6 void factor_vm::check_frame(stack_frame *frame)
9 check_code_pointer((cell)frame->entry_point);
10 assert(frame->size != 0);
14 callstack *factor_vm::allot_callstack(cell size)
16 callstack *stack = allot<callstack>(callstack_object_size(size));
17 stack->length = tag_fixnum(size);
21 /* If 'stack' points into the middle of the frame, find the nearest valid stack
22 pointer where we can resume execution and hope to capture the call trace without
23 crashing. Also, make sure we have at least 'stack_reserved' bytes available so
24 that we don't run out of callstack space while handling the error. */
25 stack_frame *factor_vm::fix_callstack_top(stack_frame *stack)
27 stack_frame *frame = ctx->callstack_bottom - 1;
30 && frame >= ctx->callstack_top
31 && (cell)frame >= ctx->callstack_seg->start + stack_reserved)
32 frame = frame_successor(frame);
37 /* We ignore the two topmost frames, the 'callstack' primitive
38 frame itself, and the frame calling the 'callstack' primitive,
39 so that set-callstack doesn't get stuck in an infinite loop.
41 This means that if 'callstack' is called in tail position, we
42 will have popped a necessary frame... however this word is only
43 called by continuation implementation, and user code shouldn't
44 be calling it at all, so we leave it as it is for now. */
45 stack_frame *factor_vm::second_from_top_stack_frame(context *ctx)
47 stack_frame *frame = ctx->callstack_bottom - 1;
48 while(frame >= ctx->callstack_top
49 && frame_successor(frame) >= ctx->callstack_top
50 && frame_successor(frame_successor(frame)) >= ctx->callstack_top)
52 frame = frame_successor(frame);
57 cell factor_vm::capture_callstack(context *ctx)
59 stack_frame *top = second_from_top_stack_frame(ctx);
60 stack_frame *bottom = ctx->callstack_bottom;
62 fixnum size = std::max((fixnum)0,(fixnum)bottom - (fixnum)top);
64 callstack *stack = allot_callstack(size);
65 memcpy(stack->top(),top,size);
66 return tag<callstack>(stack);
69 void factor_vm::primitive_callstack()
71 ctx->push(capture_callstack(ctx));
74 void factor_vm::primitive_callstack_for()
76 context *other_ctx = (context *)pinned_alien_offset(ctx->pop());
77 ctx->push(capture_callstack(other_ctx));
80 code_block *factor_vm::frame_code(stack_frame *frame)
83 return (code_block *)frame->entry_point - 1;
86 code_block_type factor_vm::frame_type(stack_frame *frame)
88 return frame_code(frame)->type();
91 cell factor_vm::frame_executing(stack_frame *frame)
93 return frame_code(frame)->owner;
96 cell factor_vm::frame_executing_quot(stack_frame *frame)
98 tagged<object> executing(frame_executing(frame));
99 code_block *compiled = frame_code(frame);
100 if(!compiled->optimized_p() && executing->type() == WORD_TYPE)
101 executing = executing.as<word>()->def;
102 return executing.value();
105 stack_frame *factor_vm::frame_successor(stack_frame *frame)
108 return (stack_frame *)((cell)frame - frame->size);
111 cell factor_vm::frame_offset(stack_frame *frame)
113 char *entry_point = (char *)frame_code(frame)->entry_point();
114 char *return_address = (char *)FRAME_RETURN_ADDRESS(frame,this);
116 return return_address - entry_point;
121 void factor_vm::set_frame_offset(stack_frame *frame, cell offset)
123 char *entry_point = (char *)frame_code(frame)->entry_point();
124 if(offset == (cell)-1)
125 FRAME_RETURN_ADDRESS(frame,this) = NULL;
127 FRAME_RETURN_ADDRESS(frame,this) = entry_point + offset;
130 cell factor_vm::frame_scan(stack_frame *frame)
132 switch(frame_type(frame))
134 case code_block_unoptimized:
136 tagged<object> obj(frame_executing(frame));
137 if(obj.type_p(WORD_TYPE))
138 obj = obj.as<word>()->def;
140 if(obj.type_p(QUOTATION_TYPE))
141 return tag_fixnum(quot_code_offset_to_scan(obj.value(),frame_offset(frame)));
145 case code_block_optimized:
148 critical_error("Bad frame type",frame_type(frame));
153 struct stack_frame_accumulator {
155 growable_array frames;
157 explicit stack_frame_accumulator(factor_vm *parent_) : parent(parent_), frames(parent_) {}
159 void operator()(stack_frame *frame)
161 data_root<object> executing_quot(parent->frame_executing_quot(frame),parent);
162 data_root<object> executing(parent->frame_executing(frame),parent);
163 data_root<object> scan(parent->frame_scan(frame),parent);
165 frames.add(executing.value());
166 frames.add(executing_quot.value());
167 frames.add(scan.value());
171 void factor_vm::primitive_callstack_to_array()
173 data_root<callstack> callstack(ctx->pop(),this);
175 stack_frame_accumulator accum(this);
176 iterate_callstack_object(callstack.untagged(),accum);
179 ctx->push(accum.frames.elements.value());
182 stack_frame *factor_vm::innermost_stack_frame(callstack *stack)
184 stack_frame *top = stack->top();
185 stack_frame *bottom = stack->bottom();
186 stack_frame *frame = bottom - 1;
188 while(frame >= top && frame_successor(frame) >= top)
189 frame = frame_successor(frame);
194 /* Some primitives implementing a limited form of callstack mutation.
195 Used by the single stepper. */
196 void factor_vm::primitive_innermost_stack_frame_executing()
198 stack_frame *frame = innermost_stack_frame(untag_check<callstack>(ctx->pop()));
199 ctx->push(frame_executing_quot(frame));
202 void factor_vm::primitive_innermost_stack_frame_scan()
204 stack_frame *frame = innermost_stack_frame(untag_check<callstack>(ctx->pop()));
205 ctx->push(frame_scan(frame));
208 void factor_vm::primitive_set_innermost_stack_frame_quot()
210 data_root<callstack> callstack(ctx->pop(),this);
211 data_root<quotation> quot(ctx->pop(),this);
213 callstack.untag_check(this);
214 quot.untag_check(this);
216 jit_compile_quot(quot.value(),true);
218 stack_frame *inner = innermost_stack_frame(callstack.untagged());
219 cell offset = frame_offset(inner);
220 inner->entry_point = quot->entry_point;
221 set_frame_offset(inner,offset);
224 void factor_vm::primitive_callstack_bounds()
226 ctx->push(allot_alien((void*)ctx->callstack_seg->start));
227 ctx->push(allot_alien((void*)ctx->callstack_seg->end));