Introduce clang-query tool.

This tool is for interactive exploration of the Clang AST using AST matchers.
It currently allows the user to enter a matcher at an interactive prompt
and view the resulting bindings as diagnostics, AST pretty prints or AST
dumps. Example session:

$ cat foo.c
void foo(void) {}
$ clang-query foo.c --
clang-query> match functionDecl()

Match #1:

foo.c:1:1: note: "root" binds here
void foo(void) {}
^~~~~~~~~~~~~~~~~
1 match.

Differential Revision: http://llvm-reviews.chandlerc.com/D2098

llvm-svn: 194227

1 files changed, 36 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-query/QuerySession.h b/clang-tools-extra/clang-query/QuerySession.h
new file mode 100644
index 00000000000..002b2b56db5
--- /dev/null
+++ b/clang-tools-extra/clang-query/QuerySession.h
@@ -0,0 +1,36 @@
+//===--- QuerySession.h - clang-query ---------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_QUERY_QUERY_SESSION_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_QUERY_QUERY_SESSION_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "Query.h"
+
+namespace clang {
+
+class ASTUnit;
+
+namespace query {
+
+/// Represents the state for a particular clang-query session.
+class QuerySession {
+public:
+  QuerySession(llvm::ArrayRef<ASTUnit *> ASTs)
+      : ASTs(ASTs), OutKind(OK_Diag), BindRoot(true) {}
+
+  llvm::ArrayRef<ASTUnit *> ASTs;
+  OutputKind OutKind;
+  bool BindRoot;
+};
+
+} // namespace query
+} // namespace clang
+
+#endif