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-c/Index.h"
14#include "clang/Basic/LLVM.h"
15#include "llvm/ADT/IntrusiveRefCntPtr.h"
16#include "llvm/ADT/SmallString.h"
17#include "llvm/ADT/StringRef.h"
18#include "llvm/Support/Compiler.h"
19#include "llvm/Support/raw_ostream.h"
20#include <string>
21
22namespace llvm {
23class format_object_base;
24}
25
26namespace clang {
27  class FileEntry;
28
29namespace cxindex {
30
31class Logger;
32typedef IntrusiveRefCntPtr<Logger> LogRef;
33
34/// \brief Collects logging output and writes it to stderr when it's destructed.
35/// Common use case:
36/// \code
37///   if (LogRef Log = Logger::make(__func__)) {
38///     *Log << "stuff";
39///   }
40/// \endcode
41class Logger : public RefCountedBase<Logger> {
42  std::string Name;
43  bool Trace;
44  SmallString<64> Msg;
45  llvm::raw_svector_ostream LogOS;
46public:
47  static const char *getEnvVar() {
48    static const char *sCachedVar = ::getenv("LIBCLANG_LOGGING");
49    return sCachedVar;
50  }
51  static bool isLoggingEnabled() { return getEnvVar() != nullptr; }
52  static bool isStackTracingEnabled() {
53    if (const char *EnvOpt = Logger::getEnvVar())
54      return llvm::StringRef(EnvOpt) == "2";
55    return false;
56  }
57  static LogRef make(llvm::StringRef name,
58                     bool trace = isStackTracingEnabled()) {
59    if (isLoggingEnabled())
60      return new Logger(name, trace);
61    return nullptr;
62  }
63
64  explicit Logger(llvm::StringRef name, bool trace)
65    : Name(name), Trace(trace), LogOS(Msg) { }
66  ~Logger();
67
68  Logger &operator<<(CXTranslationUnit);
69  Logger &operator<<(const FileEntry *FE);
70  Logger &operator<<(CXCursor cursor);
71  Logger &operator<<(CXSourceLocation);
72  Logger &operator<<(CXSourceRange);
73  Logger &operator<<(CXString);
74  Logger &operator<<(llvm::StringRef Str) { LogOS << Str; return *this; }
75  Logger &operator<<(const char *Str) {
76    if (Str)
77      LogOS << Str;
78    return *this;
79  }
80  Logger &operator<<(unsigned long N) { LogOS << N; return *this; }
81  Logger &operator<<(long N) { LogOS << N ; return *this; }
82  Logger &operator<<(unsigned int N) { LogOS << N; return *this; }
83  Logger &operator<<(int N) { LogOS << N; return *this; }
84  Logger &operator<<(char C) { LogOS << C; return *this; }
85  Logger &operator<<(unsigned char C) { LogOS << C; return *this; }
86  Logger &operator<<(signed char C) { LogOS << C; return *this; }
87  Logger &operator<<(const llvm::format_object_base &Fmt);
88};
89
90}
91}
92
93/// \brief Macros to automate common uses of Logger. Like this:
94/// \code
95///   LOG_FUNC_SECTION {
96///     *Log << "blah";
97///   }
98/// \endcode
99#define LOG_SECTION(NAME) \
100    if (clang::cxindex::LogRef Log = clang::cxindex::Logger::make(NAME))
101#define LOG_FUNC_SECTION LOG_SECTION(LLVM_FUNCTION_NAME)
102
103#endif
104