[Coverage] Combine counts of expansion regions if there are no code regions for the same area.
Differential Revision: http://reviews.llvm.org/D18831
llvm-svn: 268620
diff --git a/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp b/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
index 5d86f1d..9fdd370 100644
--- a/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
+++ b/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
@@ -334,13 +334,25 @@
/// Sort a nested sequence of regions from a single file.
static void sortNestedRegions(MutableArrayRef<CountedRegion> Regions) {
- std::sort(Regions.begin(), Regions.end(),
- [](const CountedRegion &LHS, const CountedRegion &RHS) {
- if (LHS.startLoc() == RHS.startLoc())
- // When LHS completely contains RHS, we sort LHS first.
- return RHS.endLoc() < LHS.endLoc();
- return LHS.startLoc() < RHS.startLoc();
- });
+ std::sort(Regions.begin(), Regions.end(), [](const CountedRegion &LHS,
+ const CountedRegion &RHS) {
+ if (LHS.startLoc() != RHS.startLoc())
+ return LHS.startLoc() < RHS.startLoc();
+ if (LHS.endLoc() != RHS.endLoc())
+ // When LHS completely contains RHS, we sort LHS first.
+ return RHS.endLoc() < LHS.endLoc();
+ // If LHS and RHS cover the same area, we need to sort them according
+ // to their kinds so that the most suitable region will become "active"
+ // in combineRegions(). Because we accumulate counter values only from
+ // regions of the same kind as the first region of the area, prefer
+ // CodeRegion to ExpansionRegion and ExpansionRegion to SkippedRegion.
+ static_assert(coverage::CounterMappingRegion::CodeRegion <
+ coverage::CounterMappingRegion::ExpansionRegion &&
+ coverage::CounterMappingRegion::ExpansionRegion <
+ coverage::CounterMappingRegion::SkippedRegion,
+ "Unexpected order of region kind values");
+ return LHS.Kind < RHS.Kind;
+ });
}
/// Combine counts of regions which cover the same area.
@@ -360,15 +372,18 @@
continue;
}
// Merge duplicate region.
- if (I->Kind != coverage::CounterMappingRegion::CodeRegion)
- // Add counts only from CodeRegions.
- continue;
- if (Active->Kind == coverage::CounterMappingRegion::SkippedRegion)
- // We have to overwrite SkippedRegions because of special handling
- // of them in startSegment().
- *Active = *I;
- else
- // Otherwise, just append the count.
+ // If CodeRegions and ExpansionRegions cover the same area, it's probably
+ // a macro which is fully expanded to another macro. In that case, we need
+ // to accumulate counts only from CodeRegions, or else the area will be
+ // counted twice.
+ // On the other hand, a macro may have a nested macro in its body. If the
+ // outer macro is used several times, the ExpansionRegion for the nested
+ // macro will also be added several times. These ExpansionRegions cover
+ // the same source locations and have to be combined to reach the correct
+ // value for that area.
+ // We add counts of the regions of the same kind as the active region
+ // to handle the both situations.
+ if (I->Kind == Active->Kind)
Active->ExecutionCount += I->ExecutionCount;
}
return Regions.drop_back(std::distance(++Active, End));