[ASTMatchers] Add hasInClassInitializer traversal matcher for FieldDecl.

[malcolm.parsons]

Summary

I needed to know whether a FieldDecl had an in-class
initializer for D26453. I used a narrowing matcher there, but a
traversal matcher might be generally useful.

VarDecl has a hasInitializer traversal matcher.
ForStmt has a withLoopInit traversal matcher.
CXXCtorInitializer has a withInitializer traversal matcher.
EnumConstantDecl doesn't have a traversal matcher for its initializer.
IfStmt doesn't have a traversal matcher for its initializer.

[Prazek]

docs/LibASTMatchersReference.html

2442 ↗

(On Diff #82278)

Fix not connected to patch?

4763 ↗

(On Diff #82278)

It would be good to add int c; without initializer and show that fieldDecl(hasInClassInitializer(anything())) will match to a and b

include/clang/ASTMatchers/ASTMatchers.h

547 ↗

(On Diff #82278)

Samw

[malcolm.parsons]

docs/LibASTMatchersReference.html

2442 ↗

(On Diff #82278)

Yes. The documentation is generated from the comments.

include/clang/ASTMatchers/ASTMatchers.h

547 ↗

(On Diff #82278)

Yes.

[aaron.ballman]

LGTM, modulo the unrelated documentation changes.

[malcolm.parsons]

Improve doc.

cfe/trunk/docs/LibASTMatchersReference.html

 would match the declarations for a, b, c, and d, but not e.
 while
    varDecl(hasInitializer(integerLiteral()))
    varDecl(hasInitializer(declRefExpr()))
 would only match the declaration for a.
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1FieldDecl.html">FieldDecl</a>&gt;</td><td class="name" onclick="toggle('hasInClassInitializer0')"><a name="hasInClassInitializer0Anchor">hasInClassInitializer</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="hasInClassInitializer0"><pre>Matches non-static data members that have an in-class initializer.
+
+Given
+  class C {
+    int a = 2;
+    int b = 3;
+    int c;
+  };
+fieldDecl(hasInClassInitializer(integerLiteral(equals(2))))
+  matches 'int a;' but not 'int b;'.
+fieldDecl(hasInClassInitializer(anything()))
+  matches 'int a;' and 'int b;' but not 'int c;'.
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1ForStmt.html">ForStmt</a>&gt;</td><td class="name" onclick="toggle('hasBody1')"><a name="hasBody1Anchor">hasBody</a></td><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>&gt; InnerMatcher</td></tr>
 <tr><td colspan="4" class="doc" id="hasBody1"><pre>Matches a 'for', 'while', 'do while' statement or a function
 definition that has a given body.
 
 Given
   for (;;) {}
 hasBody(compoundStmt())
   matches 'for (;;) {}'

cfe/trunk/include/clang/ASTMatchers/ASTMatchers.h

 /// \endcode
 /// fieldDecl(hasBitWidth(2))
 ///   matches 'int a;' and 'int c;' but not 'int b;'.
 AST_MATCHER_P(FieldDecl, hasBitWidth, unsigned, Width) {
   return Node.isBitField() &&
          Node.getBitWidthValue(Finder->getASTContext()) == Width;
 }
 
+/// \brief Matches non-static data members that have an in-class initializer.
+///
+/// Given
+/// \code
+///   class C {
+///     int a = 2;
+///     int b = 3;
+///     int c;
+///   };
+/// \endcode
+/// fieldDecl(hasInClassInitializer(integerLiteral(equals(2))))
+///   matches 'int a;' but not 'int b;'.
+/// fieldDecl(hasInClassInitializer(anything()))
+///   matches 'int a;' and 'int b;' but not 'int c;'.
+AST_MATCHER_P(FieldDecl, hasInClassInitializer, internal::Matcher<Expr>,
+              InnerMatcher) {
+  const Expr *Initializer = Node.getInClassInitializer();
+  return (Initializer != nullptr &&
+          InnerMatcher.matches(*Initializer, Finder, Builder));
+}
+
 /// \brief Matches a declaration that has been implicitly added
 /// by the compiler (eg. implicit default/copy constructors).
 AST_MATCHER(Decl, isImplicit) {
   return Node.isImplicit();
 }
 
 /// \brief Matches classTemplateSpecializations, templateSpecializationType and
 /// functionDecl that have at least one TemplateArgument matching the given

cfe/trunk/lib/ASTMatchers/Dynamic/Registry.cpp

RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(hasDynamicExceptionSpec);
   REGISTER_MATCHER(hasEitherOperand);
   REGISTER_MATCHER(hasElementType);
   REGISTER_MATCHER(hasElse);
   REGISTER_MATCHER(hasExternalFormalLinkage);
   REGISTER_MATCHER(hasFalseExpression);
   REGISTER_MATCHER(hasGlobalStorage);
   REGISTER_MATCHER(hasImplicitDestinationType);
+  REGISTER_MATCHER(hasInClassInitializer);
   REGISTER_MATCHER(hasIncrement);
   REGISTER_MATCHER(hasIndex);
   REGISTER_MATCHER(hasInitializer);
   REGISTER_MATCHER(hasKeywordSelector);
   REGISTER_MATCHER(hasLHS);
   REGISTER_MATCHER(hasLocalQualifiers);
   REGISTER_MATCHER(hasLocalStorage);
   REGISTER_MATCHER(hasLoopInit);

cfe/trunk/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp

TEST(Member, BitFields) {
   EXPECT_TRUE(matches("class C { int a : 2; int b; };",
                       fieldDecl(isBitField(), hasName("a"))));
   EXPECT_TRUE(notMatches("class C { int a : 2; int b; };",
                          fieldDecl(isBitField(), hasName("b"))));
   EXPECT_TRUE(matches("class C { int a : 2; int b : 4; };",
                       fieldDecl(isBitField(), hasBitWidth(2), hasName("a"))));
 }
 
+TEST(Member, InClassInitializer) {
+  EXPECT_TRUE(
+      matches("class C { int a = 2; int b; };",
+              fieldDecl(hasInClassInitializer(integerLiteral(equals(2))),
+                        hasName("a"))));
+  EXPECT_TRUE(
+      notMatches("class C { int a = 2; int b; };",
+                 fieldDecl(hasInClassInitializer(anything()), hasName("b"))));
+}
+
 TEST(Member, UnderstandsAccess) {
   EXPECT_TRUE(matches(
     "struct A { int i; };", fieldDecl(isPublic(), hasName("i"))));
   EXPECT_TRUE(notMatches(
     "struct A { int i; };", fieldDecl(isProtected(), hasName("i"))));
   EXPECT_TRUE(notMatches(
     "struct A { int i; };", fieldDecl(isPrivate(), hasName("i"))));