[Mesa-dev] [PATCH mesa] util: improve compiler guard

[Eric Engestrom]

Glibc 2.26 has dropped xlocale.h, but the functions needed (strtod_l()
and strdof_l()) can be found in stdlib.h.
Improve the detection method to allow newer builds to still make use of
the locale-setting.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102454
Cc: Laurent Carlier <lordheavym at gmail.com>
Cc: Emil Velikov <emil.l.velikov at gmail.com>
Cc: Rob Herring <robh at kernel.org>
Signed-off-by: Eric Engestrom <eric.engestrom at imgtec.com>
---

Rob, any idea if android needs locale-setting? Emil suggested it might
always use "C" anyway.

For SCons, I added a trivial "does this function exist" check, but
I don't even know what headers it includes when checking that. There's
a chance this might break the scons build (appveyor is happy though,
fwiw).

If anyone knows how to do the same check in scons that I'm doing in
autoconf, speak up :)

---
 configure.ac      | 21 +++++++++++++++++++++
 scons/gallium.py  | 16 ++++++++++++++++
 src/util/strtod.c | 12 ++++++------
 3 files changed, 43 insertions(+), 6 deletions(-)

diff --git a/configure.ac b/configure.ac
index 53d52f6d52..f4d83e1c10 100644
--- a/configure.ac
+++ b/configure.ac
@@ -826,6 +826,27 @@ AC_CHECK_HEADER([sys/sysctl.h], [DEFINES="$DEFINES -DHAVE_SYS_SYSCTL_H"])
 AC_CHECK_FUNC([strtof], [DEFINES="$DEFINES -DHAVE_STRTOF"])
 AC_CHECK_FUNC([mkostemp], [DEFINES="$DEFINES -DHAVE_MKOSTEMP"])
 
+AC_MSG_CHECKING([whether strtod has locale support])
+AC_LINK_IFELSE([AC_LANG_SOURCE([[
+    #define _GNU_SOURCE
+    #include <stdlib.h>
+    #include <locale.h>
+    #ifdef HAVE_XLOCALE_H
+    #include <xlocale.h>
+    #endif
+    int main() {
+       locale_t loc = newlocale(LC_CTYPE_MASK, "C", NULL);
+       const char *s = "1.0";
+       char *end;
+       double d = strtod_l(s, end, loc);
+       float f = strtof_l(s, end, loc);
+       freelocale(loc);
+       return 0;
+    }]])],
+  [DEFINES="$DEFINES -DHAVE_STRTOD_L"];
+   AC_MSG_RESULT([yes]),
+   AC_MSG_RESULT([no]))
+
 dnl Check to see if dlopen is in default libraries (like Solaris, which
 dnl has it in libc), or if libdl is needed to get it.
 AC_CHECK_FUNC([dlopen], [DEFINES="$DEFINES -DHAVE_DLOPEN"],
diff --git a/scons/gallium.py b/scons/gallium.py
index c8e47a39db..1e35ef434a 100755
--- a/scons/gallium.py
+++ b/scons/gallium.py
@@ -157,6 +157,19 @@ def check_header(env, header):
     env = conf.Finish()
     return have_header
 
+def check_functions(env, functions):
+    '''Check if all of the functions exist'''
+
+    conf = SCons.Script.Configure(env)
+    have_functions = True
+
+    for function in functions:
+        if not conf.CheckFunc(function):
+            have_functions = False
+
+    env = conf.Finish()
+    return have_functions
+
 def check_prog(env, prog):
     """Check whether this program exists."""
 
@@ -339,6 +352,9 @@ def generate(env):
         if check_header(env, 'xlocale.h'):
             cppdefines += ['HAVE_XLOCALE_H']
 
+        if check_functions(env, ['strtod_l', 'strtof_l']):
+            cppdefines += ['HAVE_STRTOD_L']
+
     if platform == 'windows':
         cppdefines += [
             'WIN32',
diff --git a/src/util/strtod.c b/src/util/strtod.c
index ea7d395e2d..de695d64b4 100644
--- a/src/util/strtod.c
+++ b/src/util/strtod.c
@@ -26,13 +26,13 @@
 
 #include <stdlib.h>
 
-#ifdef _GNU_SOURCE
+#if defined(_GNU_SOURCE) && defined(HAVE_STRTOD_L)
 #include <locale.h>
 #ifdef HAVE_XLOCALE_H
 #include <xlocale.h>
+#endif
 static locale_t loc;
 #endif
-#endif
 
 #include "strtod.h"
 
@@ -40,7 +40,7 @@ static locale_t loc;
 void
 _mesa_locale_init(void)
 {
-#if defined(_GNU_SOURCE) && defined(HAVE_XLOCALE_H)
+#if defined(_GNU_SOURCE) && defined(HAVE_STRTOD_L)
    loc = newlocale(LC_CTYPE_MASK, "C", NULL);
 #endif
 }
@@ -48,7 +48,7 @@ _mesa_locale_init(void)
 void
 _mesa_locale_fini(void)
 {
-#if defined(_GNU_SOURCE) && defined(HAVE_XLOCALE_H)
+#if defined(_GNU_SOURCE) && defined(HAVE_STRTOD_L)
    freelocale(loc);
 #endif
 }
@@ -60,7 +60,7 @@ _mesa_locale_fini(void)
 double
 _mesa_strtod(const char *s, char **end)
 {
-#if defined(_GNU_SOURCE) && defined(HAVE_XLOCALE_H)
+#if defined(_GNU_SOURCE) && defined(HAVE_STRTOD_L)
    return strtod_l(s, end, loc);
 #else
    return strtod(s, end);
@@ -75,7 +75,7 @@ _mesa_strtod(const char *s, char **end)
 float
 _mesa_strtof(const char *s, char **end)
 {
-#if defined(_GNU_SOURCE) && defined(HAVE_XLOCALE_H)
+#if defined(_GNU_SOURCE) && defined(HAVE_STRTOD_L)
    return strtof_l(s, end, loc);
 #elif defined(HAVE_STRTOF)
    return strtof(s, end);
-- 
Cheers,
  Eric