Re: RFA: Try to include libunwind-ia64.h in libunwind-frame.h

[Pedro Alves <palves@redhat.com>]

On 02/13/2012 07:26 PM, Jan Kratochvil wrote:
> On Mon, 13 Feb 2012 20:19:45 +0100, Pedro Alves wrote:
>> On 02/13/2012 07:02 PM, Jan Kratochvil wrote:
>>> It is required for ia64 but it can be used even with non-ia64 archs.
>>
>> How?  AFAICS, no other target installs the libunwind sniffer.  It's just
>> dead code on other archs, if I'm reading the code correctly.
> 
> I see now.  I did not know.  Sure in this case this patch of mine was wrong.
> I will therefore make libunwind usable only with ia64, this will be different
> patch removing some parts of gdb/ code.

I was only thinking of the below.  Would this work for everyone?

I don't have a cross build of libunwind for ia64 handy, but I assume
this works, given the previous patches...

2012-02-13  Tristan Gingold  <gingold@adacore.com>
	    Pedro Alves  <palves@redhat.com>

	* ia64-tdep.c: Do not include libunwind-ia64.h.
	* libunwind-frame.h: Include libunwind-ia64.h instead of
	libunwind.h.
	* configure.ac (--with-libunwind, $enable_libunwind): Don't check
	for libunwind.h existence.
	* configure, config.in: Regenerate.
---

 gdb/config.in         |    3 ---
 gdb/configure         |   22 +++++++++-------------
 gdb/configure.ac      |    6 +++---
 gdb/ia64-tdep.c       |    1 -
 gdb/libunwind-frame.h |    7 ++++++-
 5 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/gdb/config.in b/gdb/config.in
index bae1763..194cc7d 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -242,9 +242,6 @@
 /* Define if libunwind library is being used. */
 #undef HAVE_LIBUNWIND

-/* Define to 1 if you have the <libunwind.h> header file. */
-#undef HAVE_LIBUNWIND_H
-
 /* Define to 1 if you have the <libunwind-ia64.h> header file. */
 #undef HAVE_LIBUNWIND_IA64_H

diff --git a/gdb/configure b/gdb/configure
index 2566410..96a82ee 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -8252,21 +8252,19 @@ if test "${with_libunwind+set}" = set; then :
 esac
 else

-  for ac_header in libunwind.h libunwind-ia64.h
+  for ac_header in libunwind-ia64.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" "$ac_includes_default"
-eval as_val=\$$as_ac_Header
-   if test "x$as_val" = x""yes; then :
+  ac_fn_c_check_header_mongrel "$LINENO" "libunwind-ia64.h" "ac_cv_header_libunwind_ia64_h" "$ac_includes_default"
+if test "x$ac_cv_header_libunwind_ia64_h" = x""yes; then :
   cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
+#define HAVE_LIBUNWIND_IA64_H 1
 _ACEOF

 fi

 done

-  if test x"$ac_cv_header_libunwind_h" = xyes -a x"$ac_cv_header_libunwind_ia64_h" = xyes; then
+  if x"$ac_cv_header_libunwind_ia64_h" = xyes; then
     enable_libunwind=yes;
   fi

@@ -8274,14 +8272,12 @@ fi


 if test x"$enable_libunwind" = xyes; then
-  for ac_header in libunwind.h libunwind-ia64.h
+  for ac_header in libunwind-ia64.h
 do :
-  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
-ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
-eval as_val=\$$as_ac_Header
-   if test "x$as_val" = x""yes; then :
+  ac_fn_c_check_header_mongrel "$LINENO" "libunwind-ia64.h" "ac_cv_header_libunwind_ia64_h" "$ac_includes_default"
+if test "x$ac_cv_header_libunwind_ia64_h" = x""yes; then :
   cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
+#define HAVE_LIBUNWIND_IA64_H 1
 _ACEOF

 fi
diff --git a/gdb/configure.ac b/gdb/configure.ac
index 1b11adb..f7c987d 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -348,14 +348,14 @@ AS_HELP_STRING([--with-libunwind], [use libunwind frame unwinding support]),
   no)   enable_libunwind=no ;;
   *)    AC_MSG_ERROR(bad value ${withval} for GDB with-libunwind option) ;;
 esac],[
-  AC_CHECK_HEADERS(libunwind.h libunwind-ia64.h)
-  if test x"$ac_cv_header_libunwind_h" = xyes -a x"$ac_cv_header_libunwind_ia64_h" = xyes; then
+  AC_CHECK_HEADERS(libunwind-ia64.h)
+  if x"$ac_cv_header_libunwind_ia64_h" = xyes; then
     enable_libunwind=yes;
   fi
 ])

 if test x"$enable_libunwind" = xyes; then
-  AC_CHECK_HEADERS(libunwind.h libunwind-ia64.h)
+  AC_CHECK_HEADERS(libunwind-ia64.h)
   AC_DEFINE(HAVE_LIBUNWIND, 1, [Define if libunwind library is being used.])
   CONFIG_OBS="$CONFIG_OBS libunwind-frame.o"
   CONFIG_DEPS="$CONFIG_DEPS libunwind-frame.o"
diff --git a/gdb/ia64-tdep.c b/gdb/ia64-tdep.c
index a297ecc..a36dc22 100644
--- a/gdb/ia64-tdep.c
+++ b/gdb/ia64-tdep.c
@@ -43,7 +43,6 @@
 #ifdef HAVE_LIBUNWIND_IA64_H
 #include "elf/ia64.h"           /* for PT_IA_64_UNWIND value */
 #include "libunwind-frame.h"
-#include "libunwind-ia64.h"

 /* Note: KERNEL_START is supposed to be an address which is not going
          to ever contain any valid unwind info.  For ia64 linux, the choice
diff --git a/gdb/libunwind-frame.h b/gdb/libunwind-frame.h
index 0251819..922fdcb 100644
--- a/gdb/libunwind-frame.h
+++ b/gdb/libunwind-frame.h
@@ -29,7 +29,12 @@ struct gdbarch;
 #ifndef LIBUNWIND_FRAME_H
 #define LIBUNWIND_FRAME_H 1

-#include "libunwind.h"
+/* IA64 is the only target that currently uses libunwind.  If some
+   other target wants to use it, we will need to do some abstracting
+   in order to make it possible to have more than one libunwind-frame
+   instance.  Including "libunwind.h" is wrong as that picks up the
+   version for the host gdb is running on.  */
+#include "libunwind-ia64.h"

 struct libunwind_descr
 {