libstdc++/66030 fix codecvt exports for mingw32

The linker script assumes that std::mbstate_t has the name __mbstate_t
for linkage purposes, but that's not necessarily true. For mingw32
it's just a typedef for int, so the patterns don't match.

This adds a new mingw32-specific pattern for codecvt_byname's
constructors and destructors, and relaxes the patterns for
codecvt<charNN_t, char, mbstate_t> so they match __mbstate_t or int.

Tested x86_64-linux and powerpc64le-linux, committed to trunk.

I plan to commit this to trunk and gcc-5-branch soon.

On 06/08/2015 09:12 AM, Jonathan Wakely wrote:
> The linker script assumes that std::mbstate_t has the name __mbstate_t
> for linkage purposes, but that's not necessarily true. For mingw32
> it's just a typedef for int, so the patterns don't match.
>
> This adds a new mingw32-specific pattern for codecvt_byname's
> constructors and destructors, and relaxes the patterns for
> codecvt<charNN_t, char, mbstate_t> so they match __mbstate_t or int.

As a data point, in case other targets have a similar issue,
mbstate_t is a typedef for char* on AIX, and (based on my
old notes) typedef struct mbstate_t on HP-UX.

(It is a typedef struct __mbstate_t on Darwin and Solaris.)

Martin

On 08/06/15 09:59 -0600, Martin Sebor wrote:
>On 06/08/2015 09:12 AM, Jonathan Wakely wrote:
>>The linker script assumes that std::mbstate_t has the name __mbstate_t
>>for linkage purposes, but that's not necessarily true. For mingw32
>>it's just a typedef for int, so the patterns don't match.
>>
>>This adds a new mingw32-specific pattern for codecvt_byname's
>>constructors and destructors, and relaxes the patterns for
>>codecvt<charNN_t, char, mbstate_t> so they match __mbstate_t or int.
>
>As a data point, in case other targets have a similar issue,
>mbstate_t is a typedef for char* on AIX, and (based on my
>old notes) typedef struct mbstate_t on HP-UX.
>
>(It is a typedef struct __mbstate_t on Darwin and Solaris.)

That is useful, thanks.

AIX and HP-UX don't use that linker script, so it's not a problem (for
now) that it assumes __mbstate_t.

On 08/06/15 16:12 +0100, Jonathan Wakely wrote:
>The linker script assumes that std::mbstate_t has the name __mbstate_t
>for linkage purposes, but that's not necessarily true. For mingw32
>it's just a typedef for int, so the patterns don't match.
>
>This adds a new mingw32-specific pattern for codecvt_byname's
>constructors and destructors, and relaxes the patterns for
>codecvt<charNN_t, char, mbstate_t> so they match __mbstate_t or int.
>
>Tested x86_64-linux and powerpc64le-linux, committed to trunk.
>
>I plan to commit this to trunk and gcc-5-branch soon.

I've fully tested this on x86_64-linux and powerpc64le-linux, and also
manually verified there is no changed to the exported symbols on
Fedora 22 for i686, s390, s390x, ppc64, ppc64le, armv7hl and aarch64,
so am committing to the gcc-5-branch (approved by Jakub on IRC).


>commit dffce5e2b48ff19c4ec4de5d7ca934c15225b940
>Author: Jonathan Wakely <jwakely@redhat.com>
>Date:   Mon Jun 1 17:31:46 2015 +0100
>
>    	PR libstdc++/66030
>    	* config/abi/pre/gnu.ver: Export codecvt_byname and codecvt symbols
>    	for mingw32.
>
>diff --git a/libstdc++-v3/config/abi/pre/gnu.ver b/libstdc++-v3/config/abi/pre/gnu.ver
>index 2da04e4..d42cd37 100644
>--- a/libstdc++-v3/config/abi/pre/gnu.ver
>+++ b/libstdc++-v3/config/abi/pre/gnu.ver
>@@ -542,6 +542,9 @@ GLIBCXX_3.4 {
>     # std::codecvt_byname
>     _ZNSt14codecvt_bynameI[cw]c11__mbstate_tEC[12]EPKc[jmy];
>     _ZNSt14codecvt_bynameI[cw]c11__mbstate_tED*;
>+#if defined (_WIN32) && !defined (__CYGWIN__)
>+    _ZNSt14codecvt_bynameI[cw]ciE[CD]*;
>+#endif
> 
>     # std::collate
>     _ZNSt7collateI[cw]*;
>@@ -1821,9 +1824,9 @@ GLIBCXX_3.4.21 {
>     _ZNKSt8time_getI[cw]St19istreambuf_iteratorI[cw]St11char_traitsI[cw]EEE6do_getES3_S3_RSt8ios_baseRSt12_Ios_IostateP2tmcc;
> 
>     # codecvt<char16_t, char, mbstate_t>, codecvt<char32_t, char, mbstate_t>
>-    _ZNKSt7codecvtID[is]c11__mbstate_t*;
>-    _ZNSt7codecvtID[is]c11__mbstate_t*;
>-    _ZT[ISV]St7codecvtID[is]c11__mbstate_tE;
>+    _ZNKSt7codecvtID[is]c*;
>+    _ZNSt7codecvtID[is]c*;
>+    _ZT[ISV]St7codecvtID[is]c*E;
> 
>     extern "C++"
>     {