Re: [PATCH] libstdc++: use a link test to test for -Wl,-z,relro

2020-09-22 Thread Jonathan Wakely via Gcc-patches 

On 22/09/20 09:40 +, JonY via Libstdc++ wrote:

On 9/22/20 8:50 AM, Jonathan Wakely wrote:


I don't see a patch, or any previous email to the libstdc++ list.

Please resend with the patch, CCing libstdc++@

Thanks.





Resent for the record.


Thanks.


I've been told it might not be appropriate
because some targets cannot link yet and therefore will fail incorrectly.



We only use the GLIBCXX_CHECK_LINKER_FEATURES macro for native builds,
or for specific cross targets.  And we already do AC_TRY_LINK just
before the relro check, so I think it's probably OK. But I admit to
not fully understanding this.



Currently, the linker support is misdetected since binutils can support
multiple targets. MinGW/Cygwin PE formats don't support such a flag.



From: Jonathan Yong <10wa...@gmail.com>
Date: Sun, 22 Mar 2020 01:59:37 + (+0800)
Subject: libstdc++: use a link test to test for -Wl,-z,relro
X-Git-Url: 
https://repo.or.cz/gcc/cygwin-gcc.git/commitdiff_plain/1b20e03e7468760828bfc70fc5e811b5b3738adf

libstdc++: use a link test to test for -Wl,-z,relro

Do a link test instead of just a grep. The linker can
support multiple targets, but not all targets can use it.

Signed-off-by: Jonathan Yong <10wa...@gmail.com>
---

diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index bc7d137dc74..209aa3a91f3 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -274,7 +274,16 @@ AC_DEFUN([GLIBCXX_CHECK_LINKER_FEATURES], [
  ac_ld_relro=no
  if test x"$with_gnu_ld" = x"yes"; then
AC_MSG_CHECKING([for ld that supports -Wl,-z,relro])
-cxx_z_relo=`$LD -v --help 2>/dev/null | grep "z relro"`
+ac_save_ldflags="$LDFLAGS"
+LDFLAGS="$LDFLAGS -Wl,-z,relro"
+AC_LINK_IFELSE([
+  AC_LANG_SOURCE(
+[[int main() { return 0; }]]
+  )],
+  [cxx_z_relo="1"],
+  [cxx_z_relo=""])
+   LDFLAGS="$ac_save_ldflags"
+
if test -n "$cxx_z_relo"; then
  OPT_LDFLAGS="-Wl,-z,relro"
  ac_ld_relro=yes

Re: [PATCH] libstdc++: use a link test to test for -Wl,-z,relro

2020-09-22 Thread JonY via Gcc-patches 
On 9/22/20 8:50 AM, Jonathan Wakely wrote:
> 
> I don't see a patch, or any previous email to the libstdc++ list.
> 
> Please resend with the patch, CCing libstdc++@
> 
> Thanks.
> 
> 
> 

Resent for the record. I've been told it might not be appropriate
because some targets cannot link yet and therefore will fail incorrectly.

Currently, the linker support is misdetected since binutils can support
multiple targets. MinGW/Cygwin PE formats don't support such a flag.
From: Jonathan Yong <10wa...@gmail.com>
Date: Sun, 22 Mar 2020 01:59:37 + (+0800)
Subject: libstdc++: use a link test to test for -Wl,-z,relro
X-Git-Url: 
https://repo.or.cz/gcc/cygwin-gcc.git/commitdiff_plain/1b20e03e7468760828bfc70fc5e811b5b3738adf

libstdc++: use a link test to test for -Wl,-z,relro

Do a link test instead of just a grep. The linker can
support multiple targets, but not all targets can use it.

Signed-off-by: Jonathan Yong <10wa...@gmail.com>
---

diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index bc7d137dc74..209aa3a91f3 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -274,7 +274,16 @@ AC_DEFUN([GLIBCXX_CHECK_LINKER_FEATURES], [
   ac_ld_relro=no
   if test x"$with_gnu_ld" = x"yes"; then
 AC_MSG_CHECKING([for ld that supports -Wl,-z,relro])
-cxx_z_relo=`$LD -v --help 2>/dev/null | grep "z relro"`
+ac_save_ldflags="$LDFLAGS"
+LDFLAGS="$LDFLAGS -Wl,-z,relro"
+AC_LINK_IFELSE([
+  AC_LANG_SOURCE(
+[[int main() { return 0; }]]
+  )],
+  [cxx_z_relo="1"],
+  [cxx_z_relo=""])
+   LDFLAGS="$ac_save_ldflags"
+
 if test -n "$cxx_z_relo"; then
   OPT_LDFLAGS="-Wl,-z,relro"
   ac_ld_relro=yes


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Re: [PATCH] libstdc++: use a link test to test for -Wl,-z,relro

2020-09-22 Thread Jonathan Wakely via Gcc-patches 

On 16/09/20 12:11 +, JonY via Libstdc++ wrote:

On 9/13/20 3:37 PM, JonY wrote:

On 9/10/20 2:23 PM, JonY wrote:

Do a link test instead of just a grep. The linker can
support multiple targets, but not all targets can use it.

Cygwin/MinGW ld can support ELF but the PE format for Windows itself
does not support such a feature. Attached patch OK?

I'm not confident with regenerating configure due to some unrelated
changes added, can someone else help with that?



Ping?



Ping 2?



I don't see a patch, or any previous email to the libstdc++ list.

Please resend with the patch, CCing libstdc++@

Thanks.

Re: [PATCH] libstdc++: use a link test to test for -Wl,-z,relro

2020-09-16 Thread JonY via Gcc-patches 
On 9/13/20 3:37 PM, JonY wrote:
> On 9/10/20 2:23 PM, JonY wrote:
>> Do a link test instead of just a grep. The linker can
>> support multiple targets, but not all targets can use it.
>>
>> Cygwin/MinGW ld can support ELF but the PE format for Windows itself
>> does not support such a feature. Attached patch OK?
>>
>> I'm not confident with regenerating configure due to some unrelated
>> changes added, can someone else help with that?
>>
> 
> Ping?
> 

Ping 2?



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Re: [PATCH] libstdc++: use a link test to test for -Wl,-z,relro

2020-09-13 Thread JonY via Gcc-patches 
On 9/10/20 2:23 PM, JonY wrote:
> Do a link test instead of just a grep. The linker can
> support multiple targets, but not all targets can use it.
> 
> Cygwin/MinGW ld can support ELF but the PE format for Windows itself
> does not support such a feature. Attached patch OK?
> 
> I'm not confident with regenerating configure due to some unrelated
> changes added, can someone else help with that?
> 

Ping?



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[PATCH] libstdc++: use a link test to test for -Wl,-z,relro

2020-09-10 Thread JonY via Gcc-patches 
Do a link test instead of just a grep. The linker can
support multiple targets, but not all targets can use it.

Cygwin/MinGW ld can support ELF but the PE format for Windows itself
does not support such a feature. Attached patch OK?

I'm not confident with regenerating configure due to some unrelated
changes added, can someone else help with that?
From: Jonathan Yong <10wa...@gmail.com>
Date: Sun, 22 Mar 2020 01:59:37 + (+0800)
Subject: libstdc++: use a link test to test for -Wl,-z,relro
X-Git-Url: 
https://repo.or.cz/gcc/cygwin-gcc.git/commitdiff_plain/1b20e03e7468760828bfc70fc5e811b5b3738adf

libstdc++: use a link test to test for -Wl,-z,relro

Do a link test instead of just a grep. The linker can
support multiple targets, but not all targets can use it.

Signed-off-by: Jonathan Yong <10wa...@gmail.com>
---

diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index bc7d137dc74..209aa3a91f3 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -274,7 +274,16 @@ AC_DEFUN([GLIBCXX_CHECK_LINKER_FEATURES], [
   ac_ld_relro=no
   if test x"$with_gnu_ld" = x"yes"; then
 AC_MSG_CHECKING([for ld that supports -Wl,-z,relro])
-cxx_z_relo=`$LD -v --help 2>/dev/null | grep "z relro"`
+ac_save_ldflags="$LDFLAGS"
+LDFLAGS="$LDFLAGS -Wl,-z,relro"
+AC_LINK_IFELSE([
+  AC_LANG_SOURCE(
+[[int main() { return 0; }]]
+  )],
+  [cxx_z_relo="1"],
+  [cxx_z_relo=""])
+   LDFLAGS="$ac_save_ldflags"
+
 if test -n "$cxx_z_relo"; then
   OPT_LDFLAGS="-Wl,-z,relro"
   ac_ld_relro=yes


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