Added transparent software breakpoint support for user debuggers:

* The bulk of the work -- i.e. juggling the software and hardware breakpoints,
  watchpoints, and memory reads/writes -- is done in the new class
  BreakpointManager.
* For the architectures a few capability macros have to be defined, one
  pointing to the software breakpoint instruction opcode. Done for x86.
* Some more simplifications in the user debugger code, made possible by the
  recently introduced debugger_changed_condition attribute.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31214 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/arch/user_debugger.h

@@ -50,6 +50,34 @@ status_t arch_clear_kernel_watchpoint(void *address);
 
 #include <arch_user_debugger.h>
 
+// Defaults for macros defined by the architecture specific header:
+
+// maximum number of instruction breakpoints
+#ifndef DEBUG_MAX_BREAKPOINTS
+#	define DEBUG_MAX_BREAKPOINTS 0
+#endif
+
+// maximum number of data watchpoints
+#ifndef DEBUG_MAX_WATCHPOINTS
+#	define DEBUG_MAX_WATCHPOINTS 0
+#endif
+
+// the software breakpoint instruction
+#if !defined(DEBUG_SOFTWARE_BREAKPOINT)	\
+	|| !defined(DEBUG_SOFTWARE_BREAKPOINT_SIZE)
+#	undef DEBUG_SOFTWARE_BREAKPOINT
+#	undef DEBUG_SOFTWARE_BREAKPOINT_SIZE
+#	define DEBUG_SOFTWARE_BREAKPOINT		NULL
+#	define DEBUG_SOFTWARE_BREAKPOINT_SIZE	0
+#endif
+
+// Boolean whether break- and watchpoints use the same registers. If != 0, then
+// DEBUG_MAX_BREAKPOINTS == DEBUG_MAX_WATCHPOINTS and either specifies the
+// total count of break- plus watchpoints.
+#ifndef DEBUG_SHARED_BREAK_AND_WATCHPOINTS
+#	define DEBUG_SHARED_BREAK_AND_WATCHPOINTS 0
+#endif
+
 #endif	// _ASSEMBLER
 
 #endif	// KERNEL_ARCH_USER_DEBUGGER_H