http://llvm.org/bugs/show_bug.cgi?id=15784
I am writing frontend using lldb+python and completely blocked on this. I guess all Linux user/developers would be blocked if they are using trunk. Somebody please fix this issue. Thanks Samuel On Thu, Apr 18, 2013 at 10:24 AM, Thirumurthi, Ashok <[email protected]> wrote: > FYI > > -----Original Message----- > From: Thirumurthi, Ashok > Sent: Thursday, April 18, 2013 11:37 AM > To: 'Samuel Jacob' > Subject: RE: [lldb-dev] lldb fails to examine any variable with the message - > Interpreting the expression locally failed: Interpreter couldn't write to > memory > > Hi Samuel, > > Thanks for the test case. I can reproduce this using trunk with > lldb/tests/functionalities/inferior-crashing, and confirmed that there is no > existing bug report. For instance, the issue is distinct from > http://llvm.org/bugs/show_bug.cgi?id=15671. > > After the crash, the back-trace is correct, and "register read -a" dumps the > register set. The expression parser should generate IR that the LLDB > interpreter can use to read from the address of argc in the inferior. So, > there is no design requirement to inject code into the inferior to evaluate > the expression. I suspect that the write is related to a temporary that is > used to store the result of the read, but it may be possible to rework the > expression interpreter to eliminate the write. > > The attached patch modifies the existing test case to reproduce the issue > that you've raised (and also checks the register read). If you don't mind, > I'll log a bugzilla for this in order to cross-reference it with the failing > test. I've marked the test as xfail on Darwin as well. I'll let folks chime > in if it's an xpass... > > FYI, when run under our test harness, this test fails with 'use of undeclared > identifier 'argc''. I can reproduce this second issue from the command line > by issuing 'expr argc' twice, at which point the process is no longer in a > limbo state. Thanks again, > > - Ashok > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of Samuel Jacob > Sent: Wednesday, April 17, 2013 11:53 PM > To: lldb-dev; Malea, Daniel > Subject: Re: [lldb-dev] lldb fails to examine any variable with the message - > Interpreting the expression locally failed: Interpreter couldn't write to > memory > > Hi Dan, > > Can you please check this? > > Thanks > Samuel > > On Wed, Apr 17, 2013 at 4:21 PM, Samuel Jacob <[email protected]> wrote: >> lldb build from trunk running on Ubuntu 12.04 is not able examine any >> variable. >> >> $cat test1.c >> int main(int argc, char argv[]) >> { >> char *crash=0; >> >> *crash = 0; >> return 0; >> } >> >> $gcc -O0 -g3 ./test1.c >> >> $lldb ~/a.out >> Current executable set to '/mts/home3/jacobs/a.out' (x86_64). >> >> (lldb) run >> Process 16615 launched: '/mts/home3/jacobs/a.out' (x86_64) Process >> 16615 stopped >> * thread #1: tid = 0x40e7, 0x00000000004004cb a.out`main(argc=1, >> argv=0x00007fff336ad2a8) + 23 at test1.c:5, stop reason = invalid >> address >> frame #0: 0x00000000004004cb a.out`main(argc=1, >> argv=0x00007fff336ad2a8) + 23 at test1.c:5 >> 2 { >> 3 char *crash=0; >> 4 >> -> 5 *crash = 0; >> 6 return 0; >> 7 } >> (lldb) p argc >> error: Interpreting the expression locally failed: Interpreter >> couldn't write to memory >> >> But before crashing If a breakpoint was setup, lldb stops at the >> breakpoint and works fine. >> >> Is it a known issue or should a file a bug report? >> >> Samuel > _______________________________________________ > lldb-dev mailing list > [email protected] > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev > > _______________________________________________ > lldb-dev mailing list > [email protected] > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev > _______________________________________________ lldb-dev mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
