Debug.h revision 2b7fef0ad4bfaaf9fd41cda5abda35aab701b598 
1//===- llvm/Support/Debug.h - Easy way to add debug output ------*- 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// This file implements a handy way of adding debugging information to your
11// code, without it being enabled all of the time, and without having to add
12// command line options to enable it.
13//
14// In particular, just wrap your code with the DEBUG() macro, and it will be
15// enabled automatically if you specify '-debug' on the command-line.
16// Alternatively, you can also use the SET_DEBUG_TYPE("foo") macro to specify
17// that your debug code belongs to class "foo".  Then, on the command line, you
18// can specify '-debug-only=foo' to enable JUST the debug information for the
19// foo class.
20//
21// When compiling without assertions, the -debug-* options and all code in
22// DEBUG() statements disappears, so it does not affect the runtime of the code.
23//
24//===----------------------------------------------------------------------===//
25
26#ifndef LLVM_SUPPORT_DEBUG_H
27#define LLVM_SUPPORT_DEBUG_H
28
29#include "llvm/Support/raw_ostream.h"
30
31namespace llvm {
32
33/// DEBUG_TYPE macro - Files can specify a DEBUG_TYPE as a string, which causes
34/// all of their DEBUG statements to be activatable with -debug-only=thatstring.
35#ifndef DEBUG_TYPE
36#define DEBUG_TYPE ""
37#endif
38
39#ifndef NDEBUG
40/// DebugFlag - This boolean is set to true if the '-debug' command line option
41/// is specified.  This should probably not be referenced directly, instead, use
42/// the DEBUG macro below.
43///
44extern bool DebugFlag;
45
46/// isCurrentDebugType - Return true if the specified string is the debug type
47/// specified on the command line, or if none was specified on the command line
48/// with the -debug-only=X option.
49///
50bool isCurrentDebugType(const char *Type);
51
52/// setCurrentDebugType - Set the current debug type, as if the -debug-only=X
53/// option were specified.  Note that DebugFlag also needs to be set to true for
54/// debug output to be produced.
55///
56void setCurrentDebugType(const char *Type);
57
58/// DEBUG_WITH_TYPE macro - This macro should be used by passes to emit debug
59/// information.  In the '-debug' option is specified on the commandline, and if
60/// this is a debug build, then the code specified as the option to the macro
61/// will be executed.  Otherwise it will not be.  Example:
62///
63/// DEBUG_WITH_TYPE("bitset", dbgs() << "Bitset contains: " << Bitset << "\n");
64///
65/// This will emit the debug information if -debug is present, and -debug-only
66/// is not specified, or is specified as "bitset".
67#define DEBUG_WITH_TYPE(TYPE, X)                                        \
68  do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType(TYPE)) { X; } \
69  } while (0)
70
71#else
72#define isCurrentDebugType(X) (false)
73#define setCurrentDebugType(X)
74#define DEBUG_WITH_TYPE(TYPE, X) do { } while (0)
75#endif
76
77/// EnableDebugBuffering - This defaults to false.  If true, the debug
78/// stream will install signal handlers to dump any buffered debug
79/// output.  It allows clients to selectively allow the debug stream
80/// to install signal handlers if they are certain there will be no
81/// conflict.
82///
83extern bool EnableDebugBuffering;
84
85/// dbgs() - This returns a reference to a raw_ostream for debugging
86/// messages.  If debugging is disabled it returns errs().  Use it
87/// like: dbgs() << "foo" << "bar";
88raw_ostream &dbgs();
89
90// DEBUG macro - This macro should be used by passes to emit debug information.
91// In the '-debug' option is specified on the commandline, and if this is a
92// debug build, then the code specified as the option to the macro will be
93// executed.  Otherwise it will not be.  Example:
94//
95// DEBUG(dbgs() << "Bitset contains: " << Bitset << "\n");
96//
97#define DEBUG(X) DEBUG_WITH_TYPE(DEBUG_TYPE, X)
98
99} // End llvm namespace
100
101#endif
102