def program():
"""
Parses
program = "program" ident ";" declarations compoundStatement.
Generates code if no error is reported
"""
newObj('boolean', Type(Bool))
Bool.size = 8 # 64 bit sizes
newObj('integer', Type(Int))
Int.size = 8
newObj('true', Const(Bool, 1))
newObj('false', Const(Bool, 0))
newObj('read', StdProc([Ref(Int)]))
newObj('write', StdProc([Var(Int)]))
newObj('writeln', StdProc([]))
progStart()
if SC.sym == PROGRAM: getSym()
else: mark("'program' expected", 64)
ident = SC.val
if SC.sym == IDENT: getSym()
else: mark('program name expected', 65)
if SC.sym == SEMICOLON: getSym()
else: mark('; expected', 66)
declarations(genGlobalVars)
progEntry(ident)
x = compoundStatement()
return progExit(x)
def program():
newDecl('boolean', Type(CG.genBool(Bool)))
newDecl('integer', Type(CG.genInt(Int)))
newDecl('true', Const(Bool, 1))
newDecl('false', Const(Bool, 0))
newDecl('read', StdProc([Ref(Int)]))
newDecl('write', StdProc([Var(Int)]))
newDecl('writeln', StdProc([]))
CG.genProgStart()
if SC.sym == PROGRAM:
getSym()
else:
mark("'program' expected")
ident = SC.val
if SC.sym == IDENT:
getSym()
else:
mark('program name expected')
if SC.sym == SEMICOLON:
getSym()
else:
mark('; expected')
declarations(CG.genGlobalVars)
CG.genProgEntry(ident)
x = compoundStatement()
return CG.genProgExit(x)
def typ():
"""
Parses
type = ident |
"array" "[" expression ".." expression "]" "of" type |
"record" typedIds {";" typedIds} "end".
Returns a type descriptor
"""
if SC.sym not in FIRSTTYPE:
getSym()
mark("type expected", 37)
while SC.sym not in FIRSTTYPE | FOLLOWTYPE | STRONGSYMS:
getSym()
if SC.sym == IDENT:
ident = SC.val
x = find(ident)
getSym()
if type(x) == Type: x = Type(x.tp)
else: mark('not a type', 38)
elif SC.sym == ARRAY:
getSym()
if SC.sym == LBRAK: getSym()
else: mark("'[' expected", 39)
x = expression()
if type(x) != Const or x.val < 0: mark('bad lower bound', 40)
if SC.sym == PERIOD: getSym()
else: mark("'.' expected", 41)
if SC.sym == PERIOD: getSym()
else: mark("'.' expected", 42)
y = expression()
if type(y) != Const or y.val < x.val: mark('bad upper bound', 43)
if SC.sym == RBRAK: getSym()
else: mark("']' expected", 44)
if SC.sym == OF: getSym()
else: mark("'of' expected", 45)
z = typ().tp
l = y.val - x.val + 1
x = Type(genArray(Array(z, x.val, l)))
elif SC.sym == RECORD:
getSym()
openScope()
typedIds(Var)
while SC.sym == SEMICOLON:
getSym()
typedIds(Var)
if SC.sym == END: getSym()
else: mark("'end' expected", 46)
r = topScope()
closeScope()
x = Type(genRec(Record(r)))
else:
mark("type expected", 47)
x = Type(None)
return x
def program():
"""
Parses
program = "program" «write('program ')» ident «write(ident)»
";" «write(';')» declarations compoundStatement(1).
Generates code if no error is reported
"""
newObj('boolean', Type(Bool))
Bool.size = 4
newObj('integer', Type(Int))
Int.size = 4
newObj('true', Const(Bool, 1))
newObj('false', Const(Bool, 0))
newObj('read', StdProc([Ref(Int)]))
newObj('write', StdProc([Var(Int)]))
newObj('writeln', StdProc([]))
CG.progStart()
if SC.sym == PROGRAM:
#
write('program ')
writeHtml('program ')
#
getSym()
else:
mark("'program' expected")
ident = SC.val
if SC.sym == IDENT:
#
write(ident)
writeHtml(ident, _class='ident')
#
getSym()
else:
mark('program name expected')
if SC.sym == SEMICOLON:
getSym()
#
write(';')
writeln()
writeHtml(';')
writeHtmlLn()
#
else:
mark('; expected')
declarations(CG.genGlobalVars)
CG.progEntry(ident)
x = compoundStatement(1)
return CG.progExit(x)
def program():
newDecl('boolean', Type(CG.genBool(Bool)))
newDecl('integer', Type(CG.genInt(Int)))
newDecl('true', Const(Bool, 1))
newDecl('false', Const(Bool, 0))
newDecl('read', StdProc([], [Var(Int)]))
newDecl('write', StdProc([Var(Int)], []))
newDecl('writeln', StdProc([], []))
CG.genProgStart()
declarations(CG.genGlobalVars)
if SC.sym == PROGRAM: getSym()
else: mark("'program' expected")
ident = SC.val
if SC.sym == IDENT: getSym()
else: mark('program name expected')
openScope(); CG.genProgEntry(ident); x = body(ident, 0)
closeScope(); x = CG.genProgExit(x)
return x
def typ():
if SC.sym == IDENT:
ident = SC.val; x = find(ident)
if type(x) == Type: x = Type(x.val); getSym()
else: mark('type identifier expected')
elif SC.sym == LBRAK:
getSym(); x = expression()
if SC.sym == DOTDOT: getSym()
else: mark("'..' expected")
y = expression()
if SC.sym == RBRAK: getSym()
else: mark("']' expected")
if SC.sym == RARROW: getSym()
else: mark("'→' expected")
z = typ().val;
if type(x) != Const or x.val < 0: mark('bad lower bound')
elif type(y) != Const or y.val < x.val: mark('bad upper bound')
else: x = Type(CG.genArray(Array(z, x.val, y.val - x.val + 1)))
elif SC.sym == LPAREN:
getSym(); openScope(); typedIds()
if SC.sym == RPAREN: getSym()
else: mark("')' expected")
r = topScope(); closeScope()
x = Type(CG.genRec(Record(r)))
elif SC.sym == FULLPAREN:
pass
elif SC.sym == SET:
getSym();
if SC.sym == LBRAK: getSym()
else: mark ("'[' expected")
x = expression()
if SC.sym == DOTDOT: getSym()
else: mark("'..' expected")
y = expression()
if SC.sym == RBRAK: getSym()
else: mark("']' expected")
if type(x) != Const: mark('bad lower bound')
elif type(y) != Const or y.val < x.val: mark('bad upper bound')
else: x = Type(CG.genSet(Set(x.val, y.val - x.val + 1)))
else: mark('type expected')
return x
def typ():
if SC.sym not in FIRSTTYPE:
getSym()
mark("type expected")
while SC.sym not in FIRSTTYPE | STRONGSYMS | FOLLOWTYPE:
getSym()
if SC.sym == IDENT:
ident = SC.val
x = find(ident)
getSym()
if type(x) == Type: x = Type(x.val)
else:
mark('not a type')
x = Type(None)
elif SC.sym == ARRAY:
getSym()
if SC.sym == LBRAK: getSym()
else: mark("'[' expected")
x = expression()
if SC.sym == PERIOD: getSym()
else: mark("'.' expected")
if SC.sym == PERIOD: getSym()
else: mark("'.' expected")
y = expression()
if SC.sym == RBRAK: getSym()
else: mark("']' expected")
if SC.sym == OF: getSym()
else: mark("'of' expected")
z = typ().val
if type(x) != Const or x.val < 0:
mark('bad lower bound')
x = Type(None)
elif type(y) != Const or y.val < x.val:
mark('bad upper bound')
x = Type(None)
else:
x = Type(CG.genArray(Array(z, x.val, y.val - x.val + 1)))
elif SC.sym == RECORD:
getSym()
openScope()
typedIds(Var)
while SC.sym == SEMICOLON:
getSym()
typedIds(Var)
if SC.sym == END: getSym()
else: mark("'end' expected")
r = topScope()
closeScope()
x = Type(CG.genRec(Record(r)))
else:
x = Type(None)
return x
def typ():
"""
Parses
type = ident |
"array" "[" expression ".." expression "]" "of" type |
"record" typedIds {";" typedIds} "end".
Returns a type descriptor
"""
global depth
if SC.sym not in FIRSTTYPE:
getSym()
mark("type expected")
while SC.sym not in FIRSTTYPE | STRONGSYMS | FOLLOWTYPE:
getSym()
if SC.sym == IDENT:
# attribute
ident = SC.val
write(ident)
writeHtml(ident, _class='ident')
#
x = find(ident)
getSym()
if type(x) == Type: x = Type(x.tp)
else:
mark('not a type')
x = Type(None)
elif SC.sym == ARRAY:
depth += 1
# attribute
writeln()
write(indent * depth)
write('array ')
writeHtmlLn()
writeHtml(htmlIndent * depth)
writeHtml('array ')
#
getSym()
if SC.sym == LBRAK:
# attribute
write('[')
writeHtml('[')
#
getSym()
else:
mark("'[' expected")
x = expression()
if SC.sym == PERIOD:
# attribute
write(' .')
writeHtml(' .')
#
getSym()
else:
mark("'.' expected")
if SC.sym == PERIOD:
# attribute
write('. ')
writeHtml('. ')
#
getSym()
else:
mark("'.' expected")
y = expression()
if SC.sym == RBRAK:
# attribute
write('] ')
writeHtml('] ')
#
getSym()
else:
mark("']' expected")
if SC.sym == OF:
# attribute
write('of')
writeHtml('of')
#
getSym()
else:
mark("'of' expected")
z = typ().tp
if type(x) != Const or x.val < 0:
mark('bad lower bound')
x = Type(None)
elif type(y) != Const or y.val < x.val:
mark('bad upper bound')
y = Type(None)
else:
x = Type(CG.genArray(Array(z, x.val, y.val - x.val + 1)))
depth -= 1
elif SC.sym == RECORD:
# attributes
depth += 1
writeln()
write(indent * depth)
write('record')
writeln()
writeHtmlLn()
writeHtml(htmlIndent * depth)
writeHtml('record')
writeHtmlLn()
depth += 1
#
getSym()
# attributes
write(indent * depth)
write(SC.val)
writeHtml(htmlIndent * depth)
writeHtml(SC.val)
#
openScope()
typedIds(Var)
while SC.sym == SEMICOLON:
# attributes
write(';')
writeln()
writeHtml(';')
writeHtmlLn()
#
getSym()
# attributes
write(indent * depth)
write(SC.val)
writeHtml(htmlIndent * depth)
writeHtml(SC.val)
#
typedIds(Var)
# attributes
writeln()
writeHtmlLn()
depth -= 1
write(indent * depth)
writeHtml(htmlIndent * depth)
#
if SC.sym == END:
# attributes
write('end')
writeHtml('end')
#
getSym()
else:
mark("'end' expected")
r = topScope()
closeScope()
x = Type(CG.genRec(Record(r)))
depth -= 1
else:
x = Type(None)
return x
def typ(l):
"""
Parses
type(l) = ident «write(ident)» |
"array" «writeln; write((l + 1) * indent + 'array ')» "[" «write('[')» expression ".." «write(' .. ')» expression "]" «write(']')» "of" «write(' of ')» type(l)|
"record" «writeln; write((l + 1) * indent + 'record')» typedIds(l) {";" «write(';')» typedIds(l)} "end" «writeln; write((l + 1) * indent + 'end')».
Returns a type descriptor
"""
if SC.sym not in FIRSTTYPE:
getSym()
mark("type expected")
while SC.sym not in FIRSTTYPE | STRONGSYMS | FOLLOWTYPE:
getSym()
if SC.sym == IDENT:
write(SC.val)
ident = SC.val
x = find(ident)
getSym()
if type(x) == Type: x = Type(x.tp)
else:
mark('not a type')
x = Type(None)
elif SC.sym == ARRAY:
writeln()
write((l + 1) * indent + 'array ')
getSym()
if SC.sym == LBRAK:
write('[')
getSym()
else:
mark("'[' expected")
x = expression()
if SC.sym == PERIOD:
write(' .')
getSym()
else:
mark("'.' expected")
if SC.sym == PERIOD:
write('. ')
getSym()
else:
mark("'.' expected")
y = expression()
if SC.sym == RBRAK:
write(']')
getSym()
else:
mark("']' expected")
if SC.sym == OF:
write(' of ')
getSym()
else:
mark("'of' expected")
z = typ(l + 1).tp
if type(x) != Const or x.val < 0:
mark('bad lower bound')
x = Type(None)
elif type(y) != Const or y.val < x.val:
mark('bad upper bound')
y = Type(None)
else:
x = Type(CG.genArray(Array(z, x.val, y.val - x.val + 1)))
elif SC.sym == RECORD:
writeln()
write((l + 1) * indent + 'record ')
writeln()
write((l + 2) * indent)
getSym()
openScope()
typedIds(Var, l + 2)
while SC.sym == SEMICOLON:
write(';')
writeln()
write((l + 2) * indent)
getSym()
typedIds(Var, l + 2)
if SC.sym == END:
writeln()
write((l + 1) * indent + 'end')
getSym()
else:
mark("'end' expected")
r = topScope()
closeScope()
x = Type(CG.genRec(Record(r)))
else:
x = Type(None)
return x