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: 308327

1 files changed, 7 insertions, 2 deletions

diff --git a/clang/lib/Parse/ParsePragma.cpp b/clang/lib/Parse/ParsePragma.cpp
index 262743756a6..c5215ffceeb 100644
--- a/clang/lib/Parse/ParsePragma.cpp
+++ b/clang/lib/Parse/ParsePragma.cpp
@@ -422,15 +422,20 @@ void Parser::HandlePragmaPack() {
   assert(Tok.is(tok::annot_pragma_pack));
   PragmaPackInfo *Info =
     static_cast<PragmaPackInfo *>(Tok.getAnnotationValue());
-  SourceLocation PragmaLoc = ConsumeAnnotationToken();
+  SourceLocation PragmaLoc = Tok.getLocation();
   ExprResult Alignment;
   if (Info->Alignment.is(tok::numeric_constant)) {
     Alignment = Actions.ActOnNumericConstant(Info->Alignment);
-    if (Alignment.isInvalid())
+    if (Alignment.isInvalid()) {
+      ConsumeAnnotationToken();
       return;
+    }
   }
   Actions.ActOnPragmaPack(PragmaLoc, Info->Action, Info->SlotLabel,
                           Alignment.get());
+  // Consume the token after processing the pragma to enable pragma-specific
+  // #include warnings.
+  ConsumeAnnotationToken();
 }
 
 void Parser::HandlePragmaMSStruct() {