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 31namespace llvm { 32class 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/// 39extern 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/// 45bool 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/// 51void 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/// 78extern 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"; 83raw_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