1 //===- llvm/Support/Debug.h - Easy way to add debug output ------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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.
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.
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.
26 //===----------------------------------------------------------------------===//
28 #ifndef LLVM_SUPPORT_DEBUG_H
29 #define LLVM_SUPPORT_DEBUG_H
31 #include "llvm/Support/raw_ostream.h"
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.
40 extern bool DebugFlag;
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.
46 bool isCurrentDebugType(const char *Type);
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.
52 void setCurrentDebugType(const char *Type);
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:
59 /// DEBUG_WITH_TYPE("bitset", dbgs() << "Bitset contains: " << Bitset << "\n");
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; } \
68 #define isCurrentDebugType(X) (false)
69 #define setCurrentDebugType(X)
70 #define DEBUG_WITH_TYPE(TYPE, X) do { } while (0)
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
79 extern bool EnableDebugBuffering;
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";
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:
91 // DEBUG(dbgs() << "Bitset contains: " << Bitset << "\n");
93 #define DEBUG(X) DEBUG_WITH_TYPE(DEBUG_TYPE, X)
95 } // End llvm namespace