Merge pull request #877 from apple/59919733-cherry-pick

[Sema] Fix a crash when attaching comments to an implicit decl
llvm · Mar 6, 2020 · e6ce0dd · e6ce0dd
2 parents 2c1df94 + 08c4a41
commit e6ce0dd
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Showing 2 changed files with 22 additions and 4 deletions.
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
@@ -494,10 +494,20 @@ void ASTContext::attachCommentsToJustParsedDecls(ArrayRef<Decl *> Decls,
   if (Comments.empty() || Decls.empty())
     return;
 
-  // See if there are any new comments that are not attached to a decl.
-  // The location doesn't have to be precise - we care only about the file.
-  const FileID File =
-      SourceMgr.getDecomposedLoc((*Decls.begin())->getLocation()).first;
+  FileID File;
+  for (Decl *D : Decls) {
+    SourceLocation Loc = D->getLocation();
+    if (Loc.isValid()) {
+      // See if there are any new comments that are not attached to a decl.
+      // The location doesn't have to be precise - we care only about the file.
+      File = SourceMgr.getDecomposedLoc(Loc).first;
+      break;
+    }
+  }
+
+  if (File.isInvalid())
+    return;
+
   auto CommentsInThisFile = Comments.getCommentsInFile(File);
   if (!CommentsInThisFile || CommentsInThisFile->empty() ||
       CommentsInThisFile->rbegin()->second->isAttached())

diff --git a/clang/test/Sema/warn-documentation.m b/clang/test/Sema/warn-documentation.m
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -fsyntax-only -fblocks -Wno-objc-root-class -Wdocumentation -Wdocumentation-pedantic -verify %s
+// RUN: %clang_cc1 -xobjective-c++ -fsyntax-only -fblocks -Wno-objc-root-class -Wdocumentation -Wdocumentation-pedantic -verify %s
 
 @class NSString;
 
@@ -318,3 +319,10 @@ @interface CheckFunctionBlockPointerVars {
 // expected-warning@-1 {{'\return' command used in a comment that is not attached to a function or method declaration}}
 VoidBlockTypeCall ^e; ///< \return none
 // expected-warning@-1 {{'\return' command used in a comment that is not attached to a function or method declaration}}
+
+#ifdef __cplusplus
+@interface HasAnonNamespace @end
+@implementation HasAnonNamespace
+namespace {}
+@end
+#endif