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

[Zequan Wu via Phabricator via cfe-commits]

zequanwu updated this revision to Diff 512971.
zequanwu edited the summary of this revision.
zequanwu added a comment.

- Filed an github issue:
- Added release note.
- Updated commit message and summary.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D147073/new/

https://reviews.llvm.org/D147073

Files:
  clang/docs/ReleaseNotes.rst
  clang/lib/CodeGen/CoverageMappingGen.cpp


Index: clang/lib/CodeGen/CoverageMappingGen.cpp
===================================================================
--- clang/lib/CodeGen/CoverageMappingGen.cpp
+++ clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -602,6 +602,19 @@
       MostRecentLocation = *StartLoc;
     }
 
+    // If either of these locations is invalid, something elsewhere in the
+    // compiler has broken.
+    assert((!StartLoc || StartLoc->isValid()) && "Start location is not valid");
+    assert((!EndLoc || EndLoc->isValid()) && "End location is not valid");
+
+    // However, we can still recover without crashing.
+    // If 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 +637,8 @@
     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 +705,7 @@
         assert(SM.isWrittenInSameFile(Region.getBeginLoc(), EndLoc));
         assert(SpellingRegion(SM, Region).isInSourceOrder());
         SourceRegions.push_back(Region);
-        }
+      }
       RegionStack.pop_back();
     }
   }
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -248,6 +248,10 @@
 - Fix false-positive diagnostic issued for consteval initializers of temporary
   objects.
   (`#60286 <https://github.com/llvm/llvm-project/issues/60286>`_)
+- Work around with a clang coverage crash which happens when visiting 
+  expressions/statements with invalid source locations in non-assert builds. 
+  Assert builds may still see assertions triggered from this.
+  (`#62105 <https://github.com/llvm/llvm-project/issues/62105>`_)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


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