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nasm/output/outcoff.c
H. Peter Anvin fb2a2d6697 outcoff: add semi-generic pragma namespaces 
Recognize the semi-generic pragma namespaces "coff" and "win" for
the win32 and win64 backends.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2019-09-30 13:30:15 -07:00

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/* ----------------------------------------------------------------------- *
*
* Copyright 1996-2017 The NASM Authors - All Rights Reserved
* See the file AUTHORS included with the NASM distribution for
* the specific copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
*
* ----------------------------------------------------------------------- */
/*
* outcoff.c output routines for the Netwide Assembler to produce
* COFF object files (for DJGPP and Win32)
*/
#include "compiler.h"
#include "nctype.h"
#include <time.h>
#include "nasm.h"
#include "nasmlib.h"
#include "ilog2.h"
#include "error.h"
#include "saa.h"
#include "raa.h"
#include "eval.h"
#include "outform.h"
#include "outlib.h"
#include "pecoff.h"
#if defined(OF_COFF) || defined(OF_WIN32) || defined(OF_WIN64)
/*
* 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.
*
* Newer versions of MASM seem to have changed this to be zero, and
* that apparently matches the COFF spec, so go with that.
*
* (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. */
bool win32, win64;
static int32_t imagebase_sect;
#define WRT_IMAGEBASE "..imagebase"
/*
* Some common section flags by default
*/
#define TEXT_FLAGS_WIN \
(IMAGE_SCN_CNT_CODE | \
IMAGE_SCN_ALIGN_16BYTES | \
IMAGE_SCN_MEM_EXECUTE | \
IMAGE_SCN_MEM_READ)
#define TEXT_FLAGS_DOS \
(IMAGE_SCN_CNT_CODE)
#define DATA_FLAGS_WIN \
(IMAGE_SCN_CNT_INITIALIZED_DATA | \
IMAGE_SCN_ALIGN_4BYTES | \
IMAGE_SCN_MEM_READ | \
IMAGE_SCN_MEM_WRITE)
#define DATA_FLAGS_DOS \
(IMAGE_SCN_CNT_INITIALIZED_DATA)
#define BSS_FLAGS_WIN \
(IMAGE_SCN_CNT_UNINITIALIZED_DATA | \
IMAGE_SCN_ALIGN_4BYTES | \
IMAGE_SCN_MEM_READ | \
IMAGE_SCN_MEM_WRITE)
#define BSS_FLAGS_DOS \
(IMAGE_SCN_CNT_UNINITIALIZED_DATA)
#define RDATA_FLAGS_WIN \
(IMAGE_SCN_CNT_INITIALIZED_DATA | \
IMAGE_SCN_ALIGN_8BYTES | \
IMAGE_SCN_MEM_READ)
#define RDATA_FLAGS_DOS \
(IMAGE_SCN_CNT_INITIALIZED_DATA)
#define PDATA_FLAGS \
(IMAGE_SCN_CNT_INITIALIZED_DATA | \
IMAGE_SCN_ALIGN_4BYTES | \
IMAGE_SCN_MEM_READ)
#define XDATA_FLAGS \
(IMAGE_SCN_CNT_INITIALIZED_DATA | \
IMAGE_SCN_ALIGN_8BYTES | \
IMAGE_SCN_MEM_READ)
#define INFO_FLAGS \
(IMAGE_SCN_ALIGN_1BYTES | \
IMAGE_SCN_LNK_INFO | \
IMAGE_SCN_LNK_REMOVE)
#define TEXT_FLAGS ((win32 | win64) ? TEXT_FLAGS_WIN : TEXT_FLAGS_DOS)
#define DATA_FLAGS ((win32 | win64) ? DATA_FLAGS_WIN : DATA_FLAGS_DOS)
#define BSS_FLAGS ((win32 | win64) ? BSS_FLAGS_WIN : BSS_FLAGS_DOS)
#define RDATA_FLAGS ((win32 | win64) ? RDATA_FLAGS_WIN : RDATA_FLAGS_DOS)
#define SECT_DELTA 32
struct coff_Section **coff_sects;
static int sectlen;
int coff_nsects;
struct SAA *coff_syms;
uint32_t coff_nsyms;
static int32_t def_seg;
static int initsym;
static struct RAA *bsym, *symval;
struct SAA *coff_strs;
static uint32_t strslen;
static void coff_gen_init(void);
static void coff_sect_write(struct coff_Section *, const uint8_t *, uint32_t);
static void coff_write(void);
static void coff_section_header(char *, int32_t, int32_t, int32_t, int32_t, int32_t, int, int32_t);
static void coff_write_relocs(struct coff_Section *);
static void coff_write_symbols(void);
static void coff_win32_init(void)
{
win32 = true;
win64 = false;
coff_gen_init();
}
static void coff_win64_init(void)
{
win32 = false;
win64 = true;
coff_gen_init();
imagebase_sect = seg_alloc()+1;
backend_label(WRT_IMAGEBASE, imagebase_sect, 0);
}
static void coff_std_init(void)
{
win32 = win64 = false;
coff_gen_init();
}
static void coff_gen_init(void)
{
coff_sects = NULL;
coff_nsects = sectlen = 0;
coff_syms = saa_init(sizeof(struct coff_Symbol));
coff_nsyms = 0;
bsym = raa_init();
symval = raa_init();
coff_strs = saa_init(1);
strslen = 0;
def_seg = seg_alloc();
}
static void coff_cleanup(void)
{
struct coff_Reloc *r;
int i;
dfmt->cleanup();
coff_write();
for (i = 0; i < coff_nsects; i++) {
if (coff_sects[i]->data)
saa_free(coff_sects[i]->data);
while (coff_sects[i]->head) {
r = coff_sects[i]->head;
coff_sects[i]->head = coff_sects[i]->head->next;
nasm_free(r);
}
nasm_free(coff_sects[i]->name);
nasm_free(coff_sects[i]);
}
nasm_free(coff_sects);
saa_free(coff_syms);
raa_free(bsym);
raa_free(symval);
saa_free(coff_strs);
}
int coff_make_section(char *name, uint32_t flags)
{
struct coff_Section *s;
size_t namelen;
s = nasm_zalloc(sizeof(*s));
if (flags != BSS_FLAGS)
s->data = saa_init(1);
s->tail = &s->head;
if (!strcmp(name, ".text"))
s->index = def_seg;
else
s->index = seg_alloc();
s->namepos = -1;
namelen = strlen(name);
if (namelen > 8) {
if (win32 || win64) {
s->namepos = strslen + 4;
saa_wbytes(coff_strs, name, namelen + 1);
strslen += namelen + 1;
} else {
namelen = 8;
}
}
s->name = nasm_malloc(namelen + 1);
strncpy(s->name, name, namelen);
s->name[namelen] = '\0';
s->flags = flags;
if (coff_nsects >= sectlen) {
sectlen += SECT_DELTA;
coff_sects = nasm_realloc(coff_sects, sectlen * sizeof(*coff_sects));
}
coff_sects[coff_nsects++] = s;
return coff_nsects - 1;
}
static inline int32_t coff_sectalign_flags(unsigned int align)
{
return (ilog2_32(align) + 1) << 20;
}
static int32_t coff_section_names(char *name, int *bits)
{
char *p;
uint32_t flags, align_and = ~0L, align_or = 0L;
int i;
/*
* Set default bits.
*/
if (!name) {
if(win64)
*bits = 64;
else
*bits = 32;
return def_seg;
}
p = name;
while (*p && !nasm_isspace(*p))
p++;
if (*p)
*p++ = '\0';
if (strlen(name) > 8) {
if (!win32 && !win64) {
nasm_warn(WARN_OTHER, "COFF section names limited to 8 characters: truncating");
name[8] = '\0';
}
}
flags = 0;
while (*p && nasm_isspace(*p))
p++;
while (*p) {
char *q = p;
while (*p && !nasm_isspace(*p))
p++;
if (*p)
*p++ = '\0';
while (*p && nasm_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, "rdata")) {
if (win32 | win64)
flags = RDATA_FLAGS;
else {
flags = DATA_FLAGS; /* gotta do something */
nasm_nonfatal("standard COFF does not support"
" read-only data sections");
}
} else if (!nasm_stricmp(q, "bss")) {
flags = BSS_FLAGS;
} else if (!nasm_stricmp(q, "info")) {
if (win32 | win64)
flags = INFO_FLAGS;
else {
flags = DATA_FLAGS; /* gotta do something */
nasm_nonfatal("standard COFF does not support"
" informational sections");
}
} else if (!nasm_strnicmp(q, "align=", 6)) {
if (!(win32 | win64))
nasm_nonfatal("standard COFF does not support"
" section alignment specification");
else {
if (q[6 + strspn(q + 6, "0123456789")])
nasm_nonfatal("argument to `align' is not numeric");
else {
unsigned int align = atoi(q + 6);
if (!align || ((align - 1) & align))
nasm_nonfatal("argument to `align' is not a"
" power of two");
else if (align > 64)
nasm_nonfatal("Win32 cannot align sections"
" to better than 64-byte boundaries");
else {
align_and = ~0x00F00000L;
align_or = coff_sectalign_flags(align);
}
}
}
}
}
for (i = 0; i < coff_nsects; i++)
if (!strcmp(name, coff_sects[i]->name))
break;
if (i == coff_nsects) {
if (!flags) {
if (!strcmp(name, ".data"))
flags = DATA_FLAGS;
else if (!strcmp(name, ".rdata"))
flags = RDATA_FLAGS;
else if (!strcmp(name, ".bss"))
flags = BSS_FLAGS;
else if (win64 && !strcmp(name, ".pdata"))
flags = PDATA_FLAGS;
else if (win64 && !strcmp(name, ".xdata"))
flags = XDATA_FLAGS;
else
flags = TEXT_FLAGS;
}
i = coff_make_section(name, flags);
if (flags)
coff_sects[i]->flags = flags;
coff_sects[i]->flags &= align_and;
coff_sects[i]->flags |= align_or;
} else if (flags) {
/* Check if any flags are respecified */
unsigned int align_flags = flags & IMAGE_SCN_ALIGN_MASK;
/* Warn if non-alignment flags differ */
if ((flags ^ coff_sects[i]->flags) & ~IMAGE_SCN_ALIGN_MASK &&
coff_sects[i]->pass_last_seen == pass_count()) {
nasm_warn(WARN_OTHER, "section attributes changed on"
" redeclaration of section `%s'", name);
}
/* Check if alignment might be needed */
if (align_flags > IMAGE_SCN_ALIGN_1BYTES) {
unsigned int sect_align_flags = coff_sects[i]->flags & IMAGE_SCN_ALIGN_MASK;
/* Compute the actual alignment */
unsigned int align = 1u << ((align_flags - IMAGE_SCN_ALIGN_1BYTES) >> 20);
/* Update section header as needed */
if (align_flags > sect_align_flags) {
coff_sects[i]->flags = (coff_sects[i]->flags & ~IMAGE_SCN_ALIGN_MASK) | align_flags;
}
/* Check if not already aligned */
if (coff_sects[i]->len % align) {
unsigned int padding = (align - coff_sects[i]->len) % align;
/* We need to write at most 8095 bytes */
char buffer[8095];
nasm_assert(padding <= sizeof buffer);
if (pass_final())
nasm_nonfatal("section alignment changed during code generation");
if (coff_sects[i]->flags & IMAGE_SCN_CNT_CODE) {
/* Fill with INT 3 instructions */
memset(buffer, 0xCC, padding);
} else {
memset(buffer, 0x00, padding);
}
saa_wbytes(coff_sects[i]->data, buffer, padding);
coff_sects[i]->len += padding;
}
}
}
coff_sects[i]->pass_last_seen = pass_count();
return coff_sects[i]->index;
}
static void coff_deflabel(char *name, int32_t segment, int64_t offset,
int is_global, char *special)
{
int pos = strslen + 4;
struct coff_Symbol *sym;
if (special)
nasm_nonfatal("COFF format does not support any"
" special symbol types");
if (name[0] == '.' && name[1] == '.' && name[2] != '@') {
if (strcmp(name,WRT_IMAGEBASE))
nasm_nonfatal("unrecognized special symbol `%s'", name);
return;
}
if (strlen(name) > 8) {
size_t nlen = strlen(name)+1;
saa_wbytes(coff_strs, name, nlen);
strslen += nlen;
} else
pos = -1;
sym = saa_wstruct(coff_syms);
sym->strpos = pos;
sym->namlen = strlen(name);
if (pos == -1)
strcpy(sym->name, name);
sym->is_global = !!is_global;
sym->type = 0; /* Default to T_NULL (no type) */
if (segment == NO_SEG)
sym->section = -1; /* absolute symbol */
else {
int i;
sym->section = 0;
for (i = 0; i < coff_nsects; i++)
if (segment == coff_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, coff_nsyms);
if (segment != NO_SEG)
symval = raa_write(symval, segment, sym->section ? 0 : sym->value);
coff_nsyms++;
}
static int32_t coff_add_reloc(struct coff_Section *sect, int32_t segment,
int16_t type)
{
struct coff_Reloc *r;
r = *sect->tail = nasm_malloc(sizeof(struct coff_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 < coff_nsects; i++) {
if (segment == coff_sects[i]->index) {
r->symbol = i * 2;
r->symbase = SECT_SYMBOLS;
break;
}
}
if (r->symbase == REAL_SYMBOLS)
r->symbol = raa_read(bsym, segment);
}
r->type = type;
sect->nrelocs++;
/*
* Return the fixup for standard COFF common variables.
*/
if (r->symbase == REAL_SYMBOLS && !(win32 | win64))
return raa_read(symval, segment);
return 0;
}
static void coff_out(int32_t segto, const void *data,
enum out_type type, uint64_t size,
int32_t segment, int32_t wrt)
{
struct coff_Section *s;
uint8_t mydata[8], *p;
int i;
if (wrt != NO_SEG && !win64) {
wrt = NO_SEG; /* continue to do _something_ */
nasm_nonfatal("WRT not supported by COFF output formats");
}
s = NULL;
for (i = 0; i < coff_nsects; i++) {
if (segto == coff_sects[i]->index) {
s = coff_sects[i];
break;
}
}
if (!s) {
int tempint; /* ignored */
if (segto != coff_section_names(".text", &tempint))
nasm_panic("strange segment conditions in COFF driver");
else
s = coff_sects[coff_nsects - 1];
}
/* magically default to 'wrt ..imagebase' in .pdata and .xdata */
if (win64 && wrt == NO_SEG) {
if (!strcmp(s->name,".pdata") || !strcmp(s->name,".xdata"))
wrt = imagebase_sect;
}
if (!s->data && type != OUT_RESERVE) {
nasm_warn(WARN_OTHER, "attempt to initialize memory in"
" BSS section `%s': ignored", s->name);
s->len += realsize(type, size);
return;
}
memset(mydata, 0, sizeof(mydata));
if (dfmt && dfmt->debug_output) {
struct coff_DebugInfo dinfo;
dinfo.segto = segto;
dinfo.seg = segment;
dinfo.section = s;
if (type == OUT_ADDRESS)
dinfo.size = abs((int)size);
else
dinfo.size = realsize(type, size);
dfmt->debug_output(type, &dinfo);
}
if (type == OUT_RESERVE) {
if (s->data) {
nasm_warn(WARN_ZEROING, "uninitialised space declared in"
" non-BSS section `%s': zeroing", s->name);
coff_sect_write(s, NULL, size);
} else
s->len += size;
} else if (type == OUT_RAWDATA) {
coff_sect_write(s, data, size);
} else if (type == OUT_ADDRESS) {
int asize = abs((int)size);
if (!win64) {
if (asize != 4 && (segment != NO_SEG || wrt != NO_SEG)) {
nasm_nonfatal("COFF format does not support non-32-bit"
" relocations");
} else {
int32_t fix = 0;
if (segment != NO_SEG || wrt != NO_SEG) {
if (wrt != NO_SEG) {
nasm_nonfatal("COFF format does not support WRT types");
} else if (segment % 2) {
nasm_nonfatal("COFF format does not support"
" segment base references");
} else
fix = coff_add_reloc(s, segment, IMAGE_REL_I386_DIR32);
}
p = mydata;
WRITELONG(p, *(int64_t *)data + fix);
coff_sect_write(s, mydata, asize);
}
} else {
int32_t fix = 0;
p = mydata;
if (asize == 8) {
if (wrt == imagebase_sect) {
nasm_nonfatal("operand size mismatch: 'wrt "
WRT_IMAGEBASE "' is a 32-bit operand");
}
fix = coff_add_reloc(s, segment, IMAGE_REL_AMD64_ADDR64);
WRITEDLONG(p, *(int64_t *)data + fix);
coff_sect_write(s, mydata, asize);
} else {
fix = coff_add_reloc(s, segment,
wrt == imagebase_sect ? IMAGE_REL_AMD64_ADDR32NB:
IMAGE_REL_AMD64_ADDR32);
WRITELONG(p, *(int64_t *)data + fix);
coff_sect_write(s, mydata, asize);
}
}
} else if (type == OUT_REL2ADR) {
nasm_nonfatal("COFF format does not support 16-bit relocations");
} else if (type == OUT_REL4ADR) {
if (segment == segto && !(win64)) /* Acceptable for RIP-relative */
nasm_panic("intra-segment OUT_REL4ADR");
else if (segment == NO_SEG && win32)
nasm_nonfatal("Win32 COFF does not correctly support"
" relative references to absolute addresses");
else {
int32_t fix = 0;
if (segment != NO_SEG && segment % 2) {
nasm_nonfatal("COFF format does not support"
" segment base references");
} else
fix = coff_add_reloc(s, segment,
win64 ? IMAGE_REL_AMD64_REL32 : IMAGE_REL_I386_REL32);
p = mydata;
if (win32 | win64) {
WRITELONG(p, *(int64_t *)data + 4 - size + fix);
} else {
WRITELONG(p, *(int64_t *)data - (size + s->len) + fix);
}
coff_sect_write(s, mydata, 4L);
}
}
}
static void coff_sect_write(struct coff_Section *sect,
const uint8_t *data, uint32_t len)
{
saa_wbytes(sect->data, data, len);
sect->len += len;
}
typedef struct tagString {
struct tagString *next;
int len;
char *String;
} STRING;
#define EXPORT_SECTION_NAME ".drectve"
#define EXPORT_SECTION_FLAGS INFO_FLAGS
/*
* #define EXPORT_SECTION_NAME ".text"
* #define EXPORT_SECTION_FLAGS TEXT_FLAGS
*/
static STRING *Exports = NULL;
static struct coff_Section *directive_sec;
static void AddExport(char *name)
{
STRING *rvp = Exports, *newS;
newS = (STRING *) nasm_malloc(sizeof(STRING));
newS->len = strlen(name);
newS->next = NULL;
newS->String = (char *)nasm_malloc(newS->len + 1);
strcpy(newS->String, name);
if (rvp == NULL) {
int i;
for (i = 0; i < coff_nsects; i++) {
if (!strcmp(EXPORT_SECTION_NAME, coff_sects[i]->name))
break;
}
if (i == coff_nsects)
i = coff_make_section(EXPORT_SECTION_NAME, EXPORT_SECTION_FLAGS);
directive_sec = coff_sects[i];
Exports = newS;
} else {
while (rvp->next) {
if (!strcmp(rvp->String, name))
return;
rvp = rvp->next;
}
rvp->next = newS;
}
}
static void BuildExportTable(STRING **rvp)
{
STRING *p, *t;
if (!rvp || !*rvp)
return;
list_for_each_safe(p, t, *rvp) {
coff_sect_write(directive_sec, (uint8_t *)"-export:", 8);
coff_sect_write(directive_sec, (uint8_t *)p->String, p->len);
coff_sect_write(directive_sec, (uint8_t *)" ", 1);
nasm_free(p->String);
nasm_free(p);
}
*rvp = NULL;
}
static enum directive_result
coff_directives(enum directive directive, char *value)
{
switch (directive) {
case D_EXPORT:
{
char *q, *name;
/*
* XXX: pass_first() is really wrong here, but AddExport()
* needs to be modified to handle duplicate calls for the
* same value in order to change that. The right thing to do
* is probably to mark a label as an export in the label
* structure, in case the label doesn't actually exist.
*/
if (!pass_first())
return DIRR_OK; /* ignore in pass two */
name = q = value;
while (*q && !nasm_isspace(*q))
q++;
if (nasm_isspace(*q)) {
*q++ = '\0';
while (*q && nasm_isspace(*q))
q++;
}
if (!*name) {
nasm_nonfatal("`export' directive requires export name");
return DIRR_ERROR;
}
if (*q) {
nasm_nonfatal("unrecognized export qualifier `%s'", q);
return DIRR_ERROR;
}
AddExport(name);
return DIRR_OK;
}
case D_SAFESEH:
{
static int sxseg=-1;
int i;
if (!win32) /* Only applicable for -f win32 */
return 0;
if (sxseg == -1) {
for (i = 0; i < coff_nsects; i++)
if (!strcmp(".sxdata",coff_sects[i]->name))
break;
if (i == coff_nsects)
sxseg = coff_make_section(".sxdata", IMAGE_SCN_LNK_INFO);
else
sxseg = i;
}
/*
* pass_final() is the only time when the full set of symbols are
* guaranteed to be present as it is the final output pass.
*/
if (pass_final()) {
uint32_t n;
saa_rewind(coff_syms);
for (n = 0; n < coff_nsyms; n++) {
struct coff_Symbol *sym = saa_rstruct(coff_syms);
bool equals;
/*
* sym->strpos is biased by 4, because symbol
* table is prefixed with table length
*/
if (sym->strpos >=4) {
char *name = nasm_malloc(sym->namlen+1);
saa_fread(coff_strs, sym->strpos-4, name, sym->namlen);
name[sym->namlen] = '\0';
equals = !strcmp(value,name);
nasm_free(name);
} else {
equals = !strcmp(value,sym->name);
}
if (equals) {
/*
* this value arithmetics effectively reflects
* initsym in coff_write(): 2 for file, 1 for
* .absolute and two per each section
*/
unsigned char value[4],*p=value;
WRITELONG(p,n + 2 + 1 + coff_nsects*2);
coff_sect_write(coff_sects[sxseg],value,4);
sym->type = 0x20;
break;
}
}
if (n == coff_nsyms) {
nasm_nonfatal("`safeseh' directive requires valid symbol");
return DIRR_ERROR;
}
}
return DIRR_OK;
}
default:
return DIRR_UNKNOWN;
}
}
/* handle relocations storm, valid for win32/64 only */
static inline void coff_adjust_relocs(struct coff_Section *s)
{
if (s->nrelocs < IMAGE_SCN_MAX_RELOC)
return;
#ifdef OF_COFF
else
{
if (ofmt == &of_coff)
nasm_fatal("Too many relocations (%d) for section `%s'",
s->nrelocs, s->name);
}
#endif
s->flags |= IMAGE_SCN_LNK_NRELOC_OVFL;
s->nrelocs++;
}
static void coff_write(void)
{
int32_t pos, sympos, vsize;
int i;
/* fill in the .drectve section with -export's */
BuildExportTable(&Exports);
if (win32) {
/* add default value for @feat.00, this allows to 'link /safeseh' */
uint32_t n;
saa_rewind(coff_syms);
for (n = 0; n < coff_nsyms; n++) {
struct coff_Symbol *sym = saa_rstruct(coff_syms);
if (sym->strpos == -1 && !strcmp("@feat.00",sym->name))
break;
}
if (n == coff_nsyms)
coff_deflabel("@feat.00", NO_SEG, 1, 0, NULL);
}
/*
* Work out how big the file will get.
* Calculate the start of the `real' symbols at the same time.
* Check for massive relocations.
*/
pos = 0x14 + 0x28 * coff_nsects;
initsym = 3; /* two for the file, one absolute */
for (i = 0; i < coff_nsects; i++) {
if (coff_sects[i]->data) {
coff_adjust_relocs(coff_sects[i]);
coff_sects[i]->pos = pos;
pos += coff_sects[i]->len;
coff_sects[i]->relpos = pos;
pos += 10 * coff_sects[i]->nrelocs;
} else
coff_sects[i]->pos = coff_sects[i]->relpos = 0L;
initsym += 2; /* two for each section */
}
sympos = pos;
/*
* Output the COFF header.
*/
if (win64)
i = IMAGE_FILE_MACHINE_AMD64;
else
i = IMAGE_FILE_MACHINE_I386;
fwriteint16_t(i, ofile); /* machine type */
fwriteint16_t(coff_nsects, ofile); /* number of sections */
fwriteint32_t(time(NULL), ofile); /* time stamp */
fwriteint32_t(sympos, ofile);
fwriteint32_t(coff_nsyms + initsym, ofile);
fwriteint16_t(0, ofile); /* no optional header */
/* Flags: 32-bit, no line numbers. Win32 doesn't even bother with them. */
fwriteint16_t((win32 | win64) ? 0 : 0x104, ofile);
/*
* Output the section headers.
*/
vsize = 0L;
for (i = 0; i < coff_nsects; i++) {
coff_section_header(coff_sects[i]->name, coff_sects[i]->namepos, vsize, coff_sects[i]->len,
coff_sects[i]->pos, coff_sects[i]->relpos,
coff_sects[i]->nrelocs, coff_sects[i]->flags);
vsize += coff_sects[i]->len;
}
/*
* Output the sections and their relocations.
*/
for (i = 0; i < coff_nsects; i++)
if (coff_sects[i]->data) {
saa_fpwrite(coff_sects[i]->data, ofile);
coff_write_relocs(coff_sects[i]);
}
/*
* Output the symbol and string tables.
*/
coff_write_symbols();
fwriteint32_t(strslen + 4, ofile); /* length includes length count */
saa_fpwrite(coff_strs, ofile);
}
static void coff_section_header(char *name, int32_t namepos, int32_t vsize,
int32_t datalen, int32_t datapos,
int32_t relpos, int nrelocs, int32_t flags)
{
char padname[8];
(void)vsize;
if (namepos == -1) {
strncpy(padname, name, 8);
nasm_write(padname, 8, ofile);
} else {
/*
* If name is longer than 8 bytes, write '/' followed
* by offset into the strings table represented as
* decimal number.
*/
namepos = namepos % 100000000;
padname[0] = '/';
padname[1] = '0' + (namepos / 1000000);
namepos = namepos % 1000000;
padname[2] = '0' + (namepos / 100000);
namepos = namepos % 100000;
padname[3] = '0' + (namepos / 10000);
namepos = namepos % 10000;
padname[4] = '0' + (namepos / 1000);
namepos = namepos % 1000;
padname[5] = '0' + (namepos / 100);
namepos = namepos % 100;
padname[6] = '0' + (namepos / 10);
namepos = namepos % 10;
padname[7] = '0' + (namepos);
nasm_write(padname, 8, ofile);
}
fwriteint32_t(0, ofile); /* Virtual size field - set to 0 or vsize */
fwriteint32_t(0L, ofile); /* RVA/offset - we ignore */
fwriteint32_t(datalen, ofile);
fwriteint32_t(datapos, ofile);
fwriteint32_t(relpos, ofile);
fwriteint32_t(0L, ofile); /* no line numbers - we don't do 'em */
/*
* a special case -- if there are too many relocs
* we have to put IMAGE_SCN_MAX_RELOC here and write
* the real relocs number into VirtualAddress of first
* relocation
*/
if (flags & IMAGE_SCN_LNK_NRELOC_OVFL)
fwriteint16_t(IMAGE_SCN_MAX_RELOC, ofile);
else
fwriteint16_t(nrelocs, ofile);
fwriteint16_t(0, ofile); /* again, no line numbers */
fwriteint32_t(flags, ofile);
}
static void coff_write_relocs(struct coff_Section *s)
{
struct coff_Reloc *r;
/* a real number of relocations if needed */
if (s->flags & IMAGE_SCN_LNK_NRELOC_OVFL) {
fwriteint32_t(s->nrelocs, ofile);
fwriteint32_t(0, ofile);
fwriteint16_t(0, ofile);
}
for (r = s->head; r; r = r->next) {
fwriteint32_t(r->address, ofile);
fwriteint32_t(r->symbol + (r->symbase == REAL_SYMBOLS ? initsym :
r->symbase == ABS_SYMBOL ? initsym - 1 :
r->symbase == SECT_SYMBOLS ? 2 : 0),
ofile);
fwriteint16_t(r->type, ofile);
}
}
static void coff_symbol(char *name, int32_t strpos, int32_t value,
int section, int type, int storageclass, int aux)
{
char padname[8];
if (name) {
strncpy(padname, name, 8);
nasm_write(padname, 8, ofile);
} else {
fwriteint32_t(0, ofile);
fwriteint32_t(strpos, ofile);
}
fwriteint32_t(value, ofile);
fwriteint16_t(section, ofile);
fwriteint16_t(type, ofile);
fputc(storageclass, ofile);
fputc(aux, ofile);
}
static void coff_write_symbols(void)
{
char filename[18];
uint32_t i;
/*
* The `.file' record, and the file name auxiliary record.
*/
coff_symbol(".file", 0L, 0L, -2, 0, 0x67, 1);
strncpy(filename, inname, 18);
nasm_write(filename, 18, ofile);
/*
* The section records, with their auxiliaries.
*/
memset(filename, 0, 18); /* useful zeroed buffer */
for (i = 0; i < (uint32_t) coff_nsects; i++) {
coff_symbol(coff_sects[i]->name, 0L, 0L, i + 1, 0, 3, 1);
fwriteint32_t(coff_sects[i]->len, ofile);
fwriteint16_t(coff_sects[i]->nrelocs,ofile);
nasm_write(filename, 12, ofile);
}
/*
* The absolute symbol, for relative-to-absolute relocations.
*/
coff_symbol(".absolut", 0L, 0L, -1, 0, 3, 0);
/*
* The real symbols.
*/
saa_rewind(coff_syms);
for (i = 0; i < coff_nsyms; i++) {
struct coff_Symbol *sym = saa_rstruct(coff_syms);
coff_symbol(sym->strpos == -1 ? sym->name : NULL,
sym->strpos, sym->value, sym->section,
sym->type, sym->is_global ? 2 : 3, 0);
}
}
static void coff_sectalign(int32_t seg, unsigned int value)
{
struct coff_Section *s = NULL;
uint32_t align;
int i;
for (i = 0; i < coff_nsects; i++) {
if (coff_sects[i]->index == seg) {
s = coff_sects[i];
break;
}
}
if (!s || !is_power2(value))
return;
/* DOS has limitation on 64 bytes */
if (!(win32 | win64) && value > 64)
return;
align = (s->flags & IMAGE_SCN_ALIGN_MASK);
value = coff_sectalign_flags(value);
if (value > align)
s->flags = (s->flags & ~IMAGE_SCN_ALIGN_MASK) | value;
}
extern macros_t coff_stdmac[];
#endif /* defined(OF_COFF) || defined(OF_WIN32) */
#ifdef OF_COFF
static const struct pragma_facility coff_pragma_list[] = {
{ "coff", NULL },
{ NULL, NULL }
};
const struct ofmt of_coff = {
"COFF (i386) (DJGPP, some Unix variants)",
"coff",
".o",
0,
32,
null_debug_arr,
&null_debug_form,
coff_stdmac,
coff_std_init,
null_reset,
nasm_do_legacy_output,
coff_out,
coff_deflabel,
coff_section_names,
NULL,
coff_sectalign,
null_segbase,
coff_directives,
coff_cleanup,
coff_pragma_list
};
#endif
#ifdef OF_WIN32
static const struct pragma_facility coff_win_pragma_list[] = {
{ "win", NULL },
{ "coff", NULL },
{ NULL, NULL }
};
extern const struct dfmt df_cv8;
static const struct dfmt * const win32_debug_arr[2] = { &df_cv8, NULL };
const struct ofmt of_win32 = {
"Microsoft extended COFF for Win32 (i386)",
"win32",
".obj",
0,
32,
win32_debug_arr,
&df_cv8,
coff_stdmac,
coff_win32_init,
null_reset,
nasm_do_legacy_output,
coff_out,
coff_deflabel,
coff_section_names,
NULL,
coff_sectalign,
null_segbase,
coff_directives,
coff_cleanup,
coff_win_pragma_list
};
#endif
#ifdef OF_WIN64
static const struct dfmt * const win64_debug_arr[2] = { &df_cv8, NULL };
const struct ofmt of_win64 = {
"Microsoft extended COFF for Win64 (x86-64)",
"win64",
".obj",
0,
64,
win64_debug_arr,
&df_cv8,
coff_stdmac,
coff_win64_init,
null_reset,
nasm_do_legacy_output,
coff_out,
coff_deflabel,
coff_section_names,
NULL,
coff_sectalign,
null_segbase,
coff_directives,
coff_cleanup,
coff_win_pragma_list
};
#endif
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