[ASTMatchers] Add matchers canReferToDecl() and hasUnderlyingDecl()

Summary: Required for D22220

Reviewers: sbenza, klimek, aaron.ballman, alexfh

Subscribers: alexfh, klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D23004

llvm-svn: 278123

4 files changed, 106 insertions, 0 deletions

diff --git a/clang/docs/LibASTMatchersReference.html b/clang/docs/LibASTMatchersReference.html
index 02af5d578f6..b87cae230bf 100644
--- a/clang/docs/LibASTMatchersReference.html
+++ b/clang/docs/LibASTMatchersReference.html
@@ -4970,6 +4970,19 @@ Usable as: Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1Block
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1NamedDecl.html">NamedDecl</a>&gt;</td><td class="name" onclick="toggle('hasUnderlyingDecl0')"><a name="hasUnderlyingDecl0Anchor">hasUnderlyingDecl</a></td><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1NamedDecl.html">NamedDecl</a>&gt; InnerMatcher</td></tr>
+<tr><td colspan="4" class="doc" id="hasUnderlyingDecl0"><pre>Matches a NamedDecl whose underlying declaration matches the given
+matcher.
+
+Given
+  namespace N { template&lt;class T&gt; void f(T t); }
+  template &lt;class T&gt; void g() { using N::f; f(T()); }
+unresolvedLookupExpr(hasAnyDeclaration(
+    namedDecl(hasUnderlyingDecl(hasName("::N::f")))))
+  matches the use of f in g() .
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1NestedNameSpecifierLoc.html">NestedNameSpecifierLoc</a>&gt;</td><td class="name" onclick="toggle('hasPrefix1')"><a name="hasPrefix1Anchor">hasPrefix</a></td><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1NestedNameSpecifierLoc.html">NestedNameSpecifierLoc</a>&gt; InnerMatcher</td></tr>
 <tr><td colspan="4" class="doc" id="hasPrefix1"><pre>Matches on the prefix of a NestedNameSpecifierLoc.
 
@@ -5057,6 +5070,23 @@ matches the [webView ...] message invocation.
 <tr><td colspan="4" class="doc" id="hasSourceExpression1"><pre></pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1OverloadExpr.html">OverloadExpr</a>&gt;</td><td class="name" onclick="toggle('hasAnyDeclaration0')"><a name="hasAnyDeclaration0Anchor">hasAnyDeclaration</a></td><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt; InnerMatcher</td></tr>
+<tr><td colspan="4" class="doc" id="hasAnyDeclaration0"><pre>Matches an OverloadExpr if any of the declarations in the set of
+overloads matches the given matcher.
+
+Given
+  template &lt;typename T&gt; void foo(T);
+  template &lt;typename T&gt; void bar(T);
+  template &lt;typename T&gt; void baz(T t) {
+    foo(t);
+    bar(t);
+  }
+unresolvedLookupExpr(hasAnyDeclaration(
+    functionTemplateDecl(hasName("foo"))))
+  matches foo in foo(t); but not bar in bar(t);
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1ParenType.html">ParenType</a>&gt;</td><td class="name" onclick="toggle('innerType0')"><a name="innerType0Anchor">innerType</a></td><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1Type.html">Type</a>&gt;</td></tr>
 <tr><td colspan="4" class="doc" id="innerType0"><pre>Matches ParenType nodes where the inner type is a specific type.
 
diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
index 2a5f0470766..6f194e2a57a 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchers.h
+++ b/clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -2468,6 +2468,25 @@ hasDeclaration(const internal::Matcher<Decl> &InnerMatcher) {
       void(internal::HasDeclarationSupportedTypes)>(InnerMatcher);
 }
 
+/// \brief Matches a \c NamedDecl whose underlying declaration matches the given
+/// matcher.
+///
+/// Given
+/// \code
+///   namespace N { template<class T> void f(T t); }
+///   template <class T> void g() { using N::f; f(T()); }
+/// \endcode
+/// \c unresolvedLookupExpr(hasAnyDeclaration(
+///     namedDecl(hasUnderlyingDecl(hasName("::N::f")))))
+///   matches the use of \c f in \c g() .
+AST_MATCHER_P(NamedDecl, hasUnderlyingDecl, internal::Matcher<NamedDecl>,
+              InnerMatcher) {
+  const NamedDecl *UnderlyingDecl = Node.getUnderlyingDecl();
+
+  return UnderlyingDecl != nullptr &&
+         InnerMatcher.matches(*UnderlyingDecl, Finder, Builder);
+}
+
 /// \brief Matches on the implicit object argument of a member call expression.
 ///
 /// Example matches y.x()
@@ -2823,6 +2842,27 @@ AST_MATCHER_P(DeclRefExpr, throughUsingDecl,
   return false;
 }
 
+/// \brief Matches an \c OverloadExpr if any of the declarations in the set of
+/// overloads matches the given matcher.
+///
+/// Given
+/// \code
+///   template <typename T> void foo(T);
+///   template <typename T> void bar(T);
+///   template <typename T> void baz(T t) {
+///     foo(t);
+///     bar(t);
+///   }
+/// \endcode
+/// unresolvedLookupExpr(hasAnyDeclaration(
+///     functionTemplateDecl(hasName("foo"))))
+///   matches \c foo in \c foo(t); but not \c bar in \c bar(t);
+AST_MATCHER_P(OverloadExpr, hasAnyDeclaration, internal::Matcher<Decl>,
+              InnerMatcher) {
+  return matchesFirstInPointerRange(InnerMatcher, Node.decls_begin(),
+                                    Node.decls_end(), Finder, Builder);
+}
+
 /// \brief Matches the Decl of a DeclStmt which has a single declaration.
 ///
 /// Given
diff --git a/clang/lib/ASTMatchers/Dynamic/Registry.cpp b/clang/lib/ASTMatchers/Dynamic/Registry.cpp
index 24ff30cd7bc..c5be3d530ad 100644
--- a/clang/lib/ASTMatchers/Dynamic/Registry.cpp
+++ b/clang/lib/ASTMatchers/Dynamic/Registry.cpp
@@ -198,6 +198,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(hasAncestor);
   REGISTER_MATCHER(hasAnyArgument);
   REGISTER_MATCHER(hasAnyConstructorInitializer);
+  REGISTER_MATCHER(hasAnyDeclaration);
   REGISTER_MATCHER(hasAnyName);
   REGISTER_MATCHER(hasAnyParameter);
   REGISTER_MATCHER(hasAnySubstatement);
@@ -265,6 +266,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(hasTypeLoc);
   REGISTER_MATCHER(hasUnaryOperand);
   REGISTER_MATCHER(hasUnarySelector);
+  REGISTER_MATCHER(hasUnderlyingDecl);
   REGISTER_MATCHER(hasValueType);
   REGISTER_MATCHER(ifStmt);
   REGISTER_MATCHER(ignoringImplicit);
diff --git a/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
index 41d588f122b..fcd3dcb5af0 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
@@ -241,6 +241,21 @@ TEST(HasDeclaration, HasDeclarationOfTemplateSpecializationType) {
                         hasDeclaration(namedDecl(hasName("A"))))))));
 }
 
+TEST(HasUnderlyingDecl, Matches) {
+  EXPECT_TRUE(matches("namespace N { template <class T> void f(T t); }"
+                      "template <class T> void g() { using N::f; f(T()); }",
+                      unresolvedLookupExpr(hasAnyDeclaration(
+                          namedDecl(hasUnderlyingDecl(hasName("::N::f")))))));
+  EXPECT_TRUE(matches(
+      "namespace N { template <class T> void f(T t); }"
+      "template <class T> void g() { N::f(T()); }",
+      unresolvedLookupExpr(hasAnyDeclaration(namedDecl(hasName("::N::f"))))));
+  EXPECT_TRUE(notMatches(
+      "namespace N { template <class T> void f(T t); }"
+      "template <class T> void g() { using N::f; f(T()); }",
+      unresolvedLookupExpr(hasAnyDeclaration(namedDecl(hasName("::N::f"))))));
+}
+
 TEST(HasType, TakesQualTypeMatcherAndMatchesExpr) {
   TypeMatcher ClassX = hasDeclaration(recordDecl(hasName("X")));
   EXPECT_TRUE(
@@ -2072,5 +2087,24 @@ TEST(Matcher, ForEachOverriden) {
   EXPECT_TRUE(notMatches(Code2, ForEachOverriddenInClass("A1")));
 }
 
+TEST(Matcher, HasAnyDeclaration) {
+  std::string Fragment = "void foo(int p1);"
+                         "void foo(int *p2);"
+                         "void bar(int p3);"
+                         "template <typename T> void baz(T t) { foo(t); }";
+
+  EXPECT_TRUE(
+      matches(Fragment, unresolvedLookupExpr(hasAnyDeclaration(functionDecl(
+                            hasParameter(0, parmVarDecl(hasName("p1"))))))));
+  EXPECT_TRUE(
+      matches(Fragment, unresolvedLookupExpr(hasAnyDeclaration(functionDecl(
+                            hasParameter(0, parmVarDecl(hasName("p2"))))))));
+  EXPECT_TRUE(
+      notMatches(Fragment, unresolvedLookupExpr(hasAnyDeclaration(functionDecl(
+                               hasParameter(0, parmVarDecl(hasName("p3"))))))));
+  EXPECT_TRUE(notMatches(Fragment, unresolvedLookupExpr(hasAnyDeclaration(
+                                       functionDecl(hasName("bar"))))));
+}
+
 } // namespace ast_matchers
 } // namespace clang