Update OpenZFS to 2.0.0-rc3-gfc5966

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

/*      $NetBSD: arch.c,v 1.107 2020/08/30 11:15:05 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.
 */

#ifndef MAKE_NATIVE
static char rcsid[] = "$NetBSD: arch.c,v 1.107 2020/08/30 11:15:05 rillig Exp $";
#else
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)arch.c      8.2 (Berkeley) 1/2/94";
#else
__RCSID("$NetBSD: arch.c,v 1.107 2020/08/30 11:15:05 rillig Exp $");
#endif
#endif /* not lint */
#endif

/*-
 * arch.c --
 *      Functions to manipulate libraries, archives and their members.
 *
 *      Once again, cacheing/hashing comes into play in the manipulation
 * of archives. The first time an archive is referenced, all of its members'
 * headers are read and hashed and the archive closed again. All hashed
 * archives are kept on a list which is searched each time an archive member
 * is referenced.
 *
 * The interface to this module is:
 *      Arch_ParseArchive       Given an archive specification, return a list
 *                              of GNode's, one for each member in the spec.
 *                              FALSE is returned if the specification is
 *                              invalid for some reason.
 *
 *      Arch_Touch              Alter the modification time of the archive
 *                              member described by the given node to be
 *                              the current time.
 *
 *      Arch_TouchLib           Update the modification time of the library
 *                              described by the given node. This is special
 *                              because it also updates the modification time
 *                              of the library's table of contents.
 *
 *      Arch_MTime              Find the modification time of a member of
 *                              an archive *in the archive*. The time is also
 *                              placed in the member's GNode. Returns the
 *                              modification time.
 *
 *      Arch_MemTime            Find the modification time of a member of
 *                              an archive. Called when the member doesn't
 *                              already exist. Looks in the archive for the
 *                              modification time. Returns the modification
 *                              time.
 *
 *      Arch_FindLib            Search for a library along a path. The
 *                              library name in the GNode should be in
 *                              -l<name> format.
 *
 *      Arch_LibOODate          Special function to decide if a library node
 *                              is out-of-date.
 *
 *      Arch_Init               Initialize this module.
 *
 *      Arch_End                Cleanup this module.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include    <sys/types.h>
#include    <sys/stat.h>
#include    <sys/time.h>
#include    <sys/param.h>
#ifdef HAVE_AR_H
#include    <ar.h>
#else
struct ar_hdr {
        char ar_name[16];               /* name */
        char ar_date[12];               /* modification time */
        char ar_uid[6];                 /* user id */
        char ar_gid[6];                 /* group id */
        char ar_mode[8];                /* octal file permissions */
        char ar_size[10];               /* size in bytes */
#ifndef ARFMAG
#define ARFMAG  "`\n"
#endif
        char ar_fmag[2];                /* consistency check */
};
#endif
#if defined(HAVE_RANLIB_H) && !(defined(__ELF__) || defined(NO_RANLIB))
#include    <ranlib.h>
#endif
#include    <stdio.h>
#include    <stdlib.h>
#ifdef HAVE_UTIME_H
#include    <utime.h>
#endif

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

#ifdef TARGET_MACHINE
#undef MAKE_MACHINE
#define MAKE_MACHINE TARGET_MACHINE
#endif
#ifdef TARGET_MACHINE_ARCH
#undef MAKE_MACHINE_ARCH
#define MAKE_MACHINE_ARCH TARGET_MACHINE_ARCH
#endif

static Lst        archives;   /* Lst of archives we've already examined */

typedef struct Arch {
    char          *name;      /* Name of archive */
    Hash_Table    members;    /* All the members of the archive described
                               * by <name, struct ar_hdr *> key/value pairs */
    char          *fnametab;  /* Extended name table strings */
    size_t        fnamesize;  /* Size of the string table */
} Arch;

static struct ar_hdr *ArchStatMember(const char *, const char *, Boolean);
static FILE *ArchFindMember(const char *, const char *,
                            struct ar_hdr *, const char *);
#if defined(__svr4__) || defined(__SVR4) || defined(__ELF__)
#define SVR4ARCHIVES
static int ArchSVR4Entry(Arch *, char *, size_t, FILE *);
#endif


#if defined(_AIX)
# define AR_NAME _ar_name.ar_name
# define AR_FMAG _ar_name.ar_fmag
# define SARMAG  SAIAMAG
# define ARMAG   AIAMAG
# define ARFMAG  AIAFMAG
#endif
#ifndef  AR_NAME
# define AR_NAME ar_name
#endif
#ifndef  AR_DATE
# define AR_DATE ar_date
#endif
#ifndef  AR_SIZE
# define AR_SIZE ar_size
#endif
#ifndef  AR_FMAG
# define AR_FMAG ar_fmag
#endif
#ifndef ARMAG
# define ARMAG  "!<arch>\n"
#endif
#ifndef SARMAG
# define SARMAG 8
#endif

#define AR_MAX_NAME_LEN     (sizeof(arh.AR_NAME)-1)

#ifdef CLEANUP
static void
ArchFree(void *ap)
{
    Arch *a = (Arch *)ap;
    Hash_Search   search;
    Hash_Entry    *entry;

    /* Free memory from hash entries */
    for (entry = Hash_EnumFirst(&a->members, &search);
         entry != NULL;
         entry = Hash_EnumNext(&search))
        free(Hash_GetValue(entry));

    free(a->name);
    free(a->fnametab);
    Hash_DeleteTable(&a->members);
    free(a);
}
#endif


/*-
 *-----------------------------------------------------------------------
 * Arch_ParseArchive --
 *      Parse the archive specification in the given line and find/create
 *      the nodes for the specified archive members, placing their nodes
 *      on the given list.
 *
 * Input:
 *      linePtr         Pointer to start of specification
 *      nodeLst         Lst on which to place the nodes
 *      ctxt            Context in which to expand variables
 *
 * Results:
 *      TRUE if it was a valid specification. The linePtr is updated
 *      to point to the first non-space after the archive spec. The
 *      nodes for the members are placed on the given list.
 *-----------------------------------------------------------------------
 */
Boolean
Arch_ParseArchive(char **linePtr, Lst nodeLst, GNode *ctxt)
{
    char            *cp;            /* Pointer into line */
    GNode           *gn;            /* New node */
    char            *libName;       /* Library-part of specification */
    char            *memName;       /* Member-part of specification */
    char            saveChar;       /* Ending delimiter of member-name */
    Boolean         subLibName;     /* TRUE if libName should have/had
                                     * variable substitution performed on it */

    libName = *linePtr;

    subLibName = FALSE;

    for (cp = libName; *cp != '(' && *cp != '\0'; cp++) {
        if (*cp == '$') {
            /*
             * Variable spec, so call the Var module to parse the puppy
             * so we can safely advance beyond it...
             */
            int         length;
            void        *result_freeIt;
            const char  *result;
            Boolean isError;

            result = Var_Parse(cp, ctxt, VARE_UNDEFERR|VARE_WANTRES,
                               &length, &result_freeIt);
            isError = result == var_Error;
            free(result_freeIt);
            if (isError)
                return FALSE;

            subLibName = TRUE;
            cp += length - 1;
        }
    }

    *cp++ = '\0';
    if (subLibName) {
        libName = Var_Subst(libName, ctxt, VARE_UNDEFERR|VARE_WANTRES);
    }


    for (;;) {
        /*
         * First skip to the start of the member's name, mark that
         * place and skip to the end of it (either white-space or
         * a close paren).
         */
        Boolean doSubst = FALSE; /* TRUE if need to substitute in memName */

        while (*cp != '\0' && *cp != ')' && isspace ((unsigned char)*cp)) {
            cp++;
        }
        memName = cp;
        while (*cp != '\0' && *cp != ')' && !isspace ((unsigned char)*cp)) {
            if (*cp == '$') {
                /*
                 * Variable spec, so call the Var module to parse the puppy
                 * so we can safely advance beyond it...
                 */
                int     length;
                void    *freeIt;
                const char *result;
                Boolean isError;

                result = Var_Parse(cp, ctxt, VARE_UNDEFERR|VARE_WANTRES,
                                   &length, &freeIt);
                isError = result == var_Error;
                free(freeIt);

                if (isError)
                    return FALSE;

                doSubst = TRUE;
                cp += length;
            } else {
                cp++;
            }
        }

        /*
         * If the specification ends without a closing parenthesis,
         * chances are there's something wrong (like a missing backslash),
         * so it's better to return failure than allow such things to happen
         */
        if (*cp == '\0') {
            printf("No closing parenthesis in archive specification\n");
            return FALSE;
        }

        /*
         * If we didn't move anywhere, we must be done
         */
        if (cp == memName) {
            break;
        }

        saveChar = *cp;
        *cp = '\0';

        /*
         * XXX: This should be taken care of intelligently by
         * SuffExpandChildren, both for the archive and the member portions.
         */
        /*
         * If member contains variables, try and substitute for them.
         * This will slow down archive specs with dynamic sources, of course,
         * since we'll be (non-)substituting them three times, but them's
         * the breaks -- we need to do this since SuffExpandChildren calls
         * us, otherwise we could assume the thing would be taken care of
         * later.
         */
        if (doSubst) {
            char    *buf;
            char    *sacrifice;
            char    *oldMemName = memName;

            memName = Var_Subst(memName, ctxt, VARE_UNDEFERR | VARE_WANTRES);

            /*
             * Now form an archive spec and recurse to deal with nested
             * variables and multi-word variable values.... The results
             * are just placed at the end of the nodeLst we're returning.
             */
            buf = sacrifice = str_concat4(libName, "(", memName, ")");

            if (strchr(memName, '$') && strcmp(memName, oldMemName) == 0) {
                /*
                 * Must contain dynamic sources, so we can't deal with it now.
                 * Just create an ARCHV node for the thing and let
                 * SuffExpandChildren handle it...
                 */
                gn = Targ_FindNode(buf, TARG_CREATE);

                if (gn == NULL) {
                    free(buf);
                    return FALSE;
                } else {
                    gn->type |= OP_ARCHV;
                    Lst_Append(nodeLst, gn);
                }
            } else if (!Arch_ParseArchive(&sacrifice, nodeLst, ctxt)) {
                /*
                 * Error in nested call -- free buffer and return FALSE
                 * ourselves.
                 */
                free(buf);
                return FALSE;
            }
            /*
             * Free buffer and continue with our work.
             */
            free(buf);
        } else if (Dir_HasWildcards(memName)) {
            Lst members = Lst_Init();
            Buffer nameBuf;

            Buf_Init(&nameBuf, 0);
            Dir_Expand(memName, dirSearchPath, members);
            while (!Lst_IsEmpty(members)) {
                char *member = Lst_Dequeue(members);

                Buf_Empty(&nameBuf);
                Buf_AddStr(&nameBuf, libName);
                Buf_AddStr(&nameBuf, "(");
                Buf_AddStr(&nameBuf, member);
                Buf_AddStr(&nameBuf, ")");
                free(member);

                gn = Targ_FindNode(Buf_GetAll(&nameBuf, NULL), TARG_CREATE);
                if (gn == NULL) {
                    Buf_Destroy(&nameBuf, TRUE);
                    return FALSE;
                } else {
                    /*
                     * We've found the node, but have to make sure the rest of
                     * the world knows it's an archive member, without having
                     * to constantly check for parentheses, so we type the
                     * thing with the OP_ARCHV bit before we place it on the
                     * end of the provided list.
                     */
                    gn->type |= OP_ARCHV;
                    Lst_Append(nodeLst, gn);
                }
            }
            Lst_Free(members);
            Buf_Destroy(&nameBuf, TRUE);
        } else {
            Buffer nameBuf;

            Buf_Init(&nameBuf, 0);
            Buf_AddStr(&nameBuf, libName);
            Buf_AddStr(&nameBuf, "(");
            Buf_AddStr(&nameBuf, memName);
            Buf_AddStr(&nameBuf, ")");

            gn = Targ_FindNode(Buf_GetAll(&nameBuf, NULL), TARG_CREATE);
            Buf_Destroy(&nameBuf, TRUE);
            if (gn == NULL) {
                return FALSE;
            } else {
                /*
                 * We've found the node, but have to make sure the rest of the
                 * world knows it's an archive member, without having to
                 * constantly check for parentheses, so we type the thing with
                 * the OP_ARCHV bit before we place it on the end of the
                 * provided list.
                 */
                gn->type |= OP_ARCHV;
                Lst_Append(nodeLst, gn);
            }
        }
        if (doSubst) {
            free(memName);
        }

        *cp = saveChar;
    }

    /*
     * If substituted libName, free it now, since we need it no longer.
     */
    if (subLibName) {
        free(libName);
    }

    /*
     * We promised the pointer would be set up at the next non-space, so
     * we must advance cp there before setting *linePtr... (note that on
     * entrance to the loop, cp is guaranteed to point at a ')')
     */
    do {
        cp++;
    } while (*cp != '\0' && isspace ((unsigned char)*cp));

    *linePtr = cp;
    return TRUE;
}

/* See if the given archive is the one we are looking for.
 * Called via Lst_Find. */
static Boolean
ArchFindArchive(const void *ar, const void *desiredName)
{
    return strcmp(((const Arch *)ar)->name, desiredName) == 0;
}

/*-
 *-----------------------------------------------------------------------
 * ArchStatMember --
 *      Locate a member of an archive, given the path of the archive and
 *      the path of the desired member.
 *
 * Input:
 *      archive         Path to the archive
 *      member          Name of member. If it is a path, only the last
 *                      component is used.
 *      hash            TRUE if archive should be hashed if not already so.
 *
 * Results:
 *      A pointer to the current struct ar_hdr structure for the member. Note
 *      That no position is returned, so this is not useful for touching
 *      archive members. This is mostly because we have no assurances that
 *      The archive will remain constant after we read all the headers, so
 *      there's not much point in remembering the position...
 *-----------------------------------------------------------------------
 */
static struct ar_hdr *
ArchStatMember(const char *archive, const char *member, Boolean hash)
{
    FILE *        arch;       /* Stream to archive */
    size_t        size;       /* Size of archive member */
    char          magic[SARMAG];
    LstNode       ln;         /* Lst member containing archive descriptor */
    Arch          *ar;        /* Archive descriptor */
    Hash_Entry    *he;        /* Entry containing member's description */
    struct ar_hdr arh;        /* archive-member header for reading archive */
    char          memName[MAXPATHLEN+1];
                            /* Current member name while hashing. */

    /*
     * Because of space constraints and similar things, files are archived
     * using their final path components, not the entire thing, so we need
     * to point 'member' to the final component, if there is one, to make
     * the comparisons easier...
     */
    const char *base = strrchr(member, '/');
    if (base != NULL) {
        member = base + 1;
    }

    ln = Lst_Find(archives, ArchFindArchive, archive);
    if (ln != NULL) {
        ar = LstNode_Datum(ln);

        he = Hash_FindEntry(&ar->members, member);

        if (he != NULL) {
            return (struct ar_hdr *)Hash_GetValue(he);
        } else {
            /* Try truncated name */
            char copy[AR_MAX_NAME_LEN+1];
            size_t len = strlen(member);

            if (len > AR_MAX_NAME_LEN) {
                len = AR_MAX_NAME_LEN;
                snprintf(copy, sizeof copy, "%s", member);
            }
            if ((he = Hash_FindEntry(&ar->members, copy)) != NULL)
                return (struct ar_hdr *)Hash_GetValue(he);
            return NULL;
        }
    }

    if (!hash) {
        /*
         * Caller doesn't want the thing hashed, just use ArchFindMember
         * to read the header for the member out and close down the stream
         * again. Since the archive is not to be hashed, we assume there's
         * no need to allocate extra room for the header we're returning,
         * so just declare it static.
         */
         static struct ar_hdr   sarh;

         arch = ArchFindMember(archive, member, &sarh, "r");

         if (arch == NULL) {
            return NULL;
        } else {
            fclose(arch);
            return &sarh;
        }
    }

    /*
     * We don't have this archive on the list yet, so we want to find out
     * everything that's in it and cache it so we can get at it quickly.
     */
    arch = fopen(archive, "r");
    if (arch == NULL) {
        return NULL;
    }

    /*
     * We use the ARMAG string to make sure this is an archive we
     * can handle...
     */
    if ((fread(magic, SARMAG, 1, arch) != 1) ||
        (strncmp(magic, ARMAG, SARMAG) != 0)) {
            fclose(arch);
            return NULL;
    }

    ar = bmake_malloc(sizeof(Arch));
    ar->name = bmake_strdup(archive);
    ar->fnametab = NULL;
    ar->fnamesize = 0;
    Hash_InitTable(&ar->members, -1);
    memName[AR_MAX_NAME_LEN] = '\0';

    while (fread((char *)&arh, sizeof(struct ar_hdr), 1, arch) == 1) {
        if (strncmp( arh.AR_FMAG, ARFMAG, sizeof(arh.AR_FMAG)) != 0) {
            /*
             * The header is bogus, so the archive is bad
             * and there's no way we can recover...
             */
            goto badarch;
        } else {
            char *nameend;

            /*
             * We need to advance the stream's pointer to the start of the
             * next header. Files are padded with newlines to an even-byte
             * boundary, so we need to extract the size of the file from the
             * 'size' field of the header and round it up during the seek.
             */
            arh.AR_SIZE[sizeof(arh.AR_SIZE)-1] = '\0';
            size = (size_t)strtol(arh.ar_size, NULL, 10);

            memcpy(memName, arh.AR_NAME, sizeof(arh.AR_NAME));
            nameend = memName + AR_MAX_NAME_LEN;
            while (*nameend == ' ') {
                nameend--;
            }
            nameend[1] = '\0';

#ifdef SVR4ARCHIVES
            /*
             * svr4 names are slash terminated. Also svr4 extended AR format.
             */
            if (memName[0] == '/') {
                /*
                 * svr4 magic mode; handle it
                 */
                switch (ArchSVR4Entry(ar, memName, size, arch)) {
                case -1:  /* Invalid data */
                    goto badarch;
                case 0:   /* List of files entry */
                    continue;
                default:  /* Got the entry */
                    break;
                }
            }
            else {
                if (nameend[0] == '/')
                    nameend[0] = '\0';
            }
#endif

#ifdef AR_EFMT1
            /*
             * BSD 4.4 extended AR format: #1/<namelen>, with name as the
             * first <namelen> bytes of the file
             */
            if (strncmp(memName, AR_EFMT1, sizeof(AR_EFMT1) - 1) == 0 &&
                isdigit((unsigned char)memName[sizeof(AR_EFMT1) - 1])) {

                int elen = atoi(&memName[sizeof(AR_EFMT1)-1]);

                if ((unsigned int)elen > MAXPATHLEN)
                        goto badarch;
                if (fread(memName, (size_t)elen, 1, arch) != 1)
                        goto badarch;
                memName[elen] = '\0';
                if (fseek(arch, -elen, SEEK_CUR) != 0)
                        goto badarch;
                if (DEBUG(ARCH) || DEBUG(MAKE)) {
                    fprintf(debug_file, "ArchStat: Extended format entry for %s\n", memName);
                }
            }
#endif

            he = Hash_CreateEntry(&ar->members, memName, NULL);
            Hash_SetValue(he, bmake_malloc(sizeof(struct ar_hdr)));
            memcpy(Hash_GetValue(he), &arh, sizeof(struct ar_hdr));
        }
        if (fseek(arch, ((long)size + 1) & ~1, SEEK_CUR) != 0)
            goto badarch;
    }

    fclose(arch);

    Lst_Append(archives, ar);

    /*
     * Now that the archive has been read and cached, we can look into
     * the hash table to find the desired member's header.
     */
    he = Hash_FindEntry(&ar->members, member);

    if (he != NULL) {
        return (struct ar_hdr *)Hash_GetValue(he);
    } else {
        return NULL;
    }

badarch:
    fclose(arch);
    Hash_DeleteTable(&ar->members);
    free(ar->fnametab);
    free(ar);
    return NULL;
}

#ifdef SVR4ARCHIVES
/*-
 *-----------------------------------------------------------------------
 * ArchSVR4Entry --
 *      Parse an SVR4 style entry that begins with a slash.
 *      If it is "//", then load the table of filenames
 *      If it is "/<offset>", then try to substitute the long file name
 *      from offset of a table previously read.
 *      If a table is read, the file pointer is moved to the next archive
 *      member.
 *
 * Results:
 *      -1: Bad data in archive
 *       0: A table was loaded from the file
 *       1: Name was successfully substituted from table
 *       2: Name was not successfully substituted from table
 *-----------------------------------------------------------------------
 */
static int
ArchSVR4Entry(Arch *ar, char *name, size_t size, FILE *arch)
{
#define ARLONGNAMES1 "//"
#define ARLONGNAMES2 "/ARFILENAMES"
    size_t entry;
    char *ptr, *eptr;

    if (strncmp(name, ARLONGNAMES1, sizeof(ARLONGNAMES1) - 1) == 0 ||
        strncmp(name, ARLONGNAMES2, sizeof(ARLONGNAMES2) - 1) == 0) {

        if (ar->fnametab != NULL) {
            if (DEBUG(ARCH)) {
                fprintf(debug_file, "Attempted to redefine an SVR4 name table\n");
            }
            return -1;
        }

        /*
         * This is a table of archive names, so we build one for
         * ourselves
         */
        ar->fnametab = bmake_malloc(size);
        ar->fnamesize = size;

        if (fread(ar->fnametab, size, 1, arch) != 1) {
            if (DEBUG(ARCH)) {
                fprintf(debug_file, "Reading an SVR4 name table failed\n");
            }
            return -1;
        }
        eptr = ar->fnametab + size;
        for (entry = 0, ptr = ar->fnametab; ptr < eptr; ptr++)
            switch (*ptr) {
            case '/':
                entry++;
                *ptr = '\0';
                break;

            case '\n':
                break;

            default:
                break;
            }
        if (DEBUG(ARCH)) {
            fprintf(debug_file, "Found svr4 archive name table with %lu entries\n",
                    (unsigned long)entry);
        }
        return 0;
    }

    if (name[1] == ' ' || name[1] == '\0')
        return 2;

    entry = (size_t)strtol(&name[1], &eptr, 0);
    if ((*eptr != ' ' && *eptr != '\0') || eptr == &name[1]) {
        if (DEBUG(ARCH)) {
            fprintf(debug_file, "Could not parse SVR4 name %s\n", name);
        }
        return 2;
    }
    if (entry >= ar->fnamesize) {
        if (DEBUG(ARCH)) {
            fprintf(debug_file, "SVR4 entry offset %s is greater than %lu\n",
                   name, (unsigned long)ar->fnamesize);
        }
        return 2;
    }

    if (DEBUG(ARCH)) {
        fprintf(debug_file, "Replaced %s with %s\n", name, &ar->fnametab[entry]);
    }

    snprintf(name, MAXPATHLEN + 1, "%s", &ar->fnametab[entry]);
    return 1;
}
#endif


/*-
 *-----------------------------------------------------------------------
 * ArchFindMember --
 *      Locate a member of an archive, given the path of the archive and
 *      the path of the desired member. If the archive is to be modified,
 *      the mode should be "r+", if not, it should be "r".
 *      The passed struct ar_hdr structure is filled in.
 *
 * Input:
 *      archive         Path to the archive
 *      member          Name of member. If it is a path, only the last
 *                      component is used.
 *      arhPtr          Pointer to header structure to be filled in
 *      mode            The mode for opening the stream
 *
 * Results:
 *      An FILE *, opened for reading and writing, positioned at the
 *      start of the member's struct ar_hdr, or NULL if the member was
 *      nonexistent. The current struct ar_hdr for member.
 *-----------------------------------------------------------------------
 */
static FILE *
ArchFindMember(const char *archive, const char *member, struct ar_hdr *arhPtr,
    const char *mode)
{
    FILE *        arch;       /* Stream to archive */
    int           size;       /* Size of archive member */
    char          magic[SARMAG];
    size_t        len, tlen;
    const char *  base;

    arch = fopen(archive, mode);
    if (arch == NULL) {
        return NULL;
    }

    /*
     * We use the ARMAG string to make sure this is an archive we
     * can handle...
     */
    if ((fread(magic, SARMAG, 1, arch) != 1) ||
        (strncmp(magic, ARMAG, SARMAG) != 0)) {
            fclose(arch);
            return NULL;
    }

    /*
     * Because of space constraints and similar things, files are archived
     * using their final path components, not the entire thing, so we need
     * to point 'member' to the final component, if there is one, to make
     * the comparisons easier...
     */
    base = strrchr(member, '/');
    if (base != NULL) {
        member = base + 1;
    }
    len = tlen = strlen(member);
    if (len > sizeof(arhPtr->AR_NAME)) {
        tlen = sizeof(arhPtr->AR_NAME);
    }

    while (fread((char *)arhPtr, sizeof(struct ar_hdr), 1, arch) == 1) {
        if (strncmp(arhPtr->AR_FMAG, ARFMAG, sizeof(arhPtr->AR_FMAG) ) != 0) {
             /*
              * The header is bogus, so the archive is bad
              * and there's no way we can recover...
              */
             fclose(arch);
             return NULL;
        } else if (strncmp(member, arhPtr->AR_NAME, tlen) == 0) {
            /*
             * If the member's name doesn't take up the entire 'name' field,
             * we have to be careful of matching prefixes. Names are space-
             * padded to the right, so if the character in 'name' at the end
             * of the matched string is anything but a space, this isn't the
             * member we sought.
             */
            if (tlen != sizeof(arhPtr->AR_NAME) && arhPtr->AR_NAME[tlen] != ' '){
                goto skip;
            } else {
                /*
                 * To make life easier, we reposition the file at the start
                 * of the header we just read before we return the stream.
                 * In a more general situation, it might be better to leave
                 * the file at the actual member, rather than its header, but
                 * not here...
                 */
                if (fseek(arch, -(long)sizeof(struct ar_hdr), SEEK_CUR) != 0) {
                    fclose(arch);
                    return NULL;
                }
                return arch;
            }
        } else
#ifdef AR_EFMT1
                /*
                 * BSD 4.4 extended AR format: #1/<namelen>, with name as the
                 * first <namelen> bytes of the file
                 */
            if (strncmp(arhPtr->AR_NAME, AR_EFMT1,
                                        sizeof(AR_EFMT1) - 1) == 0 &&
                isdigit((unsigned char)arhPtr->AR_NAME[sizeof(AR_EFMT1) - 1])) {

                int elen = atoi(&arhPtr->AR_NAME[sizeof(AR_EFMT1)-1]);
                char ename[MAXPATHLEN + 1];

                if ((unsigned int)elen > MAXPATHLEN) {
                        fclose(arch);
                        return NULL;
                }
                if (fread(ename, (size_t)elen, 1, arch) != 1) {
                        fclose(arch);
                        return NULL;
                }
                ename[elen] = '\0';
                if (DEBUG(ARCH) || DEBUG(MAKE)) {
                    fprintf(debug_file, "ArchFind: Extended format entry for %s\n", ename);
                }
                if (strncmp(ename, member, len) == 0) {
                        /* Found as extended name */
                        if (fseek(arch, -(long)sizeof(struct ar_hdr) - elen,
                                SEEK_CUR) != 0) {
                            fclose(arch);
                            return NULL;
                        }
                        return arch;
                }
                if (fseek(arch, -elen, SEEK_CUR) != 0) {
                    fclose(arch);
                    return NULL;
                }
                goto skip;
        } else
#endif
        {
skip:
            /*
             * This isn't the member we're after, so we need to advance the
             * stream's pointer to the start of the next header. Files are
             * padded with newlines to an even-byte boundary, so we need to
             * extract the size of the file from the 'size' field of the
             * header and round it up during the seek.
             */
            arhPtr->AR_SIZE[sizeof(arhPtr->AR_SIZE)-1] = '\0';
            size = (int)strtol(arhPtr->AR_SIZE, NULL, 10);
            if (fseek(arch, (size + 1) & ~1, SEEK_CUR) != 0) {
                fclose(arch);
                return NULL;
            }
        }
    }

    /*
     * We've looked everywhere, but the member is not to be found. Close the
     * archive and return NULL -- an error.
     */
    fclose(arch);
    return NULL;
}

/*-
 *-----------------------------------------------------------------------
 * Arch_Touch --
 *      Touch a member of an archive.
 *      The modification time of the entire archive is also changed.
 *      For a library, this could necessitate the re-ranlib'ing of the
 *      whole thing.
 *
 * Input:
 *      gn              Node of member to touch
 *
 * Results:
 *      The 'time' field of the member's header is updated.
 *-----------------------------------------------------------------------
 */
void
Arch_Touch(GNode *gn)
{
    FILE *        arch;   /* Stream open to archive, positioned properly */
    struct ar_hdr arh;    /* Current header describing member */
    char *p1, *p2;

    arch = ArchFindMember(Var_Value(ARCHIVE, gn, &p1),
                          Var_Value(MEMBER, gn, &p2),
                          &arh, "r+");

    bmake_free(p1);
    bmake_free(p2);

    snprintf(arh.AR_DATE, sizeof(arh.AR_DATE), "%-12ld", (long) now);

    if (arch != NULL) {
        (void)fwrite((char *)&arh, sizeof(struct ar_hdr), 1, arch);
        fclose(arch);
    }
}

/* Given a node which represents a library, touch the thing, making sure that
 * the table of contents also is touched.
 *
 * Both the modification time of the library and of the RANLIBMAG member are
 * set to 'now'.
 *
 * Input:
 *      gn              The node of the library to touch
 */
void
Arch_TouchLib(GNode *gn)
{
#ifdef RANLIBMAG
    FILE *          arch;       /* Stream open to archive */
    struct ar_hdr   arh;        /* Header describing table of contents */
    struct utimbuf  times;      /* Times for utime() call */

    arch = ArchFindMember(gn->path, RANLIBMAG, &arh, "r+");
    snprintf(arh.AR_DATE, sizeof(arh.AR_DATE), "%-12ld", (long) now);

    if (arch != NULL) {
        (void)fwrite((char *)&arh, sizeof(struct ar_hdr), 1, arch);
        fclose(arch);

        times.actime = times.modtime = now;
        utime(gn->path, &times);
    }
#else
    (void)gn;
#endif
}

/* Return the modification time of a member of an archive. The mtime field
 * of the given node is filled in with the value returned by the function.
 *
 * Input:
 *      gn              Node describing archive member
 */
time_t
Arch_MTime(GNode *gn)
{
    struct ar_hdr *arhPtr;    /* Header of desired member */
    time_t        modTime;    /* Modification time as an integer */
    char *p1, *p2;

    arhPtr = ArchStatMember(Var_Value(ARCHIVE, gn, &p1),
                             Var_Value(MEMBER, gn, &p2),
                             TRUE);

    bmake_free(p1);
    bmake_free(p2);

    if (arhPtr != NULL) {
        modTime = (time_t)strtol(arhPtr->AR_DATE, NULL, 10);
    } else {
        modTime = 0;
    }

    gn->mtime = modTime;
    return modTime;
}

/* Given a non-existent archive member's node, get its modification time from
 * its archived form, if it exists. gn->mtime is filled in as well. */
time_t
Arch_MemMTime(GNode *gn)
{
    LstNode       ln;
    GNode         *pgn;

    Lst_Open(gn->parents);
    while ((ln = Lst_Next(gn->parents)) != NULL) {
        pgn = LstNode_Datum(ln);

        if (pgn->type & OP_ARCHV) {
            /*
             * If the parent is an archive specification and is being made
             * and its member's name matches the name of the node we were
             * given, record the modification time of the parent in the
             * child. We keep searching its parents in case some other
             * parent requires this child to exist...
             */
            const char *nameStart = strchr(pgn->name, '(') + 1;
            const char *nameEnd = strchr(nameStart, ')');
            size_t nameLen = (size_t)(nameEnd - nameStart);

            if ((pgn->flags & REMAKE) &&
                strncmp(nameStart, gn->name, nameLen) == 0) {
                gn->mtime = Arch_MTime(pgn);
            }
        } else if (pgn->flags & REMAKE) {
            /*
             * Something which isn't a library depends on the existence of
             * this target, so it needs to exist.
             */
            gn->mtime = 0;
            break;
        }
    }

    Lst_Close(gn->parents);

    return gn->mtime;
}

/* Search for a library along the given search path.
 *
 * The node's 'path' field is set to the found path (including the
 * actual file name, not -l...). If the system can handle the -L
 * flag when linking (or we cannot find the library), we assume that
 * the user has placed the .LIBS variable in the final linking
 * command (or the linker will know where to find it) and set the
 * TARGET variable for this node to be the node's name. Otherwise,
 * we set the TARGET variable to be the full path of the library,
 * as returned by Dir_FindFile.
 *
 * Input:
 *      gn              Node of library to find
 *      path            Search path
 */
void
Arch_FindLib(GNode *gn, Lst path)
{
    char            *libName;   /* file name for archive */
    size_t           sz = strlen(gn->name) + 6 - 2;

    libName = bmake_malloc(sz);
    snprintf(libName, sz, "lib%s.a", &gn->name[2]);

    gn->path = Dir_FindFile(libName, path);

    free(libName);

#ifdef LIBRARIES
    Var_Set(TARGET, gn->name, gn);
#else
    Var_Set(TARGET, gn->path == NULL ? gn->name : gn->path, gn);
#endif /* LIBRARIES */
}

/* Decide if a node with the OP_LIB attribute is out-of-date. Called from
 * Make_OODate to make its life easier.
 * The library will be hashed if it hasn't been already.
 *
 * There are several ways for a library to be out-of-date that are
 * not available to ordinary files. In addition, there are ways
 * that are open to regular files that are not available to
 * libraries. A library that is only used as a source is never
 * considered out-of-date by itself. This does not preclude the
 * library's modification time from making its parent be out-of-date.
 * A library will be considered out-of-date for any of these reasons,
 * given that it is a target on a dependency line somewhere:
 *
 *      Its modification time is less than that of one of its sources
 *      (gn->mtime < gn->cmgn->mtime).
 *
 *      Its modification time is greater than the time at which the make
 *      began (i.e. it's been modified in the course of the make, probably
 *      by archiving).
 *
 *      The modification time of one of its sources is greater than the one
 *      of its RANLIBMAG member (i.e. its table of contents is out-of-date).
 *      We don't compare of the archive time vs. TOC time because they can be
 *      too close. In my opinion we should not bother with the TOC at all
 *      since this is used by 'ar' rules that affect the data contents of the
 *      archive, not by ranlib rules, which affect the TOC.
 *
 * Input:
 *      gn              The library's graph node
 *
 * Results:
 *      TRUE if the library is out-of-date. FALSE otherwise.
 */
Boolean
Arch_LibOODate(GNode *gn)
{
    Boolean       oodate;

    if (gn->type & OP_PHONY) {
        oodate = TRUE;
    } else if (OP_NOP(gn->type) && Lst_IsEmpty(gn->children)) {
        oodate = FALSE;
    } else if ((!Lst_IsEmpty(gn->children) && gn->cmgn == NULL) ||
               (gn->mtime > now) ||
               (gn->cmgn != NULL && gn->mtime < gn->cmgn->mtime)) {
        oodate = TRUE;
    } else {
#ifdef RANLIBMAG
        struct ar_hdr   *arhPtr;    /* Header for __.SYMDEF */
        int             modTimeTOC; /* The table-of-contents's mod time */

        arhPtr = ArchStatMember(gn->path, RANLIBMAG, FALSE);

        if (arhPtr != NULL) {
            modTimeTOC = (int)strtol(arhPtr->AR_DATE, NULL, 10);

            if (DEBUG(ARCH) || DEBUG(MAKE)) {
                fprintf(debug_file, "%s modified %s...", RANLIBMAG, Targ_FmtTime(modTimeTOC));
            }
            oodate = (gn->cmgn == NULL || gn->cmgn->mtime > modTimeTOC);
        } else {
            /*
             * A library w/o a table of contents is out-of-date
             */
            if (DEBUG(ARCH) || DEBUG(MAKE)) {
                fprintf(debug_file, "No t.o.c....");
            }
            oodate = TRUE;
        }
#else
        oodate = FALSE;
#endif
    }
    return oodate;
}

/* Initialize things for this module. */
void
Arch_Init(void)
{
    archives = Lst_Init();
}

/* Clean up things for this module. */
void
Arch_End(void)
{
#ifdef CLEANUP
    Lst_Destroy(archives, ArchFree);
#endif
}

Boolean
Arch_IsLib(GNode *gn)
{
    static const char armag[] = "!<arch>\n";
    char buf[sizeof armag - 1];
    int fd;

    if ((fd = open(gn->path, O_RDONLY)) == -1)
        return FALSE;

    if (read(fd, buf, sizeof buf) != sizeof buf) {
        (void)close(fd);
        return FALSE;
    }

    (void)close(fd);

    return memcmp(buf, armag, sizeof buf) == 0;
}