source: src/Parser/StatementNode.cc @ 71a422a

//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// StatementNode.cc -- Transform from parse data-structures to AST data-structures, usually deleting the parse
//     data-structure after the transformation.
//
// Author           : Rodolfo G. Esteves
// Created On       : Sat May 16 14:59:41 2015
// Last Modified By : Andrew Beach
// Last Modified On : Tue Apr 11 10:16:00 2023
// Update Count     : 428
//

#include "StatementNode.h"

#include <cassert>                 // for assert, strict_dynamic_cast, assertf
#include <memory>                  // for unique_ptr
#include <string>                  // for string

#include "AST/Label.hpp"           // for Label
#include "AST/Stmt.hpp"            // for Stmt, AsmStmt, BranchStmt, CaseCla...
#include "Common/SemanticError.h"  // for SemanticError
#include "Common/utility.h"        // for maybeMoveBuild, maybeBuild
#include "DeclarationNode.h"       // for DeclarationNode
#include "ExpressionNode.h"        // for ExpressionNode
#include "parserutility.h"         // for notZeroExpr

class Declaration;

using namespace std;

// Some helpers for cases that really want a single node but check for lists.
static const ast::Stmt * buildMoveSingle( StatementNode * node ) {
        std::vector<ast::ptr<ast::Stmt>> list;
        buildMoveList( node, list );
        assertf( list.size() == 1, "CFA Internal Error: Extra/Missing Nodes" );
        return list.front().release();
}

static const ast::Stmt * buildMoveOptional( StatementNode * node ) {
        std::vector<ast::ptr<ast::Stmt>> list;
        buildMoveList( node, list );
        assertf( list.size() <= 1, "CFA Internal Error: Extra Nodes" );
        return list.empty() ? nullptr : list.front().release();
}

StatementNode::StatementNode( DeclarationNode * decl ) {
        assert( decl );
        DeclarationNode * agg = decl->extractAggregate();
        if ( agg ) {
                StatementNode * nextStmt = new StatementNode(
                        new ast::DeclStmt( decl->location, maybeBuild( decl ) ) );
                set_next( nextStmt );
                if ( decl->get_next() ) {
                        get_next()->set_next( new StatementNode( dynamic_cast< DeclarationNode * >(decl->get_next()) ) );
                        decl->set_next( 0 );
                } // if
        } else {
                if ( decl->get_next() ) {
                        set_next( new StatementNode( dynamic_cast< DeclarationNode * >( decl->get_next() ) ) );
                        decl->set_next( 0 );
                } // if
                agg = decl;
        } // if
        // Local copy to avoid accessing the pointer after it is moved from.
        CodeLocation declLocation = agg->location;
        stmt.reset( new ast::DeclStmt( declLocation, maybeMoveBuild( agg ) ) );
} // StatementNode::StatementNode

StatementNode * StatementNode::add_label(
                const CodeLocation & location,
                const std::string * name,
                DeclarationNode * attr ) {
        stmt->labels.emplace_back( location,
                *name,
                attr ? std::move( attr->attributes )
                        : std::vector<ast::ptr<ast::Attribute>>{} );
        delete attr;
        delete name;
        return this;
}

ClauseNode * ClauseNode::append_last_case( StatementNode * stmt ) {
        ClauseNode * prev = this;
        // find end of list and maintain previous pointer
        for ( ClauseNode * curr = prev; curr != nullptr; curr = (ClauseNode *)curr->get_next() ) {
                ClauseNode * node = strict_dynamic_cast< ClauseNode * >(curr);
                assert( dynamic_cast<ast::CaseClause *>( node->clause.get() ) );
                prev = curr;
        } // for
        ClauseNode * node = dynamic_cast< ClauseNode * >(prev);
        // convert from StatementNode list to Statement list
        std::vector<ast::ptr<ast::Stmt>> stmts;
        buildMoveList( stmt, stmts );
        // splice any new Statements to end of current Statements
        auto caseStmt = strict_dynamic_cast<ast::CaseClause *>( node->clause.get() );
        for ( auto const & newStmt : stmts ) {
                caseStmt->stmts.emplace_back( newStmt );
        }
        stmts.clear();
        return this;
} // ClauseNode::append_last_case

ast::Stmt * build_expr( CodeLocation const & location, ExpressionNode * ctl ) {
        if ( ast::Expr * e = maybeMoveBuild( ctl ) ) {
                return new ast::ExprStmt( location, e );
        } else {
                return new ast::NullStmt( location );
        }
} // build_expr

static ast::Expr * build_if_control( CondCtl * ctl,
                std::vector<ast::ptr<ast::Stmt>> & inits ) {
        assert( inits.empty() );
        if ( nullptr != ctl->init ) {
                buildMoveList( ctl->init, inits );
        } // if

        ast::Expr * cond = nullptr;
        if ( ctl->condition ) {
                // compare the provided condition against 0
                cond = notZeroExpr( maybeMoveBuild( ctl->condition ) );
        } else {
                for ( ast::ptr<ast::Stmt> & stmt : inits ) {
                        // build the && of all of the declared variables compared against 0
                        auto declStmt = stmt.strict_as<ast::DeclStmt>();
                        auto dwt = declStmt->decl.strict_as<ast::DeclWithType>();
                        ast::Expr * nze = notZeroExpr( new ast::VariableExpr( dwt->location, dwt ) );
                        cond = cond ? new ast::LogicalExpr( dwt->location, cond, nze, ast::AndExpr ) : nze;
                }
        }
        delete ctl;
        return cond;
} // build_if_control

ast::Stmt * build_if( const CodeLocation & location, CondCtl * ctl, StatementNode * then, StatementNode * else_ ) {
        std::vector<ast::ptr<ast::Stmt>> astinit;                                               // maybe empty
        ast::Expr * astcond = build_if_control( ctl, astinit ); // ctl deleted, cond/init set

        ast::Stmt const * astthen = buildMoveSingle( then );
        ast::Stmt const * astelse = buildMoveOptional( else_ );

        return new ast::IfStmt( location, astcond, astthen, astelse,
                std::move( astinit )
        );
} // build_if

ast::Stmt * build_switch( const CodeLocation & location, bool isSwitch, ExpressionNode * ctl, ClauseNode * stmt ) {
        std::vector<ast::ptr<ast::CaseClause>> aststmt;
        buildMoveList( stmt, aststmt );
        // If it is not a switch it is a choose statement.
        if ( ! isSwitch ) {
                for ( ast::ptr<ast::CaseClause> & stmt : aststmt ) {
                        // Code after "case" is the end of case list.
                        if ( !stmt->stmts.empty() ) {
                                auto mutStmt = ast::mutate( stmt.get() );
                                // I believe the stmts are actually always one block.
                                auto stmts = mutStmt->stmts.front().get_and_mutate();
                                auto block = strict_dynamic_cast<ast::CompoundStmt *>( stmts );
                                block->kids.push_back( new ast::BranchStmt( block->location,
                                        ast::BranchStmt::Break,
                                        ast::Label( block->location ) ) );
                                stmt = mutStmt;
                        } // if
                } // for
        } // if
        // aststmt.size() == 0 for switch (...) {}, i.e., no declaration or statements
        return new ast::SwitchStmt( location,
                maybeMoveBuild( ctl ), std::move( aststmt ) );
} // build_switch

ast::CaseClause * build_case( const CodeLocation & location, ExpressionNode * ctl ) {
        // stmt starts empty and then added to
        auto expr = maybeMoveBuild( ctl );
        return new ast::CaseClause( location, expr, {} );
} // build_case

ast::CaseClause * build_default( const CodeLocation & location ) {
        // stmt starts empty and then added to
        return new ast::CaseClause( location, nullptr, {} );
} // build_default

ast::Stmt * build_while( const CodeLocation & location, CondCtl * ctl, StatementNode * stmt, StatementNode * else_ ) {
        std::vector<ast::ptr<ast::Stmt>> astinit;                                               // maybe empty
        ast::Expr * astcond = build_if_control( ctl, astinit ); // ctl deleted, cond/init set

        return new ast::WhileDoStmt( location,
                astcond,
                buildMoveSingle( stmt ),
                buildMoveOptional( else_ ),
                std::move( astinit ),
                ast::While
        );
} // build_while

ast::Stmt * build_do_while( const CodeLocation & location, ExpressionNode * ctl, StatementNode * stmt, StatementNode * else_ ) {
        // do-while cannot have declarations in the contitional, so init is always empty
        return new ast::WhileDoStmt( location,
                notZeroExpr( maybeMoveBuild( ctl ) ),
                buildMoveSingle( stmt ),
                buildMoveOptional( else_ ),
                {},
                ast::DoWhile
        );
} // build_do_while

ast::Stmt * build_for( const CodeLocation & location, ForCtrl * forctl, StatementNode * stmt, StatementNode * else_ ) {
        std::vector<ast::ptr<ast::Stmt>> astinit;                                               // maybe empty
        buildMoveList( forctl->init, astinit );

        ast::Expr * astcond = nullptr;                                          // maybe empty
        astcond = notZeroExpr( maybeMoveBuild( forctl->condition ) );

        ast::Expr * astincr = nullptr;                                          // maybe empty
        astincr = maybeMoveBuild( forctl->change );
        delete forctl;

        return new ast::ForStmt( location,
                std::move( astinit ),
                astcond,
                astincr,
                buildMoveSingle( stmt ),
                buildMoveOptional( else_ )
        );
} // build_for

ast::Stmt * build_branch( const CodeLocation & location, ast::BranchStmt::Kind kind ) {
        return new ast::BranchStmt( location,
                kind,
                ast::Label( location )
        );
} // build_branch

ast::Stmt * build_branch( const CodeLocation & location, string * identifier, ast::BranchStmt::Kind kind ) {
        ast::Stmt * ret = new ast::BranchStmt( location,
                kind,
                ast::Label( location, *identifier )
        );
        delete identifier;                                                                      // allocated by lexer
        return ret;
} // build_branch

ast::Stmt * build_computedgoto( ExpressionNode * ctl ) {
        ast::Expr * expr = maybeMoveBuild( ctl );
        return new ast::BranchStmt( expr->location, expr );
} // build_computedgoto

ast::Stmt * build_return( const CodeLocation & location, ExpressionNode * ctl ) {
        std::vector<ast::ptr<ast::Expr>> exps;
        buildMoveList( ctl, exps );
        return new ast::ReturnStmt( location,
                exps.size() > 0 ? exps.back().release() : nullptr
        );
} // build_return

static ast::Stmt * build_throw_stmt(
                const CodeLocation & location,
                ExpressionNode * ctl,
                ast::ExceptionKind kind ) {
        std::vector<ast::ptr<ast::Expr>> exps;
        buildMoveList( ctl, exps );
        assertf( exps.size() < 2, "CFA internal error: leaking memory" );
        return new ast::ThrowStmt( location,
                kind,
                !exps.empty() ? exps.back().release() : nullptr,
                (ast::Expr *)nullptr
        );
}

ast::Stmt * build_throw( const CodeLocation & loc, ExpressionNode * ctl ) {
        return build_throw_stmt( loc, ctl, ast::Terminate );
} // build_throw

ast::Stmt * build_resume( const CodeLocation & loc, ExpressionNode * ctl ) {
        return build_throw_stmt( loc, ctl, ast::Resume );
} // build_resume

ast::Stmt * build_resume_at( ExpressionNode * ctl, ExpressionNode * target ) {
        (void)ctl;
        (void)target;
        assertf( false, "resume at (non-local throw) is not yet supported," );
} // build_resume_at

ast::Stmt * build_try( const CodeLocation & location, StatementNode * try_, ClauseNode * catch_, ClauseNode * finally_ ) {
        std::vector<ast::ptr<ast::CatchClause>> aststmt;
        buildMoveList( catch_, aststmt );
        ast::CompoundStmt * tryBlock = strict_dynamic_cast<ast::CompoundStmt *>( maybeMoveBuild( try_ ) );
        ast::FinallyClause * finallyBlock = nullptr;
        if ( finally_ ) {
                finallyBlock = dynamic_cast<ast::FinallyClause *>( finally_->clause.release() );
        }
        return new ast::TryStmt( location,
                tryBlock,
                std::move( aststmt ),
                finallyBlock
        );
} // build_try

ast::CatchClause * build_catch( const CodeLocation & location, ast::ExceptionKind kind, DeclarationNode * decl, ExpressionNode * cond, StatementNode * body ) {
        return new ast::CatchClause( location,
                kind,
                maybeMoveBuild( decl ),
                maybeMoveBuild( cond ),
                buildMoveSingle( body )
        );
} // build_catch

ast::FinallyClause * build_finally( const CodeLocation & location, StatementNode * stmt ) {
        return new ast::FinallyClause( location,
                strict_dynamic_cast<const ast::CompoundStmt *>(
                        buildMoveSingle( stmt )
                )
        );
} // build_finally

ast::SuspendStmt * build_suspend( const CodeLocation & location, StatementNode * then, ast::SuspendStmt::Kind kind ) {
        return new ast::SuspendStmt( location,
                strict_dynamic_cast<const ast::CompoundStmt *, nullptr>(
                        buildMoveOptional( then )
                ),
                kind
        );
} // build_suspend

ast::WaitForStmt * build_waitfor( const CodeLocation & location, ast::WaitForStmt * existing, ExpressionNode * when, ExpressionNode * targetExpr, StatementNode * stmt ) {
        auto clause = new ast::WaitForClause( location );
        clause->target = maybeBuild( targetExpr );
        clause->stmt = maybeMoveBuild( stmt );
        clause->when_cond = notZeroExpr( maybeMoveBuild( when ) );

        ExpressionNode * next = dynamic_cast<ExpressionNode *>( targetExpr->get_next() );
        targetExpr->set_next( nullptr );
        buildMoveList( next, clause->target_args );

        delete targetExpr;

        existing->clauses.insert( existing->clauses.begin(), clause );

        return existing;
} // build_waitfor

ast::WaitForStmt * build_waitfor_else( const CodeLocation & location, ast::WaitForStmt * existing, ExpressionNode * when, StatementNode * stmt ) {
        existing->else_stmt = maybeMoveBuild( stmt );
        existing->else_cond = notZeroExpr( maybeMoveBuild( when ) );

        (void)location;
        return existing;
} // build_waitfor_else

ast::WaitForStmt * build_waitfor_timeout( const CodeLocation & location, ast::WaitForStmt * existing, ExpressionNode * when, ExpressionNode * timeout, StatementNode * stmt ) {
        existing->timeout_time = maybeMoveBuild( timeout );
        existing->timeout_stmt = maybeMoveBuild( stmt );
        existing->timeout_cond = notZeroExpr( maybeMoveBuild( when ) );

        (void)location;
        return existing;
} // build_waitfor_timeout

ast::WaitUntilStmt::ClauseNode * build_waituntil_clause( const CodeLocation & loc, ExpressionNode * when, ExpressionNode * targetExpr, StatementNode * stmt ) {
    ast::WhenClause * clause = new ast::WhenClause( loc );
    clause->when_cond = notZeroExpr( maybeMoveBuild( when ) );
    clause->stmt = maybeMoveBuild( stmt );
    clause->target = maybeMoveBuild( targetExpr );
    return new ast::WaitUntilStmt::ClauseNode( clause );
}
ast::WaitUntilStmt::ClauseNode * build_waituntil_else( const CodeLocation & loc, ExpressionNode * when, StatementNode * stmt ) {
    ast::WhenClause * clause = new ast::WhenClause( loc );
    clause->when_cond = notZeroExpr( maybeMoveBuild( when ) );
    clause->stmt = maybeMoveBuild( stmt );
    return new ast::WaitUntilStmt::ClauseNode( ast::WaitUntilStmt::ClauseNode::Op::ELSE, clause );
}
ast::WaitUntilStmt::ClauseNode * build_waituntil_timeout( const CodeLocation & loc, ExpressionNode * when, ExpressionNode * timeout, StatementNode * stmt ) {
    ast::WhenClause * clause = new ast::WhenClause( loc );
    clause->when_cond = notZeroExpr( maybeMoveBuild( when ) );
    clause->stmt = maybeMoveBuild( stmt );
    clause->target = maybeMoveBuild( timeout );
    return new ast::WaitUntilStmt::ClauseNode( ast::WaitUntilStmt::ClauseNode::Op::TIMEOUT, clause );
}

ast::WaitUntilStmt * build_waituntil_stmt( const CodeLocation & loc, ast::WaitUntilStmt::ClauseNode * root ) {
    ast::WaitUntilStmt * retStmt = new ast::WaitUntilStmt( loc );
    retStmt->predicateTree = root;
    
    // iterative tree traversal
    std::vector<ast::WaitUntilStmt::ClauseNode *> nodeStack; // stack needed for iterative traversal
    ast::WaitUntilStmt::ClauseNode * currNode = nullptr;
    ast::WaitUntilStmt::ClauseNode * lastInternalNode = nullptr;
    ast::WaitUntilStmt::ClauseNode * cleanup = nullptr; // used to cleanup removed else/timeout
    nodeStack.push_back(root);

    do {
        currNode = nodeStack.back();
        nodeStack.pop_back(); // remove node since it will be processed

        switch (currNode->op) {
            case ast::WaitUntilStmt::ClauseNode::LEAF:
                retStmt->clauses.push_back(currNode->leaf);
                break;
            case ast::WaitUntilStmt::ClauseNode::ELSE:
                retStmt->else_stmt = currNode->leaf->stmt 
                    ? ast::deepCopy( currNode->leaf->stmt )
                    : nullptr;
                
                retStmt->else_cond = currNode->leaf->when_cond
                    ? ast::deepCopy( currNode->leaf->when_cond )
                    : nullptr;

                delete currNode->leaf;
                break;
            case ast::WaitUntilStmt::ClauseNode::TIMEOUT:
                retStmt->timeout_time = currNode->leaf->target 
                    ? ast::deepCopy( currNode->leaf->target )
                    : nullptr;
                retStmt->timeout_stmt = currNode->leaf->stmt
                    ? ast::deepCopy( currNode->leaf->stmt )
                    : nullptr;
                retStmt->timeout_cond = currNode->leaf->when_cond
                    ? ast::deepCopy( currNode->leaf->when_cond )
                    : nullptr;

                delete currNode->leaf;
                break;
            default:
                nodeStack.push_back( currNode->right ); // process right after left
                nodeStack.push_back( currNode->left );

                // Cut else/timeout out of the tree
                if ( currNode->op == ast::WaitUntilStmt::ClauseNode::LEFT_OR ) {
                    if ( lastInternalNode )
                        lastInternalNode->right = currNode->left;
                    else    // if not set then root is LEFT_OR 
                        retStmt->predicateTree = currNode->left;
    
                    currNode->left = nullptr;
                    cleanup = currNode;
                }
                
                lastInternalNode = currNode;
                break;
        }
    } while ( !nodeStack.empty() );

    if ( cleanup ) delete cleanup;

    return retStmt;
}

ast::Stmt * build_with( const CodeLocation & location, ExpressionNode * exprs, StatementNode * stmt ) {
        std::vector<ast::ptr<ast::Expr>> e;
        buildMoveList( exprs, e );
        ast::Stmt * s = maybeMoveBuild( stmt );
        return new ast::DeclStmt( location, new ast::WithStmt( location, std::move( e ), s ) );
} // build_with

ast::Stmt * build_compound( const CodeLocation & location, StatementNode * first ) {
        auto cs = new ast::CompoundStmt( location );
        buildMoveList( first, cs->kids );
        return cs;
} // build_compound

// A single statement in a control structure is always converted to a compound statement so subsequent generated code
// can be placed within this compound statement. Otherwise, code generation has to constantly check for a single
// statement and wrap it into a compound statement to insert additional code. Hence, all control structures have a
// conical form for code generation.
StatementNode * maybe_build_compound( const CodeLocation & location, StatementNode * first ) {
        // Optimization: if the control-structure statement is a compound statement, do not wrap it.
        // e.g., if (...) {...} do not wrap the existing compound statement.
        if ( !dynamic_cast<ast::CompoundStmt *>( first->stmt.get() ) ) { // unique_ptr
                return new StatementNode( build_compound( location, first ) );
        } // if
        return first;
} // maybe_build_compound

// Question
ast::Stmt * build_asm( const CodeLocation & location, bool is_volatile, ExpressionNode * instruction, ExpressionNode * output, ExpressionNode * input, ExpressionNode * clobber, LabelNode * gotolabels ) {
        std::vector<ast::ptr<ast::Expr>> out, in;
        std::vector<ast::ptr<ast::ConstantExpr>> clob;

        buildMoveList( output, out );
        buildMoveList( input, in );
        buildMoveList( clobber, clob );
        return new ast::AsmStmt( location,
                is_volatile,
                maybeMoveBuild( instruction ),
                std::move( out ),
                std::move( in ),
                std::move( clob ),
                gotolabels ? gotolabels->labels : std::vector<ast::Label>()
        );
} // build_asm

ast::Stmt * build_directive( const CodeLocation & location, string * directive ) {
        auto stmt = new ast::DirectiveStmt( location, *directive );
        delete directive;
        return stmt;
} // build_directive

ast::Stmt * build_mutex( const CodeLocation & location, ExpressionNode * exprs, StatementNode * stmt ) {
        std::vector<ast::ptr<ast::Expr>> expList;
        buildMoveList( exprs, expList );
        ast::Stmt * body = maybeMoveBuild( stmt );
        return new ast::MutexStmt( location, body, std::move( expList ) );
} // build_mutex

// Local Variables: //
// tab-width: 4 //
// mode: c++ //
// compile-command: "make install" //
// End: //