def name_element(tree, tag, canonicalize=False):
"""Gives elements a name= attribute as their name.
Searches for tags with the specified tag name. Takes the first identifier
under the tag and uses the text of that element as the name= atribute of
the tag.
Arguments:
tree: The parse tree to modify
tag: The name of the tag to name specified as a string"""
for tag in tree.findall(".//" + tag):
found = tag.find("tok_identifier")
if found is None:
found = tag.find("./simple_name")
name = util.name_to_str(found)
else:
name = found.text
tag.set("name", name)
tag.remove(found)
if canonicalize:
if tree.find("package_declaration") is None:
tag.set("canonical_name", tag.get("name"))
else:
tag.set("canonical_name",
util.name_to_str(tree.find("package_declaration")) +
"." + tag.get("name"))
def typecheck_other_conditions(tree):
"""Takes an abstract syntax tree which has Environments associated with it
and typechecks it. Raises JoosSyntaxException if the tree does not
typecheck."""
# A constructor in a class other than java.lang.Object implicitly calls the
# zero-argument constructor of its superclass. Check that this
# zero-argument constructor exists.
#
# Check that the name of a constructor is the same as the name of its
# enclosing class.
for ctor in tree.findall(".//constructor_declaration"):
clazz = ctor.env.findclass(ctor.get("name"))
superclazz = clazz.superclass
error_if(not superclazz.env.find_constructor(tuple([])),
"No zero-argument constructor")
for lhs in tree.findall(".//assignment/left_hand_side"):
if lhs.find("./name") is None:
continue
type_name = name_to_str(lhs.find("./name"))
type_decl = lhs.env.get_declaration_site_for_variable_name(type_name, lhs.find("./name"))
error_if("final" in modifiers(type_decl),
"Final field on LHS")
#Check that no objects of abstract classes are created.
for expr in tree.findall(".//class_instance_creation_expression"):
expr_type = name_to_str(expr.find("./name"))
instantiated_class = tree.env.findclass(expr_type)
error_if("abstract" in modifiers(instantiated_class) or
instantiated_class.tag == "interface",
"Cannot instantiate abstract classes.")
class_name = instantiated_class.get("canonical_name")
ctor_decl = expr.env.get_declaration_site_for_constructor_name(
class_name,
argument_list(expr))
error_if(expr.env.find_package_name() !=
ctor_decl.env.find_package_name()
and "protected" in modifiers(ctor_decl),
"Invocation of Protected Constructor.")
# Check that the implicit this variable is not accessed in a static method
# or in the initializer of a static field.
for smethod in \
[x for x in tree.findall(".//method") if "static" in modifiers(x)]:
error_if(smethod.find(".//tok_this") is not None,
"Cannot acces this in static method.")
for field in \
[x for x in tree.findall(".//field") if "static" in modifiers(x)]:
error_if(field.find(".//tok_this") is not None,
"Cannot acces this in static field.")
#if_then_stmts = tree.find(".//if_then_statement/expression//assignment")
#error_if(if_then_stmts is not None,
#"No assignment in if_then expressions")
while_stmts = tree.find(".//while_statement/expression//assignment")
def initialize_class_or_interface_environment(self, tree):
self.fields["this"] = self.tree
self.add_field_declarations_to_environment(tree)
self.add_constructor_declarations_to_environments(tree)
self.add_method_declarations_to_environment(tree)
implemented_interface_names = [self.findclass(name_to_str(x)) for x in
tree.findall(".//implements/name")]
extended_interface_names = [self.findclass(name_to_str(x)) for x in
tree.findall(".//extends_interfaces/name")]
self.tree.interfaces = implemented_interface_names + \
extended_interface_names
def add_import_star_statements(self, imported, tree, trees):
star_import_names = [name_to_str(x) for x in
tree.findall(".//star_import/name")]
star_import_names += ["java.lang"]
for fullname in star_import_names:
if fullname not in imported:
imported += [fullname]
tmp = find_all_in_package(fullname, trees)
used = [name_to_str(x) for x in
tree.findall(".//name")] + ["Object"]
for key in tmp:
if key not in self.classes_single: # and key in used:
error_if(key in self.classes_star and key in used,
"Ambiguous class %s" % key)
self.classes_star[key] = tmp[key]
def type_tag_of_subtree(subtree, if_array_then_contents=False):
if isarray(collect_token_text(subtree)):
if if_array_then_contents:
subtree = subtree[0]
if subtree.tag == "primitive_type":
return {"short": -1, "int": -2, "char": -3, "byte": -4, "boolean": -5}[collect_token_text(subtree)]
return subtree.env.findclass(name_to_str(subtree)).type_tag
def check(files):
try:
trees = build_envs(files)
#All statements must be reachable. Details of the exact definition of
#reachability are specified in Section 14.20 of the Java Language
#Specification.
for tree in trees:
for block in (tree.findall(".//method/block") +
tree.findall(".//constructor_body")):
check_reachability(block)
for method in tree.findall(".//method"):
if method.find(".//tok_void") is None:
returns = always_returns(method.find("block"))
error_if(not returns,
"Doesn't always return from nonvoid method")
#Every local variable must have an initializer, and the variable must
#not occur in its own initializer.
for tree in trees:
for lvar in tree.findall(".//local_variable_declaration"):
name = lvar.find(".//variable/tok_identifier").text
error_if(lvar.find(".//expression") is None,
"Every local variable must have an initializer")
for ident in lvar.findall(".//expression//name"):
error_if(name == name_to_str(ident),
"Self cannot appear in local variable initializer.")
return 0
except JoosSyntaxException, e:
if not Testing.testing:
print e.msg
return 42
def method_invocation(element):
if element[0].tag == "name":
name = name_to_str(element.find("name"))
to_file(element)
declaration_site = element.env.get_declaration_site_for_method_name(
name,
argument_list(element))
element.attrib["type"] = element.env.get_type_for_declaration_site(
declaration_site)
element.declaration = declaration_site
elif element[0].tag == "primary":
primary_type = element[0].attrib["type"]
error_if(is_primitive(primary_type),
"Cannot invoke method on primitive " + primary_type)
declaration_site = element.env.get_declaration_site_for_class_name(
primary_type)
identifier = element.find("tok_identifier").text
method_declaration = \
declaration_site.env.get_declaration_site_for_method_name(
identifier,
argument_list(element))
element.attrib["type"] = \
method_declaration.env.get_type_for_declaration_site(
method_declaration)
element.declaration = method_declaration
else:
assert False
def check_field_initializers(tree):
#Check the rules specified in Section 8.3.2.3 of the Java Language
#Specification regarding forward references. The initializer of a
#non-static field must not use (i.e. read) by simple name (i.e. without an
#explicit this) itself or a non-static field declared later in the same
#class.
#The declaration of a member needs to appear before it is used only if the
#member is an instance (respectively static) field of a class or interface
#C and all of the following conditions hold:
#The usage occurs in an instance (respectively static) variable initializer
#of C or in an instance (respectively static) initializer of C.
#The usage is not on the left hand side of an assignment.
#C is the innermost class or interface enclosing the usage.
fields = tree.findall(".//field")
for x in xrange(len(fields)):
field = fields[x]
forward_references = fields[x:]
forward_reference_names = []
for forward_reference in forward_references:
forward_reference_names.append(
name_to_str(forward_reference.find(".//variable")))
potential_elements = set()
expression_element = field.find("expression")
if expression_element is not None:
for child in expression_element.findall(".//name"):
child_name = name_to_str(child).split(".")[0]
if child_name in forward_reference_names:
potential_elements.add(child)
valid_references = field.findall(".//left_hand_side/name")
valid_references += \
field.findall(".//class_instance_creation_expression/name")
for child in valid_references:
for subchild in child.getiterator():
potential_elements.discard(subchild)
error_if(len(potential_elements),
"Forward reference not allowed in initializer.")
if static_declaration(field):
for name in field.findall(".//name"):
if hasattr(child, "declaration") and isvariable(child.declaration):
field.env.get_declaration_site_for_variable_name(name_to_str(name),name)
def add_single_type_import_statements(self, pkg, this_clazz, tree, trees):
import_names = [name_to_str(x) for x in tree.findall(".//import/name")]
for fullname in import_names:
name = fullname[fullname.rfind(".") + 1:]
error_if(name in self.classes_this and
not fullname == pkg + "." + this_clazz.get("name"),
"Single-type imports clash with class defined in file.")
error_if(name in self.classes_single and
not self.__findclass(fullname, trees) ==
self.classes_single[name],
"Two single-type import decls clash with each other.")
self.classes_single[name] = self.__findclass(fullname, trees)
def check_hierarchy(tree):
clazz = tree.find(".//class")
if not clazz:
clazz = tree.find(".//interface")
ifaces = [clazz.env.findclass(name_to_str(x)) for x in
clazz.findall(".//implements/name")]
for i in range(0, len(ifaces)):
error_if(ifaces[i] in ifaces[i + 1:],
"Mention an interface more than once")
if clazz.tag == "interface":
check_cyclic(clazz, [])
def array_access(element):
if element[0].tag == "name":
name = name_to_str(element[0])
decl_site = element.env.get_declaration_site_for_variable_name(name,
element[0])
type_name = element.env.get_type_for_declaration_site(decl_site)
element.declaration = decl_site
else:
type_name = element[0].attrib["type"]
error_if(not isarray(type_name), "Array access on non-array type.")
element.attrib["type"] = type_name[:-2]
index_expression_type = element[-2].attrib["type"]
error_if(not is_integral_primitive(index_expression_type),
"Cannot index into array with non-integral expression.")
def __superclass(self, clazz):
"""For a given 'class' subtree and environment, returns the 'class'
referring to the class's supertype. Used to assign the superclass of a
tree."""
if clazz.find(".//extends//name") is not None:
c_name = name_to_str(clazz.find(".//extends//name"))
if clazz.env.findclass(c_name) is not None:
error_if(clazz.env.findclass(c_name).tag != "class",
"Must not extend an interface class.")
error_if(clazz == clazz.env.findclass(c_name),
"Class cannot extend itself")
error_if("final" in modifiers(clazz.env.findclass(c_name)),
"Cannot extend a final class.")
return clazz.env.findclass(c_name)
else:
error_if(True, "Must extend an existing class.")
return clazz.env.findclass("java.lang.Object")
def initialize_compilation_unit_environment(self, name_to_class, tree,
trees):
pkg = ""
if tree.find(".//package//name"):
pkg = name_to_str(tree.find(".//package//name"))
self.package_name = pkg
this_clazz = find_type_decl(tree)
self.classes_this[this_clazz.get("name")] = this_clazz
self.classes_this["this"] = this_clazz
self.classes_package = find_all_in_package(pkg, trees)
self.add_single_type_import_statements(pkg, this_clazz, tree, trees)
imported = []
self.add_import_star_statements(imported, tree, trees)
add_dict(find_all_in_package(pkg, trees), self.classes_package)
add_dict(name_to_class, self.classes_fully_qualified)
def cast_expression(element):
if element[1].tag == "name":
expression_being_cast = element.find("unary_expression_not_plus_minus")
cast_type = element.env.canonicalize_name(name_to_str(element[1]))
if element.find("dims"):
cast_type += "[]"
elif element[1].tag == "expression":
# Expression case
cast_type = element[1].attrib["type"]
expression_being_cast = element[-1]
else:
# Primitive cast case
cast_type = collect_token_text(element[1])
if element[2].tag == "dims":
cast_type += "[]"
expression_being_cast = element[-1]
error_if(not element.env.can_be_cast(expression_being_cast.attrib["type"],
cast_type), "TODO(thurn): This is an error.")
element.attrib["type"] = cast_type
def result(element):
if len(element) == 1:
if element[0].tag == "name" or element[0].tag == "qualified_name":
name_string = name_to_str(element[0])
declaration_site = \
element.env.get_declaration_site_for_variable_name(
name_string,
element[0])
type_string = \
declaration_site.env.get_type_for_declaration_site(
declaration_site)
element.attrib["type"] = type_string
element[0].attrib["type"] = type_string
elif element[0].tag == "tok_this":
element.attrib["type"] = element.env.canonicalize_name("this")
element[0].declaration = element.env.findclass("this")
else:
element.attrib["type"] = element[0].attrib["type"]
else:
function(element)
def interface_methods(clazz):
"""Returns all methods declared in interfaces the class implements."""
methods = []
if clazz.tag == "class":
iface_supers = clazz.interfaces
else:
iface_supers = [clazz]
found_ifaces = []
while iface_supers:
cur_clazz = iface_supers[0]
error_if(cur_clazz is None, "Class not defined.")
iface_supers = iface_supers[1:]
if cur_clazz not in found_ifaces:
methods += cur_clazz.findall(".//abstract_method")
tmp = [cur_clazz.env.findclass(name_to_str(x)) for x in
cur_clazz.findall(".//extends_interfaces/name")]
iface_supers += tmp
found_ifaces += [cur_clazz]
return methods
def find_all_in_package(packagename, trees):
"""Returns all classses in packagename."""
global find_all_in_package_cache
if packagename in find_all_in_package_cache:
return find_all_in_package_cache[packagename]
retn = {}
prefix = False
for tree in trees:
clazz = find_type_decl(tree)
if clazz is None:
continue
if tree.find(".//package/name") is not None:
package_name = name_to_str(tree.find(".//package/name"))
if package_name == packagename:
retn[clazz.get("name")] = clazz
elif (packagename == package_name[:len(packagename)]
and package_name[len(packagename)] == "."):
prefix = True
elif packagename == "":
retn[clazz.get("name")] = clazz
error_if(not prefix and len(retn.keys()) == 0,
"No class in %s" % packagename)
find_all_in_package_cache[packagename] = retn
return retn
def __findclass(self, fullname, trees):
"""Returns the 'class' object for the class.
Fullname: fully qualified name of a class
pkg: package to look in
trees: set of ASTs to look in
"""
name = fullname[fullname.rfind(".") + 1:]
pkg = fullname[:fullname.rfind(".")]
for tree in trees:
clazz = find_type_decl(tree)
if clazz is None:
continue
if name == clazz.get("name"):
package_name = ""
if tree.find(".//package/name") is not None:
package_name = name_to_str(tree.find(".//package/name"))
if ((package_name == "" and fullname == name) or
(package_name == "java.lang" and fullname == name) or
pkg == package_name or
fullname[:len(fullname) - len(name) - 1] == package_name):
return clazz
error_if(True, "No class to import / Class Not Found.")
def class_qualified_name_for_field(field):
class_name = field.env.findclass("this").get("name")
field_name = name_to_str(field.find(".//variable"))
return class_name + "." + field_name
def check_types(tree):
"""Checks for type and other errors in tree."""
toks = tree.findall(".//package//tok_identifier")
name = ""
for ident in range(0, len(toks)):
name += toks[ident].text
error_if(name in tree.env.classes_fully_qualified and
name.find(".") != -1,
"Package prefix conflicts with class name.")
if ident < len(toks) - 1:
name += "."
clazz = find_type_decl(tree)
if clazz is None:
return
for _ in all_with_modifier(clazz, "method", "abstract"):
error_if("abstract" not in modifiers(clazz),
"Abstract methods must be in abstract classes.")
for it in clazz.findall(".//implements/name") + clazz.findall(
".//extends/name") + clazz.findall(
".//extends_interfaces/name"):
name = name_to_str(it)
error_if(clazz.env.findclass(name) is None,
"No class %s defined." % name)
for type_use in clazz.findall(".//type") + clazz.findall(
".//class_instance_creation_expression/name"):
name = ""
toks = type_use.findall(".//tok_identifier")
for ident in range(0, len(toks)):
name += toks[ident].text
if ident < len(toks) - 1:
error_if(tree.env.findclass(name),
"Prefixes of fully qualified type resolves to type.")
name += "."
if type_use.find(".//name") is not None:
clazz_name = name_to_str(type_use.find(".//name"))
error_if(not clazz.env.findclass(clazz_name),
"Type " + clazz_name + " doesn't exist.")
for i_type in clazz.findall(".//implements/name"):
i_name = name_to_str(i_type)
error_if(clazz.env.findclass(i_name) is not None and
clazz.env.findclass(i_name).tag != "interface",
"Must implement an interface class.")
for c_type in clazz.findall(".//extends_interfaces/name"):
c_name = name_to_str(c_type)
error_if(clazz.env.findclass(c_name).tag != "interface",
"Must extend an interface class.")
error_if(clazz == clazz.env.findclass(c_name),
"Class cannot extend itself")
for inf in tree.findall(".//implements/name"):
name = name_to_str(inf)
error_if(clazz.env.findclass(name).tag != "interface",
"%s is not an interface." % name)
for clz in tree.findall(".//class_type/name") + tree.findall(
".//implements/name"):
name = name_to_str(clz)
error_if((tree.env.findclass(name) is None) or
(tree.env.findclass(
name).tag == "class"),
"%s is not an interface." % name)
def class_instance_creation(element):
name = name_to_str(element.find("name"))
element.attrib["type"] = element.env.canonicalize_name(name)
resolve_constructor_name(element)
def resolve_constructor_name(element):
return element.env.get_declaration_site_for_constructor_name(
name_to_str(element.find("name")),
argument_list(element))
def check_cyclic(iface, pifaces):
error_if(iface in pifaces, "Cycle in interface")
for eiface in [iface.env.findclass(name_to_str(x)) for x in
iface.findall(".//extends_interfaces/name")]:
check_cyclic(eiface, pifaces + [iface])
def instanceof_assembly(value_slot, destination_slot, type_subtree, debug_string, isarray=False):
rhs_type = type_subtree.env.findclass(name_to_str(type_subtree))
label_no = new_label_no()
zero_case = "EQUALITY_ZERO_" + str(label_no)
one_case = "EQUALITY_ONE_" + str(label_no)
final = "EQUALITY_FINAL_" + str(label_no)
# TODO: arrays
if rhs_type is None or isarray:
return """
;instanceof_array {dbg}
mov eax, {lhs}
sub eax, 0
jz .{false_case}
mov ebx, [eax]
mov ebx, [ebx]
sub ebx, 0
jz .{array_case}
jmp .{false_case}
.{array_case}:
mov eax, [eax + 4]
sub eax, {type_tag_rhs}
jnz .{false_case}
mov {result}, {true}
jmp .{final}
.{false_case}:
mov {result}, {false}
.{final}:
;end instanceof
""".format(
lhs=stack_slot_to_operand(value_slot),
dbg=debug_string,
array_case=zero_case,
false_case=one_case,
type_tag_rhs=type_tag_of_subtree(type_subtree, True),
result=stack_slot_to_operand(destination_slot),
true=true,
final=final,
false=false,
)
else:
return """
; instanceof {dbg}
mov eax, {lhs}
sub eax, 0
jz .{zero_case} ; check for null
mov eax, [eax] ; deference to object
mov eax, [eax] ; dereference to vable
mov ecx, {number_of_classes}
imul ecx
add eax, {type_tag}
mov eax, [__instanceof_table + eax]
sub eax, -1
jz .{one_case}
.{zero_case}:
mov {result}, {false}
jmp .{final_location}
.{one_case}:
mov {result}, {true}
.{final_location}:
""".format(
dbg=debug_string,
type_tag=str(rhs_type.type_tag * 4),
lhs=stack_slot_to_operand(value_slot),
zero_case=zero_case,
one_case=one_case,
result=stack_slot_to_operand(destination_slot),
true=true,
false=false,
final_location=final,
number_of_classes=str(len(method_list.class_list) * 4),
)
def name(subtree, args=None):
# TODO: pathing
# subtree.slot = subtree.declaration.slot
try:
path = subtree.env.get_declaration_path_for_name(name_to_str(subtree), args)
if not path:
return
subtree.assembly = "; name {dbg}\n".format(dbg=collect_debug_text(subtree))
if path[0].tag == "method" or path[0].tag == "abstract_method":
subtree.slot = this
if path[0].tag == "class":
subtree.slot = generate_new_stack_slot(subtree)
subtree.memory_location = generate_new_stack_slot(subtree)
mangled_name = mangle_field_name(path[1])
subtree.assembly += """
mov eax, {mangled_name}
mov ebx, DWORD [eax]
mov {memory_dst}, eax
mov {value_dst}, ebx
""".format(
mangled_name=mangled_name,
memory_dst=stack_slot_to_operand(subtree.memory_location),
value_dst=stack_slot_to_operand(subtree.slot),
)
path = path[1:]
elif path[0].tag == "field":
subtree.slot = generate_new_stack_slot(subtree)
subtree.memory_location = generate_new_stack_slot(subtree)
subtree.assembly += """
mov eax, DWORD [ebp + 8] ; this -> eax
mov ebx, [eax + {field_location}]
add eax, {field_location}
mov {mem_loc}, eax
mov {dest}, ebx
""".format(
field_location=path[0].field_offset * 4,
dest=stack_slot_to_operand(subtree.slot),
mem_loc=stack_slot_to_operand(subtree.memory_location),
)
elif path[0].tag == "local_variable_declaration" or path[0].tag == "param":
if not hasattr(path[0], "slot"):
return
subtree.slot = generate_new_stack_slot(subtree)
subtree.memory_location = generate_new_stack_slot(subtree)
subtree.assembly += """
mov eax, {source}
mov {dest}, eax
mov ebx, ebp
sub ebx, {source_stack_slot}
mov {mem_loc}, ebx
""".format(
source=stack_slot_to_operand(path[0].slot),
source_stack_slot=path[0].slot * 4,
mem_loc=stack_slot_to_operand(subtree.memory_location),
dest=stack_slot_to_operand(subtree.slot),
)
for child in path[1:]:
if child.tag in ["method", "abstract_method"]:
return
former_slot = subtree.slot
subtree.slot = generate_new_stack_slot(subtree)
subtree.memory_location = generate_new_stack_slot(subtree)
if not hasattr(subtree, "assembly"):
subtree.assembly = ""
subtree.assembly += """
mov eax, {former_location}
mov ebx, [eax + {field_location}]
add eax, {field_location}
mov {mem_loc}, eax
mov {dest}, ebx
""".format(
former_location=stack_slot_to_operand(former_slot),
field_location=child.field_offset * 4,
dest=stack_slot_to_operand(subtree.slot),
mem_loc=stack_slot_to_operand(subtree.memory_location),
)
except JoosSyntaxException:
pass