Revert AST Matchers default to AsIs mode

[steveire]

Update

[steveire]

Update

[klimek]

lg

[aaron.ballman]

LG, but should this also update the release notes to remove the mention about the new default?

clang-tools-extra/clang-query/Query.cpp

OS << "Available commands:\n\n"
         "as part of other expressions.\n"
         "  set bind-root (true|false)        "
         "Set whether to bind the root matcher to \"root\".\n"
         "  set print-matcher (true|false)    "
         "Set whether to print the current matcher,\n"
         "  set traversal <kind>              "
         "Set traversal kind of clang-query session. Available kinds are:\n"
         "    AsIs                            "
-        "Print and match the AST as clang sees it.\n"
+        "Print and match the AST as clang sees it.  This mode is the "
+        "default.\n"
         "    IgnoreImplicitCastsAndParentheses  "
         "Omit implicit casts and parens in matching and dumping.\n"
         "    IgnoreUnlessSpelledInSource     "
-        "Omit AST nodes unless spelled in the source.  This mode is the "
-        "default.\n"
+        "Omit AST nodes unless spelled in the source.\n"
         "  set output <feature>              "
         "Set whether to output only <feature> content.\n"
         "  enable output <feature>           "
         "Enable <feature> content non-exclusively.\n"
         "  disable output <feature>          "
         "Disable <feature> content non-exclusively.\n"
         "  quit, q                           "
         "Terminates the query session.\n\n"

clang-tools-extra/clang-query/QuerySession.h

 namespace query {
 
 /// Represents the state for a particular clang-query session.
 class QuerySession {
 public:
   QuerySession(llvm::ArrayRef<std::unique_ptr<ASTUnit>> ASTs)
       : ASTs(ASTs), PrintOutput(false), DiagOutput(true),
         DetailedASTOutput(false), BindRoot(true), PrintMatcher(false),
-        Terminate(false), TK(ast_type_traits::TK_IgnoreUnlessSpelledInSource) {}
+        Terminate(false), TK(ast_type_traits::TK_AsIs) {}
 
   llvm::ArrayRef<std::unique_ptr<ASTUnit>> ASTs;
 
   bool PrintOutput;
   bool DiagOutput;
   bool DetailedASTOutput;
 
   bool BindRoot;

clang/include/clang/AST/ParentMapContext.h

public:
 
   const Expr *traverseIgnored(const Expr *E) const;
   Expr *traverseIgnored(Expr *E) const;
   DynTypedNode traverseIgnored(const DynTypedNode &N) const;
 
 private:
   ASTContext &ASTCtx;
   class ParentMap;
-  TraversalKind Traversal = TK_IgnoreUnlessSpelledInSource;
+  TraversalKind Traversal = TK_AsIs;
   std::unique_ptr<ParentMap> Parents;
 };
 
 class TraversalKindScope {
   ParentMapContext &Ctx;
   TraversalKind TK = TK_AsIs;
 
 public:

clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp

TEST_P(ASTMatchersTest, CastExpression_MatchesImplicitCasts) {
   EXPECT_TRUE(
       matches("char c = 0;", traverse(ast_type_traits::TK_AsIs, castExpr())));
   // This test creates an implicit cast from lvalue to rvalue.
   EXPECT_TRUE(matches("void f() { char c = 0, d = c; }",
                       traverse(ast_type_traits::TK_AsIs, castExpr())));
 }
 
 TEST_P(ASTMatchersTest, CastExpr_DoesNotMatchNonCasts) {
+  if (GetParam().Language == Lang_C89 || GetParam().Language == Lang_C99) {
+    // This does have a cast in C
+    EXPECT_TRUE(matches("char c = '0';", implicitCastExpr()));
+  } else {
     EXPECT_TRUE(notMatches("char c = '0';", castExpr()));
+  }
   EXPECT_TRUE(notMatches("int i = (0);", castExpr()));
   EXPECT_TRUE(notMatches("int i = 0;", castExpr()));
 }
 
 TEST_P(ASTMatchersTest, CastExpr_DoesNotMatchNonCasts_CXX) {
   if (!GetParam().isCXX()) {
     return;
   }