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 factor():
"""
Parses
factor = ident selector | integer | "(" expression ")" | "not" factor.
Generates code for the factor if no error is reported
"""
if SC.sym not in FIRSTFACTOR:
mark("factor expected"); getSym()
while SC.sym not in FIRSTFACTOR | STRONGSYMS | FOLLOWFACTOR:
getSym()
if SC.sym == IDENT:
x = find(SC.val)
if type(x) in {Var, Ref}: x = genVar(x)
elif type(x) == Const: x = Const(x.tp, x.val); x = genConst(x)
else: mark('variable or constant expected')
getSym(); x = selector(x)
elif SC.sym == NUMBER:
x = Const(Int, SC.val); x = genConst(x); getSym()
elif SC.sym == LPAREN:
getSym(); x = expression()
if SC.sym == RPAREN: getSym()
else: mark(") expected")
elif SC.sym == NOT:
getSym(); x = factor()
if x.tp != Bool: mark('not boolean')
elif type(x) == Const: x.val = 1 - x.val # constant folding
else: x = genUnaryOp(NOT, x)
else:
mark("factor expected"); x = None
return x
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():
"""
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 factor():
"""
Parses
factor = ident selector | integer | "(" expression ")" | "not" factor.
Generates code for the factor if no error is reported
"""
if SC.sym not in FIRSTFACTOR:
mark("factor expected", 8)
getSym()
while SC.sym not in FIRSTFACTOR | STRONGSYMS | FOLLOWFACTOR:
getSym()
if SC.sym == IDENT:
x = find(SC.val)
if type(x) in {Var, Ref}: x = genVar(x)
elif type(x) == Const:
x = Const(x.tp, x.val)
x = genConst(x)
else:
mark('variable or constant expected', 9)
getSym()
x = selector(x)
elif SC.sym == NUMBER:
x = Const(Int, SC.val)
x = genConst(x)
getSym()
elif SC.sym == LPAREN:
getSym()
x = expression()
if SC.sym == RPAREN: getSym()
else: mark(") expected", 10)
elif SC.sym == NOT:
getSym()
x = factor()
if x.tp != Bool: mark('not boolean', 11)
elif type(x) == Const: x.val = 1 - x.val # constant folding
else: x = genUnaryOp(NOT, x)
else:
mark("factor expected", 12)
x = None
return x
def factor():
"""
Parses
factor = ident «write(ident)» selector |
integer «write(integer)» |
"(" «write('(')» expression ")" «write(')')» |
"not" «write('not ') factor.
Generates code for the factor if no error is reported
"""
if SC.sym not in FIRSTFACTOR:
mark("expression expected")
getSym()
while SC.sym not in FIRSTFACTOR | STRONGSYMS | FOLLOWFACTOR:
getSym()
if SC.sym == IDENT:
x = find(SC.val)
if type(x) in {Var, Ref}: x = CG.genVar(x)
elif type(x) == Const:
x = Const(x.tp, x.val)
x = CG.genConst(x)
else:
mark('expression expected')
write(SC.val)
writeHtml(SC.val)
getSym()
x = selector(x)
elif SC.sym == NUMBER:
x = Const(Int, SC.val)
x = CG.genConst(x)
write(str(SC.val))
writeHtml(str(SC.val))
getSym()
elif SC.sym == LPAREN:
write('(')
writeHtml('(')
getSym()
x = expression()
if SC.sym == RPAREN:
write(')')
writeHtml(')')
getSym()
else:
mark(") expected")
elif SC.sym == NOT:
write('not ')
writeHtml('not ')
getSym()
x = factor()
if x.tp != Bool: mark('not boolean')
elif type(x) == Const: x.val = 1 - x.val # constant folding
else: x = CG.genUnaryOp(NOT, x)
else: x = Const(None, 0)
return x
def factor():
if SC.sym not in FIRSTFACTOR:
mark("expression expected")
getSym()
while SC.sym not in FIRSTFACTOR | STRONGSYMS | FOLLOWFACTOR:
getSym()
if SC.sym == IDENT:
x = find(SC.val)
if type(x) in {Var, Ref}: x = CG.genVar(x)
elif type(x) == Const:
x = Const(x.tp, x.val)
x = CG.genConst(x)
else:
mark('expression expected')
getSym()
x = selector(x)
elif SC.sym == NUMBER:
x = Const(Int, SC.val)
x = CG.genConst(x)
getSym()
elif SC.sym == LPAREN:
getSym()
x = expression()
if SC.sym == RPAREN: getSym()
else: mark(") expected")
elif SC.sym == NOT:
getSym()
x = factor()
if x.tp != Bool: mark('not boolean')
elif type(x) == Const: x.val = 1 - x.val # constant folding
else: x = CG.genUnaryOp(NOT, x)
elif SC.sym == TILDE:
getSym()
x = factor()
if x.tp != Int: mark('not integer')
elif type(x) == Const: x.val = ~x.val # constant folding
else: x = CG.genUnaryOp(TILDE, x)
else: x = Const(None, 0)
return x
def factor():
if SC.sym == IDENT:
x = find(SC.val)
if type(x) == Var: x = CG.genVar(x); getSym()
elif type(x) == Const: x = Const(x.tp, x.val); x = CG.genConst(x); getSym()
else: mark('variable or constant identifier expected')
x = selector(x)
elif SC.sym == NUMBER:
x = Const(Int, SC.val); x = CG.genConst(x); getSym()
elif SC.sym == LPAREN:
getSym(); x = expression()
if SC.sym == RPAREN: getSym()
else: mark(') expected')
elif SC.sym == LBRACE:
getSym()
if SC.sym in FIRSTEXPRESSION:
y = expression()
if y.tp == Int: x = CG.genUnaryOp(SET, y)
else: mark('not integer')
while SC.sym == COMMA:
getSym(); y = expression()
if y.tp == Int: y = CG.genUnaryOp(SET, y)
else: mark("not integer")
x = CG.genBinaryOp(UNION, x, y)
else: x = Const(Set(0, 32), 0); x = CG.genConst(x)
if SC.sym == RBRACE: getSym()
else: mark('} expected')
elif SC.sym == NOT:
getSym(); x = factor()
if x.tp != Bool: mark('not boolean')
elif type(x) == Const: x.val = 1 - x.val # constant folding
else: x = CG.genUnaryOp(NOT, x)
elif SC.sym in {CARD, COMPLEMENT}:
op = SC.sym; getSym(); x = factor()
if type(x.tp) == Set: x = CG.genUnaryOp(op, x)
else: mark('set expected')
else: mark('expression expected')
return x