IfcConvert segfault with SVG output

[brunopostle]

At some point in the last few months my builds of IfcConvert started segfaulting when outputting SVG. Other output formats seem to be ok . Obviously this is a problem with my build environment, but I can't figure it out and need suggestions for somewhere to look next. Note that all my builds start with a clean git source tree.

The segfault happens almost immediately:

$ IfcConvert simple.ifc simple.svg
IfcOpenShell IfcConvert 0.7.0 (OCC 7.5.0)
Scanning file...
Done scanning file   
Parsing input file took 0 seconds
Creating geometry...
Segmentation fault (core dumped)

The stack trace doesn't show much:

           PID: 187314 (IfcConvert)
           UID: 1000 (bruno)
           GID: 1000 (bruno)
        Signal: 11 (SEGV)
     Timestamp: Fri 2022-04-22 18:32:33 BST (4h 57min ago)
  Command Line: IfcConvert simple.ifc simple.svg
    Executable: /usr/bin/IfcConvert
 Control Group: /user.slice/user-1000.slice/user@1000.service/app.slice/app-org.gnome.Terminal.slice/vte-spawn-a1d1f3c7-83f3-4025-acd1-d38041226e9e.scope
          Unit: user@1000.service
     User Unit: vte-spawn-a1d1f3c7-83f3-4025-acd1-d38041226e9e.scope
         Slice: user-1000.slice
     Owner UID: 1000 (bruno)
       Boot ID: ddc7641d67c9404db36f63f1a8d31b20
    Machine ID: b1abb895ecaa4632b1660d4d0420f492
      Hostname: cluck
       Storage: /var/lib/systemd/coredump/core.IfcConvert.1000.ddc7641d67c9404db36f63f1a8d31b20.187314.1650648753000000.zst (present)
     Disk Size: 2.9M
       Message: Process 187314 (IfcConvert) of user 1000 dumped core.

                Found module linux-vdso.so.1 with build-id: 1e289edaaab9e832320ae02a0c5d0953c38b2de1
                Found module libftoa.so.0.4 with build-id: 29f1f511a0922a9bc87e20433fba76da15214570
                Found module libbz2.so.1 with build-id: 19ce300b78962ee0b113afb0f1016727a2f3c37b
                Found module libsz.so.2 with build-id: c69bcb83945ff4e25be01fc8e04ffb0545d1308e
                Found module libbuffer.so.0.4 with build-id: cfbb4dac66805927a7d9880ac0276ab210591a85
                Found module libpcre.so.1 with build-id: fcbdb4731e50f20a47b62341a6841dd616fe495d
                Found module libUTF.so.0.4 with build-id: b233a769b5825d77b9418f23f6f246251053aad1
                Found module libboost_iostreams.so.1.76.0 with build-id: bcf2126fab7972d12b5b9dc1b9e35ca0fa3673b5
                Found module libTKOffset.so.7 with build-id: 2130b06d825c391745432ce1f4bbb55f49f495eb
                Found module libTKFillet.so.7 with build-id: 100a90a339ca5f5ff19305865cb285b2ad6b97da
                Found module libTKBool.so.7 with build-id: 2b5ad243ed1ef4fa4dd2cbdbf963fa5f7ddfd6d0
                Found module libTKSTEPBase.so.7 with build-id: fdad9fef075576b11b2a68ca617f732e78d75dba
                Found module libTKSTEP209.so.7 with build-id: 488b6b4e720dfe63fcf3e352abaa92f004486703
                Found module libTKSTEPAttr.so.7 with build-id: 4d19b4a8000b6d299589cb6756c4d9dda00d0beb
                Found module ld-linux-x86-64.so.2 with build-id: 0414018caaea84ae28b5cac3374e2de68eaeecf8
                Found module libtbbmalloc.so.2 with build-id: ed5c024c117d607c4a753c0f263d60322571232b
                Found module libtbb.so.2 with build-id: e19254d0be6fc6d486d8ff3252922925d5d1dd93
                Found module libhdf5.so.103 with build-id: db9f5d317e0b2f95e9115f7525d441a1e59c594b
                Found module libhdf5_cpp.so.103 with build-id: f62176e6749ac02a5bfcae4505104f76bc9f7f42
                Found module libTKHLR.so.7 with build-id: b7026d5f43b93d5e97205c3377275b8e78146f2a
                Found module libTKBO.so.7 with build-id: 73dd798f7de93a7028479acac18d7fb7bfa2e9df
                Found module libTKPrim.so.7 with build-id: 33bd52c7520f0ef192f5eb2fe723bed9eb74c1ed
                Found module libTKShHealing.so.7 with build-id: cca40b008c763ae5e59fc3259e73212e13b58b96
                Found module libTKGeomAlgo.so.7 with build-id: cd09e1fb2ce1c5fec90957d14ff93372a7c50b0c
                Found module libTKGeomBase.so.7 with build-id: 661f188a75aa73c215f9ee86fd497cb6c3a90fbf
                Found module liblzma.so.5 with build-id: 8f6112440d7c7e991ffa27ef23ceb6bd6a6ed4a0
                Found module libz.so.1 with build-id: 5903f5c355c264403e4e7cdc66779584425ca3b8
                Found module libc.so.6 with build-id: 5d63c4327ba6cdd1e8b99eb1c0a9f056a98c67e1
                Found module libgcc_s.so.1 with build-id: 0028b8616fa79ea1496e4812c3fc9c7bf9607a56
                Found module libm.so.6 with build-id: 1586854d78f3048d2f112e36b97e6db246b60fa0
                Found module libstdc++.so.6 with build-id: 455be2588680c3ff57e3a7defe212a13e2efdbd1
                Found module libOpenCOLLADAStreamWriter.so.0.4 with build-id: 84bcd2bacfb2b2344f9c64a9f25ac1dc52e6d05e
                Found module libOpenCOLLADABaseUtils.so.0.4 with build-id: 8b53d194ef4f05c3411bb84308c32423eaf42c7b
                Found module libIfcParse.so.0.6 with build-id: 5e82201ef553ae3b8d16b3025d26c0648b59427b
                Found module libIfcGeom.so.0.6 with build-id: 9466b90c9cb444a612fb7577e04bd835a50b6155
                Found module libboost_program_options.so.1.76.0 with build-id: 465ffe68f6e5ab2c75c8b4248482d11e1e1e1446
                Found module libTKIGES.so.7 with build-id: 6ccc056660859b9fd6dcbde7fcb14c6d1c530fa6
                Found module libTKXSBase.so.7 with build-id: 97104cd7e0425094d0a9402065e85dea8d73f453
                Found module libTKSTEP.so.7 with build-id: 4c55919a222fe817c54a3fae697fe4b047c8affc
                Found module libTKMesh.so.7 with build-id: 8dbb10349ac743025a7efb73178f1b9428aeaa7a
                Found module libTKTopAlgo.so.7 with build-id: 3d8c88f49d69963cf0e8bd63570338b62112ef14
                Found module libTKG2d.so.7 with build-id: 5fba61eabe40936624b7da6645abd2663065973e
                Found module libTKG3d.so.7 with build-id: 7d854d164eedb96f95eed6af09986ec8ddf19017
                Found module libTKBRep.so.7 with build-id: 9f64089abecc56acacf275cfd981396f4e4c354e
                Found module libTKMath.so.7 with build-id: 232fcc30255baa9c2d2f33985d3eeb6bc620e844
                Found module libTKernel.so.7 with build-id: d2ebdcf07ab63b53eea18023a62cc8dc9cc72f2c
                Found module libSerializers.so.0.6 with build-id: aea81741623ba13f5239999592534ffe1210ffc2
                Found module libxml2.so.2 with build-id: 7f7c4a4c85206200336c641203ee60c41e6b7231
                Found module IfcConvert with build-id: 38751ba35b0feb3922a245728859821d0b78d72b
                Stack trace of thread 187314:
                #0  0x00007fc691f89f64 _ZN7IfcGeom10KernelIfc47convertEPKN4Ifc418IfcObjectPlacementER7gp_Trsf (libIfcGeom.so.0.6 + 0x2e1f64)
                #1  0x00007fc691f9a934 _ZN7IfcGeom27IteratorImplementation_Ifc410get_objectEi (libIfcGeom.so.0.6 + 0x2f2934)
                #2  0x00007fc691f94329 _ZN7IfcGeom27IteratorImplementation_Ifc43getEv (libIfcGeom.so.0.6 + 0x2ec329)
                #3  0x0000555cf7a868d1 main (IfcConvert + 0x448d1)
                #4  0x00007fc68b205560 __libc_start_call_main (libc.so.6 + 0x2d560)
                #5  0x00007fc68b20560c __libc_start_main@@GLIBC_2.34 (libc.so.6 + 0x2d60c)
                #6  0x0000555cf7a8a5b5 _start (IfcConvert + 0x485b5)

These are the dependencies I am using to build, all standard fedora packages:

cmake-3.22.2
gcc-c++-11.2.1
boost-1.76.0
libicu-69.1
openCOLLADA-1.6.68
pcre-8.45
python3-3.10.4
swig-4.0.2
libxml2-2.9.13
tbb-2020.3
blender-3.1.2
opencascade-7.5.0
hdf5-1.10.7
json-3.10.5
CGAL-5.3.1
gmp-6.2.0
mpfr-4.1.0

Build flags are:

-DENABLE_BUILD_OPTIMIZATIONS=ON -DCMAKE_CXX_FLAGS=-lxml2 -DBUILD_SHARED_LIBS=1 \
-DGLTF_SUPPORT=ON -DHDF5_SUPPORT=ON -DUSE_MMAP=ON

[aothms]

So the segfault is in

Frame 0: IfcGeom::KernelIfc4::convert(Ifc4::IfcObjectPlacement const*, gp_Trsf&)

Frame 1: https://github.com/IfcOpenShell/IfcOpenShell/blob/v0.7.0/src/ifcgeom/IfcGeomIteratorImplementation.h#L973

Within the block specific to ELEMENT_HIERARCHY which is indeed specific to SVG

https://github.com/IfcOpenShell/IfcOpenShell/blob/v0.7.0/src/ifcconvert/IfcConvert.cpp#L815

I wouldn't be convinced that it's due to your build system. It might be something specific to the files you feed it. Or perhaps a compiler version tripping over some undefined behaviour.

[brunopostle]

Thanks, I thought that I was seeing segfaults with other files, but actually IfcConvert is producing SVG files with and <style> sections but no other data. Is there one of the IFC files in the 0.7.0 sources that consistently produces SVG output that I can test with?

Attached is the IFC file from the stack trace above
simple.ifc.txt
.

[aothms]

The command line for SVG is also a bit magical perhaps, how do you precisely invoke IfcConvert?

[brunopostle]

$ IfcConvert simple.ifc simple.svg --print-space-names --print-space-areas --exclude entities ifcspace
IfcOpenShell IfcConvert 0.7.0 (OCC 7.5.0)
Scanning file...
Done scanning file   
Parsing input file took 1 second
Creating geometry...
Segmentation fault (core dumped)

[aothms]

On Duplex.ifc [0] I get good results.

Duplex_A_20110907_optimized.ifc -yv d.svg --svg-project --door-arcs --print-space-names --print-space-areas --section-height-from-storeys --bound=1024x1024 --exclude entities IfcOpeningElement

[0] https://portal.nibs.org/files/wl/?id=O9inoVWDytV4P3UTS7iIdqhVKcTyVlcs

[aothms]

Ok, the issue was the aggregated wall

#36=IFCWALL('2q_0TfKbH59xaXpnEzTytx',$,'default/exterior',$,$,$,$,$,$);

The ELEMENT_HIERARCHY setting broke on the empty placement. The convention is that children of {aggregation, containment, voiding, filling, ...} have their object placement set relative to their host element.

It's a bit of a bug that we don't use a property maybe<> type yet for optional entity instances so instead of a catchable exception we end up with a nullptr dereference.

Should be fixed now in this particular case.

[brunopostle]

Ok, that works fine here:

My generated IFC file with the same parameters segfaults:

$ IfcConvert simple.ifc -yv e.svg --svg-project --door-arcs --print-space-names --print-space-areas --section-height-from-storeys --bound=1024x1024 --exclude entities IfcOpeningElement
IfcOpenShell IfcConvert 0.7.0 (OCC 7.5.0)
Scanning file...
Done scanning file   
Parsing input file took 1 second
Creating geometry...
Segmentation fault (core dumped)

[brunopostle]

Thanks, building now... will close when I confirm the fix

I had trouble using the API to set positions of aggregated objects, so I ended-up setting an absolute position, I'll investigate

[Moult]

@brunopostle what issues did you have? The API for edit_object_placement should auto handle relative placements: https://github.com/IfcOpenShell/IfcOpenShell/blob/v0.7.0/src/ifcopenshell-python/ifcopenshell/api/geometry/edit_object_placement.py#L77-L97

[brunopostle]

@Moult I was creating an aggregate and assigning elements, but couldn't understand why geometry.edit_object_placement on the parent didn't move anything, so I ended up placing each child. I can see now that my problem is likely that the parent never had a placement in the first place. So the API is probably doing the best it can in the circumstances.

[Moult]

@brunopostle cheers, note that there is a should_transform_children setting there which allows you to toggle whether children should move when updating the placement of a parent.

[brunopostle]

@Moult thanks, I can see I need to make a few changes.

Closing this bug, IfcConvert SVG output is working again after a rebuild: