Index: clang/docs/LibASTMatchersReference.html
===================================================================
--- clang/docs/LibASTMatchersReference.html
+++ clang/docs/LibASTMatchersReference.html
@@ -573,6 +573,15 @@
 <tr style="text-align:left"><th>Return type</th><th>Name</th><th>Parameters</th></tr>
 <!-- START_DECL_MATCHERS -->
 
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXBaseSpecifier.html">CXXBaseSpecifier</a>&gt;</td><td class="name" onclick="toggle('cxxBaseSpecifier0')"><a name="cxxBaseSpecifier0Anchor">cxxBaseSpecifier</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXBaseSpecifier.html">CXXBaseSpecifier</a>&gt;...</td></tr>
+<tr><td colspan="4" class="doc" id="cxxBaseSpecifier0"><pre>Matches class bases.
+
+Examples matches public virtual B.
+  class B {};
+  class C : public virtual B {};
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXCtorInitializer.html">CXXCtorInitializer</a>&gt;</td><td class="name" onclick="toggle('cxxCtorInitializer0')"><a name="cxxCtorInitializer0Anchor">cxxCtorInitializer</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXCtorInitializer.html">CXXCtorInitializer</a>&gt;...</td></tr>
 <tr><td colspan="4" class="doc" id="cxxCtorInitializer0"><pre>Matches constructor initializers.
 
@@ -6109,8 +6118,8 @@
 </pre></td></tr>
 
 
-<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXBaseSpecifier.html">CXXBaseSpecifier</a>&gt;</td><td class="name" onclick="toggle('hasType7')"><a name="hasType7Anchor">hasType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt; InnerMatcher</td></tr>
-<tr><td colspan="4" class="doc" id="hasType7"><pre>Overloaded to match the declaration of the expression's or value
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXBaseSpecifier.html">CXXBaseSpecifier</a>&gt;</td><td class="name" onclick="toggle('hasType8')"><a name="hasType8Anchor">hasType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt; InnerMatcher</td></tr>
+<tr><td colspan="4" class="doc" id="hasType8"><pre>Overloaded to match the declaration of the expression's or value
 declaration's type.
 
 In case of a value declaration (for example a variable declaration),
@@ -6122,9 +6131,12 @@
 Example matches x (matcher = expr(hasType(cxxRecordDecl(hasName("X")))))
             and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
             and friend class X (matcher = friendDecl(hasType("X"))
+            and public virtual X (matcher = cxxBaseSpecifier(hasType(
+                                              cxxRecordDecl(hasName("X"))))
  class X {};
  void y(X &amp;x) { x; X z; }
  class Y { friend class X; };
+ class Z : public virtual X {};
 
 Example matches class Derived
 (matcher = cxxRecordDecl(hasAnyBase(hasType(cxxRecordDecl(hasName("Base"))))))
@@ -6136,6 +6148,24 @@
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXBaseSpecifier.html">CXXBaseSpecifier</a>&gt;</td><td class="name" onclick="toggle('hasType4')"><a name="hasType4Anchor">hasType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1QualType.html">QualType</a>&gt; InnerMatcher</td></tr>
+<tr><td colspan="4" class="doc" id="hasType4"><pre>Matches if the expression's or declaration's type matches a type
+matcher.
+
+Example matches x (matcher = expr(hasType(cxxRecordDecl(hasName("X")))))
+            and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
+            and U (matcher = typedefDecl(hasType(asString("int")))
+            and friend class X (matcher = friendDecl(hasType("X"))
+            and public virtual X (matcher = cxxBaseSpecifier(hasType(
+                                              asString("class X")))
+ class X {};
+ void y(X &amp;x) { x; X z; }
+ typedef int U;
+ class Y { friend class X; };
+ class Z : public virtual X {};
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXConstructExpr.html">CXXConstructExpr</a>&gt;</td><td class="name" onclick="toggle('forEachArgumentWithParam1')"><a name="forEachArgumentWithParam1Anchor">forEachArgumentWithParam</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Expr.html">Expr</a>&gt; ArgMatcher, Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ParmVarDecl.html">ParmVarDecl</a>&gt; ParamMatcher</td></tr>
 <tr><td colspan="4" class="doc" id="forEachArgumentWithParam1"><pre>Matches all arguments and their respective ParmVarDecl.
 
@@ -7247,8 +7277,8 @@
 </pre></td></tr>
 
 
-<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Expr.html">Expr</a>&gt;</td><td class="name" onclick="toggle('hasType4')"><a name="hasType4Anchor">hasType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt; InnerMatcher</td></tr>
-<tr><td colspan="4" class="doc" id="hasType4"><pre>Overloaded to match the declaration of the expression's or value
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Expr.html">Expr</a>&gt;</td><td class="name" onclick="toggle('hasType5')"><a name="hasType5Anchor">hasType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt; InnerMatcher</td></tr>
+<tr><td colspan="4" class="doc" id="hasType5"><pre>Overloaded to match the declaration of the expression's or value
 declaration's type.
 
 In case of a value declaration (for example a variable declaration),
@@ -7260,9 +7290,12 @@
 Example matches x (matcher = expr(hasType(cxxRecordDecl(hasName("X")))))
             and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
             and friend class X (matcher = friendDecl(hasType("X"))
+            and public virtual X (matcher = cxxBaseSpecifier(hasType(
+                                              cxxRecordDecl(hasName("X"))))
  class X {};
  void y(X &amp;x) { x; X z; }
  class Y { friend class X; };
+ class Z : public virtual X {};
 
 Example matches class Derived
 (matcher = cxxRecordDecl(hasAnyBase(hasType(cxxRecordDecl(hasName("Base"))))))
@@ -7282,10 +7315,13 @@
             and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
             and U (matcher = typedefDecl(hasType(asString("int")))
             and friend class X (matcher = friendDecl(hasType("X"))
+            and public virtual X (matcher = cxxBaseSpecifier(hasType(
+                                              asString("class X")))
  class X {};
  void y(X &amp;x) { x; X z; }
  typedef int U;
  class Y { friend class X; };
+ class Z : public virtual X {};
 </pre></td></tr>
 
 
@@ -7458,8 +7494,8 @@
 </pre></td></tr>
 
 
-<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1FriendDecl.html">FriendDecl</a>&gt;</td><td class="name" onclick="toggle('hasType5')"><a name="hasType5Anchor">hasType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt; InnerMatcher</td></tr>
-<tr><td colspan="4" class="doc" id="hasType5"><pre>Overloaded to match the declaration of the expression's or value
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1FriendDecl.html">FriendDecl</a>&gt;</td><td class="name" onclick="toggle('hasType6')"><a name="hasType6Anchor">hasType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt; InnerMatcher</td></tr>
+<tr><td colspan="4" class="doc" id="hasType6"><pre>Overloaded to match the declaration of the expression's or value
 declaration's type.
 
 In case of a value declaration (for example a variable declaration),
@@ -7471,9 +7507,12 @@
 Example matches x (matcher = expr(hasType(cxxRecordDecl(hasName("X")))))
             and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
             and friend class X (matcher = friendDecl(hasType("X"))
+            and public virtual X (matcher = cxxBaseSpecifier(hasType(
+                                              cxxRecordDecl(hasName("X"))))
  class X {};
  void y(X &amp;x) { x; X z; }
  class Y { friend class X; };
+ class Z : public virtual X {};
 
 Example matches class Derived
 (matcher = cxxRecordDecl(hasAnyBase(hasType(cxxRecordDecl(hasName("Base"))))))
@@ -7493,10 +7532,13 @@
             and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
             and U (matcher = typedefDecl(hasType(asString("int")))
             and friend class X (matcher = friendDecl(hasType("X"))
+            and public virtual X (matcher = cxxBaseSpecifier(hasType(
+                                              asString("class X")))
  class X {};
  void y(X &amp;x) { x; X z; }
  typedef int U;
  class Y { friend class X; };
+ class Z : public virtual X {};
 </pre></td></tr>
 
 
@@ -8715,10 +8757,13 @@
             and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
             and U (matcher = typedefDecl(hasType(asString("int")))
             and friend class X (matcher = friendDecl(hasType("X"))
+            and public virtual X (matcher = cxxBaseSpecifier(hasType(
+                                              asString("class X")))
  class X {};
  void y(X &amp;x) { x; X z; }
  typedef int U;
  class Y { friend class X; };
+ class Z : public virtual X {};
 </pre></td></tr>
 
 
@@ -8861,8 +8906,8 @@
   matches using X::b but not using X::a </pre></td></tr>
 
 
-<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ValueDecl.html">ValueDecl</a>&gt;</td><td class="name" onclick="toggle('hasType6')"><a name="hasType6Anchor">hasType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt; InnerMatcher</td></tr>
-<tr><td colspan="4" class="doc" id="hasType6"><pre>Overloaded to match the declaration of the expression's or value
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1ValueDecl.html">ValueDecl</a>&gt;</td><td class="name" onclick="toggle('hasType7')"><a name="hasType7Anchor">hasType</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt; InnerMatcher</td></tr>
+<tr><td colspan="4" class="doc" id="hasType7"><pre>Overloaded to match the declaration of the expression's or value
 declaration's type.
 
 In case of a value declaration (for example a variable declaration),
@@ -8874,9 +8919,12 @@
 Example matches x (matcher = expr(hasType(cxxRecordDecl(hasName("X")))))
             and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
             and friend class X (matcher = friendDecl(hasType("X"))
+            and public virtual X (matcher = cxxBaseSpecifier(hasType(
+                                              cxxRecordDecl(hasName("X"))))
  class X {};
  void y(X &amp;x) { x; X z; }
  class Y { friend class X; };
+ class Z : public virtual X {};
 
 Example matches class Derived
 (matcher = cxxRecordDecl(hasAnyBase(hasType(cxxRecordDecl(hasName("Base"))))))
@@ -8896,10 +8944,13 @@
             and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
             and U (matcher = typedefDecl(hasType(asString("int")))
             and friend class X (matcher = friendDecl(hasType("X"))
+            and public virtual X (matcher = cxxBaseSpecifier(hasType(
+                                              asString("class X")))
  class X {};
  void y(X &amp;x) { x; X z; }
  typedef int U;
  class Y { friend class X; };
+ class Z : public virtual X {};
 </pre></td></tr>
 
 
Index: clang/include/clang/ASTMatchers/ASTMatchers.h
===================================================================
--- clang/include/clang/ASTMatchers/ASTMatchers.h
+++ clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -144,6 +144,7 @@
 using TypeLocMatcher = internal::Matcher<TypeLoc>;
 using NestedNameSpecifierMatcher = internal::Matcher<NestedNameSpecifier>;
 using NestedNameSpecifierLocMatcher = internal::Matcher<NestedNameSpecifierLoc>;
+using CXXBaseSpecifierMatcher = internal::Matcher<CXXBaseSpecifier>;
 using CXXCtorInitializerMatcher = internal::Matcher<CXXCtorInitializer>;
 using TemplateArgumentMatcher = internal::Matcher<TemplateArgument>;
 using TemplateArgumentLocMatcher = internal::Matcher<TemplateArgumentLoc>;
@@ -516,6 +517,15 @@
 extern const internal::VariadicDynCastAllOfMatcher<Decl, AccessSpecDecl>
     accessSpecDecl;
 
+/// Matches class bases.
+///
+/// Examples matches \c public virtual B.
+/// \code
+///   class B {};
+///   class C : public virtual B {};
+/// \endcode
+extern const internal::VariadicAllOfMatcher<CXXBaseSpecifier> cxxBaseSpecifier;
+
 /// Matches constructor initializers.
 ///
 /// Examples matches \c i(42).
@@ -3790,16 +3800,19 @@
 ///             and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
 ///             and U (matcher = typedefDecl(hasType(asString("int")))
 ///             and friend class X (matcher = friendDecl(hasType("X"))
+///             and public virtual X (matcher = cxxBaseSpecifier(hasType(
+///                                               asString("class X")))
 /// \code
 ///  class X {};
 ///  void y(X &x) { x; X z; }
 ///  typedef int U;
 ///  class Y { friend class X; };
+///  class Z : public virtual X {};
 /// \endcode
 AST_POLYMORPHIC_MATCHER_P_OVERLOAD(
     hasType,
     AST_POLYMORPHIC_SUPPORTED_TYPES(Expr, FriendDecl, TypedefNameDecl,
-                                    ValueDecl),
+                                    ValueDecl, CXXBaseSpecifier),
     internal::Matcher<QualType>, InnerMatcher, 0) {
   QualType QT = internal::getUnderlyingType(Node);
   if (!QT.isNull())
@@ -3819,10 +3832,13 @@
 /// Example matches x (matcher = expr(hasType(cxxRecordDecl(hasName("X")))))
 ///             and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
 ///             and friend class X (matcher = friendDecl(hasType("X"))
+///             and public virtual X (matcher = cxxBaseSpecifier(hasType(
+///                                               cxxRecordDecl(hasName("X"))))
 /// \code
 ///  class X {};
 ///  void y(X &x) { x; X z; }
 ///  class Y { friend class X; };
+///  class Z : public virtual X {};
 /// \endcode
 ///
 /// Example matches class Derived
Index: clang/lib/ASTMatchers/ASTMatchersInternal.cpp
===================================================================
--- clang/lib/ASTMatchers/ASTMatchersInternal.cpp
+++ clang/lib/ASTMatchers/ASTMatchersInternal.cpp
@@ -756,6 +756,7 @@
 const internal::VariadicDynCastAllOfMatcher<Decl, ParmVarDecl> parmVarDecl;
 const internal::VariadicDynCastAllOfMatcher<Decl, AccessSpecDecl>
     accessSpecDecl;
+const internal::VariadicAllOfMatcher<CXXBaseSpecifier> cxxBaseSpecifier;
 const internal::VariadicAllOfMatcher<CXXCtorInitializer> cxxCtorInitializer;
 const internal::VariadicAllOfMatcher<TemplateArgument> templateArgument;
 const internal::VariadicAllOfMatcher<TemplateArgumentLoc> templateArgumentLoc;
Index: clang/lib/ASTMatchers/Dynamic/Registry.cpp
===================================================================
--- clang/lib/ASTMatchers/Dynamic/Registry.cpp
+++ clang/lib/ASTMatchers/Dynamic/Registry.cpp
@@ -172,6 +172,7 @@
   REGISTER_MATCHER(containsDeclaration);
   REGISTER_MATCHER(continueStmt);
   REGISTER_MATCHER(cudaKernelCallExpr);
+  REGISTER_MATCHER(cxxBaseSpecifier);
   REGISTER_MATCHER(cxxBindTemporaryExpr);
   REGISTER_MATCHER(cxxBoolLiteral);
   REGISTER_MATCHER(cxxCatchStmt);
Index: clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
===================================================================
--- clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
+++ clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
@@ -4400,6 +4400,13 @@
     return;
   }
 
+  DeclarationMatcher ClassHasAnyDirectBase =
+      cxxRecordDecl(hasDirectBase(cxxBaseSpecifier()));
+  EXPECT_TRUE(notMatches("class X {};", ClassHasAnyDirectBase));
+  EXPECT_TRUE(matches("class X {}; class Y : X {};", ClassHasAnyDirectBase));
+  EXPECT_TRUE(matches("class X {}; class Y : public virtual X {};",
+                      ClassHasAnyDirectBase));
+
   EXPECT_TRUE(matches(
       R"cc(
     class Base {};
Index: clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
===================================================================
--- clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
+++ clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
@@ -320,6 +320,15 @@
             varDecl(hasType(pointsTo(ClassX)))));
 }
 
+TEST(HasType, TakesQualTypeMatcherAndMatchesCXXBaseSpecifier) {
+  TypeMatcher ClassX = hasDeclaration(recordDecl(hasName("X")));
+  CXXBaseSpecifierMatcher BaseClassX = cxxBaseSpecifier(hasType(ClassX));
+  DeclarationMatcher ClassHasBaseClassX =
+      cxxRecordDecl(hasDirectBase(BaseClassX));
+  EXPECT_TRUE(matches("class X {}; class Y : X {};", ClassHasBaseClassX));
+  EXPECT_TRUE(notMatches("class Z {}; class Y : Z {};", ClassHasBaseClassX));
+}
+
 TEST(HasType, TakesDeclMatcherAndMatchesExpr) {
   DeclarationMatcher ClassX = recordDecl(hasName("X"));
   EXPECT_TRUE(
@@ -337,6 +346,15 @@
     notMatches("class X {}; void y() { X *x; }", varDecl(hasType(ClassX))));
 }
 
+TEST(HasType, TakesDeclMatcherAndMatchesCXXBaseSpecifier) {
+  DeclarationMatcher ClassX = recordDecl(hasName("X"));
+  CXXBaseSpecifierMatcher BaseClassX = cxxBaseSpecifier(hasType(ClassX));
+  DeclarationMatcher ClassHasBaseClassX =
+      cxxRecordDecl(hasDirectBase(BaseClassX));
+  EXPECT_TRUE(matches("class X {}; class Y : X {};", ClassHasBaseClassX));
+  EXPECT_TRUE(notMatches("class Z {}; class Y : Z {};", ClassHasBaseClassX));
+}
+
 TEST(HasType, MatchesTypedefDecl) {
   EXPECT_TRUE(matches("typedef int X;", typedefDecl(hasType(asString("int")))));
   EXPECT_TRUE(matches("typedef const int T;",
Index: clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
===================================================================
--- clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
+++ clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
@@ -297,6 +297,17 @@
   EXPECT_TRUE(matches("int b[7];", M));
 }
 
+TEST_F(RegistryTest, CXXBaseSpecifier) {
+  // TODO: rewrite with top-level cxxBaseSpecifier matcher when available
+  DeclarationMatcher ClassHasAnyDirectBase =
+      constructMatcher("cxxRecordDecl",
+                       constructMatcher("hasDirectBase",
+                                        constructMatcher("cxxBaseSpecifier")))
+          .getTypedMatcher<Decl>();
+  EXPECT_TRUE(matches("class X {}; class Y : X {};", ClassHasAnyDirectBase));
+  EXPECT_TRUE(notMatches("class X {};", ClassHasAnyDirectBase));
+}
+
 TEST_F(RegistryTest, CXXCtorInitializer) {
   Matcher<Decl> CtorDecl = constructMatcher(
       "cxxConstructorDecl",