On 4 December 2017 at 23:57, Dylan Baker <dy...@pnwbakers.com> wrote: > Quoting Emil Velikov (2017-11-23 11:04:34) >> On 20 November 2017 at 23:12, Dylan Baker <dy...@pnwbakers.com> wrote: >> > This doesn't actually accomplish what it's meant to do, as extern C >> > doesn't undefine __cplusplus, so the included headers define a template >> > (because __cplusplus is defined), but then that code is in an 'extern >> > "C"' block, and explosion. >> > >> The commit does sound a bit off, admittedly I don't fully grok what >> you're trying to say. >> >> The extern "C" { } construct annotates anything within as if it were a >> normal C code. Thus functions will have the C linkage (otherwise >> they'll have the C++ mangling) and structs are using the C rules. >> So if you have a C++ header further down the chain it will be >> considered as C and hell will break loose. >> >> This patch is correct, just sent a fix for glapitable.h, while glapi.h >> was handled with d38839a498b38b745f5bdf6b96fbafa2792670be. >> >> As-is "struct _glapi_table" will be interpret as C++ one, which may >> not have the same guarantees about sizeof and pointer arithmetic that >> we're using in the test. >> >> Hope the above provides some inspiration towards a better commit message. >> >> Thanks >> Emil > > So here's the problem I run into: > > In file included from ../include/c99_compat.h:28:0, > from ../src/util/macros.h:29, > from ../src/mapi/glapi/glapi.h:47, > from ../src/mapi/glapi/tests/check_table.cpp:28: > ../include/no_extern_c.h:47:1: error: template with C linkage > template<class T> class _IncludeInsideExternCNotPortable; > ^~~~~~~~ > [54/93] Compiling C++ object 'src/gtest/gtest@sta/src_gtest-all.cc.o'. > > So, my commit message still makes sense to me, since you can't put a template > in > an extern "C" block, and that template is guarded by __cplusplus, which is > still > defined even in an extern "C" block. > This is one symptom, of the issue described before. The code in c99_compat.h was explicitly added by Jose to make the issue obvious.
> Do you have a commit message in mind that is better? Feel free to reuse as much or as little of my explanation. Borrowing from analogous fixes also works ;-) Some examples: 237dcb4aa7c39c59bfd225ae3d73caf709be216d a177a13033cf9356eb26e8757055037a54268a18 36ad8265489fc66ab45b9b74dafa353a93bdb03b I'm going through 4/8 - seems like there's a bunch of other bugs around :-\ Feel free to push the remainder of the series with the nitpicks addressed. Thanks Emil _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev