Gerald,
this documents the fix for pr87137. Discovered as a GCC-8 regression,
turned out to be an ABI bug. Decided to fix the entire bug in one go.
Are these changes.html changes ok?
Patch discussion at https://gcc.gnu.org/ml/gcc-patches/2018-08/msg01900.html
nathan
--
Nathan Sidwell
Index: gcc-8/changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-8/changes.html,v
retrieving revision 1.94
diff -r1.94 changes.html
1351a1352,1377
> <!-- .................................................................. -->
> <h2 id="GCC8.3">GCC 8.3</h2>
>
> GCC 8.3 is <em>not</em> yet released.
>
> <h3>Windows</h3>
>
> <ul>
> <li>A C++ Microsoft ABI bitfield layout
> bug, <a href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87137";>PR87137</a>
> has been fixed. A non-field declaration could cause the current
> bitfield allocation unit to be completed, incorrectly placing a
> following bitfield into a new allocation unit. Microsoft ABI is
> selected for:
> <ul>
> <li>Mingw targets
> <li>PowerPC, IA-32 or x86-64 targets
> when <code>-mms-bitfields</code> option is specified
> or <code>__attribute__((ms_struct))</code> is used
> <li>SuperH targets when the <code>-mhitachi</code> option is
> specified, or <code>__attribute__((renesas))</code> is used
> </ul>
> GCC 8 introduced additional cases of this defect, but rather than
> resolve only those regressions, it was decided to resolve all the
> case of this defect at once.
>
Index: gcc-9/changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-9/changes.html,v
retrieving revision 1.19
diff -r1.19 changes.html
212c212
< <!-- <h3 id="windows">Windows</h3> -->
---
> <h3 id="windows">Windows</h3>
213a214,228
> <ul>
> <li>A C++ Microsoft ABI bitfield layout
> bug, <a href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87137";>PR87137</a>
> has been fixed. A non-field declaration could cause the current
> bitfield allocation unit to be completed, incorrectly placing a
> following bitfield into a new allocation unit. Microsoft ABI is
> selected for:
> <ul>
> <li>Mingw targets
> <li>PowerPC, IA-32 or x86-64 targets
> when <code>-mms-bitfields</code> option is specified
> or <code>__attribute__((ms_struct))</code> is used
> <li>SuperH targets when the <code>-mhitachi</code> option is
> specified, or <code>__attribute__((renesas))</code> is used
> </ul>
