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From: "xdje42 at gmail dot com" <sourceware-bugzilla@sourceware.org> To: gdb-prs@sourceware.org Subject: [Bug python/18175] New: gdb.parse_and_eval should un-lazy results Date: Sun, 29 Mar 2015 21:52:00 -0000 [thread overview] Message-ID: <bug-18175-4717@http.sourceware.org/bugzilla/> (raw) https://sourceware.org/bugzilla/show_bug.cgi?id=18175 Bug ID: 18175 Summary: gdb.parse_and_eval should un-lazy results Product: gdb Version: HEAD Status: NEW Severity: normal Priority: P2 Component: python Assignee: unassigned at sourceware dot org Reporter: xdje42 at gmail dot com gdb.parse_and_eval should un-lazy its results. Otherwise the following can happen. Try 1: (gdb) py foo = gdb.parse_and_eval ("*(char*) $sp") (gdb) x/b $sp 0x7fffffffe1c0: 0 (gdb) py print foo 0 '\000' (gdb) set *(char*) $sp = 42 (gdb) x/b $sp 0x7fffffffe1c0: 42 (gdb) py print foo 0 '\000' <<<<< expected result Try 2: (gdb) py foo = gdb.parse_and_eval ("*(char*) $sp") (gdb) set *(char*) $sp = 43 (gdb) py print foo 43 '+' <<<<< Ugh. (gdb) Note that in the first example, the "py print foo" before modifying memory is sufficient to un-lazy the value. I point this out to show that if we don't make this change then debugging such things can be nasty: a simple "print" can modify program behaviour. Guile's parse-and-eval has the same issue. -- You are receiving this mail because: You are on the CC list for the bug.
next reply other threads:[~2015-03-28 22:13 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-03-29 21:52 xdje42 at gmail dot com [this message] 2022-06-06 23:30 ` [Bug python/18175] " tromey at sourceware dot org
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