Stacktrace disappear on FreeBSD

[iblislin]

Hi,
I found that there are some stacktrace messages missing on FreeBSD.

julia> 2^-1
ERROR: DomainError:
Stacktrace:
 [1] internal_pow(::Int64, ::Type{Val{-1}}) at ./intfuncs.jl:204

julia> versioninfo()
Julia Version 0.6.0-dev.2921
Commit 12624fb80a* (2017-02-23 05:41 UTC)
Platform Info:
  OS: FreeBSD (amd64-unknown-freebsd12.0)
  CPU: Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT NO_AFFINITY SANDYBRIDGE)
  LAPACK: libopenblasp
  LIBM: libm
  LLVM: libLLVM-3.8.1 (ORCJIT, sandybridge)

And ... on Linux:

julia> versioninfo()
Julia Version 0.6.0-dev.2856
Commit 34b39f8718 (2017-02-19 00:02 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Xeon(R) CPU E3-1231 v3 @ 3.40GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
  LAPACK: libopenblas64_
  LIBM: libopenlibm
  LLVM: libLLVM-3.9.1 (ORCJIT, haswell)
  
julia> 2^-1
ERROR: DomainError:
Cannot raise an integer x to a negative power -n.
Make x a float by adding a zero decimal (e.g. 2.0^-n instead of 2^-n), or write 1/x^n, float(x)^-n, or (x//1)^-n.
Stacktrace:
 [1] power_by_squaring(::Int64, ::Int64) at ./intfuncs.jl:170
 [2] internal_pow(::Int64, ::Type{Val{-1}}) at ./intfuncs.jl:204
 [3] ^(::Int64, ::Type{T} where T) at ./intfuncs.jl:203

Quote from https://julia.iblis.cnmc.tw/#/builders/1/builds/152/steps/6/logs/stdio :

Error in testset replutil:

Test Failed

  Expression: contains(err_str, "Cannot raise an integer x to a negative power -n")

Error in testset cmdlineargs:

Test Failed

  Expression: contains(bt, "include_from_node1")

Error in testset cmdlineargs:

Test Failed

  Expression: contains(bt, "include_from_node1(::String) at $(joinpath(".", "loading.jl"))")

Error in testset cmdlineargs:

Error During Test

  Test threw an exception of type ErrorException

  Expression: length(lno.captures) == 1

  type Void has no field captures

  Stacktrace:

   [1] length at ./checked.jl:222 [inlined]

   [2] map(::Base.Distributed.##38#43, ::Array{Any,1}) at ./essentials.jl:186

Error in testset cmdlineargs:

Error During Test

  Test threw an exception of type ErrorException

  Expression: parse(Int, lno.captures[1]) > 0

  type Void has no field captures

  Stacktrace:

   [1] length at ./checked.jl:222 [inlined]

   [2] map(::Base.Distributed.##38#43, ::Array{Any,1}) at ./essentials.jl:186

Any idea about a starting point to fix this?

[tkelman]

guessing, but what libunwind are you using?

[iblislin]

From system: https://julia.iblis.cnmc.tw/#/builders/1/builds/152/steps/0/logs/pkg-libunwind

[iblislin]

libunwind-20121006_2 is actually version 1.1 .

[tkelman]

can you try with the source build from deps? that has a bunch of patches.

[iblislin]

Ok, I tried it. It make the messages more, but it's still not enough to pass the testing.

julia> 2^-1
ERROR: DomainError:
Stacktrace:
 [1] internal_pow(::Int64, ::Type{Val{-1}}) at ./intfuncs.jl:207
 [2] eval_user_input(::Any, ::Base.REPL.REPLBackend) at ./REPL.jl:66
 [3] macro expansion at ./REPL.jl:97 [inlined]
 [4] (::Base.REPL.##1#2{Base.REPL.REPLBackend})() at ./event.jl:73

It missed [1] power_by_squaring(::Int64, ::Int64) at ./intfuncs.jl:170 line.

[iblislin]

By observing the result of test-cmdlineargs, I found this issue only popup via precompile=yes.

$ cat foo.jl 
module FooBar
error("break me")
end

$ ../julia --precompile=yes foo.jl
ERROR: LoadError: break me
while loading /usr/home/iblis/git/julia/tmp/foo.jl, in expression starting on line 2

$ ../julia --precompile=no foo.jl 
ERROR: LoadError: break me
Stacktrace:
 [1] error(::String) at ./error.jl:21
 [2] include_from_node1(::String) at ./loading.jl:539
 [3] include(::String) at ./sysimg.jl:14
 [4] process_options(::Base.JLOptions) at ./client.jl:305
 [5] _start() at ./client.jl:371
while loading /usr/home/iblis/git/julia/tmp/foo.jl, in expression starting on line 2

Something wrong in codegen?

[iblislin]

Got tons of error with gdb. Is this related?

└─[iblis@abeing]% gdb ../julia                                                                                         
GNU gdb 6.1.1 [FreeBSD]
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "amd64-marcel-freebsd"...
(gdb) run
Starting program: /usr/home/iblis/git/julia/julia
[New LWP 100795]
Error while reading shared library symbols:
Dwarf Error: wrong version in compilation unit header (is 4, should be 2) [in module /usr/local/lib/gcc49/libgcc_s.so.1]
[New Thread 804216000 (LWP 100795/julia)]
Error while reading shared library symbols:
Dwarf Error: wrong version in compilation unit header (is 4, should be 2) [in module /usr/local/lib/gcc49/libgcc_s.so.1]
Error while reading shared library symbols:
Dwarf Error: wrong version in compilation unit header (is 4, should be 2) [in module /usr/local/lib/gcc49/libgcc_s.so.1]
Error while reading shared library symbols:
Dwarf Error: wrong version in compilation unit header (is 4, should be 2) [in module /usr/local/lib/gcc49/libgcc_s.so.1]
Error while reading shared library symbols:
Dwarf Error: wrong version in compilation unit header (is 4, should be 2) [in module /usr/local/lib/gcc49/libgcc_s.so.1]
Error while reading shared library symbols:
...

[tkelman]

that's a really old version of gdb, is it possible to get anything newer?

[iblislin]

:-o ok, i will get one.

[iblislin]

I think I got the pain point, but no idea how to resolve it (I have no related background knowledge), here is my gdb.
The function dladdr return _init as the dli_sname. dli_sname is power_by_squring on linux(i guess) and the replutil.jl will render the expected error message and stacktrace.

[yuyichao]

I assume FreeBSD uses ELF so it probably has the same problem on linux that the internal symbol is not in the exported symbol and not returned by dladdr. On linux, this is worked around by the libunwind call below to use debug info/symbol table so you either need to see if the libunwind on FreeBSD support that too or find another way to get that info. Ideally we can ask LLVM about this since we are already using it to parse debug info though I didn't figure out how it works in 5mins before finding the libunwind function that works....

[iblislin]

Do these help?

• https://github.com/llvm-mirror/llvm/blob/master/tools/llvm-symbolizer/llvm-symbolizer.cpp
• http://llvm.org/docs/CommandGuide/llvm-symbolizer.html

( I'm just blindly googling...

[iblislin]

@yuyichao Would you point out how to do function pointer <-> address resolving in libunwind on linux?
I will dig into the code if i get free time this weekend.

[yuyichao]

julia/src/debuginfo.cpp

Line 1401 in 64409a0

if (!saddr && unw_get_proc_info_by_ip(unw_local_addr_space,