[PATCH] D62623: Reduce memory consumption of coverage dumps

[Vedant Kumar via Phabricator via cfe-commits]

vsk accepted this revision.
vsk added a comment.
This revision is now accepted and ready to land.

LGTM.



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Comment at: clang/lib/CodeGen/CoverageMappingGen.cpp:1393
+  size_t CoverageMappingSize = 0;
+  for (auto &S : CoverageMappings) {
+    CoverageMappingSize += S.size();
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serge-sans-paille wrote:
> vsk wrote:
> > It doesn't look like the CoverageMappings std::vector is needed at all. Consider moving `FilenamesAndCoverageMappings` into CoverageMappingModuleGen?
> > 
> > That should reduce the memory requirements a bit more.
> It's not possible to directly store into `FilenamesAndCoverageMappings` because filenames need to be stored before all mappings. It's possible to use a `std::string` instead of a `std::vector` but it means that at some point, memory usage will be `| CoverageMappings| x 2` while if we empty the vector elements as we push them to the stream, we should keep `|CoverageMappings|`. I've updated the diff to enforce this stream behavior.
Ah, thanks for explaining.


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  https://reviews.llvm.org/D62623/new/

https://reviews.llvm.org/D62623