diff mbox

libgcc: On AIX, increase chances to find landing pads for exceptions

Message ID 56D58697.7070400@ssi-schaefer.com
State New
Headers show

Commit Message

Michael Haubenwallner March 1, 2016, 12:09 p.m. UTC 
Hi David,

On 02/10/2016 10:52 AM, Michael Haubenwallner wrote:
<snip>
>> There are two remaining issues:
>>
>> 1) FDEs with overlapping ranges causing problems with exceptions.  I'm
>> not sure of the best way to work around this.  Your patch is one
>> possible solution.
> 
> This patch is not meant as a final solution, but to improve current
> situation with broken build systems exporting even _GLOBAL__ symbols.
> I'm about to prepare another libtool patch to fix that one.

so this is the libtool patch I'm about to submit.

What do you think? Reasonable?

Thanks!
/haubi/

Comments

David Edelsohn March 1, 2016, 1:14 p.m. UTC | #1 
On Tue, Mar 1, 2016 at 7:09 AM, Michael Haubenwallner
<michael.haubenwallner@ssi-schaefer.com> wrote:
> Hi David,
>
> On 02/10/2016 10:52 AM, Michael Haubenwallner wrote:
> <snip>
>>> There are two remaining issues:
>>>
>>> 1) FDEs with overlapping ranges causing problems with exceptions.  I'm
>>> not sure of the best way to work around this.  Your patch is one
>>> possible solution.
>>
>> This patch is not meant as a final solution, but to improve current
>> situation with broken build systems exporting even _GLOBAL__ symbols.
>> I'm about to prepare another libtool patch to fix that one.
>
> so this is the libtool patch I'm about to submit.
>
> What do you think? Reasonable?

I don't think that Ian really cares about this.

I guess that the patch is reasonable, but the libtool command is
becoming extremely complicated.

- David
diff mbox

Patch

From 18daacef170d0b0ad67869173cd521dc991d2264 Mon Sep 17 00:00:00 2001
From: Michael Haubenwallner <michael.haubenwallner@ssi-schaefer.com>
Date: Mon, 29 Feb 2016 16:07:32 +0100
Subject: [PATCH] AIX: stop exporting _GLOBAL__ syms

* m4/libtool.m4 (_LT_LINKER_SHLIBS): On AIX, GNU g++ generates
_GLOBAL__* symbols as landing pads for C++ exceptions.  These symbols
must not be exported from shared libraries, or exception handling may
break for applications with runtime linking enabled.
---
 m4/libtool.m4 | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/m4/libtool.m4 b/m4/libtool.m4
index ee292af..656d2cd 100644
--- a/m4/libtool.m4
+++ b/m4/libtool.m4
@@ -4939,9 +4939,9 @@  m4_if([$1], [CXX], [
     # it in the Import File for the 'aix-soname' feature, so we have
     # to replace the "-B" option with "-P" for AIX nm.
     if $NM -V 2>&1 | $GREP 'GNU' > /dev/null; then
-      _LT_TAGVAR(export_symbols_cmds, $1)='$NM -Bpg $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "W")) && ([substr](\$ 3,1,1) != ".")) { if (\$ 2 == "W") { print \$ 3 " weak" } else { print \$ 3 } } }'\'' | sort -u > $export_symbols'
+      _LT_TAGVAR(export_symbols_cmds, $1)='$NM -Bpg $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "W")) && ([substr](\$ 3,1,1) != ".") && ([substr](\$ 3,1,9) != "_GLOBAL__")) { if (\$ 2 == "W") { print \$ 3 " weak" } else { print \$ 3 } } }'\'' | sort -u > $export_symbols'
     else
-      _LT_TAGVAR(export_symbols_cmds, $1)='`func_echo_all $NM | $SED -e '\''s/B\([[^B]]*\)$/P\1/'\''` -PCpgl $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "L") || (\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) && ([substr](\$ 1,1,1) != ".")) { if ((\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) { print \$ 1 " weak" } else { print \$ 1 } } }'\'' | sort -u > $export_symbols'
+      _LT_TAGVAR(export_symbols_cmds, $1)='`func_echo_all $NM | $SED -e '\''s/B\([[^B]]*\)$/P\1/'\''` -PCpgl $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "L") || (\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) && ([substr](\$ 1,1,1) != ".") && ([substr](\$ 1,1,9) != "_GLOBAL__")) { if ((\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) { print \$ 1 " weak" } else { print \$ 1 } } }'\'' | sort -u > $export_symbols'
     fi
     ;;
   pw32*)
@@ -5394,9 +5394,9 @@  _LT_EOF
 	# it in the Import File for the 'aix-soname' feature, so we have
 	# to replace the "-B" option with "-P" for AIX nm.
 	if $NM -V 2>&1 | $GREP 'GNU' > /dev/null; then
-	  _LT_TAGVAR(export_symbols_cmds, $1)='$NM -Bpg $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "W")) && ([substr](\$ 3,1,1) != ".")) { if (\$ 2 == "W") { print \$ 3 " weak" } else { print \$ 3 } } }'\'' | sort -u > $export_symbols'
+	  _LT_TAGVAR(export_symbols_cmds, $1)='$NM -Bpg $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "W")) && ([substr](\$ 3,1,1) != ".") && ([substr](\$ 3,1,9) != "_GLOBAL__")) { if (\$ 2 == "W") { print \$ 3 " weak" } else { print \$ 3 } } }'\'' | sort -u > $export_symbols'
 	else
-	  _LT_TAGVAR(export_symbols_cmds, $1)='`func_echo_all $NM | $SED -e '\''s/B\([[^B]]*\)$/P\1/'\''` -PCpgl $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "L") || (\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) && ([substr](\$ 1,1,1) != ".")) { if ((\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) { print \$ 1 " weak" } else { print \$ 1 } } }'\'' | sort -u > $export_symbols'
+	  _LT_TAGVAR(export_symbols_cmds, $1)='`func_echo_all $NM | $SED -e '\''s/B\([[^B]]*\)$/P\1/'\''` -PCpgl $libobjs $convenience | awk '\''{ if (((\$ 2 == "T") || (\$ 2 == "D") || (\$ 2 == "B") || (\$ 2 == "L") || (\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) && ([substr](\$ 1,1,1) != ".") && ([substr](\$ 1,1,9) != "_GLOBAL__")) { if ((\$ 2 == "W") || (\$ 2 == "V") || (\$ 2 == "Z")) { print \$ 1 " weak" } else { print \$ 1 } } }'\'' | sort -u > $export_symbols'
 	fi
 	aix_use_runtimelinking=no
 
-- 
2.4.6