CPU-Z80-Disassembler

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lib/CPU/Z80/Disassembler.pm  view on Meta::CPAN

=cut

#------------------------------------------------------------------------------
# Hold a disassembly session
use base 'Class::Accessor';
__PACKAGE__->mk_accessors(
		'memory',		# memory to disassemble
		'_type',		# identified type of each memory address, TYPE_xxx
		'instr',		# array of Instruction objects at each address
		'labels',		# all defined labels
		'_call_instr',	# hash of all call instructions where we are blocked
		'_can_call',	# hash of all subroutines we may call:
						# 1 	 : can be called, no stack impact
						# 0      : has stack impact, needs to be checked manually
						# sub {} : call sub->($self, $next_addr) to handle 
						#		   stack impact and return next code addresses
						#          to continue disassembly after call
		'_block_comments',	
						# array of block comment string at each address, printed before
						# the address
		'header', 'footer',

lib/CPU/Z80/Disassembler.pm  view on Meta::CPAN

				}
				elsif ($can_call) {
					push @stack, $instr->next_addr;		# can continue
				}
			}
			
			# continue on next addresses
			push @stack, $instr->next_code;
		}
	
		# check if we can unwind any blocked calls, after all paths without calls are
		# exhausted
		push @stack, $self->_check_call_instr;
	}
}

#------------------------------------------------------------------------------
sub _check_call_instr {
	my($self) = @_;

	my @stack;
	
	# check simple call instructions where we blocked
	for my $addr (keys %{$self->_call_instr}) {
		my $instr = $self->_get_instr($addr);
		my $call_addr = $instr->NN;
		
		if (	# if any of the calls is conditional, then _can_call
				$instr->opcode =~ /call \w+,NN/
			||	
				# if address after the call is CODE, then _can_call
				$self->get_type($instr->next_addr) eq TYPE_CODE
			) {

t/data/zx48.asm  view on Meta::CPAN

; in the BC register or zero if no digits exist before commands.
; It is called from LINE-SCAN to check the syntax of the digits.
; It is called from MAIN-3 to extract the line number in preparation for
; inclusion of the line in the BASIC program area.
;
; Interestingly the calculator stack is moved from its normal place at the
; end of dynamic memory to an adequate area within the system variables area.
; This ensures that in a low memory situation, that valid line numbers can
; be extracted without raising an error and that memory can be reclaimed
; by deleting lines. If the stack was in its normal place then a situation
; arises whereby the Spectrum becomes locked with no means of reclaiming space.

;; E-LINE-NO
L19FB:  LD      HL,($5C59)      ; load HL from system variable E_LINE.

        DEC     HL              ; decrease so that NEXT_CHAR can be used
                                ; without skipping the first digit.

        LD      ($5C5D),HL      ; store in the system variable CH_ADD.

        RST     20H             ; NEXT-CHAR skips any noise and white-space

t/data/zx48_base.asm  view on Meta::CPAN

; in the BC register or zero if no digits exist before commands.
; It is called from LINE-SCAN to check the syntax of the digits.
; It is called from MAIN-3 to extract the line number in preparation for
; inclusion of the line in the BASIC program area.
;
; Interestingly the calculator stack is moved from its normal place at the
; end of dynamic memory to an adequate area within the system variables area.
; This ensures that in a low memory situation, that valid line numbers can
; be extracted without raising an error and that memory can be reclaimed
; by deleting lines. If the stack was in its normal place then a situation
; arises whereby the Spectrum becomes locked with no means of reclaiming space.

;; E-LINE-NO
E_LINE_NO:
        ld hl,(0x5C59)          ; load HL from system variable E_LINE.

        dec hl                  ; decrease so that NEXT_CHAR can be used
                                ; without skipping the first digit.

        ld (0x5C5D),hl          ; store in the system variable CH_ADD.

t/data/zx48_benchmark.asm  view on Meta::CPAN

; in the BC register or zero if no digits exist before commands.
; It is called from LINE-SCAN to check the syntax of the digits.
; It is called from MAIN-3 to extract the line number in preparation for
; inclusion of the line in the BASIC program area.
;
; Interestingly the calculator stack is moved from its normal place at the
; end of dynamic memory to an adequate area within the system variables area.
; This ensures that in a low memory situation, that valid line numbers can
; be extracted without raising an error and that memory can be reclaimed
; by deleting lines. If the stack was in its normal place then a situation
; arises whereby the Spectrum becomes locked with no means of reclaiming space.

;; E-LINE-NO

E_LINE_NO:
        ld hl, (E_LINE)         ; load HL from system variable E_LINE.

        dec hl                  ; decrease so that NEXT_CHAR can be used
                                ; without skipping the first digit.

        ld (CH_ADD), hl         ; store in the system variable CH_ADD.