[Coverage] Take filenames into account when loading function records.

Summary:
Don't skip functions with the same name but from different files.

That change makes it possible to generate code coverage reports from
different binaries compiled from different sources even if there are functions
with non-unique names. Without that change, code coverage for such functions is
missing except of the first function processed.

Reviewers: vsk, morehouse

Reviewed By: vsk

Subscribers: llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D46478

llvm-svn: 331801

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp b/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
index 921372b..ac0793d 100644
--- a/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
+++ b/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
@@ -207,8 +207,10 @@ Error CoverageMapping::loadFunctionRecord(
   else
     OrigFuncName = getFuncNameWithoutPrefix(OrigFuncName, Record.Filenames[0]);
 
-  // Don't load records for functions we've already seen.
-  if (!FunctionNames.insert(OrigFuncName).second)
+  // Don't load records for (filenames, function) pairs we've already seen.
+  auto FilenamesHash = hash_combine_range(Record.Filenames.begin(),
+                                          Record.Filenames.end());
+  if (!RecordProvenance[FilenamesHash].insert(hash_value(OrigFuncName)).second)
     return Error::success();
 
   CounterMappingContext Ctx(Record.Expressions);