r360998 - Fix crash if, during evaluation of __builtin_object_size, we try to load

[Richard Smith via cfe-commits]

Author: rsmith
Date: Fri May 17 01:01:34 2019
New Revision: 360998

URL: http://llvm.org/viewvc/llvm-project?rev=360998&view=rev
Log:
Fix crash if, during evaluation of __builtin_object_size, we try to load
through an invalid base.

Modified:
    cfe/trunk/lib/AST/ExprConstant.cpp
    cfe/trunk/test/SemaCXX/builtin-object-size-cxx14.cpp

Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=360998&r1=360997&r2=360998&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Fri May 17 01:01:34 2019
@@ -3285,6 +3285,11 @@ static bool AreElementsOfSameArray(QualT
 static CompleteObject findCompleteObject(EvalInfo &Info, const Expr *E,
                                          AccessKinds AK, const LValue &LVal,
                                          QualType LValType) {
+  if (LVal.InvalidBase) {
+    Info.FFDiag(E);
+    return CompleteObject();
+  }
+
   if (!LVal.Base) {
     Info.FFDiag(E, diag::note_constexpr_access_null) << AK;
     return CompleteObject();

Modified: cfe/trunk/test/SemaCXX/builtin-object-size-cxx14.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/builtin-object-size-cxx14.cpp?rev=360998&r1=360997&r2=360998&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/builtin-object-size-cxx14.cpp (original)
+++ cfe/trunk/test/SemaCXX/builtin-object-size-cxx14.cpp Fri May 17 01:01:34 2019
@@ -97,3 +97,10 @@ void tooSmallBuf() {
   copy5CharsIntoStrict(small.buf); // expected-error{{no matching function for call}}
 }
 }
+
+namespace InvalidBase {
+  // Ensure this doesn't crash.
+  struct S { const char *name; };
+  S invalid_base();
+  constexpr long bos_name = __builtin_object_size(invalid_base().name, 1);
+}