5 /* Allocates memory (allot) */
6 callstack* factor_vm::allot_callstack(cell size) {
7 callstack* stack = allot<callstack>(callstack_object_size(size));
8 stack->length = tag_fixnum(size);
12 /* We ignore the two topmost frames, the 'callstack' primitive
13 frame itself, and the frame calling the 'callstack' primitive,
14 so that set-callstack doesn't get stuck in an infinite loop.
16 This means that if 'callstack' is called in tail position, we
17 will have popped a necessary frame... however this word is only
18 called by continuation implementation, and user code shouldn't
19 be calling it at all, so we leave it as it is for now. */
20 cell factor_vm::second_from_top_stack_frame(context* ctx) {
21 cell frame_top = ctx->callstack_top;
22 for (cell i = 0; i < 2; ++i) {
23 cell pred = code->frame_predecessor(frame_top);
24 if (pred >= ctx->callstack_bottom)
31 /* Allocates memory (allot_callstack) */
32 cell factor_vm::capture_callstack(context* ctx) {
33 cell top = second_from_top_stack_frame(ctx);
34 cell bottom = ctx->callstack_bottom;
36 fixnum size = std::max((cell)0, bottom - top);
38 callstack* stack = allot_callstack(size);
39 memcpy(stack->top(), (void *)top, size);
40 return tag<callstack>(stack);
43 /* Allocates memory (capture_callstack) */
44 void factor_vm::primitive_callstack() { ctx->push(capture_callstack(ctx)); }
46 /* Allocates memory (capture_callstack) */
47 void factor_vm::primitive_callstack_for() {
48 context* other_ctx = (context*)pinned_alien_offset(ctx->peek());
49 ctx->replace(capture_callstack(other_ctx));
52 struct stack_frame_in_array {
56 /* Allocates memory (frames.trim()), iterate_callstack_object() */
57 void factor_vm::primitive_callstack_to_array() {
58 data_root<callstack> callstack(ctx->peek(), this);
59 /* Allocates memory here. */
60 growable_array frames(this);
62 auto stack_frame_accumulator = [&](cell frame_top,
66 data_root<object> executing_quot(owner->owner_quot(), this);
67 data_root<object> executing(owner->owner, this);
68 data_root<object> scan(owner->scan(this, addr), this);
70 frames.add(executing.value());
71 frames.add(executing_quot.value());
72 frames.add(scan.value());
74 iterate_callstack_object(callstack.untagged(), stack_frame_accumulator);
76 /* The callstack iterator visits frames in reverse order (top to bottom) */
77 std::reverse((stack_frame_in_array*)frames.elements->data(),
78 (stack_frame_in_array*)(frames.elements->data() +
82 ctx->replace(frames.elements.value());
85 /* Some primitives implementing a limited form of callstack mutation.
86 Used by the single stepper. */
87 void factor_vm::primitive_innermost_stack_frame_executing() {
88 callstack* stack = untag_check<callstack>(ctx->peek());
89 void* frame = stack->top();
90 cell addr = *(cell*)frame;
91 ctx->replace(code->code_block_for_address(addr)->owner_quot());
94 void factor_vm::primitive_innermost_stack_frame_scan() {
95 callstack* stack = untag_check<callstack>(ctx->peek());
96 void* frame = stack->top();
97 cell addr = *(cell*)frame;
98 ctx->replace(code->code_block_for_address(addr)->scan(this, addr));
101 /* Allocates memory (jit_compile_quotation) */
102 void factor_vm::primitive_set_innermost_stack_frame_quotation() {
103 data_root<callstack> stack(ctx->pop(), this);
104 data_root<quotation> quot(ctx->pop(), this);
106 stack.untag_check(this);
107 quot.untag_check(this);
109 jit_compile_quotation(quot.value(), true);
111 void* inner = stack->top();
112 cell addr = *(cell*)inner;
113 code_block* block = code->code_block_for_address(addr);
114 cell offset = block->offset(addr);
115 *(cell*)inner = quot->entry_point + offset;
118 /* Allocates memory (allot_alien) */
119 void factor_vm::primitive_callstack_bounds() {
120 ctx->push(allot_alien((void*)ctx->callstack_seg->start));
121 ctx->push(allot_alien((void*)ctx->callstack_seg->end));