SCI: Replace magic numbers in reg_t handling with symbols

5 files changed, 18 insertions, 12 deletions

diff --git a/engines/sci/engine/kernel.cpp b/engines/sci/engine/kernel.cpp
index 60d4ccbf22..13a836ab77 100644
--- a/engines/sci/engine/kernel.cpp
+++ b/engines/sci/engine/kernel.cpp
@@ -380,7 +380,7 @@ uint16 Kernel::findRegType(reg_t reg) {
 	if (!reg.getSegment())
 		return SIG_TYPE_INTEGER | (reg.getOffset() ? 0 : SIG_TYPE_NULL);
 
-	if (reg.getSegment() == 0xFFFF)
+	if (reg.getSegment() == kUninitializedSegment)
 		return SIG_TYPE_UNINITIALIZED;
 
 	// Otherwise it's an object
diff --git a/engines/sci/engine/scriptdebug.cpp b/engines/sci/engine/scriptdebug.cpp
index d15cf83b71..971c721d6b 100644
--- a/engines/sci/engine/scriptdebug.cpp
+++ b/engines/sci/engine/scriptdebug.cpp
@@ -230,12 +230,12 @@ reg_t disassemble(EngineState *s, reg32_t pos, reg_t objAddr, bool printBWTag, b
 			if (opsize) {
 				int8 offset = (int8)scr[retval.getOffset()];
 				retval.incOffset(1);
-				debugN("\t%02x  [%04x]", 0xff & offset, 0xffff & (retval.getOffset() + offset));
+				debugN("\t%02x  [%04x]", 0xff & offset, kOffsetMask & (retval.getOffset() + offset));
 			}
 			else {
 				int16 offset = (int16)READ_SCI11ENDIAN_UINT16(&scr[retval.getOffset()]);
 				retval.incOffset(2);
-				debugN("\t%04x  [%04x]", 0xffff & offset, 0xffff & (retval.getOffset() + offset));
+				debugN("\t%04x  [%04x]", 0xffff & offset, kOffsetMask & (retval.getOffset() + offset));
 			}
 			break;
 
diff --git a/engines/sci/engine/vm.cpp b/engines/sci/engine/vm.cpp
index 74a2841521..a9d575b013 100644
--- a/engines/sci/engine/vm.cpp
+++ b/engines/sci/engine/vm.cpp
@@ -120,7 +120,7 @@ extern const char *opcodeNames[]; // from scriptdebug.cpp
 
 static reg_t read_var(EngineState *s, int type, int index) {
 	if (validate_variable(s->variables[type], s->stack_base, type, s->variablesMax[type], index)) {
-		if (s->variables[type][index].getSegment() == 0xffff) {
+		if (s->variables[type][index].getSegment() == kUninitializedSegment) {
 			switch (type) {
 			case VAR_TEMP: {
 				// Uninitialized read on a temp
@@ -194,7 +194,7 @@ static void write_var(EngineState *s, int type, int index, reg_t value) {
 		//  this happens at least in sq1/room 44 (slot-machine), because a send is missing parameters, then
 		//  those parameters are taken from uninitialized stack and afterwards they are copied back into temps
 		//  if we don't remove the segment, we would get false-positive uninitialized reads later
-		if (type == VAR_TEMP && value.getSegment() == 0xffff)
+		if (type == VAR_TEMP && value.getSegment() == kUninitializedSegment)
 			value.setSegment(0);
 
 		s->variables[type][index] = value;
@@ -331,7 +331,7 @@ ExecStack *send_selector(EngineState *s, reg_t send_obj, reg_t work_obj, StackPt
 
 		assert(argp[0].toUint16() == argc); // The first argument is argc
 		ExecStack xstack(work_obj, send_obj, curSP, argc, argp,
-							0xFFFF, curFP, selector, -1, -1, -1, -1,
+							kUninitializedSegment, curFP, selector, -1, -1, -1, -1,
 							origin, stackType);
 
 		if (selectorType == kSelectorVariable)
@@ -360,7 +360,7 @@ static void addKernelCallToExecStack(EngineState *s, int kernelCallNr, int kerne
 	// Add stack frame to indicate we're executing a callk.
 	// This is useful in debugger backtraces if this
 	// kernel function calls a script itself.
-	ExecStack xstack(NULL_REG, NULL_REG, NULL, argc, argv - 1, 0xFFFF, make_reg32(0, 0),
+	ExecStack xstack(NULL_REG, NULL_REG, NULL, argc, argv - 1, kUninitializedSegment, make_reg32(0, 0),
 						-1, kernelCallNr, kernelSubCallNr, -1, -1, s->_executionStack.size() - 1, EXEC_STACK_TYPE_KERNEL);
 	s->_executionStack.push_back(xstack);
 }
@@ -884,7 +884,7 @@ void run_vm(EngineState *s) {
 			// We shouldn't initialize temp variables at all
 			//  We put special segment 0xFFFF in there, so that uninitialized reads can get detected
 			for (int i = 0; i < opparams[0]; i++)
-				s->xs->sp[i] = make_reg(0xffff, 0);
+				s->xs->sp[i] = make_reg(kUninitializedSegment, 0);
 
 			s->xs->sp += opparams[0];
 			break;
diff --git a/engines/sci/engine/vm.h b/engines/sci/engine/vm.h
index 18549e3a0e..dbd4ee13d6 100644
--- a/engines/sci/engine/vm.h
+++ b/engines/sci/engine/vm.h
@@ -116,7 +116,7 @@ struct ExecStack {
 		fp = sp = sp_;
 		argc = argc_;
 		variables_argp = argp_;
-		if (localsSegment_ != 0xFFFF)
+		if (localsSegment_ != kUninitializedSegment)
 			local_segment = localsSegment_;
 		else
 			local_segment = pc_.getSegment();
diff --git a/engines/sci/engine/vm_types.h b/engines/sci/engine/vm_types.h
index e60f52e85c..734f4d3101 100644
--- a/engines/sci/engine/vm_types.h
+++ b/engines/sci/engine/vm_types.h
@@ -30,6 +30,12 @@ namespace Sci {
 // Segment ID type
 typedef uint16 SegmentId;
 
+enum {
+	kUninitializedSegment = 0x1FFF,
+	kSegmentMask = 0x1FFF,
+	kOffsetMask = 0x7FFFF
+};
+
 struct reg_t {
 	// Segment and offset. These should never be accessed directly
 	SegmentId _segment;
@@ -61,14 +67,14 @@ struct reg_t {
 	}
 
 	bool isPointer() const {
-		return getSegment() != 0 && getSegment() != 0xFFFF;
+		return getSegment() != 0 && getSegment() != kUninitializedSegment;
 	}
 
 	uint16 requireUint16() const;
 	int16 requireSint16() const;
 
 	inline bool isInitialized() const {
-		return getSegment() != 0xFFFF;
+		return getSegment() != kUninitializedSegment;
 	}
 
 	// Comparison operators
@@ -173,7 +179,7 @@ static inline reg_t make_reg(SegmentId segment, uint16 offset) {
 	return r;
 }
 
-#define PRINT_REG(r) (0xffff) & (unsigned) (r).getSegment(), (unsigned) (r).getOffset()
+#define PRINT_REG(r) (kSegmentMask) & (unsigned) (r).getSegment(), (unsigned) (r).getOffset()
 
 // A true 32-bit reg_t
 struct reg32_t {