Update to bmake-20201101

[FreeBSD/FreeBSD.git] / contrib / bmake / suff.c

/*      $NetBSD: suff.c,v 1.230 2020/10/31 11:54:33 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.
 */

/*-
 * 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        Clean up 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.
 *
 *      Suff_FindPath   Return the appropriate path to search in order to
 *                      find the node.
 */

#include "make.h"
#include "dir.h"

/*      "@(#)suff.c     8.4 (Berkeley) 3/21/94" */
MAKE_RCSID("$NetBSD: suff.c,v 1.230 2020/10/31 11:54:33 rillig Exp $");

#define SUFF_DEBUG0(text) DEBUG0(SUFF, text)
#define SUFF_DEBUG1(fmt, arg1) DEBUG1(SUFF, fmt, arg1)
#define SUFF_DEBUG2(fmt, arg1, arg2) DEBUG2(SUFF, fmt, arg1, arg2)
#define SUFF_DEBUG3(fmt, arg1, arg2, arg3) DEBUG3(SUFF, fmt, arg1, arg2, arg3)
#define SUFF_DEBUG4(fmt, arg1, arg2, arg3, arg4) \
        DEBUG4(SUFF, fmt, arg1, arg2, arg3, arg4)

typedef List SuffList;
typedef ListNode SuffListNode;

typedef List SrcList;
typedef ListNode SrcListNode;

static SuffList *sufflist;      /* List of suffixes */
#ifdef CLEANUP
static SuffList *suffClean;     /* List of suffixes to be cleaned */
#endif
static SrcList *srclist;        /* List of sources */
static GNodeList *transforms;   /* List of transformation rules */

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

typedef enum SuffFlags {
    SUFF_INCLUDE        = 0x01, /* One which is #include'd */
    SUFF_LIBRARY        = 0x02, /* One which contains a library */
    SUFF_NULL           = 0x04  /* The empty suffix */
    /* XXX: Why is SUFF_NULL needed? Wouldn't nameLen == 0 mean the same? */
} SuffFlags;

ENUM_FLAGS_RTTI_3(SuffFlags,
                  SUFF_INCLUDE, SUFF_LIBRARY, SUFF_NULL);

typedef List SuffListList;

/*
 * Structure describing an individual suffix.
 */
typedef struct Suff {
    char         *name;         /* The suffix itself, such as ".c" */
    size_t       nameLen;       /* Length of the name, to avoid strlen calls */
    SuffFlags    flags;         /* Type of suffix */
    SearchPath   *searchPath;   /* The path along which files of this suffix
                                 * may be found */
    int          sNum;          /* The suffix number */
    int          refCount;      /* Reference count of list membership
                                 * and several other places */
    SuffList     *parents;      /* Suffixes we have a transformation to */
    SuffList     *children;     /* Suffixes we have a transformation from */
    SuffListList *ref;          /* Lists in which 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
    SrcList *childrenList;
#endif
} Src;

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


static void SuffFindDeps(GNode *, SrcList *);
static void SuffExpandWildcards(GNodeListNode *, GNode *);

        /*************** Lst Predicates ****************/
/*-
 *-----------------------------------------------------------------------
 * SuffStrIsPrefix  --
 *      See if pref is a prefix of str.
 *
 * Input:
 *      pref            possible prefix
 *      str             string to check
 *
 * Results:
 *      NULL if it ain't, pointer to character in str after prefix if so
 *
 * Side Effects:
 *      None
 *-----------------------------------------------------------------------
 */
static const char *
SuffStrIsPrefix(const char *pref, const char *str)
{
    while (*str && *pref == *str) {
        pref++;
        str++;
    }

    return *pref ? NULL : str;
}

/* See if suff is a suffix of str.
 *
 * Input:
 *      s               possible suffix
 *      nameLen         length of the string to examine
 *      nameEnd         end of the string to examine
 *
 * Results:
 *      NULL if it ain't, pointer to the start of suffix in str if it is.
 */
static const char *
SuffSuffGetSuffix(const Suff *s, size_t nameLen, const char *nameEnd)
{
    const char *p1;             /* Pointer into suffix name */
    const char *p2;             /* Pointer into string being examined */

    if (nameLen < s->nameLen)
        return NULL;            /* this string is shorter than the suffix */

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

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

    /* XXX: s->name - 1 invokes undefined behavior */
    return p1 == s->name - 1 ? p2 + 1 : NULL;
}

static Boolean
SuffSuffIsSuffix(const Suff *suff, size_t nameLen, const char *nameEnd)
{
    return SuffSuffGetSuffix(suff, nameLen, nameEnd) != NULL;
}

static Suff *
FindSuffByNameLen(const char *name, size_t nameLen)
{
    SuffListNode *ln;

    for (ln = sufflist->first; ln != NULL; ln = ln->next) {
        Suff *suff = ln->datum;
        if (suff->nameLen == nameLen && memcmp(suff->name, name, nameLen) == 0)
            return suff;
    }
    return NULL;
}

static Suff *
FindSuffByName(const char *name)
{
    return FindSuffByNameLen(name, strlen(name));
}

static GNode *
FindTransformByName(const char *name)
{
    GNodeListNode *ln;
    for (ln = transforms->first; ln != NULL; ln = ln->next) {
        GNode *gn = ln->datum;
        if (strcmp(gn->name, name) == 0)
            return gn;
    }
    return NULL;
}

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

static void
SuffUnRef(SuffList *list, Suff *suff)
{
    SuffListNode *ln = Lst_FindDatum(list, suff);
    if (ln != NULL) {
        Lst_Remove(list, ln);
        suff->refCount--;
    }
}

/* Free up all memory associated with the given suffix structure. */
static void
SuffFree(void *sp)
{
    Suff *s = sp;

    if (s == suffNull)
        suffNull = NULL;

    if (s == emptySuff)
        emptySuff = NULL;

#if 0
    /* We don't delete suffixes in order, so we cannot use this */
    if (s->refCount)
        Punt("Internal error deleting suffix `%s' with refcount = %d", s->name,
            s->refCount);
#endif

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

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

/* Remove the suffix from the list, and free if it is otherwise unused. */
static void
SuffRemove(SuffList *list, Suff *suff)
{
    SuffUnRef(list, suff);
    if (suff->refCount == 0) {
        SuffUnRef(sufflist, suff);
        SuffFree(suff);
    }
}

/* Insert the suffix into the list, keeping the list ordered by suffix
 * numbers. */
static void
SuffInsert(SuffList *list, Suff *suff)
{
    SuffListNode *ln;
    Suff *listSuff = NULL;

    for (ln = list->first; ln != NULL; ln = ln->next) {
        listSuff = ln->datum;
        if (listSuff->sNum >= suff->sNum)
            break;
    }

    if (ln == NULL) {
        SUFF_DEBUG2("inserting \"%s\" (%d) at end of list\n",
                    suff->name, suff->sNum);
        Lst_Append(list, suff);
        suff->refCount++;
        Lst_Append(suff->ref, list);
    } else if (listSuff->sNum != suff->sNum) {
        SUFF_DEBUG4("inserting \"%s\" (%d) before \"%s\" (%d)\n",
                    suff->name, suff->sNum, listSuff->name, listSuff->sNum);
        Lst_InsertBefore(list, ln, suff);
        suff->refCount++;
        Lst_Append(suff->ref, list);
    } else {
        SUFF_DEBUG2("\"%s\" (%d) is already there\n", suff->name, suff->sNum);
    }
}

static Suff *
SuffNew(const char *name)
{
    Suff *s = bmake_malloc(sizeof(Suff));

    s->name = bmake_strdup(name);
    s->nameLen = strlen(s->name);
    s->searchPath = Lst_New();
    s->children = Lst_New();
    s->parents = Lst_New();
    s->ref = Lst_New();
    s->sNum = sNum++;
    s->flags = 0;
    s->refCount = 1;

    return s;
}

/* 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. */
void
Suff_ClearSuffixes(void)
{
#ifdef CLEANUP
    Lst_MoveAll(suffClean, sufflist);
#endif
    sufflist = Lst_New();
    sNum = 0;
    if (suffNull)
        SuffFree(suffNull);
    emptySuff = suffNull = SuffNew("");

    Dir_Concat(suffNull->searchPath, dirSearchPath);
    suffNull->flags = SUFF_NULL;
}

/* Parse a transformation string such as ".c.o" to find its two component
 * suffixes (the source ".c" and the target ".o").  If there are no such
 * suffixes, try a single-suffix transformation as well.
 *
 * Return TRUE if the string is a valid transformation.
 */
static Boolean
SuffParseTransform(const char *str, Suff **out_src, Suff **out_targ)
{
    SuffListNode *ln;
    Suff *singleSrc = 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 (ln = sufflist->first; ln != NULL; ln = ln->next) {
        Suff *src = ln->datum;

        if (SuffStrIsPrefix(src->name, str) == NULL)
            continue;

        if (str[src->nameLen] == '\0') {
            singleSrc = src;
        } else {
            Suff *targ = FindSuffByName(str + src->nameLen);
            if (targ != NULL) {
                *out_src = src;
                *out_targ = targ;
                return TRUE;
            }
        }
    }

    if (singleSrc != 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?
         */
        *out_src = singleSrc;
        *out_targ = suffNull;
        return TRUE;
    }
    return FALSE;
}

/* Return TRUE if the given string is a transformation rule, that is, a
 * concatenation of two known suffixes. */
Boolean
Suff_IsTransform(const char *str)
{
    Suff *src, *targ;

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

/* Add the transformation rule to the list of rules and place the
 * transformation itself in the graph.
 *
 * The transformation is linked to the two suffixes mentioned in the name.
 *
 * Input:
 *      name            must have the form ".from.to" or just ".from"
 *
 * Results:
 *      The created or existing transformation node in the transforms list
 */
GNode *
Suff_AddTransform(const char *name)
{
    GNode         *gn;          /* GNode of transformation rule */
    Suff          *s,           /* source suffix */
                  *t;           /* target suffix */
    Boolean ok;

    gn = FindTransformByName(name);
    if (gn == NULL) {
        /*
         * Make a new graph node for the transformation. It will be filled in
         * by the Parse module.
         */
        gn = Targ_NewGN(name);
        Lst_Append(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.
         */
        Lst_Free(gn->commands);
        Lst_Free(gn->children);
        gn->commands = Lst_New();
        gn->children = Lst_New();
    }

    gn->type = OP_TRANSFORM;

    ok = SuffParseTransform(name, &s, &t);
    assert(ok);
    (void)ok;

    /*
     * link the two together in the proper relationship and order
     */
    SUFF_DEBUG2("defining transformation from `%s' to `%s'\n",
                s->name, t->name);
    SuffInsert(t->children, s);
    SuffInsert(s->parents, t);

    return gn;
}

/* Handle the finish of a transformation definition, removing the
 * transformation from the graph if it has neither commands nor sources.
 *
 * If the node has no commands or children, the children and parents lists
 * of the affected suffixes are altered.
 *
 * Input:
 *      gn              Node for transformation
 */
void
Suff_EndTransform(GNode *gn)
{
    if ((gn->type & OP_DOUBLEDEP) && !Lst_IsEmpty(gn->cohorts))
        gn = gn->cohorts->last->datum;
    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)) {
            SuffList *p;

            SUFF_DEBUG2("deleting transformation from `%s' to `%s'\n",
                        s->name, t->name);

            /*
             * Store s->parents because s could be deleted in SuffRemove
             */
            p = s->parents;

            /*
             * Remove the source from the target's children list. We check for a
             * nil 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(p, t);
        }
    } else if (gn->type & OP_TRANSFORM) {
        SUFF_DEBUG1("transformation %s complete\n", gn->name);
    }
}

/* Called from Suff_AddSuffix 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.
 *
 * The appropriate links will be made between this suffix and others if
 * transformation rules exist for it.
 *
 * Input:
 *      transform       Transformation to test
 *      suff            Suffix to rebuild
 */
static void
SuffRebuildGraph(GNode *transform, Suff *suff)
{
    const char *name = transform->name;
    size_t nameLen = strlen(name);
    const char *toName;

    /*
     * First see if it is a transformation from this suffix.
     */
    toName = SuffStrIsPrefix(suff->name, name);
    if (toName != NULL) {
        Suff *to = FindSuffByName(toName);
        if (to != NULL) {
            /* Link in and return, since it can't be anything else. */
            SuffInsert(to->children, suff);
            SuffInsert(suff->parents, to);
            return;
        }
    }

    /*
     * Not from, maybe to?
     */
    toName = SuffSuffGetSuffix(suff, nameLen, name + nameLen);
    if (toName != NULL) {
        Suff *from = FindSuffByNameLen(name, (size_t)(toName - name));

        if (from != NULL) {
            /* establish the proper relationship */
            SuffInsert(suff->children, from);
            SuffInsert(from->parents, suff);
        }
    }
}

/* During Suff_AddSuffix, search through the list of existing targets and find
 * if any of the existing targets can be turned into a transformation rule.
 *
 * If such a target is found and the target is the current main target, the
 * main target is set to NULL and the next target examined (if that exists)
 * becomes the main target.
 *
 * Results:
 *      TRUE iff a new main target has been selected.
 */
static Boolean
SuffScanTargets(GNode *target, GNode **inout_main, Suff *gs_s, Boolean *gs_r)
{
    Suff *s, *t;
    char *ptr;

    if (*inout_main == NULL && *gs_r && !(target->type & OP_NOTARGET)) {
        *inout_main = target;
        Targ_SetMain(target);
        return TRUE;
    }

    if (target->type == OP_TRANSFORM)
        return FALSE;

    if ((ptr = strstr(target->name, gs_s->name)) == NULL ||
        ptr == target->name)
        return FALSE;

    if (SuffParseTransform(target->name, &s, &t)) {
        if (*inout_main == target) {
            *gs_r = TRUE;
            *inout_main = NULL;
            Targ_SetMain(NULL);
        }
        Lst_Free(target->children);
        target->children = Lst_New();
        target->type = OP_TRANSFORM;
        /*
         * link the two together in the proper relationship and order
         */
        SUFF_DEBUG2("defining transformation from `%s' to `%s'\n",
                    s->name, t->name);
        SuffInsert(t->children, s);
        SuffInsert(s->parents, t);
    }
    return FALSE;
}

/* Look at all existing targets to see if adding this suffix will make one
 * of the current targets mutate into a suffix rule.
 *
 * This is ugly, but other makes treat all targets that start with a '.' as
 * suffix rules. */
static void
UpdateTargets(GNode **inout_main, Suff *s)
{
    Boolean r = FALSE;
    GNodeListNode *ln;
    for (ln = Targ_List()->first; ln != NULL; ln = ln->next) {
        GNode *gn = ln->datum;
        if (SuffScanTargets(gn, inout_main, s, &r))
            break;
    }
}

/* Add the suffix to the end of the list of known suffixes.
 * Should we restructure the suffix graph? Make doesn't...
 *
 * 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.
 * The mainNode passed can be modified if a target mutated into a
 * transform and that target happened to be the main target.
 *
 * Input:
 *      name            the name of the suffix to add
 */
void
Suff_AddSuffix(const char *name, GNode **inout_main)
{
    GNodeListNode *ln;

    Suff *s = FindSuffByName(name);
    if (s != NULL)
        return;

    s = SuffNew(name);
    Lst_Append(sufflist, s);

    UpdateTargets(inout_main, s);

    /*
     * Look for any existing transformations from or to this suffix.
     * XXX: Only do this after a Suff_ClearSuffixes?
     */
    for (ln = transforms->first; ln != NULL; ln = ln->next)
        SuffRebuildGraph(ln->datum, s);
}

/* Return the search path for the given suffix, or NULL. */
SearchPath *
Suff_GetPath(const char *sname)
{
    Suff *s = FindSuffByName(sname);
    return s != NULL ? s->searchPath : NULL;
}

/* Extend the search paths for all suffixes to include the default search
 * path.
 *
 * 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)
{
    SuffListNode *ln;
    char *ptr;
    SearchPath *inIncludes; /* Cumulative .INCLUDES path */
    SearchPath *inLibs;     /* Cumulative .LIBS path */

    inIncludes = Lst_New();
    inLibs = Lst_New();

    for (ln = sufflist->first; ln != NULL; ln = ln->next) {
        Suff *s = ln->datum;
        if (!Lst_IsEmpty(s->searchPath)) {
#ifdef INCLUDES
            if (s->flags & SUFF_INCLUDE) {
                Dir_Concat(inIncludes, s->searchPath);
            }
#endif
#ifdef LIBRARIES
            if (s->flags & SUFF_LIBRARY) {
                Dir_Concat(inLibs, s->searchPath);
            }
#endif
            Dir_Concat(s->searchPath, dirSearchPath);
        } else {
            Lst_Destroy(s->searchPath, Dir_Destroy);
            s->searchPath = Dir_CopyDirSearchPath();
        }
    }

    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);
}

/* 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.
 * The SUFF_INCLUDE bit is set in the suffix's flags field.
 *
 * Input:
 *      sname           Name of the suffix to mark
 */
void
Suff_AddInclude(const char *sname)
{
    Suff *suff = FindSuffByName(sname);
    if (suff != NULL)
        suff->flags |= SUFF_INCLUDE;
}

/* 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.
 * The SUFF_LIBRARY bit is set in the suffix's flags field.
 *
 * Input:
 *      sname           Name of the suffix to mark
 */
void
Suff_AddLib(const char *sname)
{
    Suff *suff = FindSuffByName(sname);
    if (suff != NULL)
        suff->flags |= SUFF_LIBRARY;
}

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

#ifdef DEBUG_SRC
static void
SrcList_PrintAddrs(SrcList *srcList)
{
    SrcListNode *ln;
    for (ln = srcList->first; ln != NULL; ln = ln->next)
        debug_printf(" %p", ln->datum);
    debug_printf("\n");
}
#endif

static Src *
SrcNew(char *name, char *pref, Suff *suff, Src *parent, GNode *gn)
{
    Src *src = bmake_malloc(sizeof *src);

    src->file = name;
    src->pref = pref;
    src->suff = suff;
    src->parent = parent;
    src->node = gn;
    src->children = 0;
#ifdef DEBUG_SRC
    src->childrenList = Lst_New();
#endif

    return src;
}

static void
SuffAddSrc(Suff *suff, SrcList *srcList, Src *targ, char *srcName,
           const char *debug_tag)
{
    Src *s2 = SrcNew(srcName, targ->pref, suff, targ, NULL);
    suff->refCount++;
    targ->children++;
    Lst_Append(srcList, s2);
#ifdef DEBUG_SRC
    Lst_Append(targ->childrenList, s2);
    debug_printf("%s add suff %p src %p to list %p:",
                 debug_tag, targ, s2, srcList);
    SrcList_PrintAddrs(srcList);
#endif
}

/* 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.
 *
 * Input:
 *      suff            suffix for which to create a Src structure
 *      srcList         list for the new Src
 *      targ            parent for the new Src
 */
static void
SuffAddSources(Suff *suff, SrcList *srcList, Src *targ)
{
    if ((suff->flags & SUFF_NULL) && suff->name[0] != '\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...
         */
        SuffAddSrc(suff, srcList, targ, bmake_strdup(targ->pref), "1");
    }
    SuffAddSrc(suff, srcList, targ, str_concat2(targ->pref, suff->name), "2");
}

/* Add all the children of targ as Src structures to the given list.
 *
 * Input:
 *      l               list to which to add the new level
 *      targ            Src structure to use as the parent
 */
static void
SuffAddLevel(SrcList *l, Src *targ)
{
    SrcListNode *ln;
    for (ln = targ->suff->children->first; ln != NULL; ln = ln->next) {
        Suff *childSuff = ln->datum;
        SuffAddSources(childSuff, l, targ);
    }
}

/* Free the first Src in the list that is not referenced anymore.
 * Return whether a Src was removed. */
static Boolean
SuffRemoveSrc(SrcList *l)
{
    SrcListNode *ln;

#ifdef DEBUG_SRC
    debug_printf("cleaning list %p:", l);
    SrcList_PrintAddrs(l);
#endif

    for (ln = l->first; ln != NULL; ln = ln->next) {
        Src *s = ln->datum;

        if (s->children == 0) {
            free(s->file);
            if (s->parent == NULL)
                free(s->pref);
            else {
#ifdef DEBUG_SRC
                SrcListNode *ln2 = Lst_FindDatum(s->parent->childrenList, s);
                if (ln2 != NULL)
                    Lst_Remove(s->parent->childrenList, ln2);
#endif
                s->parent->children--;
            }
#ifdef DEBUG_SRC
            debug_printf("free: list %p src %p children %d\n",
                         l, s, s->children);
            Lst_Free(s->childrenList);
#endif
            Lst_Remove(l, ln);
            free(s);
            return TRUE;
        }
#ifdef DEBUG_SRC
        else {
            debug_printf("keep: list %p src %p children %d:",
                         l, s, s->children);
            SrcList_PrintAddrs(s->childrenList);
        }
#endif
    }

    return FALSE;
}

/* Find the first existing file/target in the list srcs.
 *
 * Input:
 *      srcs            list of Src structures to search through
 *
 * Results:
 *      The lowest structure in the chain of transformations, or NULL.
 */
static Src *
SuffFindThem(SrcList *srcs, SrcList *slst)
{
    Src *retsrc = NULL;

    while (!Lst_IsEmpty(srcs)) {
        Src *src = Lst_Dequeue(srcs);

        SUFF_DEBUG1("\ttrying %s...", src->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(src->file) != NULL) {
#ifdef DEBUG_SRC
            debug_printf("remove from list %p src %p\n", srcs, src);
#endif
            retsrc = src;
            break;
        }

        {
            char *file = Dir_FindFile(src->file, src->suff->searchPath);
            if (file != NULL) {
                retsrc = src;
#ifdef DEBUG_SRC
                debug_printf("remove from list %p src %p\n", srcs, src);
#endif
                free(file);
                break;
            }
        }

        SUFF_DEBUG0("not there\n");

        SuffAddLevel(srcs, src);
        Lst_Append(slst, src);
    }

    if (retsrc) {
        SUFF_DEBUG0("got it\n");
    }
    return retsrc;
}

/* 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.
 *
 * Input:
 *      targ            Src to play with
 *
 * Results:
 *      The Src of the "winning" child, or NULL.
 */
static Src *
SuffFindCmds(Src *targ, SrcList *slst)
{
    GNodeListNode *gln;
    GNode *tgn;                 /* Target GNode */
    GNode *sgn;                 /* Source GNode */
    size_t prefLen;             /* The length of the defined prefix */
    Suff *suff;                 /* Suffix on matching beastie */
    Src *ret;                   /* Return value */
    char *cp;

    tgn = targ->node;
    prefLen = strlen(targ->pref);

    for (gln = tgn->children->first; gln != NULL; gln = gln->next) {
        sgn = gln->datum;

        if (sgn->type & OP_OPTIONAL && Lst_IsEmpty(tgn->commands)) {
            /*
             * We haven't looked to see if .OPTIONAL files exist yet, so
             * don't use one as the implicit source.
             * This allows us to use .OPTIONAL in .depend files so make won't
             * complain "don't know how to make xxx.h' when a dependent file
             * has been moved/deleted.
             */
            continue;
        }

        cp = strrchr(sgn->name, '/');
        if (cp == NULL) {
            cp = sgn->name;
        } else {
            cp++;
        }
        if (strncmp(cp, targ->pref, prefLen) != 0)
            continue;
        /*
         * The node matches the prefix ok, see if it has a known
         * suffix.
         */
        suff = FindSuffByName(cp + prefLen);
        if (suff == NULL)
            continue;

        /*
         * 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.
         */

        /* XXX: Can targ->suff be NULL here? */
        if (targ->suff != NULL &&
            Lst_FindDatum(suff->parents, targ->suff) != NULL)
            break;
    }

    if (gln == NULL)
        return 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 = SrcNew(bmake_strdup(sgn->name), targ->pref, suff, targ, sgn);
    suff->refCount++;
    targ->children++;
#ifdef DEBUG_SRC
    debug_printf("3 add targ %p ret %p\n", targ, ret);
    Lst_Append(targ->childrenList, ret);
#endif
    Lst_Append(slst, ret);
    SUFF_DEBUG1("\tusing existing source %s\n", sgn->name);
    return ret;
}

/* Expand the names of any children of a given node that contain variable
 * expressions or file wildcards into actual targets.
 *
 * 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.
 *
 * Input:
 *      cln             Child to examine
 *      pgn             Parent node being processed
 */
static void
SuffExpandChildren(GNodeListNode *cln, GNode *pgn)
{
    GNode *cgn = cln->datum;
    GNode *gn;                  /* New source 8) */
    char *cp;                   /* Expanded value */

    if (!Lst_IsEmpty(cgn->order_pred) || !Lst_IsEmpty(cgn->order_succ))
        /* It is all too hard to process the result of .ORDER */
        return;

    if (cgn->type & OP_WAIT)
        /* Ignore these (& OP_PHONY ?) */
        return;

    /*
     * 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) {
        SuffExpandWildcards(cln, pgn);
        return;
    }

    SUFF_DEBUG1("Expanding \"%s\"...", cgn->name);
    (void)Var_Subst(cgn->name, pgn, VARE_UNDEFERR|VARE_WANTRES, &cp);
    /* TODO: handle errors */

    {
        GNodeList *members = Lst_New();

        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;

            (void)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;
            cp = start;
            while (*cp != '\0') {
                if (*cp == ' ' || *cp == '\t') {
                    /*
                     * White-space -- terminate element, find the node,
                     * add it, skip any further spaces.
                     */
                    *cp++ = '\0';
                    gn = Targ_GetNode(start);
                    Lst_Append(members, gn);
                    while (*cp == ' ' || *cp == '\t') {
                        cp++;
                    }
                    start = cp;         /* Continue at the next non-space. */
                } else if (*cp == '$') {
                    /*
                     * Start of a variable spec -- contact variable module
                     * to find the end so we can skip over it.
                     */
                    const char *nested_p = cp;
                    const char  *junk;
                    void        *freeIt;

                    /* XXX: Why VARE_WANTRES when the result is not used? */
                    (void)Var_Parse(&nested_p, pgn,
                                    VARE_UNDEFERR|VARE_WANTRES,
                                    &junk, &freeIt);
                    /* TODO: handle errors */
                    if (junk == var_Error) {
                        Parse_Error(PARSE_FATAL,
                                    "Malformed variable expression at \"%s\"",
                                    cp);
                        cp++;
                    } else {
                        cp += nested_p - cp;
                    }

                    free(freeIt);
                } else if (*cp == '\\' && cp[1] != '\0') {
                    /*
                     * Escaped something -- skip over it
                     */
                    /* XXX: In other places, escaping at this syntactical
                     * position is done by a '$', not a '\'.  The '\' is only
                     * used in variable modifiers. */
                    cp += 2;
                } else {
                    cp++;
                }
            }

            if (cp != start) {
                /*
                 * Stuff left over -- add it to the list too
                 */
                gn = Targ_GetNode(start);
                Lst_Append(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);

            SUFF_DEBUG1("%s...", gn->name);
            /* Add gn to the parents child list before the original child */
            Lst_InsertBefore(pgn->children, cln, gn);
            Lst_Append(gn->parents, pgn);
            pgn->unmade++;
            /* Expand wildcards on new node */
            SuffExpandWildcards(cln->prev, pgn);
        }
        Lst_Free(members);

        /*
         * Free the result
         */
        free(cp);
    }

    SUFF_DEBUG0("\n");

    /*
     * Now the source is expanded, remove it from the list of children to
     * keep it from being processed.
     */
    pgn->unmade--;
    Lst_Remove(pgn->children, cln);
    Lst_Remove(cgn->parents, Lst_FindDatum(cgn->parents, pgn));
}

static void
SuffExpandWildcards(GNodeListNode *cln, GNode *pgn)
{
    GNode *cgn = cln->datum;
    StringList *explist;

    if (!Dir_HasWildcards(cgn->name))
        return;

    /*
     * Expand the word along the chosen path
     */
    explist = Lst_New();
    Dir_Expand(cgn->name, Suff_FindPath(cgn), explist);

    while (!Lst_IsEmpty(explist)) {
        GNode   *gn;
        /*
         * Fetch next expansion off the list and find its GNode
         */
        char *cp = Lst_Dequeue(explist);

        SUFF_DEBUG1("%s...", cp);
        gn = Targ_GetNode(cp);

        /* Add gn to the parents child list before the original child */
        Lst_InsertBefore(pgn->children, cln, gn);
        Lst_Append(gn->parents, pgn);
        pgn->unmade++;
    }

    Lst_Free(explist);

    SUFF_DEBUG0("\n");

    /*
     * Now the source is expanded, remove it from the list of children to
     * keep it from being processed.
     */
    pgn->unmade--;
    Lst_Remove(pgn->children, cln);
    Lst_Remove(cgn->parents, Lst_FindDatum(cgn->parents, pgn));
}

/* Find a path along which to expand the node.
 *
 * If the word has a known suffix, use that path.
 * If it has no known suffix, use the default system search path.
 *
 * Input:
 *      gn              Node being examined
 *
 * Results:
 *      The appropriate path to search for the GNode.
 */
SearchPath *
Suff_FindPath(GNode* gn)
{
    Suff *suff = gn->suffix;

    if (suff == NULL) {
        char *name = gn->name;
        size_t nameLen = strlen(gn->name);
        SuffListNode *ln;
        for (ln = sufflist->first; ln != NULL; ln = ln->next)
            if (SuffSuffIsSuffix(ln->datum, nameLen, name + nameLen))
                break;

        SUFF_DEBUG1("Wildcard expanding \"%s\"...", gn->name);
        if (ln != NULL)
            suff = ln->datum;
        /* XXX: Here we can save the suffix so we don't have to do this again */
    }

    if (suff != NULL) {
        SUFF_DEBUG1("suffix is \"%s\"...\n", suff->name);
        return suff->searchPath;
    } else {
        SUFF_DEBUG0("\n");
        return dirSearchPath;   /* Use default search path */
    }
}

/* Apply a transformation rule, given the source and target nodes and
 * suffixes.
 *
 * Input:
 *      tGn             Target node
 *      sGn             Source node
 *      t               Target suffix
 *      s               Source suffix
 *
 * 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)
{
    GNodeListNode *ln, *nln;    /* General node */
    char *tname;                /* Name of transformation rule */
    GNode *gn;                  /* Node for same */

    /*
     * Form the proper links between the target and source.
     */
    Lst_Append(tGn->children, sGn);
    Lst_Append(sGn->parents, tGn);
    tGn->unmade++;

    /*
     * Locate the transformation rule itself
     */
    tname = str_concat2(s->name, t->name);
    gn = FindTransformByName(tname);
    free(tname);

    if (gn == 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;
    }

    SUFF_DEBUG3("\tapplying %s -> %s to \"%s\"\n", s->name, t->name, tGn->name);

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

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

    /*
     * Deal with wildcards and variables in any acquired sources
     */
    for (ln = ln != NULL ? ln->next : NULL; ln != NULL; ln = nln) {
        nln = ln->next;
        SuffExpandChildren(ln, tGn);
    }

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

    return TRUE;
}


/* Locate dependencies for an OP_ARCHV node.
 *
 * Input:
 *      gn              Node for which to locate dependencies
 *
 * Side Effects:
 *      Same as Suff_FindDeps
 */
static void
SuffFindArchiveDeps(GNode *gn, SrcList *slst)
{
    char *eoarch;               /* End of archive portion */
    char *eoname;               /* End of member portion */
    GNode *mem;                 /* Node for member */
    SuffListNode *ln, *nln;     /* Next suffix node to check */
    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, ')');

    /*
     * Caller guarantees the format `libname(member)', via
     * Arch_ParseArchive.
     */
    assert(eoarch != NULL);
    assert(eoname != NULL);

    *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_GetNode(name);
    SuffFindDeps(mem, slst);

    /*
     * Create the link between the two nodes right off
     */
    Lst_Append(gn->children, mem);
    Lst_Append(mem->parents, gn);
    gn->unmade++;

    /*
     * Copy in the variables from the member node to this one.
     */
    Var_Set(PREFIX, GNode_VarPrefix(mem), gn);
    Var_Set(TARGET, GNode_VarTarget(mem), gn);

    ms = mem->suffix;
    if (ms == NULL) {
        /*
         * Didn't know what it was -- use .NULL suffix if not in make mode
         */
        SUFF_DEBUG0("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);

    /*
     * Set $@ for compatibility with other makes
     */
    Var_Set(TARGET, gn->name, gn);

    /*
     * Now we've got the important local variables set, expand any sources
     * that still contain variables or wildcards in their names.
     */
    for (ln = gn->children->first; ln != NULL; ln = nln) {
        nln = ln->next;
        SuffExpandChildren(ln, 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...
         */
        size_t nameLen = (size_t)(eoarch - gn->name);

        /* Use first matching suffix... */
        for (ln = ms->parents->first; ln != NULL; ln = ln->next)
            if (SuffSuffIsSuffix(ln->datum, nameLen, eoarch))
                break;

        if (ln != NULL) {
            /*
             * Got one -- apply it
             */
            Suff *suff = ln->datum;
            if (!SuffApplyTransform(gn, mem, suff, ms)) {
                SUFF_DEBUG2("\tNo transformation from %s -> %s\n",
                            ms->name, suff->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 (!GNode_IsTarget(gn)) {
        gn->type |= OP_DEPENDS;
    }

    /*
     * Flag the member as such so we remember to look in the archive for
     * its modification time. The OP_JOIN | OP_MADE is needed because this
     * target should never get made.
     */
    mem->type |= OP_MEMBER | OP_JOIN | OP_MADE;
}

static void
SuffFindNormalDepsKnown(const char *name, size_t nameLen, GNode *gn,
                        SrcList *srcs, SrcList *targs)
{
    SuffListNode *ln;
    Src *targ;
    char *pref;

    for (ln = sufflist->first; ln != NULL; ln = ln->next) {
        Suff *suff = ln->datum;
        if (!SuffSuffIsSuffix(suff, nameLen, name + nameLen))
            continue;

        pref = bmake_strldup(name, (size_t)(nameLen - suff->nameLen));
        targ = SrcNew(bmake_strdup(gn->name), pref, suff, NULL, gn);
        suff->refCount++;

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

        /*
         * Record the target so we can nuke it
         */
        Lst_Append(targs, targ);
    }
}

static void
SuffFindNormalDepsUnknown(GNode *gn, const char *sopref,
                          SrcList *srcs, SrcList *targs)
{
    Src *targ;

    if (!Lst_IsEmpty(targs) || suffNull == NULL)
        return;

    SUFF_DEBUG1("\tNo known suffix on %s. Using .NULL suffix\n", gn->name);

    targ = SrcNew(bmake_strdup(gn->name), bmake_strdup(sopref),
                  suffNull, NULL, gn);
    targ->suff->refCount++;

    /*
     * Only use the default suffix rules if we don't have commands
     * defined for this gnode; traditional make programs used to
     * not define suffix rules if the gnode had children but we
     * don't do this anymore.
     */
    if (Lst_IsEmpty(gn->commands))
        SuffAddLevel(srcs, targ);
    else {
        SUFF_DEBUG0("not ");
    }

    SUFF_DEBUG0("adding suffix rules\n");

    Lst_Append(targs, targ);
}

/*
 * Deal with finding the thing on the default search path. We
 * always do that, not only if the node is only a source (not
 * on the lhs of a dependency operator or [XXX] it has neither
 * children or commands) as the old pmake did.
 */
static void
SuffFindNormalDepsPath(GNode *gn, Src *targ)
{
    if (gn->type & (OP_PHONY | OP_NOPATH))
        return;

    free(gn->path);
    gn->path = Dir_FindFile(gn->name,
                            (targ == NULL ? dirSearchPath :
                             targ->suff->searchPath));
    if (gn->path == NULL)
        return;

    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.
         */
        size_t savep = strlen(gn->path) - targ->suff->nameLen;
        char savec;
        char *ptr;

        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 {
        char *ptr;

        /* 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);
    }
}

/* Locate implicit dependencies for regular targets.
 *
 * Input:
 *      gn              Node for which to find sources
 *
 * Side Effects:
 *      Same as Suff_FindDeps
 */
static void
SuffFindNormalDeps(GNode *gn, SrcList *slst)
{
    SrcList *srcs;              /* List of sources at which to look */
    SrcList *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 */

    const char *name = gn->name;
    size_t nameLen = strlen(name);

    /*
     * Begin at the beginning...
     */
    srcs = Lst_New();
    targs = Lst_New();

    /*
     * 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.
     */
    bottom = NULL;
    targ = NULL;

    if (!(gn->type & OP_PHONY)) {

        SuffFindNormalDepsKnown(name, nameLen, gn, srcs, targs);

        /* Handle target of unknown suffix... */
        SuffFindNormalDepsUnknown(gn, name, srcs, targs);

        /*
         * 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 = targs->first->datum;
            } 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;
        }
    }

    Var_Set(TARGET, GNode_Path(gn), 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.
     */
    {
        SuffListNode *ln, *nln;
        for (ln = gn->children->first; ln != NULL; ln = nln) {
            nln = ln->next;
            SuffExpandChildren(ln, gn);
        }
    }

    if (targ == NULL) {
        SUFF_DEBUG1("\tNo valid suffix on %s\n", gn->name);

sfnd_abort:
        SuffFindNormalDepsPath(gn, targ);
        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_FindDatum(slst, bottom) == NULL) {
                    Lst_Append(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_GetNode(bottom->file);
    }

    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_GetNode(targ->file);
        }

        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++;

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

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

    Lst_MoveAll(slst, srcs);
    Lst_MoveAll(slst, targs);
}


/* Find implicit sources for the target described by the graph node.
 *
 * 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.
 *
 * 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, SrcList *slst)
{
    if (gn->type & OP_DEPS_FOUND)
        return;
    gn->type |= OP_DEPS_FOUND;

    /*
     * Make sure we have these set, may get revised below.
     */
    Var_Set(TARGET, GNode_Path(gn), gn);
    Var_Set(PREFIX, gn->name, gn);

    SUFF_DEBUG1("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).
         */
        Suff *s = FindSuffByName(LIBSUFF);
        if (gn->suffix)
            gn->suffix->refCount--;
        if (s != NULL) {
            gn->suffix = s;
            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);
    }
}

/* Define which suffix is the null suffix.
 *
 * Need to handle the changing of the null suffix gracefully so the old
 * transformation rules don't just go away.
 *
 * Input:
 *      name            Name of null suffix
 */
void
Suff_SetNull(const char *name)
{
    Suff *s = FindSuffByName(name);
    if (s == NULL) {
        Parse_Error(PARSE_WARNING, "Desired null suffix %s not defined.",
                    name);
        return;
    }

    if (suffNull != NULL) {
        suffNull->flags &= ~(unsigned)SUFF_NULL;
    }
    s->flags |= SUFF_NULL;
    /*
     * XXX: Here's where the transformation mangling would take place
     */
    suffNull = s;
}

/* Initialize the suffixes module. */
void
Suff_Init(void)
{
#ifdef CLEANUP
    suffClean = Lst_New();
    sufflist = Lst_New();
#endif
    srclist = Lst_New();
    transforms = Lst_New();

    /*
     * 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.
     */
    Suff_ClearSuffixes();
}


/* Clean up the suffixes module. */
void
Suff_End(void)
{
#ifdef CLEANUP
    Lst_Destroy(sufflist, SuffFree);
    Lst_Destroy(suffClean, SuffFree);
    if (suffNull)
        SuffFree(suffNull);
    Lst_Free(srclist);
    Lst_Free(transforms);
#endif
}


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

static void
PrintSuffNames(const char *prefix, SuffList *suffs)
{
    SuffListNode *ln;

    debug_printf("#\t%s: ", prefix);
    for (ln = suffs->first; ln != NULL; ln = ln->next) {
        Suff *suff = ln->datum;
        debug_printf("%s ", suff->name);
    }
    debug_printf("\n");
}

static void
PrintSuff(Suff *s)
{
    debug_printf("# \"%s\" (num %d, ref %d)", s->name, s->sNum, s->refCount);
    if (s->flags != 0) {
        char flags_buf[SuffFlags_ToStringSize];

        debug_printf(" (%s)",
                     Enum_FlagsToString(flags_buf, sizeof flags_buf,
                                        s->flags, SuffFlags_ToStringSpecs));
    }
    debug_printf("\n");

    PrintSuffNames("To", s->parents);
    PrintSuffNames("From", s->children);

    debug_printf("#\tSearch Path: ");
    Dir_PrintPath(s->searchPath);
    debug_printf("\n");
}

static void
PrintTransformation(GNode *t)
{
    debug_printf("%-16s:", t->name);
    Targ_PrintType(t->type);
    debug_printf("\n");
    Targ_PrintCmds(t);
    debug_printf("\n");
}

void
Suff_PrintAll(void)
{
    debug_printf("#*** Suffixes:\n");
    {
        SuffListNode *ln;
        for (ln = sufflist->first; ln != NULL; ln = ln->next)
            PrintSuff(ln->datum);
    }

    debug_printf("#*** Transformations:\n");
    {
        GNodeListNode *ln;
        for (ln = transforms->first; ln != NULL; ln = ln->next)
            PrintTransformation(ln->datum);
    }
}