[issue17016] _sre: avoid relying on pointer overflow

2013-03-11 Thread Nickolai Zeldovich
Nickolai Zeldovich added the comment: I get an HTTP error when trying to upload another patch through Rietveld, so here's a revised patch that avoids the need for Py_uintptr_t (thanks Serhiy). -- Added file: http://bugs.python.org/file29379/pp-3.

[issue17016] _sre: avoid relying on pointer overflow

2013-03-11 Thread Nickolai Zeldovich
Nickolai Zeldovich added the comment: I just submitted the contributor form -- thanks for the reminder. -- ___ Python tracker <http://bugs.python.org/issue17

[issue17016] _sre: avoid relying on pointer overflow

2013-03-10 Thread Nickolai Zeldovich
Nickolai Zeldovich added the comment: Sorry for the delay. Attached is an updated patch that should fix all of the issues mentioned in this bug report. -- Added file: http://bugs.python.org/file29368/pp-2.patch ___ Python tracker <h

[issue17016] _sre: avoid relying on pointer overflow

2013-01-23 Thread Nickolai Zeldovich
Nickolai Zeldovich added the comment: For an unsigned int offset, see my original bug report: gcc eliminates the check altogether, since offset >= 0 by definition. -- ___ Python tracker <http://bugs.python.org/issu

[issue17016] _sre: avoid relying on pointer overflow

2013-01-23 Thread Nickolai Zeldovich
Nickolai Zeldovich added the comment: Lines 2777 and 3111 do indeed look suspect, because gcc can compile (ptr + offset < ptr) into (offset < 0): nickolai@sahara:/tmp$ cat x.c void bar(); void foo(char* ptr, int offset) { if (ptr + offset < ptr) bar(); } nickolai@sahara:/tmp

[issue17016] _sre: avoid relying on pointer overflow

2013-01-22 Thread Nickolai Zeldovich
New submission from Nickolai Zeldovich: Modules/_sre.c relies on pointer overflow in 5 places to check that the supplied offset does not cause wraparound when added to a base pointer; e.g.: SRE_CODE prefix_len; GET_ARG; prefix_len = arg