/*      $NetBSD: make.c,v 1.275 2026/04/06 17:13:54 rillig Exp $        */

/*
 * Copyright (c) 1988, 1989, 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Copyright (c) 1989 by Berkeley Softworks
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Examination of targets and their suitability for creation.
 *
 * Interface:
 *      Make_MakeParallel
 *                      Make the targets in parallel mode.
 *
 *      Make_Update     After a target is made, update all its parents.
 *                      Perform various bookkeeping chores like the updating
 *                      of the youngestChild field of the parent, filling
 *                      of the IMPSRC variable, etc. Place the parent on the
 *                      toBeMade queue if it should be.
 *
 *      GNode_UpdateYoungestChild
 *                      Update the node's youngestChild field based on the
 *                      child's modification time.
 *
 *      GNode_SetLocalVars
 *                      Set up the various local variables for a
 *                      target, including the .ALLSRC variable, making
 *                      sure that any variable that needs to exist
 *                      at the very least has the empty value.
 *
 *      GNode_IsOODate  Determine if a target is out-of-date.
 *
 *      Make_HandleUse  See if a child is a .USE node for a parent
 *                      and perform the .USE actions if so.
 *
 *      Make_ExpandUse  Expand .USE nodes
 */

#include "make.h"
#include "dir.h"
#include "job.h"
#ifdef USE_META
# include "meta.h"
#endif

/*      "@(#)make.c     8.1 (Berkeley) 6/6/93"  */
MAKE_RCSID("$NetBSD: make.c,v 1.275 2026/04/06 17:13:54 rillig Exp $");

/* Sequence # to detect recursion. */
static unsigned checked_seqno = 1;

/*
 * The current fringe of the graph.
 * These are nodes which await examination by MakeOODate.
 * It is added to by Make_Update and subtracted from by MakeStartJobs
 */
static GNodeList toBeMade = LST_INIT;


void
debug_printf(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        vfprintf(opts.debug_file, fmt, ap);
        va_end(ap);
}

char *
GNodeType_ToString(GNodeType type)
{
        Buffer buf;

        Buf_Init(&buf);
#define ADD(flag) Buf_AddFlag(&buf, (type & (flag)) != OP_NONE, #flag)
        ADD(OP_DEPENDS);
        ADD(OP_FORCE);
        ADD(OP_DOUBLEDEP);
        ADD(OP_OPTIONAL);
        ADD(OP_USE);
        ADD(OP_EXEC);
        ADD(OP_IGNORE);
        ADD(OP_PRECIOUS);
        ADD(OP_SILENT);
        ADD(OP_MAKE);
        ADD(OP_JOIN);
        ADD(OP_MADE);
        ADD(OP_SPECIAL);
        ADD(OP_USEBEFORE);
        ADD(OP_INVISIBLE);
        ADD(OP_NOTMAIN);
        ADD(OP_PHONY);
        ADD(OP_NOPATH);
        ADD(OP_WAIT);
        ADD(OP_NOMETA);
        ADD(OP_META);
        ADD(OP_NOMETA_CMP);
        ADD(OP_SUBMAKE);
        ADD(OP_TRANSFORM);
        ADD(OP_MEMBER);
        ADD(OP_LIB);
        ADD(OP_ARCHV);
        ADD(OP_HAS_COMMANDS);
        ADD(OP_SAVE_CMDS);
        ADD(OP_DEPS_FOUND);
        ADD(OP_MARK);
#undef ADD
        if (buf.len == 0)
                Buf_AddStr(&buf, "none");
        return Buf_DoneData(&buf);
}

static char *
GNodeFlags_ToString(GNodeFlags flags)
{
        Buffer buf;

        Buf_Init(&buf);
        Buf_AddFlag(&buf, flags.remake, "REMAKE");
        Buf_AddFlag(&buf, flags.childMade, "CHILDMADE");
        Buf_AddFlag(&buf, flags.force, "FORCE");
        Buf_AddFlag(&buf, flags.doneWait, "DONE_WAIT");
        Buf_AddFlag(&buf, flags.doneOrder, "DONE_ORDER");
        Buf_AddFlag(&buf, flags.fromDepend, "FROM_DEPEND");
        Buf_AddFlag(&buf, flags.doneAllsrc, "DONE_ALLSRC");
        Buf_AddFlag(&buf, flags.doneSubmake, "DONE_SUBMAKE");
        Buf_AddFlag(&buf, flags.cycle, "CYCLE");
        Buf_AddFlag(&buf, flags.doneCycle, "DONECYCLE");
        if (buf.len == 0)
                Buf_AddStr(&buf, "none");
        return Buf_DoneData(&buf);
}

void
GNode_FprintDetails(FILE *f, const char *prefix, const GNode *gn,
                    const char *suffix)
{
        char *type = GNodeType_ToString(gn->type);
        char *flags = GNodeFlags_ToString(gn->flags);

        fprintf(f, "%s%s, type %s, flags %s%s",
            prefix, GNodeMade_Name(gn->made), type, flags, suffix);
        free(type);
        free(flags);
}

bool
GNode_ShouldExecute(GNode *gn)
{
        return !(gn->type & OP_MAKE
            ? opts.noRecursiveExecute
            : opts.noExecute);
}

/* Update the youngest child of the node, according to the given child. */
void
GNode_UpdateYoungestChild(GNode *gn, GNode *cgn)
{
        if (gn->youngestChild == NULL || cgn->mtime > gn->youngestChild->mtime)
                gn->youngestChild = cgn;
}

static bool
IsOODateRegular(GNode *gn)
{
        /* These rules are inherited from the original Make. */

        if (gn->youngestChild != NULL) {
                if (gn->mtime < gn->youngestChild->mtime) {
                        DEBUG1(MAKE, "modified before source \"%s\"...",
                            GNode_Path(gn->youngestChild));
                        return true;
                }
                return false;
        }

        if (gn->mtime == 0 && !(gn->type & OP_OPTIONAL)) {
                DEBUG0(MAKE, "nonexistent and no sources...");
                return true;
        }

        if (gn->type & OP_DOUBLEDEP) {
                DEBUG0(MAKE, ":: operator and no sources...");
                return true;
        }

        return false;
}

/*
 * See if the node is out of date with respect to its sources.
 *
 * Used by Make_MakeParallel when deciding which nodes to place on the
 * toBeMade queue initially and by Make_Update to screen out .USE and
 * .EXEC nodes. In the latter case, however, any other sort of node
 * must be considered out-of-date since at least one of its children
 * will have been recreated.
 *
 * The mtime field of the node and the youngestChild field of its parents
 * may be changed.
 */
bool
GNode_IsOODate(GNode *gn)
{
        bool oodate;

        /*
         * Certain types of targets needn't even be sought as their datedness
         * doesn't depend on their modification time...
         */
        if (!(gn->type & (OP_JOIN | OP_USE | OP_USEBEFORE | OP_EXEC))) {
                Dir_UpdateMTime(gn, true);
                if (DEBUG(MAKE)) {
                        if (gn->mtime != 0)
                                debug_printf("modified %s...",
                                    Targ_FmtTime(gn->mtime));
                        else
                                debug_printf("nonexistent...");
                }
        }

        /*
         * A target is remade in one of the following circumstances:
         *
         *      its modification time is smaller than that of its youngest
         *      child and it would actually be run (has commands or is not
         *      GNode_IsTarget)
         *
         *      it's the object of a force operator
         *
         *      it has no children, was on the lhs of an operator and doesn't
         *      exist already.
         *
         * Libraries are only considered out-of-date if the archive module
         * says they are.
         *
         * These weird rules are brought to you by Backward-Compatibility
         * and the strange people who wrote 'Make'.
         */
        if (gn->type & (OP_USE | OP_USEBEFORE)) {
                /*
                 * If the node is a USE node it is *never* out of date
                 * no matter *what*.
                 */
                DEBUG0(MAKE, ".USE node...");
                oodate = false;
        } else if ((gn->type & OP_LIB) && (gn->mtime == 0 || Arch_IsLib(gn))) {
                DEBUG0(MAKE, "library...");

                /*
                 * always out of date if no children and :: target
                 * or nonexistent.
                 */
                oodate = gn->mtime == 0 || Arch_LibOODate(gn) ||
                    (gn->youngestChild == NULL && (gn->type & OP_DOUBLEDEP));
        } else if (gn->type & OP_JOIN) {
                /*
                 * A target with the .JOIN attribute is only considered
                 * out-of-date if any of its children was out-of-date.
                 */
                DEBUG0(MAKE, ".JOIN node...");
                DEBUG1(MAKE, "source %smade...",
                    gn->flags.childMade ? "" : "not ");
                oodate = gn->flags.childMade;
        } else if (gn->type & (OP_FORCE | OP_EXEC | OP_PHONY)) {
                /*
                 * A node which is the object of the force (!) operator or
                 * which has the .EXEC attribute is always considered
                 * out-of-date.
                 */
                if (DEBUG(MAKE)) {
                        if (gn->type & OP_FORCE)
                                debug_printf("! operator...");
                        else if (gn->type & OP_PHONY)
                                debug_printf(".PHONY node...");
                        else
                                debug_printf(".EXEC node...");
                }
                oodate = true;
        } else if (IsOODateRegular(gn)) {
                oodate = true;
        } else {
                /*
                 * When a nonexistent child with no sources
                 * (such as a typically used FORCE source) has been made and
                 * the target of the child (usually a directory) has the same
                 * timestamp as the timestamp just given to the nonexistent
                 * child after it was considered made.
                 */
                if (DEBUG(MAKE)) {
                        if (gn->flags.force)
                                debug_printf("non existing child...");
                }
                oodate = gn->flags.force;
        }

#ifdef USE_META
        if (useMeta)
                oodate = meta_oodate(gn, oodate);
#endif

        /*
         * If the target isn't out-of-date, the parents need to know its
         * modification time. Note that targets that appear to be out-of-date
         * but aren't, because they have no commands and are GNode_IsTarget,
         * have their mtime stay below their children's mtime to keep parents
         * from thinking they're out-of-date.
         */
        if (!oodate) {
                GNodeListNode *ln;
                for (ln = gn->parents.first; ln != NULL; ln = ln->next)
                        GNode_UpdateYoungestChild(ln->datum, gn);
        }

        return oodate;
}

static void
PretendAllChildrenAreMade(GNode *pgn)
{
        GNodeListNode *ln;

        for (ln = pgn->children.first; ln != NULL; ln = ln->next) {
                GNode *cgn = ln->datum;

                /* This may also update cgn->path. */
                Dir_UpdateMTime(cgn, false);
                GNode_UpdateYoungestChild(pgn, cgn);
                pgn->unmade--;
        }
}

/*
 * Called by Make_MakeParallel and SuffApplyTransform on the downward pass to
 * handle .USE and transformation nodes, by copying the child node's commands,
 * type flags and children to the parent node.
 *
 * A .USE node is much like an explicit transformation rule, except its
 * commands are always added to the target node, even if the target already
 * has commands.
 *
 * Input:
 *      cgn             The source node, which is either a .USE/.USEBEFORE
 *                      node or a transformation node (OP_TRANSFORM).
 *      pgn             The target node
 */
void
Make_HandleUse(GNode *cgn, GNode *pgn)
{
        GNodeListNode *ln;      /* An element in the children list */

#ifdef DEBUG_SRC
        if (!(cgn->type & (OP_USE | OP_USEBEFORE | OP_TRANSFORM))) {
                debug_printf("Make_HandleUse: called for plain node %s\n",
                    cgn->name);
                /* XXX: debug mode should not affect control flow */
                return;
        }
#endif

        if ((cgn->type & (OP_USE | OP_USEBEFORE)) ||
            Lst_IsEmpty(&pgn->commands)) {
                if (cgn->type & OP_USEBEFORE) {
                        /* .USEBEFORE */
                        Lst_PrependAll(&pgn->commands, &cgn->commands);
                } else {
                        /* .USE, or target has no commands */
                        Lst_AppendAll(&pgn->commands, &cgn->commands);
                }
        }

        for (ln = cgn->children.first; ln != NULL; ln = ln->next) {
                GNode *gn = ln->datum;

                /*
                 * Expand variables in the .USE node's name
                 * and save the unexpanded form.
                 * We don't need to do this for commands.
                 * They get expanded properly when we execute.
                 */
                if (gn->uname == NULL)
                        gn->uname = gn->name;
                else
                        free(gn->name);
                gn->name = Var_Subst(gn->uname, pgn, VARE_EVAL);
                /* TODO: handle errors */
                if (gn->uname != NULL && strcmp(gn->name, gn->uname) != 0) {
                        /* See if we have a target for this node. */
                        GNode *tgn = Targ_FindNode(gn->name);
                        if (tgn != NULL)
                                gn = tgn;
                }

                Lst_Append(&pgn->children, gn);
                Lst_Append(&gn->parents, pgn);
                pgn->unmade++;
        }

        pgn->type |=
            cgn->type & (unsigned)~(OP_OPMASK | OP_USE | OP_USEBEFORE | OP_TRANSFORM);
}

/*
 * Used by Make_MakeParallel on the downward pass to handle .USE nodes. Should
 * be called before the children are enqueued to be looked at by MakeAddChild.
 *
 * For a .USE child, the commands, type flags and children are copied to the
 * parent node, and since the relation to the .USE node is then no longer
 * needed, that relation is removed.
 *
 * Input:
 *      cgn             the child, which may be a .USE node
 *      pgn             the current parent
 */
static void
MakeHandleUse(GNode *cgn, GNode *pgn, GNodeListNode *ln)
{
        bool unmarked;

        unmarked = !(cgn->type & OP_MARK);
        cgn->type |= OP_MARK;

        if (!(cgn->type & (OP_USE | OP_USEBEFORE)))
                return;

        if (unmarked)
                Make_HandleUse(cgn, pgn);

        Lst_Remove(&pgn->children, ln);
        pgn->unmade--;
}

static void
HandleUseNodes(GNode *gn)
{
        GNodeListNode *ln, *nln;
        for (ln = gn->children.first; ln != NULL; ln = nln) {
                nln = ln->next;
                MakeHandleUse(ln->datum, gn, ln);
        }
}


/*
 * Check the modification time of a gnode, and update it if necessary.
 * Return 0 if the gnode does not exist, or its filesystem time if it does.
 */
time_t
Make_Recheck(GNode *gn)
{
        time_t mtime;

        Dir_UpdateMTime(gn, true);
        mtime = gn->mtime;

#ifndef RECHECK
        /*
         * We can't re-stat the thing, but we can at least take care of rules
         * where a target depends on a source that actually creates the
         * target, but only if it has changed, e.g.
         *
         * parse.h : parse.o
         *
         * parse.o : parse.y
         *              yacc -d parse.y
         *              cc -c y.tab.c
         *              mv y.tab.o parse.o
         *              cmp -s y.tab.h parse.h || mv y.tab.h parse.h
         *
         * In this case, if the definitions produced by yacc haven't changed
         * from before, parse.h won't have been updated and gn->mtime will
         * reflect the current modification time for parse.h. This is
         * something of a kludge, I admit, but it's a useful one.
         *
         * XXX: People like to use a rule like "FRC:" to force things that
         * depend on FRC to be made, so we have to check for gn->children
         * being empty as well.
         */
        if (!Lst_IsEmpty(gn->commands) || Lst_IsEmpty(gn->children))
                gn->mtime = now;
#else
        /*
         * This is what Make does and it's actually a good thing, as it
         * allows rules like
         *
         *      cmp -s y.tab.h parse.h || cp y.tab.h parse.h
         *
         * to function as intended. Unfortunately, thanks to the stateless
         * nature of NFS (by which I mean the loose coupling of two clients
         * using the same file from a common server), there are times when
         * the modification time of a file created on a remote machine
         * will not be modified before the local stat() implied by the
         * Dir_UpdateMTime occurs, thus leading us to believe that the file
         * is unchanged, wreaking havoc with files that depend on this one.
         *
         * I have decided it is better to make too much than to make too
         * little, so this stuff is commented out unless you're sure it's ok.
         * -- ardeb 1/12/88
         */
        /*
         * Christos, 4/9/92: If we are saving commands, pretend that
         * the target is made now. Otherwise archives with '...' rules
         * don't work!
         */
        if (!GNode_ShouldExecute(gn) || (gn->type & OP_SAVE_CMDS) ||
            (mtime == 0 && !(gn->type & OP_WAIT))) {
                DEBUG2(MAKE, " recheck(%s): update time from %s to now\n",
                    gn->name,
                    gn->mtime == 0 ? "nonexistent" : Targ_FmtTime(gn->mtime));
                gn->mtime = now;
        } else {
                DEBUG2(MAKE, " recheck(%s): current update time: %s\n",
                    gn->name, Targ_FmtTime(gn->mtime));
        }
#endif

        /*
         * XXX: The returned mtime may differ from gn->mtime. Intentionally?
         */
        return mtime;
}

/*
 * Set the .PREFIX and .IMPSRC variables for all the implied parents
 * of this node.
 */
static void
UpdateImplicitParentsVars(GNode *cgn, const char *cname)
{
        GNodeListNode *ln;
        const char *cpref = GNode_VarPrefix(cgn);

        for (ln = cgn->implicitParents.first; ln != NULL; ln = ln->next) {
                GNode *pgn = ln->datum;
                if (pgn->flags.remake) {
                        Var_Set(pgn, IMPSRC, cname);
                        if (cpref != NULL)
                                Var_Set(pgn, PREFIX, cpref);
                }
        }
}

/* See if a .ORDER rule stops us from building this node. */
static bool
IsWaitingForOrder(GNode *gn)
{
        GNodeListNode *ln;

        for (ln = gn->order_pred.first; ln != NULL; ln = ln->next) {
                GNode *ogn = ln->datum;

                if (GNode_IsDone(ogn) || !ogn->flags.remake)
                        continue;

                DEBUG2(MAKE,
                    "IsWaitingForOrder: Waiting for .ORDER node \"%s%s\"\n",
                    ogn->name, ogn->cohort_num);
                return true;
        }
        return false;
}

static bool MakeBuildChild(GNode *, GNodeListNode *);

static void
ScheduleOrderSuccessors(GNode *gn)
{
        GNodeListNode *toBeMadeNext = toBeMade.first;
        GNodeListNode *ln;

        for (ln = gn->order_succ.first; ln != NULL; ln = ln->next) {
                GNode *succ = ln->datum;

                if (succ->made == DEFERRED &&
                    !MakeBuildChild(succ, toBeMadeNext))
                        succ->flags.doneOrder = true;
        }
}

/*
 * Perform update on the parents of a node. Used by JobFinish once
 * a node has been dealt with and by MakeStartJobs if it finds an
 * up-to-date node.
 *
 * The unmade field of pgn is decremented and pgn may be placed on
 * the toBeMade queue if this field becomes 0.
 *
 * If the child was made, the parent's flag CHILDMADE field will be
 * set true.
 *
 * If the child is not up-to-date and still does not exist,
 * set the FORCE flag on the parents.
 *
 * If the child wasn't made, the youngestChild field of the parent will be
 * altered if the child's mtime is big enough.
 *
 * Finally, if the child is the implied source for the parent, the
 * parent's IMPSRC variable is set appropriately.
 */
void
Make_Update(GNode *cgn)
{
        const char *cname;      /* the child's name */
        time_t mtime = -1;
        GNodeList *parents;
        GNodeListNode *ln;
        GNode *centurion;

        /* It is save to re-examine any nodes again */
        checked_seqno++;

        cname = GNode_VarTarget(cgn);

        DEBUG2(MAKE, "Make_Update: %s%s\n", cgn->name, cgn->cohort_num);

        /*
         * If the child was actually made, see what its modification time is
         * now -- some rules won't actually update the file. If the file
         * still doesn't exist, make its mtime now.
         */
        if (cgn->made != UPTODATE)
                mtime = Make_Recheck(cgn);

        /*
         * If this is a `::' node, we must consult its first instance
         * which is where all parents are linked.
         */
        if ((centurion = cgn->centurion) != NULL) {
                if (!Lst_IsEmpty(&cgn->parents))
                        Punt("%s%s: cohort has parents", cgn->name,
                            cgn->cohort_num);
                centurion->unmade_cohorts--;
                if (centurion->unmade_cohorts < 0)
                        Error("Graph cycles through centurion %s",
                            centurion->name);
        } else {
                centurion = cgn;
        }
        parents = &centurion->parents;

        /* If this was a .ORDER node, schedule the RHS */
        ScheduleOrderSuccessors(centurion);

        /* Now mark all the parents as having one less unmade child */
        for (ln = parents->first; ln != NULL; ln = ln->next) {
                GNode *pgn = ln->datum;

                if (DEBUG(MAKE)) {
                        debug_printf("inspect parent %s%s: ", pgn->name,
                            pgn->cohort_num);
                        GNode_FprintDetails(opts.debug_file, "", pgn, "");
                        debug_printf(", unmade %d ", pgn->unmade - 1);
                }

                if (!pgn->flags.remake) {
                        /* This parent isn't needed */
                        DEBUG0(MAKE, "- not needed\n");
                        continue;
                }
                if (mtime == 0 && !(cgn->type & OP_WAIT))
                        pgn->flags.force = true;

                /*
                 * If the parent has the .MADE attribute, its timestamp got
                 * updated to that of its newest child, and its unmade
                 * child count got set to zero in Make_ExpandUse().
                 * However other things might cause us to build one of its
                 * children - and so we mustn't do any processing here when
                 * the child build finishes.
                 */
                if (pgn->type & OP_MADE) {
                        DEBUG0(MAKE, "- .MADE\n");
                        continue;
                }

                if (!(cgn->type & (OP_EXEC | OP_USE | OP_USEBEFORE))) {
                        if (cgn->made == MADE)
                                pgn->flags.childMade = true;
                        GNode_UpdateYoungestChild(pgn, cgn);
                }

                /*
                 * A parent must wait for the completion of all instances
                 * of a `::' dependency.
                 */
                if (centurion->unmade_cohorts != 0 ||
                    !GNode_IsDone(centurion)) {
                        DEBUG2(MAKE,
                            "- centurion made %d, %d unmade cohorts\n",
                            centurion->made, centurion->unmade_cohorts);
                        continue;
                }

                /* One more child of this parent is now made */
                pgn->unmade--;
                if (pgn->unmade < 0) {
                        if (DEBUG(MAKE)) {
                                debug_printf("Graph cycles through %s%s\n",
                                    pgn->name, pgn->cohort_num);
                                Targ_PrintGraph(2);
                        }
                        Error("Graph cycles through %s%s", pgn->name,
                            pgn->cohort_num);
                }

                /*
                 * We must always rescan the parents of .WAIT and .ORDER
                 * nodes.
                 */
                if (pgn->unmade != 0 && !(centurion->type & OP_WAIT)
                    && !centurion->flags.doneOrder) {
                        DEBUG0(MAKE, "- unmade children\n");
                        continue;
                }
                if (pgn->made != DEFERRED) {
                        /*
                         * Either this parent is on a different branch of
                         * the tree, or it on the RHS of a .WAIT directive
                         * or it is already on the toBeMade list.
                         */
                        DEBUG0(MAKE, "- not deferred\n");
                        continue;
                }

                if (IsWaitingForOrder(pgn))
                        continue;

                if (DEBUG(MAKE)) {
                        debug_printf("- %s%s made, schedule %s%s (made %d)\n",
                            cgn->name, cgn->cohort_num,
                            pgn->name, pgn->cohort_num, pgn->made);
                        Targ_PrintNode(pgn, 2);
                }
                /* Ok, we can schedule the parent again */
                pgn->made = REQUESTED;
                Lst_Enqueue(&toBeMade, pgn);
        }

        UpdateImplicitParentsVars(cgn, cname);
}

static void
UnmarkChildren(GNode *gn)
{
        GNodeListNode *ln;

        for (ln = gn->children.first; ln != NULL; ln = ln->next) {
                GNode *child = ln->datum;
                child->type &= (unsigned)~OP_MARK;
        }
}

/*
 * Add a child's name to the ALLSRC and OODATE variables of the given
 * node, but only if it has not been given the .EXEC, .USE or .INVISIBLE
 * attributes. .EXEC and .USE children are very rarely going to be files,
 * so...
 *
 * If the child is a .JOIN node, its ALLSRC is propagated to the parent.
 *
 * A child is added to the OODATE variable if its modification time is
 * later than that of its parent, as defined by Make, except if the
 * parent is a .JOIN node. In that case, it is only added to the OODATE
 * variable if it was actually made (since .JOIN nodes don't have
 * modification times, the comparison is rather unfair...)..
 *
 * Input:
 *      cgn             The child to add
 *      pgn             The parent to whose ALLSRC variable it should
 *                      be added
 */
static void
MakeAddAllSrc(GNode *cgn, GNode *pgn)
{
        const char *child, *allsrc;

        if (cgn->type & OP_MARK)
                return;
        cgn->type |= OP_MARK;

        if (cgn->type & (OP_EXEC | OP_USE | OP_USEBEFORE | OP_INVISIBLE))
                return;

        if (cgn->type & OP_ARCHV)
                child = GNode_VarMember(cgn);
        else
                child = GNode_Path(cgn);

        if (cgn->type & OP_JOIN)
                allsrc = GNode_VarAllsrc(cgn);
        else
                allsrc = child;

        if (allsrc != NULL)
                Var_Append(pgn, ALLSRC, allsrc);

        if (pgn->type & OP_JOIN) {
                if (cgn->made == MADE)
                        Var_Append(pgn, OODATE, child);

        } else if (pgn->mtime < cgn->mtime ||
                   (cgn->mtime >= now && cgn->made == MADE)) {
                /*
                 * It goes in the OODATE variable if the parent is
                 * younger than the child or if the child has been
                 * modified more recently than the start of the make.
                 * This is to keep pmake from getting confused if
                 * something else updates the parent after the make
                 * starts (shouldn't happen, I know, but sometimes it
                 * does). In such a case, if we've updated the child,
                 * the parent is likely to have a modification time
                 * later than that of the child and anything that
                 * relies on the OODATE variable will be hosed.
                 *
                 * XXX: This will cause all made children to go in
                 * the OODATE variable, even if they're not touched,
                 * if RECHECK isn't defined, since cgn->mtime is set
                 * to now in Make_Update. According to some people,
                 * this is good...
                 */
                Var_Append(pgn, OODATE, child);
        }
}

/*
 * Set up the ALLSRC and OODATE variables. Sad to say, it must be
 * done separately, rather than while traversing the graph. This is
 * because Make defined OODATE to contain all sources whose modification
 * times were later than that of the target, *not* those sources that
 * were out-of-date. Since in both compatibility and native modes,
 * the modification time of the parent isn't found until the child
 * has been dealt with, we have to wait until now to fill in the
 * variable. As for ALLSRC, the ordering is important and not
 * guaranteed when in native mode, so it must be set here, too.
 *
 * If the node is a .JOIN node, its TARGET variable will be set to
 * match its ALLSRC variable.
 */
void
GNode_SetLocalVars(GNode *gn)
{
        GNodeListNode *ln;

        if (gn->flags.doneAllsrc)
                return;

        UnmarkChildren(gn);
        for (ln = gn->children.first; ln != NULL; ln = ln->next)
                MakeAddAllSrc(ln->datum, gn);

        if (!Var_Exists(gn, OODATE))
                Var_Set(gn, OODATE, "");
        if (!Var_Exists(gn, ALLSRC))
                Var_Set(gn, ALLSRC, "");

        if (gn->type & OP_JOIN)
                Var_Set(gn, TARGET, GNode_VarAllsrc(gn));
        gn->flags.doneAllsrc = true;
}

static void
ScheduleRandomly(GNode *gn)
{
        GNodeListNode *ln;
        size_t i, n;

        n = 0;
        for (ln = toBeMade.first; ln != NULL; ln = ln->next)
                n++;
        i = n > 0 ? (size_t)random() % (n + 1) : 0;

        if (i == 0) {
                Lst_Append(&toBeMade, gn);
                return;
        }
        i--;

        for (ln = toBeMade.first; i > 0; ln = ln->next)
                i--;
        Lst_InsertBefore(&toBeMade, ln, gn);
}

static bool
MakeBuildChild(GNode *cn, GNodeListNode *toBeMadeNext)
{

        if (DEBUG(MAKE)) {
                debug_printf("MakeBuildChild: inspect %s%s, ",
                    cn->name, cn->cohort_num);
                GNode_FprintDetails(opts.debug_file, "", cn, "\n");
        }
        if (GNode_IsReady(cn))
                return false;

        /* If this node is on the RHS of a .ORDER, check LHSs. */
        if (IsWaitingForOrder(cn)) {
                /*
                 * Can't build this (or anything else in this child list) yet
                 */
                cn->made = DEFERRED;
                return false;   /* but keep looking */
        }

        DEBUG2(MAKE, "MakeBuildChild: schedule %s%s\n",
            cn->name, cn->cohort_num);

        cn->made = REQUESTED;
        if (opts.randomizeTargets && !(cn->type & OP_WAIT))
                ScheduleRandomly(cn);
        else if (toBeMadeNext == NULL)
                Lst_Append(&toBeMade, cn);
        else
                Lst_InsertBefore(&toBeMade, toBeMadeNext, cn);

        if (cn->unmade_cohorts != 0) {
                ListNode *ln;

                for (ln = cn->cohorts.first; ln != NULL; ln = ln->next)
                        if (MakeBuildChild(ln->datum, toBeMadeNext))
                                break;
        }

        /*
         * If this node is a .WAIT node with unmade children
         * then don't add the next sibling.
         */
        return cn->type & OP_WAIT && cn->unmade > 0;
}

static void
MakeChildren(GNode *gn)
{
        GNodeListNode *toBeMadeNext = toBeMade.first;
        GNodeListNode *ln;

        for (ln = gn->children.first; ln != NULL; ln = ln->next)
                if (MakeBuildChild(ln->datum, toBeMadeNext))
                        break;
}

/*
 * Start as many jobs as possible, taking them from the toBeMade queue.
 *
 * If the -q option was given, no job will be started,
 * but as soon as an out-of-date target is found, this function
 * returns true. In all other cases, this function returns false.
 */
static bool
MakeStartJobs(void)
{
        GNode *gn;
        bool have_token = false;

        while (!Lst_IsEmpty(&toBeMade)) {
                /*
                 * Get token now to avoid cycling job-list when we only
                 * have 1 token
                 */
                if (!have_token && !TokenPool_Take())
                        break;
                have_token = true;

                gn = Lst_Dequeue(&toBeMade);
                DEBUG2(MAKE, "Examining %s%s...\n", gn->name, gn->cohort_num);

                if (gn->made != REQUESTED) {
                        debug_printf("internal error: made = %s\n",
                            GNodeMade_Name(gn->made));
                        Targ_PrintNode(gn, 2);
                        Targ_PrintNodes(&toBeMade, 2);
                        Targ_PrintGraph(3);
                        abort();
                }

                if (gn->checked_seqno == checked_seqno) {
                        /*
                         * We've already looked at this node since a job
                         * finished...
                         */
                        DEBUG2(MAKE, "already checked %s%s\n",
                            gn->name, gn->cohort_num);
                        gn->made = DEFERRED;
                        continue;
                }
                gn->checked_seqno = checked_seqno;

                if (gn->unmade != 0) {
                        gn->made = DEFERRED;
                        MakeChildren(gn);
                        DEBUG2(MAKE, "deferred %s%s\n",
                            gn->name, gn->cohort_num);
                        continue;
                }

                gn->made = BEINGMADE;
                if (GNode_IsOODate(gn)) {
                        DEBUG0(MAKE, "out-of-date\n");
                        if (opts.query)
                                return strcmp(gn->name, ".MAIN") != 0;
                        GNode_SetLocalVars(gn);
                        Job_Make(gn);
                        have_token = false;
                } else {
                        DEBUG0(MAKE, "up-to-date\n");
                        gn->made = UPTODATE;
                        if (gn->type & OP_JOIN) {
                                /*
                                 * Even for an up-to-date .JOIN node, we
                                 * need it to have its local variables so
                                 * references to it get the correct value
                                 * for .TARGET when building up the local
                                 * variables of its parent(s)...
                                 */
                                GNode_SetLocalVars(gn);
                        }
                        Make_Update(gn);
                }
        }

        if (have_token)
                TokenPool_Return();

        return false;
}

/* Print the status of a .ORDER node. */
static void
MakePrintStatusOrderNode(GNode *ogn, GNode *gn)
{
        if (!GNode_IsWaitingFor(ogn))
                return;

        printf("    `%s%s' has .ORDER dependency on %s%s ",
            gn->name, gn->cohort_num, ogn->name, ogn->cohort_num);
        GNode_FprintDetails(stdout, "(", ogn, ")\n");

        if (DEBUG(MAKE) && opts.debug_file != stdout) {
                debug_printf("    `%s%s' has .ORDER dependency on %s%s ",
                    gn->name, gn->cohort_num, ogn->name, ogn->cohort_num);
                GNode_FprintDetails(opts.debug_file, "(", ogn, ")\n");
        }
}

static void
MakePrintStatusOrder(GNode *gn)
{
        GNodeListNode *ln;
        for (ln = gn->order_pred.first; ln != NULL; ln = ln->next)
                MakePrintStatusOrderNode(ln->datum, gn);
}

static void MakePrintStatusList(GNodeList *, int *);

/*
 * Print the status of a top-level node, viz. it being up-to-date already
 * or not created due to an error in a lower level.
 */
static bool
MakePrintStatus(GNode *gn, int *errors)
{
        if (gn->flags.doneCycle) {
                /*
                 * We've completely processed this node before, don't do
                 * it again.
                 */
                return false;
        }

        if (gn->unmade == 0) {
                gn->flags.doneCycle = true;
                switch (gn->made) {
                case UPTODATE:
                        printf("`%s%s' is up to date.\n", gn->name,
                            gn->cohort_num);
                        break;
                case MADE:
                        break;
                case UNMADE:
                case DEFERRED:
                case REQUESTED:
                case BEINGMADE:
                        (*errors)++;
                        printf("`%s%s' was not built", gn->name,
                            gn->cohort_num);
                        GNode_FprintDetails(stdout, " (", gn, ")!\n");
                        if (DEBUG(MAKE) && opts.debug_file != stdout) {
                                debug_printf("`%s%s' was not built", gn->name,
                                    gn->cohort_num);
                                GNode_FprintDetails(opts.debug_file, " (", gn,
                                    ")!\n");
                        }
                        /* Most likely problem is actually caused by .ORDER */
                        MakePrintStatusOrder(gn);
                        break;
                default:
                        /* Errors - already counted */
                        printf("`%s%s' not remade because of errors.\n",
                            gn->name, gn->cohort_num);
                        if (DEBUG(MAKE) && opts.debug_file != stdout)
                                debug_printf(
                                    "`%s%s' not remade because of errors.\n",
                                    gn->name, gn->cohort_num);
                        break;
                }
                return false;
        }

        DEBUG3(MAKE, "MakePrintStatus: %s%s has %d unmade children\n",
            gn->name, gn->cohort_num, gn->unmade);
        /*
         * If printing cycles and came to one that has unmade children,
         * print out the cycle by recursing on its children.
         */
        if (!gn->flags.cycle) {
                /* First time we've seen this node, check all children */
                gn->flags.cycle = true;
                MakePrintStatusList(&gn->children, errors);
                /* Mark that this node needn't be processed again */
                gn->flags.doneCycle = true;
                return false;
        }

        /* Only output the error once per node */
        gn->flags.doneCycle = true;
        Error("Graph cycles through `%s%s'", gn->name, gn->cohort_num);
        if ((*errors)++ > 100)
                /* Abandon the whole error report */
                return true;

        /* Reporting for our children will give the rest of the loop */
        MakePrintStatusList(&gn->children, errors);
        return false;
}

static void
MakePrintStatusList(GNodeList *gnodes, int *errors)
{
        GNodeListNode *ln;

        for (ln = gnodes->first; ln != NULL; ln = ln->next)
                if (MakePrintStatus(ln->datum, errors))
                        break;
}

static void
ExamineLater(GNodeList *examine, GNodeList *toBeExamined)
{
        GNodeListNode *ln;

        for (ln = toBeExamined->first; ln != NULL; ln = ln->next) {
                GNode *gn = ln->datum;

                if (gn->flags.remake)
                        continue;
                if (gn->type & (OP_USE | OP_USEBEFORE))
                        continue;

                DEBUG2(MAKE, "ExamineLater: need to examine \"%s%s\"\n",
                    gn->name, gn->cohort_num);
                Lst_Enqueue(examine, gn);
        }
}

/* Expand .USE nodes and create a new targets list. */
void
Make_ExpandUse(GNodeList *targets)
{
        GNodeList examine = LST_INIT;   /* Queue of targets to examine */
        Lst_AppendAll(&examine, targets);

        /*
         * Make an initial downward pass over the graph, marking nodes to
         * be made as we go down.
         *
         * We call Suff_FindDeps to find where a node is and to get some
         * children for it if it has none and also has no commands. If the
         * node is a leaf, we stick it on the toBeMade queue to be looked
         * at in a minute, otherwise we add its children to our queue and
         * go on.
         */
        while (!Lst_IsEmpty(&examine)) {
                GNode *gn = Lst_Dequeue(&examine);

                if (gn->flags.remake)
                        continue;
                gn->flags.remake = true;

                DEBUG2(MAKE, "Make_ExpandUse: examine %s%s\n",
                    gn->name, gn->cohort_num);

                if (gn->type & OP_DOUBLEDEP)
                        Lst_PrependAll(&examine, &gn->cohorts);

                /*
                 * Apply any .USE rules before looking for implicit
                 * dependencies to make sure everything has commands that
                 * should.
                 *
                 * Make sure that the TARGET is set, so that we can make
                 * expansions.
                 */
                if (gn->type & OP_ARCHV) {
                        char *eoa = strchr(gn->name, '(');
                        char *eon = strchr(gn->name, ')');
                        if (eoa == NULL || eon == NULL)
                                continue;
                        *eoa = '\0';
                        *eon = '\0';
                        Var_Set(gn, MEMBER, eoa + 1);
                        Var_Set(gn, ARCHIVE, gn->name);
                        *eoa = '(';
                        *eon = ')';
                }

                Dir_UpdateMTime(gn, false);
                Var_Set(gn, TARGET, GNode_Path(gn));
                UnmarkChildren(gn);
                HandleUseNodes(gn);

                if (!(gn->type & OP_MADE))
                        Suff_FindDeps(gn);
                else {
                        PretendAllChildrenAreMade(gn);
                        if (gn->unmade != 0) {
                                printf(
                                    "Warning: "
                                    "%s%s still has %d unmade children\n",
                                    gn->name, gn->cohort_num, gn->unmade);
                        }
                }

                if (gn->unmade != 0)
                        ExamineLater(&examine, &gn->children);
        }

        Lst_Done(&examine);
}

/* Make the .WAIT node depend on the previous children */
static void
AddWaitDependency(GNodeListNode *prevWaitNode, GNode *waitNode)
{
        GNodeListNode *ln;

        for (ln = prevWaitNode; ln->datum != waitNode; ln = ln->next) {
                GNode *gn = ln->datum;
                DEBUG3(MAKE, ".WAIT: add dependency \"%s: %s%s\"\n",
                    waitNode->name, gn->name, gn->cohort_num);
                Lst_Append(&waitNode->children, gn);
                Lst_Append(&gn->parents, waitNode);
                waitNode->unmade++;
        }
}

/* Convert .WAIT nodes into dependencies. */
static void
Make_ProcessWait(GNodeList *targets)
{
        GNode *pgn;             /* 'parent' node we are examining */
        GNodeList examine;

        /*
         * We need all the nodes to have a common parent in order for the
         * .WAIT and .ORDER scheduling to work.
         * Perhaps this should be done earlier...
         */

        pgn = GNode_New(".MAIN");
        pgn->flags.remake = true;
        pgn->type = OP_PHONY | OP_DEPENDS;
        /* Get it displayed in the diag dumps */
        Lst_Prepend(Targ_List(), pgn);

        {
                GNodeListNode *ln;
                for (ln = targets->first; ln != NULL; ln = ln->next) {
                        GNode *cgn = ln->datum;

                        Lst_Append(&pgn->children, cgn);
                        Lst_Append(&cgn->parents, pgn);
                        pgn->unmade++;
                }
        }

        /* Start building with the 'dummy' .MAIN' node */
        MakeBuildChild(pgn, NULL);

        Lst_Init(&examine);
        Lst_Append(&examine, pgn);

        while (!Lst_IsEmpty(&examine)) {
                GNodeListNode *waitNode, *ln;

                pgn = Lst_Dequeue(&examine);

                /* We only want to process each child-list once */
                if (pgn->flags.doneWait)
                        continue;
                pgn->flags.doneWait = true;
                DEBUG1(MAKE, "Make_ProcessWait: examine %s\n", pgn->name);

                if (pgn->type & OP_DOUBLEDEP)
                        Lst_PrependAll(&examine, &pgn->cohorts);

                waitNode = pgn->children.first;
                for (ln = pgn->children.first; ln != NULL; ln = ln->next) {
                        GNode *cgn = ln->datum;
                        if (cgn->type & OP_WAIT) {
                                AddWaitDependency(waitNode, cgn);
                                waitNode = ln;
                        } else
                                Lst_Append(&examine, cgn);
                }
        }

        Lst_Done(&examine);
}

bool
Make_MakeParallel(GNodeList *targets)
{
        int errors;             /* Number of errors the Job module reports */

        Lst_Init(&toBeMade);

        Make_ExpandUse(targets);
        Make_ProcessWait(targets);

        if (DEBUG(MAKE)) {
                debug_printf("#***# full graph\n");
                Targ_PrintGraph(1);
        }

        if (opts.query)
                return MakeStartJobs();

        (void)MakeStartJobs();
        while (!Lst_IsEmpty(&toBeMade) || jobTokensRunning > 0) {
                Job_CatchOutput();
                (void)MakeStartJobs();
        }

        errors = Job_MakeDotEnd();

        DEBUG1(MAKE, "done: errors %d\n", errors);
        if (errors == 0) {
                MakePrintStatusList(targets, &errors);
                if (DEBUG(MAKE)) {
                        debug_printf("done: errors %d\n", errors);
                        if (errors > 0)
                                Targ_PrintGraph(4);
                }
        }
        return errors > 0;
}