Add watchpoint capabilities hook to Architecture.

Will be used by the watchpoint manager and/or watchpoint UI to
present and/or handle the relative limitations of the current platform.

src/apps/debugger/arch/Architecture.h

@@ -1,6 +1,6 @@
 /*
  * Copyright 2009, Ingo Weinhold, [email protected].
- * Copyright 2011, Rene Gollent, [email protected].
+ * Copyright 2011-2012, Rene Gollent, [email protected].
  * Distributed under the terms of the MIT License.
  */
 #ifndef ARCHITECTURE_H
@@ -38,6 +38,12 @@ enum {
 };
 
 
+enum {
+	WATCHPOINT_CAPABILITY_FLAG_READ = 1,
+	WATCHPOINT_CAPABILITY_FLAG_WRITE = 2
+};
+
+
 class Architecture : public BReferenceable {
 public:
 								Architecture(TeamMemory* teamMemory,
@@ -105,6 +111,11 @@ public:
 									bool useExistingTrace = false);
 										// team is not locked
 
+	virtual	status_t			GetWatchpointDebugCapabilities(
+									int32& _maxRegisterCount,
+									uint8& _watchpointCapabilityFlags) = 0;
+
+
 protected:
 			TeamMemory*			fTeamMemory;
 			uint8				fAddressSize;

src/apps/debugger/arch/x86/ArchitectureX86.cpp

@@ -1,6 +1,6 @@
 /*
  * Copyright 2009-2012, Ingo Weinhold, [email protected].
- * Copyright 2011, Rene Gollent, [email protected].
+ * Copyright 2011-2012, Rene Gollent, [email protected].
  * Distributed under the terms of the MIT License.
  */
 
@@ -611,6 +611,22 @@ ArchitectureX86::GetInstructionInfo(target_addr_t address,
 }
 
 
+status_t
+ArchitectureX86::GetWatchpointDebugCapabilities(int32& _maxRegisterCount,
+	uint8& _watchpointCapabilityFlags)
+{
+	// while x86 technically has 4 hardware debug registers, one is reserved by
+	// the kernel, and one is required for breakpoint support, which leaves
+	// two available for watchpoints.
+	_maxRegisterCount = 2;
+
+	// x86 only supports write watchpoints.
+	_watchpointCapabilityFlags = WATCHPOINT_CAPABILITY_FLAG_WRITE;
+
+	return B_OK;
+}
+
+
 void
 ArchitectureX86::_AddRegister(int32 index, const char* name,
 	uint32 bitSize, uint32 valueType, register_type type, bool calleePreserved)

src/apps/debugger/arch/x86/ArchitectureX86.h

@@ -1,6 +1,6 @@
 /*
  * Copyright 2009, Ingo Weinhold, [email protected].
- * Copyright 2011, Rene Gollent, [email protected].
+ * Copyright 2011-2012, Rene Gollent, [email protected].
  * Distributed under the terms of the MIT License.
  */
 #ifndef ARCHITECTURE_X86_H
@@ -23,7 +23,7 @@ public:
 
 	virtual	status_t			Init();
 
-	virtual int32				StackGrowthDirection() const;	
+	virtual int32				StackGrowthDirection() const;
 
 	virtual	int32				CountRegisters() const;
 	virtual	const Register*		Registers() const;
@@ -61,6 +61,10 @@ public:
 	virtual	status_t			GetInstructionInfo(target_addr_t address,
 									InstructionInfo& _info);
 
+	virtual	status_t			GetWatchpointDebugCapabilities(
+									int32& _maxRegisterCount,
+									uint8& _watchpointCapabilityFlags);
+
 private:
 			struct ToDwarfRegisterMap;
 			struct FromDwarfRegisterMap;