1//===- CLog.h - Logging Interface -------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLVM_CLANG_TOOLS_LIBCLANG_CLOG_H
10#define LLVM_CLANG_TOOLS_LIBCLANG_CLOG_H
11
12#include "clang-c/Index.h"
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  class FileEntry;
27
28namespace cxindex {
29
30class Logger;
31typedef IntrusiveRefCntPtr<Logger> LogRef;
32
33/// 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
40class Logger : public RefCountedBase<Logger> {
41  std::string Name;
42  bool Trace;
43  SmallString<64> Msg;
44  llvm::raw_svector_ostream LogOS;
45public:
46  static const char *getEnvVar() {
47    static const char *sCachedVar = ::getenv("LIBCLANG_LOGGING");
48    return sCachedVar;
49  }
50  static bool isLoggingEnabled() { return getEnvVar() != nullptr; }
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 nullptr;
61  }
62
63  explicit Logger(llvm::StringRef name, bool trace)
64      : Name(std::string(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/// 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) \
99    if (clang::cxindex::LogRef Log = clang::cxindex::Logger::make(NAME))
100#define LOG_FUNC_SECTION LOG_SECTION(__func__)
101
102#endif
103