ASTMatcher for Attr

[jpienaar]

Summary

Add a matcher for decls that has a specific attribute.

[klimek]

include/clang/ASTMatchers/ASTMatchers.h

3669–3672

If we have this matcher, do the specialized ones still provide enough value? I was expecting us to either go for the specialized ones, or provide a generic one. Having both in the interface seems odd...

[jpienaar]

Removed specialized attribute matchers in favor of retaining generic one.

include/clang/ASTMatchers/ASTMatchers.h

3669–3672

Agreed. I'll remove the specialized ones.

[klimek]

lib/ASTMatchers/Dynamic/Registry.cpp

185–187

And now that I see how this affects the dynamic matchers, I wonder how we're going to fix that up - that is, we'll need to teach the dynamic matchers to understand the possible clang attributes somehow.

[jpienaar]

Re-implemented by having hasAttr take a parameter of type attr::Kind instead to avoid using templates and ease register dynamic matcher.

[klimek]

lib/ASTMatchers/Dynamic/Marshallers.h

79–88

And that's enough to make the dynamic matchers work? Can you add an example to the dynamic matchers test? Thx!

[jpienaar]

Interface to dynamic matcher using hasAttr now uses a string specification of the attribute instead of requiring the numerical enum value.

[jpienaar]

Small cleanup.

[klimek]

+richard, since this is now touching lib/Basic...

Looks good to me, but I want Richard to take a look whether this makes sense or should be solved differently.

[jpienaar]

Moved getAttrKind to a private method of ArgTypeTraints<attr::Kind>.

[jpienaar]

Changed iterator type to const.

[klimek]

Nice, LG. Let me know if you need me to submit.

[jpienaar]

Thanks, I would need you to submit.

[klimek]

Thx! Committed as r216379.

docs/LibASTMatchersReference.html

 </pre></td></tr>
 
 
-<tr><td>Matcher&lt<a href="http://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt;</td><td class="name" onclick="toggle('hasCudaDeviceAttr0')"><a name="hasCudaDeviceAttr0Anchor">hasCudaDeviceAttr</a></td><td></td></tr>
-<tr><td colspan="4" class="doc" id="hasCudaDeviceAttr0"><pre>Matches declaration that has CUDA device attribute.
+<tr><td>Matcher&lt<a href="http://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt;</td><td class="name" onclick="toggle('hasAttr0')"><a name="hasAttr0Anchor">hasAttr</a></td><td>attr::Kind AttrKind</td></tr>
+<tr><td colspan="4" class="doc" id="hasAttr0"><pre>Matches declaration that has a given attribute.
 
 Given
   __attribute__((device)) void f() { ... }
-matches the function declaration of f.
+decl(hasAttr(clang::attr::CUDADevice)) matches the function declaration of
+f.
 </pre></td></tr>
 
 
-<tr><td>Matcher&lt<a href="http://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt;</td><td class="name" onclick="toggle('hasCudaGlobalAttr0')"><a name="hasCudaGlobalAttr0Anchor">hasCudaGlobalAttr</a></td><td></td></tr>
-<tr><td colspan="4" class="doc" id="hasCudaGlobalAttr0"><pre>Matches declaration that has CUDA global attribute.
-
-Given
-  __attribute__((global)) void f() { ... }
-matches the function declaration of f.
-</pre></td></tr>
-
-
-<tr><td>Matcher&lt<a href="http://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt;</td><td class="name" onclick="toggle('hasCudaHostAttr0')"><a name="hasCudaHostAttr0Anchor">hasCudaHostAttr</a></td><td></td></tr>
-<tr><td colspan="4" class="doc" id="hasCudaHostAttr0"><pre>Matches declaration that has CUDA host attribute.
-
-Given
-  __attribute__((host)) void f() { ... }
-matches the function declaration of f.
-</pre></td></tr>
-
-
 <tr><td>Matcher&lt<a href="http://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt;</td><td class="name" onclick="toggle('isImplicit0')"><a name="isImplicit0Anchor">isImplicit</a></td><td></td></tr>
 <tr><td colspan="4" class="doc" id="isImplicit0"><pre>Matches a declaration that has been implicitly added
 by the compiler (eg. implicit defaultcopy constructors).

include/clang/ASTMatchers/ASTMatchers.h

   return InnerMatcher.matches(*Node.getLHS(), Finder, Builder);
 }
 
-/// \brief Matches CUDA kernel call expression.
+/// \brief Matches declaration that has a given attribute.
 ///
-/// Example matches,
-/// \code
-///   kernel<<<i,j>>>();
-/// \endcode
-const internal::VariadicDynCastAllOfMatcher<Stmt, CUDAKernelCallExpr>
-    CUDAKernelCallExpr;
-
-/// \brief Matches declaration that has CUDA device attribute.
-///
 /// Given
 /// \code
 ///   __attribute__((device)) void f() { ... }
 /// \endcode
-/// matches the function declaration of f.
-AST_MATCHER(Decl, hasCudaDeviceAttr) {
-  return Node.hasAttr<clang::CUDADeviceAttr>();
+/// decl(hasAttr(clang::attr::CUDADevice)) matches the function declaration of
+/// f.
+AST_MATCHER_P(Decl, hasAttr, attr::Kind, AttrKind) {
+  for (const auto *Attr : Node.attrs()) {
+    if (Attr->getKind() == AttrKind)
+      return true;
+  }
+  return false;
 }
 
-/// \brief Matches declaration that has CUDA host attribute.
+/// \brief Matches CUDA kernel call expression.
 ///
-/// Given
+/// Example matches,
 /// \code
-///   __attribute__((host)) void f() { ... }
+///   kernel<<<i,j>>>();
 /// \endcode
-/// matches the function declaration of f.
-AST_MATCHER(Decl, hasCudaHostAttr) {
-  return Node.hasAttr<clang::CUDAHostAttr>();
-}
+const internal::VariadicDynCastAllOfMatcher<Stmt, CUDAKernelCallExpr>
+    CUDAKernelCallExpr;
 
-/// \brief  Matches declaration that has CUDA global attribute.
-///
-/// Given
-/// \code
-///   __attribute__((global)) void f() { ... }
-/// \endcode
-/// matches the function declaration of f.
-AST_MATCHER(Decl, hasCudaGlobalAttr) {
-  return Node.hasAttr<clang::CUDAGlobalAttr>();
-}
-
 } // end namespace ast_matchers
 } // end namespace clang
 

lib/ASTMatchers/Dynamic/Marshallers.h

   }
 };
 
+template <> struct ArgTypeTraits<attr::Kind> {
+private:
+  static attr::Kind getAttrKind(llvm::StringRef AttrKind) {
+    return llvm::StringSwitch<attr::Kind>(AttrKind)
+#define ATTR(X) .Case("attr::" #X, attr:: X)
+#include "clang/Basic/AttrList.inc"
+        .Default(attr::Kind(-1));
+  }
+public:
+  static bool is(const VariantValue &Value) {
+    return Value.isString() &&
+        getAttrKind(Value.getString()) != attr::Kind(-1);
+  }
+  static attr::Kind get(const VariantValue &Value) {
+    return getAttrKind(Value.getString());
+  }
+  static ArgKind getKind() {
+    return ArgKind(ArgKind::AK_String);
+  }
+};
+
 /// \brief Matcher descriptor interface.
 ///
 /// Provides a \c create() method that constructs the matcher from the provided

lib/ASTMatchers/Dynamic/Registry.cpp

   REGISTER_MATCHER(hasAnyUsingShadowDecl);
   REGISTER_MATCHER(hasArgument);
   REGISTER_MATCHER(hasArgumentOfType);
+  REGISTER_MATCHER(hasAttr);
   REGISTER_MATCHER(hasBase);
   REGISTER_MATCHER(hasBody);
   REGISTER_MATCHER(hasCanonicalType);

   REGISTER_MATCHER(hasCaseConstant);
   REGISTER_MATCHER(hasCondition);
   REGISTER_MATCHER(hasConditionVariableStatement);
-  REGISTER_MATCHER(hasCudaDeviceAttr);
-  REGISTER_MATCHER(hasCudaGlobalAttr);
-  REGISTER_MATCHER(hasCudaHostAttr);
   REGISTER_MATCHER(hasDeclContext);
   REGISTER_MATCHER(hasDeclaration);
   REGISTER_MATCHER(hasDeducedType);

unittests/ASTMatchers/ASTMatchersTest.cpp

   EXPECT_TRUE(matches("void f() { int i; }", CannotMemoize));
 }
 
+TEST(DeclarationMatcher, HasAttr) {
+  EXPECT_TRUE(matches("struct __attribute__((warn_unused)) X {};",
+                      decl(hasAttr(clang::attr::WarnUnused))));
+  EXPECT_FALSE(matches("struct X {};",
+                       decl(hasAttr(clang::attr::WarnUnused))));
+}
+
 TEST(DeclarationMatcher, MatchCudaDecl) {
   EXPECT_TRUE(matchesWithCuda("__global__ void f() { }"
                               "void g() { f<<<1, 2>>>(); }",
                               CUDAKernelCallExpr()));
   EXPECT_TRUE(matchesWithCuda("__attribute__((device)) void f() {}",
-                              hasCudaDeviceAttr()));
-  EXPECT_TRUE(matchesWithCuda("__attribute__((host)) void f() {}",
-                              hasCudaHostAttr()));
-  EXPECT_TRUE(matchesWithCuda("__attribute__((global)) void f() {}",
-                              hasCudaGlobalAttr()));
-  EXPECT_FALSE(matchesWithCuda("void f() {}",
-                               hasCudaGlobalAttr()));
+                              hasAttr(clang::attr::CUDADevice)));
   EXPECT_TRUE(notMatchesWithCuda("void f() {}",
-                                 hasCudaGlobalAttr()));
+                                 CUDAKernelCallExpr()));
   EXPECT_FALSE(notMatchesWithCuda("__attribute__((global)) void f() {}",
-                                  hasCudaGlobalAttr()));
+                                  hasAttr(clang::attr::CUDAGlobal)));
 }
 
 // Implements a run method that returns whether BoundNodes contains a

unittests/ASTMatchers/Dynamic/RegistryTest.cpp

                             "Matcher<NamedDecl> hasName(string)"));
 }
 
+TEST_F(RegistryTest, HasArgs) {
+  Matcher<Decl> Value = constructMatcher(
+      "decl", constructMatcher("hasAttr", std::string("attr::WarnUnused")))
+      .getTypedMatcher<Decl>();
+  EXPECT_TRUE(matches("struct __attribute__((warn_unused)) X {};", Value));
+  EXPECT_FALSE(matches("struct X {};", Value));
+}
+
 } // end anonymous namespace
 } // end namespace dynamic
 } // end namespace ast_matchers