ASTMatchers: Add a matcher to detect whether a decl or stmt is inside a template instantiation.

This is hoisted from clang-tidy where it's used everywhere. The implementation
is not particularly efficient right now, but there is no easy fix for that.

Differential Revision: http://reviews.llvm.org/D5085

llvm-svn: 217029

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -2967,6 +2967,46 @@ AST_POLYMORPHIC_MATCHER(
           TSK_ExplicitInstantiationDefinition);
 }
 
+/// \brief Matches declarations that are template instantiations or are inside
+/// template instantiations.
+///
+/// Given
+/// \code
+///   template<typename T> void A(T t) { T i; }
+///   A(0);
+///   A(0U);
+/// \endcode
+/// functionDecl(isInstantiated())
+///   matches 'A(int) {...};' and 'A(unsigned) {...}'.
+AST_MATCHER(Decl, isInstantiated) {
+  auto IsInstantiation = decl(anyOf(recordDecl(isTemplateInstantiation()),
+                                    functionDecl(isTemplateInstantiation())));
+  auto InnerMatcher =
+      decl(anyOf(IsInstantiation, hasAncestor(IsInstantiation)));
+  return InnerMatcher.matches(Node, Finder, Builder);
+}
+
+/// \brief Matches statements inside of a template instantiation.
+///
+/// Given
+/// \code
+///   int j;
+///   template<typename T> void A(T t) { T i; j += 42;}
+///   A(0);
+///   A(0U);
+/// \endcode
+/// declStmt(isInTemplateInstantiation())
+///   matches 'int i;' and 'unsigned i'.
+/// unless(stmt(isInTemplateInstantiation()))
+///   will NOT match j += 42; as it's shared between the template definition and
+///   instantiation.
+AST_MATCHER(Stmt, isInTemplateInstantiation) {
+  auto InnerMatcher =
+      stmt(hasAncestor(decl(anyOf(recordDecl(isTemplateInstantiation()),
+                                  functionDecl(isTemplateInstantiation())))));
+  return InnerMatcher.matches(Node, Finder, Builder);
+}
+
 /// \brief Matches explicit template specializations of function, class, or
 /// static member variable template instantiations.
 ///

clang/lib/ASTMatchers/Dynamic/Registry.cpp

@@ -241,7 +241,9 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(isExpr);
   REGISTER_MATCHER(isExternC);
   REGISTER_MATCHER(isImplicit);
+  REGISTER_MATCHER(isInstantiated);
   REGISTER_MATCHER(isInteger);
+  REGISTER_MATCHER(isInTemplateInstantiation);
   REGISTER_MATCHER(isListInitialization);
   REGISTER_MATCHER(isOverride);
   REGISTER_MATCHER(isPrivate);

clang/unittests/ASTMatchers/ASTMatchersTest.cpp

@@ -3504,6 +3504,62 @@ TEST(IsTemplateInstantiation, DoesNotMatchNonTemplate) {
       recordDecl(isTemplateInstantiation())));
 }
 
+TEST(IsInstantiated, MatchesInstantiation) {
+  EXPECT_TRUE(
+      matches("template<typename T> class A { T i; }; class Y { A<int> a; };",
+              recordDecl(isInstantiated())));
+}
+
+TEST(IsInstantiated, NotMatchesDefinition) {
+  EXPECT_TRUE(notMatches("template<typename T> class A { T i; };",
+                         recordDecl(isInstantiated())));
+}
+
+TEST(IsInTemplateInstantiation, MatchesInstantiationStmt) {
+  EXPECT_TRUE(matches("template<typename T> struct A { A() { T i; } };"
+                      "class Y { A<int> a; }; Y y;",
+                      declStmt(isInTemplateInstantiation())));
+}
+
+TEST(IsInTemplateInstantiation, NotMatchesDefinitionStmt) {
+  EXPECT_TRUE(notMatches("template<typename T> struct A { void x() { T i; } };",
+                         declStmt(isInTemplateInstantiation())));
+}
+
+TEST(IsInstantiated, MatchesFunctionInstantiation) {
+  EXPECT_TRUE(
+      matches("template<typename T> void A(T t) { T i; } void x() { A(0); }",
+              functionDecl(isInstantiated())));
+}
+
+TEST(IsInstantiated, NotMatchesFunctionDefinition) {
+  EXPECT_TRUE(notMatches("template<typename T> void A(T t) { T i; }",
+                         varDecl(isInstantiated())));
+}
+
+TEST(IsInTemplateInstantiation, MatchesFunctionInstantiationStmt) {
+  EXPECT_TRUE(
+      matches("template<typename T> void A(T t) { T i; } void x() { A(0); }",
+              declStmt(isInTemplateInstantiation())));
+}
+
+TEST(IsInTemplateInstantiation, NotMatchesFunctionDefinitionStmt) {
+  EXPECT_TRUE(notMatches("template<typename T> void A(T t) { T i; }",
+                         declStmt(isInTemplateInstantiation())));
+}
+
+TEST(IsInTemplateInstantiation, Sharing) {
+  auto Matcher = binaryOperator(unless(isInTemplateInstantiation()));
+  // FIXME: Node sharing is an implementation detail, exposing it is ugly
+  // and makes the matcher behave in non-obvious ways.
+  EXPECT_TRUE(notMatches(
+      "int j; template<typename T> void A(T t) { j += 42; } void x() { A(0); }",
+      Matcher));
+  EXPECT_TRUE(matches(
+      "int j; template<typename T> void A(T t) { j += t; } void x() { A(0); }",
+      Matcher));
+}
+
 TEST(IsExplicitTemplateSpecialization,
      DoesNotMatchPrimaryTemplate) {
   EXPECT_TRUE(notMatches(