[dragonfly.git] / usr.bin / make / suff.c

/*
 * Copyright (c) 1988, 1989, 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 * 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.
 *
 * @(#)suff.c   8.4 (Berkeley) 3/21/94
 * $FreeBSD: src/usr.bin/make/suff.c,v 1.12.2.2 2004/06/10 13:07:53 ru Exp $
 * $DragonFly: src/usr.bin/make/suff.c,v 1.16 2004/12/16 22:20:12 okumoto Exp $
 */

/*-
 * suff.c --
 *      Functions to maintain suffix lists and find implicit dependents
 *      using suffix transformation rules
 *
 * Interface:
 *      Suff_Init               Initialize all things to do with suffixes.
 *
 *      Suff_End                Cleanup the module
 *
 *      Suff_DoPaths            This function is used to make life easier
 *                              when searching for a file according to its
 *                              suffix. It takes the global search path,
 *                              as defined using the .PATH: target, and appends
 *                              its directories to the path of each of the
 *                              defined suffixes, as specified using
 *                              .PATH<suffix>: targets. In addition, all
 *                              directories given for suffixes labeled as
 *                              include files or libraries, using the .INCLUDES
 *                              or .LIBS targets, are played with using
 *                              Dir_MakeFlags to create the .INCLUDES and
 *                              .LIBS global variables.
 *
 *      Suff_ClearSuffixes      Clear out all the suffixes and defined
 *                              transformations.
 *
 *      Suff_IsTransform        Return TRUE if the passed string is the lhs
 *                              of a transformation rule.
 *
 *      Suff_AddSuffix          Add the passed string as another known suffix.
 *
 *      Suff_GetPath            Return the search path for the given suffix.
 *
 *      Suff_AddInclude         Mark the given suffix as denoting an include
 *                              file.
 *
 *      Suff_AddLib             Mark the given suffix as denoting a library.
 *
 *      Suff_AddTransform       Add another transformation to the suffix
 *                              graph. Returns  GNode suitable for framing, I
 *                              mean, tacking commands, attributes, etc. on.
 *
 *      Suff_SetNull            Define the suffix to consider the suffix of
 *                              any file that doesn't have a known one.
 *
 *      Suff_FindDeps           Find implicit sources for and the location of
 *                              a target based on its suffix. Returns the
 *                              bottom-most node added to the graph or NULL
 *                              if the target had no implicit sources.
 */

#include          <stdio.h>
#include          "make.h"
#include          "hash.h"
#include          "dir.h"

static Lst       sufflist;      /* Lst of suffixes */
static Lst       suffClean;     /* Lst of suffixes to be cleaned */
static Lst       srclist;       /* Lst of sources */
static Lst       transforms;    /* Lst of transformation rules */

static int        sNum = 0;     /* Counter for assigning suffix numbers */

/*
 * Structure describing an individual suffix.
 */
typedef struct _Suff {
    char         *name;         /* The suffix itself */
    int          nameLen;       /* Length of the suffix */
    short        flags;         /* Type of suffix */
#define SUFF_INCLUDE      0x01      /* One which is #include'd */
#define SUFF_LIBRARY      0x02      /* One which contains a library */
#define SUFF_NULL         0x04      /* The empty suffix */
    Lst          searchPath;    /* The path along which files of this suffix
                                 * may be found */
    int          sNum;          /* The suffix number */
    int          refCount;      /* Reference count of list membership */
    Lst          parents;       /* Suffixes we have a transformation to */
    Lst          children;      /* Suffixes we have a transformation from */
    Lst          ref;           /* List of lists this suffix is referenced */
} Suff;

/*
 * Structure used in the search for implied sources.
 */
typedef struct _Src {
    char            *file;      /* The file to look for */
    char            *pref;      /* Prefix from which file was formed */
    Suff            *suff;      /* The suffix on the file */
    struct _Src     *parent;    /* The Src for which this is a source */
    GNode           *node;      /* The node describing the file */
    int             children;   /* Count of existing children (so we don't free
                                 * this thing too early or never nuke it) */
#ifdef DEBUG_SRC
    Lst             cp;         /* Debug; children list */
#endif
} Src;

/*
 * A structure for passing more than one argument to the Lst-library-invoked
 * function...
 */
typedef struct {
    Lst            l;
    Src            *s;
} LstSrc;

static Suff         *suffNull;  /* The NULL suffix for this run */
static Suff         *emptySuff; /* The empty suffix required for POSIX
                                 * single-suffix transformation rules */


static char *SuffStrIsPrefix(char *, char *);
static char *SuffSuffIsSuffix(Suff *, char *);
static int SuffSuffIsSuffixP(void *, void *);
static int SuffSuffHasNameP(void *, void *);
static int SuffSuffIsPrefix(void *, void *);
static int SuffGNHasNameP(void *, void *);
static void SuffFree(void *);
static void SuffInsert(Lst, Suff *);
static void SuffRemove(Lst, Suff *);
static Boolean SuffParseTransform(char *, Suff **, Suff **);
static int SuffRebuildGraph(void *, void *);
static int SuffAddSrc(void *, void *);
static int SuffRemoveSrc(Lst);
static void SuffAddLevel(Lst, Src *);
static Src *SuffFindThem(Lst, Lst);
static Src *SuffFindCmds(Src *, Lst);
static int SuffExpandChildren(void *, void *);
static Boolean SuffApplyTransform(GNode *, GNode *, Suff *, Suff *);
static void SuffFindDeps(GNode *, Lst);
static void SuffFindArchiveDeps(GNode *, Lst);
static void SuffFindNormalDeps(GNode *, Lst);
static int SuffPrintName(void *, void *);
static int SuffPrintSuff(void *, void *);
static int SuffPrintTrans(void *, void *);

        /*************** Lst Predicates ****************/
/*-
 *-----------------------------------------------------------------------
 * SuffStrIsPrefix  --
 *      See if pref is a prefix of str.
 *
 * Results:
 *      NULL if it ain't, pointer to character in str after prefix if so
 *
 * Side Effects:
 *      None
 *-----------------------------------------------------------------------
 */
static char    *
SuffStrIsPrefix(char *pref, char *str)
{

    while (*str && *pref == *str) {
        pref++;
        str++;
    }

    return (*pref ? NULL : str);
}

/*-
 *-----------------------------------------------------------------------
 * SuffSuffIsSuffix  --
 *      See if suff is a suffix of str. Str should point to THE END of the
 *      string to check. (THE END == the null byte)
 *
 * Results:
 *      NULL if it ain't, pointer to character in str before suffix if
 *      it is.
 *
 * Side Effects:
 *      None
 *-----------------------------------------------------------------------
 */
static char *
SuffSuffIsSuffix(Suff *s, char *str)
{
    char           *p1;         /* Pointer into suffix name */
    char           *p2;         /* Pointer into string being examined */

    p1 = s->name + s->nameLen;
    p2 = str;

    while (p1 >= s->name && *p1 == *p2) {
        p1--;
        p2--;
    }

    return (p1 == s->name - 1 ? p2 : NULL);
}

/*-
 *-----------------------------------------------------------------------
 * SuffSuffIsSuffixP --
 *      Predicate form of SuffSuffIsSuffix. Passed as the callback function
 *      to Lst_Find.
 *
 * Results:
 *      0 if the suffix is the one desired, non-zero if not.
 *
 * Side Effects:
 *      None.
 *
 *-----------------------------------------------------------------------
 */
static int
SuffSuffIsSuffixP(void *s, void *str)
{

    return (!SuffSuffIsSuffix(s, str));
}

/*-
 *-----------------------------------------------------------------------
 * SuffSuffHasNameP --
 *      Callback procedure for finding a suffix based on its name. Used by
 *      Suff_GetPath.
 *
 * Results:
 *      0 if the suffix is of the given name. non-zero otherwise.
 *
 * Side Effects:
 *      None
 *-----------------------------------------------------------------------
 */
static int
SuffSuffHasNameP(void *s, void *sname)
{

    return (strcmp(sname, ((Suff *)s)->name));
}

/*-
 *-----------------------------------------------------------------------
 * SuffSuffIsPrefix  --
 *      See if the suffix described by s is a prefix of the string. Care
 *      must be taken when using this to search for transformations and
 *      what-not, since there could well be two suffixes, one of which
 *      is a prefix of the other...
 *
 * Results:
 *      0 if s is a prefix of str. non-zero otherwise
 *
 * Side Effects:
 *      None
 *-----------------------------------------------------------------------
 */
static int
SuffSuffIsPrefix(void *s, void *str)
{

    return (SuffStrIsPrefix(((Suff *)s)->name, str) == NULL ? 1 : 0);
}

/*-
 *-----------------------------------------------------------------------
 * SuffGNHasNameP  --
 *      See if the graph node has the desired name
 *
 * Results:
 *      0 if it does. non-zero if it doesn't
 *
 * Side Effects:
 *      None
 *-----------------------------------------------------------------------
 */
static int
SuffGNHasNameP(void *gn, void *name)
{

    return (strcmp(name, ((GNode *)gn)->name));
}

            /*********** Maintenance Functions ************/

/*-
 *-----------------------------------------------------------------------
 * SuffFree  --
 *      Free up all memory associated with the given suffix structure.
 *
 * Results:
 *      none
 *
 * Side Effects:
 *      the suffix entry is detroyed
 *-----------------------------------------------------------------------
 */
static void
SuffFree(void *sp)
{
    Suff *s = sp;

    if (s == suffNull)
        suffNull = NULL;

    if (s == emptySuff)
        emptySuff = NULL;

    Lst_Destroy(s->ref, NOFREE);
    Lst_Destroy(s->children, NOFREE);
    Lst_Destroy(s->parents, NOFREE);
    Lst_Destroy(s->searchPath, Dir_Destroy);

    free(s->name);
    free(s);
}

/*-
 *-----------------------------------------------------------------------
 * SuffRemove  --
 *      Remove the suffix into the list
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      The reference count for the suffix is decremented
 *-----------------------------------------------------------------------
 */
static void
SuffRemove(Lst l, Suff *s)
{
    LstNode ln = Lst_Member(l, s);

    if (ln != NULL) {
        Lst_Remove(l, ln);
        s->refCount--;
    }
}

/*-
 *-----------------------------------------------------------------------
 * SuffInsert  --
 *      Insert the suffix into the list keeping the list ordered by suffix
 *      numbers.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      The reference count of the suffix is incremented
 *-----------------------------------------------------------------------
 */
static void
SuffInsert(Lst l, Suff *s)
{
    LstNode       ln;           /* current element in l we're examining */
    Suff          *s2 = NULL;   /* the suffix descriptor in this element */

    if (Lst_Open(l) == FAILURE) {
        return;
    }
    while ((ln = Lst_Next(l)) != NULL) {
        s2 = Lst_Datum(ln);
        if (s2->sNum >= s->sNum) {
            break;
        }
    }
    if (s2 == NULL) {
            DEBUGF(SUFF, ("inserting an empty list?..."));
    }

    Lst_Close(l);
    DEBUGF(SUFF, ("inserting %s(%d)...", s->name, s->sNum));
    if (ln == NULL) {
        DEBUGF(SUFF, ("at end of list\n"));
        Lst_AtEnd (l, s);
        s->refCount++;
        Lst_AtEnd(s->ref, l);
    } else if (s2->sNum != s->sNum) {
        DEBUGF(SUFF, ("before %s(%d)\n", s2->name, s2->sNum));
        Lst_Insert(l, ln, s);
        s->refCount++;
        Lst_AtEnd(s->ref, l);
    } else {
        DEBUGF(SUFF, ("already there\n"));
    }
}

/*-
 *-----------------------------------------------------------------------
 * Suff_ClearSuffixes --
 *      This is gross. Nuke the list of suffixes but keep all transformation
 *      rules around. The transformation graph is destroyed in this process,
 *      but we leave the list of rules so when a new graph is formed the rules
 *      will remain.
 *      This function is called from the parse module when a
 *      .SUFFIXES:\n line is encountered.
 *
 * Results:
 *      none
 *
 * Side Effects:
 *      the sufflist and its graph nodes are destroyed
 *-----------------------------------------------------------------------
 */
void
Suff_ClearSuffixes(void)
{

    Lst_Concat(suffClean, sufflist, LST_CONCLINK);
    sufflist = Lst_Init(FALSE);
    sNum = 1;
    suffNull = emptySuff;
    /*
     * Clear suffNull's children list (the other suffixes are built new, but
     * suffNull is used as is).
     * NOFREE is used because all suffixes are are on the suffClean list.
     * suffNull should not have parents.
     */
    Lst_Destroy(suffNull->children, NOFREE);
    suffNull->children = Lst_Init(FALSE);
}

/*-
 *-----------------------------------------------------------------------
 * SuffParseTransform --
 *      Parse a transformation string to find its two component suffixes.
 *
 * Results:
 *      TRUE if the string is a valid transformation and FALSE otherwise.
 *
 * Side Effects:
 *      The passed pointers are overwritten.
 *
 *-----------------------------------------------------------------------
 */
static Boolean
SuffParseTransform(char *str, Suff **srcPtr, Suff **targPtr)
{
    LstNode             srcLn;      /* element in suffix list of trans source*/
    Suff                *src;       /* Source of transformation */
    LstNode             targLn;     /* element in suffix list of trans target*/
    char                *str2;      /* Extra pointer (maybe target suffix) */
    LstNode             singleLn;   /* element in suffix list of any suffix
                                     * that exactly matches str */
    Suff                *single = NULL;/* Source of possible transformation to
                                     * null suffix */

    srcLn = NULL;
    singleLn = NULL;

    /*
     * Loop looking first for a suffix that matches the start of the
     * string and then for one that exactly matches the rest of it. If
     * we can find two that meet these criteria, we've successfully
     * parsed the string.
     */
    for (;;) {
        if (srcLn == NULL) {
            srcLn = Lst_Find(sufflist, str, SuffSuffIsPrefix);
        } else {
            srcLn = Lst_FindFrom(sufflist, Lst_Succ(srcLn), str,
                                  SuffSuffIsPrefix);
        }
        if (srcLn == NULL) {
            /*
             * Ran out of source suffixes -- no such rule
             */
            if (singleLn != NULL) {
                /*
                 * Not so fast Mr. Smith! There was a suffix that encompassed
                 * the entire string, so we assume it was a transformation
                 * to the null suffix (thank you POSIX). We still prefer to
                 * find a double rule over a singleton, hence we leave this
                 * check until the end.
                 *
                 * XXX: Use emptySuff over suffNull?
                 */
                *srcPtr = single;
                *targPtr = suffNull;
                return (TRUE);
            }
            return (FALSE);
        }
        src = Lst_Datum (srcLn);
        str2 = str + src->nameLen;
        if (*str2 == '\0') {
            single = src;
            singleLn = srcLn;
        } else {
            targLn = Lst_Find(sufflist, str2, SuffSuffHasNameP);
            if (targLn != NULL) {
                *srcPtr = src;
                *targPtr = Lst_Datum(targLn);
                return (TRUE);
            }
        }
    }
}

/*-
 *-----------------------------------------------------------------------
 * Suff_IsTransform  --
 *      Return TRUE if the given string is a transformation rule
 *
 *
 * Results:
 *      TRUE if the string is a concatenation of two known suffixes.
 *      FALSE otherwise
 *
 * Side Effects:
 *      None
 *-----------------------------------------------------------------------
 */
Boolean
Suff_IsTransform(char *str)
{
    Suff          *src, *targ;

    return (SuffParseTransform(str, &src, &targ));
}

/*-
 *-----------------------------------------------------------------------
 * Suff_AddTransform --
 *      Add the transformation rule described by the line to the
 *      list of rules and place the transformation itself in the graph
 *
 * Results:
 *      The node created for the transformation in the transforms list
 *
 * Side Effects:
 *      The node is placed on the end of the transforms Lst and links are
 *      made between the two suffixes mentioned in the target name
 *-----------------------------------------------------------------------
 */
GNode *
Suff_AddTransform(char *line)
{
    GNode         *gn;          /* GNode of transformation rule */
    Suff          *s,           /* source suffix */
                  *t;           /* target suffix */
    LstNode       ln;           /* Node for existing transformation */

    ln = Lst_Find(transforms, line, SuffGNHasNameP);
    if (ln == NULL) {
        /*
         * Make a new graph node for the transformation. It will be filled in
         * by the Parse module.
         */
        gn = Targ_NewGN(line);
        Lst_AtEnd(transforms, gn);
    } else {
        /*
         * New specification for transformation rule. Just nuke the old list
         * of commands so they can be filled in again... We don't actually
         * free the commands themselves, because a given command can be
         * attached to several different transformations.
         */
        gn = Lst_Datum(ln);
        Lst_Destroy(gn->commands, NOFREE);
        Lst_Destroy(gn->children, NOFREE);
        gn->commands = Lst_Init(FALSE);
        gn->children = Lst_Init(FALSE);
    }

    gn->type = OP_TRANSFORM;

    SuffParseTransform(line, &s, &t);

    /*
     * link the two together in the proper relationship and order
     */
    DEBUGF(SUFF, ("defining transformation from `%s' to `%s'\n",
           s->name, t->name));
    SuffInsert(t->children, s);
    SuffInsert(s->parents, t);

    return (gn);
}

/*-
 *-----------------------------------------------------------------------
 * Suff_EndTransform --
 *      Handle the finish of a transformation definition, removing the
 *      transformation from the graph if it has neither commands nor
 *      sources. This is a callback procedure for the Parse module via
 *      Lst_ForEach
 *
 * Results:
 *      === 0
 *
 * Side Effects:
 *      If the node has no commands or children, the children and parents
 *      lists of the affected suffices are altered.
 *
 *-----------------------------------------------------------------------
 */
int
Suff_EndTransform(void *gnp, void *dummy __unused)
{
    GNode *gn = (GNode *)gnp;

    if ((gn->type & OP_TRANSFORM) && Lst_IsEmpty(gn->commands) &&
        Lst_IsEmpty(gn->children))
    {
        Suff    *s, *t;

        /*
         * SuffParseTransform() may fail for special rules which are not
         * actual transformation rules (e.g., .DEFAULT).
         */
        if (!SuffParseTransform(gn->name, &s, &t))
                return (0);

        DEBUGF(SUFF, ("deleting transformation from `%s' to `%s'\n",
               s->name, t->name));

        /*
         * Remove the source from the target's children list. We check for a
         * NULL return to handle a beanhead saying something like
         *  .c.o .c.o:
         *
         * We'll be called twice when the next target is seen, but .c and .o
         * are only linked once...
         */
        SuffRemove(t->children, s);

        /*
         * Remove the target from the source's parents list
         */
        SuffRemove(s->parents, t);
    } else if (gn->type & OP_TRANSFORM) {
        DEBUGF(SUFF, ("transformation %s complete\n", gn->name));
    }

    return (0);
}

/*-
 *-----------------------------------------------------------------------
 * SuffRebuildGraph --
 *      Called from Suff_AddSuffix via Lst_ForEach to search through the
 *      list of existing transformation rules and rebuild the transformation
 *      graph when it has been destroyed by Suff_ClearSuffixes. If the
 *      given rule is a transformation involving this suffix and another,
 *      existing suffix, the proper relationship is established between
 *      the two.
 *
 * Results:
 *      Always 0.
 *
 * Side Effects:
 *      The appropriate links will be made between this suffix and
 *      others if transformation rules exist for it.
 *
 *-----------------------------------------------------------------------
 */
static int
SuffRebuildGraph(void *transformp, void *sp)
{
    GNode       *transform = transformp;
    Suff        *s = sp;
    char        *cp;
    LstNode     ln;
    Suff        *s2 = NULL;

    /*
     * First see if it is a transformation from this suffix.
     */
    cp = SuffStrIsPrefix(s->name, transform->name);
    if (cp != (char *)NULL) {
        if (cp[0] == '\0')  /* null rule */
            s2 = suffNull;
        else {
            ln = Lst_Find(sufflist, cp, SuffSuffHasNameP);
            if (ln != NULL)
                s2 = Lst_Datum(ln);
        }
        if (s2 != NULL) {
            /*
             * Found target. Link in and return, since it can't be anything
             * else.
             */
            SuffInsert(s2->children, s);
            SuffInsert(s->parents, s2);
            return (0);
        }
    }

    /*
     * Not from, maybe to?
     */
    cp = SuffSuffIsSuffix(s, transform->name + strlen(transform->name));
    if (cp != NULL) {
        /*
         * Null-terminate the source suffix in order to find it.
         */
        cp[1] = '\0';
        ln = Lst_Find(sufflist, transform->name, SuffSuffHasNameP);
        /*
         * Replace the start of the target suffix
         */
        cp[1] = s->name[0];
        if (ln != NULL) {
            /*
             * Found it -- establish the proper relationship
             */
            s2 = Lst_Datum(ln);
            SuffInsert(s->children, s2);
            SuffInsert(s2->parents, s);
        }
    }
    return (0);
}

/*-
 *-----------------------------------------------------------------------
 * Suff_AddSuffix --
 *      Add the suffix in string to the end of the list of known suffixes.
 *      Should we restructure the suffix graph? Make doesn't...
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      A GNode is created for the suffix and a Suff structure is created and
 *      added to the suffixes list unless the suffix was already known.
 *-----------------------------------------------------------------------
 */
void
Suff_AddSuffix(char *str)
{
    Suff          *s;       /* new suffix descriptor */
    LstNode       ln;

    ln = Lst_Find(sufflist, str, SuffSuffHasNameP);
    if (ln == NULL) {
        s = emalloc(sizeof(Suff));

        s->name = estrdup(str);
        s->nameLen = strlen (s->name);
        s->searchPath = Lst_Init(FALSE);
        s->children = Lst_Init(FALSE);
        s->parents = Lst_Init(FALSE);
        s->ref = Lst_Init(FALSE);
        s->sNum = sNum++;
        s->flags = 0;
        s->refCount = 0;

        Lst_AtEnd(sufflist, s);

        /*
         * Look for any existing transformations from or to this suffix.
         * XXX: Only do this after a Suff_ClearSuffixes?
         */
        Lst_ForEach(transforms, SuffRebuildGraph, s);
    }
}

/*-
 *-----------------------------------------------------------------------
 * Suff_GetPath --
 *      Return the search path for the given suffix, if it's defined.
 *
 * Results:
 *      The searchPath for the desired suffix or NULL if the suffix isn't
 *      defined.
 *
 * Side Effects:
 *      None
 *-----------------------------------------------------------------------
 */
Lst
Suff_GetPath(char *sname)
{
    LstNode       ln;
    Suff          *s;

    ln = Lst_Find(sufflist, sname, SuffSuffHasNameP);
    if (ln == NULL) {
        return (NULL);
    } else {
        s = Lst_Datum(ln);
        return (s->searchPath);
    }
}

/*-
 *-----------------------------------------------------------------------
 * Suff_DoPaths --
 *      Extend the search paths for all suffixes to include the default
 *      search path.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      The searchPath field of all the suffixes is extended by the
 *      directories in dirSearchPath. If paths were specified for the
 *      ".h" suffix, the directories are stuffed into a global variable
 *      called ".INCLUDES" with each directory preceded by a -I. The same
 *      is done for the ".a" suffix, except the variable is called
 *      ".LIBS" and the flag is -L.
 *-----------------------------------------------------------------------
 */
void
Suff_DoPaths(void)
{
    Suff                *s;
    LstNode             ln;
    char                *ptr;
    Lst                 inIncludes; /* Cumulative .INCLUDES path */
    Lst                 inLibs;     /* Cumulative .LIBS path */

    if (Lst_Open(sufflist) == FAILURE) {
        return;
    }

    inIncludes = Lst_Init(FALSE);
    inLibs = Lst_Init(FALSE);

    while ((ln = Lst_Next(sufflist)) != NULL) {
        s = Lst_Datum(ln);
        if (!Lst_IsEmpty(s->searchPath)) {
#ifdef INCLUDES
            if (s->flags & SUFF_INCLUDE) {
                Dir_Concat(inIncludes, s->searchPath);
            }
#endif /* INCLUDES */
#ifdef LIBRARIES
            if (s->flags & SUFF_LIBRARY) {
                Dir_Concat(inLibs, s->searchPath);
            }
#endif /* LIBRARIES */
            Dir_Concat(s->searchPath, dirSearchPath);
        } else {
            Lst_Destroy(s->searchPath, Dir_Destroy);
            s->searchPath = Lst_Duplicate(dirSearchPath, Dir_CopyDir);
        }
    }

    Var_Set(".INCLUDES", ptr = Dir_MakeFlags("-I", inIncludes), VAR_GLOBAL);
    free(ptr);
    Var_Set(".LIBS", ptr = Dir_MakeFlags("-L", inLibs), VAR_GLOBAL);
    free(ptr);

    Lst_Destroy(inIncludes, Dir_Destroy);
    Lst_Destroy(inLibs, Dir_Destroy);

    Lst_Close(sufflist);
}

/*-
 *-----------------------------------------------------------------------
 * Suff_AddInclude --
 *      Add the given suffix as a type of file which gets included.
 *      Called from the parse module when a .INCLUDES line is parsed.
 *      The suffix must have already been defined.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      The SUFF_INCLUDE bit is set in the suffix's flags field
 *
 *-----------------------------------------------------------------------
 */
void
Suff_AddInclude(char *sname)
{
    LstNode       ln;
    Suff          *s;

    ln = Lst_Find(sufflist, sname, SuffSuffHasNameP);
    if (ln != NULL) {
        s = Lst_Datum(ln);
        s->flags |= SUFF_INCLUDE;
    }
}

/*-
 *-----------------------------------------------------------------------
 * Suff_AddLib --
 *      Add the given suffix as a type of file which is a library.
 *      Called from the parse module when parsing a .LIBS line. The
 *      suffix must have been defined via .SUFFIXES before this is
 *      called.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      The SUFF_LIBRARY bit is set in the suffix's flags field
 *
 *-----------------------------------------------------------------------
 */
void
Suff_AddLib(char *sname)
{
    LstNode       ln;
    Suff          *s;

    ln = Lst_Find(sufflist, sname, SuffSuffHasNameP);
    if (ln != NULL) {
        s = Lst_Datum(ln);
        s->flags |= SUFF_LIBRARY;
    }
}

          /********** Implicit Source Search Functions *********/

/*-
 *-----------------------------------------------------------------------
 * SuffAddSrc  --
 *      Add a suffix as a Src structure to the given list with its parent
 *      being the given Src structure. If the suffix is the null suffix,
 *      the prefix is used unaltered as the file name in the Src structure.
 *
 * Results:
 *      always returns 0
 *
 * Side Effects:
 *      A Src structure is created and tacked onto the end of the list
 *-----------------------------------------------------------------------
 */
static int
SuffAddSrc(void *sp, void *lsp)
{
    Suff        *s = sp;
    LstSrc      *ls = lsp;
    Src         *s2;        /* new Src structure */
    Src         *targ;      /* Target structure */

    targ = ls->s;

    if ((s->flags & SUFF_NULL) && (*s->name != '\0')) {
        /*
         * If the suffix has been marked as the NULL suffix, also create a Src
         * structure for a file with no suffix attached. Two birds, and all
         * that...
         */
        s2 = emalloc(sizeof(Src));
        s2->file = estrdup(targ->pref);
        s2->pref = targ->pref;
        s2->parent = targ;
        s2->node = NULL;
        s2->suff = s;
        s->refCount++;
        s2->children =  0;
        targ->children += 1;
        Lst_AtEnd(ls->l, s2);
#ifdef DEBUG_SRC
        s2->cp = Lst_Init(FALSE);
        Lst_AtEnd(targ->cp, s2);
        printf("1 add %x %x to %x:", targ, s2, ls->l);
        Lst_ForEach(ls->l, PrintAddr, (void *)NULL);
        printf("\n");
#endif
    }
    s2 = emalloc(sizeof(Src));
    s2->file = str_concat(targ->pref, s->name, 0);
    s2->pref = targ->pref;
    s2->parent = targ;
    s2->node = NULL;
    s2->suff = s;
    s->refCount++;
    s2->children = 0;
    targ->children += 1;
    Lst_AtEnd(ls->l, s2);
#ifdef DEBUG_SRC
    s2->cp = Lst_Init(FALSE);
    Lst_AtEnd(targ->cp, s2);
    printf("2 add %x %x to %x:", targ, s2, ls->l);
    Lst_ForEach(ls->l, PrintAddr, (void *)NULL);
    printf("\n");
#endif

    return (0);
}

/*-
 *-----------------------------------------------------------------------
 * SuffAddLevel  --
 *      Add all the children of targ as Src structures to the given list
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      Lots of structures are created and added to the list
 *-----------------------------------------------------------------------
 */
static void
SuffAddLevel(Lst l, Src *targ)
{
    LstSrc         ls;

    ls.s = targ;
    ls.l = l;

    Lst_ForEach(targ->suff->children, SuffAddSrc, &ls);
}

/*-
 *----------------------------------------------------------------------
 * SuffRemoveSrc --
 *      Free all src structures in list that don't have a reference count
 *
 * Results:
 *      True if a src was removed
 *
 * Side Effects:
 *      The memory is free'd.
 *----------------------------------------------------------------------
 */
static int
SuffRemoveSrc(Lst l)
{
    LstNode ln;
    Src *s;
    int t = 0;

    if (Lst_Open(l) == FAILURE) {
        return (0);
    }
#ifdef DEBUG_SRC
    printf("cleaning %lx: ", (unsigned long) l);
    Lst_ForEach(l, PrintAddr, (void *)NULL);
    printf("\n");
#endif


    while ((ln = Lst_Next(l)) != NULL) {
        s = (Src *)Lst_Datum(ln);
        if (s->children == 0) {
            free(s->file);
            if (!s->parent)
                free(s->pref);
            else {
#ifdef DEBUG_SRC
                LstNode ln = Lst_Member(s->parent->cp, s);
                if (ln != NULL)
                    Lst_Remove(s->parent->cp, ln);
#endif
                --s->parent->children;
            }
#ifdef DEBUG_SRC
            printf("free: [l=%x] p=%x %d\n", l, s, s->children);
            Lst_Destroy(s->cp, NOFREE);
#endif
            Lst_Remove(l, ln);
            free(s);
            t |= 1;
            Lst_Close(l);
            return TRUE;
        }
#ifdef DEBUG_SRC
        else {
            printf("keep: [l=%x] p=%x %d: ", l, s, s->children);
            Lst_ForEach(s->cp, PrintAddr, (void *)NULL);
            printf("\n");
        }
#endif
    }

    Lst_Close(l);

    return (t);
}

/*-
 *-----------------------------------------------------------------------
 * SuffFindThem --
 *      Find the first existing file/target in the list srcs
 *
 * Results:
 *      The lowest structure in the chain of transformations
 *
 * Side Effects:
 *      None
 *-----------------------------------------------------------------------
 */
static Src *
SuffFindThem (Lst srcs, Lst slst)
{
    Src            *s;          /* current Src */
    Src            *rs;         /* returned Src */
    char           *ptr;

    rs = NULL;

    while (!Lst_IsEmpty (srcs)) {
        s = Lst_DeQueue(srcs);

        DEBUGF(SUFF, ("\ttrying %s...", s->file));

        /*
         * A file is considered to exist if either a node exists in the
         * graph for it or the file actually exists.
         */
        if (Targ_FindNode(s->file, TARG_NOCREATE) != NULL) {
#ifdef DEBUG_SRC
            printf("remove %x from %x\n", s, srcs);
#endif
            rs = s;
            break;
        }

        if ((ptr = Dir_FindFile(s->file, s->suff->searchPath)) != NULL) {
            rs = s;
#ifdef DEBUG_SRC
            printf("remove %x from %x\n", s, srcs);
#endif
            free(ptr);
            break;
        }

        DEBUGF(SUFF, ("not there\n"));

        SuffAddLevel(srcs, s);
        Lst_AtEnd(slst, s);
    }

    if (rs) {
        DEBUGF(SUFF, ("got it\n"));
    }
    return (rs);
}

/*-
 *-----------------------------------------------------------------------
 * SuffFindCmds --
 *      See if any of the children of the target in the Src structure is
 *      one from which the target can be transformed. If there is one,
 *      a Src structure is put together for it and returned.
 *
 * Results:
 *      The Src structure of the "winning" child, or NULL if no such beast.
 *
 * Side Effects:
 *      A Src structure may be allocated.
 *
 *-----------------------------------------------------------------------
 */
static Src *
SuffFindCmds (Src *targ, Lst slst)
{
    LstNode             ln;     /* General-purpose list node */
    GNode               *t,     /* Target GNode */
                        *s;     /* Source GNode */
    int                 prefLen;/* The length of the defined prefix */
    Suff                *suff;  /* Suffix on matching beastie */
    Src                 *ret;   /* Return value */
    char                *cp;

    t = targ->node;
    Lst_Open(t->children);
    prefLen = strlen(targ->pref);

    while ((ln = Lst_Next(t->children)) != NULL) {
        s = Lst_Datum(ln);

        cp = strrchr(s->name, '/');
        if (cp == NULL) {
            cp = s->name;
        } else {
            cp++;
        }
        if (strncmp(cp, targ->pref, prefLen) == 0) {
            /*
             * The node matches the prefix ok, see if it has a known
             * suffix.
             */
            ln = Lst_Find(sufflist, &cp[prefLen], SuffSuffHasNameP);
            if (ln != NULL) {
                /*
                 * It even has a known suffix, see if there's a transformation
                 * defined between the node's suffix and the target's suffix.
                 *
                 * XXX: Handle multi-stage transformations here, too.
                 */
                suff = Lst_Datum(ln);

                if (Lst_Member(suff->parents, targ->suff) != NULL) {
                    /*
                     * Hot Damn! Create a new Src structure to describe
                     * this transformation (making sure to duplicate the
                     * source node's name so Suff_FindDeps can free it
                     * again (ick)), and return the new structure.
                     */
                    ret = emalloc(sizeof(Src));
                    ret->file = estrdup(s->name);
                    ret->pref = targ->pref;
                    ret->suff = suff;
                    suff->refCount++;
                    ret->parent = targ;
                    ret->node = s;
                    ret->children = 0;
                    targ->children += 1;
#ifdef DEBUG_SRC
                    ret->cp = Lst_Init(FALSE);
                    printf("3 add %x %x\n", targ, ret);
                    Lst_AtEnd(targ->cp, ret);
#endif
                    Lst_AtEnd(slst, ret);
                    DEBUGF(SUFF, ("\tusing existing source %s\n", s->name));
                    return (ret);
                }
            }
        }
    }
    Lst_Close(t->children);
    return (NULL);
}

/*-
 *-----------------------------------------------------------------------
 * SuffExpandChildren --
 *      Expand the names of any children of a given node that contain
 *      variable invocations or file wildcards into actual targets.
 *
 * Results:
 *      == 0 (continue)
 *
 * Side Effects:
 *      The expanded node is removed from the parent's list of children,
 *      and the parent's unmade counter is decremented, but other nodes
 *      may be added.
 *
 *-----------------------------------------------------------------------
 */
static int
SuffExpandChildren(void *cgnp, void *pgnp)
{
    GNode       *cgn = cgnp;
    GNode       *pgn = pgnp;
    GNode       *gn;        /* New source 8) */
    LstNode     prevLN;    /* Node after which new source should be put */
    LstNode     ln;         /* List element for old source */
    char        *cp;        /* Expanded value */

    /*
     * New nodes effectively take the place of the child, so place them
     * after the child
     */
    prevLN = Lst_Member(pgn->children, cgn);

    /*
     * First do variable expansion -- this takes precedence over
     * wildcard expansion. If the result contains wildcards, they'll be gotten
     * to later since the resulting words are tacked on to the end of
     * the children list.
     */
    if (strchr(cgn->name, '$') != NULL) {
        DEBUGF(SUFF, ("Expanding \"%s\"...", cgn->name));
        cp = Var_Subst(NULL, cgn->name, pgn, TRUE);

        if (cp != NULL) {
            Lst     members = Lst_Init(FALSE);

            if (cgn->type & OP_ARCHV) {
                /*
                 * Node was an archive(member) target, so we want to call
                 * on the Arch module to find the nodes for us, expanding
                 * variables in the parent's context.
                 */
                char    *sacrifice = cp;

                Arch_ParseArchive(&sacrifice, members, pgn);
            } else {
                /*
                 * Break the result into a vector of strings whose nodes
                 * we can find, then add those nodes to the members list.
                 * Unfortunately, we can't use brk_string b/c it
                 * doesn't understand about variable specifications with
                 * spaces in them...
                 */
                char        *start;
                char        *initcp = cp;   /* For freeing... */

                for (start = cp; *start == ' ' || *start == '\t'; start++)
                    continue;
                for (cp = start; *cp != '\0'; cp++) {
                    if (*cp == ' ' || *cp == '\t') {
                        /*
                         * White-space -- terminate element, find the node,
                         * add it, skip any further spaces.
                         */
                        *cp++ = '\0';
                        gn = Targ_FindNode(start, TARG_CREATE);
                        Lst_AtEnd(members, gn);
                        while (*cp == ' ' || *cp == '\t') {
                            cp++;
                        }
                        /*
                         * Adjust cp for increment at start of loop, but
                         * set start to first non-space.
                         */
                        start = cp--;
                    } else if (*cp == '$') {
                        /*
                         * Start of a variable spec -- contact variable module
                         * to find the end so we can skip over it.
                         */
                        char    *junk;
                        size_t len;
                        Boolean doFree;

                        junk = Var_Parse(cp, pgn, TRUE, &len, &doFree);
                        if (junk != var_Error) {
                            cp += len - 1;
                        }

                        if (doFree) {
                            free(junk);
                        }
                    } else if (*cp == '\\' && *cp != '\0') {
                        /*
                         * Escaped something -- skip over it
                         */
                        cp++;
                    }
                }

                if (cp != start) {
                    /*
                     * Stuff left over -- add it to the list too
                     */
                    gn = Targ_FindNode(start, TARG_CREATE);
                    Lst_AtEnd(members, gn);
                }
                /*
                 * Point cp back at the beginning again so the variable value
                 * can be freed.
                 */
                cp = initcp;
            }
            /*
             * Add all elements of the members list to the parent node.
             */
            while(!Lst_IsEmpty(members)) {
                gn = Lst_DeQueue(members);

                DEBUGF(SUFF, ("%s...", gn->name));
                if (Lst_Member(pgn->children, gn) == NULL) {
                    Lst_Append(pgn->children, prevLN, gn);
                    prevLN = Lst_Succ(prevLN);
                    Lst_AtEnd(gn->parents, pgn);
                    pgn->unmade++;
                }
            }
            Lst_Destroy(members, NOFREE);
            /*
             * Free the result
             */
            free(cp);
        }
        /*
         * Now the source is expanded, remove it from the list of children to
         * keep it from being processed.
         */
        ln = Lst_Member(pgn->children, cgn);
        pgn->unmade--;
        Lst_Remove(pgn->children, ln);
        DEBUGF(SUFF, ("\n"));
    } else if (Dir_HasWildcards(cgn->name)) {
        Lst     exp;        /* List of expansions */
        Lst     path;       /* Search path along which to expand */

        /*
         * Find a path along which to expand the word.
         *
         * If the word has a known suffix, use that path.
         * If it has no known suffix and we're allowed to use the null
         *   suffix, use its path.
         * Else use the default system search path.
         */
        cp = cgn->name + strlen(cgn->name);
        ln = Lst_Find(sufflist, cp, SuffSuffIsSuffixP);

        DEBUGF(SUFF, ("Wildcard expanding \"%s\"...", cgn->name));

        if (ln != NULL) {
            Suff    *s = Lst_Datum(ln);

            DEBUGF(SUFF, ("suffix is \"%s\"...", s->name));
            path = s->searchPath;
        } else {
            /*
             * Use default search path
             */
            path = dirSearchPath;
        }

        /*
         * Expand the word along the chosen path
         */
        exp = Lst_Init(FALSE);
        Dir_Expand(cgn->name, path, exp);

        while (!Lst_IsEmpty(exp)) {
            /*
             * Fetch next expansion off the list and find its GNode
             */
            cp = Lst_DeQueue(exp);

            DEBUGF(SUFF, ("%s...", cp));
            gn = Targ_FindNode(cp, TARG_CREATE);

            /*
             * If gn isn't already a child of the parent, make it so and
             * up the parent's count of unmade children.
             */
            if (Lst_Member(pgn->children, gn) == NULL) {
                Lst_Append(pgn->children, prevLN, gn);
                prevLN = Lst_Succ(prevLN);
                Lst_AtEnd(gn->parents, pgn);
                pgn->unmade++;
            }
        }

        /*
         * Nuke what's left of the list
         */
        Lst_Destroy(exp, NOFREE);

        /*
         * Now the source is expanded, remove it from the list of children to
         * keep it from being processed.
         */
        ln = Lst_Member(pgn->children, cgn);
        pgn->unmade--;
        Lst_Remove(pgn->children, ln);
        DEBUGF(SUFF, ("\n"));
    }

    return (0);
}

/*-
 *-----------------------------------------------------------------------
 * SuffApplyTransform --
 *      Apply a transformation rule, given the source and target nodes
 *      and suffixes.
 *
 * Results:
 *      TRUE if successful, FALSE if not.
 *
 * Side Effects:
 *      The source and target are linked and the commands from the
 *      transformation are added to the target node's commands list.
 *      All attributes but OP_DEPMASK and OP_TRANSFORM are applied
 *      to the target. The target also inherits all the sources for
 *      the transformation rule.
 *
 *-----------------------------------------------------------------------
 */
static Boolean
SuffApplyTransform(GNode *tGn, GNode *sGn, Suff *t, Suff *s)
{
    LstNode     ln;         /* General node */
    char        *tname;     /* Name of transformation rule */
    GNode       *gn;        /* Node for same */

    if (Lst_Member(tGn->children, sGn) == NULL) {
        /*
         * Not already linked, so form the proper links between the
         * target and source.
         */
        Lst_AtEnd(tGn->children, sGn);
        Lst_AtEnd(sGn->parents, tGn);
        tGn->unmade += 1;
    }

    if ((sGn->type & OP_OPMASK) == OP_DOUBLEDEP) {
        /*
         * When a :: node is used as the implied source of a node, we have
         * to link all its cohorts in as sources as well. Only the initial
         * sGn gets the target in its iParents list, however, as that
         * will be sufficient to get the .IMPSRC variable set for tGn
         */
        for (ln = Lst_First(sGn->cohorts); ln != NULL; ln = Lst_Succ(ln)) {
            gn = Lst_Datum(ln);

            if (Lst_Member(tGn->children, gn) == NULL) {
                /*
                 * Not already linked, so form the proper links between the
                 * target and source.
                 */
                Lst_AtEnd(tGn->children, gn);
                Lst_AtEnd(gn->parents, tGn);
                tGn->unmade += 1;
            }
        }
    }
    /*
     * Locate the transformation rule itself
     */
    tname = str_concat(s->name, t->name, 0);
    ln = Lst_Find(transforms, tname, SuffGNHasNameP);
    free(tname);

    if (ln == NULL) {
        /*
         * Not really such a transformation rule (can happen when we're
         * called to link an OP_MEMBER and OP_ARCHV node), so return
         * FALSE.
         */
        return (FALSE);
    }

    gn = Lst_Datum(ln);

    DEBUGF(SUFF, ("\tapplying %s -> %s to \"%s\"\n", s->name, t->name, tGn->name));

    /*
     * Record last child for expansion purposes
     */
    ln = Lst_Last(tGn->children);

    /*
     * Pass the buck to Make_HandleUse to apply the rule
     */
    Make_HandleUse(gn, tGn);

    /*
     * Deal with wildcards and variables in any acquired sources
     */
    ln = Lst_Succ(ln);
    if (ln != NULL) {
        Lst_ForEachFrom(tGn->children, ln, SuffExpandChildren, tGn);
    }

    /*
     * Keep track of another parent to which this beast is transformed so
     * the .IMPSRC variable can be set correctly for the parent.
     */
    Lst_AtEnd(sGn->iParents, tGn);

    return (TRUE);
}


/*-
 *-----------------------------------------------------------------------
 * SuffFindArchiveDeps --
 *      Locate dependencies for an OP_ARCHV node.
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      Same as Suff_FindDeps
 *
 *-----------------------------------------------------------------------
 */
static void
SuffFindArchiveDeps(GNode *gn, Lst slst)
{
    char        *eoarch;    /* End of archive portion */
    char        *eoname;    /* End of member portion */
    GNode       *mem;       /* Node for member */
    static char *copy[] = { /* Variables to be copied from the member node */
        TARGET,             /* Must be first */
        PREFIX,             /* Must be second */
    };
    int         i;          /* Index into copy and vals */
    Suff        *ms;        /* Suffix descriptor for member */
    char        *name;      /* Start of member's name */

    /*
     * The node is an archive(member) pair. so we must find a
     * suffix for both of them.
     */
    eoarch = strchr(gn->name, '(');
    eoname = strchr(eoarch, ')');

    *eoname = '\0';       /* Nuke parentheses during suffix search */
    *eoarch = '\0';       /* So a suffix can be found */

    name = eoarch + 1;

    /*
     * To simplify things, call Suff_FindDeps recursively on the member now,
     * so we can simply compare the member's .PREFIX and .TARGET variables
     * to locate its suffix. This allows us to figure out the suffix to
     * use for the archive without having to do a quadratic search over the
     * suffix list, backtracking for each one...
     */
    mem = Targ_FindNode(name, TARG_CREATE);
    SuffFindDeps(mem, slst);

    /*
     * Create the link between the two nodes right off
     */
    if (Lst_Member(gn->children, mem) == NULL) {
        Lst_AtEnd(gn->children, mem);
        Lst_AtEnd(mem->parents, gn);
        gn->unmade += 1;
    }

    /*
     * Copy in the variables from the member node to this one.
     */
    for (i = (sizeof(copy) / sizeof(copy[0]))-1; i >= 0; i--) {
        char *p1;
        Var_Set(copy[i], Var_Value(copy[i], mem, &p1), gn);
        free(p1);

    }

    ms = mem->suffix;
    if (ms == NULL) {
        /*
         * Didn't know what it was -- use .NULL suffix if not in make mode
         */
        DEBUGF(SUFF, ("using null suffix\n"));
        ms = suffNull;
    }


    /*
     * Set the other two local variables required for this target.
     */
    Var_Set(MEMBER, name, gn);
    Var_Set(ARCHIVE, gn->name, gn);

    if (ms != NULL) {
        /*
         * Member has a known suffix, so look for a transformation rule from
         * it to a possible suffix of the archive. Rather than searching
         * through the entire list, we just look at suffixes to which the
         * member's suffix may be transformed...
         */
        LstNode     ln;

        /*
         * Use first matching suffix...
         */
        ln = Lst_Find(ms->parents, eoarch, SuffSuffIsSuffixP);

        if (ln != NULL) {
            /*
             * Got one -- apply it
             */
            if (!SuffApplyTransform(gn, mem, Lst_Datum(ln), ms)) {
                DEBUGF(SUFF, ("\tNo transformation from %s -> %s\n",
                       ms->name, ((Suff *)Lst_Datum(ln))->name));
            }
        }
    }

    /*
     * Replace the opening and closing parens now we've no need of the separate
     * pieces.
     */
    *eoarch = '('; *eoname = ')';

    /*
     * Pretend gn appeared to the left of a dependency operator so
     * the user needn't provide a transformation from the member to the
     * archive.
     */
    if (OP_NOP(gn->type)) {
        gn->type |= OP_DEPENDS;
    }

    /*
     * Flag the member as such so we remember to look in the archive for
     * its modification time.
     */
    mem->type |= OP_MEMBER;
}

/*-
 *-----------------------------------------------------------------------
 * SuffFindNormalDeps --
 *      Locate implicit dependencies for regular targets.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      Same as Suff_FindDeps...
 *
 *-----------------------------------------------------------------------
 */
static void
SuffFindNormalDeps(GNode *gn, Lst slst)
{
    char        *eoname;    /* End of name */
    char        *sopref;    /* Start of prefix */
    LstNode     ln;         /* Next suffix node to check */
    Lst         srcs;       /* List of sources at which to look */
    Lst         targs;      /* List of targets to which things can be
                             * transformed. They all have the same file,
                             * but different suff and pref fields */
    Src         *bottom;    /* Start of found transformation path */
    Src         *src;       /* General Src pointer */
    char        *pref;      /* Prefix to use */
    Src         *targ;      /* General Src target pointer */


    eoname = gn->name + strlen(gn->name);

    sopref = gn->name;

    /*
     * Begin at the beginning...
     */
    ln = Lst_First(sufflist);
    srcs = Lst_Init(FALSE);
    targs = Lst_Init(FALSE);

    /*
     * We're caught in a catch-22 here. On the one hand, we want to use any
     * transformation implied by the target's sources, but we can't examine
     * the sources until we've expanded any variables/wildcards they may hold,
     * and we can't do that until we've set up the target's local variables
     * and we can't do that until we know what the proper suffix for the
     * target is (in case there are two suffixes one of which is a suffix of
     * the other) and we can't know that until we've found its implied
     * source, which we may not want to use if there's an existing source
     * that implies a different transformation.
     *
     * In an attempt to get around this, which may not work all the time,
     * but should work most of the time, we look for implied sources first,
     * checking transformations to all possible suffixes of the target,
     * use what we find to set the target's local variables, expand the
     * children, then look for any overriding transformations they imply.
     * Should we find one, we discard the one we found before.
     */

    while (ln != NULL) {
        /*
         * Look for next possible suffix...
         */
        ln = Lst_FindFrom(sufflist, ln, eoname, SuffSuffIsSuffixP);

        if (ln != NULL) {
            int     prefLen;        /* Length of the prefix */
            Src     *target;

            /*
             * Allocate a Src structure to which things can be transformed
             */
            target = emalloc(sizeof(Src));
            target->file = estrdup(gn->name);
            target->suff = Lst_Datum(ln);
            target->suff->refCount++;
            target->node = gn;
            target->parent = NULL;
            target->children = 0;
#ifdef DEBUG_SRC
            target->cp = Lst_Init(FALSE);
#endif

            /*
             * Allocate room for the prefix, whose end is found by subtracting
             * the length of the suffix from the end of the name.
             */
            prefLen = (eoname - target->suff->nameLen) - sopref;
            target->pref = emalloc(prefLen + 1);
            memcpy(target->pref, sopref, prefLen);
            target->pref[prefLen] = '\0';

            /*
             * Add nodes from which the target can be made
             */
            SuffAddLevel(srcs, target);

            /*
             * Record the target so we can nuke it
             */
            Lst_AtEnd(targs, target);

            /*
             * Search from this suffix's successor...
             */
            ln = Lst_Succ(ln);
        }
    }

    /*
     * Handle target of unknown suffix...
     */
    if (Lst_IsEmpty(targs) && suffNull != NULL) {
        DEBUGF(SUFF, ("\tNo known suffix on %s. Using .NULL suffix\n", gn->name));

        targ = emalloc(sizeof(Src));
        targ->file = estrdup(gn->name);
        targ->suff = suffNull;
        targ->suff->refCount++;
        targ->node = gn;
        targ->parent = NULL;
        targ->children = 0;
        targ->pref = estrdup(sopref);
#ifdef DEBUG_SRC
        targ->cp = Lst_Init(FALSE);
#endif

        /*
         * Only use the default suffix rules if we don't have commands
         * or dependencies defined for this gnode
         */
        if (Lst_IsEmpty(gn->commands) && Lst_IsEmpty(gn->children))
            SuffAddLevel(srcs, targ);
        else {
            DEBUGF(SUFF, ("not "));
        }

        DEBUGF(SUFF, ("adding suffix rules\n"));

        Lst_AtEnd(targs, targ);
    }

    /*
     * Using the list of possible sources built up from the target suffix(es),
     * try and find an existing file/target that matches.
     */
    bottom = SuffFindThem(srcs, slst);

    if (bottom == NULL) {
        /*
         * No known transformations -- use the first suffix found for setting
         * the local variables.
         */
        if (!Lst_IsEmpty(targs)) {
            targ = Lst_Datum(Lst_First(targs));
        } else {
            targ = NULL;
        }
    } else {
        /*
         * Work up the transformation path to find the suffix of the
         * target to which the transformation was made.
         */
        for (targ = bottom; targ->parent != NULL; targ = targ->parent)
            continue;
    }

    /*
     * The .TARGET variable we always set to be the name at this point,
     * since it's only set to the path if the thing is only a source and
     * if it's only a source, it doesn't matter what we put here as far
     * as expanding sources is concerned, since it has none...
     */
    Var_Set(TARGET, gn->name, gn);

    pref = (targ != NULL) ? targ->pref : gn->name;
    Var_Set(PREFIX, pref, gn);

    /*
     * Now we've got the important local variables set, expand any sources
     * that still contain variables or wildcards in their names.
     */
    Lst_ForEach(gn->children, SuffExpandChildren, (void *)gn);

    if (targ == NULL) {
        DEBUGF(SUFF, ("\tNo valid suffix on %s\n", gn->name));

sfnd_abort:
        /*
         * Deal with finding the thing on the default search path if the
         * node is only a source (not on the lhs of a dependency operator
         * or [XXX] it has neither children or commands).
         */
        if (OP_NOP(gn->type) ||
            (Lst_IsEmpty(gn->children) && Lst_IsEmpty(gn->commands)))
        {
            gn->path = Dir_FindFile(gn->name,
                                    (targ == NULL ? dirSearchPath :
                                     targ->suff->searchPath));
            if (gn->path != NULL) {
                char *ptr;
                Var_Set(TARGET, gn->path, gn);

                if (targ != NULL) {
                    /*
                     * Suffix known for the thing -- trim the suffix off
                     * the path to form the proper .PREFIX variable.
                     */
                    int         savep = strlen(gn->path) - targ->suff->nameLen;
                    char        savec;

                    if (gn->suffix)
                        gn->suffix->refCount--;
                    gn->suffix = targ->suff;
                    gn->suffix->refCount++;

                    savec = gn->path[savep];
                    gn->path[savep] = '\0';

                    if ((ptr = strrchr(gn->path, '/')) != NULL)
                        ptr++;
                    else
                        ptr = gn->path;

                    Var_Set(PREFIX, ptr, gn);

                    gn->path[savep] = savec;
                } else {
                    /*
                     * The .PREFIX gets the full path if the target has
                     * no known suffix.
                     */
                    if (gn->suffix)
                        gn->suffix->refCount--;
                    gn->suffix = NULL;

                    if ((ptr = strrchr(gn->path, '/')) != NULL)
                        ptr++;
                    else
                        ptr = gn->path;

                    Var_Set(PREFIX, ptr, gn);
                }
            }
        } else {
            /*
             * Not appropriate to search for the thing -- set the
             * path to be the name so Dir_MTime won't go grovelling for
             * it.
             */
            if (gn->suffix)
                gn->suffix->refCount--;
            gn->suffix = (targ == NULL) ? NULL : targ->suff;
            if (gn->suffix)
                gn->suffix->refCount++;
            free(gn->path);
            gn->path = estrdup(gn->name);
        }

        goto sfnd_return;
    }

    /*
     * If the suffix indicates that the target is a library, mark that in
     * the node's type field.
     */
    if (targ->suff->flags & SUFF_LIBRARY) {
        gn->type |= OP_LIB;
    }

    /*
     * Check for overriding transformation rule implied by sources
     */
    if (!Lst_IsEmpty(gn->children)) {
        src = SuffFindCmds(targ, slst);

        if (src != NULL) {
            /*
             * Free up all the Src structures in the transformation path
             * up to, but not including, the parent node.
             */
            while (bottom && bottom->parent != NULL) {
                if (Lst_Member(slst, bottom) == NULL) {
                    Lst_AtEnd(slst, bottom);
                }
                bottom = bottom->parent;
            }
            bottom = src;
        }
    }

    if (bottom == NULL) {
        /*
         * No idea from where it can come -- return now.
         */
        goto sfnd_abort;
    }

    /*
     * We now have a list of Src structures headed by 'bottom' and linked via
     * their 'parent' pointers. What we do next is create links between
     * source and target nodes (which may or may not have been created)
     * and set the necessary local variables in each target. The
     * commands for each target are set from the commands of the
     * transformation rule used to get from the src suffix to the targ
     * suffix. Note that this causes the commands list of the original
     * node, gn, to be replaced by the commands of the final
     * transformation rule. Also, the unmade field of gn is incremented.
     * Etc.
     */
    if (bottom->node == NULL) {
        bottom->node = Targ_FindNode(bottom->file, TARG_CREATE);
    }

    for (src = bottom; src->parent != NULL; src = src->parent) {
        targ = src->parent;

        if (src->node->suffix)
            src->node->suffix->refCount--;
        src->node->suffix = src->suff;
        src->node->suffix->refCount++;

        if (targ->node == NULL) {
            targ->node = Targ_FindNode(targ->file, TARG_CREATE);
        }

        SuffApplyTransform(targ->node, src->node,
                           targ->suff, src->suff);

        if (targ->node != gn) {
            /*
             * Finish off the dependency-search process for any nodes
             * between bottom and gn (no point in questing around the
             * filesystem for their implicit source when it's already
             * known). Note that the node can't have any sources that
             * need expanding, since SuffFindThem will stop on an existing
             * node, so all we need to do is set the standard and System V
             * variables.
             */
            targ->node->type |= OP_DEPS_FOUND;

            Var_Set(PREFIX, targ->pref, targ->node);

            Var_Set(TARGET, targ->node->name, targ->node);
        }
    }

    if (gn->suffix)
        gn->suffix->refCount--;
    gn->suffix = src->suff;
    gn->suffix->refCount++;

    /*
     * So Dir_MTime doesn't go questing for it...
     */
    free(gn->path);
    gn->path = estrdup(gn->name);

    /*
     * Nuke the transformation path and the Src structures left over in the
     * two lists.
     */
sfnd_return:
    if (bottom)
        if (Lst_Member(slst, bottom) == NULL)
            Lst_AtEnd(slst, bottom);

    while (SuffRemoveSrc(srcs) || SuffRemoveSrc(targs))
        continue;

    Lst_Concat(slst, srcs, LST_CONCLINK);
    Lst_Concat(slst, targs, LST_CONCLINK);
}

/*-
 *-----------------------------------------------------------------------
 * Suff_FindDeps  --
 *      Find implicit sources for the target described by the graph node
 *      gn
 *
 * Results:
 *      Nothing.
 *
 * Side Effects:
 *      Nodes are added to the graph below the passed-in node. The nodes
 *      are marked to have their IMPSRC variable filled in. The
 *      PREFIX variable is set for the given node and all its
 *      implied children.
 *
 * Notes:
 *      The path found by this target is the shortest path in the
 *      transformation graph, which may pass through non-existent targets,
 *      to an existing target. The search continues on all paths from the
 *      root suffix until a file is found. I.e. if there's a path
 *      .o -> .c -> .l -> .l,v from the root and the .l,v file exists but
 *      the .c and .l files don't, the search will branch out in
 *      all directions from .o and again from all the nodes on the
 *      next level until the .l,v node is encountered.
 *
 *-----------------------------------------------------------------------
 */
void
Suff_FindDeps(GNode *gn)
{

    SuffFindDeps(gn, srclist);
    while (SuffRemoveSrc(srclist))
        continue;
}


static void
SuffFindDeps(GNode *gn, Lst slst)
{

    if (gn->type & OP_DEPS_FOUND) {
        /*
         * If dependencies already found, no need to do it again...
         */
        return;
    } else {
        gn->type |= OP_DEPS_FOUND;
    }

    DEBUGF(SUFF, ("SuffFindDeps (%s)\n", gn->name));

    if (gn->type & OP_ARCHV) {
        SuffFindArchiveDeps(gn, slst);
    } else if (gn->type & OP_LIB) {
        /*
         * If the node is a library, it is the arch module's job to find it
         * and set the TARGET variable accordingly. We merely provide the
         * search path, assuming all libraries end in ".a" (if the suffix
         * hasn't been defined, there's nothing we can do for it, so we just
         * set the TARGET variable to the node's name in order to give it a
         * value).
         */
        LstNode ln;
        Suff    *s;

        ln = Lst_Find(sufflist, LIBSUFF, SuffSuffHasNameP);
        if (gn->suffix)
            gn->suffix->refCount--;
        if (ln != NULL) {
            gn->suffix = s = Lst_Datum (ln);
            gn->suffix->refCount++;
            Arch_FindLib(gn, s->searchPath);
        } else {
            gn->suffix = NULL;
            Var_Set(TARGET, gn->name, gn);
        }
        /*
         * Because a library (-lfoo) target doesn't follow the standard
         * filesystem conventions, we don't set the regular variables for
         * the thing. .PREFIX is simply made empty...
         */
        Var_Set(PREFIX, "", gn);
    } else {
        SuffFindNormalDeps(gn, slst);
    }
}

/*-
 *-----------------------------------------------------------------------
 * Suff_SetNull --
 *      Define which suffix is the null suffix.
 *
 * Results:
 *      None.
 *
 * Side Effects:
 *      'suffNull' is altered.
 *
 * Notes:
 *      Need to handle the changing of the null suffix gracefully so the
 *      old transformation rules don't just go away.
 *
 *-----------------------------------------------------------------------
 */
void
Suff_SetNull(char *name)
{
    Suff    *s;
    LstNode ln;

    ln = Lst_Find(sufflist, name, SuffSuffHasNameP);
    if (ln != NULL) {
        s = Lst_Datum(ln);
        if (suffNull != NULL) {
            suffNull->flags &= ~SUFF_NULL;
        }
        s->flags |= SUFF_NULL;
        /*
         * XXX: Here's where the transformation mangling would take place
         */
        suffNull = s;
    } else {
        Parse_Error(PARSE_WARNING, "Desired null suffix %s not defined.",
                     name);
    }
}

/*-
 *-----------------------------------------------------------------------
 * Suff_Init --
 *      Initialize suffixes module
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      Many
 *-----------------------------------------------------------------------
 */
void
Suff_Init(void)
{

    sufflist = Lst_Init(FALSE);
    suffClean = Lst_Init(FALSE);
    srclist = Lst_Init(FALSE);
    transforms = Lst_Init(FALSE);

    sNum = 0;
    /*
     * Create null suffix for single-suffix rules (POSIX). The thing doesn't
     * actually go on the suffix list or everyone will think that's its
     * suffix.
     */
    emptySuff = suffNull = emalloc(sizeof(Suff));

    suffNull->name = estrdup("");
    suffNull->nameLen = 0;
    suffNull->searchPath = Lst_Init(FALSE);
    Dir_Concat(suffNull->searchPath, dirSearchPath);
    suffNull->children = Lst_Init(FALSE);
    suffNull->parents = Lst_Init(FALSE);
    suffNull->ref = Lst_Init(FALSE);
    suffNull->sNum = sNum++;
    suffNull->flags = SUFF_NULL;
    suffNull->refCount = 1;
}

/*-
 *----------------------------------------------------------------------
 * Suff_End --
 *      Cleanup the this module
 *
 * Results:
 *      None
 *
 * Side Effects:
 *      The memory is free'd.
 *----------------------------------------------------------------------
 */

void
Suff_End(void)
{

    Lst_Destroy(sufflist, SuffFree);
    Lst_Destroy(suffClean, SuffFree);
    if (suffNull)
        SuffFree(suffNull);
    Lst_Destroy(srclist, NOFREE);
    Lst_Destroy(transforms, NOFREE);
}

/********************* DEBUGGING FUNCTIONS **********************/

static int
SuffPrintName(void *s, void *dummy __unused)
{

    printf("`%s' ", ((Suff *)s)->name);
    return (0);
}

static int
SuffPrintSuff(void *sp, void *dummy __unused)
{
    Suff    *s = sp;
    int     flags;
    int     flag;

    printf("# `%s' [%d] ", s->name, s->refCount);

    flags = s->flags;
    if (flags) {
        fputs(" (", stdout);
        while (flags) {
            flag = 1 << (ffs(flags) - 1);
            flags &= ~flag;
            switch (flag) {
                case SUFF_NULL:
                    printf("NULL");
                    break;
                case SUFF_INCLUDE:
                    printf("INCLUDE");
                    break;
                case SUFF_LIBRARY:
                    printf("LIBRARY");
                    break;
                default:
                    break;
            }
            fputc(flags ? '|' : ')', stdout);
        }
    }
    fputc('\n', stdout);
    printf("#\tTo: ");
    Lst_ForEach(s->parents, SuffPrintName, (void *)NULL);
    fputc('\n', stdout);
    printf("#\tFrom: ");
    Lst_ForEach(s->children, SuffPrintName, (void *)NULL);
    fputc('\n', stdout);
    printf("#\tSearch Path: ");
    Dir_PrintPath(s->searchPath);
    fputc('\n', stdout);
    return (0);
}

static int
SuffPrintTrans(void *tp, void *dummy __unused)
{
    GNode   *t = tp;

    printf("%-16s: ", t->name);
    Targ_PrintType(t->type);
    fputc('\n', stdout);
    Lst_ForEach(t->commands, Targ_PrintCmd, (void *)NULL);
    fputc('\n', stdout);
    return (0);
}

void
Suff_PrintAll(void)
{

    printf("#*** Suffixes:\n");
    Lst_ForEach(sufflist, SuffPrintSuff, (void *)NULL);

    printf("#*** Transformations:\n");
    Lst_ForEach(transforms, SuffPrintTrans, (void *)NULL);
}