That's an interesting case. I'll tweak the warning to diagnose this scenario better today.
On 29 July 2017 at 00:56, Hans Wennborg <h...@chromium.org> wrote: > On Fri, Jul 28, 2017 at 7:41 AM, Alex Lorenz via cfe-commits > <cfe-commits@lists.llvm.org> wrote: > > Author: arphaman > > Date: Fri Jul 28 07:41:21 2017 > > New Revision: 309386 > > > > URL: http://llvm.org/viewvc/llvm-project?rev=309386&view=rev > > Log: > > Recommit r308327 3rd time: Add a warning for missing > > '#pragma pack (pop)' and suspicious uses of '#pragma pack' in included > files > > > > The second recommit (r309106) was reverted because the "non-default > #pragma > > pack value chages the alignment of struct or union members in the > included file" > > warning proved to be too aggressive for external projects like Chromium > > (https://bugs.chromium.org/p/chromium/issues/detail?id=749197). This > recommit > > makes the problematic warning a non-default one, and gives it the > > -Wpragma-pack-suspicious-include warning option. > > > > The first recommit (r308441) caused a "non-default #pragma pack value > might > > change the alignment of struct or union members in the included file" > warning > > in LLVM itself. This recommit tweaks the added warning to avoid warnings > for > > #includes that don't have any records that are affected by the > non-default > > alignment. This tweak avoids the previously emitted warning in LLVM. > > > > Original message: > > > > This commit adds a new -Wpragma-pack warning. It warns in the following > cases: > > > > - When a translation unit is missing terminating #pragma pack (pop) > directives. > > - When entering an included file if the current alignment value as > determined > > by '#pragma pack' directives is different from the default alignment > value. > > - When leaving an included file that changed the state of the current > alignment > > value. > > > > rdar://10184173 > > > > Differential Revision: https://reviews.llvm.org/D35484 > > We did get warnings with this version too, but this time it looks like > a real bug :-) > > C:\b\c\builder\ClangToTWin_dll_\src\third_party\usrsctp\ > usrsctplib\usrsctplib\netinet\sctp.h(51,9): > error: unterminated '#pragma pack (push, ...)' at end of file > [-Werror,-Wpragma-pack] > > The interesting thing is that the file does reset the alignment, but > it does it with a "#pragma pack()" which doesn't pop the stack, but > just resets to the default value. > > It might be worth tweaking the warning to give a better message for > this. A "#pragma pack(push, ..)" followed by "#pragma pack()" seems > pretty dodgy since there's no point in pushing if the code isn't going > to pop. >
_______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
