134 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C++
		
	
	
			
		
		
	
	
			134 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C++
		
	
	
| #include "master.hpp"
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| 
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| namespace factor {
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| 
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| callstack* factor_vm::allot_callstack(cell size) {
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|   callstack* stack = allot<callstack>(callstack_object_size(size));
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|   stack->length = tag_fixnum(size);
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|   return stack;
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| }
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| 
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| /* We ignore the two topmost frames, the 'callstack' primitive
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| frame itself, and the frame calling the 'callstack' primitive,
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| so that set-callstack doesn't get stuck in an infinite loop.
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| 
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| This means that if 'callstack' is called in tail position, we
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| will have popped a necessary frame... however this word is only
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| called by continuation implementation, and user code shouldn't
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| be calling it at all, so we leave it as it is for now. */
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| void* factor_vm::second_from_top_stack_frame(context* ctx) {
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|   void* frame_top = ctx->callstack_top;
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|   for (cell i = 0; i < 2; ++i) {
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|     void* pred = frame_predecessor(frame_top);
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|     if (pred >= ctx->callstack_bottom)
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|       return frame_top;
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|     frame_top = pred;
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|   }
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|   return frame_top;
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| }
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| 
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| cell factor_vm::capture_callstack(context* ctx) {
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|   void* top = second_from_top_stack_frame(ctx);
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|   void* bottom = ctx->callstack_bottom;
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| 
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|   fixnum size = std::max((fixnum)0, (fixnum)bottom - (fixnum)top);
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| 
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|   callstack* stack = allot_callstack(size);
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|   memcpy(stack->top(), top, size);
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|   return tag<callstack>(stack);
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| }
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| 
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| void factor_vm::primitive_callstack() { ctx->push(capture_callstack(ctx)); }
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| 
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| void factor_vm::primitive_callstack_for() {
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|   context* other_ctx = (context*)pinned_alien_offset(ctx->peek());
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|   ctx->replace(capture_callstack(other_ctx));
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| }
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| 
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| void* factor_vm::frame_predecessor(void* frame_top) {
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|   void* addr = frame_return_address((void*)frame_top);
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|   FACTOR_ASSERT(addr != 0);
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|   code_block* owner = code->code_block_for_address((cell)addr);
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|   cell frame_size = owner->stack_frame_size_for_address((cell)addr);
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|   return (void*)((char*)frame_top + frame_size);
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| }
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| 
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| struct stack_frame_accumulator {
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|   factor_vm* parent;
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|   growable_array frames;
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| 
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|   explicit stack_frame_accumulator(factor_vm* parent)
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|       : parent(parent), frames(parent) {}
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| 
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|   void operator()(void* frame_top, cell frame_size, code_block* owner,
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|                   void* addr) {
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|     data_root<object> executing_quot(owner->owner_quot(), parent);
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|     data_root<object> executing(owner->owner, parent);
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|     data_root<object> scan(owner->scan(parent, addr), parent);
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| 
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|     frames.add(executing.value());
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|     frames.add(executing_quot.value());
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|     frames.add(scan.value());
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|   }
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| };
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| 
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| struct stack_frame_in_array {
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|   cell cells[3];
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| };
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| 
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| void factor_vm::primitive_callstack_to_array() {
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|   data_root<callstack> callstack(ctx->peek(), this);
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| 
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|   stack_frame_accumulator accum(this);
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|   iterate_callstack_object(callstack.untagged(), accum);
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| 
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|   /* The callstack iterator visits frames in reverse order (top to bottom) */
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|   std::reverse((stack_frame_in_array*)accum.frames.elements->data(),
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|                (stack_frame_in_array*)(accum.frames.elements->data() +
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|                                        accum.frames.count));
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| 
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|   accum.frames.trim();
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| 
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|   ctx->replace(accum.frames.elements.value());
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| 
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| }
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| 
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| /* Some primitives implementing a limited form of callstack mutation.
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| Used by the single stepper. */
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| void factor_vm::primitive_innermost_stack_frame_executing() {
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|   callstack* stack = untag_check<callstack>(ctx->peek());
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|   void* frame = stack->top();
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|   void* addr = frame_return_address(frame);
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|   ctx->replace(code->code_block_for_address((cell)addr)->owner_quot());
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| }
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| 
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| void factor_vm::primitive_innermost_stack_frame_scan() {
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|   callstack* stack = untag_check<callstack>(ctx->peek());
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|   void* frame = stack->top();
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|   void* addr = frame_return_address(frame);
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|   ctx->replace(code->code_block_for_address((cell)addr)->scan(this, addr));
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| }
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| 
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| void factor_vm::primitive_set_innermost_stack_frame_quot() {
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|   data_root<callstack> stack(ctx->pop(), this);
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|   data_root<quotation> quot(ctx->pop(), this);
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| 
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|   stack.untag_check(this);
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|   quot.untag_check(this);
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| 
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|   jit_compile_quot(quot.value(), true);
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| 
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|   void* inner = stack->top();
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|   void* addr = frame_return_address(inner);
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|   code_block* block = code->code_block_for_address((cell)addr);
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|   cell offset = block->offset(addr);
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|   set_frame_return_address(inner, (char*)quot->entry_point + offset);
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| }
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| 
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| void factor_vm::primitive_callstack_bounds() {
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|   ctx->push(allot_alien((void*)ctx->callstack_seg->start));
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|   ctx->push(allot_alien((void*)ctx->callstack_seg->end));
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| }
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| 
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| }
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