cleanup, now only output.c accesses CPU_state.pc

git-svn-id: https://svn.code.sf.net/p/acme-crossass/code-0/trunk@186 4df02467-bbd4-4a76-a152-e7ce94205b78

src/acme.c

@@ -587,3 +587,41 @@ int main(int argc, const char *argv[])
 		save_output_file();
 	return ACME_finalize(EXIT_SUCCESS);	// dump labels, if wanted
 }
+
+/*
+TODO - maybe add a "use version" switch to ease assembling old sources?
+relevant changes are:
+
+"0.05"
+	...would be the syntax before any changes
+	(how was offset assembly ended? '*' in a line on its own?)
+	BIT without any arg would output $2c, masking the next two bytes
+"0.07"
+	"leading zeroes" info is now stored in symbols as well
+	changed argument order of mvp/mvn
+	!cbm outputs warning to use !ct pet instead
+	!end changed to !eof
+	*= is now segment change instead of offset assembly
+	added !pseudopc/!realpc
+"0.86"
+	!pseudopc/!realpc gives a warning to use !pseudopc{} instead
+"0.89"
+	>> now does ASR everywhere, added >>> as LSR
+	numbers before mnemonics are no longer interpreted as labels
+"0.93"
+	*= no longer ends offset assembly
+"0.94.6"
+	powerof is now right-associative
+"0.94.8"
+	disabled !cbm
+	disabled !pseudopc/!realpc
+	disabled !subzone
+"0.94.12"
+	new !for syntax
+"0.95.2"
+	changed ANC#8 from 0x2b to 0x0b
+"future"
+	backslash escaping (= strings)
+	TODO: paths should be relative to file, not start dir
+	TODO: ignore leading zeroes?
+*/

src/alu.c

@@ -2049,6 +2049,8 @@ intval_t ALU_any_int(void)	// ACCEPT_UNDEFINED
 // EMPTY: complain _seriously_
 // UNDEFINED: complain _seriously_
 // FLOAT: convert to int
+// FIXME - only very few callers actually _need_ a serious error to be thrown,
+// so throw a normal one here and pass ok/fail as return value, so caller can react.
 void ALU_defined_int(struct number *intresult)	// no ACCEPT constants?
 {
 	struct expression	expression;

src/cpu.c

@@ -122,4 +122,6 @@ void cputype_passinit(const struct cpu_type *cpu_type)
 {
 	// handle cpu type (default is 6502)
 	CPU_state.type = cpu_type ? cpu_type : &cpu_type_6502;
+	CPU_state.a_is_long = FALSE;	// short accu
+	CPU_state.xy_are_long = FALSE;	// short index regs
 }

src/mnemo.c

@@ -783,17 +783,18 @@ static void not_in_bank(intval_t target)
 // helper function for branches with 8-bit offset (including bbr0..7/bbs0..7)
 static void near_branch(int preoffset)
 {
+	struct number	pc;
 	struct number	target;
 	intval_t	offset	= 0;	// dummy value, to not throw more errors than necessary
 
+	vcpu_read_pc(&pc);
 	get_int_arg(&target, TRUE);
 	typesystem_want_addr(&target);
-	// FIXME - read pc via function call instead!
-	if (CPU_state.pc.flags & target.flags & NUMBER_IS_DEFINED) {
+	if (pc.flags & target.flags & NUMBER_IS_DEFINED) {
 		if ((target.val.intval | 0xffff) != 0xffff) {
 			not_in_bank(target.val.intval);
 		} else {
-			offset = (target.val.intval - (CPU_state.pc.val.intval + preoffset)) & 0xffff;	// clip to 16 bit offset
+			offset = (target.val.intval - (pc.val.intval + preoffset)) & 0xffff;	// clip to 16 bit offset
 			// fix sign
 			if (offset & 0x8000)
 				offset -= 0x10000;
@@ -817,17 +818,18 @@ static void near_branch(int preoffset)
 // helper function for relative addressing with 16-bit offset
 static void far_branch(int preoffset)
 {
+	struct number	pc;
 	struct number	target;
 	intval_t	offset	= 0;	// dummy value, to not throw more errors than necessary
 
+	vcpu_read_pc(&pc);
 	get_int_arg(&target, TRUE);
 	typesystem_want_addr(&target);
-	// FIXME - read pc via function call instead!
-	if (CPU_state.pc.flags & target.flags & NUMBER_IS_DEFINED) {
+	if (pc.flags & target.flags & NUMBER_IS_DEFINED) {
 		if ((target.val.intval | 0xffff) != 0xffff) {
 			not_in_bank(target.val.intval);
 		} else {
-			offset = (target.val.intval - (CPU_state.pc.val.intval + preoffset)) & 0xffff;
+			offset = (target.val.intval - (pc.val.intval + preoffset)) & 0xffff;
 			// no further checks necessary, 16-bit branches can access whole bank
 		}
 	}

src/output.c

@@ -496,8 +496,6 @@ void Output_passinit(void)
 	CPU_state.pc.flags = 0;	// not defined yet
 	CPU_state.pc.val.intval = 0;	// same as output's write_idx on pass init
 	CPU_state.add_to_pc = 0;	// increase PC by this at end of statement
-	CPU_state.a_is_long = FALSE;	// short accu
-	CPU_state.xy_are_long = FALSE;	// short index regs
 }
 
 
@@ -630,3 +628,19 @@ void vcpu_end_statement(void)
 	CPU_state.pc.val.intval = (CPU_state.pc.val.intval + CPU_state.add_to_pc) & 0xffff;
 	CPU_state.add_to_pc = 0;
 }
+
+// start offset assembly
+void pseudopc_start(struct pseudopc *buffer, struct number *new_pc)
+{
+	buffer->flags = CPU_state.pc.flags;
+	buffer->offset = (new_pc->val.intval - CPU_state.pc.val.intval) & 0xffff;
+	CPU_state.pc.val.intval = new_pc->val.intval;
+	CPU_state.pc.flags |= NUMBER_IS_DEFINED;	// FIXME - remove when allowing undefined!
+	//new: CPU_state.pc.flags = new_pc->flags & (NUMBER_IS_DEFINED | NUMBER_EVER_UNDEFINED);
+}
+// end offset assembly
+void pseudopc_end(struct pseudopc *buffer)
+{
+	CPU_state.pc.val.intval = (CPU_state.pc.val.intval - buffer->offset) & 0xffff;
+	CPU_state.pc.flags = buffer->flags;
+}

src/output.h

@@ -27,6 +27,11 @@ struct vcpu {
 	boolean			a_is_long;
 	boolean			xy_are_long;
 };
+// buffer to hold outer state while parsing "pseudopc" block
+struct pseudopc {
+	intval_t	offset;
+	int		flags;
+};
 
 
 // variables
@@ -98,6 +103,10 @@ extern void vcpu_read_pc(struct number *target);
 extern int vcpu_get_statement_size(void);
 // adjust program counter (called at end of each statement)
 extern void vcpu_end_statement(void);
+// start offset assembly
+extern void pseudopc_start(struct pseudopc *buffer, struct number *new_pc);
+// end offset assembly
+extern void pseudopc_end(struct pseudopc *buffer);
 
 
 #endif

src/pseudoopcodes.c

@@ -540,18 +540,10 @@ static enum eos po_skip(void)	// now GotByte = illegal char
 // insert byte until PC fits condition
 static enum eos po_align(void)
 {
-	// FIXME - read cpu state via function call!
 	struct number	andresult,
 			equalresult;
-	intval_t	fill,
-			test	= CPU_state.pc.val.intval;
-
-	// make sure PC is defined.
-	if ((CPU_state.pc.flags & NUMBER_IS_DEFINED) == 0) {
-		Throw_error(exception_pc_undefined);
-		CPU_state.pc.flags |= NUMBER_IS_DEFINED;	// do not complain again
-		return SKIP_REMAINDER;
-	}
+	intval_t	fill;
+	struct number	pc;
 
 	// TODO:
 	// now: !align ANDVALUE, EQUALVALUE [,FILLVALUE]
@@ -565,35 +557,37 @@ static enum eos po_align(void)
 		fill = ALU_any_int();
 	else
 		fill = CPU_state.type->default_align_value;
-	while ((test++ & andresult.val.intval) != equalresult.val.intval)
+
+	// make sure PC is defined
+	vcpu_read_pc(&pc);
+	if (!(pc.flags & NUMBER_IS_DEFINED)) {
+		Throw_error(exception_pc_undefined);
+		return SKIP_REMAINDER;
+	}
+
+	while ((pc.val.intval++ & andresult.val.intval) != equalresult.val.intval)
 		output_8(fill);
 	return ENSURE_EOS;
 }
 
-
 static const char	Error_old_offset_assembly[]	=
 	"\"!pseudopc/!realpc\" is obsolete; use \"!pseudopc {}\" instead.";
 // start offset assembly
-// FIXME - split in two parts and move backend to output.c?
 // TODO - maybe add a label argument to assign the block size afterwards (for assemble-to-end-address) (or add another pseudo opcode)
 static enum eos po_pseudopc(void)
 {
-	// FIXME - read pc using a function call!
-	struct number	new_pc_result;
-	intval_t	new_offset;
-	int		outer_flags	= CPU_state.pc.flags;
+	struct pseudopc	buffer;
+	struct number	new_pc;
 
-	// set new
-	ALU_defined_int(&new_pc_result);	// FIXME - allow for undefined! (complaining about non-addresses would be logical, but annoying)
-	new_offset = (new_pc_result.val.intval - CPU_state.pc.val.intval) & 0xffff;
-	CPU_state.pc.val.intval = new_pc_result.val.intval;
-	CPU_state.pc.flags |= NUMBER_IS_DEFINED;	// FIXME - remove when allowing undefined!
+	// get new value
+	ALU_defined_int(&new_pc);	// FIXME - allow for undefined! (complaining about non-addresses would be logical, but annoying)
 	// TODO - accept ', name = "section name"'
+	// remember old state in buffer, set new state
+	pseudopc_start(&buffer, &new_pc);
 	// if there's a block, parse that and then restore old value!
 	if (Parse_optional_block()) {
-		// restore old
-		CPU_state.pc.val.intval = (CPU_state.pc.val.intval - new_offset) & 0xffff;
-		CPU_state.pc.flags = outer_flags;
+		// restore old state
+		pseudopc_end(&buffer);
 	} else {
 		// not using a block is no longer allowed
 		Throw_error(Error_old_offset_assembly);