From: Aaron Ballman <aaron@aaronballman.com>
Date: Fri, 5 Dec 2014 15:24:55 +0000 (+0000)
Subject: Modify __has_attribute so that it only looks for GNU-style attributes. Removes the... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e3446ce886b20b363e093cbd400b6f4337efb6c4;p=clang

Modify __has_attribute so that it only looks for GNU-style attributes. Removes the ability to look for generic attributes and keywords via this macro, which has the potential to be a breaking change. However, since there is __has_cpp_attribute and __has_declspec_attribute, and given the limited usefulness of querying a generic attribute name regardless of syntax, this seems like the correct path forward.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@223468 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index daab804b53..8c47d693ed 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -47,7 +47,11 @@ sections with improvements to Clang's support for those languages.
 Major New Features
 ------------------
 
-- A big one.
+- The __has_attribute built-in macro no longer queries for attributes across
+  multiple attribute syntaxes (GNU, C++11, __declspec, etc). Instead, it only
+  queries GNU-style attributes. With the addition of __has_cpp_attribute and
+  __has_declspec_attribute, this allows for more precise coverage of attribute
+  syntax querying.
 
 
 Improvements to Clang's diagnostics
diff --git a/include/clang/Basic/Attributes.h b/include/clang/Basic/Attributes.h
index 982e12d9f2..10786006f8 100644
--- a/include/clang/Basic/Attributes.h
+++ b/include/clang/Basic/Attributes.h
@@ -18,8 +18,6 @@ namespace clang {
 class IdentifierInfo;
 
 enum class AttrSyntax {
-  /// Is the attribute identifier generally known for any syntax?
-  Generic,
   /// Is the identifier known as a GNU-style attribute?
   GNU,
   /// Is the identifier known as a __declspec-style attribute?
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index 26cf5439e7..b402a939c5 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -1425,7 +1425,7 @@ void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
       // Check for a builtin is trivial.
       Value = FeatureII->getBuiltinID() != 0;
     } else if (II == Ident__has_attribute)
-      Value = hasAttribute(AttrSyntax::Generic, nullptr, FeatureII,
+      Value = hasAttribute(AttrSyntax::GNU, nullptr, FeatureII,
                            getTargetInfo().getTriple(), getLangOpts());
     else if (II == Ident__has_cpp_attribute)
       Value = hasAttribute(AttrSyntax::CXX, ScopeII, FeatureII,
diff --git a/test/Preprocessor/has_attribute.c b/test/Preprocessor/has_attribute.c
index 5fe060e68d..0ef5b4857a 100644
--- a/test/Preprocessor/has_attribute.c
+++ b/test/Preprocessor/has_attribute.c
@@ -48,3 +48,8 @@ int has_no_volatile_attribute();
 #if !__has_attribute(dllexport)
   int does_not_have_dllexport();
 #endif
+
+// CHECK: does_not_have_uuid
+#if !__has_attribute(uuid)
+  int does_not_have_uuid
+#endif
diff --git a/utils/TableGen/ClangAttrEmitter.cpp b/utils/TableGen/ClangAttrEmitter.cpp
index 7847b4f931..67f9452ba6 100644
--- a/utils/TableGen/ClangAttrEmitter.cpp
+++ b/utils/TableGen/ClangAttrEmitter.cpp
@@ -1920,9 +1920,6 @@ void EmitClangAttrHasAttrImpl(RecordKeeper &Records, raw_ostream &OS) {
   }
 
   OS << "switch (Syntax) {\n";
-  OS << "case AttrSyntax::Generic:\n";
-  OS << "  return llvm::StringSwitch<int>(Name)\n";
-  GenerateHasAttrSpellingStringSwitch(Attrs, OS);
   OS << "case AttrSyntax::GNU:\n";
   OS << "  return llvm::StringSwitch<int>(Name)\n";
   GenerateHasAttrSpellingStringSwitch(GNU, OS, "GNU");