[Coverage] Report errors when reading malformed source regions

Each source region has a start and end location. Report an error when
the end location does not precede the begin location.

The old lineExecutionCounts.covmapping test actually had a buggy source
region in it. This commit introduces a regenerated copy of the coverage
and moves the old copy to malformedRegions.covmapping, for a test.

Differential Revision: https://reviews.llvm.org/D37387

llvm-svn: 312814

1 files changed, 7 insertions, 2 deletions

diff --git a/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp b/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
index 346ac76..d2878d3 100644
--- a/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
+++ b/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
@@ -250,10 +250,15 @@ Expected<std::unique_ptr<CoverageMapping>> CoverageMapping::load(
     IndexedInstrProfReader &ProfileReader) {
   auto Coverage = std::unique_ptr<CoverageMapping>(new CoverageMapping());
 
-  for (const auto &CoverageReader : CoverageReaders)
-    for (const auto &Record : *CoverageReader)
+  for (const auto &CoverageReader : CoverageReaders) {
+    for (auto RecordOrErr : *CoverageReader) {
+      if (Error E = RecordOrErr.takeError())
+        return std::move(E);
+      const auto &Record = *RecordOrErr;
       if (Error E = Coverage->loadFunctionRecord(Record, ProfileReader))
         return std::move(E);
+    }
+  }
 
   return std::move(Coverage);
 }