From: Nicholas Nethercote Date: Wed, 17 Oct 2007 22:29:08 +0000 (+0000) Subject: clarify a paragraph X-Git-Tag: svn/VALGRIND_3_3_0~192 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1fe5f40db44a0732692ff8caa77c5117cba2995f;p=thirdparty%2Fvalgrind.git clarify a paragraph git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7015 --- diff --git a/docs/xml/manual-core.xml b/docs/xml/manual-core.xml index 3fb02d9863..6ff0c9bdb9 100644 --- a/docs/xml/manual-core.xml +++ b/docs/xml/manual-core.xml @@ -105,18 +105,19 @@ and less confusing error reports. Chances are you're set up like this already, if you intended to debug your program with GNU gdb, or some other debugger. -This paragraph applies only if you plan to use Memcheck: On rare -occasions, optimisation levels at -O2 -and above have been observed to generate code which fools Memcheck into -wrongly reporting uninitialised value errors. We have looked in detail -into fixing this, and unfortunately the result is that doing so would -give a further significant slowdown in what is already a slow tool. So -the best solution is to turn off optimisation altogether. Since this -often makes things unmanagably slow, a reasonable compromise is to use +If you are planning to use Memcheck: On rare +occasions, compiler optimisations (at -O2 +and above, and sometimes -O1) have been +observed to generate code which fools Memcheck into wrongly reporting +uninitialised value errors, or missing uninitialised value errors. We have +looked in detail into fixing this, and unfortunately the result is that +doing so would give a further significant slowdown in what is already a slow +tool. So the best solution is to turn off optimisation altogether. Since +this often makes things unmanagably slow, a reasonable compromise is to use -O. This gets you the majority of the -benefits of higher optimisation levels whilst keeping relatively small -the chances of false complaints from Memcheck. All other tools (as far -as we know) are unaffected by optimisation level. +benefits of higher optimisation levels whilst keeping relatively small the +chances of false positives or false negatives from Memcheck. All other +tools (as far as we know) are unaffected by optimisation level. Valgrind understands both the older "stabs" debugging format, used by gcc versions prior to 3.1, and the newer DWARF2 and DWARF3 formats