Update RecursiveASTVisitor so that it visits attributes. This is currently

important for thread safety attributes, which contain expressions that were
not being visited, and were thus invisible to various tools.  There are now
Visit*Attr methods that can be overridden for every attribute.

llvm-svn: 198224

clang/include/clang/AST/CMakeLists.txt

@@ -13,6 +13,11 @@ clang_tablegen(AttrDump.inc -gen-clang-attr-dump
   SOURCE ../Basic/Attr.td
   TARGET ClangAttrDump)
 
+clang_tablegen(AttrVisitor.inc -gen-clang-attr-ast-visitor
+  -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
+  SOURCE ../Basic/Attr.td
+  TARGET ClangAttrVisitor)
+
 clang_tablegen(StmtNodes.inc -gen-clang-stmt-nodes
   SOURCE ../Basic/StmtNodes.td
   TARGET ClangStmtNodes)

clang/include/clang/AST/Makefile

@@ -1,6 +1,6 @@
 CLANG_LEVEL := ../../..
 TD_SRC_DIR = $(PROJ_SRC_DIR)/../Basic
-BUILT_SOURCES = Attrs.inc AttrImpl.inc AttrDump.inc \
+BUILT_SOURCES = Attrs.inc AttrImpl.inc AttrDump.inc AttrVisitor.inc \
                 StmtNodes.inc DeclNodes.inc \
                 CommentNodes.inc CommentHTMLTags.inc \
                 CommentHTMLTagsProperties.inc \
@@ -30,6 +30,12 @@ $(ObjDir)/AttrDump.inc.tmp : $(TD_SRC_DIR)/Attr.td $(CLANG_TBLGEN) \
 	$(Verb) $(ClangTableGen) -gen-clang-attr-dump -o $(call SYSPATH, $@) \
 		-I $(PROJ_SRC_DIR)/../../ $<
 
+$(ObjDir)/AttrVisitor.inc.tmp : $(TD_SRC_DIR)/Attr.td $(CLANG_TBLGEN) \
+                                $(ObjDir)/.dir
+	$(Echo) "Building Clang attribute AST visitor with tblgen"
+	$(Verb) $(ClangTableGen) -gen-clang-attr-ast-visitor -o $(call SYSPATH, $@) \
+		-I $(PROJ_SRC_DIR)/../../ $<
+
 $(ObjDir)/StmtNodes.inc.tmp : $(TD_SRC_DIR)/StmtNodes.td $(CLANG_TBLGEN) \
                               $(ObjDir)/.dir
 	$(Echo) "Building Clang statement node tables with tblgen"

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -14,6 +14,7 @@
 #ifndef LLVM_CLANG_AST_RECURSIVEASTVISITOR_H
 #define LLVM_CLANG_AST_RECURSIVEASTVISITOR_H
 
+#include "clang/AST/Attr.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclFriend.h"
@@ -182,6 +183,13 @@ public:
   /// otherwise (including when the argument is a Null type location).
   bool TraverseTypeLoc(TypeLoc TL);
 
+  /// \brief Recursively visit an attribute, by dispatching to
+  /// Traverse*Attr() based on the argument's dynamic type.
+  ///
+  /// \returns false if the visitation was terminated early, true
+  /// otherwise (including when the argument is a Null type location).
+  bool TraverseAttr(Attr *At);
+
   /// \brief Recursively visit a declaration, by dispatching to
   /// Traverse*Decl() based on the argument's dynamic type.
   ///
@@ -254,6 +262,16 @@ public:
   /// \returns false if the visitation was terminated early, true otherwise.
   bool TraverseLambdaBody(LambdaExpr *LE);
 
+  // ---- Methods on Attrs ----
+
+  // \brief Visit an attribute.
+  bool VisitAttr(Attr *A) { return true; }
+
+  // Declare Traverse* and empty Visit* for all Attr classes.
+#define ATTR_VISITOR_DECLS_ONLY
+#include "clang/AST/AttrVisitor.inc"
+#undef ATTR_VISITOR_DECLS_ONLY
+
   // ---- Methods on Stmts ----
 
   // Declare Traverse*() for all concrete Stmt classes.
@@ -623,6 +641,10 @@ bool RecursiveASTVisitor<Derived>::TraverseTypeLoc(TypeLoc TL) {
 }
 
 
+// Define the Traverse*Attr(Attr* A) methods
+#include "clang/AST/AttrVisitor.inc"
+
+
 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseDecl(Decl *D) {
   if (!D)
@@ -636,10 +658,18 @@ bool RecursiveASTVisitor<Derived>::TraverseDecl(Decl *D) {
   switch (D->getKind()) {
 #define ABSTRACT_DECL(DECL)
 #define DECL(CLASS, BASE) \
-  case Decl::CLASS: DISPATCH(CLASS##Decl, CLASS##Decl, D);
+  case Decl::CLASS: \
+    if (!getDerived().Traverse##CLASS##Decl(static_cast<CLASS##Decl*>(D))) \
+      return false; \
+    break;
 #include "clang/AST/DeclNodes.inc"
   }
 
+  // Visit any attributes attached to this declaration.
+  for (Decl::attr_iterator I=D->attr_begin(), E=D->attr_end(); I != E; ++I) {
+    if (!getDerived().TraverseAttr(*I))
+      return false;
+  }
   return true;
 }
 

clang/lib/AST/CMakeLists.txt

@@ -65,6 +65,7 @@ add_dependencies(clangAST
   ClangAttrList
   ClangAttrImpl
   ClangAttrDump
+  ClangAttrVisitor
   ClangCommentCommandInfo
   ClangCommentCommandList
   ClangCommentNodes

clang/unittests/Tooling/RecursiveASTVisitorTest.cpp

@@ -577,4 +577,43 @@ TEST(RecursiveASTVisitor, LambdaClosureTypesAreImplicit) {
   EXPECT_TRUE(Visitor.sawOnlyImplicitLambdaClasses());
 }
 
+
+
+// Check to ensure that attributes and expressions within them are being
+// visited.
+class AttrVisitor : public ExpectedLocationVisitor<AttrVisitor> {
+public:
+  bool VisitMemberExpr(MemberExpr *ME) {
+    Match(ME->getMemberDecl()->getNameAsString(), ME->getLocStart());
+    return true;
+  }
+  bool VisitAttr(Attr *A) {
+    Match("Attr", A->getLocation());
+    return true;
+  }
+  bool VisitGuardedByAttr(GuardedByAttr *A) {
+    Match("guarded_by", A->getLocation());
+    return true;
+  }
+};
+
+
+TEST(RecursiveASTVisitor, AttributesAreVisited) {
+  AttrVisitor Visitor;
+  Visitor.ExpectMatch("Attr", 4, 24);
+  Visitor.ExpectMatch("guarded_by", 4, 24);
+  Visitor.ExpectMatch("mu1",  4, 35);
+  Visitor.ExpectMatch("Attr", 5, 29);
+  Visitor.ExpectMatch("mu1",  5, 54);
+  Visitor.ExpectMatch("mu2",  5, 59);
+  EXPECT_TRUE(Visitor.runOver(
+    "class Foo {\n"
+    "  int mu1;\n"
+    "  int mu2;\n"
+    "  int a __attribute__((guarded_by(mu1)));\n"
+    "  void bar() __attribute__((exclusive_locks_required(mu1, mu2)));\n"
+    "};\n"));
+}
+
+
 } // end namespace clang

clang/utils/TableGen/ClangAttrEmitter.cpp

@@ -149,6 +149,7 @@ namespace {
     // These functions print the argument contents formatted in different ways.
     virtual void writeAccessors(raw_ostream &OS) const = 0;
     virtual void writeAccessorDefinitions(raw_ostream &OS) const {}
+    virtual void writeASTVisitorTraversal(raw_ostream &OS) const {}
     virtual void writeCloneArgs(raw_ostream &OS) const = 0;
     virtual void writeTemplateInstantiationArgs(raw_ostream &OS) const = 0;
     virtual void writeTemplateInstantiation(raw_ostream &OS) const {}
@@ -794,6 +795,12 @@ namespace {
       : SimpleArgument(Arg, Attr, "Expr *")
     {}
 
+    virtual void writeASTVisitorTraversal(raw_ostream &OS) const {
+      OS << "  if (!"
+         << "getDerived().TraverseStmt(A->get" << getUpperName() << "()))\n";
+      OS << "    return false;\n";
+    }
+
     void writeTemplateInstantiationArgs(raw_ostream &OS) const {
       OS << "tempInst" << getUpperName();
     }
@@ -826,6 +833,19 @@ namespace {
       : VariadicArgument(Arg, Attr, "Expr *")
     {}
 
+    virtual void writeASTVisitorTraversal(raw_ostream &OS) const {
+      OS << "  {\n";
+      OS << "    " << getType() << " *I = A->" << getLowerName()
+         << "_begin();\n";
+      OS << "    " << getType() << " *E = A->" << getLowerName()
+         << "_end();\n";
+      OS << "    for (; I != E; ++I) {\n";
+      OS << "      if (!getDerived().TraverseStmt(*I))\n";
+      OS << "        return false;\n";
+      OS << "    }\n";
+      OS << "  }\n";
+    }
+
     void writeTemplateInstantiationArgs(raw_ostream &OS) const {
       OS << "tempInst" << getUpperName() << ", "
          << "A->" << getLowerName() << "_size()";
@@ -1568,6 +1588,85 @@ void EmitClangAttrSpellingListIndex(RecordKeeper &Records, raw_ostream &OS) {
   OS << "  return 0;\n";
 }
 
+// Emits code used by RecursiveASTVisitor to visit attributes
+void EmitClangAttrASTVisitor(RecordKeeper &Records, raw_ostream &OS) {
+  emitSourceFileHeader("Used by RecursiveASTVisitor to visit attributes.", OS);
+
+  std::vector<Record*> Attrs = Records.getAllDerivedDefinitions("Attr");
+
+  // Write method declarations for Traverse* methods.
+  // We emit this here because we only generate methods for attributes that
+  // are declared as ASTNodes.
+  OS << "#ifdef ATTR_VISITOR_DECLS_ONLY\n\n";
+  for (std::vector<Record*>::iterator I = Attrs.begin(), E = Attrs.end();
+       I != E; ++I) {
+    Record &R = **I;
+    if (!R.getValueAsBit("ASTNode"))
+      continue;
+    OS << "  bool Traverse"
+       << R.getName() << "Attr(" << R.getName() << "Attr *A);\n";
+    OS << "  bool Visit"
+       << R.getName() << "Attr(" << R.getName() << "Attr *A) {\n"
+       << "    return true; \n"
+       << "  };\n";
+  }
+  OS << "\n#else // ATTR_VISITOR_DECLS_ONLY\n\n";
+
+  // Write individual Traverse* methods for each attribute class.
+  for (std::vector<Record*>::iterator I = Attrs.begin(), E = Attrs.end();
+       I != E; ++I) {
+    Record &R = **I;
+    if (!R.getValueAsBit("ASTNode"))
+      continue;
+
+    OS << "template <typename Derived>\n"
+       << "bool RecursiveASTVisitor<Derived>::Traverse"
+       << R.getName() << "Attr(" << R.getName() << "Attr *A) {\n"
+       << "  if (!getDerived().VisitAttr(A))\n"
+       << "    return false;\n"
+       << "  if (!getDerived().Visit" << R.getName() << "Attr(A))\n"
+       << "    return false;\n";
+
+    std::vector<Record*> ArgRecords = R.getValueAsListOfDefs("Args");
+    for (std::vector<Record*>::iterator ri = ArgRecords.begin(),
+                                        re = ArgRecords.end();
+         ri != re; ++ri) {
+      Record &ArgRecord = **ri;
+      Argument *Arg = createArgument(ArgRecord, R.getName());
+      assert(Arg);
+      Arg->writeASTVisitorTraversal(OS);
+    }
+
+    OS << "  return true;\n";
+    OS << "}\n\n";
+  }
+
+  // Write generic Traverse routine
+  OS << "template <typename Derived>\n"
+     << "bool RecursiveASTVisitor<Derived>::TraverseAttr(Attr *A) {\n"
+     << "  if (!A)\n"
+     << "    return true;\n"
+     << "\n"
+     << "  switch (A->getKind()) {\n"
+     << "    default:\n"
+     << "      return true;\n";
+
+  for (std::vector<Record*>::iterator I = Attrs.begin(), E = Attrs.end();
+       I != E; ++I) {
+    Record &R = **I;
+    if (!R.getValueAsBit("ASTNode"))
+      continue;
+
+    OS << "    case attr::" << R.getName() << ":\n"
+       << "      return getDerived().Traverse" << R.getName() << "Attr("
+       << "cast<" << R.getName() << "Attr>(A));\n";
+  }
+  OS << "  }\n";  // end case
+  OS << "}\n";  // end function
+  OS << "#endif  // ATTR_VISITOR_DECLS_ONLY\n";
+}
+
+
 // Emits the LateParsed property for attributes.
 void EmitClangAttrLateParsedList(RecordKeeper &Records, raw_ostream &OS) {
   emitSourceFileHeader("llvm::StringSwitch code to match late parsed "

clang/utils/TableGen/TableGen.cpp

@@ -32,6 +32,7 @@ enum ActionType {
   GenClangAttrPCHWrite,
   GenClangAttrSpellingList,
   GenClangAttrSpellingListIndex,
+  GenClangAttrASTVisitor,
   GenClangAttrLateParsedList,
   GenClangAttrTemplateInstantiate,
   GenClangAttrParsedAttrList,
@@ -82,6 +83,9 @@ cl::opt<ActionType> Action(
         clEnumValN(GenClangAttrSpellingListIndex,
                    "gen-clang-attr-spelling-index",
                    "Generate a clang attribute spelling index"),
+        clEnumValN(GenClangAttrASTVisitor,
+                   "gen-clang-attr-ast-visitor",
+                   "Generate a recursive AST visitor for clang attributes"),
         clEnumValN(GenClangAttrLateParsedList,
                    "gen-clang-attr-late-parsed-list",
                    "Generate a clang attribute LateParsed list"),
@@ -171,6 +175,9 @@ bool ClangTableGenMain(raw_ostream &OS, RecordKeeper &Records) {
   case GenClangAttrSpellingListIndex:
     EmitClangAttrSpellingListIndex(Records, OS);
     break;
+  case GenClangAttrASTVisitor:
+    EmitClangAttrASTVisitor(Records, OS);
+    break;
   case GenClangAttrLateParsedList:
     EmitClangAttrLateParsedList(Records, OS);
     break;

clang/utils/TableGen/TableGenBackends.h

@@ -38,6 +38,7 @@ void EmitClangAttrPCHRead(RecordKeeper &Records, raw_ostream &OS);
 void EmitClangAttrPCHWrite(RecordKeeper &Records, raw_ostream &OS);
 void EmitClangAttrSpellingList(RecordKeeper &Records, raw_ostream &OS);
 void EmitClangAttrSpellingListIndex(RecordKeeper &Records, raw_ostream &OS);
+void EmitClangAttrASTVisitor(RecordKeeper &Records, raw_ostream &OS);
 void EmitClangAttrLateParsedList(RecordKeeper &Records, raw_ostream &OS);
 void EmitClangAttrTemplateInstantiate(RecordKeeper &Records, raw_ostream &OS);
 void EmitClangAttrParsedAttrList(RecordKeeper &Records, raw_ostream &OS);