Move debugging support out of Statistic.h into Debug.h, implement the new DEBUG_TYPE facilities

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7490 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 53 insertions, 0 deletions

diff --git a/include/llvm/Support/Debug.h b/include/llvm/Support/Debug.h
new file mode 100644
index 0000000000..0a4c8a7784
--- /dev/null
+++ b/include/llvm/Support/Debug.h
@@ -0,0 +1,53 @@
+//===- Debug.h - An easy way to add debug output to your code ---*- C++ -*-===//
+//
+// This file implements a handle way of adding debugging information to your
+// code, without it being enabled all of the time, and without having to add
+// command line options to enable it.
+//
+// In particular, just wrap your code with the DEBUG() macro, and it will be
+// enabled automatically if you specify '-debug' on the command-line.
+// Alternatively, you can also use the SET_DEBUG_TYPE("foo") macro to specify
+// that your debug code belongs to class "foo".  Then, on the command line, you
+// can specify '-debug-only=foo' to enable JUST the debug information for the
+// foo class.
+//
+// When compiling in release mode, the -debug-* options and all code in DEBUG()
+// statements disappears, so it does not effect the runtime of the code.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_DEBUG_H
+#define SUPPORT_DEBUG_H
+
+// DebugFlag - This boolean is set to true if the '-debug' command line option
+// is specified.  This should probably not be referenced directly, instead, use
+// the DEBUG macro below.
+//
+extern bool DebugFlag;
+
+// isCurrentDebugType - Return true if the specified string is the debug type
+// specified on the command line, or if none was specified on the command line
+// with the -debug-only=X option.
+//
+bool isCurrentDebugType(const char *Type);
+
+// DEBUG macro - This macro should be used by passes to emit debug information.
+// In the '-debug' option is specified on the commandline, and if this is a
+// debug build, then the code specified as the option to the macro will be
+// executed.  Otherwise it will not be.  Example:
+//
+// DEBUG(cerr << "Bitset contains: " << Bitset << "\n");
+//
+
+#ifndef DEBUG_TYPE
+#define DEBUG_TYPE ""
+#endif
+
+#ifdef NDEBUG
+#define DEBUG(X)
+#else
+#define DEBUG(X) \
+  do { if (DebugFlag && isCurrentDebugType(DEBUG_TYPE)) { X; } } while (0)
+#endif
+
+#endif