Re: [PATCH] For broken exception handling in GDB on AIX platform

[Nitish Kumar Mishra]

Hi Jeff,

Our AIX team is parallely working on the issue that why EH is not
working with static linking on AIX. For time being this patch
will be work around for the issue.


On Thu, Mar 30, 2017 at 1:07 AM, Jeff Law  wrote:
> On 03/26/2017 06:05 PM, Joel Brobecker wrote:
>>
>> Hello,
>>
>>> I got some review comment from Bernhard Reutner-Fischer, and I have
>>> updated the patch accordingly.
>>> This patch is for bug opened
>>> here:https://sourceware.org/bugzilla/show_bug.cgi?id=21187
>>
>>
>> This patch has been identified as one of the desirable patches
>> to have for the GDB 8.0 release, for which we are hoping to create
>> the branch ASAP. Without this patch, it would be difficult for
>> users on AIX to build a functional debugger.
>>
>> Would it be possible to help Nitish through the review and approval
>> process?
>>
>> Here is a ChangeLog entry:
>>
>> * configure.ac: Add support for --disable-staticlib.
>> * configure: Regenerate.
>>
>> Can someone review the patch, please?
>
> Isn't this just papering over the problem by just disabling static linking
> rather than digging into why EH is not working with static linking on AIX?
>
> It'd be different if there was some fundamental reason why EH could not work
> with static linking on AIX.
>
> Am I missing something?
>
> Jeff
>

[PATCH] For broken exception handling in GDB on AIX platform

[Nitish Kumar Mishra]

Hi,
The patch is for the broken exception handling in GDB on AIX platform.
When linked statically with libstdc++ and libgcc on AIX platform, GDB
is facing broken exception handling issues.
Following is the error output when GDB is linked statically with
mentioned libraries: (GDB-7.12.1, built with GCC-6.2, 64 bit mode, AIX
platform):

# ./gdb
GNU gdb (GDB) 7.12.1
Copyright (C) 2017 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "powerpc64-ibm-aix7.2.0.0".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
.
Find the GDB manual and other documentation resources online at:
.
For help, type "help".
Type "apropos word" to search for commands related to "word".
(gdb) kill
terminate called after throwing an instance of 'gdb_exception_RETURN_MASK_ERROR'
IOT/Abort trap (core dumped)


The issue has been discussed here:
https://sourceware.org/ml/gdb/2017-02/msg00047.html

I have manually built and tested GDB-7.12.1 with this patch on AIX-7.2
and Ubuntu-16.04 with GCC-6.2 and GCC-4.8.5. On both operating system
GDB is working fine with the patch. I generated configure file using
autoconf-2.64.

The attached patch is for configure.ac file in binutils-gdb, in which
one more option "--disable-staticlib" is implemented to link libstdc++
and libgcc dynamically.
I believe this issue is specific to AIX platform.

Please find the attachment for patch file, and ChangeLog file.

Thanks and Regards,
Nitish K Mishra
2016-03-01  Nitish K Mishra  

* configure.ac: Include one more option "--disable-staticlib"
to link libstdc++ and libgcc dynamically.diff --git a/configure.ac b/configure.ac
index 3ec86c1..9bbb024 100644
--- a/configure.ac
+++ b/configure.ac
@@ -471,6 +471,13 @@ ENABLE_LIBSTDCXX=default)
   noconfigdirs="$noconfigdirs target-libstdc++-v3"
 fi]
 
+AC_ARG_ENABLE(staticlib,
+AS_HELP_STRING([--disable-staticlib],
+  [do not link libstdc++ and libgcc library statically]),
+have_static_lib=$enableval,
+have_static_lib=yes)
+
+
 # If this is accelerator compiler and its target is intelmic we enable
 # target liboffloadmic by default.  If this is compiler with offloading
 # for intelmic we enable host liboffloadmic by default.  Otherwise
@@ -1406,9 +1413,10 @@ if test -z "$LD"; then
   fi
 fi
 
-# Check whether -static-libstdc++ -static-libgcc is supported.
-have_static_libs=no
-if test "$GCC" = yes; then
+# If enable_staticlib is set for configuration, check whether -static-libstdc++ -static-libgcc is supported
+
+if test "$have_static_lib" = yes; then
+ if test "$GCC" = yes; then
   saved_LDFLAGS="$LDFLAGS"
 
   LDFLAGS="$LDFLAGS -static-libstdc++ -static-libgcc"
@@ -1424,6 +1432,7 @@ int main() {}],
   AC_LANG_POP(C++)
 
   LDFLAGS="$saved_LDFLAGS"
+ fi
 fi
 
 ACX_PROG_GNAT
@@ -1741,6 +1750,9 @@ AC_ARG_WITH(stage1-ldflags,
  # trust that they are doing what they want.
  if test "$stage1_libs" = "" -a "$have_static_libs" = yes; then
stage1_ldflags="-static-libstdc++ -static-libgcc"
+   else
+  # If static lib is disabled.
+   stage1_ldflags=""
  fi])
 AC_SUBST(stage1_ldflags)
 
@@ -1768,8 +1780,11 @@ AC_ARG_WITH(boot-ldflags,
  # In stages 2 and 3, default to linking libstdc++ and libgcc
  # statically.  But if the user explicitly specified the libraries to
  # use, trust that they are doing what they want.
- if test "$poststage1_libs" = ""; then
+ if test "$poststage1_libs" = "" -a "$have_static_lib" = yes; then
poststage1_ldflags="-static-libstdc++ -static-libgcc"
+   else
+   # If static lib is disabled.
+   poststage1_ldflags=""
  fi])
 AC_SUBST(poststage1_ldflags)
 

Re: [PATCH] For broken exception handling in GDB on AIX platform

[Nitish Kumar Mishra]

Hi,
I have opened a defect for the same here:
https://sourceware.org/bugzilla/show_bug.cgi?id=21187

Thanks and Regards,
Nitish K Mishra

On Wed, Mar 1, 2017 at 1:25 PM, Nitish Kumar Mishra
 wrote:
> Hi,
> The patch is for the broken exception handling in GDB on AIX platform.
> When linked statically with libstdc++ and libgcc on AIX platform, GDB
> is facing broken exception handling issues.
> Following is the error output when GDB is linked statically with
> mentioned libraries: (GDB-7.12.1, built with GCC-6.2, 64 bit mode, AIX
> platform):
>
> # ./gdb
> GNU gdb (GDB) 7.12.1
> Copyright (C) 2017 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "powerpc64-ibm-aix7.2.0.0".
> Type "show configuration" for configuration details.
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>.
> Find the GDB manual and other documentation resources online at:
> <http://www.gnu.org/software/gdb/documentation/>.
> For help, type "help".
> Type "apropos word" to search for commands related to "word".
> (gdb) kill
> terminate called after throwing an instance of 
> 'gdb_exception_RETURN_MASK_ERROR'
> IOT/Abort trap (core dumped)
>
>
> The issue has been discussed here:
> https://sourceware.org/ml/gdb/2017-02/msg00047.html
>
> I have manually built and tested GDB-7.12.1 with this patch on AIX-7.2
> and Ubuntu-16.04 with GCC-6.2 and GCC-4.8.5. On both operating system
> GDB is working fine with the patch. I generated configure file using
> autoconf-2.64.
>
> The attached patch is for configure.ac file in binutils-gdb, in which
> one more option "--disable-staticlib" is implemented to link libstdc++
> and libgcc dynamically.
> I believe this issue is specific to AIX platform.
>
> Please find the attachment for patch file, and ChangeLog file.
>
> Thanks and Regards,
> Nitish K Mishra

Re: [PATCH] For broken exception handling in GDB on AIX platform

[Nitish Kumar Mishra]

Hi,

I have update the patch according to some comments from GDB community.
Please find the attachments.

Thanks and Regards,
Nitish K Mishra

On Wed, Mar 1, 2017 at 1:33 PM, Nitish Kumar Mishra
 wrote:
> Hi,
> I have opened a defect for the same here:
> https://sourceware.org/bugzilla/show_bug.cgi?id=21187
>
> Thanks and Regards,
> Nitish K Mishra
>
> On Wed, Mar 1, 2017 at 1:25 PM, Nitish Kumar Mishra
>  wrote:
>> Hi,
>> The patch is for the broken exception handling in GDB on AIX platform.
>> When linked statically with libstdc++ and libgcc on AIX platform, GDB
>> is facing broken exception handling issues.
>> Following is the error output when GDB is linked statically with
>> mentioned libraries: (GDB-7.12.1, built with GCC-6.2, 64 bit mode, AIX
>> platform):
>>
>> # ./gdb
>> GNU gdb (GDB) 7.12.1
>> Copyright (C) 2017 Free Software Foundation, Inc.
>> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
>> This is free software: you are free to change and redistribute it.
>> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
>> and "show warranty" for details.
>> This GDB was configured as "powerpc64-ibm-aix7.2.0.0".
>> Type "show configuration" for configuration details.
>> For bug reporting instructions, please see:
>> <http://www.gnu.org/software/gdb/bugs/>.
>> Find the GDB manual and other documentation resources online at:
>> <http://www.gnu.org/software/gdb/documentation/>.
>> For help, type "help".
>> Type "apropos word" to search for commands related to "word".
>> (gdb) kill
>> terminate called after throwing an instance of 
>> 'gdb_exception_RETURN_MASK_ERROR'
>> IOT/Abort trap (core dumped)
>>
>>
>> The issue has been discussed here:
>> https://sourceware.org/ml/gdb/2017-02/msg00047.html
>>
>> I have manually built and tested GDB-7.12.1 with this patch on AIX-7.2
>> and Ubuntu-16.04 with GCC-6.2 and GCC-4.8.5. On both operating system
>> GDB is working fine with the patch. I generated configure file using
>> autoconf-2.64.
>>
>> The attached patch is for configure.ac file in binutils-gdb, in which
>> one more option "--disable-staticlib" is implemented to link libstdc++
>> and libgcc dynamically.
>> I believe this issue is specific to AIX platform.
>>
>> Please find the attachment for patch file, and ChangeLog file.
>>
>> Thanks and Regards,
>> Nitish K Mishra
2016-03-01  Nitish K Mishra  

* configure.ac: Include one more option "--disable-staticlib"
to link libstdc++ and libgcc dynamically.diff --git a/configure.ac b/configure.ac
index 3ec86c1..c400251 100644
--- a/configure.ac
+++ b/configure.ac
@@ -140,7 +140,7 @@ host_libs="intl libiberty opcodes bfd readline tcl tk itcl libgui zlib libbacktr
 # binutils, gas and ld appear in that order because it makes sense to run
 # "make check" in that particular order.
 # If --enable-gold is used, "gold" may replace "ld".
-host_tools="texinfo flex bison binutils gas ld fixincludes gcc cgen sid sim gdb gprof etc expect dejagnu m4 utils guile fastjar gnattools libcc1 gotools"
+host_tools="flex bison binutils gas ld fixincludes gcc cgen sid sim gdb gprof etc expect dejagnu m4 utils guile fastjar gnattools libcc1 gotools"
 
 # libgcj represents the runtime libraries only used by gcj.
 libgcj="target-libffi \
@@ -337,7 +337,7 @@ case "${ENABLE_GOLD}" in
   *-*-elf* | *-*-sysv4* | *-*-unixware* | *-*-eabi* | hppa*64*-*-hpux* \
   | *-*-linux* | *-*-gnu* | frv-*-uclinux* | *-*-irix5* | *-*-irix6* \
   | *-*-netbsd* | *-*-openbsd* | *-*-freebsd* | *-*-dragonfly* \
-  | *-*-solaris2* | *-*-nto* | *-*-nacl* | *-*-fuchsia*)
+  | *-*-solaris2* | *-*-nto* | *-*-nacl*)
 case "${target}" in
   *-*-linux*aout* | *-*-linux*oldld*)
 ;;
@@ -471,6 +471,13 @@ ENABLE_LIBSTDCXX=default)
   noconfigdirs="$noconfigdirs target-libstdc++-v3"
 fi]
 
+AC_ARG_ENABLE(staticlib,
+AS_HELP_STRING([--disable-staticlib],
+  [do not link libstdc++ and libgcc library statically, default is static linking]),
+ENABLE_STATICLIB=$enableval,
+ENABLE_STATICLIB=yes)
+
+
 # If this is accelerator compiler and its target is intelmic we enable
 # target liboffloadmic by default.  If this is compiler with offloading
 # for intelmic we enable host liboffloadmic by default.  Otherwise
@@ -1406,9 +1413,10 @@ if test -z "$LD"; then
   fi
 fi
 
-# Check whether -static-libstdc++ -static-libgcc is supported.
+# If ENABLE_STATICLIB is set for configuration, check whether -st

[PATCH] For broken exception handling in GDB on AIX platform

[Nitish Kumar Mishra]

Hi,

I got some review comment from Bernhard Reutner-Fischer, and I have
updated the patch accordingly.
This patch is for bug opened
here:https://sourceware.org/bugzilla/show_bug.cgi?id=21187

Please find the attachment below.

Thanks and Regards,
Nitish K Mishra.
diff --git a/configure.ac b/configure.ac
index 3ec86c1..c400251 100644
--- a/configure.ac
+++ b/configure.ac
@@ -471,6 +471,13 @@ ENABLE_LIBSTDCXX=default)
   noconfigdirs="$noconfigdirs target-libstdc++-v3"
 fi]
 
+AC_ARG_ENABLE(staticlib,
+AS_HELP_STRING([--disable-staticlib],
+  [do not link libstdc++ and libgcc library statically, default is static linking]),
+ENABLE_STATICLIB=$enableval,
+ENABLE_STATICLIB=yes)
+
+
 # If this is accelerator compiler and its target is intelmic we enable
 # target liboffloadmic by default.  If this is compiler with offloading
 # for intelmic we enable host liboffloadmic by default.  Otherwise
@@ -1406,9 +1413,10 @@ if test -z "$LD"; then
   fi
 fi
 
-# Check whether -static-libstdc++ -static-libgcc is supported.
+# If ENABLE_STATICLIB is set for configuration, check whether -static-libstdc++ -static-libgcc is supported
 have_static_libs=no
-if test "$GCC" = yes; then
+if test "$ENABLE_STATICLIB" = yes; then
+ if test "$GCC" = yes; then
   saved_LDFLAGS="$LDFLAGS"
 
   LDFLAGS="$LDFLAGS -static-libstdc++ -static-libgcc"
@@ -1424,6 +1432,7 @@ int main() {}],
   AC_LANG_POP(C++)
 
   LDFLAGS="$saved_LDFLAGS"
+ fi
 fi
 
 ACX_PROG_GNAT
@@ -1741,6 +1750,9 @@ AC_ARG_WITH(stage1-ldflags,
  # trust that they are doing what they want.
  if test "$stage1_libs" = "" -a "$have_static_libs" = yes; then
stage1_ldflags="-static-libstdc++ -static-libgcc"
+   else
+  # If static lib is disabled.
+   stage1_ldflags=""
  fi])
 AC_SUBST(stage1_ldflags)
 
@@ -1768,8 +1780,11 @@ AC_ARG_WITH(boot-ldflags,
  # In stages 2 and 3, default to linking libstdc++ and libgcc
  # statically.  But if the user explicitly specified the libraries to
  # use, trust that they are doing what they want.
- if test "$poststage1_libs" = ""; then
+ if test "$poststage1_libs" = "" -a "$have_static_libs" = yes; then
poststage1_ldflags="-static-libstdc++ -static-libgcc"
+   else
+   # If static library linking is disabled.
+   poststage1_ldflags=""
  fi])
 AC_SUBST(poststage1_ldflags)