dev/2014-April/058215.html

Some discussion of alternate methods started:

http://lists.freedesktop.org/archives/mesa-dev/2014-May/058861.html

I'm a little concerned that having the initialization in Mesa and the
function accessible to both Mesa and Gallium that we may set ourselves
up for problems later.

It also occurs to me that the neither the old code nor the new code ever
call freelocale.  I think that's easier to fix with the static object
method (using a destructor).

I guess I'm kind of ambivalent about the change.

> Signed-off-by: Erik Faye-Lund <kusmabite at gmail.com>
> ---
> 
> Because of the recent discussion on libc++ and Mesa, I thought I'd
> have a look into what parts of mesa depended on libc++, and I spotted
> this file.
> 
> In this case, it was rather trivial to port the code to plain C, making
> it dead obvious that it doesn't depend on libc++. I'm not proposing all
> C++ gets this treatment, but in this case it seems like a pretty
> straight-forward way to make it obvious that this code does not depend
> on libc++.
> 
>  src/mesa/main/context.c           |  3 +++
>  src/util/Makefile.sources         |  2 +-
>  src/util/{strtod.cpp => strtod.c} | 14 ++++++++------
>  src/util/strtod.h                 |  3 +++
>  4 files changed, 15 insertions(+), 7 deletions(-)
>  rename src/util/{strtod.cpp => strtod.c} (89%)
> 
> diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
> index 22c2341..de6a016 100644
> --- a/src/mesa/main/context.c
> +++ b/src/mesa/main/context.c
> @@ -119,6 +119,7 @@
>  #include "shared.h"
>  #include "shaderobj.h"
>  #include "util/simple_list.h"
> +#include "util/strtod.h"
>  #include "state.h"
>  #include "stencil.h"
>  #include "texcompress_s3tc.h"
> @@ -398,6 +399,8 @@ one_time_init( struct gl_context *ctx )
>        assert( sizeof(GLint) == 4 );
>        assert( sizeof(GLuint) == 4 );
>  
> +      _mesa_locale_init();
> +
>        _mesa_one_time_init_extension_overrides();
>  
>        _mesa_get_cpu_features();
> diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources
> index 560ea83..f930790 100644
> --- a/src/util/Makefile.sources
> +++ b/src/util/Makefile.sources
> @@ -17,7 +17,7 @@ MESA_UTIL_FILES :=	\
>  	set.c \
>  	set.h \
>  	simple_list.h \
> -	strtod.cpp \
> +	strtod.c \
>  	strtod.h \
>  	texcompress_rgtc_tmp.h \
>  	u_atomic.h
> diff --git a/src/util/strtod.cpp b/src/util/strtod.c
> similarity index 89%
> rename from src/util/strtod.cpp
> rename to src/util/strtod.c
> index 2b4dd98..a4a60e0 100644
> --- a/src/util/strtod.cpp
> +++ b/src/util/strtod.c
> @@ -30,18 +30,20 @@
>  #include <locale.h>
>  #ifdef HAVE_XLOCALE_H
>  #include <xlocale.h>
> +static locale_t loc;
>  #endif
>  #endif
>  
>  #include "strtod.h"
>  
>  
> +void
> +_mesa_locale_init(void)
> +{
>  #if defined(_GNU_SOURCE) && defined(HAVE_XLOCALE_H)
> -static struct locale_initializer {
> -   locale_initializer() { loc = newlocale(LC_CTYPE_MASK, "C", NULL); }
> -   locale_t loc;
> -} loc_init;
> +   loc = newlocale(LC_CTYPE_MASK, "C", NULL);
>  #endif
> +}
>  
>  /**
>   * Wrapper around strtod which uses the "C" locale so the decimal
> @@ -51,7 +53,7 @@ double
>  _mesa_strtod(const char *s, char **end)
>  {
>  #if defined(_GNU_SOURCE) && defined(HAVE_XLOCALE_H)
> -   return strtod_l(s, end, loc_init.loc);
> +   return strtod_l(s, end, loc);
>  #else
>     return strtod(s, end);
>  #endif
> @@ -66,7 +68,7 @@ float
>  _mesa_strtof(const char *s, char **end)
>  {
>  #if defined(_GNU_SOURCE) && defined(HAVE_XLOCALE_H)
> -   return strtof_l(s, end, loc_init.loc);
> +   return strtof_l(s, end, loc);
>  #elif defined(HAVE_STRTOF)
>     return strtof(s, end);
>  #else
> diff --git a/src/util/strtod.h b/src/util/strtod.h
> index 02c25dd..b7e2beb 100644
> --- a/src/util/strtod.h
> +++ b/src/util/strtod.h
> @@ -31,6 +31,9 @@
>  extern "C" {
>  #endif
>  
> +extern void
> +_mesa_locale_init(void);
> +
>  extern double
>  _mesa_strtod(const char *s, char **end);
>