[XRay] Add -fxray-{always,never}-instrument= flags to clang

Summary:
The -fxray-always-instrument= and -fxray-never-instrument= flags take
filenames that are used to imbue the XRay instrumentation attributes
using a whitelist mechanism (similar to the sanitizer special cases
list). We use the same syntax and semantics as the sanitizer blacklists
files in the implementation.

As implemented, we respect the attributes that are already defined in
the source file (i.e. those that have the
[[clang::xray_{always,never}_instrument]] attributes) before applying
the always/never instrument lists.

Reviewers: rsmith, chandlerc

Subscribers: jfb, mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D30388

llvm-svn: 299041

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index 5c9dd96..ce8c582 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -28,6 +28,7 @@
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/Module.h"
 #include "clang/Basic/SanitizerBlacklist.h"
+#include "clang/Basic/XRayLists.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
@@ -1125,6 +1126,12 @@ public:
                               QualType Ty,
                               StringRef Category = StringRef()) const;
 
+  /// Imbue XRay attributes to a function, applying the always/never attribute
+  /// lists in the process. Returns true if we did imbue attributes this way,
+  /// false otherwise.
+  bool imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
+                      StringRef Category = StringRef()) const;
+
   SanitizerMetadata *getSanitizerMetadata() {
     return SanitizerMD.get();
   }