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 
21 namespace llvm {
22 class format_object_base;
23 }
24 
25 namespace clang {
26   class FileEntry;
27 
28 namespace cxindex {
29 
30 class Logger;
31 typedef IntrusiveRefCntPtr<Logger> LogRef;
32 
33 /// \brief Collects logging output and writes it to stderr when it's destructed.
34 /// Common use case:
35 /// \code
36 ///   if (LogRef Log = Logger::make(__func__)) {
37 ///     *Log << "stuff";
38 ///   }
39 /// \endcode
40 class Logger : public RefCountedBase<Logger> {
41   std::string Name;
42   bool Trace;
43   SmallString<64> Msg;
44   llvm::raw_svector_ostream LogOS;
45 public:
46   static const char *getEnvVar() {
47     static const char *sCachedVar = ::getenv("LIBCLANG_LOGGING");
48     return sCachedVar;
49   }
50   static bool isLoggingEnabled() { return getEnvVar() != 0; }
51   static bool isStackTracingEnabled() {
52     if (const char *EnvOpt = Logger::getEnvVar())
53       return llvm::StringRef(EnvOpt) == "2";
54     return false;
55   }
56   static LogRef make(llvm::StringRef name,
57                      bool trace = isStackTracingEnabled()) {
58     if (isLoggingEnabled())
59       return new Logger(name, trace);
60     return 0;
61   }
62 
63   explicit Logger(llvm::StringRef name, bool trace)
64     : Name(name), Trace(trace), LogOS(Msg) { }
65   ~Logger();
66 
67   Logger &operator<<(CXTranslationUnit);
68   Logger &operator<<(const FileEntry *FE);
69   Logger &operator<<(CXCursor cursor);
70   Logger &operator<<(CXSourceLocation);
71   Logger &operator<<(CXSourceRange);
72   Logger &operator<<(CXString);
73   Logger &operator<<(llvm::StringRef Str) { LogOS << Str; return *this; }
74   Logger &operator<<(const char *Str) {
75     if (Str)
76       LogOS << Str;
77     return *this;
78   }
79   Logger &operator<<(unsigned long N) { LogOS << N; return *this; }
80   Logger &operator<<(long N) { LogOS << N ; return *this; }
81   Logger &operator<<(unsigned int N) { LogOS << N; return *this; }
82   Logger &operator<<(int N) { LogOS << N; return *this; }
83   Logger &operator<<(char C) { LogOS << C; return *this; }
84   Logger &operator<<(unsigned char C) { LogOS << C; return *this; }
85   Logger &operator<<(signed char C) { LogOS << C; return *this; }
86   Logger &operator<<(const llvm::format_object_base &Fmt);
87 };
88 
89 }
90 }
91 
92 /// \brief Macros to automate common uses of Logger. Like this:
93 /// \code
94 ///   LOG_FUNC_SECTION {
95 ///     *Log << "blah";
96 ///   }
97 /// \endcode
98 #define LOG_SECTION(NAME) if (LogRef Log = clang::cxindex::Logger::make(NAME))
99 #define LOG_FUNC_SECTION LOG_SECTION(LLVM_FUNCTION_NAME)
100 
101 #endif
102