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 // DEBUG() requires the DEBUG_TYPE macro to be defined. Set it 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 namespace llvm { 32 33 class raw_ostream; 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 /// 40 extern 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 /// 46 bool 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 /// 52 void 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 (false) 66 67 #else 68 #define isCurrentDebugType(X) (false) 69 #define setCurrentDebugType(X) 70 #define DEBUG_WITH_TYPE(TYPE, X) do { } while (false) 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 /// 79 extern 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"; 84 raw_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 namespace llvm 96 97 #endif // LLVM_SUPPORT_DEBUG_H 98
