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