CLog.h revision cfa88f893915ceb8ae4ce2f17c46c24a4d67502f 
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 "llvm/ADT/IntrusiveRefCntPtr.h"
14#include "llvm/ADT/SmallString.h"
15#include "llvm/ADT/StringRef.h"
16#include "llvm/Support/Compiler.h"
17#include "llvm/Support/raw_ostream.h"
18#include <string>
19
20namespace llvm {
21class format_object_base;
22}
23
24namespace clang {
25
26namespace cxindex {
27
28class Logger;
29typedef IntrusiveRefCntPtr<Logger> LogRef;
30
31/// \brief Collects logging output and writes it to stderr when it's destructed.
32/// Common use case:
33/// \code
34///   if (LogRef Log = Logger::make(__func__)) {
35///     *Log << "stuff";
36///   }
37/// \endcode
38class Logger : public RefCountedBase<Logger> {
39  std::string Name;
40  bool Trace;
41  SmallString<64> Msg;
42  llvm::raw_svector_ostream LogOS;
43public:
44  static const char *getEnvVar() {
45    static const char *sCachedVar = ::getenv("LIBCLANG_LOGGING");
46    return sCachedVar;
47  }
48  static bool isLoggingEnabled() { return getEnvVar() != 0; }
49  static bool isStackTracingEnabled() {
50    if (const char *EnvOpt = Logger::getEnvVar())
51      return llvm::StringRef(EnvOpt) == "2";
52    return false;
53  }
54  static LogRef make(llvm::StringRef name,
55                     bool trace = isStackTracingEnabled()) {
56    if (isLoggingEnabled())
57      return new Logger(name, trace);
58    return 0;
59  }
60
61  explicit Logger(llvm::StringRef name, bool trace)
62    : Name(name), Trace(trace), LogOS(Msg) { }
63  ~Logger();
64
65  Logger &operator<<(CXTranslationUnit);
66  Logger &operator<<(CXSourceLocation);
67  Logger &operator<<(CXSourceRange);
68  Logger &operator<<(CXString);
69  Logger &operator<<(llvm::StringRef Str) { LogOS << Str; return *this; }
70  Logger &operator<<(const char *Str) {
71    if (Str)
72      LogOS << Str;
73    return *this;
74  }
75  Logger &operator<<(unsigned long N) { LogOS << N; return *this; }
76  Logger &operator<<(long N) { LogOS << N ; return *this; }
77  Logger &operator<<(unsigned int N) { LogOS << N; return *this; }
78  Logger &operator<<(int N) { LogOS << N; return *this; }
79  Logger &operator<<(char C) { LogOS << C; return *this; }
80  Logger &operator<<(unsigned char C) { LogOS << C; return *this; }
81  Logger &operator<<(signed char C) { LogOS << C; return *this; }
82  Logger &operator<<(const llvm::format_object_base &Fmt);
83};
84
85}
86}
87
88/// \brief Macros to automate common uses of Logger. Like this:
89/// \code
90///   LOG_FUNC_SECTION {
91///     *Log << "blah";
92///   }
93/// \endcode
94#define LOG_SECTION(NAME) if (LogRef Log = clang::cxindex::Logger::make(NAME))
95#define LOG_FUNC_SECTION LOG_SECTION(LLVM_FUNCTION_NAME)
96
97#endif
98