Re: [PATCH/libiberty] fix build of gdb/binutils with clang.

[Yunlian Jiang <yunlian at google dot com>]

I have the following change to make libiberty compile with _GNU_SOURCE defined
and remove the declaration of asprintf in libiberty.h if
HAVE_DECL_ASPRINTF is not
defined.

diff --git a/include/libiberty.h b/include/libiberty.h
index b33dd65..8e096a0 100644
--- a/include/libiberty.h
+++ b/include/libiberty.h
@@ -621,7 +621,7 @@ extern int pexecute (const char *, char * const *,
const char *,

 extern int pwait (int, int *, int);

-#if !HAVE_DECL_ASPRINTF
+#if defined(HAVE_DECL_ASPRINTF) && !HAVE_DECL_ASPRINTF
 /* Like sprintf but provides a pointer to malloc'd storage, which must
    be freed by the caller.  */

diff --git a/libiberty/Makefile.in b/libiberty/Makefile.in
index f06cc69..624420d 100644
--- a/libiberty/Makefile.in
+++ b/libiberty/Makefile.in
@@ -113,7 +113,8 @@ installcheck: installcheck-subdir

 INCDIR=$(srcdir)/$(MULTISRCTOP)../include

-COMPILE.c = $(CC) -c @DEFS@ $(CFLAGS) $(CPPFLAGS) -I. -I$(INCDIR)
$(HDEFINES) @ac_libiberty_warn_cflags@
+COMPILE.c = $(CC) -c @DEFS@ $(CFLAGS) $(CPPFLAGS) -I. -I$(INCDIR) \
+               $(HDEFINES) @ac_libiberty_warn_cflags@ -D_GNU_SOURCE

 # Just to make sure we don't use a built-in rule with VPATH
 .c.$(objext):
diff --git a/libiberty/configure b/libiberty/configure
index b06cab2..c6758b0 100755
--- a/libiberty/configure
+++ b/libiberty/configure
@@ -5130,6 +5130,9 @@ $as_echo "#define NEED_DECLARATION_ERRNO 1" >>confdefs.h
 fi


+$as_echo "#define _GNU_SOURCE 1" >>confdefs.h
+
+
 # Determine sizes of some types.
 # The cast to long int works around a bug in the HP C Compiler
 # version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
diff --git a/libiberty/configure.ac b/libiberty/configure.ac
index 922aa86..9f2d661 100644
--- a/libiberty/configure.ac
+++ b/libiberty/configure.ac
@@ -272,6 +272,8 @@ AC_HEADER_TIME

 libiberty_AC_DECLARE_ERRNO

+AC_DEFINE(_GNU_SOURCE)
+
 # Determine sizes of some types.
 AC_CHECK_SIZEOF([int])
 AC_CHECK_SIZEOF([long])
diff --git a/libiberty/floatformat.c b/libiberty/floatformat.c
index 789fa05..4e73a2d 100644
--- a/libiberty/floatformat.c
+++ b/libiberty/floatformat.c
@@ -19,7 +19,9 @@ along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
02110-1301, USA.  */

 /* This is needed to pick up the NAN macro on some systems.  */
+#ifndef _GNU_SOURCE
 #define _GNU_SOURCE
+#endif

 #ifdef HAVE_CONFIG_H
 #include "config.h"

On Tue, May 19, 2015 at 11:15 AM, Ian Lance Taylor <iant@google.com> wrote:
> On Tue, May 19, 2015 at 11:08 AM, Yunlian Jiang <yunlian@google.com> wrote:
>>
>> I could do that and it make the compilation of libiberty passes.
>> However, I  have some other problem when using clang to build gdb
>> because of libiberty.
>>
>> Some c file from other component may include 'libiberty.h' which contains
>> the following
>>
>> #if !HAVE_DECL_ASPRINTF
>> /* Like sprintf but provides a pointer to malloc'd storage, which must
>>    be freed by the caller.  */
>>
>> extern int asprintf (char **, const char *, ...) ATTRIBUTE_PRINTF_2;
>> #endif
>>
>> The HAVE_DECL_ASPRINTF is defined in config.h under libiberty directory.
>> If the other c file only includes libiberty.h and does not include the
>> libiberty/config.h and
>> at the same time, _GNU_SOURCE is defind, the same error happens.
>
> Probably if HAVE_DECL_ASPRINTF is not defined at all, we should not
> declare asprintf in libiberty.h.
>
> Ian