[Sema] Diagnose default-initialization, destruction, and copying of

non-trivial C union types

This patch diagnoses uses of non-trivial C unions and structs/unions
containing non-trivial C unions in the following contexts, which require
default-initialization, destruction, or copying of the union objects,
instead of disallowing fields of non-trivial types in C unions, which is
what we currently do:

- function parameters.
- function returns.
- assignments.
- compound literals.
- block captures except capturing of `__block` variables by non-escaping
  blocks.
- local and global variable definitions.
- lvalue-to-rvalue conversions of volatile types.

See the discussion in https://reviews.llvm.org/D62988 for more background.

rdar://problem/50679094

Differential Revision: https://reviews.llvm.org/D63753

llvm-svn: 365985

1 files changed, 0 insertions, 10 deletions

diff --git a/clang/test/CodeGenObjC/Inputs/strong_in_union.h b/clang/test/CodeGenObjC/Inputs/strong_in_union.h
deleted file mode 100644
index abe4549055c..00000000000
--- a/clang/test/CodeGenObjC/Inputs/strong_in_union.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#ifndef STRONG_IN_UNION_H
-#define STRONG_IN_UNION_H
-#pragma clang system_header
-
-typedef union {
-  id f0;
-  int *f1;
-} U;
-
-#endif // STRONG_IN_UNION_H