[ASTMatchers] Matchers for new[] operators

Two new matchers for `CXXNewExpr` are added which may be useful e.g. in
`clang-tidy` checkers. One of them is `isArray` which matches `new[]` but not
plain `new`. The other one, `hasArraySize` matches `new[]` for a given size.

llvm-svn: 318909

clang/docs/LibASTMatchersReference.html

@@ -2276,6 +2276,16 @@ Given
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1CXXNewExpr.html">CXXNewExpr</a>&gt;</td><td class="name" onclick="toggle('isArray0')"><a name="isArray0Anchor">isArray</a></td><td></td></tr>
+<tr><td colspan="4" class="doc" id="isArray0"><pre>Matches array new expressions.
+
+Given:
+  MyClass *p1 = new MyClass[10];
+cxxNewExpr(isArray())
+  matches the expression 'new MyClass[10]'.
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1CXXOperatorCallExpr.html">CXXOperatorCallExpr</a>&gt;</td><td class="name" onclick="toggle('hasOverloadedOperatorName1')"><a name="hasOverloadedOperatorName1Anchor">hasOverloadedOperatorName</a></td><td>StringRef Name</td></tr>
 <tr><td colspan="4" class="doc" id="hasOverloadedOperatorName1"><pre>Matches overloaded operator names.
 
@@ -4476,6 +4486,16 @@ Example matches A() in the last line
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1CXXNewExpr.html">CXXNewExpr</a>&gt;</td><td class="name" onclick="toggle('hasArraySize0')"><a name="hasArraySize0Anchor">hasArraySize</a></td><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1Expr.html">Expr</a>&gt; InnerMatcher</td></tr>
+<tr><td colspan="4" class="doc" id="hasArraySize0"><pre>Matches array new expressions with a given array size.
+
+Given:
+  MyClass *p1 = new MyClass[10];
+cxxNewExpr(hasArraySize(intgerLiteral(equals(10))))
+  matches the expression 'new MyClass[10]'.
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1CXXNewExpr.html">CXXNewExpr</a>&gt;</td><td class="name" onclick="toggle('hasDeclaration12')"><a name="hasDeclaration12Anchor">hasDeclaration</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="hasDeclaration12"><pre>Matches a node if the declaration associated with that node
 matches the given matcher.

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -5828,6 +5828,31 @@ AST_MATCHER(ParmVarDecl, hasDefaultArgument) {
   return Node.hasDefaultArg(); 
 }
 
+/// \brief Matches array new expressions.
+///
+/// Given:
+/// \code
+///   MyClass *p1 = new MyClass[10];
+/// \endcode
+/// cxxNewExpr(isArray())
+///   matches the expression 'new MyClass[10]'.
+AST_MATCHER(CXXNewExpr, isArray) {
+  return Node.isArray();
+}
+
+/// \brief Matches array new expressions with a given array size.
+///
+/// Given:
+/// \code
+///   MyClass *p1 = new MyClass[10];
+/// \endcode
+/// cxxNewExpr(hasArraySize(intgerLiteral(equals(10))))
+///   matches the expression 'new MyClass[10]'.
+AST_MATCHER_P(CXXNewExpr, hasArraySize, internal::Matcher<Expr>, InnerMatcher) {
+  return Node.isArray() &&
+    InnerMatcher.matches(*Node.getArraySize(), Finder, Builder);
+}
+
 } // namespace ast_matchers
 } // namespace clang
 

clang/lib/ASTMatchers/Dynamic/Registry.cpp

@@ -234,6 +234,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(hasAnyUsingShadowDecl);
   REGISTER_MATCHER(hasArgument);
   REGISTER_MATCHER(hasArgumentOfType);
+  REGISTER_MATCHER(hasArraySize);
   REGISTER_MATCHER(hasAttr);
   REGISTER_MATCHER(hasAutomaticStorageDuration);
   REGISTER_MATCHER(hasBase);
@@ -317,6 +318,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(isAnonymous);
   REGISTER_MATCHER(isAnyCharacter);
   REGISTER_MATCHER(isAnyPointer);
+  REGISTER_MATCHER(isArray);
   REGISTER_MATCHER(isArrow);
   REGISTER_MATCHER(isBaseInitializer);
   REGISTER_MATCHER(isBitField);

clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp

@@ -1998,5 +1998,15 @@ TEST(HasDefaultArgument, Basic) {
                       parmVarDecl(hasDefaultArgument())));
 }
 
+TEST(IsArray, Basic) {
+  EXPECT_TRUE(matches("struct MyClass {}; MyClass *p1 = new MyClass[10];",
+                      cxxNewExpr(isArray())));
+}
+
+TEST(HasArraySize, Basic) {
+  EXPECT_TRUE(matches("struct MyClass {}; MyClass *p1 = new MyClass[10];",
+                      cxxNewExpr(hasArraySize(integerLiteral(equals(10))))));
+}
+
 } // namespace ast_matchers
 } // namespace clang