[ASTMatchers] Expand isInline matcher to VarDecl

Add support to the `isInline` matcher for C++17's inline variables.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D118900

clang/docs/LibASTMatchersReference.html

@@ -4322,7 +4322,7 @@ varDecl(isExternC())
 
 
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1FunctionDecl.html">FunctionDecl</a>&gt;</td><td class="name" onclick="toggle('isInline1')"><a name="isInline1Anchor">isInline</a></td><td></td></tr>
-<tr><td colspan="4" class="doc" id="isInline1"><pre>Matches function and namespace declarations that are marked with
+<tr><td colspan="4" class="doc" id="isInline1"><pre>Matches functions, variables and namespace declarations that are marked with
 the inline keyword.
 
 Given
@@ -4331,8 +4331,10 @@ Given
   namespace n {
   inline namespace m {}
   }
+  inline int Foo = 5;
 functionDecl(isInline()) will match ::f().
 namespaceDecl(isInline()) will match n::m.
+varDecl(isInline()) will match Foo;
 </pre></td></tr>
 
 
@@ -4697,7 +4699,7 @@ namespaceDecl(isAnonymous()) will match #1 but not ::n.
 
 
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1NamespaceDecl.html">NamespaceDecl</a>&gt;</td><td class="name" onclick="toggle('isInline0')"><a name="isInline0Anchor">isInline</a></td><td></td></tr>
-<tr><td colspan="4" class="doc" id="isInline0"><pre>Matches function and namespace declarations that are marked with
+<tr><td colspan="4" class="doc" id="isInline0"><pre>Matches functions, variables and namespace declarations that are marked with
 the inline keyword.
 
 Given
@@ -4706,8 +4708,10 @@ Given
   namespace n {
   inline namespace m {}
   }
+  inline int Foo = 5;
 functionDecl(isInline()) will match ::f().
 namespaceDecl(isInline()) will match n::m.
+varDecl(isInline()) will match Foo;
 </pre></td></tr>
 
 
@@ -5728,6 +5732,23 @@ auto f = [x=3]() { return x; };
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1VarDecl.html">VarDecl</a>&gt;</td><td class="name" onclick="toggle('isInline2')"><a name="isInline2Anchor">isInline</a></td><td></td></tr>
+<tr><td colspan="4" class="doc" id="isInline2"><pre>Matches functions, variables and namespace declarations that are marked with
+the inline keyword.
+
+Given
+  inline void f();
+  void g();
+  namespace n {
+  inline namespace m {}
+  }
+  inline int Foo = 5;
+functionDecl(isInline()) will match ::f().
+namespaceDecl(isInline()) will match n::m.
+varDecl(isInline()) will match Foo;
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1VarDecl.html">VarDecl</a>&gt;</td><td class="name" onclick="toggle('isStaticLocal0')"><a name="isStaticLocal0Anchor">isStaticLocal</a></td><td></td></tr>
 <tr><td colspan="4" class="doc" id="isStaticLocal0"><pre>Matches a static variable with local scope.
 

clang/docs/ReleaseNotes.rst

@@ -186,6 +186,8 @@ Build System Changes
 AST Matchers
 ------------
 
+- Expanded ``isInline`` narrowing matcher to support c++17 inline variables.
+
 clang-format
 ------------
 

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -7673,7 +7673,7 @@ AST_MATCHER_P(FunctionDecl, hasExplicitSpecifier, internal::Matcher<Expr>,
   return InnerMatcher.matches(*ES.getExpr(), Finder, Builder);
 }
 
-/// Matches function and namespace declarations that are marked with
+/// Matches functions, variables and namespace declarations that are marked with
 /// the inline keyword.
 ///
 /// Given
@@ -7683,18 +7683,22 @@ AST_MATCHER_P(FunctionDecl, hasExplicitSpecifier, internal::Matcher<Expr>,
 ///   namespace n {
 ///   inline namespace m {}
 ///   }
+///   inline int Foo = 5;
 /// \endcode
 /// functionDecl(isInline()) will match ::f().
 /// namespaceDecl(isInline()) will match n::m.
-AST_POLYMORPHIC_MATCHER(isInline,
-                        AST_POLYMORPHIC_SUPPORTED_TYPES(NamespaceDecl,
-                                                        FunctionDecl)) {
+/// varDecl(isInline()) will match Foo;
+AST_POLYMORPHIC_MATCHER(isInline, AST_POLYMORPHIC_SUPPORTED_TYPES(NamespaceDecl,
+                                                                  FunctionDecl,
+                                                                  VarDecl)) {
   // This is required because the spelling of the function used to determine
   // whether inline is specified or not differs between the polymorphic types.
   if (const auto *FD = dyn_cast<FunctionDecl>(&Node))
     return FD->isInlineSpecified();
-  else if (const auto *NSD = dyn_cast<NamespaceDecl>(&Node))
+  if (const auto *NSD = dyn_cast<NamespaceDecl>(&Node))
     return NSD->isInline();
+  if (const auto *VD = dyn_cast<VarDecl>(&Node))
+    return VD->isInline();
   llvm_unreachable("Not a valid polymorphic type");
 }
 

clang/unittests/ASTMatchers/ASTMatchersInternalTest.cpp

@@ -197,6 +197,8 @@ TEST(IsInlineMatcher, IsInline) {
                       functionDecl(isInline(), hasName("f"))));
   EXPECT_TRUE(matches("namespace n { inline namespace m {} }",
                       namespaceDecl(isInline(), hasName("m"))));
+  EXPECT_TRUE(matches("inline int Foo = 5;",
+                      varDecl(isInline(), hasName("Foo")), {Lang_CXX17}));
 }
 
 // FIXME: Figure out how to specify paths so the following tests pass on