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

3 files changed, 3 insertions, 3 deletions

diff --git a/test/Parser/pragma-options.c b/test/Parser/pragma-options.c
index d168a2751a..a35f0b087e 100644
--- a/test/Parser/pragma-options.c
+++ b/test/Parser/pragma-options.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple i386-apple-darwin9 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -Wno-pragma-pack -fsyntax-only -verify %s
 
 /* expected-warning {{expected 'align' following '#pragma options'}} */ #pragma options
 /* expected-warning {{expected '=' following '#pragma options align'}} */ #pragma options align
diff --git a/test/Parser/pragma-options.cpp b/test/Parser/pragma-options.cpp
index 84cd38dfb3..8f5a2152c7 100644
--- a/test/Parser/pragma-options.cpp
+++ b/test/Parser/pragma-options.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple i386-apple-darwin9 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -Wno-pragma-pack -fsyntax-only -verify %s
 // expected-no-diagnostics
 
 class C {
diff --git a/test/Parser/pragma-pack.c b/test/Parser/pragma-pack.c
index 0859f4157c..d2aefaa888 100644
--- a/test/Parser/pragma-pack.c
+++ b/test/Parser/pragma-pack.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wno-pragma-pack -verify %s
 
 // Note that this puts the expected lines before the directives to work around
 // limitations in the -verify mode.