outcoff.c
资源名称:nasm-0.98.zip [点击查看]
上传用户:yuppie_zhu
上传日期:2007-01-08
资源大小:535k
文件大小:20k
源码类别:
编译器/解释器
开发平台:
C/C++
- /* outcoff.c output routines for the Netwide Assembler to produce
- * COFF object files (for DJGPP and Win32)
- *
- * 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 <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <ctype.h>
- #include <time.h>
- #include "nasm.h"
- #include "nasmlib.h"
- #include "outform.h"
- #if defined(OF_COFF) || defined(OF_WIN32)
- /*
- * Notes on COFF:
- *
- * (0) When I say `standard COFF' below, I mean `COFF as output and
- * used by DJGPP'. I assume DJGPP gets it right.
- *
- * (1) Win32 appears to interpret the term `relative relocation'
- * differently from standard COFF. Standard COFF understands a
- * relative relocation to mean that during relocation you add the
- * address of the symbol you're referencing, and subtract the base
- * address of the section you're in. Win32 COFF, by contrast, seems
- * to add the address of the symbol and then subtract the address
- * of THE BYTE AFTER THE RELOCATED DWORD. Hence the two formats are
- * subtly incompatible.
- *
- * (2) Win32 doesn't bother putting any flags in the header flags
- * field (at offset 0x12 into the file).
- *
- * (3) Win32 uses some extra flags into the section header table:
- * it defines flags 0x80000000 (writable), 0x40000000 (readable)
- * and 0x20000000 (executable), and uses them in the expected
- * combinations. It also defines 0x00100000 through 0x00700000 for
- * section alignments of 1 through 64 bytes.
- *
- * (4) Both standard COFF and Win32 COFF seem to use the DWORD
- * field directly after the section name in the section header
- * table for something strange: they store what the address of the
- * section start point _would_ be, if you laid all the sections end
- * to end starting at zero. Dunno why. Microsoft's documentation
- * lists this field as "Virtual Size of Section", which doesn't
- * seem to fit at all. In fact, Win32 even includes non-linked
- * sections such as .drectve in this calculation.
- *
- * (5) Standard COFF does something very strange to common
- * variables: the relocation point for a common variable is as far
- * _before_ the variable as its size stretches out _after_ it. So
- * we must fix up common variable references. Win32 seems to be
- * sensible on this one.
- */
- /* Flag which version of COFF we are currently outputting. */
- static int win32;
- struct Reloc {
- struct Reloc *next;
- long address; /* relative to _start_ of section */
- long symbol; /* symbol number */
- enum {
- SECT_SYMBOLS,
- ABS_SYMBOL,
- REAL_SYMBOLS
- } symbase; /* relocation for symbol number :) */
- int relative; /* TRUE or FALSE */
- };
- struct Symbol {
- char name[9];
- long strpos; /* string table position of name */
- int section; /* section number where it's defined
- * - in COFF codes, not NASM codes */
- int is_global; /* is it a global symbol or not? */
- long value; /* address, or COMMON variable size */
- };
- static FILE *coffp;
- static efunc error;
- static char coff_infile[FILENAME_MAX];
- struct Section {
- struct SAA *data;
- unsigned long len;
- int nrelocs;
- long index;
- struct Reloc *head, **tail;
- unsigned long flags; /* section flags */
- char name[9];
- long pos, relpos;
- };
- #define TEXT_FLAGS (win32 ? 0x60500020L : 0x20L)
- #define DATA_FLAGS (win32 ? 0xC0300040L : 0x40L)
- #define BSS_FLAGS (win32 ? 0xC0300080L : 0x80L)
- #define INFO_FLAGS 0x00100A00L
- #define SECT_DELTA 32
- static struct Section **sects;
- static int nsects, sectlen;
- static struct SAA *syms;
- static unsigned long nsyms;
- static long def_seg;
- static int initsym;
- static struct RAA *bsym, *symval;
- static struct SAA *strs;
- static unsigned long strslen;
- static void coff_gen_init(FILE *, efunc);
- static void coff_sect_write (struct Section *, unsigned char *,
- unsigned long);
- static void coff_write (void);
- static void coff_section_header (char *, long, long, long, long, int, long);
- static void coff_write_relocs (struct Section *);
- static void coff_write_symbols (void);
- static void coff_win32_init(FILE *fp, efunc errfunc,
- ldfunc ldef, evalfunc eval)
- {
- win32 = TRUE;
- (void) ldef; /* placate optimisers */
- coff_gen_init(fp, errfunc);
- }
- static void coff_std_init(FILE *fp, efunc errfunc, ldfunc ldef, evalfunc eval)
- {
- win32 = FALSE;
- (void) ldef; /* placate optimisers */
- coff_gen_init(fp, errfunc);
- }
- static void coff_gen_init(FILE *fp, efunc errfunc)
- {
- coffp = fp;
- error = errfunc;
- sects = NULL;
- nsects = sectlen = 0;
- syms = saa_init((long)sizeof(struct Symbol));
- nsyms = 0;
- bsym = raa_init();
- symval = raa_init();
- strs = saa_init(1L);
- strslen = 0;
- def_seg = seg_alloc();
- }
- static void coff_cleanup(int debuginfo)
- {
- struct Reloc *r;
- int i;
- (void) debuginfo;
- coff_write();
- fclose (coffp);
- for (i=0; i<nsects; i++) {
- if (sects[i]->data)
- saa_free (sects[i]->data);
- while (sects[i]->head) {
- r = sects[i]->head;
- sects[i]->head = sects[i]->head->next;
- nasm_free (r);
- }
- nasm_free (sects[i]);
- }
- nasm_free (sects);
- saa_free (syms);
- raa_free (bsym);
- raa_free (symval);
- saa_free (strs);
- }
- static int coff_make_section (char *name, unsigned long flags)
- {
- struct Section *s;
- s = nasm_malloc (sizeof(*s));
- if (flags != BSS_FLAGS)
- s->data = saa_init (1L);
- else
- s->data = NULL;
- s->head = NULL;
- s->tail = &s->head;
- s->len = 0;
- s->nrelocs = 0;
- if (!strcmp(name, ".text"))
- s->index = def_seg;
- else
- s->index = seg_alloc();
- strncpy (s->name, name, 8);
- s->name[8] = ' ';
- s->flags = flags;
- if (nsects >= sectlen)
- sects = nasm_realloc (sects, (sectlen += SECT_DELTA)*sizeof(*sects));
- sects[nsects++] = s;
- return nsects-1;
- }
- static long coff_section_names (char *name, int pass, int *bits)
- {
- char *p;
- unsigned long flags, align_and = ~0L, align_or = 0L;
- int i;
- /*
- * Default is 32 bits.
- */
- if (!name)
- *bits = 32;
- if (!name)
- return def_seg;
- p = name;
- while (*p && !isspace(*p)) p++;
- if (*p) *p++ = ' ';
- if (strlen(name) > 8) {
- error (ERR_WARNING, "COFF section names limited to 8 characters:"
- " truncating");
- name[8] = ' ';
- }
- flags = 0;
- while (*p && isspace(*p)) p++;
- while (*p) {
- char *q = p;
- while (*p && !isspace(*p)) p++;
- if (*p) *p++ = ' ';
- while (*p && isspace(*p)) p++;
- if (!nasm_stricmp(q, "code") || !nasm_stricmp(q, "text")) {
- flags = TEXT_FLAGS;
- } else if (!nasm_stricmp(q, "data")) {
- flags = DATA_FLAGS;
- } else if (!nasm_stricmp(q, "bss")) {
- flags = BSS_FLAGS;
- } else if (!nasm_stricmp(q, "info")) {
- if (win32)
- flags = INFO_FLAGS;
- else {
- flags = DATA_FLAGS; /* gotta do something */
- error (ERR_NONFATAL, "standard COFF does not support"
- " informational sections");
- }
- } else if (!nasm_strnicmp(q,"align=",6)) {
- if (!win32)
- error (ERR_NONFATAL, "standard COFF does not support"
- " section alignment specification");
- else {
- if (q[6+strspn(q+6,"0123456789")])
- error(ERR_NONFATAL, "argument to `align' is not numeric");
- else {
- unsigned int align = atoi(q+6);
- if (!align || ((align-1) & align))
- error(ERR_NONFATAL, "argument to `align' is not a"
- " power of two");
- else if (align > 64)
- error(ERR_NONFATAL, "Win32 cannot align sections"
- " to better than 64-byte boundaries");
- else {
- align_and = ~0x00F00000L;
- align_or = (align == 1 ? 0x00100000L :
- align == 2 ? 0x00200000L :
- align == 4 ? 0x00300000L :
- align == 8 ? 0x00400000L :
- align == 16 ? 0x00500000L :
- align == 32 ? 0x00600000L : 0x00700000L);
- }
- }
- }
- }
- }
- for (i=0; i<nsects; i++)
- if (!strcmp(name, sects[i]->name))
- break;
- if (i == nsects) {
- if (!flags) {
- if (!strcmp(name, ".data"))
- flags = DATA_FLAGS;
- else if (!strcmp(name, ".bss"))
- flags = BSS_FLAGS;
- else
- flags = TEXT_FLAGS;
- }
- i = coff_make_section (name, flags);
- if (flags)
- sects[i]->flags = flags;
- sects[i]->flags &= align_and;
- sects[i]->flags |= align_or;
- } else if (pass == 1) {
- if (flags)
- error (ERR_WARNING, "section attributes ignored on"
- " redeclaration of section `%s'", name);
- }
- return sects[i]->index;
- }
- static void coff_deflabel (char *name, long segment, long offset,
- int is_global, char *special)
- {
- int pos = strslen+4;
- struct Symbol *sym;
- if (special)
- error (ERR_NONFATAL, "binary format does not support any"
- " special symbol types");
- if (name[0] == '.' && name[1] == '.' && name[2] != '@') {
- error (ERR_NONFATAL, "unrecognised special symbol `%s'", name);
- return;
- }
- if (strlen(name) > 8) {
- saa_wbytes (strs, name, (long)(1+strlen(name)));
- strslen += 1+strlen(name);
- } else
- pos = -1;
- sym = saa_wstruct (syms);
- sym->strpos = pos;
- if (pos == -1)
- strcpy (sym->name, name);
- sym->is_global = !!is_global;
- if (segment == NO_SEG)
- sym->section = -1; /* absolute symbol */
- else {
- int i;
- sym->section = 0;
- for (i=0; i<nsects; i++)
- if (segment == sects[i]->index) {
- sym->section = i+1;
- break;
- }
- if (!sym->section)
- sym->is_global = TRUE;
- }
- if (is_global == 2)
- sym->value = offset;
- else
- sym->value = (sym->section == 0 ? 0 : offset);
- /*
- * define the references from external-symbol segment numbers
- * to these symbol records.
- */
- if (sym->section == 0)
- bsym = raa_write (bsym, segment, nsyms);
- if (segment != NO_SEG)
- symval = raa_write (symval, segment, sym->section ? 0 : sym->value);
- nsyms++;
- }
- static long coff_add_reloc (struct Section *sect, long segment,
- int relative)
- {
- struct Reloc *r;
- r = *sect->tail = nasm_malloc(sizeof(struct Reloc));
- sect->tail = &r->next;
- r->next = NULL;
- r->address = sect->len;
- if (segment == NO_SEG)
- r->symbol = 0, r->symbase = ABS_SYMBOL;
- else {
- int i;
- r->symbase = REAL_SYMBOLS;
- for (i=0; i<nsects; i++)
- if (segment == sects[i]->index) {
- r->symbol = i*2;
- r->symbase = SECT_SYMBOLS;
- break;
- }
- if (r->symbase == REAL_SYMBOLS)
- r->symbol = raa_read (bsym, segment);
- }
- r->relative = relative;
- sect->nrelocs++;
- /*
- * Return the fixup for standard COFF common variables.
- */
- if (r->symbase == REAL_SYMBOLS && !win32)
- return raa_read (symval, segment);
- else
- return 0;
- }
- static void coff_out (long segto, void *data, unsigned long type,
- long segment, long wrt)
- {
- struct Section *s;
- long realbytes = type & OUT_SIZMASK;
- unsigned char mydata[4], *p;
- int i;
- if (wrt != NO_SEG) {
- wrt = NO_SEG; /* continue to do _something_ */
- error (ERR_NONFATAL, "WRT not supported by COFF output formats");
- }
- type &= OUT_TYPMASK;
- /*
- * handle absolute-assembly (structure definitions)
- */
- if (segto == NO_SEG) {
- if (type != OUT_RESERVE)
- error (ERR_NONFATAL, "attempt to assemble code in [ABSOLUTE]"
- " space");
- return;
- }
- s = NULL;
- for (i=0; i<nsects; i++)
- if (segto == sects[i]->index) {
- s = sects[i];
- break;
- }
- if (!s) {
- int tempint; /* ignored */
- if (segto != coff_section_names (".text", 2, &tempint))
- error (ERR_PANIC, "strange segment conditions in COFF driver");
- else
- s = sects[nsects-1];
- }
- if (!s->data && type != OUT_RESERVE) {
- error(ERR_WARNING, "attempt to initialise memory in"
- " BSS section `%s': ignored", s->name);
- if (type == OUT_REL2ADR)
- realbytes = 2;
- else if (type == OUT_REL4ADR)
- realbytes = 4;
- s->len += realbytes;
- return;
- }
- if (type == OUT_RESERVE) {
- if (s->data) {
- error(ERR_WARNING, "uninitialised space declared in"
- " non-BSS section `%s': zeroing", s->name);
- coff_sect_write (s, NULL, realbytes);
- } else
- s->len += realbytes;
- } else if (type == OUT_RAWDATA) {
- if (segment != NO_SEG)
- error(ERR_PANIC, "OUT_RAWDATA with other than NO_SEG");
- coff_sect_write (s, data, realbytes);
- } else if (type == OUT_ADDRESS) {
- if (realbytes != 4 && (segment != NO_SEG || wrt != NO_SEG))
- error(ERR_NONFATAL, "COFF format does not support non-32-bit"
- " relocations");
- else {
- long fix = 0;
- if (segment != NO_SEG || wrt != NO_SEG) {
- if (wrt != NO_SEG) {
- error(ERR_NONFATAL, "COFF format does not support"
- " WRT types");
- } else if (segment % 2) {
- error(ERR_NONFATAL, "COFF format does not support"
- " segment base references");
- } else
- fix = coff_add_reloc (s, segment, FALSE);
- }
- p = mydata;
- WRITELONG (p, *(long *)data + fix);
- coff_sect_write (s, mydata, realbytes);
- }
- } else if (type == OUT_REL2ADR) {
- error(ERR_NONFATAL, "COFF format does not support 16-bit"
- " relocations");
- } else if (type == OUT_REL4ADR) {
- if (segment == segto)
- error(ERR_PANIC, "intra-segment OUT_REL4ADR");
- else if (segment == NO_SEG && win32)
- error(ERR_NONFATAL, "Win32 COFF does not correctly support"
- " relative references to absolute addresses");
- else {
- long fix = 0;
- if (segment != NO_SEG && segment % 2) {
- error(ERR_NONFATAL, "COFF format does not support"
- " segment base references");
- } else
- fix = coff_add_reloc (s, segment, TRUE);
- p = mydata;
- if (win32) {
- WRITELONG (p, *(long*)data + 4 - realbytes + fix);
- } else {
- WRITELONG (p, *(long*)data-(realbytes + s->len) + fix);
- }
- coff_sect_write (s, mydata, 4L);
- }
- }
- }
- static void coff_sect_write (struct Section *sect,
- unsigned char *data, unsigned long len)
- {
- saa_wbytes (sect->data, data, len);
- sect->len += len;
- }
- static int coff_directives (char *directive, char *value, int pass)
- {
- return 0;
- }
- static void coff_write (void)
- {
- long pos, sympos, vsize;
- int i;
- /*
- * Work out how big the file will get. Calculate the start of
- * the `real' symbols at the same time.
- */
- pos = 0x14 + 0x28 * nsects;
- initsym = 3; /* two for the file, one absolute */
- for (i=0; i<nsects; i++) {
- if (sects[i]->data) {
- sects[i]->pos = pos;
- pos += sects[i]->len;
- sects[i]->relpos = pos;
- pos += 10 * sects[i]->nrelocs;
- } else
- sects[i]->pos = sects[i]->relpos = 0L;
- initsym += 2; /* two for each section */
- }
- sympos = pos;
- /*
- * Output the COFF header.
- */
- fwriteshort (0x14C, coffp); /* MACHINE_i386 */
- fwriteshort (nsects, coffp); /* number of sections */
- fwritelong (time(NULL), coffp); /* time stamp */
- fwritelong (sympos, coffp);
- fwritelong (nsyms + initsym, coffp);
- fwriteshort (0, coffp); /* no optional header */
- /* Flags: 32-bit, no line numbers. Win32 doesn't even bother with them. */
- fwriteshort (win32 ? 0 : 0x104, coffp);
- /*
- * Output the section headers.
- */
- vsize = 0L;
- for (i=0; i<nsects; i++) {
- coff_section_header (sects[i]->name, vsize, sects[i]->len,
- sects[i]->pos, sects[i]->relpos,
- sects[i]->nrelocs, sects[i]->flags);
- vsize += sects[i]->len;
- }
- /*
- * Output the sections and their relocations.
- */
- for (i=0; i<nsects; i++)
- if (sects[i]->data) {
- saa_fpwrite (sects[i]->data, coffp);
- coff_write_relocs (sects[i]);
- }
- /*
- * Output the symbol and string tables.
- */
- coff_write_symbols();
- fwritelong (strslen+4, coffp); /* length includes length count */
- saa_fpwrite (strs, coffp);
- }
- static void coff_section_header (char *name, long vsize,
- long datalen, long datapos,
- long relpos, int nrelocs, long flags)
- {
- char padname[8];
- memset (padname, 0, 8);
- strncpy (padname, name, 8);
- fwrite (padname, 8, 1, coffp);
- fwritelong (vsize, coffp);
- fwritelong (0L, coffp); /* RVA/offset - we ignore */
- fwritelong (datalen, coffp);
- fwritelong (datapos, coffp);
- fwritelong (relpos, coffp);
- fwritelong (0L, coffp); /* no line numbers - we don't do 'em */
- fwriteshort (nrelocs, coffp);
- fwriteshort (0, coffp); /* again, no line numbers */
- fwritelong (flags, coffp);
- }
- static void coff_write_relocs (struct Section *s)
- {
- struct Reloc *r;
- for (r = s->head; r; r = r->next) {
- fwritelong (r->address, coffp);
- fwritelong (r->symbol + (r->symbase == REAL_SYMBOLS ? initsym :
- r->symbase == ABS_SYMBOL ? initsym-1 :
- r->symbase == SECT_SYMBOLS ? 2 : 0), coffp);
- /*
- * Strange: Microsoft's COFF documentation says 0x03 for an
- * absolute relocation, but both Visual C++ and DJGPP agree
- * that in fact it's 0x06. I'll use 0x06 until someone
- * argues.
- */
- fwriteshort (r->relative ? 0x14 : 0x06, coffp);
- }
- }
- static void coff_symbol (char *name, long strpos, long value,
- int section, int type, int aux)
- {
- char padname[8];
- if (name) {
- memset (padname, 0, 8);
- strncpy (padname, name, 8);
- fwrite (padname, 8, 1, coffp);
- } else {
- fwritelong (0L, coffp);
- fwritelong (strpos, coffp);
- }
- fwritelong (value, coffp);
- fwriteshort (section, coffp);
- fwriteshort (0, coffp);
- fputc (type, coffp);
- fputc (aux, coffp);
- }
- static void coff_write_symbols (void)
- {
- char filename[18];
- int i;
- /*
- * The `.file' record, and the file name auxiliary record.
- */
- coff_symbol (".file", 0L, 0L, -2, 0x67, 1);
- memset (filename, 0, 18);
- strncpy (filename, coff_infile, 18);
- fwrite (filename, 18, 1, coffp);
- /*
- * The section records, with their auxiliaries.
- */
- memset (filename, 0, 18); /* useful zeroed buffer */
- for (i=0; i<nsects; i++) {
- coff_symbol (sects[i]->name, 0L, 0L, i+1, 3, 1);
- fwritelong (sects[i]->len, coffp);
- fwriteshort (sects[i]->nrelocs, coffp);
- fwrite (filename, 12, 1, coffp);
- }
- /*
- * The absolute symbol, for relative-to-absolute relocations.
- */
- coff_symbol (".absolut", 0L, 0L, -1, 3, 0);
- /*
- * The real symbols.
- */
- saa_rewind (syms);
- for (i=0; i<nsyms; i++) {
- struct Symbol *sym = saa_rstruct (syms);
- coff_symbol (sym->strpos == -1 ? sym->name : NULL,
- sym->strpos, sym->value, sym->section,
- sym->is_global ? 2 : 3, 0);
- }
- }
- static long coff_segbase (long segment)
- {
- return segment;
- }
- static void coff_std_filename (char *inname, char *outname, efunc error)
- {
- strcpy(coff_infile, inname);
- standard_extension (inname, outname, ".o", error);
- }
- static void coff_win32_filename (char *inname, char *outname, efunc error)
- {
- strcpy(coff_infile, inname);
- standard_extension (inname, outname, ".obj", error);
- }
- static char *coff_stdmac[] = {
- "%define __SECT__ [section .text]",
- "%macro __NASM_CDecl__ 1",
- "%endmacro",
- NULL
- };
- static int coff_set_info(enum geninfo type, char **val)
- {
- return 0;
- }
- #endif /* defined(OF_COFF) || defined(OF_WIN32) */
- #ifdef OF_COFF
- struct ofmt of_coff = {
- "COFF (i386) object files (e.g. DJGPP for DOS)",
- "coff",
- NULL,
- null_debug_arr,
- &null_debug_form,
- coff_stdmac,
- coff_std_init,
- coff_set_info,
- coff_out,
- coff_deflabel,
- coff_section_names,
- coff_segbase,
- coff_directives,
- coff_std_filename,
- coff_cleanup
- };
- #endif
- #ifdef OF_WIN32
- struct ofmt of_win32 = {
- "Microsoft Win32 (i386) object files",
- "win32",
- NULL,
- null_debug_arr,
- &null_debug_form,
- coff_stdmac,
- coff_win32_init,
- coff_set_info,
- coff_out,
- coff_deflabel,
- coff_section_names,
- coff_segbase,
- coff_directives,
- coff_win32_filename,
- coff_cleanup
- };
- #endif