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[refactoring] Extract read leb to a separate file, share the code between loader and mini loader (#3701)

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There's probably a number of other places where the bh_leb_read could be used (e.g. aot loader)
but I'm making the change as small as possible. Further refactoring can be done later.
This commit is contained in:
Marcin Kolny
2024-08-14 01:46:24 +01:00
committed by GitHub
parent a83adccd20
commit 37d7439ef9
9 changed files with 223 additions and 159 deletions
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81
core/iwasm/interpreter/wasm_loader.c
View File

@ -56,10 +56,7 @@ has_module_memory64(WASMModule *module)
static void
set_error_buf(char *error_buf, uint32 error_buf_size, const char *string)
{
if (error_buf != NULL) {
snprintf(error_buf, error_buf_size, "WASM module load failed: %s",
string);
}
wasm_loader_set_error_buf(error_buf, error_buf_size, string, false);
}
#if WASM_ENABLE_MEMORY64 != 0
@ -131,82 +128,6 @@ check_buf1(const uint8 *buf, const uint8 *buf_end, uint32 length,
#define skip_leb_int32(p, p_end) skip_leb(p)
#define skip_leb_mem_offset(p, p_end) skip_leb(p)
static bool
read_leb(uint8 **p_buf, const uint8 *buf_end, uint32 maxbits, bool sign,
uint64 *p_result, char *error_buf, uint32 error_buf_size)
{
const uint8 *buf = *p_buf;
uint64 result = 0;
uint32 shift = 0;
uint32 offset = 0, bcnt = 0;
uint64 byte;
while (true) {
/* uN or SN must not exceed ceil(N/7) bytes */
if (bcnt + 1 > (maxbits + 6) / 7) {
set_error_buf(error_buf, error_buf_size,
"integer representation too long");
return false;
}
CHECK_BUF(buf, buf_end, offset + 1);
byte = buf[offset];
offset += 1;
result |= ((byte & 0x7f) << shift);
shift += 7;
bcnt += 1;
if ((byte & 0x80) == 0) {
break;
}
}
if (!sign && maxbits == 32 && shift >= maxbits) {
/* The top bits set represent values > 32 bits */
if (((uint8)byte) & 0xf0)
goto fail_integer_too_large;
}
else if (sign && maxbits == 32) {
if (shift < maxbits) {
/* Sign extend, second-highest bit is the sign bit */
if ((uint8)byte & 0x40)
result |= (~((uint64)0)) << shift;
}
else {
/* The top bits should be a sign-extension of the sign bit */
bool sign_bit_set = ((uint8)byte) & 0x8;
int top_bits = ((uint8)byte) & 0xf0;
if ((sign_bit_set && top_bits != 0x70)
|| (!sign_bit_set && top_bits != 0))
goto fail_integer_too_large;
}
}
else if (sign && maxbits == 64) {
if (shift < maxbits) {
/* Sign extend, second-highest bit is the sign bit */
if ((uint8)byte & 0x40)
result |= (~((uint64)0)) << shift;
}
else {
/* The top bits should be a sign-extension of the sign bit */
bool sign_bit_set = ((uint8)byte) & 0x1;
int top_bits = ((uint8)byte) & 0xfe;
if ((sign_bit_set && top_bits != 0x7e)
|| (!sign_bit_set && top_bits != 0))
goto fail_integer_too_large;
}
}
*p_buf += offset;
*p_result = result;
return true;
fail_integer_too_large:
set_error_buf(error_buf, error_buf_size, "integer too large");
fail:
return false;
}
#define read_uint8(p) TEMPLATE_READ_VALUE(uint8, p)
#define read_uint32(p) TEMPLATE_READ_VALUE(uint32, p)

69
core/iwasm/interpreter/wasm_mini_loader.c
View File

@ -44,9 +44,7 @@ has_module_memory64(WASMModule *module)
static void
set_error_buf(char *error_buf, uint32 error_buf_size, const char *string)
{
if (error_buf != NULL)
snprintf(error_buf, error_buf_size, "WASM module load failed: %s",
string);
wasm_loader_set_error_buf(error_buf, error_buf_size, string, false);
}
#define CHECK_BUF(buf, buf_end, length) \
@ -95,71 +93,6 @@ is_byte_a_type(uint8 type)
|| (type == VALUE_TYPE_VOID);
}
static void
read_leb(uint8 **p_buf, const uint8 *buf_end, uint32 maxbits, bool sign,
uint64 *p_result, char *error_buf, uint32 error_buf_size)
{
const uint8 *buf = *p_buf;
uint64 result = 0;
uint32 shift = 0;
uint32 offset = 0, bcnt = 0;
uint64 byte;
while (true) {
bh_assert(bcnt + 1 <= (maxbits + 6) / 7);
CHECK_BUF(buf, buf_end, offset + 1);
byte = buf[offset];
offset += 1;
result |= ((byte & 0x7f) << shift);
shift += 7;
bcnt += 1;
if ((byte & 0x80) == 0) {
break;
}
}
if (!sign && maxbits == 32 && shift >= maxbits) {
/* The top bits set represent values > 32 bits */
bh_assert(!(((uint8)byte) & 0xf0));
}
else if (sign && maxbits == 32) {
if (shift < maxbits) {
/* Sign extend, second-highest bit is the sign bit */
if ((uint8)byte & 0x40)
result |= (~((uint64)0)) << shift;
}
else {
/* The top bits should be a sign-extension of the sign bit */
bool sign_bit_set = ((uint8)byte) & 0x8;
int top_bits = ((uint8)byte) & 0xf0;
bh_assert(!((sign_bit_set && top_bits != 0x70)
|| (!sign_bit_set && top_bits != 0)));
(void)top_bits;
(void)sign_bit_set;
}
}
else if (sign && maxbits == 64) {
if (shift < maxbits) {
/* Sign extend, second-highest bit is the sign bit */
if ((uint8)byte & 0x40)
result |= (~((uint64)0)) << shift;
}
else {
/* The top bits should be a sign-extension of the sign bit */
bool sign_bit_set = ((uint8)byte) & 0x1;
int top_bits = ((uint8)byte) & 0xfe;
bh_assert(!((sign_bit_set && top_bits != 0x7e)
|| (!sign_bit_set && top_bits != 0)));
(void)top_bits;
(void)sign_bit_set;
}
}
*p_buf += offset;
*p_result = result;
}
#define read_uint8(p) TEMPLATE_READ_VALUE(uint8, p)
#define read_uint32(p) TEMPLATE_READ_VALUE(uint32, p)
#define read_bool(p) TEMPLATE_READ_VALUE(bool, p)