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
llvm-svn: 309386
diff --git a/clang/test/Sema/suspicious-pragma-pack.c b/clang/test/Sema/suspicious-pragma-pack.c
new file mode 100644
index 0000000..d7c5faf
--- /dev/null
+++ b/clang/test/Sema/suspicious-pragma-pack.c
@@ -0,0 +1,50 @@
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -I %S/Inputs -DSAFE -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -I %S/Inputs -DPUSH_HERE -DSAFE -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -I %S/Inputs -DPUSH_HERE -DPUSH_SET_HERE -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -I %S/Inputs -DPUSH_HERE -DRESET_HERE -DSAFE -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -I %S/Inputs -DPUSH_HERE -DSET_FIRST_HEADER -DWARN_MODIFIED_HEADER -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -I %S/Inputs -DPUSH_HERE -DRESET_HERE -DSET_FIRST_HEADER -DWARN_MODIFIED_HEADER -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -I %S/Inputs -DPUSH_HERE -DPUSH_SET_HERE -DSET_FIRST_HEADER -DWARN_MODIFIED_HEADER -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -I %S/Inputs -DPUSH_HERE -DPUSH_SET_HERE -DSET_SECOND_HEADER -DWARN_MODIFIED_HEADER -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -I %S/Inputs -DPUSH_HERE -DPUSH_SET_HERE -DSET_FIRST_HEADER -DSET_SECOND_HEADER -DWARN_MODIFIED_HEADER -verify %s
+
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -I %S/Inputs -DPUSH_POP_FIRST_HEADER -DSAFE -verify %s
+
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -I %S/Inputs -DPUSH_SET_HERE -DNO_RECORD_1 -DNO_RECORD_2 -DSAFE -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack-suspicious-include -I %S/Inputs -DPUSH_SET_HERE -DNO_RECORD_1 -verify %s
+// RUN: %clang_cc1 -triple i686-apple-darwin9 -fsyntax-only -Wpragma-pack -Wno-pragma-pack-suspicious-include -I %S/Inputs -DPUSH_SET_HERE -DNO_RECORD_1 -DSAFE -verify %s
+
+#ifdef SAFE
+// expected-no-diagnostics
+#endif
+
+#ifdef PUSH_HERE
+#pragma pack (push)
+#endif
+
+#ifdef PUSH_SET_HERE
+#pragma pack (push, 4)
+#ifndef SAFE
+// expected-note@-2 {{previous '#pragma pack' directive that modifies alignment is here}}
+// expected-warning@+9 {{non-default #pragma pack value changes the alignment of struct or union members in the included file}}
+#endif
+#endif
+
+#ifdef RESET_HERE
+#pragma pack (4)
+#pragma pack () // no warning after reset as the value is default.
+#endif
+
+#include "pragma-pack1.h"
+
+#ifdef WARN_MODIFIED_HEADER
+// expected-warning@-3 {{the current #pragma pack aligment value is modified in the included file}}
+#endif
+
+#ifdef PUSH_SET_HERE
+#pragma pack (pop)
+#endif
+
+#ifdef PUSH_HERE
+#pragma pack (pop)
+#endif