translate helloworld.cc

[ctaggart]

#include <octave/oct.h>

DEFUN_DLD (helloworld, args, nargout,
           "Hello World Help String")
{
  octave_stdout << "Hello World has "
                << args.length () << " input arguments and "
                << nargout << " output arguments.\n";

  return octave_value_list ();
}

2017-09-26 troubleshooting ideas

https://github.com/ctaggart/octh_examples/blob/master/src/lib.rs

• mkoctfile on Linux and record gcc calls
• create oct file using just gcc
• get rid of macros and use separate functions
• give status to Octave maintainers and seek help
• find out if with the layout test failing 19 failed layout tests #23 7 layout tests failing on Linux #38 all bets are off
• find out the use of octh::root::std::string is wrong
• figure out how to gdb debug from Octave itself

[ctaggart]

Looks like the exported function from helloworld.oct when compiled from helloworld.cc is Ghelloworld.

C:\Octave> $env:path="C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\VC\Tools\MSVC\14.10.25017\bin\HostX86\x86;$env:path"

C:\Octave> dumpbin /exports helloworld.oct
Microsoft (R) COFF/PE Dumper Version 14.10.25019.0
Copyright (C) Microsoft Corporation.  All rights reserved.


Dump of file helloworld.oct

File Type: DLL

  Section contains the following exports for helloworld.oct

    00000000 characteristics
    58F53BC4 time date stamp Mon Apr 17 17:03:48 2017
        0.00 version
           1 ordinal base
          23 number of functions
          23 number of names

    ordinal hint RVA      name

          1    0 00001570 Ghelloworld
          2    1 00001440 _Z11FhelloworldRK17octave_value_listi
          3    2 00017200 _ZN10dim_vectorD1Ev = _ZN9__gnu_cxx13stdio_filebufIwSt11char_traitsIwEEC1EiSt13_Ios_Openmodey
          4    3 000174F0 _ZN12octave_value16fast_elem_insertEiRKS_
          5    4 00017580 _ZN13string_vectorD0Ev = _ZN9__gnu_cxx13stdio_filebufIwSt11char_traitsIwEED2Ev
          6    5 000176A0 _ZN13string_vectorD1Ev
          7    6 000177D0 _ZN17octave_base_value12unique_cloneEv
          8    7 000177E0 _ZN5ArrayI12octave_valueED0Ev
          9    8 000178D0 _ZN5ArrayI12octave_valueED1Ev
         10    9 000179B0 _ZN5ArrayISsED0Ev
         11    A 00017AD0 _ZN5ArrayISsED1Ev = _ZN9__gnu_cxx18stdio_sync_filebufIcSt11char_traitsIcEED1Ev
         12    B 000845C0 _ZTI12octave_value
         13    C 000845D0 _ZTI13string_vector
         14    D 000845F0 _ZTI5ArrayI12octave_valueE
         15    E 00084600 _ZTI5ArrayISsE
         16    F 000856F0 _ZTS12octave_value
         17   10 00085700 _ZTS13string_vector
         18   11 00085710 _ZTS5ArrayI12octave_valueE
         19   12 00085730 _ZTS5ArrayISsE
         20   13 00086E60 _ZTV12octave_value
         21   14 00086E80 _ZTV13string_vector
         22   15 00086EC0 _ZTV5ArrayI12octave_valueE
         23   16 00086F00 _ZTV5ArrayISsE

[ctaggart]

So it looks like the Ghelloworld is the "installer function".

From C:\Octave\Octave-4.2.1\include\octave-4.2.1\octave\defun-int.h

#  define DEFINE_FUN_INSTALLER_FUN(name, doc)                   \
  DEFINE_FUNX_INSTALLER_FUN(#name, F ## name, G ## name, doc)
#endif

#define DEFINE_FUNX_INSTALLER_FUN(name, fname, gname, doc)              \
  extern "C"                                                            \
  OCTAVE_EXPORT                                                         \
  octave_function *                                                     \
  gname (const octave::dynamic_library& shl, bool relative)             \
  {                                                                     \
    check_version (OCTAVE_API_VERSION, name);                           \
                                                                        \
    octave_dld_function *fcn                                            \
      = octave_dld_function::create (fname, shl, name, doc);            \
                                                                        \
    if (relative)                                                       \
      fcn->mark_relative ();                                            \
                                                                        \
    return fcn;                                                         \
  }

[ctaggart]

The related sections of lib.rs:

    pub struct octave_function {
        pub _bindgen_opaque_blob: [u64; 7usize],
    }

    pub struct octave_dld_function {
        pub _bindgen_opaque_blob: [u64; 14usize],
    }

    extern "C" {
        #[link_name =
              "_ZN19octave_dld_function6createEPF17octave_value_listRKS0_iERKN6octave15dynamic_libraryERKSsSA_"]
        pub fn octave_dld_function_create(ff: root::octave_builtin_fcn,
                                          shl:
                                              *const root::octave::dynamic_library,
                                          nm: *const root::std::string,
                                          ds: *const root::std::string)
         -> *mut root::octave_dld_function;
    }

    impl octave_dld_function {
        #[inline]
        pub unsafe fn create(ff: root::octave_builtin_fcn,
                             shl: *const root::octave::dynamic_library,
                             nm: *const root::std::string,
                             ds: *const root::std::string)
         -> *mut root::octave_dld_function {
            octave_dld_function_create(ff, shl, nm, ds)
        }
        #[inline]
        pub unsafe fn register_type() { octave_dld_function_register_type() }
        #[inline]
        pub unsafe fn new(ff: root::octave_builtin_fcn,
                          shl: *const root::octave::dynamic_library,
                          nm: *const root::std::string,
                          ds: *const root::std::string) -> Self {
            let mut __bindgen_tmp = ::std::mem::uninitialized();
            octave_dld_function_octave_dld_function(&mut __bindgen_tmp, ff,
                                                    shl, nm, ds);
            __bindgen_tmp
        }
    }

[ctaggart]

I'm currently running into this error and I'm not sure how to troubleshoot:

C:\Users\camer\rs\octh_helloworld [master +5 ~0 -0 !]> cargo build
   Compiling winapi v0.2.8
   Compiling libc v0.2.22
   Compiling unicode-segmentation v1.2.0
   Compiling libloading v0.4.0
   Compiling syntex_pos v0.58.1
   Compiling clang-sys v0.18.0
   Compiling kernel32-sys v0.2.2
   Compiling vec_map v0.8.0
error: failed to run custom build command for `kernel32-sys v0.2.2`
process didn't exit successfully: `C:\Users\camer\rs\octh_helloworld\target\debug\build\kernel32-sys-d715e52d58016295\b
uild-script-build` (exit code: 3221225781)
Build failed, waiting for other jobs to finish...
error: build failed

[ctaggart]

I tried again this past weekend to translate the simple example. I made progress. I'm able to compile with the rustup nightly-x86_64-pc-windows-gnu installed. That is until I try to create a new octave_value_list. I can't find the empty constructor. It looks like there are a few overloads in https://github.com/NexMirror/Octave/blob/master/libinterp/octave-value/ovl.h, but I can't find then in https://raw.githubusercontent.com/ctaggart/octh/master/src/lib.rs.

Current code for octh_helloworld\src\lib.rs:

#![allow(non_snake_case)]
#![allow(unused_variables)]

extern crate octh;

use std::ffi::CString;

// https://thefullsnack.com/en/string-ffi-rust.html

#[no_mangle]
pub unsafe extern "C"  fn Ghelloworld (shl: *const octh::root::octave::dynamic_library, relative: bool) -> *mut octh::root::octave_dld_function {

    let fname = CString::new("Fhelloworld").unwrap();
    let pfname = fname.as_ptr() as octh::root::octave_builtin_fcn;
    std::mem::forget(pfname);

    let name = CString::new("helloworld").unwrap();
    let pname = name.as_ptr() as *const octh::root::std::string;
    std::mem::forget(pname);

    let doc = CString::new("Hello World Help String").unwrap();
    let pdoc = doc.as_ptr() as *const octh::root::std::string;
    std::mem::forget(pdoc);

    let fcn = octh::root::octave_dld_function_create(pfname, shl, pname, pdoc);

//    if relative {
//        fcn.mark_relative();
//    }
    return fcn;
}    

pub unsafe extern "C"  fn Fhelloworld (args: *const octh::root::octave_value_list, nargout: i32) -> octh::root::octave_value_list {
    let out = octh::root::octave_value_list::new();
    return out;
}

Code for octh_helloworld\build.rs:

fn main () {
    println!("cargo:rustc-link-search={}", "C:\\Octave\\OCTAVE~1.1\\lib\\octave\\4.2.1");
    println!("cargo:rustc-link-lib={}", "octave");
    println!("cargo:rustc-link-lib={}", "octinterp");
}

Current error:

C:\Users\camer\rs\octh_helloworld>cargo build
   Compiling octh_helloworld v0.1.0 (file:///C:/Users/camer/rs/octh_helloworld)
error[E0061]: this function takes 1 parameter but 0 parameters were supplied
  --> src\lib.rs:38:15
   |
38 |     let out = octh::root::octave_value_list::new();
   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 1 parameter

[ctaggart]

I exposed an octave_value_list_create function via C++ in #20. The helloworld code is now here: https://github.com/ctaggart/octh_examples. It compiles, but does not link.

I think the current problem has something to do with libstdc++.a. I'm not sure if it is because it is found first in the rustup toolchain instead of Octave:

1. "-L" "C:\Users\camer\.rustup\toolchains\nightly-x86_64-pc-windows-gnu\lib\rustlib\x86_64-pc-windows-gnu\lib"
2. "-L" "C:\Octave\Octave-4.2.1\lib64\gcc\x86_64-w64-mingw32\4.9.4"

The full build log that is failing as well as the C++ one from Octave are in this gist:
https://gist.github.com/ctaggart/0a2676c24844890c161d6e5720a6b91f

[ctaggart]

I'm not receiving the pthread link errors anymore, but I'm still getting link errors:

          C:\Users\camer\AppData\Local\Temp\rustc.Hk7dvrSKrazQ\libocth-caff0ea2aef87dc7.rlib(octhc.o): In function `dim_vector::dim_vector()':
          C:/Octave/Octave-4.2.1/include/octave-4.2.1/octave/dim-vector.h:261: undefined reference to `dim_vector::nil_rep()'
          C:\Users\camer\AppData\Local\Temp\rustc.Hk7dvrSKrazQ\libocth-caff0ea2aef87dc7.rlib(octhc.o): In function `Array<std::string>::Array()':

          C:/Octave/Octave-4.2.1/include/octave-4.2.1/octave/Array.h:253: undefined reference to `Array<std::string>::nil_rep()'

          C:\Users\camer\AppData\Local\Temp\rustc.Hk7dvrSKrazQ\libocth-caff0ea2aef87dc7.rlib(octhc.o): In function `Array<octave_value>::Array()':

          C:/Octave/Octave-4.2.1/include/octave-4.2.1/octave/Array.h:253: undefined reference to `Array<octave_value>::nil_rep()'


          C:\Users\camer\AppData\Local\Temp\rustc.Hk7dvrSKrazQ\libocth-caff0ea2aef87dc7.rlib(octhc.o):octhc.cc:(.rdata$_ZTV5ArrayI12octave_valueE[_ZTV5ArrayI12octave_valueE]+0x20): 
undefined reference to `Array<octave_value>::resize_fill_value() const'

          C:\Users\camer\AppData\Local\Temp\rustc.Hk7dvrSKrazQ\libocth-caff0ea2aef87dc7.rlib(octhc.o):octhc.cc:(.rdata$_ZTV13string_vector[_ZTV13string_vector]+0x20): undefined 
reference to `Array<std::string>::resize_fill_value() const'

          C:\Users\camer\AppData\Local\Temp\rustc.Hk7dvrSKrazQ\libocth-caff0ea2aef87dc7.rlib(octhc.o):octhc.cc:(.rdata$_ZTV5ArrayISsE[_ZTV5ArrayISsE]+0x20): undefined reference to 
`Array<std::string>::resize_fill_value() const'


          collect2.exe: error: ld returned 1 exit status

The errors appears to be related to the octch.o, which is the C++ code using the gcc crate.

I was able make the ld linker be verbose when run from Octave:
build.m:

mkoctfile "-Wl,--verbose" helloworld.cc

build.ps1:

C:\Octave\Octave-4.2.1\bin\octave-cli.exe build.m > build.txt

build.txt

I'd like to have the same verbose ld output from Rust, but nothing I've tried has worked.

[fitzgen]

Where are Array<std::string>::resize_fill_value() const et al supposed to be defined? And are you sure they aren't inline functions, which would not have a symbol that can be linked against (in which case bindgen shouldn't be generating bindings to them, but older libclang doesn't give us a way to tell if a function is inlined or not)?

[ctaggart]

I got what I thought should be a helloworld compiling on Linux, but I get an unexpected Octave error when trying to load and run it. ctaggart/octh_examples#2