Recommit r308327 2nd time: Add a warning for missing

'#pragma pack (pop)' and suspicious uses of '#pragma pack' in included files

The first recommit (r308441) caused a "non-default #pragma pack value might
change the alignment of struct or union members in the included file" warning
in LLVM itself. This recommit tweaks the added warning to avoid warnings for
#includes that don't have any records that are affected by the non-default
alignment. This tweak avoids the previously emitted warning in LLVM.

Original message:

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


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@309106 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 1 deletions

diff --git a/include/clang/Basic/DiagnosticGroups.td b/include/clang/Basic/DiagnosticGroups.td
index 2927315ff0..2177067fc5 100644
--- a/include/clang/Basic/DiagnosticGroups.td
+++ b/include/clang/Basic/DiagnosticGroups.td
@@ -471,8 +471,9 @@ def IgnoredPragmaIntrinsic : DiagGroup<"ignored-pragma-intrinsic">;
 def UnknownPragmas : DiagGroup<"unknown-pragmas">;
 def IgnoredPragmas : DiagGroup<"ignored-pragmas", [IgnoredPragmaIntrinsic]>;
 def PragmaClangAttribute : DiagGroup<"pragma-clang-attribute">;
+def PragmaPack : DiagGroup<"pragma-pack">;
 def Pragmas : DiagGroup<"pragmas", [UnknownPragmas, IgnoredPragmas,
-                                    PragmaClangAttribute]>;
+                                    PragmaClangAttribute, PragmaPack]>;
 def UnknownWarningOption : DiagGroup<"unknown-warning-option">;
 def NSobjectAttribute : DiagGroup<"NSObject-attribute">;
 def IndependentClassAttribute : DiagGroup<"IndependentClass-attribute">;