diagnose extended uses of offsetof
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@41653 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Sema/SemaExpr.cpp b/Sema/SemaExpr.cpp
index 3b65ab2..daddb50 100644
--- a/Sema/SemaExpr.cpp
+++ b/Sema/SemaExpr.cpp
@@ -1743,6 +1743,12 @@
// iteratively process the offsetof designators.
Expr *Res = new CompoundLiteralExpr(ArgTy, 0);
+ // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a
+ // GCC extension, diagnose them.
+ if (NumComponents != 1)
+ Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator,
+ SourceRange(CompPtr[1].LocStart, CompPtr[NumComponents-1].LocEnd));
+
for (unsigned i = 0; i != NumComponents; ++i) {
const OffsetOfComponent &OC = CompPtr[i];
if (OC.isBrackets) {