add release note, only define for offloading targets, update test

Signed-off-by: Sarnie, Nick <[email protected]>

Author: sarnex

clang/docs/LanguageExtensions.rst

@@ -69,7 +69,8 @@ It can be used like this:
 
   When using device offloading, a builtin is considered available if it is
   available on either the host or the device targets.
-  Use ``__has_target_builtin`` to consider only the current target.
+  Use ``__has_target_builtin`` to consider only the current target for an
+  offloading target.
 
 ``__has_constexpr_builtin``
 ---------------------------
@@ -129,6 +130,8 @@ It can be used like this:
   ``__has_target_builtin`` should not be used to detect support for a builtin macro;
   use ``#ifdef`` instead.
 
+  ``__has_target_built`` is only defined for offloading targets.
+
 .. _langext-__has_feature-__has_extension:
 
 ``__has_feature`` and ``__has_extension``

clang/docs/ReleaseNotes.rst

@@ -104,6 +104,12 @@ Non-comprehensive list of changes in this release
 New Compiler Flags
 ------------------
 
+New Compiler Builtins
+---------------------
+
+- The new ``__has_target_builtin`` macro can be used to check if a builtin is available
+  on the current offloading target.
+
 Deprecated Compiler Flags
 -------------------------
 

clang/lib/Lex/PPMacroExpansion.cpp

@@ -357,7 +357,12 @@ void Preprocessor::RegisterBuiltinMacros() {
   Ident__has_builtin = RegisterBuiltinMacro("__has_builtin");
   Ident__has_constexpr_builtin =
       RegisterBuiltinMacro("__has_constexpr_builtin");
-  Ident__has_target_builtin = RegisterBuiltinMacro("__has_target_builtin");
+  if (getLangOpts().OpenMPIsTargetDevice || getLangOpts().CUDAIsDevice ||
+      getLangOpts().SYCLIsDevice)
+    Ident__has_target_builtin = RegisterBuiltinMacro("__has_target_builtin");
+  else
+    Ident__has_target_builtin = nullptr;
+
   Ident__has_attribute = RegisterBuiltinMacro("__has_attribute");
   if (!getLangOpts().CPlusPlus)
     Ident__has_c_attribute = RegisterBuiltinMacro("__has_c_attribute");

clang/test/Preprocessor/has_target_builtin.cpp

@@ -1,18 +1,27 @@
 // RUN: %clang_cc1 -fopenmp -triple=spirv64 -fopenmp-is-target-device \
-// RUN: -aux-triple x86_64-linux-unknown -E %s | FileCheck -implicit-check-not=BAD %s
+// RUN: -aux-triple x86_64-linux-unknown -E %s | FileCheck -implicit-check-not="{{BAD|DOESNT}}" %s
 
 // RUN: %clang_cc1 -fopenmp -triple=nvptx64 -fopenmp-is-target-device \
-// RUN: -aux-triple x86_64-linux-unknown -E %s | FileCheck -implicit-check-not=BAD %s
+// RUN: -aux-triple x86_64-linux-unknown -E %s | FileCheck -implicit-check-not="{{BAD|DOESNT}}" %s
 
 // RUN: %clang_cc1 -fopenmp -triple=amdgcn-amd-amdhsa -fopenmp-is-target-device \
-// RUN: -aux-triple x86_64-linux-unknown -E %s | FileCheck -implicit-check-not=BAD %s
+// RUN: -aux-triple x86_64-linux-unknown -E %s | FileCheck -implicit-check-not="{{BAD|DOESNT}}" %s
 
 // RUN: %clang_cc1 -fopenmp -triple=aarch64 -fopenmp-is-target-device \
-// RUN: -aux-triple x86_64-linux-unknown -E %s | FileCheck -implicit-check-not=BAD %s
+// RUN: -aux-triple x86_64-linux-unknown -E %s | FileCheck -implicit-check-not="{{BAD|DOESNT}}" %s
+
+// RUN: %clang_cc1 -triple=aarch64 -E %s | FileCheck -check-prefix=CHECK-NOTOFFLOAD -implicit-check-not="{{GOOD|HAS|BAD}}" %s
 
 // CHECK: GOOD
+
+// CHECK-NOTOFFLOAD: DOESNT
+#ifdef __has_target_builtin
+  HAS
 #if __has_target_builtin(__builtin_ia32_pause)
   BAD
 #else
   GOOD
 #endif
+#else
+  DOESNT
+#endif