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 class raw_ostream; 33 34 #ifndef NDEBUG 35 /// DebugFlag - This boolean is set to true if the '-debug' command line option 36 /// is specified. This should probably not be referenced directly, instead, use 37 /// the DEBUG macro below. 38 /// 39 extern bool DebugFlag; 40 41 /// isCurrentDebugType - Return true if the specified string is the debug type 42 /// specified on the command line, or if none was specified on the command line 43 /// with the -debug-only=X option. 44 /// 45 bool isCurrentDebugType(const char *Type); 46 47 /// setCurrentDebugType - Set the current debug type, as if the -debug-only=X 48 /// option were specified. Note that DebugFlag also needs to be set to true for 49 /// debug output to be produced. 50 /// 51 void setCurrentDebugType(const char *Type); 52 53 /// DEBUG_WITH_TYPE macro - This macro should be used by passes to emit debug 54 /// information. In the '-debug' option is specified on the commandline, and if 55 /// this is a debug build, then the code specified as the option to the macro 56 /// will be executed. Otherwise it will not be. Example: 57 /// 58 /// DEBUG_WITH_TYPE("bitset", dbgs() << "Bitset contains: " << Bitset << "\n"); 59 /// 60 /// This will emit the debug information if -debug is present, and -debug-only 61 /// is not specified, or is specified as "bitset". 62 #define DEBUG_WITH_TYPE(TYPE, X) \ 63 do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType(TYPE)) { X; } \ 64 } while (0) 65 66 #else 67 #define isCurrentDebugType(X) (false) 68 #define setCurrentDebugType(X) 69 #define DEBUG_WITH_TYPE(TYPE, X) do { } while (0) 70 #endif 71 72 /// EnableDebugBuffering - This defaults to false. If true, the debug 73 /// stream will install signal handlers to dump any buffered debug 74 /// output. It allows clients to selectively allow the debug stream 75 /// to install signal handlers if they are certain there will be no 76 /// conflict. 77 /// 78 extern bool EnableDebugBuffering; 79 80 /// dbgs() - This returns a reference to a raw_ostream for debugging 81 /// messages. If debugging is disabled it returns errs(). Use it 82 /// like: dbgs() << "foo" << "bar"; 83 raw_ostream &dbgs(); 84 85 // DEBUG macro - This macro should be used by passes to emit debug information. 86 // In the '-debug' option is specified on the commandline, and if this is a 87 // debug build, then the code specified as the option to the macro will be 88 // executed. Otherwise it will not be. Example: 89 // 90 // DEBUG(dbgs() << "Bitset contains: " << Bitset << "\n"); 91 // 92 #define DEBUG(X) DEBUG_WITH_TYPE(DEBUG_TYPE, X) 93 94 } // End llvm namespace 95 96 #endif 97