Viewing file:  Flow_visitor.cpp (1.73 KB) -rw-rw-r--
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/*
* phc -- the open source PHP compiler
* See doc/license/README.license for licensing information
*
* Base class for data-flow analyses.
*/
#include "Flow_visitor.h"
Flow_visitor::Flow_visitor (Flow_visitor_direction direction)
: direction (direction)
{
}
void
Flow_visitor::run (CFG* cfg)
{
foreach (Basic_block* bb, *cfg->get_all_bbs ())
{
this->init_block (bb);
visit_block (bb);
}
// Add the each block to the worklist
BB_list* worklist = get_initial_worklist (cfg);
// iterate until the worklist is no more
while (not worklist->empty ())
{
// Process the front block
Basic_block* bb = worklist->front ();
worklist->pop_front ();
visit_transfer_functions (bb, cfg);
if (this->solution_has_changed (bb))
{
foreach (Basic_block* next, *get_next_cfg_nodes (bb, cfg))
worklist->push_back (next);
}
}
// After the pure analysis section, apply the results (once).
foreach (Basic_block* bb, *cfg->get_all_bbs ())
transform_block (bb);
// Call the pass' own post-processing.
post_pass (cfg);
}
BB_list*
Flow_visitor::get_next_cfg_nodes (Basic_block* bb, CFG* cfg)
{
if (direction == FORWARD_FLOW)
return bb->get_successors ();
else
return bb->get_predecessors ();
}
void
Flow_visitor::visit_transfer_functions (Basic_block* bb, CFG* cfg)
{
if (direction == FORWARD_FLOW)
{
this->transfer_in (bb, bb->get_predecessors ());
this->transfer_out (bb, bb->get_successors ());
}
else
{
this->transfer_out (bb, bb->get_successors ());
this->transfer_in (bb, bb->get_predecessors ());
}
}
BB_list*
Flow_visitor::get_initial_worklist (CFG* cfg)
{
if (direction == FORWARD_FLOW)
return cfg->get_all_bbs_top_down ();
else
return cfg->get_all_bbs_bottom_up ();
}
void
Flow_visitor::post_pass (CFG* cfg)
{
}
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