class Parser:
"""Turn the C input file into a tree of expressions and statements."""
def __init__(self, input_file, reuse, initialize_memory):
self.symbols_defined_in_current_scope = {}
self.symbols_defined_stack = []
self.scope = {}
self.scope_stack = []
self.function = None
self.loop = None
self.tokens = Tokens(input_file)
self.allocator = Allocator(reuse)
self.structs = []
self.initialize_memory = initialize_memory
def add_to_scope(self, name, obj):
#if the name has already been defined in the current scope, error out.
if name in self.symbols_defined_in_current_scope:
self.tokens.error("%s is already defined"%name)
self.symbols_defined_in_current_scope[name]=obj
self.scope[name]=obj
def enter_scope(self):
self.symbols_defined_stack.append(self.symbols_defined_in_current_scope) #stack holds everything that has been defined in a underlying scope
self.scope_stack.append(copy(self.scope))
self.symbols_defined_in_current_scope = {}
def leave_scope(self):
self.symbols_defined_in_current_scope = self.symbols_defined_stack.pop()
self.scope = self.scope_stack.pop()
def parse_process(self):
process = Process()
process.allocator = self.allocator
process.inputs = []
process.outputs = []
process.functions = []
while not self.tokens.end():
if self.tokens.peek() == "struct":
self.parse_define_struct()
elif self.tokens.peek() == "typedef":
self.parse_typedef_struct()
else:
function = self.parse_function()
if function is not None:
process.functions.append(function)
process.main = self.main
return process
def parse_type_specifier(self):
type_specifiers = []
while self.tokens.peek() in types + self.structs + storage_specifiers:
type_specifiers.append(self.tokens.get())
signed = True
if "unsigned" in type_specifiers:
signed = False
if "signed" in type_specifiers:
self.tokens.error("Cannot be signed and unsigned")
size = 2
if "long" in type_specifiers:
if "short" in type_specifiers:
self.tokens.error("Cannot be long and short")
size = 4
type_ = "int"
for i in type_specifiers:
if i in self.structs:
type_ = i
size = 2
signed = False
if "float" in type_specifiers:
if "short" in type_specifiers:
self.tokens.error("Float cannot be short")
if "long" in type_specifiers:
self.tokens.error("Float cannot be long (but double can)")
if "unsigned" in type_specifiers:
self.tokens.error("Float cannot be unsigned")
type_ = "float"
size = 4
signed = True
const = False
if "const" in type_specifiers:
const = True
if "void" in type_specifiers:
type_ = "void"
size = 2
signed = False
return type_, size, signed, const
def parse_argument(self):
type_, size, signed, const = self.parse_type_specifier()
if type_ in ["void"]:
self.tokens.error("argument cannot be void")
else:
argument = self.tokens.get()
if type_ in self.structs:
declaration = self.scope[type_]
else:
if self.tokens.peek() == "[":
self.tokens.expect("[")
self.tokens.expect("]")
declaration = ArrayDeclaration(
self.allocator,
2,
type_+"[]",
type_,
size,
signed,
None,
self.initialize_memory)
else:
declaration = VariableDeclaration(
self.allocator,
None,
argument,
type_,
size,
signed,
const)
instance = declaration.instance()
return (argument, instance)
#self.add_to_scope(argument,instance)
#return instance.reference()
def parse_function(self):
type_, size, signed, const = self.parse_type_specifier()
name = self.tokens.get()
#check if it is a global declaration
if self.tokens.peek() != "(":
return self.parse_global_declaration(type_, size, signed, const, name)
#otherwise continue parsing a function
function_was_already_declared = False
if name in self.scope:
#something already has the same name
function_was_already_declared = True
function = self.scope[name]
if not isinstance(function, Function):
self.tokens.error("%s was already mentioned, but was not a function"%name)
#check if return type matches
if function.type_ != type_:
self.tokens.error("return type of %s does not match the previously declared type; is %s, should be %s"%(name, type_, function.type_))
if function.size != size:
self.tokens.error("size of return type of %s does not match the previously declared size; is %s, should be %s"%(name, size, function.size))
if function.signed != signed:
self.tokens.error("signedness of return type of %s does not match the previously declared signedness; is %s, should be %s"%(name, signed, function.signed))
if function.const != const:
self.tokens.error("constness of return type of %s does not match the previously declared constness; is %s, should be %s"%(name, const, function.const))
else:
#first time this name is seen
function = Function()
function.allocator = self.allocator
function.name = name
function.type_ = type_
function.size = size
function.signed = signed
function.const = const
function.return_address = self.allocator.new(2,
function.name+" return address")
if type_ != "void":
if type_ in self.structs:
declaration = self.scope[type_]
else:
if self.tokens.peek() == "[":
self.tokens.error(
"Functions cannot return arrays")
#if functions are changed to allow returning arrays, then check here if it matches the forward declaration, if any.
else:
declaration = VariableDeclaration(
self.allocator,
None,
function.name+" return value",
type_,
size,
signed,
const)
function.return_value = declaration.instance().reference()
self.tokens.expect("(")
#arguments must be allocated the first time the function is mentioned.
#because when other functions call this function, they need to use the allocated variables
#so don't allocate argument variables any time except the first time
#the next time you encounter this function, only check if the arguments are the correct type
#Also, don't add the argument variables to the current scope unless you have an argument body, because the names can change.
if not function_was_already_declared:
function.arguments = []
function.argument_names = [] #Gets overwritten if the names are changed
while self.tokens.peek() != ")":
(arg_name, instance) = self.parse_argument()
function.arguments.append(instance.reference())
function.argument_names.append(arg_name)
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
else:
#function was already declared
#check if arg types match
function.argument_names = [] #Gets overwritten if the names are changed
for index, argumentVarRef in enumerate(function.arguments):
if self.tokens.peek() != ")":
#next section is ugly
#a better way would be a function to compare 2 types for exact equality
argumentInst = argumentVarRef.instance
arg_type, arg_size, arg_signed, arg_const = self.parse_type_specifier()
arg_name = self.tokens.get()
#print "%s: type %s, size %s, signed %s, const %s"%(arg_name, arg_type, arg_size, arg_signed, arg_const)
function.argument_names.append(arg_name)
is_array = False
if self.tokens.peek() == "[":
self.tokens.expect("[")
self.tokens.expect("]")
is_array = True
arg_type = arg_type + "[]"
if arg_type != argumentInst.type_():
self.tokens.error("Function %s, argument %d, was previously declared to have type %s, but here, it is %s"%(name, index+1, argumentInst.type_(), arg_type))
if not is_array:
if arg_size != argumentInst.size():
self.tokens.error("Function %s, argument %d, was previously declared to have size %s, but here, it is %s"%(name, index+1, argumentInst.size(), arg_size))
if arg_const != argumentInst.const():
self.tokens.error("Function %s, argument %d, was previously declared to have constness %s, but here, it is %s"%(name, index+1, argumentInst.const(), arg_const))
if arg_signed != argumentInst.signed():
self.tokens.error("Function %s, argument %d, was previously declared to have signedness %s, but here, it is %s"%(name, index+1, argumentInst.signed(), arg_signed))
else:
if arg_size != argumentInst.element_size:
self.tokens.error("Function %s, argument %d, was previously declared to have element size %s, but here, it is %s"%(name, index+1, argumentInst.element_size, arg_size))
if arg_signed != argumentInst.element_signed:
self.tokens.error("Function %s, argument %d, was previously declared to have element signedness %s, but here, it is %s"%(name, index+1, argumentInst.element_signed, arg_signed))
#array element constness?
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
self.tokens.error("Function %s was previously declared to have %d arguments, but here, only %d are present"%(name, len(function.arguments), index))
if self.tokens.peek() != ")":
self.tokens.error("Function %s was previously declared to have %d arguments, but here, more are present"%(name, len(function.arguments) ))
#print function.arguments
self.tokens.expect(")")
if self.tokens.peek() == ";":
self.tokens.expect(";")
else:
self.enter_scope()
self.function = function
#body attached - add the argument variables to the new scope
for (arg_name, argumentVarRef) in zip(function.argument_names, function.arguments):
self.add_to_scope(arg_name, argumentVarRef.instance)
if function.statement is not None:
self.tokens.error("A function body was already defined for %s, can't use another"%name)
function.statement = self.parse_block()
if type_ != "void" and not hasattr(function, "return_statement"):
self.tokens.error("Function must have a return statement")
self.function = None
self.leave_scope() #now we are done parsing the function, restore the previous scope
if not function_was_already_declared:
self.add_to_scope(function.name,function)
#main thread is last function
self.main = function
if function_was_already_declared:
return None #The function object is returned upon the function's first mention, so here, return something that will not generate any code
return function
def parse_break(self):
break_ = Break()
break_.loop = self.loop
self.tokens.expect("break")
self.tokens.expect(";")
return break_
def parse_continue(self):
continue_ = Continue()
continue_.loop = self.loop
self.tokens.expect("continue")
self.tokens.expect(";")
return continue_
def parse_return(self):
return_ = Return()
return_.function = self.function
return_.allocator = self.allocator
self.function.return_statement = return_
self.tokens.expect("return")
if hasattr(self.function, "return_value"):
expression = self.parse_expression()
if self.function.type_ == "int" and expression.type_() == "float":
expression = FloatToInt(expression)
elif self.function.type_ == "float" and expression.type_() == "int":
expression = IntToFloat(expression)
elif self.function.type_ != expression.type_():
self.tokens.error(
"type mismatch in return statement expected: %s actual: %s"%(
self.function.type_,
expression.type_()))
return_.expression = expression
self.tokens.expect(";")
return return_
def parse_assert(self):
assert_ = Assert()
assert_.allocator = self.allocator
self.tokens.expect("assert")
self.tokens.expect("(")
assert_.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
assert_.line = self.tokens.lineno
assert_.filename = self.tokens.filename
return assert_
def parse_report(self):
report_ = Report()
report_.allocator = self.allocator
self.tokens.expect("report")
self.tokens.expect("(")
report_.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
report_.line = self.tokens.lineno
report_.filename = self.tokens.filename
return report_
def parse_wait_clocks(self):
wait_clocks = WaitClocks()
wait_clocks.allocator = self.allocator
self.tokens.expect("wait_clocks")
self.tokens.expect("(")
wait_clocks.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
wait_clocks.line = self.tokens.lineno
return wait_clocks
def parse_statement(self):
if self.tokens.peek() in numeric_types + self.structs + storage_specifiers:
return self.parse_compound_declaration()
elif self.tokens.peek() == "struct":
return self.parse_struct_declaration()
elif self.tokens.peek() == "if":
return self.parse_if()
elif self.tokens.peek() == "while":
return self.parse_while()
elif self.tokens.peek() == "for":
return self.parse_for()
elif self.tokens.peek() == "return":
return self.parse_return()
elif self.tokens.peek() == "break":
return self.parse_break()
elif self.tokens.peek() == "continue":
return self.parse_continue()
elif self.tokens.peek() == "{":
return self.parse_block()
elif self.tokens.peek() == "assert":
return self.parse_assert()
elif self.tokens.peek() == "report":
return self.parse_report()
elif self.tokens.peek() == "switch":
return self.parse_switch()
elif self.tokens.peek() == "case":
return self.parse_case()
elif self.tokens.peek() == "default":
return self.parse_default()
elif self.tokens.peek() == "wait_clocks":
return self.parse_wait_clocks()
elif self.tokens.peek() == "goto":
return self.parse_goto();
elif self.tokens.peek(1) == ":":
return self.parse_labeled_statement()
else:
expression = self.parse_discard()
self.tokens.expect(";")
return expression
def parse_discard(self):
return DiscardExpression(self.parse_expression(), self.allocator)
def parse_labeled_statement(self):
name = self.tokens.get()
self.tokens.expect(":")
label = Label(name, self.parse_statement() )
if name in self.function.labels_in_scope:
self.tokens.error(
"label %s was already declared in this function"%name)
self.function.labels_in_scope[name] = label
return label
def parse_goto(self):
self.tokens.expect("goto")
name = self.tokens.get()
self.tokens.expect(";")
return Goto(name, self.function, self.tokens.filename, self.tokens.lineno)
def parse_assignment(self):
assignment_operators = [
"=", "+=", "-=", "*=", "/=", "%=", "&=", "|=", "^=", "<<=", ">>="
]
lvalue = self.parse_ternary_expression()
if self.tokens.peek() in assignment_operators:
if lvalue.const():
self.tokens.error(
"left hand operand of assignment is not modifiable")
operator = self.tokens.get()
if operator == "=":
expression = self.parse_ternary_expression()
else:
expression = self.parse_ternary_expression()
left = lvalue
left, expression = self.coerce_types(left, expression)
expression = Binary(operator[:-1], left, expression)
if expression.type_() != lvalue.type_():
if expression.type_() == "int" and lvalue.type_() == "float":
expression = IntToFloat(expression)
elif expression.type_() == "float" and lvalue.type_() == "int":
expression = FloatToInt(expression)
else:
self.tokens.error(
"type mismatch in assignment expected: %s actual: %s"%(
lvalue.type_(),
expression.type_()))
return Assignment(lvalue, expression, self.allocator)
else:
return lvalue
def parse_if(self):
if_ = If()
if_.allocator = self.allocator
self.tokens.expect("if")
self.tokens.expect("(")
if_.expression = self.parse_expression()
if if_.expression.type_() not in ["unsigned", "int", "short", "long", "char"]:
self.tokens.error(
"if statement conditional must be an integer like expression")
self.tokens.expect(")")
if_.true_statement = self.parse_statement()
if self.tokens.peek() == "else":
self.tokens.expect("else")
if_.false_statement = self.parse_statement()
else:
if_.false_statement = None
return if_
def parse_switch(self):
switch = Switch()
switch.cases = {}
self.tokens.expect("switch")
self.tokens.expect("(")
expression = self.parse_expression()
if expression.type_() not in ["unsigned", "int", "short", "long", "char"]:
self.tokens.error(
"switch statement expression must be an integer like expression")
self.tokens.expect(")")
stored_loop = self.loop
self.loop = switch
statement = self.parse_statement()
self.loop = stored_loop
switch.expression = expression
switch.allocator = self.allocator
switch.statement = statement
return switch
def parse_case(self):
self.tokens.expect("case")
expression = self.parse_expression()
if expression.type_() not in ["int"]:
self.tokens.error(
"case expression must be an integer like expression")
self.tokens.expect(":")
try:
expression = expression.value()
case = Case()
self.loop.cases[expression] = case
except NotConstant:
self.tokens.error("case expression must be constant")
except AttributeError:
self.tokens.error(
"case statements may only be use inside a switch statment")
return case
def parse_default(self):
self.tokens.expect("default")
self.tokens.expect(":")
default = Default()
if not hasattr(self.loop, "cases"):
self.tokens.error(
"default statements may only be used inside a switch statment")
if hasattr(self.loop, "default"):
self.tokens.error(
"A switch statement may only have one default statement")
self.loop.default=default
return default
def parse_while(self):
loop = Loop()
self.tokens.expect("while")
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
stored_loop = self.loop
self.loop = loop
statement = self.parse_statement()
self.loop = stored_loop
if_ = If()
loop.statement = if_
break_ = Break()
break_.loop = loop
if_.allocator = self.allocator
if expression.type_() not in ["int"]:
self.tokens.error(
"while statement conditional must be an integer like expression")
if_.expression = expression
if_.false_statement = break_
if_.true_statement = statement
return loop
def parse_for(self):
for_ = For()
for_.allocator = self.allocator
self.tokens.expect("for")
self.tokens.expect("(")
if self.tokens.peek() != ";":
for_.statement1 = self.parse_discard()
self.tokens.expect(";")
if self.tokens.peek() != ";":
for_.expression = self.parse_expression()
if for_.expression.type_() not in [
"unsigned",
"int",
"short",
"long",
"char"]:
self.tokens.error(
"For statement conditional must be an integer like expression")
self.tokens.expect(";")
if self.tokens.peek() != ")":
for_.statement2 = self.parse_discard()
self.tokens.expect(")")
stored_loop = self.loop
self.loop = for_
for_.statement3 = self.parse_statement()
self.loop = stored_loop
return for_
def parse_block(self):
block = Block()
self.enter_scope()
self.tokens.expect("{")
block.statements = []
while self.tokens.peek() != "}":
block.statements.append(self.parse_statement())
self.tokens.expect("}")
self.leave_scope() #now we are done parsing the block, restore the previous scope
return block
def parse_struct_body(self):
self.tokens.expect("{")
members = {}
while self.tokens.peek() != "}":
type_, size, signed, const = self.parse_type_specifier()
name = self.tokens.get()
members[name] = self.parse_declaration(
type_,
size,
signed,
const,
name)
self.tokens.expect(";")
self.tokens.expect("}")
return members
def parse_typedef_struct(self):
self.tokens.expect("typedef")
self.tokens.expect("struct")
declaration = StructDeclaration(self.parse_struct_body())
name = self.tokens.get()
self.tokens.expect(";")
self.add_to_scope(name,declaration)
self.structs.append(name)
def parse_define_struct(self):
self.tokens.expect("struct")
name = self.tokens.get()
declaration = StructDeclaration(self.parse_struct_body())
self.tokens.expect(";")
self.add_to_scope(name,declaration)
def parse_struct_declaration(self):
self.tokens.expect("struct")
struct_name = self.tokens.get()
name = self.tokens.get()
self.tokens.expect(";")
instance = self.scope[struct_name].instance()
self.add_to_scope(name,instance)
return instance
def parse_global_declaration(self, type_, size, signed, const, name):
instances = []
while True:
instance = self.parse_declaration(
type_,
size,
signed,
const,
name).instance()
self.add_to_scope(name,instance)
instances.append(instance)
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
name = self.tokens.get()
self.tokens.expect(";")
return CompoundDeclaration(instances)
def parse_compound_declaration(self):
type_, size, signed, const = self.parse_type_specifier()
instances = []
while True:
name = self.tokens.get()
instance = self.parse_declaration(
type_,
size,
signed,
const,
name).instance()
self.add_to_scope(name,instance)
instances.append(instance)
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
name = None
self.tokens.expect(";")
return CompoundDeclaration(instances)
def parse_declaration(self, type_, size, signed, const, name):
#struct declaration
if type_ in self.structs:
declaration = self.scope[type_]
elif type_ in ["int", "float"]:
#array declaration
if self.tokens.peek() == "[":
array_size = None
self.tokens.expect("[")
if self.tokens.peek() != "]":
size_expression = self.parse_ternary_expression()
if size_expression.type_() != "int":
self.tokens.error("Array size must be an integer like expression")
try:
array_size = size_expression.value()
except NotConstant:
self.tokens.error("Array size must be constant")
self.tokens.expect("]")
initializer = None
if self.tokens.peek() == "=":
self.tokens.expect("=")
initializer = self.tokens.get()
initializer = [ord(i) for i in initializer.strip('"').decode("string_escape")] + [0]
array_size = len(initializer)
if array_size is None:
self.tokens.error(
"array size must be specified if not initialized")
array_type=type_+"[]"
initialize_memory = self.initialize_memory
declaration = ArrayDeclaration(
self.allocator,
array_size,
array_type,
type_,
size,
signed,
initializer,
self.initialize_memory)
#simple variable declaration
else:
if self.tokens.peek() == "=":
self.tokens.expect("=")
initializer = self.parse_ternary_expression()
else:
initializer = Constant(0, type_, size, signed)
if type_ != initializer.type_():
if type_ == "int" and initializer.type_() == "float":
initializer = FloatToInt(initializer)
elif type_ == "float" and initializer.type_() == "int":
initializer = IntToFloat(initializer)
else:
self.tokens.error(
"type mismatch in intializer expected: %s actual: %s"%(
type_,
intitializer.type_()))
declaration = VariableDeclaration(
self.allocator,
initializer,
name,
type_,
size,
signed,
const
)
return declaration
def parse_expression(self):
expression = self.parse_assignment()
return expression
def parse_ternary_expression(self):
expression = constant_fold(self.parse_or_expression())
while self.tokens.peek() in ["?"]:
self.tokens.expect("?")
true_expression = constant_fold(self.parse_or_expression())
self.tokens.expect(":")
false_expression = constant_fold(self.parse_or_expression())
expression = OR(AND(expression, true_expression), false_expression)
return expression
def parse_or_expression(self):
expression = self.parse_and_expression()
while self.tokens.peek() in ["||"]:
self.tokens.expect("||")
expression = OR(expression, self.parse_and_expression())
return expression
def parse_and_expression(self):
expression = self.parse_binary_expression(["|"])
while self.tokens.peek() in ["&&"]:
self.tokens.expect("&&")
expression = AND(expression, self.parse_binary_expression(["|"]))
return expression
def substitute_function(self, binary_expression):
"""
For some operations are more easily implemented in software.
This function substitutes a call to the builtin library function.
"""
functions = {
"False,int,int,4,/" : "long_unsigned_divide_xxxx",
"True,int,int,4,/" : "long_divide_xxxx",
"False,int,int,2,/" : "unsigned_divide_xxxx",
"True,int,int,2,/" : "divide_xxxx",
"False,int,int,4,%" : "long_unsigned_modulo_xxxx",
"True,int,int,4,%" : "long_modulo_xxxx",
"False,int,int,2,%" : "unsigned_modulo_xxxx",
"True,int,int,2,%" : "modulo_xxxx",
"True,float,float,4,==" : "float_equal_xxxx",
"True,float,float,4,!=" : "float_ne_xxxx",
"True,float,float,4,<" : "float_lt_xxxx",
"True,float,float,4,>" : "float_gt_xxxx",
"True,float,float,4,<=" : "float_le_xxxx",
"True,float,float,4,>=" : "float_ge_xxxx",
}
#select a function that matches the template.
signature = ",".join([
str(binary_expression.signed()),
binary_expression.left.type_(),
binary_expression.right.type_(),
str(binary_expression.size()),
binary_expression.operator])
#Some things can't be implemented in verilog, substitute them with a function
if signature in functions:
function = self.scope[functions[signature]]
function_call = FunctionCall(function)
function_call.arguments = [binary_expression.left, binary_expression.right]
return function_call
else:
return binary_expression
def coerce_types(self, left, right):
"""
Convert numeric types in expressions.
"""
if left.type_() != right.type_():
if left.type_() == "float" and right.type_() == "int":
return left, IntToFloat(right)
elif left.type_() == "int" and right.type_() == "float":
return IntToFloat(left), right
else:
self.tokens.error("Incompatible types : %s %s"%(
left.type_(),
right.type_()))
return left, right
def parse_binary_expression(self, operators):
operator_precedence = {
"|": ["^"],
"^": ["&"],
"&": ["==", "!="],
"==": ["<", ">", "<=", ">="],
"<": ["<<", ">>"],
"<<": ["+", "-"],
"+": ["*", "/", "%"],
}
if operators[0] not in operator_precedence:
left = self.parse_unary_expression()
while self.tokens.peek() in operators:
operator = self.tokens.get()
right = self.parse_unary_expression()
left, right = self.coerce_types(left, right)
left = Binary(operator, left, right)
left = self.substitute_function(left)
return left
else:
next_operators = operator_precedence[operators[0]]
left = self.parse_binary_expression(next_operators)
while self.tokens.peek() in operators:
operator = self.tokens.get()
right = self.parse_binary_expression(next_operators)
left, right = self.coerce_types(left, right)
left = Binary(operator, left, right)
left = self.substitute_function(left)
return left
def parse_unary_expression(self):
if self.tokens.peek() == "!":
operator = self.tokens.get()
expression = self.parse_postfix_expression()
if expression.type_() not in ["int"]:
self.tokens.error(
"! is only valid for integer like expressions")
return Binary("==", expression, Constant(0))
elif self.tokens.peek() == "-":
operator = self.tokens.get()
expression = self.parse_postfix_expression()
return Binary("-", Constant(0,
expression.type_(),
expression.size(),
expression.signed()),
expression)
elif self.tokens.peek() == "~":
operator = self.tokens.get()
expression = self.parse_postfix_expression()
if expression.type_() not in ["int"]:
self.tokens.error(
"~ is only valid for integer like expressions")
return Unary("~", expression)
elif self.tokens.peek() == "sizeof":
operator = self.tokens.get()
expression = self.parse_unary_expression()
return SizeOf(expression)
else:
return self.parse_postfix_expression()
def parse_postfix_expression(self):
expression = self.parse_paren_expression()
while self.tokens.peek() in ["++", "--"]:
operator = self.tokens.get()
expression = PostIncrement(
operator[:-1],
expression,
self.allocator
)
return expression
def parse_paren_expression(self):
if self.tokens.peek() == "(":
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
else:
expression = self.parse_number_or_variable()
return expression
def parse_number_or_variable(self):
if self.tokens.peek()[0].isalpha():
name = self.tokens.get()
if self.tokens.peek() == "(":
return self.parse_function_call(name)
else:
return self.parse_variable(name)
else:
return self.parse_number()
def parse_file_read(self):
self.tokens.expect("(")
file_name = self.tokens.get()
file_name = file_name.strip('"').decode("string_escape")
self.tokens.expect(")")
return FileRead(file_name)
def parse_file_write(self):
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(",")
file_name = self.tokens.get()
file_name = file_name.strip('"').decode("string_escape")
self.tokens.expect(")")
return FileWrite(file_name, expression)
def parse_input(self, name):
input_name = name.replace("input_", "")
self.tokens.expect("(")
type_ = "int"
if self.tokens.peek() != ")":
type_ = self.tokens.get()
type_ = type_.strip('"').decode("string_escape")
if type_ not in numeric_types:
self.tokens.error("%s is not a numeric type"%type_)
self.tokens.expect(")")
return Input(input_name, type_)
def parse_ready(self, name):
input_name = name.replace("ready_", "")
self.tokens.expect("(")
self.tokens.expect(")")
return Ready(input_name)
def parse_output(self, name):
output_name = name.replace("output_", "")
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
return Output(output_name, expression)
def parse_function_call(self, name):
if name.startswith("input_"):
return self.parse_input(name)
if name.startswith("ready_"):
return self.parse_ready(name)
if name.startswith("output_"):
return self.parse_output(name)
if name == "file_read":
return self.parse_file_read()
if name == "file_write":
return self.parse_file_write()
if name not in self.scope:
self.tokens.error("Unknown function: %s"%name)
function = self.scope[name]
function_call = FunctionCall(function)
function_call.arguments = []
self.tokens.expect("(")
while self.tokens.peek() != ")":
function_call.arguments.append(self.parse_expression())
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
self.tokens.expect(")")
required_arguments = len(function_call.function.arguments)
actual_arguments = len(function_call.arguments)
if required_arguments != actual_arguments:
self.tokens.error("Function %s takes %s arguments, %s given."%(
name,
len(function_call.function.arguments),
len(function_call.arguments)))
required_arguments = function_call.function.arguments
actual_arguments = function_call.arguments
corrected_arguments = []
for required, actual in zip(required_arguments, actual_arguments):
if not compatible(required, actual):
if actual.type_() == "int" and required.type_() == "float":
actual = IntToFloat(actual)
elif actual.type_() == "float" and required.type_() == "int":
actual = FloatToInt(actual)
else:
self.tokens.error(
"type mismatch in assignment expected: %s, actual: %s"%(
required.type_(),
actual.type_()))
corrected_arguments.append(actual)
function_call.arguments = corrected_arguments
return function_call
def parse_number(self):
token = self.tokens.get()
type_ = "int"
size = 2
signed = True
if token.startswith("'"):
try:
token = eval(token)
value = ord(token)
except SyntaxError:
self.tokens.error("%s is not a character literal"%token)
elif token.startswith('"'):
try:
initializer = [ord(i) for i in token.strip('"').decode("string_escape")] + [0]
size = len(initializer)
initialize_memory = self.initialize_memory
declaration = ArrayDeclaration(
self.allocator,
size,
"int[]",
"int",
2,
False,
initializer,
self.initialize_memory)
return ConstArray(declaration.instance())
except SyntaxError:
self.tokens.error("%s is not a character literal"%token)
elif "." in token:
#float literal
try:
type_ = "float"
signed = True
size = 4
token = token.upper().replace("F", "")
token = token.upper().replace("L", "")
value = float(eval(token))
try:
byte_value = struct.pack(">f", value)
except OverflowError:
self.tokens.error("value too large")
except SyntaxError:
self.tokens.error("%s is not a floating point literal"%token)
else:
#integer literal
try:
if "U" in token.upper():
signed = False
if "L" in token.upper():
size = 4
token = token.upper().replace("U", "")
value = int(eval(token))
if signed:
if value > 2**((size * 8)-1) - 1:
self.tokens.error("value too large")
if value < -(2**((size * 8)-1)):
self.tokens.error("value too small")
else:
if value > 2**(size * 8) - 1:
self.tokens.error("value too large")
if value < 0:
self.tokens.error("value too small")
except SyntaxError:
self.tokens.error("%s is not an integer literal"%token)
return Constant(value, type_, size, signed)
def parse_variable(self, name):
if name not in self.scope:
self.tokens.error("Unknown variable: %s"%name)
instance = self.scope[name]
return self.parse_variable_array_struct(instance)
def parse_variable_array_struct(self, instance):
if instance.type_() in numeric_types:
if not hasattr(instance, "reference"):
self.tokens.error(
"Not an expression")
return Variable(instance)
elif instance.type_().endswith("[]"):
if self.tokens.peek() == "[":
self.tokens.expect("[")
index_expression = self.parse_expression()
self.tokens.expect("]")
if index_expression.type_() not in ["int"]:
self.tokens.error(
"Array indices must be an integer like expression")
return ArrayIndex(instance, index_expression)
else:
return Array(instance)
elif instance.type_().startswith("struct"):
if self.tokens.peek() == ".":
self.tokens.expect(".")
member = self.tokens.get()
instance = instance.members[member]
return self.parse_variable_array_struct(instance)
else:
return Struct(instance)
class Parser:
"""Turn the C input file into a tree of expressions and statements."""
def __init__(self, input_file, reuse):
self.scope = {}
self.function = None
self.loop = None
self.tokens = Tokens(input_file)
self.allocator = Allocator(reuse)
self.structs = []
def parse_process(self):
process = Process()
process.allocator = self.allocator
process.inputs = []
process.outputs = []
process.functions = []
while not self.tokens.end():
if self.tokens.peek() == "struct":
self.parse_define_struct()
elif self.tokens.peek() == "typedef":
self.parse_typedef_struct()
else:
process.functions.append(self.parse_function())
process.main = self.main
return process
def parse_function(self):
function = Function(self.allocator)
stored_scope = self.scope
type_ = self.tokens.get()
name = self.tokens.get()
#check if it is a global declaration
if self.tokens.peek() != "(":
if type_ not in ["int", "short", "long", "char"] + self.structs:
self.tokens.error("unknown type")
return self.parse_global_declaration(type_, name)
#otherwise continue parsing a function
self.tokens.expect("(")
function.name = name
function.type_ = type_
function.return_address = self.allocator.new(function.name+" return address")
if type_ not in ["int", "short", "long", "char", "void"]:
self.tokens.error("unknown type")
if type_ != "void":
function.return_value = self.allocator.new(function.name+" return value")
function.arguments = []
while self.tokens.peek() != ")":
type_ = self.tokens.get()
if type_ not in ["int", "short", "long", "char"]:
self.tokens.error("unknown type")
argument = self.tokens.get()
if self.tokens.peek() == "[":
self.tokens.expect("[")
self.tokens.expect("]")
type_+="[]"
function.arguments.append(Argument(argument, type_, self))
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
self.tokens.expect(")")
self.function = function
function.statement = self.parse_statement()
if type_ != "void" and not hasattr(function, "return_statement"):
self.tokens.error("Function must have a return statement")
self.function = None
self.scope = stored_scope
self.scope[function.name] = function
#main thread is last function
self.main = function
return function
def parse_break(self):
break_ = Break()
break_.loop = self.loop
self.tokens.expect("break")
self.tokens.expect(";")
return break_
def parse_continue(self):
continue_ = Continue()
continue_.loop = self.loop
self.tokens.expect("continue")
self.tokens.expect(";")
return continue_
def parse_return(self):
return_ = Return()
return_.function = self.function
self.function.return_statement = return_
self.tokens.expect("return")
if hasattr(self.function, "return_value"):
return_.expression = self.parse_expression()
self.tokens.expect(";")
return return_
def parse_assert(self):
assert_ = Assert()
assert_.allocator = self.allocator
self.tokens.expect("assert")
self.tokens.expect("(")
assert_.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
assert_.line = self.tokens.lineno
assert_.filename = self.tokens.filename
return assert_
def parse_report(self):
report_ = Report()
report_.allocator = self.allocator
self.tokens.expect("report")
self.tokens.expect("(")
report_.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
report_.line = self.tokens.lineno
report_.filename = self.tokens.filename
return report_
def parse_wait_clocks(self):
wait_clocks = WaitClocks()
wait_clocks.allocator = self.allocator
self.tokens.expect("wait_clocks")
self.tokens.expect("(")
wait_clocks.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
wait_clocks.line = self.tokens.lineno
return wait_clocks
def parse_statement(self):
if self.tokens.peek() in ["int", "short", "long", "char", "bool"] + ["ac_int"] + self.structs:
return self.parse_compound_declaration()
elif self.tokens.peek() == "struct":
return self.parse_struct_declaration()
elif self.tokens.peek() == "if":
return self.parse_if()
elif self.tokens.peek() == "while":
return self.parse_while()
elif self.tokens.peek() == "for":
return self.parse_for()
elif self.tokens.peek() == "return":
return self.parse_return()
elif self.tokens.peek() == "break":
return self.parse_break()
elif self.tokens.peek() == "continue":
return self.parse_continue()
elif self.tokens.peek() == "{":
return self.parse_block()
elif self.tokens.peek() == "assert":
return self.parse_assert()
elif self.tokens.peek() == "report":
return self.parse_report()
elif self.tokens.peek() == "switch":
return self.parse_switch()
elif self.tokens.peek() == "case":
return self.parse_case()
elif self.tokens.peek() == "default":
return self.parse_default()
elif self.tokens.peek() == "wait_clocks":
return self.parse_wait_clocks()
else:
expression = self.parse_discard()
self.tokens.expect(";")
return expression
def parse_discard(self):
return DiscardExpression(self.parse_expression(), self.allocator)
## ...
#
# does also type checking
def parse_assignment(self):
assignment_operators = [
"=", "+=", "-=", "*=", "/=", "%=", "&=", "|=", "<<=", ">>=",
"++", "--"
]
lvalue = self.parse_ternary_expression()
if self.tokens.peek() in assignment_operators:
if not hasattr(lvalue, "declaration"):
self.tokens.error(
"left hand operand of assignment is not modifiable"
)
operator = self.tokens.get()
if operator == "=":
expression = self.parse_ternary_expression()
elif operator in ["++", "--"]:
expression = Binary(
operator[:-1],
lvalue,
Constant(1),
self.allocator
)
else:
expression = Binary(
operator[:-1],
lvalue,
self.parse_ternary_expression(),
self.allocator
)
if lvalue.type_ != expression.type_:
self.tokens.error(
"type mismatch in assignment"
)
return Assignment(lvalue, expression, self.allocator)
else:
return lvalue
def parse_if(self):
if_ = If()
if_.allocator = self.allocator
self.tokens.expect("if")
self.tokens.expect("(")
if_.expression = self.parse_expression()
if if_.expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"if statement conditional must be an integer like expression"
)
self.tokens.expect(")")
if_.true_statement = self.parse_statement()
if self.tokens.peek() == "else":
self.tokens.expect("else")
if_.false_statement = self.parse_statement()
else:
if_.false_statement = None
return if_
def parse_switch(self):
switch = Switch()
switch.cases = {}
self.tokens.expect("switch")
self.tokens.expect("(")
expression = self.parse_expression()
if expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"switch statement expression must be an integer like expression"
)
self.tokens.expect(")")
stored_loop = self.loop
self.loop = switch
statement = self.parse_statement()
self.loop = stored_loop
switch.expression = expression
switch.allocator = self.allocator
switch.statement = statement
return switch
def parse_case(self):
self.tokens.expect("case")
expression = self.parse_expression()
if expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"case expression must be an integer like expression"
)
self.tokens.expect(":")
try:
expression = value(expression)
case = Case()
self.loop.cases[expression] = case
except NotConstant:
self.tokens.error("case expression must be constant")
except AttributeError:
self.tokens.error(
"case statements may only be use inside a switch statment"
)
return case
def parse_default(self):
self.tokens.expect("default")
self.tokens.expect(":")
default = Default()
if not hasattr(self.loop, "cases"):
self.tokens.error(
"default statements may only be used inside a switch statment"
)
if hasattr(self.loop, "default"):
self.tokens.error(
"A switch statement may only have one default statement"
)
self.loop.default=default
return default
def parse_while(self):
loop = Loop()
self.tokens.expect("while")
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
stored_loop = self.loop
self.loop = loop
statement = self.parse_statement()
self.loop = stored_loop
if_ = If()
loop.statement = if_
break_ = Break()
break_.loop = loop
if_.allocator = self.allocator
if expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"if statement conditional must be an integer like expression"
)
if_.expression = expression
if_.false_statement = break_
if_.true_statement = statement
return loop
def parse_for(self):
for_ = For()
for_.allocator = self.allocator
self.tokens.expect("for")
self.tokens.expect("(")
if self.tokens.peek() != ";":
for_.statement1 = self.parse_discard()
self.tokens.expect(";")
if self.tokens.peek() != ";":
for_.expression = self.parse_expression()
if for_.expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"for statement conditional must be an integer like expression"
)
self.tokens.expect(";")
if self.tokens.peek() != ")":
for_.statement2 = self.parse_discard()
self.tokens.expect(")")
stored_loop = self.loop
self.loop = for_
for_.statement3 = self.parse_statement()
self.loop = stored_loop
return for_
def parse_block(self):
block = Block()
stored_scope = self.scope
self.tokens.expect("{")
block.statements = []
while self.tokens.peek() != "}":
block.statements.append(self.parse_statement())
self.tokens.expect("}")
self.scope = stored_scope
return block
def parse_struct_body(self):
self.tokens.expect("{")
members = {}
while self.tokens.peek() != "}":
type_ = self.tokens.get()
name = self.tokens.get()
members[name] = self.parseVariableDeclaration(type_, name)
self.tokens.expect(";")
self.tokens.expect("}")
return members
def parse_typedef_struct(self):
self.tokens.expect("typedef")
self.tokens.expect("struct")
declaration = StructDeclaration(self.parse_struct_body())
name = self.tokens.get()
self.tokens.expect(";")
self.scope[name] = declaration
self.structs.append(name)
def parse_define_struct(self):
self.tokens.expect("struct")
name = self.tokens.get()
declaration = StructDeclaration(self.parse_struct_body())
self.tokens.expect(";")
self.scope[name] = declaration
def parse_struct_declaration(self):
self.tokens.expect("struct")
struct_name = self.tokens.get()
name = self.tokens.get()
self.tokens.expect(";")
instance = self.scope[struct_name].instance()
self.scope[name] = instance
return instance
def parse_global_declaration(self, type_, name):
instances = []
while True:
instance = self.parseVariableDeclaration(type_, name).instance()
self.scope[name] = instance
instances.append(instance)
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
name = self.tokens.get()
self.tokens.expect(";")
return CompoundDeclaration(instances)
def parse_compound_declaration(self):
type_ = self.tokens.get()
if type_ == "ac_int":
if self.tokens.peek() != "<":
self.tokens.error(
"expected template open token \"<\""
)
self.tokens.expect("<")
bracketLevel = 0
innerTokens = []
while True:
if self.tokens.peek() == ">" and bracketLevel == 0:
self.tokens.expect(">")
break
if self.tokens.peek() == ">":
innerTokens.append(">")
self.tokens.expect(">")
bracketLevel -= 1
continue
if self.tokens.peek() == "<":
innerTokens.append("<")
self.tokens.expect("<")
bracketLevel += 1
continue
innerTokens.append(self.tokens.peek())
self.tokens.expect(self.tokens.peek())
# TODO< better error message with a range over the template parameters
if len(innerTokens) != 1:
self.tokens.error(
"expected two number arguments"
)
bitWidth = 0
try:
bitWidth = int(innerTokens[0])
except ValueError:
# TODO< better error message >
self.tokens.error(
"positive integer between 1 and 64 expected!"
)
if bitWidth <= 0 or bitWidth > 64:
# TODO< better error message >
self.tokens.error(
"positive integer between 1 and 64 expected!"
)
# TODO< save bitwidth with type into type information >
instances = []
while True:
name = self.tokens.get()
instance = self.parseVariableDeclaration(type_, name).instance()
self.scope[name] = instance
instances.append(instance)
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
name = None
self.tokens.expect(";")
return CompoundDeclaration(instances)
def parseVariableDeclaration(self, type_, name):
# check for struct declaration
if type_ in self.structs:
declaration = self.scope[type_]
elif type_ in ["int", "short", "long", "char", "bool"]:
# check for array declaration
if self.tokens.peek() == "[":
self.tokens.expect("[")
size = self.tokens.get()
self.tokens.expect("]")
type_+="[]"
declaration = ArrayDeclaration(self.allocator, size, type_)
return declaration
""""
# this parses the template types
# it is for now limited to the systemC like built in types
elif type_ in ["ac_int"]:
if self.tokens.peek() != "<":
self.tokens.error(
"expected template open token \"<\""
)
self.tokens.expect("<")
bracketLevel = 0
innerTokens = []
while True:
if self.tokens.peek() == ">" and bracketLevel == 0:
self.tokens.expect(">")
break
if self.tokens.peek() == ">":
innerTokens.append(">")
self.tokens.expect(">")
bracketLevel -= 1
continue
if self.tokens.peek() == "<":
innerTokens.append("<")
self.tokens.expect("<")
bracketLevel += 1
continue
innerTokens.append(self.tokens.peek())
self.tokens.expect(self.tokens.peek)
# TODO< better error message with a range over the template parameters
if len(innerTokens) != 2:
self.tokens.error(
"expected two number arguments"
)
"""
# simple variable declaration
if self.tokens.peek() == "=":
self.tokens.expect("=")
initializer = self.parse_ternary_expression()
else:
initializer = Constant(0)
declaration = VariableDeclaration(
self.allocator,
initializer,
name,
type_
)
return declaration
def parse_expression(self):
expression = self.parse_assignment()
return expression
def parse_ternary_expression(self):
expression = constant_fold(self.parse_or_expression())
while self.tokens.peek() in ["?"]:
self.tokens.expect("?")
true_expression = constant_fold(self.parse_or_expression())
self.tokens.expect(":")
false_expression = constant_fold(self.parse_or_expression())
expression = OR(AND(expression, true_expression), false_expression)
return expression
def parse_or_expression(self):
expression = self.parse_and_expression()
while self.tokens.peek() in ["||"]:
self.tokens.expect("||")
expression = OR(expression, self.parse_and_expression())
return expression
def parse_and_expression(self):
expression = self.parse_binary_expression(["|"])
while self.tokens.peek() in ["&&"]:
self.tokens.expect("&&")
expression = AND(expression, self.parse_binary_expression(["|"]))
return expression
def parse_binary_expression(self, operators):
operator_precedence = {
"|": ["^"],
"^": ["&"],
"&": ["==", "!="],
"==": ["<", ">", "<=", ">="],
"<": ["<<", ">>"],
"<<": ["+", "-"],
"+": ["*", "/", "%"],
}
if operators[0] not in operator_precedence:
expression = self.parse_unary_expression()
while self.tokens.peek() in operators:
expression = Binary(
self.tokens.get(),
expression,
self.parse_unary_expression(),
self.allocator
)
return expression
else:
next_operators = operator_precedence[operators[0]]
expression = self.parse_binary_expression(next_operators)
while self.tokens.peek() in operators:
expression = Binary(
self.tokens.get(),
expression,
self.parse_binary_expression(next_operators),
self.allocator
)
return expression
def parse_unary_expression(self):
if self.tokens.peek() == "!":
operator = self.tokens.get()
expression = self.parse_paren_expression()
return Binary("==", expression, Constant(0), self.allocator)
elif self.tokens.peek() == "-":
operator = self.tokens.get()
expression = self.parse_paren_expression()
return Binary("-", Constant(0), expression, self.allocator)
elif self.tokens.peek() == "~":
operator = self.tokens.get()
expression = self.parse_paren_expression()
return Unary("~", expression)
else:
return self.parse_paren_expression()
def parse_paren_expression(self):
if self.tokens.peek() == "(":
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
else:
expression = self.parse_number_or_variable()
return expression
def parse_number_or_variable(self):
firstToken = self.tokens.peek()
if firstToken == "true" or firstToken == "false":
return self.parseBoolean()
elif firstToken[0].isalpha():
name = self.tokens.get()
if self.tokens.peek() == "(":
return self.parse_function_call(name)
else:
return self.parse_variable(name)
else:
return self.parse_number()
def parse_input(self, name):
input_name = name.replace("input_", "")
self.tokens.expect("(")
self.tokens.expect(")")
return Input(input_name)
def parse_ready(self, name):
input_name = name.replace("ready_", "")
self.tokens.expect("(")
self.tokens.expect(")")
return Ready(input_name)
def parse_output(self, name):
output_name = name.replace("output_", "")
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
return Output(output_name, expression)
def parse_function_call(self, name):
if name.startswith("input_"):
return self.parse_input(name)
if name.startswith("ready_"):
return self.parse_ready(name)
if name.startswith("output_"):
return self.parse_output(name)
function_call = FunctionCall()
function_call.arguments = []
self.tokens.expect("(")
while self.tokens.peek() != ")":
function_call.arguments.append(self.parse_expression())
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
self.tokens.expect(")")
if name not in self.scope:
self.tokens.error("Unknown function: %s"%name)
function_call.function = self.scope[name]
function_call.type_ = function_call.function.type_
required_arguments = len(function_call.function.arguments)
actual_arguments = len(function_call.arguments)
if required_arguments != actual_arguments:
self.tokens.error("Function %s takes %s arguments %s given."%(
name,
len(function_call.function.arguments),
len(function_call.arguments)
))
required_arguments = function_call.function.arguments
actual_arguments = function_call.arguments
for required, actual in zip(required_arguments, actual_arguments):
if required.type_ != actual.type_:
self.tokens.error("Type mismatch expected type : %s got: %s."%(
required.type_,
actual.type_
))
return function_call
def parse_number(self):
token = self.tokens.get()
if token.startswith("'"):
try:
value = ord(eval(token))
except SyntaxError:
self.tokens.error("%s is not a character literal"%token)
else:
try:
value = int(eval(token))
except SyntaxError:
self.tokens.error("%s is not an integer literal"%token)
return Constant(value)
def parseBoolean(self):
token = self.tokens.get()
if token == "true":
return Boolean(True)
elif token == "false":
return Boolean(False)
else:
raise Exception
def parse_variable(self, name):
if name not in self.scope:
self.tokens.error("Unknown variable: %s"%name)
instance = self.scope[name]
return self.parse_variable_array_struct(instance)
def parse_variable_array_struct(self, instance):
if instance.type_ in ["int", "short", "long", "char"]:
return Variable(instance, self.allocator)
elif instance.type_.endswith("[]"):
if self.tokens.peek() == "[":
self.tokens.expect("[")
index_expression = self.parse_expression()
self.tokens.expect("]")
if index_expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"array indices must be an integer like expression"
)
return ArrayIndex(instance, index_expression, self.allocator)
else:
return Array(instance, self.allocator)
elif instance.type_ == "struct":
self.tokens.expect(".")
member = self.tokens.get()
instance = instance.members[member]
return self.parse_variable_array_struct(instance)
class Parser:
"""Turn the C input file into a tree of expressions and statements."""
def __init__(self, input_file, reuse):
self.scope = {}
self.function = None
self.loop = None
self.tokens = Tokens(input_file)
self.allocator = Allocator(reuse)
self.structs = []
def parse_process(self):
process = Process()
process.allocator = self.allocator
process.inputs = []
process.outputs = []
process.functions = []
while not self.tokens.end():
if self.tokens.peek() == "struct":
self.parse_define_struct()
elif self.tokens.peek() == "typedef":
self.parse_typedef_struct()
else:
process.functions.append(self.parse_function())
process.main = self.main
return process
def parse_function(self):
function = Function()
function.allocator = self.allocator
stored_scope = self.scope
type_ = self.tokens.get()
name = self.tokens.get()
#check if it is a global declaration
if self.tokens.peek() != "(":
if type_ not in ["int", "short", "long", "char"] + self.structs:
self.tokens.error("unknown type")
return self.parse_global_declaration(type_, name)
#otherwise continue parsing a function
self.tokens.expect("(")
function.name = name
function.type_ = type_
function.return_address = self.allocator.new(function.name+" return address")
if type_ not in ["int", "short", "long", "char", "void"]:
self.tokens.error("unknown type")
if type_ != "void":
function.return_value = self.allocator.new(function.name+" return value")
function.arguments = []
while self.tokens.peek() != ")":
type_ = self.tokens.get()
if type_ not in ["int", "short", "long", "char"]:
self.tokens.error("unknown type")
argument = self.tokens.get()
if self.tokens.peek() == "[":
self.tokens.expect("[")
self.tokens.expect("]")
type_+="[]"
function.arguments.append(Argument(argument, type_, self))
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
self.tokens.expect(")")
self.function = function
function.statement = self.parse_statement()
if type_ != "void" and not hasattr(function, "return_statement"):
self.tokens.error("Function must have a return statement")
self.function = None
self.scope = stored_scope
self.scope[function.name] = function
#main thread is last function
self.main = function
return function
def parse_break(self):
break_ = Break()
break_.loop = self.loop
self.tokens.expect("break")
self.tokens.expect(";")
return break_
def parse_continue(self):
continue_ = Continue()
continue_.loop = self.loop
self.tokens.expect("continue")
self.tokens.expect(";")
return continue_
def parse_return(self):
return_ = Return()
return_.function = self.function
self.function.return_statement = return_
self.tokens.expect("return")
if hasattr(self.function, "return_value"):
return_.expression = self.parse_expression()
self.tokens.expect(";")
return return_
def parse_assert(self):
assert_ = Assert()
assert_.allocator = self.allocator
self.tokens.expect("assert")
self.tokens.expect("(")
assert_.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
assert_.line = self.tokens.lineno
assert_.filename = self.tokens.filename
return assert_
def parse_report(self):
report_ = Report()
report_.allocator = self.allocator
self.tokens.expect("report")
self.tokens.expect("(")
report_.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
report_.line = self.tokens.lineno
report_.filename = self.tokens.filename
return report_
def parse_wait_clocks(self):
wait_clocks = WaitClocks()
wait_clocks.allocator = self.allocator
self.tokens.expect("wait_clocks")
self.tokens.expect("(")
wait_clocks.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
wait_clocks.line = self.tokens.lineno
return wait_clocks
def parse_statement(self):
if self.tokens.peek() in ["int", "short", "long", "char"] + self.structs:
return self.parse_compound_declaration()
elif self.tokens.peek() == "struct":
return self.parse_struct_declaration()
elif self.tokens.peek() == "if":
return self.parse_if()
elif self.tokens.peek() == "while":
return self.parse_while()
elif self.tokens.peek() == "for":
return self.parse_for()
elif self.tokens.peek() == "return":
return self.parse_return()
elif self.tokens.peek() == "break":
return self.parse_break()
elif self.tokens.peek() == "continue":
return self.parse_continue()
elif self.tokens.peek() == "{":
return self.parse_block()
elif self.tokens.peek() == "assert":
return self.parse_assert()
elif self.tokens.peek() == "report":
return self.parse_report()
elif self.tokens.peek() == "switch":
return self.parse_switch()
elif self.tokens.peek() == "case":
return self.parse_case()
elif self.tokens.peek() == "default":
return self.parse_default()
elif self.tokens.peek() == "wait_clocks":
return self.parse_wait_clocks()
else:
expression = self.parse_discard()
self.tokens.expect(";")
return expression
def parse_discard(self):
return DiscardExpression(self.parse_expression(), self.allocator)
def parse_assignment(self):
assignment_operators = [
"=", "+=", "-=", "*=", "/=", "%=", "&=", "|=", "<<=", ">>=",
"++", "--"
]
lvalue = self.parse_ternary_expression()
if self.tokens.peek() in assignment_operators:
if not hasattr(lvalue, "declaration"):
self.tokens.error(
"left hand operand of assignment is not modifiable"
)
operator = self.tokens.get()
if operator == "=":
expression = self.parse_ternary_expression()
elif operator in ["++", "--"]:
expression = Binary(
operator[:-1],
lvalue,
Constant(1),
self.allocator
)
else:
expression = Binary(
operator[:-1],
lvalue,
self.parse_ternary_expression(),
self.allocator
)
if lvalue.type_ != expression.type_:
self.tokens.error(
"type mismatch in assignment"
)
return Assignment(lvalue, expression, self.allocator)
else:
return lvalue
def parse_if(self):
if_ = If()
if_.allocator = self.allocator
self.tokens.expect("if")
self.tokens.expect("(")
if_.expression = self.parse_expression()
if if_.expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"if statement conditional must be an integer like expression"
)
self.tokens.expect(")")
if_.true_statement = self.parse_statement()
if self.tokens.peek() == "else":
self.tokens.expect("else")
if_.false_statement = self.parse_statement()
else:
if_.false_statement = None
return if_
def parse_switch(self):
switch = Switch()
switch.cases = {}
self.tokens.expect("switch")
self.tokens.expect("(")
expression = self.parse_expression()
if expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"switch statement expression must be an integer like expression"
)
self.tokens.expect(")")
stored_loop = self.loop
self.loop = switch
statement = self.parse_statement()
self.loop = stored_loop
switch.expression = expression
switch.allocator = self.allocator
switch.statement = statement
return switch
def parse_case(self):
self.tokens.expect("case")
expression = self.parse_expression()
if expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"case expression must be an integer like expression"
)
self.tokens.expect(":")
try:
expression = value(expression)
case = Case()
self.loop.cases[expression] = case
except NotConstant:
self.tokens.error("case expression must be constant")
except AttributeError:
self.tokens.error(
"case statements may only be use inside a switch statment"
)
return case
def parse_default(self):
self.tokens.expect("default")
self.tokens.expect(":")
default = Default()
if not hasattr(self.loop, "cases"):
self.tokens.error(
"default statements may only be used inside a switch statment"
)
if hasattr(self.loop, "default"):
self.tokens.error(
"A switch statement may only have one default statement"
)
self.loop.default=default
return default
def parse_while(self):
loop = Loop()
self.tokens.expect("while")
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
stored_loop = self.loop
self.loop = loop
statement = self.parse_statement()
self.loop = stored_loop
if_ = If()
loop.statement = if_
break_ = Break()
break_.loop = loop
if_.allocator = self.allocator
if expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"if statement conditional must be an integer like expression"
)
if_.expression = expression
if_.false_statement = break_
if_.true_statement = statement
return loop
def parse_for(self):
for_ = For()
for_.allocator = self.allocator
self.tokens.expect("for")
self.tokens.expect("(")
if self.tokens.peek() != ";":
for_.statement1 = self.parse_discard()
self.tokens.expect(";")
if self.tokens.peek() != ";":
for_.expression = self.parse_expression()
if for_.expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"for statement conditional must be an integer like expression"
)
self.tokens.expect(";")
if self.tokens.peek() != ")":
for_.statement2 = self.parse_discard()
self.tokens.expect(")")
stored_loop = self.loop
self.loop = for_
for_.statement3 = self.parse_statement()
self.loop = stored_loop
return for_
def parse_block(self):
block = Block()
stored_scope = self.scope
self.tokens.expect("{")
block.statements = []
while self.tokens.peek() != "}":
block.statements.append(self.parse_statement())
self.tokens.expect("}")
self.scope = stored_scope
return block
def parse_struct_body(self):
self.tokens.expect("{")
members = {}
while self.tokens.peek() != "}":
type_ = self.tokens.get()
name = self.tokens.get()
members[name] = self.parse_declaration(type_, name)
self.tokens.expect(";")
self.tokens.expect("}")
return members
def parse_typedef_struct(self):
self.tokens.expect("typedef")
self.tokens.expect("struct")
declaration = StructDeclaration(self.parse_struct_body())
name = self.tokens.get()
self.tokens.expect(";")
self.scope[name] = declaration
self.structs.append(name)
def parse_define_struct(self):
self.tokens.expect("struct")
name = self.tokens.get()
declaration = StructDeclaration(self.parse_struct_body())
self.tokens.expect(";")
self.scope[name] = declaration
def parse_struct_declaration(self):
self.tokens.expect("struct")
struct_name = self.tokens.get()
name = self.tokens.get()
self.tokens.expect(";")
instance = self.scope[struct_name].instance()
self.scope[name] = instance
return instance
def parse_global_declaration(self, type_, name):
instances = []
while True:
instance = self.parse_declaration(type_, name).instance()
self.scope[name] = instance
instances.append(instance)
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
name = self.tokens.get()
self.tokens.expect(";")
return CompoundDeclaration(instances)
def parse_compound_declaration(self):
type_ = self.tokens.get()
instances = []
while True:
name = self.tokens.get()
instance = self.parse_declaration(type_, name).instance()
self.scope[name] = instance
instances.append(instance)
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
name = None
self.tokens.expect(";")
return CompoundDeclaration(instances)
def parse_declaration(self, type_, name):
#struct declaration
if type_ in self.structs:
declaration = self.scope[type_]
elif type_ in ["int", "short", "long", "char"]:
#array declaration
if self.tokens.peek() == "[":
self.tokens.expect("[")
size = self.tokens.get()
self.tokens.expect("]")
type_+="[]"
declaration = ArrayDeclaration(self.allocator, size, type_)
#simple variable declaration
else:
if self.tokens.peek() == "=":
self.tokens.expect("=")
initializer = self.parse_ternary_expression()
else:
initializer = Constant(0)
declaration = VariableDeclaration(
self.allocator,
initializer,
name,
type_
)
return declaration
def parse_expression(self):
expression = self.parse_assignment()
return expression
def parse_ternary_expression(self):
expression = constant_fold(self.parse_or_expression())
while self.tokens.peek() in ["?"]:
self.tokens.expect("?")
true_expression = constant_fold(self.parse_or_expression())
self.tokens.expect(":")
false_expression = constant_fold(self.parse_or_expression())
expression = OR(AND(expression, true_expression), false_expression)
return expression
def parse_or_expression(self):
expression = self.parse_and_expression()
while self.tokens.peek() in ["||"]:
self.tokens.expect("||")
expression = OR(expression, self.parse_and_expression())
return expression
def parse_and_expression(self):
expression = self.parse_binary_expression(["|"])
while self.tokens.peek() in ["&&"]:
self.tokens.expect("&&")
expression = AND(expression, self.parse_binary_expression(["|"]))
return expression
def parse_binary_expression(self, operators):
operator_precedence = {
"|": ["^"],
"^": ["&"],
"&": ["==", "!="],
"==": ["<", ">", "<=", ">="],
"<": ["<<", ">>"],
"<<": ["+", "-"],
"+": ["*", "/", "%"],
}
if operators[0] not in operator_precedence:
expression = self.parse_unary_expression()
while self.tokens.peek() in operators:
expression = Binary(
self.tokens.get(),
expression,
self.parse_unary_expression(),
self.allocator
)
return expression
else:
next_operators = operator_precedence[operators[0]]
expression = self.parse_binary_expression(next_operators)
while self.tokens.peek() in operators:
expression = Binary(
self.tokens.get(),
expression,
self.parse_binary_expression(next_operators),
self.allocator
)
return expression
def parse_unary_expression(self):
if self.tokens.peek() == "!":
operator = self.tokens.get()
expression = self.parse_paren_expression()
return Binary("==", expression, Constant(0), self.allocator)
elif self.tokens.peek() == "-":
operator = self.tokens.get()
expression = self.parse_paren_expression()
return Binary("-", Constant(0), expression, self.allocator)
elif self.tokens.peek() == "~":
operator = self.tokens.get()
expression = self.parse_paren_expression()
return Unary("~", expression)
else:
return self.parse_paren_expression()
def parse_paren_expression(self):
if self.tokens.peek() == "(":
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
else:
expression = self.parse_number_or_variable()
return expression
def parse_number_or_variable(self):
if self.tokens.peek()[0].isalpha():
name = self.tokens.get()
if self.tokens.peek() == "(":
return self.parse_function_call(name)
else:
return self.parse_variable(name)
else:
return self.parse_number()
def parse_input(self, name):
input_name = name.replace("input_", "")
self.tokens.expect("(")
self.tokens.expect(")")
return Input(input_name)
def parse_ready(self, name):
input_name = name.replace("ready_", "")
self.tokens.expect("(")
self.tokens.expect(")")
return Ready(input_name)
def parse_output(self, name):
output_name = name.replace("output_", "")
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
return Output(output_name, expression)
def parse_function_call(self, name):
if name.startswith("input_"):
return self.parse_input(name)
if name.startswith("ready_"):
return self.parse_ready(name)
if name.startswith("output_"):
return self.parse_output(name)
function_call = FunctionCall()
function_call.arguments = []
self.tokens.expect("(")
while self.tokens.peek() != ")":
function_call.arguments.append(self.parse_expression())
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
self.tokens.expect(")")
if name not in self.scope:
self.tokens.error("Unknown function: %s"%name)
function_call.function = self.scope[name]
function_call.type_ = function_call.function.type_
required_arguments = len(function_call.function.arguments)
actual_arguments = len(function_call.arguments)
if required_arguments != actual_arguments:
self.tokens.error("Function %s takes %s arguments %s given."%(
name,
len(function_call.function.arguments),
len(function_call.arguments)
))
required_arguments = function_call.function.arguments
actual_arguments = function_call.arguments
for required, actual in zip(required_arguments, actual_arguments):
if required.type_ != actual.type_:
self.tokens.error("Type mismatch expected type : %s got: %s."%(
required.type_,
actual.type_
))
return function_call
def parse_number(self):
token = self.tokens.get()
if token.startswith("'"):
try:
value = ord(eval(token))
except SyntaxError:
self.tokens.error("%s is not a character literal"%token)
else:
try:
value = int(eval(token))
except SyntaxError:
self.tokens.error("%s is not an integer literal"%token)
return Constant(value)
def parse_variable(self, name):
if name not in self.scope:
self.tokens.error("Unknown variable: %s"%name)
instance = self.scope[name]
return self.parse_variable_array_struct(instance)
def parse_variable_array_struct(self, instance):
if instance.type_ in ["int", "short", "long", "char"]:
return Variable(instance, self.allocator)
elif instance.type_.endswith("[]"):
if self.tokens.peek() == "[":
self.tokens.expect("[")
index_expression = self.parse_expression()
self.tokens.expect("]")
if index_expression.type_ not in ["int", "short", "long", "char"]:
self.tokens.error(
"array indices must be an integer like expression"
)
return ArrayIndex(instance, index_expression, self.allocator)
else:
return Array(instance, self.allocator)
elif instance.type_ == "struct":
self.tokens.expect(".")
member = self.tokens.get()
instance = instance.members[member]
return self.parse_variable_array_struct(instance)
class Parser:
"""Turn the C input file into a tree of expressions and statements."""
def __init__(self, input_file, reuse, initialize_memory):
self.scope = {}
self.function = None
self.loop = None
self.tokens = Tokens(input_file)
self.allocator = Allocator(reuse)
self.structs = []
self.initialize_memory = initialize_memory
def parse_process(self):
process = Process()
process.allocator = self.allocator
process.inputs = []
process.outputs = []
process.functions = []
while not self.tokens.end():
if self.tokens.peek() == "struct":
self.parse_define_struct()
elif self.tokens.peek() == "typedef":
self.parse_typedef_struct()
else:
process.functions.append(self.parse_function())
process.main = self.main
return process
def parse_type_specifier(self):
type_specifiers = []
while self.tokens.peek() in types + self.structs + storage_specifiers:
type_specifiers.append(self.tokens.get())
signed = True
if "unsigned" in type_specifiers:
signed = False
if "signed" in type_specifiers:
self.tokens.error("Cannot be signed and unsigned")
size = 2
if "long" in type_specifiers:
if "short" in type_specifiers:
self.tokens.error("Cannot be long and short")
size = 4
type_ = "int"
for i in type_specifiers:
if i in self.structs:
type_ = i
size = 2
signed = False
if "float" in type_specifiers:
if "short" in type_specifiers:
self.tokens.error("Float cannot be short")
if "long" in type_specifiers:
self.tokens.error("Float cannot be long (but double can)")
if "unsigned" in type_specifiers:
self.tokens.error("Float cannot be unsigned")
type_ = "float"
size = 4
signed = True
const = False
if "const" in type_specifiers:
const = True
if "void" in type_specifiers:
type_ = "void"
size = 2
signed = False
return type_, size, signed, const
def parse_argument(self):
type_, size, signed, const = self.parse_type_specifier()
if type_ in ["void"]:
self.tokens.error("argument cannot be void")
else:
argument = self.tokens.get()
if type_ in self.structs:
declaration = self.scope[type_]
else:
if self.tokens.peek() == "[":
self.tokens.expect("[")
self.tokens.expect("]")
declaration = ArrayDeclaration(
self.allocator,
2,
type_+"[]",
type_,
size,
signed,
None,
self.initialize_memory)
else:
declaration = VariableDeclaration(
self.allocator,
None,
argument,
type_,
size,
signed,
const)
instance = declaration.instance()
self.scope[argument] = instance
return instance.reference()
def parse_function(self):
function = Function()
function.allocator = self.allocator
stored_scope = copy(self.scope)
type_, size, signed, const = self.parse_type_specifier()
name = self.tokens.get()
#check if it is a global declaration
if self.tokens.peek() != "(":
return self.parse_global_declaration(type_, size, signed, const, name)
#otherwise continue parsing a function
self.tokens.expect("(")
function.name = name
function.type_ = type_
function.size = size
function.signed = signed
function.return_address = self.allocator.new(2,
function.name+" return address")
if type_ != "void":
if type_ in self.structs:
declaration = self.scope[type_]
else:
if self.tokens.peek() == "[":
self.tokens.error(
"Functions cannot return arrays")
else:
declaration = VariableDeclaration(
self.allocator,
None,
function.name+" return value",
type_,
size,
signed,
const)
function.return_value = declaration.instance().reference()
function.arguments = []
while self.tokens.peek() != ")":
function.arguments.append(self.parse_argument())
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
self.tokens.expect(")")
self.function = function
function.statement = self.parse_statement()
if type_ != "void" and not hasattr(function, "return_statement"):
self.tokens.error("Function must have a return statement")
self.function = None
self.scope = stored_scope
self.scope[function.name] = function
#main thread is last function
self.main = function
return function
def parse_break(self):
break_ = Break()
break_.loop = self.loop
self.tokens.expect("break")
self.tokens.expect(";")
return break_
def parse_continue(self):
continue_ = Continue()
continue_.loop = self.loop
self.tokens.expect("continue")
self.tokens.expect(";")
return continue_
def parse_return(self):
return_ = Return()
return_.function = self.function
return_.allocator = self.allocator
self.function.return_statement = return_
self.tokens.expect("return")
if hasattr(self.function, "return_value"):
return_.expression = self.parse_expression()
self.tokens.expect(";")
return return_
def parse_assert(self):
assert_ = Assert()
assert_.allocator = self.allocator
self.tokens.expect("assert")
self.tokens.expect("(")
assert_.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
assert_.line = self.tokens.lineno
assert_.filename = self.tokens.filename
return assert_
def parse_report(self):
report_ = Report()
report_.allocator = self.allocator
self.tokens.expect("report")
self.tokens.expect("(")
report_.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
report_.line = self.tokens.lineno
report_.filename = self.tokens.filename
return report_
def parse_wait_clocks(self):
wait_clocks = WaitClocks()
wait_clocks.allocator = self.allocator
self.tokens.expect("wait_clocks")
self.tokens.expect("(")
wait_clocks.expression = self.parse_expression()
self.tokens.expect(")")
self.tokens.expect(";")
wait_clocks.line = self.tokens.lineno
return wait_clocks
def parse_statement(self):
if self.tokens.peek() in numeric_types + self.structs + storage_specifiers:
return self.parse_compound_declaration()
elif self.tokens.peek() == "struct":
return self.parse_struct_declaration()
elif self.tokens.peek() == "if":
return self.parse_if()
elif self.tokens.peek() == "while":
return self.parse_while()
elif self.tokens.peek() == "for":
return self.parse_for()
elif self.tokens.peek() == "return":
return self.parse_return()
elif self.tokens.peek() == "break":
return self.parse_break()
elif self.tokens.peek() == "continue":
return self.parse_continue()
elif self.tokens.peek() == "{":
return self.parse_block()
elif self.tokens.peek() == "assert":
return self.parse_assert()
elif self.tokens.peek() == "report":
return self.parse_report()
elif self.tokens.peek() == "switch":
return self.parse_switch()
elif self.tokens.peek() == "case":
return self.parse_case()
elif self.tokens.peek() == "default":
return self.parse_default()
elif self.tokens.peek() == "wait_clocks":
return self.parse_wait_clocks()
else:
expression = self.parse_discard()
self.tokens.expect(";")
return expression
def parse_discard(self):
return DiscardExpression(self.parse_expression(), self.allocator)
def parse_assignment(self):
assignment_operators = [
"=", "+=", "-=", "*=", "/=", "%=", "&=", "|=", "^=", "<<=", ">>="
]
lvalue = self.parse_ternary_expression()
if self.tokens.peek() in assignment_operators:
if lvalue.const():
self.tokens.error(
"left hand operand of assignment is not modifiable")
operator = self.tokens.get()
if operator == "=":
expression = self.parse_ternary_expression()
else:
expression = self.parse_ternary_expression()
left = lvalue
left, expression = self.coerce_types(left, expression)
expression = Binary(operator[:-1], left, expression)
if expression.type_() != lvalue.type_():
if expression.type_() == "int" and lvalue.type_() == "float":
expression = IntToFloat(expression)
elif expression.type_() == "float" and lvalue.type_() == "int":
expression = FloatToInt(expression)
else:
self.tokens.error(
"type mismatch in assignment expected: %s actual: %s"%(
lvalue.type_(),
expression.type_()))
return Assignment(lvalue, expression, self.allocator)
else:
return lvalue
def parse_if(self):
if_ = If()
if_.allocator = self.allocator
self.tokens.expect("if")
self.tokens.expect("(")
if_.expression = self.parse_expression()
if if_.expression.type_() not in ["unsigned", "int", "short", "long", "char"]:
self.tokens.error(
"if statement conditional must be an integer like expression")
self.tokens.expect(")")
if_.true_statement = self.parse_statement()
if self.tokens.peek() == "else":
self.tokens.expect("else")
if_.false_statement = self.parse_statement()
else:
if_.false_statement = None
return if_
def parse_switch(self):
switch = Switch()
switch.cases = {}
self.tokens.expect("switch")
self.tokens.expect("(")
expression = self.parse_expression()
if expression.type_() not in ["unsigned", "int", "short", "long", "char"]:
self.tokens.error(
"switch statement expression must be an integer like expression")
self.tokens.expect(")")
stored_loop = self.loop
self.loop = switch
statement = self.parse_statement()
self.loop = stored_loop
switch.expression = expression
switch.allocator = self.allocator
switch.statement = statement
return switch
def parse_case(self):
self.tokens.expect("case")
expression = self.parse_expression()
if expression.type_() not in ["int"]:
self.tokens.error(
"case expression must be an integer like expression")
self.tokens.expect(":")
try:
expression = expression.value()
case = Case()
self.loop.cases[expression] = case
except NotConstant:
self.tokens.error("case expression must be constant")
except AttributeError:
self.tokens.error(
"case statements may only be use inside a switch statment")
return case
def parse_default(self):
self.tokens.expect("default")
self.tokens.expect(":")
default = Default()
if not hasattr(self.loop, "cases"):
self.tokens.error(
"default statements may only be used inside a switch statment")
if hasattr(self.loop, "default"):
self.tokens.error(
"A switch statement may only have one default statement")
self.loop.default=default
return default
def parse_while(self):
loop = Loop()
self.tokens.expect("while")
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
stored_loop = self.loop
self.loop = loop
statement = self.parse_statement()
self.loop = stored_loop
if_ = If()
loop.statement = if_
break_ = Break()
break_.loop = loop
if_.allocator = self.allocator
if expression.type_() not in ["int"]:
self.tokens.error(
"while statement conditional must be an integer like expression")
if_.expression = expression
if_.false_statement = break_
if_.true_statement = statement
return loop
def parse_for(self):
for_ = For()
for_.allocator = self.allocator
self.tokens.expect("for")
self.tokens.expect("(")
if self.tokens.peek() != ";":
for_.statement1 = self.parse_discard()
self.tokens.expect(";")
if self.tokens.peek() != ";":
for_.expression = self.parse_expression()
if for_.expression.type_() not in [
"unsigned",
"int",
"short",
"long",
"char"]:
self.tokens.error(
"For statement conditional must be an integer like expression")
self.tokens.expect(";")
if self.tokens.peek() != ")":
for_.statement2 = self.parse_discard()
self.tokens.expect(")")
stored_loop = self.loop
self.loop = for_
for_.statement3 = self.parse_statement()
self.loop = stored_loop
return for_
def parse_block(self):
block = Block()
stored_scope = copy(self.scope)
self.tokens.expect("{")
block.statements = []
while self.tokens.peek() != "}":
block.statements.append(self.parse_statement())
self.tokens.expect("}")
self.scope = stored_scope
return block
def parse_struct_body(self):
self.tokens.expect("{")
members = {}
while self.tokens.peek() != "}":
type_, size, signed, const = self.parse_type_specifier()
name = self.tokens.get()
members[name] = self.parse_declaration(
type_,
size,
signed,
const,
name)
self.tokens.expect(";")
self.tokens.expect("}")
return members
def parse_typedef_struct(self):
self.tokens.expect("typedef")
self.tokens.expect("struct")
declaration = StructDeclaration(self.parse_struct_body())
name = self.tokens.get()
self.tokens.expect(";")
self.scope[name] = declaration
self.structs.append(name)
def parse_define_struct(self):
self.tokens.expect("struct")
name = self.tokens.get()
declaration = StructDeclaration(self.parse_struct_body())
self.tokens.expect(";")
self.scope[name] = declaration
def parse_struct_declaration(self):
self.tokens.expect("struct")
struct_name = self.tokens.get()
name = self.tokens.get()
self.tokens.expect(";")
instance = self.scope[struct_name].instance()
self.scope[name] = instance
return instance
def parse_global_declaration(self, type_, size, signed, const, name):
instances = []
while True:
instance = self.parse_declaration(
type_,
size,
signed,
const,
name).instance()
self.scope[name] = instance
instances.append(instance)
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
name = self.tokens.get()
self.tokens.expect(";")
return CompoundDeclaration(instances)
def parse_compound_declaration(self):
type_, size, signed, const = self.parse_type_specifier()
instances = []
while True:
name = self.tokens.get()
instance = self.parse_declaration(
type_,
size,
signed,
const,
name).instance()
self.scope[name] = instance
instances.append(instance)
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
name = None
self.tokens.expect(";")
return CompoundDeclaration(instances)
def parse_declaration(self, type_, size, signed, const, name):
#struct declaration
if type_ in self.structs:
declaration = self.scope[type_]
elif type_ in ["int", "float"]:
#array declaration
if self.tokens.peek() == "[":
array_size = None
self.tokens.expect("[")
if self.tokens.peek() != "]":
size_expression = self.parse_ternary_expression()
if size_expression.type_() != "int":
self.tokens.error("Array size must be an integer like expression")
try:
array_size = size_expression.value()
except NotConstant:
self.tokens.error("Array size must be constant")
self.tokens.expect("]")
initializer = None
if self.tokens.peek() == "=":
self.tokens.expect("=")
initializer = self.tokens.get()
initializer = [ord(i) for i in initializer.strip('"').decode("string_escape")] + [0]
array_size = len(initializer)
if array_size is None:
self.tokens.error(
"array size must be specified if not initialized")
array_type=type_+"[]"
initialize_memory = self.initialize_memory
declaration = ArrayDeclaration(
self.allocator,
array_size,
array_type,
type_,
size,
signed,
initializer,
self.initialize_memory)
#simple variable declaration
else:
if self.tokens.peek() == "=":
self.tokens.expect("=")
initializer = self.parse_ternary_expression()
else:
initializer = Constant(0, type_, size, signed)
if type_ != initializer.type_():
if type_ == "int" and initializer.type_() == "float":
initializer = FloatToInt(initializer)
elif type_ == "float" and initializer.type_() == "int":
initializer = IntToFloat(initializer)
else:
self.tokens.error(
"type mismatch in intializer expected: %s actual: %s"%(
type_,
intitializer.type_()))
declaration = VariableDeclaration(
self.allocator,
initializer,
name,
type_,
size,
signed,
const
)
return declaration
def parse_expression(self):
expression = self.parse_assignment()
return expression
def parse_ternary_expression(self):
expression = constant_fold(self.parse_or_expression())
while self.tokens.peek() in ["?"]:
self.tokens.expect("?")
true_expression = constant_fold(self.parse_or_expression())
self.tokens.expect(":")
false_expression = constant_fold(self.parse_or_expression())
expression = OR(AND(expression, true_expression), false_expression)
return expression
def parse_or_expression(self):
expression = self.parse_and_expression()
while self.tokens.peek() in ["||"]:
self.tokens.expect("||")
expression = OR(expression, self.parse_and_expression())
return expression
def parse_and_expression(self):
expression = self.parse_binary_expression(["|"])
while self.tokens.peek() in ["&&"]:
self.tokens.expect("&&")
expression = AND(expression, self.parse_binary_expression(["|"]))
return expression
def substitute_function(self, binary_expression):
"""
For some operations are more easily implemented in sofftware.
This function substitutes a call to the builtin library function.
"""
functions = {
"False,int,int,4,/" : "long_unsigned_divide_xxxx",
"True,int,int,4,/" : "long_divide_xxxx",
"False,int,int,2,/" : "unsigned_divide_xxxx",
"True,int,int,2,/" : "divide_xxxx",
"False,int,int,4,%" : "long_unsigned_modulo_xxxx",
"True,int,int,4,%" : "long_modulo_xxxx",
"False,int,int,2,%" : "unsigned_modulo_xxxx",
"True,int,int,2,%" : "modulo_xxxx",
"True,float,float,4,==" : "float_equal_xxxx",
"True,float,float,4,!=" : "float_ne_xxxx",
"True,float,float,4,<" : "float_lt_xxxx",
"True,float,float,4,>" : "float_gt_xxxx",
"True,float,float,4,<=" : "float_le_xxxx",
"True,float,float,4,>=" : "float_ge_xxxx",
}
#select a function that matches the template.
signature = ",".join([
str(binary_expression.signed()),
binary_expression.left.type_(),
binary_expression.right.type_(),
str(binary_expression.size()),
binary_expression.operator])
#Some things can't be implemented in verilog, substitute them with a function
if signature in functions:
function = self.scope[functions[signature]]
function_call = FunctionCall(function)
function_call.arguments = [binary_expression.left, binary_expression.right]
return function_call
else:
return binary_expression
def coerce_types(self, left, right):
"""
Convert numeric types in expressions.
"""
if left.type_() != right.type_():
if left.type_() == "float" and right.type_() == "int":
return left, IntToFloat(right)
elif left.type_() == "int" and right.type_() == "float":
return IntToFloat(left), right
else:
self.tokens.error("Incompatible types : %s %s"%(
left.type_(),
right.type_()))
return left, right
def parse_binary_expression(self, operators):
operator_precedence = {
"|": ["^"],
"^": ["&"],
"&": ["==", "!="],
"==": ["<", ">", "<=", ">="],
"<": ["<<", ">>"],
"<<": ["+", "-"],
"+": ["*", "/", "%"],
}
if operators[0] not in operator_precedence:
left = self.parse_unary_expression()
while self.tokens.peek() in operators:
operator = self.tokens.get()
right = self.parse_unary_expression()
left, right = self.coerce_types(left, right)
left = Binary(operator, left, right)
left = self.substitute_function(left)
return left
else:
next_operators = operator_precedence[operators[0]]
left = self.parse_binary_expression(next_operators)
while self.tokens.peek() in operators:
operator = self.tokens.get()
right = self.parse_binary_expression(next_operators)
left, right = self.coerce_types(left, right)
left = Binary(operator, left, right)
left = self.substitute_function(left)
return left
def parse_unary_expression(self):
if self.tokens.peek() == "!":
operator = self.tokens.get()
expression = self.parse_postfix_expression()
return Binary("==", expression, Constant(0))
elif self.tokens.peek() == "-":
operator = self.tokens.get()
expression = self.parse_postfix_expression()
return Binary("-", Constant(0,
expression.type_(),
expression.size(),
expression.signed()),
expression)
elif self.tokens.peek() == "~":
operator = self.tokens.get()
expression = self.parse_postfix_expression()
return Unary("~", expression)
elif self.tokens.peek() == "sizeof":
operator = self.tokens.get()
expression = self.parse_unary_expression()
return SizeOf(expression)
else:
return self.parse_postfix_expression()
def parse_postfix_expression(self):
expression = self.parse_paren_expression()
while self.tokens.peek() in ["++", "--"]:
operator = self.tokens.get()
expression = PostIncrement(
operator[:-1],
expression,
self.allocator
)
return expression
def parse_paren_expression(self):
if self.tokens.peek() == "(":
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
else:
expression = self.parse_number_or_variable()
return expression
def parse_number_or_variable(self):
if self.tokens.peek()[0].isalpha():
name = self.tokens.get()
if self.tokens.peek() == "(":
return self.parse_function_call(name)
else:
return self.parse_variable(name)
else:
return self.parse_number()
def parse_file_read(self):
self.tokens.expect("(")
file_name = self.tokens.get()
file_name = file_name.strip('"').decode("string_escape")
self.tokens.expect(")")
return FileRead(file_name)
def parse_file_write(self):
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(",")
file_name = self.tokens.get()
file_name = file_name.strip('"').decode("string_escape")
self.tokens.expect(")")
return FileWrite(file_name, expression)
def parse_input(self, name):
input_name = name.replace("input_", "")
self.tokens.expect("(")
self.tokens.expect(")")
return Input(input_name)
def parse_ready(self, name):
input_name = name.replace("ready_", "")
self.tokens.expect("(")
self.tokens.expect(")")
return Ready(input_name)
def parse_output(self, name):
output_name = name.replace("output_", "")
self.tokens.expect("(")
expression = self.parse_expression()
self.tokens.expect(")")
return Output(output_name, expression)
def parse_function_call(self, name):
if name.startswith("input_"):
return self.parse_input(name)
if name.startswith("ready_"):
return self.parse_ready(name)
if name.startswith("output_"):
return self.parse_output(name)
if name == "file_read":
return self.parse_file_read()
if name == "file_write":
return self.parse_file_write()
if name not in self.scope:
self.tokens.error("Unknown function: %s"%name)
function = self.scope[name]
function_call = FunctionCall(function)
function_call.arguments = []
self.tokens.expect("(")
while self.tokens.peek() != ")":
function_call.arguments.append(self.parse_expression())
if self.tokens.peek() == ",":
self.tokens.expect(",")
else:
break
self.tokens.expect(")")
required_arguments = len(function_call.function.arguments)
actual_arguments = len(function_call.arguments)
if required_arguments != actual_arguments:
self.tokens.error("Function %s takes %s arguments %s given."%(
name,
len(function_call.function.arguments),
len(function_call.arguments)))
required_arguments = function_call.function.arguments
actual_arguments = function_call.arguments
corrected_arguments = []
for required, actual in zip(required_arguments, actual_arguments):
if not compatible(required, actual):
if actual.type_() == "int" and required.type_() == "float":
actual = IntToFloat(actual)
elif actual.type_() == "float" and required.type_() == "int":
actual = FloatToInt(actual)
else:
self.tokens.error(
"type mismatch in assignment expected: %s actual: %s"%(
required.type_(),
actual.type_()))
corrected_arguments.append(actual)
function_call.arguments = corrected_arguments
return function_call
def parse_number(self):
token = self.tokens.get()
type_ = "int"
size = 2
signed = True
if token.startswith("'"):
try:
token = eval(token)
value = ord(token)
except SyntaxError:
self.tokens.error("%s is not a character literal"%token)
elif token.startswith('"'):
try:
initializer = [ord(i) for i in token.strip('"').decode("string_escape")] + [0]
size = len(initializer)
initialize_memory = self.initialize_memory
declaration = ArrayDeclaration(
self.allocator,
size,
"int[]",
"int",
2,
False,
initializer,
self.initialize_memory)
return ConstArray(declaration.instance())
except SyntaxError:
self.tokens.error("%s is not a character literal"%token)
elif "." in token:
#float literal
try:
type_ = "float"
signed = True
size = 4
token = token.upper().replace("F", "")
token = token.upper().replace("L", "")
value = float(eval(token))
try:
byte_value = struct.pack(">f", value)
except OverflowError:
self.tokens.error("value too large")
except SyntaxError:
self.tokens.error("%s is not a floating point literal"%token)
else:
#integer literal
try:
if "U" in token.upper():
signed = False
if "L" in token.upper():
size = 4
token = token.upper().replace("U", "")
value = int(eval(token))
if signed:
if value > 2**((size * 8)-1) - 1:
self.tokens.error("value too large")
if value < -(2**((size * 8)-1)):
self.tokens.error("value too small")
else:
if value > 2**(size * 8) - 1:
self.tokens.error("value too large")
if value < 0:
self.tokens.error("value too small")
except SyntaxError:
self.tokens.error("%s is not an integer literal"%token)
return Constant(value, type_, size, signed)
def parse_variable(self, name):
if name not in self.scope:
self.tokens.error("Unknown variable: %s"%name)
instance = self.scope[name]
return self.parse_variable_array_struct(instance)
def parse_variable_array_struct(self, instance):
if instance.type_() in numeric_types:
if not hasattr(instance, "reference"):
self.tokens.error(
"Not an expression")
return Variable(instance)
elif instance.type_().endswith("[]"):
if self.tokens.peek() == "[":
self.tokens.expect("[")
index_expression = self.parse_expression()
self.tokens.expect("]")
if index_expression.type_() not in ["int"]:
self.tokens.error(
"Array indices must be an integer like expression")
return ArrayIndex(instance, index_expression)
else:
return Array(instance)
elif instance.type_().startswith("struct"):
if self.tokens.peek() == ".":
self.tokens.expect(".")
member = self.tokens.get()
instance = instance.members[member]
return self.parse_variable_array_struct(instance)
else:
return Struct(instance)