def c_gen_code(self):
import code_gen.asm.common as common
CodeGenManager.N_PARAMS = self.c_num_params
CodeGenManager.cur_method = self
body_code = []
if self.body:
body_code = self.body.c_gen_code()
constructor_code = []
# Each constructor does the three tasks:
# 1. Call parent constructor (if one exists).
# 2. Set field values.
# 3. Run constructor body.
if self.is_constructor:
parent_code = []
if self.parent_type.canonical_name != 'java.lang.Object':
super_class = self.parent_type.super[0].definition
super_sig = (str(super_class.name), [])
super_constructor, _ = super_class.environment.lookup_method(super_sig,
constructor=True)
parent_code = [
common.get_param('eax', 0, self.c_num_params),
'push eax',
'call {0}'.format(super_constructor.c_defn_label),
'pop ebx ; pop to garbage',
]
field_init_code = []
for f in self.parent_type.fields:
if f.is_static:
continue
field_init_code.append([
'; setting value for field {0}'.format(str(f.identifier)),
'push eax ; save |this|',
code_gen.asm.object.create_starting_value(f),
'mov ebx, eax ; move result to ebx',
'pop eax ; restore |this|',
common.save_instance_field('eax', f, 'ebx'),
])
constructor_code = [
parent_code,
field_init_code,
]
ret = [
'global {0}'.format(self.c_defn_label),
'{0}:'.format(self.c_defn_label),
common.function_prologue(self.c_num_local_vars * 4),
constructor_code,
body_code,
common.function_epilogue(),
]
CodeGenManager.N_PARAMS = 0
CodeGenManager.cur_method = None
return ret
def c_gen_code(self):
asm = []
# Generate code for the return expression, if there is one
if self.children[0] is not None:
asm.append(self.children[0].c_gen_code())
asm.append(asm_common.function_epilogue())
return asm
def create_array(is_primitive, array_cit_label, subtype_offset = 0):
''' Returns code for a function that creates an array in memory.
This function does NOT include a label, because each reference/primitive
type will need their own version of this function. You should put your
own label above this code.
Structure of the created array object is as follows:
1. Pointer to Array CIT
2. The type's subtype column offset for reference types, 0 for primitives
3. Length (reference to a integer)
4. Array elements
1 Param:
The length of the array (a reference to an integer)'''
N_PARAMS = 1
# The first 12 bytes are for the pointer to the Array CIT, the subtype column
# offset, and the length. Remaining bytes are for the array elements
# (4 bytes each)
array_length_pass = CodeGenManager.get_label('array_length_pass')
return [
common.function_prologue(),
common.get_param('ebx', 0, N_PARAMS),
common.unwrap_primitive('ebx', 'ebx'),
'; ebx now contains the length of the array',
'; check that array length is not negative:',
'cmp ebx, 0',
'jge {0}'.format(array_length_pass),
'call __exception',
'{0}:'.format(array_length_pass),
'push ebx ; store the array length (# elems)',
'; calculate how much memory to allocate, based on length of array:',
'imul ebx, 4 ; 4 bytes for every element',
'add ebx, 12 ; add an extra 12 bytes for pointers/length field',
common.malloc_reg('ebx'),
'pop ebx ; restore length (# elems)',
'mov edx, eax ; save pointer to array memory in edx',
'push eax',
'; set array elems to their default values:',
_array_init_loop(is_primitive),
'; create an int to store the length of the array:',
'push ebx;',
'call _create_int',
'pop ecx; pop param to garbage',
'mov ebx, eax ; ebx has pointer to integer representing array length',
'pop eax ; eax now has pointer to memory from malloc call',
'mov dword [eax], {0}'.format(array_cit_label),
'mov dword [eax + 4], {0}'.format(subtype_offset*4),
'mov dword [eax + 8], ebx',
common.function_epilogue()
]