[PATCH] D70615: Add an -fno-temp-file flag for compilation

[Zachary Henkel via Phabricator via cfe-commits]

zahen added a comment.

In our build system every file access in an "output directory" needs to be accounted for.  Until this patch, the random temporary file name has forced us to rely on workarounds that hurt build throughput.

I've uploaded example ProcMon dumps of clang-cl.exe file accesses to help illustrate what the patch is trying to achieve.  In the RTM log, clang-cl creates a file ConsoleApplication1-dc91d1ce.obj.tmp directly in the output directory, writes the contents and ends by calling SetRenameInformationFile to "create" the final ConsoleApplication1.obj.  In the patched log the file ConsoleApplication1.obj is created and written to directly.

F11003490: clang9.0-RTM.CSV <https://reviews.llvm.org/F11003490>
F11003493: clang9.0-patched.CSV <https://reviews.llvm.org/F11003493>


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  https://reviews.llvm.org/D70615/new/

https://reviews.llvm.org/D70615