[libclang] Add missing header file

llvm-svn: 172090

clang/tools/libclang/CLog.h

@@ -0,0 +1,95 @@
+//===- CLog.h - Logging Interface -------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBCLANG_CLOG_H
+#define LLVM_LIBCLANG_CLOG_H
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/IntrusiveRefCntPtr.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/raw_ostream.h"
+#include <string>
+
+namespace llvm {
+class format_object_base;
+}
+
+namespace clang {
+
+namespace cxindex {
+
+class Logger;
+typedef IntrusiveRefCntPtr<Logger> LogRef;
+
+/// \brief Collects logging output and writes it to stderr when it's destructed.
+/// Common use case:
+/// \code
+///   if (LogRef Log = Logger::make(__func__)) {
+///     *Log << "stuff";
+///   }
+/// \endcode
+class Logger : public RefCountedBase<Logger> {
+  std::string Name;
+  bool Trace;
+  llvm::SmallString<64> Msg;
+  llvm::raw_svector_ostream LogOS;
+public:
+  static const char *getEnvVar() {
+    static const char *sCachedVar = ::getenv("LIBCLANG_LOGGING");
+    return sCachedVar;
+  }
+  static bool isLoggingEnabled() { return getEnvVar() != 0; }
+  static bool isStackTracingEnabled() {
+    if (const char *EnvOpt = Logger::getEnvVar())
+      return llvm::StringRef(EnvOpt) =="2";
+    return false;
+  }
+  static LogRef make(llvm::StringRef name,
+                     bool trace = isStackTracingEnabled()) {
+    if (isLoggingEnabled())
+      return new Logger(name, trace);
+    return 0;
+  }
+
+  explicit Logger(llvm::StringRef name, bool trace)
+    : Name(name), Trace(trace), LogOS(Msg) { }
+  ~Logger();
+
+  Logger &operator<<(CXTranslationUnit);
+  Logger &operator<<(CXSourceLocation);
+  Logger &operator<<(CXSourceRange);
+  Logger &operator<<(CXString);
+  Logger &operator<<(llvm::StringRef Str) { LogOS << Str; return *this; }
+  Logger &operator<<(const char *Str) {
+    if (Str)
+      LogOS << Str;
+    return *this;
+  }
+  Logger &operator<<(unsigned long N) { LogOS << N; return *this; }
+  Logger &operator<<(long N) { LogOS << N ; return *this; }
+  Logger &operator<<(unsigned int N) { LogOS << N; return *this; }
+  Logger &operator<<(int N) { LogOS << N; return *this; }
+  Logger &operator<<(char C) { LogOS << C; return *this; }
+  Logger &operator<<(unsigned char C) { LogOS << C; return *this; }
+  Logger &operator<<(signed char C) { LogOS << C; return *this; }
+  Logger &operator<<(const llvm::format_object_base &Fmt);
+};
+
+}
+}
+
+/// \brief Macros to automate common uses of Logger. Like this:
+/// \code
+///   LOG_FUNC_SECTION {
+///     *Log << "blah";
+///   }
+#define LOG_SECTION(NAME) if (LogRef Log = clang::cxindex::Logger::make(NAME))
+#define LOG_FUNC_SECTION LOG_SECTION(__func__)
+
+#endif