Re: [PATCH 3/7] Include alloca.h unconditionally

[Yao Qi <yao at codesourcery dot com>]

Pedro Alves <palves@redhat.com> writes:

>> -#ifdef HAVE_ALLOCA_H
>> -#include <alloca.h>
>> -#endif
>>  /* On some systems such as MinGW, alloca is declared in malloc.h
>>     (there is no alloca.h).  */
>>  #if HAVE_MALLOC_H
>
> We should remove the malloc.h includes too then, and the check
> for malloc.h in configure.ac.  It's only included for alloca.

That is a good point.  The patch below is to do so.

-- 
Yao (éå)

Subject: [PATCH] Include alloca.h unconditionally

Since gnulib alloca module was imported, we can include alloca.h in
both gdb and gdbserver unconditionally, so this patch adds inclusion
of alloca.h in common-defs.h.  This patch also removes AC_FUNC_ALLOCA
in configure.ac because we don't need to check alloca any more.

This patch below is removed in fact.

  [RFA/commit] include alloca.h if available.
  https://www.sourceware.org/ml/gdb-patches/2010-08/msg00566.html

Since alloca.h is from gnulib now, we don't have to check malloc.h in
configure and include malloc.h in code.  This patch also removes them
too.

gdb:

2014-11-21  Yao Qi  <yao@codesourcery.com>

	* common/common-defs.h: Include alloca.h
	* configure.ac: Don't invoke AC_FUNC_ALLOCA.
	* configure: Re-generated.
	* defs.h: Remove code handling alloca.
	* utils.c (gdb_realpath): Don't check HAVE_ALLOCA is defined
	or not.

gdb/gdbserver:

2014-11-21  Yao Qi  <yao@codesourcery.com>

	* configure.ac: Don't invoke AC_FUNC_ALLOCA.
	(AC_CHECK_HEADERS): Remove malloc.h.
	* configure: Re-generated.
	* config.in: Re-generated.
	* server.h: Don't include alloca.h and malloc.h.
	* gdbreplay.c: Don't check HAVE_ALLOCA_H is defined.
	Don't include malloc.h.

diff --git a/gdb/common/common-defs.h b/gdb/common/common-defs.h
index 4d2e8a7..0a5256a 100644
--- a/gdb/common/common-defs.h
+++ b/gdb/common/common-defs.h
@@ -33,6 +33,7 @@
 #include <stddef.h>
 #include <string.h>
 #include <errno.h>
+#include <alloca.h>
 #include "ansidecl.h"
 #include "libiberty.h"
 #include "pathmax.h"
diff --git a/gdb/configure b/gdb/configure
index 1d6d88b..ade1755 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -10072,196 +10072,6 @@ $as_echo "#define AC_APPLE_UNIVERSAL_BUILD 1" >>confdefs.h
 # Checks for library functions.  #
 # ------------------------------ #
 
-# The Ultrix 4.2 mips builtin alloca declared by alloca.h only works
-# for constant arguments.  Useless!
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for working alloca.h" >&5
-$as_echo_n "checking for working alloca.h... " >&6; }
-if test "${ac_cv_working_alloca_h+set}" = set; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <alloca.h>
-int
-main ()
-{
-char *p = (char *) alloca (2 * sizeof (int));
-			  if (p) return 0;
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_working_alloca_h=yes
-else
-  ac_cv_working_alloca_h=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_working_alloca_h" >&5
-$as_echo "$ac_cv_working_alloca_h" >&6; }
-if test $ac_cv_working_alloca_h = yes; then
-
-$as_echo "#define HAVE_ALLOCA_H 1" >>confdefs.h
-
-fi
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for alloca" >&5
-$as_echo_n "checking for alloca... " >&6; }
-if test "${ac_cv_func_alloca_works+set}" = set; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#ifdef __GNUC__
-# define alloca __builtin_alloca
-#else
-# ifdef _MSC_VER
-#  include <malloc.h>
-#  define alloca _alloca
-# else
-#  ifdef HAVE_ALLOCA_H
-#   include <alloca.h>
-#  else
-#   ifdef _AIX
- #pragma alloca
-#   else
-#    ifndef alloca /* predefined by HP cc +Olibcalls */
-char *alloca ();
-#    endif
-#   endif
-#  endif
-# endif
-#endif
-
-int
-main ()
-{
-char *p = (char *) alloca (1);
-				    if (p) return 0;
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_func_alloca_works=yes
-else
-  ac_cv_func_alloca_works=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_func_alloca_works" >&5
-$as_echo "$ac_cv_func_alloca_works" >&6; }
-
-if test $ac_cv_func_alloca_works = yes; then
-
-$as_echo "#define HAVE_ALLOCA 1" >>confdefs.h
-
-else
-  # The SVR3 libPW and SVR4 libucb both contain incompatible functions
-# that cause trouble.  Some versions do not even contain alloca or
-# contain a buggy version.  If you still want to use their alloca,
-# use ar to extract alloca.o from them instead of compiling alloca.c.
-
-ALLOCA=\${LIBOBJDIR}alloca.$ac_objext
-
-$as_echo "#define C_ALLOCA 1" >>confdefs.h
-
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether \`alloca.c' needs Cray hooks" >&5
-$as_echo_n "checking whether \`alloca.c' needs Cray hooks... " >&6; }
-if test "${ac_cv_os_cray+set}" = set; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#if defined CRAY && ! defined CRAY2
-webecray
-#else
-wenotbecray
-#endif
-
-_ACEOF
-if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
-  $EGREP "webecray" >/dev/null 2>&1; then :
-  ac_cv_os_cray=yes
-else
-  ac_cv_os_cray=no
-fi
-rm -f conftest*
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_os_cray" >&5
-$as_echo "$ac_cv_os_cray" >&6; }
-if test $ac_cv_os_cray = yes; then
-  for ac_func in _getb67 GETB67 getb67; do
-    as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-eval as_val=\$$as_ac_var
-   if test "x$as_val" = x""yes; then :
-
-cat >>confdefs.h <<_ACEOF
-#define CRAY_STACKSEG_END $ac_func
-_ACEOF
-
-    break
-fi
-
-  done
-fi
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking stack direction for C alloca" >&5
-$as_echo_n "checking stack direction for C alloca... " >&6; }
-if test "${ac_cv_c_stack_direction+set}" = set; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test "$cross_compiling" = yes; then :
-  ac_cv_c_stack_direction=0
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-$ac_includes_default
-int
-find_stack_direction ()
-{
-  static char *addr = 0;
-  auto char dummy;
-  if (addr == 0)
-    {
-      addr = &dummy;
-      return find_stack_direction ();
-    }
-  else
-    return (&dummy > addr) ? 1 : -1;
-}
-
-int
-main ()
-{
-  return find_stack_direction () < 0;
-}
-_ACEOF
-if ac_fn_c_try_run "$LINENO"; then :
-  ac_cv_c_stack_direction=1
-else
-  ac_cv_c_stack_direction=-1
-fi
-rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
-  conftest.$ac_objext conftest.beam conftest.$ac_ext
-fi
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_stack_direction" >&5
-$as_echo "$ac_cv_c_stack_direction" >&6; }
-cat >>confdefs.h <<_ACEOF
-#define STACK_DIRECTION $ac_cv_c_stack_direction
-_ACEOF
-
-
-fi
-
 for ac_header in stdlib.h unistd.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
diff --git a/gdb/configure.ac b/gdb/configure.ac
index 2d73669..98eb57b 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -1302,7 +1302,6 @@ AC_C_BIGENDIAN
 # Checks for library functions.  #
 # ------------------------------ #
 
-AC_FUNC_ALLOCA
 AC_FUNC_MMAP
 AC_FUNC_VFORK
 AC_CHECK_FUNCS([canonicalize_file_name realpath getrusage getuid getgid \
diff --git a/gdb/defs.h b/gdb/defs.h
index 1eb43eb..6b63b6a 100644
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -548,27 +548,6 @@ enum gdb_osabi
 extern double atof (const char *);	/* X3.159-1989  4.10.1.1 */
 #endif
 
-/* Various possibilities for alloca.  */
-#ifndef alloca
-#ifdef __GNUC__
-#define alloca __builtin_alloca
-#else /* Not GNU C */
-#ifdef HAVE_ALLOCA_H
-#include <alloca.h>
-#else
-#ifdef _AIX
-#pragma alloca
-#else
-
-/* We need to be careful not to declare this in a way which conflicts with
-   bison.  Bison never declares it as char *, but under various circumstances
-   (like __hpux) we need to use void *.  */
-extern void *alloca ();
-#endif /* Not _AIX */
-#endif /* Not HAVE_ALLOCA_H */
-#endif /* Not GNU C */
-#endif /* alloca not defined */
-
 /* Dynamic target-system-dependent parameters for GDB.  */
 #include "gdbarch.h"
 
diff --git a/gdb/gdbserver/config.in b/gdb/gdbserver/config.in
index 7828bf9..8cac205 100644
--- a/gdb/gdbserver/config.in
+++ b/gdb/gdbserver/config.in
@@ -96,9 +96,6 @@
 /* Define if <thread_db.h> has lwpid_t. */
 #undef HAVE_LWPID_T
 
-/* Define to 1 if you have the <malloc.h> header file. */
-#undef HAVE_MALLOC_H
-
 /* Define to 1 if you have the <memory.h> header file. */
 #undef HAVE_MEMORY_H
 
diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
index 9495905..2266617 100755
--- a/gdb/gdbserver/configure
+++ b/gdb/gdbserver/configure
@@ -605,6 +605,7 @@ WERROR_CFLAGS
 WARN_CFLAGS
 ustinc
 ustlibs
+ALLOCA
 SET_MAKE
 GMAKE_FALSE
 GMAKE_TRUE
@@ -614,7 +615,6 @@ DEPDIR
 am__leading_dot
 host_noncanonical
 target_noncanonical
-ALLOCA
 RANLIB
 AR
 INSTALL_DATA
@@ -4225,197 +4225,6 @@ $as_echo "#define STDC_HEADERS 1" >>confdefs.h
 fi
 
 
-# The Ultrix 4.2 mips builtin alloca declared by alloca.h only works
-# for constant arguments.  Useless!
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for working alloca.h" >&5
-$as_echo_n "checking for working alloca.h... " >&6; }
-if test "${ac_cv_working_alloca_h+set}" = set; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <alloca.h>
-int
-main ()
-{
-char *p = (char *) alloca (2 * sizeof (int));
-			  if (p) return 0;
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_working_alloca_h=yes
-else
-  ac_cv_working_alloca_h=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_working_alloca_h" >&5
-$as_echo "$ac_cv_working_alloca_h" >&6; }
-if test $ac_cv_working_alloca_h = yes; then
-
-$as_echo "#define HAVE_ALLOCA_H 1" >>confdefs.h
-
-fi
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for alloca" >&5
-$as_echo_n "checking for alloca... " >&6; }
-if test "${ac_cv_func_alloca_works+set}" = set; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#ifdef __GNUC__
-# define alloca __builtin_alloca
-#else
-# ifdef _MSC_VER
-#  include <malloc.h>
-#  define alloca _alloca
-# else
-#  ifdef HAVE_ALLOCA_H
-#   include <alloca.h>
-#  else
-#   ifdef _AIX
- #pragma alloca
-#   else
-#    ifndef alloca /* predefined by HP cc +Olibcalls */
-char *alloca ();
-#    endif
-#   endif
-#  endif
-# endif
-#endif
-
-int
-main ()
-{
-char *p = (char *) alloca (1);
-				    if (p) return 0;
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_func_alloca_works=yes
-else
-  ac_cv_func_alloca_works=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_func_alloca_works" >&5
-$as_echo "$ac_cv_func_alloca_works" >&6; }
-
-if test $ac_cv_func_alloca_works = yes; then
-
-$as_echo "#define HAVE_ALLOCA 1" >>confdefs.h
-
-else
-  # The SVR3 libPW and SVR4 libucb both contain incompatible functions
-# that cause trouble.  Some versions do not even contain alloca or
-# contain a buggy version.  If you still want to use their alloca,
-# use ar to extract alloca.o from them instead of compiling alloca.c.
-
-ALLOCA=\${LIBOBJDIR}alloca.$ac_objext
-
-$as_echo "#define C_ALLOCA 1" >>confdefs.h
-
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether \`alloca.c' needs Cray hooks" >&5
-$as_echo_n "checking whether \`alloca.c' needs Cray hooks... " >&6; }
-if test "${ac_cv_os_cray+set}" = set; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#if defined CRAY && ! defined CRAY2
-webecray
-#else
-wenotbecray
-#endif
-
-_ACEOF
-if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
-  $EGREP "webecray" >/dev/null 2>&1; then :
-  ac_cv_os_cray=yes
-else
-  ac_cv_os_cray=no
-fi
-rm -f conftest*
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_os_cray" >&5
-$as_echo "$ac_cv_os_cray" >&6; }
-if test $ac_cv_os_cray = yes; then
-  for ac_func in _getb67 GETB67 getb67; do
-    as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-eval as_val=\$$as_ac_var
-   if test "x$as_val" = x""yes; then :
-
-cat >>confdefs.h <<_ACEOF
-#define CRAY_STACKSEG_END $ac_func
-_ACEOF
-
-    break
-fi
-
-  done
-fi
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking stack direction for C alloca" >&5
-$as_echo_n "checking stack direction for C alloca... " >&6; }
-if test "${ac_cv_c_stack_direction+set}" = set; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test "$cross_compiling" = yes; then :
-  ac_cv_c_stack_direction=0
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-$ac_includes_default
-int
-find_stack_direction ()
-{
-  static char *addr = 0;
-  auto char dummy;
-  if (addr == 0)
-    {
-      addr = &dummy;
-      return find_stack_direction ();
-    }
-  else
-    return (&dummy > addr) ? 1 : -1;
-}
-
-int
-main ()
-{
-  return find_stack_direction () < 0;
-}
-_ACEOF
-if ac_fn_c_try_run "$LINENO"; then :
-  ac_cv_c_stack_direction=1
-else
-  ac_cv_c_stack_direction=-1
-fi
-rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
-  conftest.$ac_objext conftest.beam conftest.$ac_ext
-fi
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_stack_direction" >&5
-$as_echo "$ac_cv_c_stack_direction" >&6; }
-cat >>confdefs.h <<_ACEOF
-#define STACK_DIRECTION $ac_cv_c_stack_direction
-_ACEOF
-
-
-fi
-
-
 # Set the 'development' global.
 . $srcdir/../../bfd/development.sh
 
@@ -4904,7 +4713,7 @@ $as_echo "$as_me: running $SHELL $ac_sub_configure $ac_sub_configure_args --cach
   cd "$ac_popdir"
 
 
-for ac_header in sgtty.h termio.h termios.h sys/reg.h string.h 		 proc_service.h sys/procfs.h linux/elf.h 		 fcntl.h signal.h sys/file.h malloc.h 		 sys/ioctl.h netinet/in.h sys/socket.h netdb.h 		 netinet/tcp.h arpa/inet.h
+for ac_header in sgtty.h termio.h termios.h sys/reg.h string.h 		 proc_service.h sys/procfs.h linux/elf.h 		 fcntl.h signal.h sys/file.h 		 sys/ioctl.h netinet/in.h sys/socket.h netdb.h 		 netinet/tcp.h arpa/inet.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
diff --git a/gdb/gdbserver/configure.ac b/gdb/gdbserver/configure.ac
index 8e5d74f..3864ff4 100644
--- a/gdb/gdbserver/configure.ac
+++ b/gdb/gdbserver/configure.ac
@@ -39,8 +39,6 @@ AC_ARG_PROGRAM
 
 AC_HEADER_STDC
 
-AC_FUNC_ALLOCA
-
 # Set the 'development' global.
 . $srcdir/../../bfd/development.sh
 
@@ -82,7 +80,7 @@ ACX_CONFIGURE_DIR(["../../libiberty"], ["build-libiberty-gdbserver"])
 
 AC_CHECK_HEADERS(sgtty.h termio.h termios.h sys/reg.h string.h dnl
 		 proc_service.h sys/procfs.h linux/elf.h dnl
-		 fcntl.h signal.h sys/file.h malloc.h dnl
+		 fcntl.h signal.h sys/file.h dnl
 		 sys/ioctl.h netinet/in.h sys/socket.h netdb.h dnl
 		 netinet/tcp.h arpa/inet.h)
 AC_CHECK_FUNCS(pread pwrite pread64 readlink)
diff --git a/gdb/gdbserver/gdbreplay.c b/gdb/gdbserver/gdbreplay.c
index c70abef..dedf2bb 100644
--- a/gdb/gdbserver/gdbreplay.c
+++ b/gdb/gdbserver/gdbreplay.c
@@ -48,12 +48,9 @@
 #if HAVE_NETINET_TCP_H
 #include <netinet/tcp.h>
 #endif
-#if HAVE_ALLOCA_H
+
 #include <alloca.h>
-#endif
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
+
 #if USE_WIN32API
 #include <winsock2.h>
 #endif
diff --git a/gdb/gdbserver/server.h b/gdb/gdbserver/server.h
index cac73e9..02d751a 100644
--- a/gdb/gdbserver/server.h
+++ b/gdb/gdbserver/server.h
@@ -29,15 +29,6 @@ gdb_static_assert (sizeof (CORE_ADDR) >= sizeof (void *));
 
 #include "version.h"
 
-#ifdef HAVE_ALLOCA_H
-#include <alloca.h>
-#endif
-/* On some systems such as MinGW, alloca is declared in malloc.h
-   (there is no alloca.h).  */
-#if HAVE_MALLOC_H
-#include <malloc.h>
-#endif
-
 #if !HAVE_DECL_STRERROR
 #ifndef strerror
 extern char *strerror (int);	/* X3.159-1989  4.11.6.2 */
diff --git a/gdb/utils.c b/gdb/utils.c
index 3915b58..ff5c00d 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -2913,7 +2913,7 @@ gdb_realpath (const char *filename)
      pathconf()) making it impossible to pass a correctly sized buffer
      to realpath() (it could always overflow).  On those systems, we
      skip this.  */
-#if defined (HAVE_REALPATH) && defined (_PC_PATH_MAX) && defined(HAVE_ALLOCA)
+#if defined (HAVE_REALPATH) && defined (_PC_PATH_MAX)
   {
     /* Find out the max path size.  */
     long path_max = pathconf ("/", _PC_PATH_MAX);