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labelnode.cc Go to the documentation of this file. // $Id: labelnode.cc,v 1.3 2003/08/07 23:13:08 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 // -------------------------------------------------------------------- labelNode::labelNode(const char * name, stmtNode * stmt, const Coord coord) : targetNode(Label, stmt, coord), _name(string(name)), _references() {} // -- Used in BuildLabel and ResolveGoto in procedure.c labelNode::labelNode(idNode * ident, stmtNode * the_stmt) : targetNode(Label, the_stmt, ident->coord()), _name(ident->name()), _references() { /* -- NOTE: This is all made obsolete by goto_label_walker.... labelNode * orig = Symbols::Labels->insert(ident->text(), this); if (orig) { // -- Conflict if ( ! is_undeclared() ) if ( ! orig->is_undeclared() ) CBZ::SyntaxError(coord(), string("multiple definitions of label `") + orig->name() + string("'")); else { // -- Original is undeclared // Loop over all the references to the old one and point them here. goto_list & olist = orig->references(); goto_list_p p; for (p = olist.begin(); p != olist.end(); ++p) (*p)->label(this); // -- Prevent EndOfScope checker from whining orig->stmt((blockNode *)0); _references = orig->references(); } } */ } // -- Build an undeclared label (used in ResolveGoto when we reach // a goto before seeing the label. // Now obsolete. labelNode::labelNode(idNode * ident) : targetNode(Label, (stmtNode *) 0, ident->coord()), _name(ident->name()), _references() { // labelNode * orig = Symbols::Labels->insert(ident->text(), this); } // ------------------------------------------------------------ // Undeclared // ------------------------------------------------------------ // A label is undeclared if it has a stmt(), but the statement // is of type "Undeclared". bool labelNode::is_undeclared() const { return (stmt() && stmt()->typ() == Undeclared); } // ------------------------------------------------------------ // Walker // ------------------------------------------------------------ void labelNode::visit(Visitor * the_visitor) { the_visitor->at_label(this); } void labelNode::walk(Walker & the_walker) { Walker::Order ord = the_walker.order(); if (ord == Walker::Preorder || ord == Walker::Both) the_walker.at_label(this, Walker::Preorder); if (the_walker.depth() == Walker::Subtree) { // -- Visit the children if (stmt()) stmt()->walk(the_walker); } if (ord == Walker::Postorder || ord == Walker::Both) the_walker.at_label(this, Walker::Postorder); } // ------------------------------------------------------------ // Dataflow // ------------------------------------------------------------ void labelNode::dataflow(FlowVal * v, FlowProblem & fp) { if (fp.forward()) { v->meet(at_entry()); fp.flow_label(v, this, FlowProblem::Entry); if (stmt()) stmt()->dataflow(v, fp); fp.flow_label(v, this, FlowProblem::Exit); } else { fp.flow_label(v, this, FlowProblem::Exit); if (stmt()) stmt()->dataflow(v, fp); fp.flow_label(v, this, FlowProblem::Entry); v->meet(at_entry()); } } // ------------------------------------------------------------ // Output // ------------------------------------------------------------ void labelNode::output_stmt(output_context & ct, Node * parent) { ct << name() << ':'; if (stmt()) stmt()->output(ct, this); else ct << ';'; } // ------------------------------------------------------------ // Changer // ------------------------------------------------------------ Node * labelNode::change(Changer & the_changer, bool redispatch) { Changer::Order ord = the_changer.order(); labelNode * the_label = this; if ((ord == Changer::Preorder || ord == Changer::Both) && ! redispatch) the_label = (labelNode *) the_changer.at_label(the_label, Changer::Preorder); if (the_label) { if (the_label != this) return the_label->change(the_changer, true); blockNode * old_stmt = the_label->stmt(); if (old_stmt) { blockNode * new_stmt = (blockNode *) old_stmt->change(the_changer); if (old_stmt != new_stmt) { //if (the_changer.delete_old()) //delete old_stmt; the_label->stmt(new_stmt); } } } if ((ord == Changer::Postorder || ord == Changer::Both) && ! redispatch) the_label = (labelNode *) the_changer.at_label(the_label, Changer::Postorder); return the_label; } // ------------------------------------------------------------ // Destructor // ------------------------------------------------------------ labelNode::~labelNode() { }

Generated on August 27, 2003
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