Recommit r308327 3rd time: Add a warning for missing

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

The second recommit (r309106) was reverted because the "non-default #pragma
pack value chages the alignment of struct or union members in the included file"
warning proved to be too aggressive for external projects like Chromium
(https://bugs.chromium.org/p/chromium/issues/detail?id=749197). This recommit
makes the problematic warning a non-default one, and gives it the
-Wpragma-pack-suspicious-include warning option.

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@309386 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 23 insertions, 15 deletions

diff --git a/test/PCH/pragma-pack.c b/test/PCH/pragma-pack.c
index 47a5570023..7b45e045b3 100644
--- a/test/PCH/pragma-pack.c
+++ b/test/PCH/pragma-pack.c
@@ -1,21 +1,21 @@
 // Test this without pch.
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -DSET
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -DRESET
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -DPUSH
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -DPUSH_POP
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -DPUSH_POP_LABEL
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -Wno-pragma-pack -DSET
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -Wno-pragma-pack -DRESET
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -Wno-pragma-pack -DPUSH
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -Wno-pragma-pack -DPUSH_POP
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -include %s -verify -fsyntax-only -Wno-pragma-pack -DPUSH_POP_LABEL
 
 // Test with pch.
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DSET -emit-pch -o %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DSET -verify -include-pch %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DRESET -emit-pch -o %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DRESET -verify -include-pch %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH -emit-pch -o %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH -verify -include-pch %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH_POP -emit-pch -o %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH_POP -verify -include-pch %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH_POP_LABEL -emit-pch -o %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -DPUSH_POP_LABEL -verify -include-pch %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DSET -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DSET -verify -include-pch %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DRESET -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DRESET -verify -include-pch %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH -verify -include-pch %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH_POP -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH_POP -verify -include-pch %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH_POP_LABEL -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -Wno-pragma-pack -DPUSH_POP_LABEL -verify -include-pch %t
 
 #ifndef HEADER
 #define HEADER
diff --git a/test/PCH/suspicious-pragma-pack.c b/test/PCH/suspicious-pragma-pack.c
new file mode 100644
index 0000000000..01a66af34b
--- /dev/null
+++ b/test/PCH/suspicious-pragma-pack.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -verify -emit-pch -o %t
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -verify -include-pch %t
+
+#ifndef HEADER
+#define HEADER
+#pragma pack (push, 1)
+#endif
+// expected-warning@-2 {{unterminated '#pragma pack (push, ...)' at end of file}}