Add support for attribute((mode(unwind_word))).

Patch by Nick Lewycky. Fixes pr8703.

llvm-svn: 171781

3 files changed, 9 insertions, 0 deletions

diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
index fbf2d30e4e2..328ffd96015 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -338,6 +338,9 @@ public:
     return getTypeWidth(IntMaxType);
   }
 
+  // Return the size of unwind_word for this target.
+  unsigned getUnwindWordWidth() const { return getPointerWidth(0); }
+
   /// \brief Return the "preferred" register width on this target.
   uint64_t getRegisterWidth() const {
     // Currently we assume the register width on the target matches the pointer
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index aabf061c321..accea53bb84 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3270,6 +3270,10 @@ static void handleModeAttr(Sema &S, Decl *D, const AttributeList &Attr) {
     if (Str == "pointer")
       DestWidth = S.Context.getTargetInfo().getPointerWidth(0);
     break;
+  case 11:
+    if (Str == "unwind_word")
+      DestWidth = S.Context.Target.getUnwindWordWidth();
+    break;
   }
 
   QualType OldTy;
diff --git a/clang/test/Sema/attr-mode.c b/clang/test/Sema/attr-mode.c
index 0c5336282c4..a89c8397e0a 100644
--- a/clang/test/Sema/attr-mode.c
+++ b/clang/test/Sema/attr-mode.c
@@ -17,6 +17,8 @@ typedef int invalid_3 __attribute((mode(II))); // expected-error{{unknown machin
 typedef struct {int i,j,k;} invalid_4 __attribute((mode(SI))); // expected-error{{mode attribute only supported for integer and floating-point types}}
 typedef float invalid_5 __attribute((mode(SI))); // expected-error{{type of machine mode does not match type of base type}}
 
+typedef unsigned unwind_word __attribute((mode(unwind_word)));
+
 int **__attribute((mode(QI)))* i32;  // expected-error{{mode attribute}}
 
 typedef _Complex double c32 __attribute((mode(SC)));