objectiveC blocks: It is impractical to capture

struct variables with flexiable array members in
blocks (and lambdas). Issue error instead of
crashing in IRGen. // rdar://12655829


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171912 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 16 insertions, 1 deletions

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 1704de6e95..b5630ecb12 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -10759,7 +10759,22 @@ bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation Loc,
       }
       return true;
     }
-
+    // Prohibit prohibit structs with flexisble array members too.
+    // We cannot capture what is in the tail end of the struct.
+    if (const RecordType *VTTy = Var->getType()->getAs<RecordType>()) {
+      if (VTTy->getDecl()->hasFlexibleArrayMember()) {
+        if (BuildAndDiagnose) {
+          if (IsBlock)
+            Diag(Loc, diag::err_ref_flexarray_type);
+          else
+            Diag(Loc, diag::err_lambda_capture_flexarray_type)
+              << Var->getDeclName();
+          Diag(Var->getLocation(), diag::note_previous_decl)
+            << Var->getDeclName();
+        }
+        return true;
+      }
+    }
     // Lambdas are not allowed to capture __block variables; they don't
     // support the expected semantics.
     if (IsLambda && HasBlocksAttr) {