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nasm/output/outcoff.c
H. Peter Anvin (Intel) cd87431424 BR 3392692: outcoff: allow user to reduce the default alignment 
NASM would incorrectly only allow for the alignment to be increased,
even when overridden by the user. Allow the user to specify any
alignment value and have it override the partition type default.

The user can increade their own alignment value specification later,
of course, and the sectalign directive will present a floor for either
kind of specification.

Reported-by: Dale Curtis <dalecurtis@chromium.org>
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
2020-07-06 21:46:43 -07:00

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/* ----------------------------------------------------------------------- *
*
* Copyright 1996-2020 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 COFF_MAX_ALIGNMENT 8192
#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 uint32_t coff_sectalign_flags(unsigned int align)
{
return (ilog2_32(align) + 1) << 20;
}
static inline unsigned int coff_alignment(uint32_t flags)
{
return 1U << (((flags & IMAGE_SCN_ALIGN_MASK) >> 20) - 1);
}
static int32_t coff_section_names(char *name, int *bits)
{
char *p;
uint32_t flags, align_flags;
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 = align_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 (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 > 8192) {
nasm_nonfatal("maximum alignment in COFF is %d bytes",
COFF_MAX_ALIGNMENT);
} else {
align_flags = 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;
} else if (flags) {
/* Check if any flags are respecified */
/* 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) {
uint32_t sect_align_flags = coff_sects[i]->align_flags;
/* Compute the actual alignment */
unsigned int align = coff_alignment(align_flags);
/* Update section header as needed */
if (align_flags > sect_align_flags) {
coff_sects[i]->align_flags = align_flags;
}
/* Check if not already aligned */
/* XXX: other formats don't do this... */
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++;
}
/*
* Make sure we satisfy all section alignment requirements and put the
* resulting alignment flags into the flags value in the header. If
* no user-specified alignment is given, use the default for the
* section type; then either way round up to alignment specified by
* sectalign directives.
*/
static inline void coff_adjust_alignment(struct coff_Section *s)
{
uint32_t align_flags = s->align_flags;
if (!align_flags) {
/* No user-specified alignment, use default for partition type */
align_flags = s->flags & IMAGE_SCN_ALIGN_MASK;
}
if (align_flags < s->sectalign_flags)
align_flags = s->sectalign_flags;
s->flags = (s->flags & ~IMAGE_SCN_ALIGN_MASK) | align_flags;
}
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++) {
coff_adjust_alignment(coff_sects[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 flags;
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;
if (value > COFF_MAX_ALIGNMENT)
value = COFF_MAX_ALIGNMENT; /* Do our best... */
flags = coff_sectalign_flags(value);
if (flags > s->sectalign_flags)
s->sectalign_flags = flags;
}
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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