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Commit 54662e2

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Add object related opcodes
This patch add some opcodes about java objects. Pitifulvm supports object constructor and static methods of objects now. New opcodes: * aload, astore * dup * invokespecial * new * pop Add a new test script: "Constructor.java"
1 parent 1236eda commit 54662e2

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7 files changed

+251
-42
lines changed

7 files changed

+251
-42
lines changed

‎Makefile‎

Lines changed: 3 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -44,8 +44,9 @@ TESTS = \
4444
Primes \
4545
Recursion \
4646
Long \
47-
Caller
48-
47+
Caller \
48+
Constructor
49+
4950
check: $(addprefix tests/,$(TESTS:=-result.out))
5051

5152
ifneq (, $(shell which valgrind))

‎class-heap.c‎

Lines changed: 46 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -35,6 +35,52 @@ class_file_t *find_class_from_heap(char *value)
3535
return NULL;
3636
}
3737

38+
class_file_t *find_or_add_class_to_heap(char *class_name, char *prefix)
39+
{
40+
class_file_t *target_class = find_class_from_heap(class_name);
41+
42+
/* if class is not found, adding specific class path and finding
43+
* again. This can be removed by recording path infomation in class
44+
* heap
45+
*/
46+
if (!target_class && prefix) {
47+
char *tmp = malloc(strlen(class_name) + strlen(prefix) + 1);
48+
strcpy(tmp, prefix);
49+
strcat(tmp, class_name);
50+
target_class = find_class_from_heap(tmp);
51+
52+
free(tmp);
53+
}
54+
55+
/* if class is still not found, meaning that this class is not
56+
* loaded in class heap, so add it to the class heap. */
57+
if (!target_class) {
58+
char *tmp;
59+
if (prefix) {
60+
tmp = malloc(
61+
(strlen(class_name) + strlen(".class") + strlen(prefix) + 1));
62+
strcpy(tmp, prefix);
63+
strcat(tmp, class_name);
64+
} else {
65+
tmp = malloc(strlen(class_name) + strlen(".class") + 1);
66+
strcpy(tmp, class_name);
67+
}
68+
/* attempt to read given class file */
69+
FILE *class_file = fopen(strcat(tmp, ".class"), "r");
70+
assert(class_file && "Failed to open file");
71+
72+
/* parse the class file */
73+
target_class = malloc(sizeof(class_file_t));
74+
*target_class = get_class(class_file);
75+
int error = fclose(class_file);
76+
assert(!error && "Failed to close file");
77+
add_class(target_class, tmp);
78+
free(tmp);
79+
}
80+
81+
return target_class;
82+
}
83+
3884
void free_class_heap()
3985
{
4086
for (int i = 0; i < class_heap.length; ++i) {

‎class-heap.h‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -11,6 +11,7 @@ void init_class_heap();
1111
void free_class_heap();
1212
void add_class(class_file_t *clazz, char *name);
1313
class_file_t *find_class_from_heap(char *value);
14+
class_file_t *find_or_add_class_to_heap(char *class_name, char *prefix);
1415
char *find_method_info_from_index(uint16_t idx,
1516
class_file_t *clazz,
1617
char **name_info,

‎jvm.c‎

Lines changed: 146 additions & 40 deletions
Original file line numberDiff line numberDiff line change
@@ -30,6 +30,7 @@ typedef enum {
3030
i_ldc2_w = 0x14,
3131
i_iload = 0x15,
3232
i_lload = 0x16,
33+
i_aload = 0x19,
3334
i_iload_0 = 0x1a,
3435
i_iload_1 = 0x1b,
3536
i_iload_2 = 0x1c,
@@ -38,8 +39,13 @@ typedef enum {
3839
i_lload_1 = 0x1f,
3940
i_lload_2 = 0x20,
4041
i_lload_3 = 0x21,
42+
i_aload_0 = 0x2a,
43+
i_aload_1 = 0x2b,
44+
i_aload_2 = 0x2c,
45+
i_aload_3 = 0x2d,
4146
i_istore = 0x36,
4247
i_lstore = 0x37,
48+
i_astore = 0x3a,
4349
i_istore_0 = 0x3b,
4450
i_istore_1 = 0x3c,
4551
i_istore_2 = 0x3d,
@@ -48,6 +54,12 @@ typedef enum {
4854
i_lstore_1 = 0x40,
4955
i_lstore_2 = 0x41,
5056
i_lstore_3 = 0x42,
57+
i_astore_0 = 0x4b,
58+
i_astore_1 = 0x4c,
59+
i_astore_2 = 0x4d,
60+
i_astore_3 = 0x4e,
61+
i_pop = 0x57,
62+
i_dup = 0x59,
5163
i_iadd = 0x60,
5264
i_ladd = 0x61,
5365
i_isub = 0x64,
@@ -78,10 +90,13 @@ typedef enum {
7890
i_goto = 0xa7,
7991
i_ireturn = 0xac,
8092
i_lreturn = 0xad,
93+
i_areturn = 0xb0,
8194
i_return = 0xb1,
8295
i_getstatic = 0xb2,
8396
i_invokevirtual = 0xb6,
97+
i_invokespecial = 0xb7,
8498
i_invokestatic = 0xb8,
99+
i_new = 0xbb,
85100
} jvm_opcode_t;
86101

87102
/* TODO: add -cp arg to achieve class path select */
@@ -222,6 +237,18 @@ stack_entry_t *execute(method_t *method,
222237
return ret;
223238
}
224239

240+
/* Return long from method */
241+
case i_areturn: {
242+
stack_entry_t *ret = malloc(sizeof(stack_entry_t));
243+
ret->entry.ptr_value = pop_ref(op_stack);
244+
ret->type = STACK_ENTRY_REF;
245+
246+
free(op_stack->store);
247+
free(op_stack);
248+
249+
return ret;
250+
}
251+
225252
/* Return void from method */
226253
case i_return: {
227254
stack_entry_t *ret = malloc(sizeof(stack_entry_t));
@@ -242,47 +269,9 @@ stack_entry_t *execute(method_t *method,
242269
char *method_name, *method_descriptor, *class_name;
243270
class_name = find_method_info_from_index(index, clazz, &method_name,
244271
&method_descriptor);
245-
class_file_t *target_class = find_class_from_heap(class_name);
246-
247-
/* if class is not found, adding specific class path and finding
248-
* again. This can be removed by recording path infomation in class
249-
* heap
250-
*/
251-
if (!target_class && prefix) {
252-
char *tmp = malloc(strlen(class_name) + strlen(prefix) + 1);
253-
strcpy(tmp, prefix);
254-
strcat(tmp, class_name);
255-
target_class = find_class_from_heap(tmp);
256-
257-
free(tmp);
258-
}
259-
260-
/* if class is still not found, meaning that this class is not
261-
* loaded in class heap, so add it to the class heap. */
262-
if (!target_class) {
263-
char *tmp;
264-
if (prefix) {
265-
tmp = malloc((strlen(class_name) + strlen(".class") +
266-
strlen(prefix) + 1));
267-
strcpy(tmp, prefix);
268-
strcat(tmp, class_name);
269-
} else {
270-
tmp = malloc(strlen(class_name) + strlen(".class") + 1);
271-
strcpy(tmp, class_name);
272-
}
273-
/* attempt to read given class file */
274-
FILE *class_file = fopen(strcat(tmp, ".class"), "r");
275-
assert(class_file && "Failed to open file");
276-
277-
/* parse the class file */
278-
target_class = malloc(sizeof(class_file_t));
279-
*target_class = get_class(class_file);
280-
int error = fclose(class_file);
281-
assert(!error && "Failed to close file");
282-
add_class(target_class, tmp);
283-
free(tmp);
284-
}
285272

273+
class_file_t *target_class =
274+
find_or_add_class_to_heap(class_name, prefix);
286275
assert(target_class && "Failed to load class in invokestatic");
287276

288277
method_t *own_method =
@@ -301,6 +290,9 @@ stack_entry_t *execute(method_t *method,
301290
case STACK_ENTRY_LONG:
302291
push_long(op_stack, exec_res->entry.long_value);
303292
break;
293+
case STACK_ENTRY_REF:
294+
push_ref(op_stack, exec_res->entry.ptr_value);
295+
break;
304296
case STACK_ENTRY_NONE:
305297
/* nothing */
306298
break;
@@ -547,6 +539,18 @@ stack_entry_t *execute(method_t *method,
547539
break;
548540
}
549541

542+
/* Load object from local variable */
543+
case i_aload_0:
544+
case i_aload_1:
545+
case i_aload_2:
546+
case i_aload_3: {
547+
int32_t param = current - i_aload_0;
548+
object_t *obj = locals[param].entry.ptr_value;
549+
push_ref(op_stack, obj);
550+
pc += 1;
551+
break;
552+
}
553+
550554
/* Load int from local variable */
551555
case i_iload_0:
552556
case i_iload_1:
@@ -584,6 +588,15 @@ stack_entry_t *execute(method_t *method,
584588
break;
585589
}
586590

591+
/* Store object from local variable */
592+
case i_astore: {
593+
int32_t param = code_buf[pc + 1];
594+
locals[param].entry.ptr_value = pop_ref(op_stack);
595+
locals[param].type = STACK_ENTRY_REF;
596+
pc += 2;
597+
break;
598+
}
599+
587600
/* Store long into local variable */
588601
case i_lstore_0:
589602
case i_lstore_1:
@@ -621,6 +634,34 @@ stack_entry_t *execute(method_t *method,
621634
break;
622635
}
623636

637+
/* Store object from local variable */
638+
case i_astore_0:
639+
case i_astore_1:
640+
case i_astore_2:
641+
case i_astore_3: {
642+
int32_t param = current - i_astore_0;
643+
locals[param].entry.ptr_value = pop_ref(op_stack);
644+
locals[param].type = STACK_ENTRY_REF;
645+
pc += 1;
646+
break;
647+
}
648+
649+
/* discard the top value on the stack */
650+
case i_pop: {
651+
op_stack->size--;
652+
pc += 1;
653+
break;
654+
}
655+
656+
/* duplicate the value on top of the stack */
657+
case i_dup: {
658+
op_stack->store[op_stack->size] =
659+
op_stack->store[op_stack->size - 1];
660+
op_stack->size++;
661+
pc += 1;
662+
break;
663+
}
664+
624665
/* Increment local variable by constant */
625666
case i_iinc: {
626667
uint8_t i = code_buf[pc + 1];
@@ -778,6 +819,71 @@ stack_entry_t *execute(method_t *method,
778819
pc += 3;
779820
break;
780821

822+
/* create new object */
823+
case i_new: {
824+
uint8_t param1 = code_buf[pc + 1], param2 = code_buf[pc + 2];
825+
uint16_t index = ((param1 << 8) | param2);
826+
827+
char *class_name = find_class_name_from_index(index, clazz);
828+
class_file_t *target_class =
829+
find_or_add_class_to_heap(class_name, prefix);
830+
assert(target_class && "Failed to load class in new");
831+
832+
object_t *object = create_object(target_class);
833+
push_ref(op_stack, object);
834+
835+
pc += 3;
836+
break;
837+
}
838+
839+
/* Invoke object constructor method */
840+
case i_invokespecial: {
841+
uint8_t param1 = code_buf[pc + 1], param2 = code_buf[pc + 2];
842+
uint16_t index = ((param1 << 8) | param2);
843+
844+
/* the method to be called */
845+
char *method_name, *method_descriptor, *class_name;
846+
class_name = find_method_info_from_index(index, clazz, &method_name,
847+
&method_descriptor);
848+
849+
/* java.lang.Object is the parent for every object, so every object
850+
* will finally call java.lang.Object's constructor */
851+
if (!strcmp(class_name, "java/lang/Object")) {
852+
pop_ref(op_stack);
853+
pc += 3;
854+
break;
855+
}
856+
857+
class_file_t *target_class =
858+
find_or_add_class_to_heap(class_name, prefix);
859+
assert(target_class && "Failed to load class in i_invokespecial");
860+
861+
/* find constructor method from class */
862+
method_t *constructor =
863+
find_method(method_name, method_descriptor, target_class);
864+
865+
/* prepare local variables */
866+
uint16_t num_params = get_number_of_parameters(constructor);
867+
local_variable_t own_locals[constructor->code.max_locals];
868+
for (int i = num_params; i >= 1; i--) {
869+
pop_to_local(op_stack, &own_locals[i]);
870+
}
871+
872+
/* first argument must be object itself */
873+
object_t *obj = pop_ref(op_stack);
874+
own_locals[0].entry.ptr_value = obj;
875+
own_locals[0].type = STACK_ENTRY_REF;
876+
877+
stack_entry_t *exec_res =
878+
execute(constructor, own_locals, target_class);
879+
assert(exec_res->type == STACK_ENTRY_NONE &&
880+
"A constructor must not return a value.");
881+
free(exec_res);
882+
883+
pc += 3;
884+
break;
885+
}
886+
781887
default:
782888
fprintf(stderr, "Unknown instruction %x\n", current);
783889
exit(1);

‎stack.c‎

Lines changed: 12 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -36,6 +36,13 @@ void push_long(stack_frame_t *stack, int64_t value)
3636
stack->size++;
3737
}
3838

39+
void push_ref(stack_frame_t *stack, void *addr)
40+
{
41+
stack->store[stack->size].entry.ptr_value = addr;
42+
stack->store[stack->size].type = STACK_ENTRY_REF;
43+
stack->size++;
44+
}
45+
3946
/* pop top of stack value and convert to 64 bits integer */
4047
int64_t stack_to_int(value_t *entry, size_t size)
4148
{
@@ -66,6 +73,11 @@ int64_t pop_int(stack_frame_t *stack)
6673
return value;
6774
}
6875

76+
void *pop_ref(stack_frame_t *stack)
77+
{
78+
return stack->store[--stack->size].entry.ptr_value;
79+
}
80+
6981
void pop_to_local(stack_frame_t *stack, local_variable_t *locals)
7082
{
7183
stack_entry_type_t type = stack->store[stack->size - 1].type;

‎stack.h‎

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -38,7 +38,9 @@ void push_byte(stack_frame_t *stack, int8_t value);
3838
void push_short(stack_frame_t *stack, int16_t value);
3939
void push_int(stack_frame_t *stack, int32_t value);
4040
void push_long(stack_frame_t *stack, int64_t value);
41+
void push_ref(stack_frame_t *stack, void *addr);
4142
int64_t pop_int(stack_frame_t *stack);
43+
void *pop_ref(stack_frame_t *stack);
4244
void pop_to_local(stack_frame_t *stack, local_variable_t *locals);
4345
size_t get_type_size(stack_entry_type_t type);
4446
int64_t stack_to_int(value_t *entry, size_t size);

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