/* BFD back-end for WebAssembly modules.
- Copyright (C) 2017-2018 Free Software Foundation, Inc.
+ Copyright (C) 2017-2021 Free Software Foundation, Inc.
Based on srec.c, mmo.c, and binary.c
https://github.com/WebAssembly/design/blob/master/BinaryEncoding.md. */
#include "sysdep.h"
-#include "alloca-conf.h"
#include "bfd.h"
-#include <limits.h>
#include "libiberty.h"
#include "libbfd.h"
#include "wasm-module.h"
+#include <limits.h>
+#ifndef CHAR_BIT
+#define CHAR_BIT 8
+#endif
+
typedef struct
{
asymbol * symbols;
incomplete numbers). SIGN means interpret the number as SLEB128. */
static bfd_vma
-wasm_read_leb128 (bfd * abfd,
- bfd_boolean * error_return,
- unsigned int * length_return,
- bfd_boolean sign)
+wasm_read_leb128 (bfd *abfd,
+ bool *error_return,
+ unsigned int *length_return,
+ bool sign)
{
bfd_vma result = 0;
unsigned int num_read = 0;
unsigned int shift = 0;
unsigned char byte = 0;
- bfd_boolean success = FALSE;
+ unsigned char lost, mask;
+ int status = 1;
while (bfd_bread (&byte, 1, abfd) == 1)
{
num_read++;
- result |= ((bfd_vma) (byte & 0x7f)) << shift;
+ if (shift < CHAR_BIT * sizeof (result))
+ {
+ result |= ((bfd_vma) (byte & 0x7f)) << shift;
+ /* These bits overflowed. */
+ lost = byte ^ (result >> shift);
+ /* And this is the mask of possible overflow bits. */
+ mask = 0x7f ^ ((bfd_vma) 0x7f << shift >> shift);
+ shift += 7;
+ }
+ else
+ {
+ lost = byte;
+ mask = 0x7f;
+ }
+ if ((lost & mask) != (sign && (bfd_signed_vma) result < 0 ? mask : 0))
+ status |= 2;
- shift += 7;
if ((byte & 0x80) == 0)
{
- success = TRUE;
+ status &= ~1;
+ if (sign && shift < CHAR_BIT * sizeof (result) && (byte & 0x40))
+ result |= -((bfd_vma) 1 << shift);
break;
}
}
if (length_return != NULL)
*length_return = num_read;
if (error_return != NULL)
- *error_return = ! success;
-
- if (sign && (shift < 8 * sizeof (result)) && (byte & 0x40))
- result |= -((bfd_vma) 1 << shift);
+ *error_return = status != 0;
return result;
}
/* Encode an integer V as LEB128 and write it to ABFD, return TRUE on
success. */
-static bfd_boolean
+static bool
wasm_write_uleb128 (bfd *abfd, bfd_vma v)
{
do
c |= 0x80;
if (bfd_bwrite (&c, 1, abfd) != 1)
- return FALSE;
+ return false;
}
while (v);
- return TRUE;
+ return true;
}
/* Read the LEB128 integer at P, saving it to X; at end of buffer,
#define READ_LEB128(x, p, end) \
do \
{ \
- unsigned int length_read; \
- (x) = _bfd_safe_read_leb128 (abfd, (p), &length_read, \
- FALSE, (end)); \
- (p) += length_read; \
- if (length_read == 0) \
+ if ((p) >= (end)) \
goto error_return; \
+ (x) = _bfd_safe_read_leb128 (abfd, &(p), false, (end)); \
} \
while (0)
/* Verify the magic number at the beginning of a WebAssembly module
ABFD, setting ERRORPTR if there's a mismatch. */
-static bfd_boolean
-wasm_read_magic (bfd *abfd, bfd_boolean *errorptr)
+static bool
+wasm_read_magic (bfd *abfd, bool *errorptr)
{
bfd_byte magic_const[SIZEOF_WASM_MAGIC] = WASM_MAGIC;
bfd_byte magic[SIZEOF_WASM_MAGIC];
if (bfd_bread (magic, sizeof (magic), abfd) == sizeof (magic)
&& memcmp (magic, magic_const, sizeof (magic)) == 0)
- return TRUE;
+ return true;
- *errorptr = TRUE;
- return FALSE;
+ *errorptr = true;
+ return false;
}
/* Read the version number from ABFD, returning TRUE if it's a supported
version. Set ERRORPTR otherwise. */
-static bfd_boolean
-wasm_read_version (bfd *abfd, bfd_boolean *errorptr)
+static bool
+wasm_read_version (bfd *abfd, bool *errorptr)
{
bfd_byte vers_const[SIZEOF_WASM_VERSION] = WASM_VERSION;
bfd_byte vers[SIZEOF_WASM_VERSION];
/* Don't attempt to parse newer versions, which are likely to
require code changes. */
&& memcmp (vers, vers_const, sizeof (vers)) == 0)
- return TRUE;
+ return true;
- *errorptr = TRUE;
- return FALSE;
+ *errorptr = true;
+ return false;
}
/* Read the WebAssembly header (magic number plus version number) from
ABFD, setting ERRORPTR to TRUE if there is a mismatch. */
-static bfd_boolean
-wasm_read_header (bfd *abfd, bfd_boolean *errorptr)
+static bool
+wasm_read_header (bfd *abfd, bool *errorptr)
{
if (! wasm_read_magic (abfd, errorptr))
- return FALSE;
+ return false;
if (! wasm_read_version (abfd, errorptr))
- return FALSE;
+ return false;
- return TRUE;
+ return true;
}
/* Scan the "function" subsection of the "name" section ASECT in the
wasm module ABFD. Create symbols. Return TRUE on success. */
-static bfd_boolean
+static bool
wasm_scan_name_function_section (bfd *abfd, sec_ptr asect)
{
bfd_byte *p;
tdata_type *tdata = abfd->tdata.any;
asymbol *symbols = NULL;
sec_ptr space_function_index;
-
- if (! asect)
- return FALSE;
-
- if (strcmp (asect->name, WASM_NAME_SECTION) != 0)
- return FALSE;
+ size_t amt;
p = asect->contents;
end = asect->contents + asect->size;
- if (! p)
- return FALSE;
+ if (!p)
+ return false;
while (p < end)
{
it has to be a single byte in the 0 - 127 range. If it isn't,
the spec must have changed underneath us, so give up. */
if (subsection_code & 0x80)
- return FALSE;
+ return false;
READ_LEB128 (payload_size, p, end);
- if (p > p + payload_size)
- return FALSE;
+ if (payload_size > (size_t) (end - p))
+ return false;
p += payload_size;
}
if (p >= end)
- return FALSE;
+ return false;
READ_LEB128 (payload_size, p, end);
- if (p > p + payload_size)
- return FALSE;
-
- if (p + payload_size > end)
- return FALSE;
+ if (payload_size > (size_t) (end - p))
+ return false;
end = p + payload_size;
READ_LEB128 (symcount, p, end);
/* Sanity check: each symbol has at least two bytes. */
- if (symcount > payload_size/2)
- return FALSE;
+ if (symcount > payload_size / 2)
+ return false;
tdata->symcount = symcount;
- space_function_index = bfd_make_section_with_flags
- (abfd, WASM_SECTION_FUNCTION_INDEX, SEC_READONLY | SEC_CODE);
+ space_function_index
+ = bfd_make_section_with_flags (abfd, WASM_SECTION_FUNCTION_INDEX,
+ SEC_READONLY | SEC_CODE);
- if (! space_function_index)
- space_function_index = bfd_get_section_by_name (abfd, WASM_SECTION_FUNCTION_INDEX);
+ if (!space_function_index)
+ space_function_index
+ = bfd_get_section_by_name (abfd, WASM_SECTION_FUNCTION_INDEX);
- if (! space_function_index)
- return FALSE;
+ if (!space_function_index)
+ return false;
- symbols = bfd_zalloc (abfd, tdata->symcount * sizeof (asymbol));
- if (! symbols)
- return FALSE;
+ if (_bfd_mul_overflow (tdata->symcount, sizeof (asymbol), &amt))
+ {
+ bfd_set_error (bfd_error_file_too_big);
+ return false;
+ }
+ symbols = bfd_alloc (abfd, amt);
+ if (!symbols)
+ return false;
for (symcount = 0; p < end && symcount < tdata->symcount; symcount++)
{
READ_LEB128 (idx, p, end);
READ_LEB128 (len, p, end);
- if (p + len < p || p + len > end)
+ if (len > (size_t) (end - p))
goto error_return;
- name = bfd_zalloc (abfd, len + 1);
- if (! name)
+ name = bfd_alloc (abfd, len + 1);
+ if (!name)
goto error_return;
memcpy (name, p, len);
+ name[len] = 0;
p += len;
sym = &symbols[symcount];
tdata->symbols = symbols;
abfd->symcount = symcount;
- return TRUE;
+ return true;
error_return:
- while (symcount)
- bfd_release (abfd, (void *)symbols[--symcount].name);
bfd_release (abfd, symbols);
- return FALSE;
+ return false;
}
/* Read a byte from ABFD and return it, or EOF for EOF or error.
Set ERRORPTR on non-EOF error. */
static int
-wasm_read_byte (bfd *abfd, bfd_boolean *errorptr)
+wasm_read_byte (bfd *abfd, bool *errorptr)
{
bfd_byte byte;
if (bfd_bread (&byte, (bfd_size_type) 1, abfd) != 1)
{
if (bfd_get_error () != bfd_error_file_truncated)
- *errorptr = TRUE;
+ *errorptr = true;
return EOF;
}
/* Scan the wasm module ABFD, creating sections and symbols.
Return TRUE on success. */
-static bfd_boolean
+static bool
wasm_scan (bfd *abfd)
{
- bfd_boolean error = FALSE;
+ bool error = false;
/* Fake VMAs for now. Choose 0x80000000 as base to avoid clashes
with actual data addresses. */
bfd_vma vma = 0x80000000;
int section_code;
unsigned int bytes_read;
- char *name = NULL;
asection *bfdsec;
if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
goto error_return;
- if (! wasm_read_header (abfd, &error))
+ if (!wasm_read_header (abfd, &error))
goto error_return;
while ((section_code = wasm_read_byte (abfd, &error)) != EOF)
{
const char *sname = wasm_section_code_to_name (section_code);
- if (! sname)
+ if (!sname)
goto error_return;
- name = strdup (sname);
- bfdsec = bfd_make_section_anyway_with_flags (abfd, name, SEC_HAS_CONTENTS);
+ bfdsec = bfd_make_section_anyway_with_flags (abfd, sname,
+ SEC_HAS_CONTENTS);
if (bfdsec == NULL)
goto error_return;
- name = NULL;
- bfdsec->vma = vma;
- bfdsec->lma = vma;
- bfdsec->size = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE);
+ bfdsec->size = wasm_read_leb128 (abfd, &error, &bytes_read, false);
if (error)
goto error_return;
- bfdsec->filepos = bfd_tell (abfd);
- bfdsec->alignment_power = 0;
}
else
{
bfd_vma payload_len;
- file_ptr section_start;
bfd_vma namelen;
+ char *name;
char *prefix = WASM_SECTION_PREFIX;
- char *p;
- int ret;
+ size_t prefixlen = strlen (prefix);
+ ufile_ptr filesize;
- payload_len = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE);
+ payload_len = wasm_read_leb128 (abfd, &error, &bytes_read, false);
if (error)
goto error_return;
- section_start = bfd_tell (abfd);
- namelen = wasm_read_leb128 (abfd, &error, &bytes_read, FALSE);
- if (error || namelen > payload_len)
- goto error_return;
- name = bfd_zmalloc (namelen + strlen (prefix) + 1);
- if (! name)
+ namelen = wasm_read_leb128 (abfd, &error, &bytes_read, false);
+ if (error || bytes_read > payload_len
+ || namelen > payload_len - bytes_read)
goto error_return;
- p = name;
- ret = sprintf (p, "%s", prefix);
- if (ret < 0 || (bfd_vma) ret != strlen (prefix))
+ payload_len -= namelen + bytes_read;
+ filesize = bfd_get_file_size (abfd);
+ if (filesize != 0 && namelen > filesize)
+ {
+ bfd_set_error (bfd_error_file_truncated);
+ return false;
+ }
+ name = bfd_alloc (abfd, namelen + prefixlen + 1);
+ if (!name)
goto error_return;
- p += ret;
- if (bfd_bread (p, namelen, abfd) != namelen)
+ memcpy (name, prefix, prefixlen);
+ if (bfd_bread (name + prefixlen, namelen, abfd) != namelen)
goto error_return;
+ name[prefixlen + namelen] = 0;
- bfdsec = bfd_make_section_anyway_with_flags (abfd, name, SEC_HAS_CONTENTS);
+ bfdsec = bfd_make_section_anyway_with_flags (abfd, name,
+ SEC_HAS_CONTENTS);
if (bfdsec == NULL)
goto error_return;
- name = NULL;
- bfdsec->vma = vma;
- bfdsec->lma = vma;
- bfdsec->filepos = bfd_tell (abfd);
- bfdsec->size = section_start + payload_len - bfdsec->filepos;
- bfdsec->alignment_power = 0;
+ bfdsec->size = payload_len;
}
+ bfdsec->vma = vma;
+ bfdsec->lma = vma;
+ bfdsec->alignment_power = 0;
+ bfdsec->filepos = bfd_tell (abfd);
if (bfdsec->size != 0)
{
- bfdsec->contents = bfd_zalloc (abfd, bfdsec->size);
- if (! bfdsec->contents)
- goto error_return;
-
- if (bfd_bread (bfdsec->contents, bfdsec->size, abfd) != bfdsec->size)
+ bfdsec->contents = _bfd_alloc_and_read (abfd, bfdsec->size,
+ bfdsec->size);
+ if (!bfdsec->contents)
goto error_return;
}
if (error)
goto error_return;
- return TRUE;
+ return true;
error_return:
- if (name)
- free (name);
-
- for (bfdsec = abfd->sections; bfdsec; bfdsec = bfdsec->next)
- free ((void *) bfdsec->name);
-
- return FALSE;
+ return false;
}
/* Put a numbered section ASECT of ABFD into the table of numbered
struct compute_section_arg
{
bfd_vma pos;
- bfd_boolean failed;
+ bool failed;
};
/* Compute the file position of ABFD's section ASECT. FSARG is a
if (idx != 0)
return;
- if (CONST_STRNEQ (asect->name, WASM_SECTION_PREFIX))
+ if (startswith (asect->name, WASM_SECTION_PREFIX))
{
const char *name = asect->name + strlen (WASM_SECTION_PREFIX);
bfd_size_type payload_len = asect->size;
return;
error_return:
- fs->failed = TRUE;
+ fs->failed = true;
}
/* Compute the file positions for the sections of ABFD. Currently,
their ids, but custom sections can appear in any position and any
order, and more than once. FIXME: support that. */
-static bfd_boolean
+static bool
wasm_compute_section_file_positions (bfd *abfd)
{
bfd_byte magic[SIZEOF_WASM_MAGIC] = WASM_MAGIC;
if (bfd_bwrite (magic, sizeof (magic), abfd) != (sizeof magic)
|| bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers))
- return FALSE;
+ return false;
for (i = 0; i < WASM_NUMBERED_SECTIONS; i++)
numbered_sections[i] = NULL;
continue;
size = sec->size;
if (bfd_seek (abfd, fs.pos, SEEK_SET) != 0)
- return FALSE;
+ return false;
if (! wasm_write_uleb128 (abfd, i)
|| ! wasm_write_uleb128 (abfd, size))
- return FALSE;
+ return false;
fs.pos = sec->filepos = bfd_tell (abfd);
fs.pos += size;
}
- fs.failed = FALSE;
+ fs.failed = false;
bfd_map_over_sections (abfd, wasm_compute_custom_section_file_position, &fs);
if (fs.failed)
- return FALSE;
+ return false;
- abfd->output_has_begun = TRUE;
+ abfd->output_has_begun = true;
- return TRUE;
+ return true;
}
-static bfd_boolean
+static bool
wasm_set_section_contents (bfd *abfd,
sec_ptr section,
const void *location,
bfd_size_type count)
{
if (count == 0)
- return TRUE;
+ return true;
if (! abfd->output_has_begun
&& ! wasm_compute_section_file_positions (abfd))
- return FALSE;
+ return false;
if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0
|| bfd_bwrite (location, count, abfd) != count)
- return FALSE;
+ return false;
- return TRUE;
+ return true;
}
-static bfd_boolean
+static bool
wasm_write_object_contents (bfd* abfd)
{
bfd_byte magic[] = WASM_MAGIC;
bfd_byte vers[] = WASM_VERSION;
if (bfd_seek (abfd, 0, SEEK_SET) != 0)
- return FALSE;
+ return false;
if (bfd_bwrite (magic, sizeof (magic), abfd) != sizeof (magic)
|| bfd_bwrite (vers, sizeof (vers), abfd) != sizeof (vers))
- return FALSE;
+ return false;
- return TRUE;
+ return true;
}
-static bfd_boolean
+static bool
wasm_mkobject (bfd *abfd)
{
tdata_type *tdata = (tdata_type *) bfd_alloc (abfd, sizeof (tdata_type));
if (! tdata)
- return FALSE;
+ return false;
tdata->symbols = NULL;
tdata->symcount = 0;
abfd->tdata.any = tdata;
- return TRUE;
+ return true;
}
static long
static asymbol *
wasm_make_empty_symbol (bfd *abfd)
{
- bfd_size_type amt = sizeof (asymbol);
+ size_t amt = sizeof (asymbol);
asymbol *new_symbol = (asymbol *) bfd_zalloc (abfd, amt);
if (! new_symbol)
/* Check whether ABFD is a WebAssembly module; if so, scan it. */
-static const bfd_target *
+static bfd_cleanup
wasm_object_p (bfd *abfd)
{
- bfd_boolean error;
+ bool error;
+ asection *s;
if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
return NULL;
- if (! wasm_read_header (abfd, &error))
+ if (!wasm_read_header (abfd, &error))
{
bfd_set_error (bfd_error_wrong_format);
return NULL;
}
- if (! wasm_mkobject (abfd) || ! wasm_scan (abfd))
+ if (!wasm_mkobject (abfd))
return NULL;
- if (! bfd_default_set_arch_mach (abfd, bfd_arch_wasm32, 0))
- return NULL;
+ if (!wasm_scan (abfd)
+ || !bfd_default_set_arch_mach (abfd, bfd_arch_wasm32, 0))
+ {
+ bfd_release (abfd, abfd->tdata.any);
+ abfd->tdata.any = NULL;
+ return NULL;
+ }
- if (wasm_scan_name_function_section (abfd, bfd_get_section_by_name (abfd, WASM_NAME_SECTION)))
+ s = bfd_get_section_by_name (abfd, WASM_NAME_SECTION);
+ if (s != NULL && wasm_scan_name_function_section (abfd, s))
abfd->flags |= HAS_SYMS;
- return abfd->xvec;
+ return _bfd_no_cleanup;
}
/* BFD_JUMP_TABLE_WRITE */
' ', /* AR_pad_char. */
255, /* AR_max_namelen. */
0, /* Match priority. */
+ TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols. */
/* Routines to byte-swap various sized integers from the data sections. */
bfd_getl64, bfd_getl_signed_64, bfd_putl64,
bfd_getl32, bfd_getl_signed_32, bfd_putl32,
projects / deliverable / binutils-gdb.git / blobdiff