[PATCH] D147073: [Coverage] Handle invalid end location of an expression/statement.

[Zequan Wu via Phabricator via cfe-commits]

zequanwu created this revision.
zequanwu added reviewers: hans, shafik, rsmith, MaggieYi, gulfem.
Herald added a project: All.
zequanwu requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

https://github.com/llvm/llvm-project/issues/45481 exposes an issue that an
expression/statement can have valid start location but invalid end location in
some situations.

This confuses `CounterCoverageMappingBuilder` when popping a region from region
stack as if the end location is a macro or include location.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D147073

Files:
  clang/lib/CodeGen/CoverageMappingGen.cpp


Index: clang/lib/CodeGen/CoverageMappingGen.cpp
===================================================================
--- clang/lib/CodeGen/CoverageMappingGen.cpp
+++ clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -602,6 +602,13 @@
       MostRecentLocation = *StartLoc;
     }
 
+    // If the either location is invalid, set it to std::nullopt to avoid
+    // letting users of RegionStack think that region has a valid start/end
+    // location.
+    if (StartLoc && StartLoc->isInvalid())
+      StartLoc = std::nullopt;
+    if (EndLoc && EndLoc->isInvalid())
+      EndLoc = std::nullopt;
     RegionStack.emplace_back(Count, FalseCount, StartLoc, EndLoc);
 
     return RegionStack.size() - 1;
@@ -624,7 +631,8 @@
     assert(RegionStack.size() >= ParentIndex && "parent not in stack");
     while (RegionStack.size() > ParentIndex) {
       SourceMappingRegion &Region = RegionStack.back();
-      if (Region.hasStartLoc()) {
+      if (Region.hasStartLoc() &&
+          (Region.hasEndLoc() || RegionStack[ParentIndex].hasEndLoc())) {
         SourceLocation StartLoc = Region.getBeginLoc();
         SourceLocation EndLoc = Region.hasEndLoc()
                                     ? Region.getEndLoc()
@@ -691,7 +699,7 @@
         assert(SM.isWrittenInSameFile(Region.getBeginLoc(), EndLoc));
         assert(SpellingRegion(SM, Region).isInSourceOrder());
         SourceRegions.push_back(Region);
-        }
+      }
       RegionStack.pop_back();
     }
   }


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