Recommit r308327: Add a warning for missing '#pragma pack (pop)'

and suspicious uses of '#pragma pack' in included files

This commit adds a new -Wpragma-pack warning. It warns in the following cases:

- When a translation unit is missing terminating #pragma pack (pop) directives.
- When entering an included file if the current alignment value as determined
  by '#pragma pack' directives is different from the default alignment value.
- When leaving an included file that changed the state of the current alignment
  value.

rdar://10184173

Differential Revision: https://reviews.llvm.org/D35484

llvm-svn: 308441

1 files changed, 5 insertions, 0 deletions

diff --git a/clang/test/Sema/pragma-pack.c b/clang/test/Sema/pragma-pack.c
index e93ce42148c..84a946368ff 100644
--- a/clang/test/Sema/pragma-pack.c
+++ b/clang/test/Sema/pragma-pack.c
@@ -25,3 +25,8 @@
 #pragma pack(pop, 16)
 /* expected-warning {{value of #pragma pack(show) == 16}} */ #pragma pack(show)
 
+
+// Warn about unbalanced pushes.
+#pragma pack (push,4) // expected-warning {{unterminated '#pragma pack (push, ...)' at end of file}}
+#pragma pack (push)   // expected-warning {{unterminated '#pragma pack (push, ...)' at end of file}}
+#pragma pack ()