CLog.h revision b1ba0efc3d1dc1daa5d82c40bc504e1f368c4fa0 
1//===- CLog.h - Logging Interface -------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef LLVM_LIBCLANG_CLOG_H
11#define LLVM_LIBCLANG_CLOG_H
12
13#include "clang/Basic/LLVM.h"
14#include "llvm/ADT/IntrusiveRefCntPtr.h"
15#include "llvm/ADT/SmallString.h"
16#include "llvm/ADT/StringRef.h"
17#include "llvm/Support/Compiler.h"
18#include "llvm/Support/raw_ostream.h"
19#include <string>
20
21namespace llvm {
22class format_object_base;
23}
24
25namespace clang {
26
27namespace cxindex {
28
29class Logger;
30typedef IntrusiveRefCntPtr<Logger> LogRef;
31
32/// \brief Collects logging output and writes it to stderr when it's destructed.
33/// Common use case:
34/// \code
35///   if (LogRef Log = Logger::make(__func__)) {
36///     *Log << "stuff";
37///   }
38/// \endcode
39class Logger : public RefCountedBase<Logger> {
40  std::string Name;
41  bool Trace;
42  SmallString<64> Msg;
43  llvm::raw_svector_ostream LogOS;
44public:
45  static const char *getEnvVar() {
46    static const char *sCachedVar = ::getenv("LIBCLANG_LOGGING");
47    return sCachedVar;
48  }
49  static bool isLoggingEnabled() { return getEnvVar() != 0; }
50  static bool isStackTracingEnabled() {
51    if (const char *EnvOpt = Logger::getEnvVar())
52      return llvm::StringRef(EnvOpt) == "2";
53    return false;
54  }
55  static LogRef make(llvm::StringRef name,
56                     bool trace = isStackTracingEnabled()) {
57    if (isLoggingEnabled())
58      return new Logger(name, trace);
59    return 0;
60  }
61
62  explicit Logger(llvm::StringRef name, bool trace)
63    : Name(name), Trace(trace), LogOS(Msg) { }
64  ~Logger();
65
66  Logger &operator<<(CXTranslationUnit);
67  Logger &operator<<(CXSourceLocation);
68  Logger &operator<<(CXSourceRange);
69  Logger &operator<<(CXString);
70  Logger &operator<<(llvm::StringRef Str) { LogOS << Str; return *this; }
71  Logger &operator<<(const char *Str) {
72    if (Str)
73      LogOS << Str;
74    return *this;
75  }
76  Logger &operator<<(unsigned long N) { LogOS << N; return *this; }
77  Logger &operator<<(long N) { LogOS << N ; return *this; }
78  Logger &operator<<(unsigned int N) { LogOS << N; return *this; }
79  Logger &operator<<(int N) { LogOS << N; return *this; }
80  Logger &operator<<(char C) { LogOS << C; return *this; }
81  Logger &operator<<(unsigned char C) { LogOS << C; return *this; }
82  Logger &operator<<(signed char C) { LogOS << C; return *this; }
83  Logger &operator<<(const llvm::format_object_base &Fmt);
84};
85
86}
87}
88
89/// \brief Macros to automate common uses of Logger. Like this:
90/// \code
91///   LOG_FUNC_SECTION {
92///     *Log << "blah";
93///   }
94/// \endcode
95#define LOG_SECTION(NAME) if (LogRef Log = clang::cxindex::Logger::make(NAME))
96#define LOG_FUNC_SECTION LOG_SECTION(LLVM_FUNCTION_NAME)
97
98#endif
99