CLog.h revision d8d9b847bd7120ebd5be83a55d31d9c26142962e 
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/StringRef.h"
14#include "llvm/ADT/IntrusiveRefCntPtr.h"
15#include "llvm/ADT/SmallString.h"
16#include "llvm/Support/raw_ostream.h"
17#include <string>
18
19namespace llvm {
20class format_object_base;
21}
22
23namespace clang {
24
25namespace cxindex {
26
27class Logger;
28typedef IntrusiveRefCntPtr<Logger> LogRef;
29
30/// \brief Collects logging output and writes it to stderr when it's destructed.
31/// Common use case:
32/// \code
33///   if (LogRef Log = Logger::make(__func__)) {
34///     *Log << "stuff";
35///   }
36/// \endcode
37class Logger : public RefCountedBase<Logger> {
38  std::string Name;
39  bool Trace;
40  llvm::SmallString<64> Msg;
41  llvm::raw_svector_ostream LogOS;
42public:
43  static const char *getEnvVar() {
44    static const char *sCachedVar = ::getenv("LIBCLANG_LOGGING");
45    return sCachedVar;
46  }
47  static bool isLoggingEnabled() { return getEnvVar() != 0; }
48  static bool isStackTracingEnabled() {
49    if (const char *EnvOpt = Logger::getEnvVar())
50      return llvm::StringRef(EnvOpt) =="2";
51    return false;
52  }
53  static LogRef make(llvm::StringRef name,
54                     bool trace = isStackTracingEnabled()) {
55    if (isLoggingEnabled())
56      return new Logger(name, trace);
57    return 0;
58  }
59
60  explicit Logger(llvm::StringRef name, bool trace)
61    : Name(name), Trace(trace), LogOS(Msg) { }
62  ~Logger();
63
64  Logger &operator<<(CXTranslationUnit);
65  Logger &operator<<(CXSourceLocation);
66  Logger &operator<<(CXSourceRange);
67  Logger &operator<<(CXString);
68  Logger &operator<<(llvm::StringRef Str) { LogOS << Str; return *this; }
69  Logger &operator<<(const char *Str) {
70    if (Str)
71      LogOS << Str;
72    return *this;
73  }
74  Logger &operator<<(unsigned long N) { LogOS << N; return *this; }
75  Logger &operator<<(long N) { LogOS << N ; return *this; }
76  Logger &operator<<(unsigned int N) { LogOS << N; return *this; }
77  Logger &operator<<(int N) { LogOS << N; return *this; }
78  Logger &operator<<(char C) { LogOS << C; return *this; }
79  Logger &operator<<(unsigned char C) { LogOS << C; return *this; }
80  Logger &operator<<(signed char C) { LogOS << C; return *this; }
81  Logger &operator<<(const llvm::format_object_base &Fmt);
82};
83
84}
85}
86
87/// \brief Macros to automate common uses of Logger. Like this:
88/// \code
89///   LOG_FUNC_SECTION {
90///     *Log << "blah";
91///   }
92#define LOG_SECTION(NAME) if (LogRef Log = clang::cxindex::Logger::make(NAME))
93#define LOG_FUNC_SECTION LOG_SECTION(__func__)
94
95#endif
96