Suppress -Warray-bounds for classes (not just structs) where the last field is

a 1-length character array.

llvm-svn: 145445

2 files changed, 18 insertions, 6 deletions

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 9dd03133b99..ec36963ed61 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -4202,8 +4202,11 @@ static bool IsTailPaddedMemberArray(Sema &S, llvm::APInt Size,
     return false;
 
   const RecordDecl *RD = dyn_cast<RecordDecl>(FD->getDeclContext());
-  if (!RD || !RD->isStruct())
-    return false;
+  if (!RD) return false;
+  if (RD->isUnion()) return false;
+  if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) {
+    if (!CRD->isStandardLayout()) return false;
+  }
 
   // See if this is the last field decl in the record.
   const Decl *D = FD;
diff --git a/clang/test/SemaCXX/array-bounds.cpp b/clang/test/SemaCXX/array-bounds.cpp
index 48788f67d74..c1b37011727 100644
--- a/clang/test/SemaCXX/array-bounds.cpp
+++ b/clang/test/SemaCXX/array-bounds.cpp
@@ -190,10 +190,19 @@ namespace tailpad {
     int x;
     char c2[1];
   };
-  
-  char bar(struct foo *F) {
-    return F->c1[3]; // expected-warning {{array index 3 is past the end of the array (which contains 1 element)}}
-    return F->c2[3]; // no warning, foo could have tail padding allocated.
+
+  class baz {
+   public:
+    char c1[1]; // expected-note {{declared here}}
+    int x;
+    char c2[1];
+  };
+
+  char bar(struct foo *F, baz *B) {
+    return F->c1[3] + // expected-warning {{array index 3 is past the end of the array (which contains 1 element)}}
+           F->c2[3] + // no warning, foo could have tail padding allocated.
+           B->c1[3] + // expected-warning {{array index 3 is past the end of the array (which contains 1 element)}}
+           B->c2[3]; // no warning, baz could have tail padding allocated.
   }
 }