lib/Support/Debug.cpp

   1 //===-- Debug.cpp - An easy way to add debug output to your code ----------===//
   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 handle 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 use the SET_DEBUG_TYPE("foo") macro to specify
  17 // that your debug code belongs to class "foo".  Then, on the command line, you
  18 // can specify '-debug-only=foo' to enable JUST the debug information for the
  19 // foo class.
  20 //
  21 // When compiling in release mode, the -debug-* options and all code in DEBUG()
  22 // statements disappears, so it does not effect the runtime of the code.
  23 //
  24 //===----------------------------------------------------------------------===//
  25
  26 #include "llvm/Support/CommandLine.h"
  27 #include "llvm/Support/Debug.h"
  28 using namespace llvm;
  29
  30 // All Debug.h functionality is a no-op in NDEBUG mode.
  31 #ifndef NDEBUG
  32 bool llvm::DebugFlag;  // DebugFlag - Exported boolean set by the -debug option
  33
  34 // -debug - Command line option to enable the DEBUG statements in the passes.
  35 // This flag may only be enabled in debug builds.
  36 static cl::opt<bool, true>
  37 Debug("debug", cl::desc("Enable debug output"), cl::Hidden,
  38       cl::location(DebugFlag));
  39
  40 static std::string CurrentDebugType;
  41 static struct DebugOnlyOpt {
  42   void operator=(const std::string &Val) const {
  43     DebugFlag |= !Val.empty();
  44     CurrentDebugType = Val;
  45   }
  46 } DebugOnlyOptLoc;
  47
  48 static cl::opt<DebugOnlyOpt, true, cl::parser<std::string> >
  49 DebugOnly("debug-only", cl::desc("Enable a specific type of debug output"),
  50           cl::Hidden, cl::value_desc("debug string"),
  51           cl::location(DebugOnlyOptLoc), cl::ValueRequired);
  52
  53 // isCurrentDebugType - Return true if the specified string is the debug type
  54 // specified on the command line, or if none was specified on the command line
  55 // with the -debug-only=X option.
  56 //
  57 bool llvm::isCurrentDebugType(const char *DebugType) {
  58   return CurrentDebugType.empty() || DebugType == CurrentDebugType;
  59 }
  60 #else
  61 // Avoid "has no symbols" warning.
  62 int Debug_dummy = 0;
  63 #endif