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bpo-36389: Fix _PyBytesWriter in release mode (GH-16624)
Fix _PyBytesWriter API when Python is built in release mode with assertions.
This commit is contained in:
Victor Stinner
GitHub
parent
6876257eaa
commit
60ec6efd96
3 changed files with 48 additions and 47 deletions
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@ -2031,20 +2031,6 @@ _Py_GetAllocatedBlocks(void)
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* it wraps a real allocator, adding extra debugging info to the memory blocks.
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*/
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/* Special bytes broadcast into debug memory blocks at appropriate times.
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* Strings of these are unlikely to be valid addresses, floats, ints or
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* 7-bit ASCII. If modified, _PyMem_IsPtrFreed() should be updated as well.
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*
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* Byte patterns 0xCB, 0xBB and 0xFB have been replaced with 0xCD, 0xDD and
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* 0xFD to use the same values than Windows CRT debug malloc() and free().
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*/
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#undef CLEANBYTE
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#undef DEADBYTE
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#undef FORBIDDENBYTE
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#define CLEANBYTE 0xCD /* clean (newly allocated) memory */
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#define DEADBYTE 0xDD /* dead (newly freed) memory */
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#define FORBIDDENBYTE 0xFD /* untouchable bytes at each end of a block */
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/* Uncomment this define to add the "serialno" field */
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/* #define PYMEM_DEBUG_SERIALNO */
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@ -2106,14 +2092,14 @@ p[0: S]
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p[S]
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API ID. See PEP 445. This is a character, but seems undocumented.
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p[S+1: 2*S]
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Copies of FORBIDDENBYTE. Used to catch under- writes and reads.
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Copies of PYMEM_FORBIDDENBYTE. Used to catch under- writes and reads.
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p[2*S: 2*S+n]
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The requested memory, filled with copies of CLEANBYTE.
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The requested memory, filled with copies of PYMEM_CLEANBYTE.
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Used to catch reference to uninitialized memory.
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&p[2*S] is returned. Note that this is 8-byte aligned if pymalloc
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handled the request itself.
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p[2*S+n: 2*S+n+S]
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Copies of FORBIDDENBYTE. Used to catch over- writes and reads.
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Copies of PYMEM_FORBIDDENBYTE. Used to catch over- writes and reads.
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p[2*S+n+S: 2*S+n+2*S]
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A serial number, incremented by 1 on each call to _PyMem_DebugMalloc
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and _PyMem_DebugRealloc.
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@ -2170,15 +2156,15 @@ _PyMem_DebugRawAlloc(int use_calloc, void *ctx, size_t nbytes)
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/* at p, write size (SST bytes), id (1 byte), pad (SST-1 bytes) */
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write_size_t(p, nbytes);
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p[SST] = (uint8_t)api->api_id;
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memset(p + SST + 1, FORBIDDENBYTE, SST-1);
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memset(p + SST + 1, PYMEM_FORBIDDENBYTE, SST-1);
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if (nbytes > 0 && !use_calloc) {
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memset(data, CLEANBYTE, nbytes);
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memset(data, PYMEM_CLEANBYTE, nbytes);
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}
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/* at tail, write pad (SST bytes) and serialno (SST bytes) */
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tail = data + nbytes;
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memset(tail, FORBIDDENBYTE, SST);
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memset(tail, PYMEM_FORBIDDENBYTE, SST);
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#ifdef PYMEM_DEBUG_SERIALNO
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write_size_t(tail + SST, serialno);
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#endif
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@ -2204,7 +2190,7 @@ _PyMem_DebugRawCalloc(void *ctx, size_t nelem, size_t elsize)
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/* The debug free first checks the 2*SST bytes on each end for sanity (in
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particular, that the FORBIDDENBYTEs with the api ID are still intact).
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Then fills the original bytes with DEADBYTE.
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Then fills the original bytes with PYMEM_DEADBYTE.
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Then calls the underlying free.
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*/
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static void
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@ -2222,7 +2208,7 @@ _PyMem_DebugRawFree(void *ctx, void *p)
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_PyMem_DebugCheckAddress(api->api_id, p);
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nbytes = read_size_t(q);
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nbytes += PYMEM_DEBUG_EXTRA_BYTES;
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memset(q, DEADBYTE, nbytes);
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memset(q, PYMEM_DEADBYTE, nbytes);
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api->alloc.free(api->alloc.ctx, q);
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}
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@ -2264,14 +2250,14 @@ _PyMem_DebugRawRealloc(void *ctx, void *p, size_t nbytes)
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*/
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if (original_nbytes <= sizeof(save)) {
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memcpy(save, data, original_nbytes);
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memset(data - 2 * SST, DEADBYTE,
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memset(data - 2 * SST, PYMEM_DEADBYTE,
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original_nbytes + PYMEM_DEBUG_EXTRA_BYTES);
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}
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else {
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memcpy(save, data, ERASED_SIZE);
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memset(head, DEADBYTE, ERASED_SIZE + 2 * SST);
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memset(head, PYMEM_DEADBYTE, ERASED_SIZE + 2 * SST);
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memcpy(&save[ERASED_SIZE], tail - ERASED_SIZE, ERASED_SIZE);
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memset(tail - ERASED_SIZE, DEADBYTE,
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memset(tail - ERASED_SIZE, PYMEM_DEADBYTE,
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ERASED_SIZE + PYMEM_DEBUG_EXTRA_BYTES - 2 * SST);
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}
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@ -2293,10 +2279,10 @@ _PyMem_DebugRawRealloc(void *ctx, void *p, size_t nbytes)
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write_size_t(head, nbytes);
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head[SST] = (uint8_t)api->api_id;
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memset(head + SST + 1, FORBIDDENBYTE, SST-1);
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memset(head + SST + 1, PYMEM_FORBIDDENBYTE, SST-1);
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tail = data + nbytes;
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memset(tail, FORBIDDENBYTE, SST);
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memset(tail, PYMEM_FORBIDDENBYTE, SST);
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#ifdef PYMEM_DEBUG_SERIALNO
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write_size_t(tail + SST, block_serialno);
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#endif
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@ -2320,7 +2306,8 @@ _PyMem_DebugRawRealloc(void *ctx, void *p, size_t nbytes)
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if (nbytes > original_nbytes) {
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/* growing: mark new extra memory clean */
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memset(data + original_nbytes, CLEANBYTE, nbytes - original_nbytes);
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memset(data + original_nbytes, PYMEM_CLEANBYTE,
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nbytes - original_nbytes);
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}
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return data;
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@ -2399,7 +2386,7 @@ _PyMem_DebugCheckAddress(char api, const void *p)
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* the tail could lead to a segfault then.
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*/
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for (i = SST-1; i >= 1; --i) {
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if (*(q-i) != FORBIDDENBYTE) {
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if (*(q-i) != PYMEM_FORBIDDENBYTE) {
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msg = "bad leading pad byte";
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goto error;
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}
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@ -2408,7 +2395,7 @@ _PyMem_DebugCheckAddress(char api, const void *p)
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nbytes = read_size_t(q - 2*SST);
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tail = q + nbytes;
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for (i = 0; i < SST; ++i) {
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if (tail[i] != FORBIDDENBYTE) {
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if (tail[i] != PYMEM_FORBIDDENBYTE) {
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msg = "bad trailing pad byte";
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goto error;
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}
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@ -2448,7 +2435,7 @@ _PyObject_DebugDumpAddress(const void *p)
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fprintf(stderr, " The %d pad bytes at p-%d are ", SST-1, SST-1);
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ok = 1;
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for (i = 1; i <= SST-1; ++i) {
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if (*(q-i) != FORBIDDENBYTE) {
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if (*(q-i) != PYMEM_FORBIDDENBYTE) {
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ok = 0;
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break;
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}
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@ -2457,11 +2444,11 @@ _PyObject_DebugDumpAddress(const void *p)
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fputs("FORBIDDENBYTE, as expected.\n", stderr);
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else {
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fprintf(stderr, "not all FORBIDDENBYTE (0x%02x):\n",
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FORBIDDENBYTE);
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PYMEM_FORBIDDENBYTE);
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for (i = SST-1; i >= 1; --i) {
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const uint8_t byte = *(q-i);
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fprintf(stderr, " at p-%d: 0x%02x", i, byte);
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if (byte != FORBIDDENBYTE)
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if (byte != PYMEM_FORBIDDENBYTE)
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fputs(" *** OUCH", stderr);
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fputc('\n', stderr);
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}
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@ -2476,7 +2463,7 @@ _PyObject_DebugDumpAddress(const void *p)
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fprintf(stderr, " The %d pad bytes at tail=%p are ", SST, (void *)tail);
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ok = 1;
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for (i = 0; i < SST; ++i) {
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if (tail[i] != FORBIDDENBYTE) {
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if (tail[i] != PYMEM_FORBIDDENBYTE) {
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ok = 0;
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break;
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}
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@ -2485,12 +2472,12 @@ _PyObject_DebugDumpAddress(const void *p)
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fputs("FORBIDDENBYTE, as expected.\n", stderr);
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else {
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fprintf(stderr, "not all FORBIDDENBYTE (0x%02x):\n",
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FORBIDDENBYTE);
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PYMEM_FORBIDDENBYTE);
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for (i = 0; i < SST; ++i) {
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const uint8_t byte = tail[i];
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fprintf(stderr, " at tail+%d: 0x%02x",
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i, byte);
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if (byte != FORBIDDENBYTE)
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if (byte != PYMEM_FORBIDDENBYTE)
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fputs(" *** OUCH", stderr);
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fputc('\n', stderr);
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}
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