C-Breeze C Compiler Infrastructure [ Project home page]

returnnode.cc Go to the documentation of this file. // $Id: returnnode.cc,v 1.4 2003/08/07 23:13:11 pnav Exp $ // ---------------------------------------------------------------------- // // C-Breeze // C Compiler Framework // // Copyright (c) 2000 University of Texas at Austin // // Samuel Z. Guyer // Daniel A. Jimenez // Calvin Lin // // Permission is hereby granted, free of charge, to any person // obtaining a copy of this software and associated documentation // files (the "Software"), to deal in the Software without // restriction, including without limitation the rights to use, copy, // modify, merge, publish, distribute, sublicense, and/or sell copies // of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be // included in all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND // NONINFRINGEMENT. IN NO EVENT SHALL THE UNIVERSITY OF TEXAS AT // AUSTIN BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER // IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF // OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN // THE SOFTWARE. // // We acknowledge the C-to-C Translator from MIT Laboratory for // Computer Science for inspiring parts of the C-Breeze design. // // ---------------------------------------------------------------------- #include "c_breeze.h" // -------------------------------------------------------------------- // Constructors // -------------------------------------------------------------------- returnNode::returnNode(exprNode * expr, procNode * proc, const Coord coord) : jumpNode(Return, coord), _expr(expr), _proc(proc), _is_proc_exit(false) {} returnNode::returnNode(exprNode * expr, procNode * proc, bool proc_exit, const Coord coord): jumpNode(Return, coord), _expr(expr), _proc(proc), _is_proc_exit(proc_exit) {} // ------------------------------------------------------------ // Walker // ------------------------------------------------------------ void returnNode::visit(Visitor * the_visitor) { the_visitor->at_return(this); } void returnNode::walk(Walker & the_walker) { Walker::Order ord = the_walker.order(); if (ord == Walker::Preorder || ord == Walker::Both) the_walker.at_return(this, Walker::Preorder); if (the_walker.depth() == Walker::Subtree) { // -- Visit the children if (expr()) expr()->walk(the_walker); } if (ord == Walker::Postorder || ord == Walker::Both) the_walker.at_return(this, Walker::Postorder); } // ------------------------------------------------------------ // Dataflow // ------------------------------------------------------------ void returnNode::dataflow(FlowVal * v, FlowProblem & fp) { if (fp.forward()) { fp.flow_return(v, this, FlowProblem::Entry); // -- Dataflow the expr and push values to end of the procedure if (expr()) if (fp.basicblocks()) { fp.flow_basicblock(v, expr(), FlowProblem::Entry); fp.flow_basicblock(v, expr(), FlowProblem::Exit); } else expr()->dataflow(v, fp); if (proc()) proc()->at_exit()->meet_and_diff(v, fp); v->to_top(); fp.flow_return(v, this, FlowProblem::Exit); } else { fp.flow_return(v, this, FlowProblem::Exit); // -- Get values from the end of the procedure v->to_top(); if (proc()) v->meet(proc()->at_exit()); if (expr()) if (fp.basicblocks()) { fp.flow_basicblock(v, expr(), FlowProblem::Exit); fp.flow_basicblock(v, expr(), FlowProblem::Entry); } else expr()->dataflow(v, fp); fp.flow_return(v, this, FlowProblem::Entry); } } // clone() must be different here to ensure that we only ever have // one returnNode that claims to be the procedure exit per procNode Node * returnNode::clone() const { returnNode * ret = new returnNode(*this); ret->proc_exit(false); return ret; } // ------------------------------------------------------------ // Output // ------------------------------------------------------------ void returnNode::output_stmt(output_context & ct, Node * parent) { ct << "return "; if (expr()) expr()->output(ct, this); ct << ';'; } // ------------------------------------------------------------ // Changer // ------------------------------------------------------------ Node * returnNode::change(Changer & the_changer, bool redispatch) { Changer::Order ord = the_changer.order(); returnNode * the_return = this; if ((ord == Changer::Preorder || ord == Changer::Both) && ! redispatch) the_return = (returnNode *) the_changer.at_return(the_return, Changer::Preorder); if (the_return) { if (the_return != this) return the_return->change(the_changer, true); exprNode * old_expr = the_return->expr(); if (old_expr) { exprNode * new_expr = (exprNode *) old_expr->change(the_changer); if (old_expr != new_expr) { //if (the_changer.delete_old()) //delete old_expr; the_return->expr(new_expr); } } } if ((ord == Changer::Postorder || ord == Changer::Both) && ! redispatch) the_return = (returnNode *) the_changer.at_return(the_return, Changer::Postorder); return the_return; } // ------------------------------------------------------------ // Destructor // ------------------------------------------------------------ returnNode::~returnNode() { //delete _expr; }

Generated on August 27, 2003
Back to the C-Breeze home page