nasmlib.c

nasm早期的源代码,比较简单是学习汇编和编译原理的好例子

/* nasmlib.c	library routines for the Netwide Assembler
 *
 * The Netwide Assembler is copyright (C) 1996 Simon Tatham and
 * Julian Hall. All rights reserved. The software is
 * redistributable under the licence given in the file "Licence"
 * distributed in the NASM archive.
 */

#include "compiler.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <inttypes.h>

#include "nasm.h"
#include "nasmlib.h"
#include "insns.h"

int globalbits = 0;    /* defined in nasm.h, works better here for ASM+DISASM */
efunc nasm_malloc_error;	/* Exported for the benefit of vsnprintf.c */

#ifdef LOGALLOC
static FILE *logfp;
#endif

void nasm_set_malloc_error(efunc error)
{
    nasm_malloc_error = error;
#ifdef LOGALLOC
    logfp = fopen("malloc.log", "w");
    setvbuf(logfp, NULL, _IOLBF, BUFSIZ);
    fprintf(logfp, "null pointer is %p\n", NULL);
#endif
}

#ifdef LOGALLOC
void *nasm_malloc_log(char *file, int line, size_t size)
#else
void *nasm_malloc(size_t size)
#endif
{
    void *p = malloc(size);
    if (!p)
        nasm_malloc_error(ERR_FATAL | ERR_NOFILE, "out of memory");
#ifdef LOGALLOC
    else
        fprintf(logfp, "%s %d malloc(%ld) returns %p\n",
                file, line, (long)size, p);
#endif
    return p;
}

#ifdef LOGALLOC
void *nasm_zalloc_log(char *file, int line, size_t size)
#else
void *nasm_zalloc(size_t size)
#endif
{
    void *p = calloc(size, 1);
    if (!p)
        nasm_malloc_error(ERR_FATAL | ERR_NOFILE, "out of memory");
#ifdef LOGALLOC
    else
        fprintf(logfp, "%s %d calloc(%ld, 1) returns %p\n",
                file, line, (long)size, p);
#endif
    return p;
}

#ifdef LOGALLOC
void *nasm_realloc_log(char *file, int line, void *q, size_t size)
#else
void *nasm_realloc(void *q, size_t size)
#endif
{
    void *p = q ? realloc(q, size) : malloc(size);
    if (!p)
        nasm_malloc_error(ERR_FATAL | ERR_NOFILE, "out of memory");
#ifdef LOGALLOC
    else if (q)
        fprintf(logfp, "%s %d realloc(%p,%ld) returns %p\n",
                file, line, q, (long)size, p);
    else
        fprintf(logfp, "%s %d malloc(%ld) returns %p\n",
                file, line, (long)size, p);
#endif
    return p;
}

#ifdef LOGALLOC
void nasm_free_log(char *file, int line, void *q)
#else
void nasm_free(void *q)
#endif
{
    if (q) {
        free(q);
#ifdef LOGALLOC
        fprintf(logfp, "%s %d free(%p)\n", file, line, q);
#endif
    }
}

#ifdef LOGALLOC
char *nasm_strdup_log(char *file, int line, const char *s)
#else
char *nasm_strdup(const char *s)
#endif
{
    char *p;
    int size = strlen(s) + 1;

    p = malloc(size);
    if (!p)
        nasm_malloc_error(ERR_FATAL | ERR_NOFILE, "out of memory");
#ifdef LOGALLOC
    else
        fprintf(logfp, "%s %d strdup(%ld) returns %p\n",
                file, line, (long)size, p);
#endif
    strcpy(p, s);
    return p;
}

#ifdef LOGALLOC
char *nasm_strndup_log(char *file, int line, char *s, size_t len)
#else
char *nasm_strndup(char *s, size_t len)
#endif
{
    char *p;
    int size = len + 1;

    p = malloc(size);
    if (!p)
        nasm_malloc_error(ERR_FATAL | ERR_NOFILE, "out of memory");
#ifdef LOGALLOC
    else
        fprintf(logfp, "%s %d strndup(%ld) returns %p\n",
                file, line, (long)size, p);
#endif
    strncpy(p, s, len);
    p[len] = '\0';
    return p;
}

#ifndef nasm_stricmp
int nasm_stricmp(const char *s1, const char *s2)
{
    while (*s1 && tolower(*s1) == tolower(*s2))
        s1++, s2++;
    if (!*s1 && !*s2)
        return 0;
    else if (tolower(*s1) < tolower(*s2))
        return -1;
    else
        return 1;
}
#endif

#ifndef nasm_strnicmp
int nasm_strnicmp(const char *s1, const char *s2, int n)
{
    while (n > 0 && *s1 && tolower(*s1) == tolower(*s2))
        s1++, s2++, n--;
    if ((!*s1 && !*s2) || n == 0)
        return 0;
    else if (tolower(*s1) < tolower(*s2))
        return -1;
    else
        return 1;
}
#endif

#ifndef nasm_strsep
char *nasm_strsep(char **stringp, const char *delim)
{
        char *s = *stringp;
        char *e;

        if (!s)
                return NULL;

        e = strpbrk(s, delim);
        if (e)
                *e++ = '\0';

        *stringp = e;
        return s;
}
#endif


#define lib_isnumchar(c)   ( isalnum(c) || (c) == '$')
#define numvalue(c)  ((c)>='a' ? (c)-'a'+10 : (c)>='A' ? (c)-'A'+10 : (c)-'0')

int64_t readnum(char *str, bool *error)
{
    char *r = str, *q;
    int32_t radix;
    uint64_t result, checklimit;
    int digit, last;
    bool warn = false;
    int sign = 1;

    *error = false;

    while (isspace(*r))
        r++;                    /* find start of number */

    /*
     * If the number came from make_tok_num (as a result of an %assign), it
     * might have a '-' built into it (rather than in a preceeding token).
     */
    if (*r == '-') {
        r++;
        sign = -1;
    }

    q = r;

    while (lib_isnumchar(*q))
        q++;                    /* find end of number */

    /*
     * If it begins 0x, 0X or $, or ends in H, it's in hex. if it
     * ends in Q, it's octal. if it ends in B, it's binary.
     * Otherwise, it's ordinary decimal.
     */
    if (*r == '0' && (r[1] == 'x' || r[1] == 'X'))
        radix = 16, r += 2;
    else if (*r == '$')
        radix = 16, r++;
    else if (q[-1] == 'H' || q[-1] == 'h')
        radix = 16, q--;
    else if (q[-1] == 'Q' || q[-1] == 'q' || q[-1] == 'O' || q[-1] == 'o')
        radix = 8, q--;
    else if (q[-1] == 'B' || q[-1] == 'b' || q[-1] == 'Y' || q[-1] == 'y')
        radix = 2, q--;
    else if (q[-1] == 'D' || q[-1] == 'd' || q[-1] == 'T' || q[-1] == 't')
	radix = 10, q--;
    else
        radix = 10;

    /*
     * If this number has been found for us by something other than
     * the ordinary scanners, then it might be malformed by having
     * nothing between the prefix and the suffix. Check this case
     * now.
     */
    if (r >= q) {
        *error = true;
        return 0;
    }
    
    /*
     * `checklimit' must be 2**(32|64) / radix. We can't do that in
     * 32/64-bit arithmetic, which we're (probably) using, so we
     * cheat: since we know that all radices we use are even, we
     * can divide 2**(31|63) by radix/2 instead.
     */
    if (globalbits == 64)
        checklimit = 0x8000000000000000ULL / (radix >> 1);
    else
        checklimit = 0x80000000UL / (radix >> 1);

    /*
     * Calculate the highest allowable value for the last digit of a
     * 32-bit constant... in radix 10, it is 6, otherwise it is 0
     */
    last = (radix == 10 ? 6 : 0);

    result = 0;
    while (*r && r < q) {
        if (*r < '0' || (*r > '9' && *r < 'A')
            || (digit = numvalue(*r)) >= radix) {
            *error = true;
            return 0;
        }
        if (result > checklimit || (result == checklimit && digit >= last)) {
            warn = true;
        }

        result = radix * result + digit;
        r++;
    }

    if (warn)
        nasm_malloc_error(ERR_WARNING | ERR_PASS1 | ERR_WARN_NOV,
                          "numeric constant %s does not fit in 32 bits",
                          str);

    return result * sign;
}

int64_t readstrnum(char *str, int length, bool *warn)
{
    int64_t charconst = 0;
    int i;

    *warn = false;

    str += length;
    if (globalbits == 64) {
        for (i = 0; i < length; i++) {
            if (charconst & 0xFF00000000000000ULL)
                *warn = true;
            charconst = (charconst << 8) + (uint8_t)*--str;
        }
    } else {
        for (i = 0; i < length; i++) {
            if (charconst & 0xFF000000UL)
                *warn = true;
            charconst = (charconst << 8) + (uint8_t)*--str;
        }
    }
    return charconst;
}

static int32_t next_seg;

void seg_init(void)
{
    next_seg = 0;
}

int32_t seg_alloc(void)
{
    return (next_seg += 2) - 2;
}

void fwriteint16_t(int data, FILE * fp)
{
    fputc((int)(data & 255), fp);
    fputc((int)((data >> 8) & 255), fp);
}

void fwriteint32_t(int32_t data, FILE * fp)
{
    fputc((int)(data & 255), fp);
    fputc((int)((data >> 8) & 255), fp);
    fputc((int)((data >> 16) & 255), fp);
    fputc((int)((data >> 24) & 255), fp);
}

void fwriteint64_t(int64_t data, FILE * fp)
{
    fputc((int)(data & 255), fp);
    fputc((int)((data >> 8) & 255), fp);
    fputc((int)((data >> 16) & 255), fp);
    fputc((int)((data >> 24) & 255), fp);
    fputc((int)((data >> 32) & 255), fp);
    fputc((int)((data >> 40) & 255), fp);
    fputc((int)((data >> 48) & 255), fp);
    fputc((int)((data >> 56) & 255), fp);
}

void standard_extension(char *inname, char *outname, char *extension,
                        efunc error)
{
    char *p, *q;

    if (*outname)               /* file name already exists, */
        return;                 /* so do nothing */
    q = inname;
    p = outname;
    while (*q)
        *p++ = *q++;            /* copy, and find end of string */
    *p = '\0';                  /* terminate it */
    while (p > outname && *--p != '.') ;        /* find final period (or whatever) */
    if (*p != '.')
        while (*p)
            p++;                /* go back to end if none found */
    if (!strcmp(p, extension)) {        /* is the extension already there? */
        if (*extension)
            error(ERR_WARNING | ERR_NOFILE,
                  "file name already ends in `%s': "
                  "output will be in `nasm.out'", extension);
        else
            error(ERR_WARNING | ERR_NOFILE,
                  "file name already has no extension: "
                  "output will be in `nasm.out'");
        strcpy(outname, "nasm.out");
    } else
        strcpy(p, extension);
}

#define LEAFSIZ (sizeof(RAA)-sizeof(RAA_UNION)+sizeof(RAA_LEAF))
#define BRANCHSIZ (sizeof(RAA)-sizeof(RAA_UNION)+sizeof(RAA_BRANCH))

#define LAYERSIZ(r) ( (r)->layers==0 ? RAA_BLKSIZE : RAA_LAYERSIZE )

static struct RAA *real_raa_init(int layers)
{
    struct RAA *r;
    int i;

    if (layers == 0) {
        r = nasm_zalloc(LEAFSIZ);
        r->stepsize = 1L;
    } else {
        r = nasm_malloc(BRANCHSIZ);
        r->layers = layers;
        for (i = 0; i < RAA_LAYERSIZE; i++)
            r->u.b.data[i] = NULL;
        r->stepsize = RAA_BLKSIZE;
        while (--layers)
            r->stepsize *= RAA_LAYERSIZE;
    }
    return r;
}

struct RAA *raa_init(void)
{
    return real_raa_init(0);
}

void raa_free(struct RAA *r)
{
    if (r->layers == 0)
        nasm_free(r);
    else {
        struct RAA **p;
        for (p = r->u.b.data; p - r->u.b.data < RAA_LAYERSIZE; p++)
            if (*p)
                raa_free(*p);
    }
}

int32_t raa_read(struct RAA *r, int32_t posn)
{
    if (posn >= r->stepsize * LAYERSIZ(r))
        return 0;               /* Return 0 for undefined entries */
    while (r->layers > 0) {
        ldiv_t l;
        l = ldiv(posn, r->stepsize);
        r = r->u.b.data[l.quot];
        posn = l.rem;
        if (!r)
            return 0;           /* Return 0 for undefined entries */
    }
    return r->u.l.data[posn];
}

struct RAA *raa_write(struct RAA *r, int32_t posn, int32_t value)
{
    struct RAA *result;

    if (posn < 0)
        nasm_malloc_error(ERR_PANIC, "negative position in raa_write");

    while (r->stepsize * LAYERSIZ(r) <= posn) {
        /*