morning all,

I've been chasing a bug for several weeks now that I just can't seem to get my head around: symptoms are segfaults and complete crashes in pd (v0.40-2 vanilla) on linux/x86 [debian unstable, gcc 4.1.2]. gdb backtraces are available, and I've just recompiled using identical CFLAGS everywhere (-O3 -march=pentium-m -msse -msse2 -mfpmath=sse -ffast-math -funroll-loops), since I had feared that -malign-double might have been biting me, but this doesn't appear to have been the case...

Buglet the First (solved, kinda)

• description: [pool] and [readanysf~] don't play nicely together
• symptom: the (infamous) libc message on stderr when closing a patch: *** glibc detected *** free(): invalid pointer: 0x0823e46c ***
  • apparently caused by some goofiness with the flext delete() operator

(backtraces etc. available)

• solution (I think, thanks to the list archives):
  • compile both flext and readanysf~ with -DFLEXT_USE_CMEM
  • readanysf~ really seems to need FLEXT_USE_CMEM flext-globally (I can

provide a pretty complete and systematic list of the configurations I've tried: it's possible to compile and run successfully without FLEXT_USE_CMEM, but things break more or less randomly at runtime then: particularly, the "stop" message to readanysf~ segfaults pd)

• solution (I think, thanks to the list archives):
  • this seems to work for [pool] and [readanysf~], but...

Buglet the Second (please assist!)

• description: [fluid~] in abstractions crashes pd

  • having compiled flext with -DFLEXT_USE_CMEM, loading any abstraction containing a [fluid~] object causes pd to segfault (see below)

  • bug occurs even without any other externals loaded

  • oddly, I *can* create [fluid~]s by hand, (but not load them in an abstraction, which makes the object pretty useless, im(ns)ho)

  • any ideas why fluid_init() is trying to initialize this==NULL ?

    • this appears to be FLEXT_USE_CMEM related, since I didn't get these symptoms without FLEXT_USE_CMEM in flext itself

  • I can't just -UFLEXT_USE_CMEM for fluid~, because: (a) that would break readanysf~ if I did it flext-globally, and (b) if I undefine FLEXT_USE_CMEM only for fluid~, I get undefined linker symbols at runtime:

    /usr/local/lib/pd/extra/fluid~.pd_linux: \
    

    /usr/local/lib/pd/extra/fluid~.pd_linux: undefined symbol:
    _ZN19flext_root_single_ddlEPv
    fluid~: can't load library

  • would it help to fork the flext build procedure (again!), basically adding another library suffix for FLEXT_USE_CMEM, since its effects appear not to be restricted to the headers?

    • if the suffix were, say, 'c', where we now have:

    libflext-pd((_d)?.so|_[st]d?.a) we would get: libflext-pd((_c?d?).so|_[st]c?d?.a)

    • i know this is ugly, and I'm not even sure it would work, but I'm at my wits' end here... I hope somebody can shed some light on this for me...

Program received signal SIGSEGV, Segmentation fault. [Switching to Thread -1210693952 (LWP 24068)] 0xb7dcb589 in free () from /lib/tls/i686/cmov/libc.so.6 (gdb) backtrace #0 0xb7dcb589 in free () from /lib/tls/i686/cmov/libc.so.6 #1 0xb7d1e639 in delete_fluid_synth () from /usr/lib/libfluidsynth.so.1 #2 0x08237bd0 in ?? () #3 0x0811ace0 in mstack.5434 () #4 0xbfd76828 in ?? () #5 0xb7d47366 in fluid::fluid_init (this=0x0, argc=-1210746848, argv=0xb7caf730) at fluid/main.cpp:251 Previous frame inner to this frame (corrupt stack?)

marmosets, Bryan