On Darwin, the linker removes functions in CommentDumper.o (Comment::dump())

despite __attribute__(__used__).  As explained by Argyrios,
> .a archive files do some stripping of their own and they remove .o files that
> contain functions that are not referenced by any other .o file.

The fix is to use these functions from another .o file.

Thanks, Argyrios!

llvm-svn: 160437

1 files changed, 14 insertions, 0 deletions

diff --git a/clang/lib/AST/Comment.cpp b/clang/lib/AST/Comment.cpp
index 1520d134172..e215e63dec9 100644
--- a/clang/lib/AST/Comment.cpp
+++ b/clang/lib/AST/Comment.cpp
@@ -9,6 +9,7 @@
 
 #include "clang/AST/Comment.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
 
 namespace clang {
 namespace comments {
@@ -27,6 +28,19 @@ const char *Comment::getCommentKindName() const {
   llvm_unreachable("Unknown comment kind!");
 }
 
+void Comment::dump() const {
+  // It is important that Comment::dump() is defined in a different TU than
+  // Comment::dump(raw_ostream, SourceManager).  If both functions were defined
+  // in CommentDumper.cpp, that object file would be removed by linker because
+  // none of its functions are referenced by other object files, despite the
+  // LLVM_ATTRIBUTE_USED.
+  dump(llvm::errs(), NULL);
+}
+
+void Comment::dump(SourceManager &SM) const {
+  dump(llvm::errs(), &SM);
+}
+
 namespace {
 struct good {};
 struct bad {};