Takumi provides some more details on IRC: The change broke http://bb.pgr.jp/builders/bootstrap-clang-libcxx-lld-i686-linux/builds/655/steps/build_stage2/logs/stdio , which uses modules. He says there's a race-condition: while clang emits ***-{tmp}.pcm, another clang collects *.pcm for the module index. GlobalModuleIndex.cpp walks over a directory here and ignores everything not ending in '.pcm' here: http://llvm-cs.pcc.me.uk/tools/clang/lib/Serialization/GlobalModuleIndex.cpp#850
That seems pretty gross, but I can't think of a non-gross way to make this patch work with that pcm walking. We could always append ".tmp" to the temp file names, but then the original benefit is gone too. We could do this patch only for .obj files, or always except for .pcm files, but that seems both kind of gross as well. On Fri, Aug 4, 2017 at 2:35 AM, NAKAMURA Takumi via cfe-commits < cfe-commits@lists.llvm.org> wrote: > Author: chapuni > Date: Thu Aug 3 23:35:32 2017 > New Revision: 310030 > > URL: http://llvm.org/viewvc/llvm-project?rev=310030&view=rev > Log: > Revert r309984, "Use "foo-12345.o" instead of "foo.o-12345" as temporary > file name." > > It generates MODULE-XXXXXXXXXXXX-%%%%%%%%.pcm, then GlobalModuleIndex.cpp > is confused with the suffix ".pcm" > > Modified: > cfe/trunk/lib/Frontend/CompilerInstance.cpp > > Modified: cfe/trunk/lib/Frontend/CompilerInstance.cpp > URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/ > Frontend/CompilerInstance.cpp?rev=310030&r1=310029&r2=310030&view=diff > ============================================================ > ================== > --- cfe/trunk/lib/Frontend/CompilerInstance.cpp (original) > +++ cfe/trunk/lib/Frontend/CompilerInstance.cpp Thu Aug 3 23:35:32 2017 > @@ -759,13 +759,9 @@ std::unique_ptr<llvm::raw_pwrite_stream> > > if (UseTemporary) { > // Create a temporary file. > - // Insert -%%%%%%%% before the extension (if any), so that tools doing > - // things based on the file extension do the right thing. > - StringRef OutputExtension = llvm::sys::path::extension(OutFile); > - SmallString<128> TempPath = > - StringRef(OutFile).drop_back(OutputExtension.size()); > + SmallString<128> TempPath; > + TempPath = OutFile; > TempPath += "-%%%%%%%%"; > - TempPath += OutputExtension; > int fd; > std::error_code EC = > llvm::sys::fs::createUniqueFile(TempPath, fd, TempPath); > > > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >
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