def pragmaSpace(ppt, line, result):
"Reserves space in a data segment for a variable"
lbl = line.expect("LABEL").value
size = line.expect("NUM").value
line.expect("EOL")
result.append(IR.Node(ppt, "Label", lbl, IR.PCExpr()))
result.append(IR.Node(ppt, "SetPC",
IR.SequenceExpr([IR.PCExpr(), "+",
IR.ConstantExpr(size)])))
def visitZPRelative(self, node, env):
(opcode, tested, expr) = node.data
arg = expr.value(env)
arg = arg - (env.getPC() + 3)
if arg < -128 or arg > 127:
# Otherwise, we replace it with a 'macro' of sorts by hand:
# $branch LOC -> $reversed_branch ^+6; JMP LOC
# We don't use temp labels here because labels need to have
# been fixed in place by this point, and JMP is always 3
# bytes long.
expansion = [IR.Node(node.ppt, "ZPRelative",
ExtendBranches.reversed[opcode],
tested,
IR.SequenceExpr([IR.PCExpr(), "+",
IR.ConstantExpr(6)])),
IR.Node(node.ppt, "Absolute", 'jmp', expr, None)]
node.nodetype = 'SEQUENCE'
node.data = expansion
if Cmd.warn_on_branch_extend:
print>>sys.stderr, str(node.ppt) + ": WARNING: " + \
opcode + " out of range, " \
"replacing with " + \
ExtendBranches.reversed[opcode] + \
"/jmp combo"
self.changed = True
node.accept(self, env)
else:
PCTracker.visitZPRelative(self, node, env)
def visitRelative(self, node, env):
(opcode, expr) = node.data[:2]
arg = expr.value(env)
arg = arg - (env.getPC() + 2)
if arg < -128 or arg > 127:
if Cmd.enable_4502_exts:
node.nodetype = "RelativeLong"
if Cmd.warn_on_branch_extend:
print(str(node.ppt) + ": WARNING: " \
"branch out of range, replacing with 16-bit relative branch", file=sys.stderr)
else:
if opcode == 'bra':
# If BRA - BRanch Always - is out of range, it's a JMP.
node.data = ('jmp', expr, None)
node.nodetype = "Absolute"
if Cmd.warn_on_branch_extend:
print(str(node.ppt) + ": WARNING: " \
"bra out of range, replacing with jmp", file=sys.stderr)
else:
# Otherwise, we replace it with a 'macro' of sorts by hand:
# $branch LOC -> $reversed_branch ^+5; JMP LOC
# We don't use temp labels here because labels need to have
# been fixed in place by this point, and JMP is always 3
# bytes long.
expansion = [
IR.Node(
node.ppt, "Relative",
ExtendBranches.reversed[opcode],
IR.SequenceExpr(
[IR.PCExpr(), "+",
IR.ConstantExpr(5)]), None),
IR.Node(node.ppt, "Absolute", 'jmp', expr, None)
]
node.nodetype = 'SEQUENCE'
node.data = expansion
if Cmd.warn_on_branch_extend:
print(str(node.ppt) + ": WARNING: " + \
opcode + " out of range, " \
"replacing with " + \
ExtendBranches.reversed[opcode] + \
"/jmp combo", file=sys.stderr)
self.changed = True
node.accept(self, env)
else:
PCTracker.visitRelative(self, node, env)
def atom():
"Parses lowest-priority expression components."
global templabelcount
next = line.lookahead(0).type
if next == "NUM":
return IR.ConstantExpr(line.expect("NUM").value)
elif next in ["LABEL", "X", "Y", "Z", "SP", "OPCODE"]:
return IR.LabelExpr(line.expect("LABEL").value)
elif next == "^":
line.expect("^")
return IR.PCExpr()
elif next == "[":
line.expect("[")
result = parse_expr(line)
line.expect("]")
return result
elif next == "+":
offset = 0
while next == "+":
offset += 1
line.expect("+")
next = line.lookahead(0).type
return IR.LabelExpr("*" + str(templabelcount + offset))
elif next == "-":
offset = 1
while next == "-":
offset -= 1
line.expect("-")
next = line.lookahead(0).type
return IR.LabelExpr("*" + str(templabelcount + offset))
elif next == ">":
line.expect(">")
return IR.HighByteExpr(atom())
elif next == "<":
line.expect("<")
return IR.LowByteExpr(atom())
else:
Err.log('Expected: expression')
def aux():
"Accumulates all IR nodes defined by this line."
if line.lookahead(0).type == "EOL":
pass
elif line.lookahead(1).type == ":":
newlabel = line.expect("LABEL").value
line.expect(":")
result.append(IR.Node(ppt, "Label", newlabel, IR.PCExpr()))
aux()
elif line.lookahead(0).type == "*":
global templabelcount
templabelcount = templabelcount + 1
result.append(
IR.Node(ppt, "Label", "*" + str(templabelcount), IR.PCExpr()))
line.expect("*")
aux()
elif line.lookahead(0).type == "." or line.lookahead(0).type == "`":
which = line.expect(".", "`").type
if (which == "."):
pragma = line.expect("LABEL").value
else:
pragma = "invoke"
pragmaFunction = "pragma" + pragma.title()
for mod in pragma_modules:
if hasattr(mod, pragmaFunction):
getattr(mod, pragmaFunction)(ppt, line, result)
break
else:
Err.log("Unknown pragma " + pragma)
else: # Instruction
opcode = line.expect("OPCODE").value
arg2 = None
if line.lookahead(0).type == "#":
mode = "Immediate"
line.expect("#")
arg = parse_expr(line)
line.expect("EOL")
elif line.lookahead(0).type == "(":
line.expect("(")
arg = parse_expr(line)
if line.lookahead(0).type == ",":
line.expect(",")
if line.lookahead(0).type == "X":
mode = "PointerX"
line.expect("X")
line.expect(")")
line.expect("EOL")
else:
mode = "PointerSPY"
line.expect("SP")
line.expect(")")
line.expect(",")
line.expect("Y")
line.expect("EOL")
else:
line.expect(")")
tok = line.expect(",", "EOL").type
if tok == "EOL":
mode = "Pointer"
else:
if line.lookahead(0).type == "Y":
mode = "PointerY"
line.expect("Y")
line.expect("EOL")
else:
mode = "PointerZ"
line.expect("Z")
line.expect("EOL")
elif line.lookahead(0).type == "EOL":
mode = "Implied"
arg = None
else:
arg = parse_expr(line)
tok = line.expect("EOL", ",").type
if tok == ",":
# Parser has to special-case the BBXn instructions,
# Which uniquely take two addresses
if opcode[:3] in ["bbs", "bbr"]:
arg2 = parse_expr(line)
mode = "Memory2"
else:
tok = line.expect("X", "Y", "Z").type
if tok == "X":
mode = "MemoryX"
elif tok == "Y":
mode = "MemoryY"
else:
mode = "MemoryZ"
line.expect("EOL")
else:
mode = "Memory"
result.append(IR.Node(ppt, mode, opcode, arg, arg2))
def aux():
"Accumulates all IR nodes defined by this line."
if line.lookahead(0).type == "EOL":
pass
elif line.lookahead(1).type == ":":
newlabel = line.expect("LABEL").value
line.expect(":")
result.append(IR.Node(ppt, "Label", newlabel, IR.PCExpr()))
aux()
elif line.lookahead(0).type == "*":
global templabelcount
templabelcount = templabelcount + 1
result.append(
IR.Node(ppt, "Label", "*" + str(templabelcount), IR.PCExpr()))
line.expect("*")
aux()
elif line.lookahead(0).type == "." or line.lookahead(0).type == "`":
which = line.expect(".", "`").type
if (which == "."): pragma = line.expect("LABEL").value
else: pragma = "invoke"
pragmaFunction = "pragma" + pragma.title()
for mod in pragma_modules:
if hasattr(mod, pragmaFunction):
getattr(mod, pragmaFunction)(ppt, line, result)
break
else:
Err.log("Unknown pragma " + pragma)
else: # Instruction
opcode = line.expect("OPCODE").value
if line.lookahead(0).type == "#":
mode = "Immediate"
line.expect("#")
arg = parse_expr(line)
line.expect("EOL")
elif line.lookahead(0).type == "(":
line.expect("(")
arg = parse_expr(line)
if line.lookahead(0).type == ",":
mode = "IndirectX"
line.expect(",")
line.expect("X")
line.expect(")")
line.expect("EOL")
else:
line.expect(")")
tok = line.expect(",", "EOL").type
if tok == "EOL":
mode = "Indirect"
else:
mode = "IndirectY"
line.expect("Y")
line.expect("EOL")
elif line.lookahead(0).type == "EOL":
mode = "Implied"
arg = None
else:
arg = parse_expr(line)
tok = line.expect("EOL", ",").type
if tok == ",":
tok = line.expect("X", "Y").type
if tok == "X": mode = "MemoryX"
else: mode = "MemoryY"
line.expect("EOL")
else:
mode = "Memory"
result.append(IR.Node(ppt, mode, opcode, arg))