view src/testdir/test_xxd.vim @ 32936:c517845bd10e v9.0.1776

patch 9.0.1776: No support for stable Python 3 ABI Commit: https://github.com/vim/vim/commit/c13b3d1350b60b94fe87f0761ea31c0e7fb6ebf3 Author: Yee Cheng Chin <ychin.git@gmail.com> Date: Sun Aug 20 21:18:38 2023 +0200 patch 9.0.1776: No support for stable Python 3 ABI Problem: No support for stable Python 3 ABI Solution: Support Python 3 stable ABI Commits: 1) Support Python 3 stable ABI to allow mixed version interoperatbility Vim currently supports embedding Python for use with plugins, and the "dynamic" linking option allows the user to specify a locally installed version of Python by setting `pythonthreedll`. However, one caveat is that the Python 3 libs are not binary compatible across minor versions, and mixing versions can potentially be dangerous (e.g. let's say Vim was linked against the Python 3.10 SDK, but the user sets `pythonthreedll` to a 3.11 lib). Usually, nothing bad happens, but in theory this could lead to crashes, memory corruption, and other unpredictable behaviors. It's also difficult for the user to tell something is wrong because Vim has no way of reporting what Python 3 version Vim was linked with. For Vim installed via a package manager, this usually isn't an issue because all the dependencies would already be figured out. For prebuilt Vim binaries like MacVim (my motivation for working on this), AppImage, and Win32 installer this could potentially be an issue as usually a single binary is distributed. This is more tricky when a new Python version is released, as there's a chicken-and-egg issue with deciding what Python version to build against and hard to keep in sync when a new Python version just drops and we have a mix of users of different Python versions, and a user just blindly upgrading to a new Python could lead to bad interactions with Vim. Python 3 does have a solution for this problem: stable ABI / limited API (see https://docs.python.org/3/c-api/stable.html). The C SDK limits the API to a set of functions that are promised to be stable across versions. This pull request adds an ifdef config that allows us to turn it on when building Vim. Vim binaries built with this option should be safe to freely link with any Python 3 libraies without having the constraint of having to use the same minor version. Note: Python 2 has no such concept and this doesn't change how Python 2 integration works (not that there is going to be a new version of Python 2 that would cause compatibility issues in the future anyway). --- Technical details: ====== The stable ABI can be accessed when we compile with the Python 3 limited API (by defining `Py_LIMITED_API`). The Python 3 code (in `if_python3.c` and `if_py_both.h`) would now handle this and switch to limited API mode. Without it set, Vim will still use the full API as before so this is an opt-in change. The main difference is that `PyType_Object` is now an opaque struct that we can't directly create "static types" out of, and we have to create type objects as "heap types" instead. This is because the struct is not stable and changes from version to version (e.g. 3.8 added a `tp_vectorcall` field to it). I had to change all the types to be allocated on the heap instead with just a pointer to them. Other functions are also simply missing in limited API, or they are introduced too late (e.g. `PyUnicode_AsUTF8AndSize` in 3.10) to it that we need some other ways to do the same thing, so I had to abstract a few things into macros, and sometimes re-implement functions like `PyObject_NEW`. One caveat is that in limited API, `OutputType` (used for replacing `sys.stdout`) no longer inherits from `PyStdPrinter_Type` which I don't think has any real issue other than minor differences in how they convert to a string and missing a couple functions like `mode()` and `fileno()`. Also fixed an existing bug where `tp_basicsize` was set incorrectly for `BufferObject`, `TabListObject, `WinListObject`. Technically, there could be a small performance drop, there is a little more indirection with accessing type objects, and some APIs like `PyUnicode_AsUTF8AndSize` are missing, but in practice I didn't see any difference, and any well-written Python plugin should try to avoid excessing callbacks to the `vim` module in Python anyway. I only tested limited API mode down to Python 3.7, which seemes to compile and work fine. I haven't tried earlier Python versions. 2) Fix PyIter_Check on older Python vers / type##Ptr unused warning For PyIter_Check, older versions exposed them as either macros (used in full API), or a function (for use in limited API). A previous change exposed PyIter_Check to the dynamic build because Python just moved it to function-only in 3.10 anyway. Because of that, just make sure we always grab the function in dynamic builds in earlier versions since that's what Python eventually did anyway. 3) Move Py_LIMITED_API define to configure script Can now use --with-python-stable-abi flag to customize what stable ABI version to target. Can also use an env var to do so as well. 4) Show +python/dyn-stable in :version, and allow has() feature query Not sure if the "/dyn-stable" suffix would break things, or whether we should do it another way. Or just don't show it in version and rely on has() feature checking. 5) Documentation first draft. Still need to implement v:python3_version 6) Fix PyIter_Check build breaks when compiling against Python 3.8 7) Add CI coverage stable ABI on Linux/Windows / make configurable on Windows This adds configurable options for Windows make files (both MinGW and MSVC). CI will also now exercise both traditional full API and stable ABI for Linux and Windows in the matrix for coverage. Also added a "dynamic" option to Linux matrix as a drive-by change to make other scripting languages like Ruby / Perl testable under both static and dynamic builds. 8) Fix inaccuracy in Windows docs Python's own docs are confusing but you don't actually want to use `python3.dll` for the dynamic linkage. 9) Add generated autoconf file 10) Add v:python3_version support This variable indicates the version of Python3 that Vim was built against (PY_VERSION_HEX), and will be useful to check whether the Python library you are loading in dynamically actually fits it. When built with stable ABI, it will be the limited ABI version instead (`Py_LIMITED_API`), which indicates the minimum version of Python 3 the user should have, rather than the exact match. When stable ABI is used, we won't be exposing PY_VERSION_HEX in this var because it just doesn't seem necessary to do so (the whole point of stable ABI is the promise that it will work across versions), and I don't want to confuse the user with too many variables. Also, cleaned up some documentation, and added help tags. 11) Fix Python 3.7 compat issues Fix a couple issues when using limited API < 3.8 - Crash on exit: In Python 3.7, if a heap-allocated type is destroyed before all instances are, it would cause a crash later. This happens when we destroyed `OptionsType` before calling `Py_Finalize` when using the limited API. To make it worse, later versions changed the semantics and now each instance has a strong reference to its own type and the recommendation has changed to have each instance de-ref its own type and have its type in GC traversal. To avoid dealing with these cross-version variations, we just don't free the heap type. They are static types in non-limited-API anyway and are designed to last through the entirety of the app, and we also don't restart the Python runtime and therefore do not need it to have absolutely 0 leaks. See: - https://docs.python.org/3/whatsnew/3.8.html#changes-in-the-c-api - https://docs.python.org/3/whatsnew/3.9.html#changes-in-the-c-api - PyIter_Check: This function is not provided in limited APIs older than 3.8. Previously I was trying to mock it out using manual PyType_GetSlot() but it was brittle and also does not actually work properly for static types (it will generate a Python error). Just return false. It does mean using limited API < 3.8 is not recommended as you lose the functionality to handle iterators, but from playing with plugins I couldn't find it to be an issue. - Fix loading of PyIter_Check so it will be done when limited API < 3.8. Otherwise loading a 3.7 Python lib will fail even if limited API was specified to use it. 12) Make sure to only load `PyUnicode_AsUTF8AndSize` in needed in limited API We don't use this function unless limited API >= 3.10, but we were loading it regardless. Usually it's ok in Unix-like systems where Python just has a single lib that we load from, but in Windows where there is a separate python3.dll this would not work as the symbol would not have been exposed in this more limited DLL file. This makes it much clearer under what condition is this function needed. closes: #12032 Signed-off-by: Christian Brabandt <cb@256bit.org> Co-authored-by: Yee Cheng Chin <ychin.git@gmail.com>
author Christian Brabandt <cb@256bit.org>
date Sun, 20 Aug 2023 21:30:04 +0200
parents 5a1113ece237
children 79b2eb83f2df
line wrap: on
line source

" Test for the xxd command

if empty($XXD) && executable('..\xxd\xxd.exe')
  let s:xxd_cmd = '..\xxd\xxd.exe'
elseif empty($XXD) || !executable($XXD)
  throw 'Skipped: xxd program missing'
else
  let s:xxd_cmd = $XXD
endif

func PrepareBuffer(lines)
  new
  call append(0, a:lines)
  $d
endfunc

func s:Mess(counter)
  return printf("Failed xxd test %d:", a:counter)
endfunc

func Test_xxd()
  call PrepareBuffer(range(1,30))
  set ff=unix
  w! XXDfile

  " Test 1: simple, filter the result through xxd
  let s:test = 1
  exe '%!' . s:xxd_cmd . ' %'
  let expected = [
        \ '00000000: 310a 320a 330a 340a 350a 360a 370a 380a  1.2.3.4.5.6.7.8.',
        \ '00000010: 390a 3130 0a31 310a 3132 0a31 330a 3134  9.10.11.12.13.14',
        \ '00000020: 0a31 350a 3136 0a31 370a 3138 0a31 390a  .15.16.17.18.19.',
        \ '00000030: 3230 0a32 310a 3232 0a32 330a 3234 0a32  20.21.22.23.24.2',
        \ '00000040: 350a 3236 0a32 370a 3238 0a32 390a 3330  5.26.27.28.29.30',
        \ '00000050: 0a                                       .']
  call assert_equal(expected, getline(1,'$'), s:Mess(s:test))

  " Test 2: reverse the result
  let s:test += 1
  exe '%!' . s:xxd_cmd . ' -r'
  call assert_equal(map(range(1,30), {v,c -> string(c)}), getline(1,'$'), s:Mess(s:test))

  " Test 3: Skip the first 0x30 bytes
  let s:test += 1
  for arg in ['-s 0x30', '-s0x30', '-s+0x30', '-skip 0x030', '-seek 0x30', '-seek +0x30 --']
    exe '%!' . s:xxd_cmd . ' ' . arg . ' %'
    call assert_equal(expected[3:], getline(1,'$'), s:Mess(s:test))
  endfor

  " Test 4: Skip the first 30 bytes
  let s:test += 1
  for arg in ['-s -0x31', '-s-0x31']
    exe '%!' . s:xxd_cmd . ' ' . arg . ' %'
    call assert_equal(expected[2:], getline(1,'$'), s:Mess(s:test))
  endfor

  " The following tests use the xxd man page.
  " For these tests to pass, the fileformat must be "unix".
  let man_copy = 'Xxd.1'
  let man_page = '../../runtime/doc/xxd.1'
  if has('win32') && !filereadable(man_page)
    let man_page = '../../doc/xxd.1'
  endif
  %d
  exe '0r ' man_page '| set ff=unix | $d | w' man_copy '| bwipe!' man_copy

  " Test 5: Print 120 bytes as continuous hexdump with 20 octets per line
  let s:test += 1
  %d
  exe '0r! ' . s:xxd_cmd . ' -l 120 -ps -c20 ' . man_copy
  $d
  let expected = [
      \ '2e54482058584420312022417567757374203139',
      \ '39362220224d616e75616c207061676520666f72',
      \ '20787864220a2e5c220a2e5c222032317374204d',
      \ '617920313939360a2e5c22204d616e2070616765',
      \ '20617574686f723a0a2e5c2220202020546f6e79',
      \ '204e7567656e74203c746f6e79407363746e7567']
  call assert_equal(expected, getline(1,'$'), s:Mess(s:test))

  " Test 6: Print the date from xxd.1
  let s:test += 1
  for arg in ['-l 13', '-l13', '-len 13']
    %d
    exe '0r! ' . s:xxd_cmd . ' -s 0x36 ' . arg . ' -cols 13 ' . man_copy
    $d
    call assert_equal('00000036: 3231 7374 204d 6179 2031 3939 36  21st May 1996', getline(1), s:Mess(s:test))
  endfor

  " Cleanup after tests 5 and 6
  call delete(man_copy)

  " Test 7: Print C include
  let s:test += 1
  call writefile(['TESTabcd09'], 'XXDfile')
  %d
  exe '0r! ' . s:xxd_cmd . ' -i XXDfile'
  $d
  let expected =<< trim [CODE]
    unsigned char XXDfile[] = {
      0x54, 0x45, 0x53, 0x54, 0x61, 0x62, 0x63, 0x64, 0x30, 0x39, 0x0a
    };
    unsigned int XXDfile_len = 11;
  [CODE]

  call assert_equal(expected, getline(1,'$'), s:Mess(s:test))

  " Test 8: Print C include capitalized
  let s:test += 1
  for arg in ['-C', '-capitalize']
    call writefile(['TESTabcd09'], 'XXDfile')
    %d
    exe '0r! ' . s:xxd_cmd . ' -i ' . arg . ' XXDfile'
    $d
    let expected =<< trim [CODE]
      unsigned char XXDFILE[] = {
        0x54, 0x45, 0x53, 0x54, 0x61, 0x62, 0x63, 0x64, 0x30, 0x39, 0x0a
      };
      unsigned int XXDFILE_LEN = 11;
    [CODE]
    call assert_equal(expected, getline(1,'$'), s:Mess(s:test))
  endfor

  " Test 9: Create a file with containing a single 'A'
  let s:test += 1
  call delete('XXDfile')
  bwipe! XXDfile
  if has('unix')
    call system('echo "010000: 41"|' . s:xxd_cmd . ' -r -s -0x10000 > XXDfile')
  else
    call writefile(['010000: 41'], 'Xinput')
    silent exe '!' . s:xxd_cmd . ' -r -s -0x10000 < Xinput > XXDfile'
    call delete('Xinput')
  endif
  call PrepareBuffer(readfile('XXDfile')[0])
  call assert_equal('A', getline(1), s:Mess(s:test))
  call delete('XXDfile')

  " Test 10: group with 4 octets
  let s:test += 1
  for arg in ['-g 4', '-group 4', '-g4']
    call writefile(['TESTabcd09'], 'XXDfile')
    %d
    exe '0r! ' . s:xxd_cmd . ' ' . arg . ' XXDfile'
    $d
    let expected = ['00000000: 54455354 61626364 30390a             TESTabcd09.']
    call assert_equal(expected, getline(1,'$'), s:Mess(s:test))
    call delete('XXDfile')
  endfor

  " Test 11: reverse with CR, hex upper, Postscript style with a TAB
  let s:test += 1
  call writefile([" 54455354\t610B6364 30390A             TESTa\0x0bcd09.\r"], 'Xinput')
  silent exe '!' . s:xxd_cmd . ' -r -p < Xinput > XXDfile'
  let blob = readfile('XXDfile', 'B')
  call assert_equal(0z54455354.610B6364.30390A, blob)
  call delete('Xinput')
  call delete('XXDfile')

  " Test 12: reverse with seek
  let s:test += 1
  call writefile(["00000000: 54455354\t610B6364 30390A             TESTa\0x0bcd09.\r"], 'Xinput')
  silent exe '!' . s:xxd_cmd . ' -r -seek 5 < Xinput > XXDfile'
  let blob = readfile('XXDfile', 'B')
  call assert_equal(0z0000000000.54455354.610B6364.30390A, blob)
  call delete('Xinput')
  call delete('XXDfile')

  " Test 13: simple, decimal offset
  call PrepareBuffer(range(1,30))
  set ff=unix
  w! XXDfile
  let s:test += 1
  exe '%!' . s:xxd_cmd . ' -d %'
  let expected = [
        \ '00000000: 310a 320a 330a 340a 350a 360a 370a 380a  1.2.3.4.5.6.7.8.',
        \ '00000016: 390a 3130 0a31 310a 3132 0a31 330a 3134  9.10.11.12.13.14',
        \ '00000032: 0a31 350a 3136 0a31 370a 3138 0a31 390a  .15.16.17.18.19.',
        \ '00000048: 3230 0a32 310a 3232 0a32 330a 3234 0a32  20.21.22.23.24.2',
        \ '00000064: 350a 3236 0a32 370a 3238 0a32 390a 3330  5.26.27.28.29.30',
        \ '00000080: 0a                                       .']
  call assert_equal(expected, getline(1,'$'), s:Mess(s:test))

  " Test 14: grouping with -d
  let s:test += 1
  let expected = [
        \ '00000000: 310a320a 330a340a 350a360a 370a380a  1.2.3.4.5.6.7.8.',
        \ '00000016: 390a3130 0a31310a 31320a31 330a3134  9.10.11.12.13.14',
        \ '00000032: 0a31350a 31360a31 370a3138 0a31390a  .15.16.17.18.19.',
        \ '00000048: 32300a32 310a3232 0a32330a 32340a32  20.21.22.23.24.2',
        \ '00000064: 350a3236 0a32370a 32380a32 390a3330  5.26.27.28.29.30',
        \ '00000080: 0a                                   .']
  for arg in ['-g 4', '-group 4', '-g4']
    exe '%!' . s:xxd_cmd . ' ' . arg . ' -d %'
    call assert_equal(expected, getline(1,'$'), s:Mess(s:test))
  endfor

  " Test 15: cols with decimal offset: -c 21 -d
  let s:test += 1
  let expected = [
        \ '00000000: 310a 320a 330a 340a 350a 360a 370a 380a 390a 3130 0a  1.2.3.4.5.6.7.8.9.10.',
        \ '00000021: 3131 0a31 320a 3133 0a31 340a 3135 0a31 360a 3137 0a  11.12.13.14.15.16.17.',
        \ '00000042: 3138 0a31 390a 3230 0a32 310a 3232 0a32 330a 3234 0a  18.19.20.21.22.23.24.',
        \ '00000063: 3235 0a32 360a 3237 0a32 380a 3239 0a33 300a          25.26.27.28.29.30.']
  exe '%!' . s:xxd_cmd . ' -c 21 -d %'
  call assert_equal(expected, getline(1,'$'), s:Mess(s:test))

  " Test 16: -o -offset
  let s:test += 1
  let expected = [
        \ '0000000f: 310a 320a 330a 340a 350a 360a 370a 380a  1.2.3.4.5.6.7.8.',
        \ '0000001f: 390a 3130 0a31 310a 3132 0a31 330a 3134  9.10.11.12.13.14',
        \ '0000002f: 0a31 350a 3136 0a31 370a 3138 0a31 390a  .15.16.17.18.19.',
        \ '0000003f: 3230 0a32 310a 3232 0a32 330a 3234 0a32  20.21.22.23.24.2',
        \ '0000004f: 350a 3236 0a32 370a 3238 0a32 390a 3330  5.26.27.28.29.30',
        \ '0000005f: 0a                                       .']
  for arg in ['-o 15', '-offset 15', '-o15']
    exe '%!' . s:xxd_cmd . ' ' . arg . ' %'
    call assert_equal(expected, getline(1,'$'), s:Mess(s:test))
  endfor

  " Test 17: Print C include with custom variable name
  let s:test += 1
  call writefile(['TESTabcd09'], 'XXDfile')
  for arg in ['-nvarName', '-n varName', '-name varName']
    %d
    exe '0r! ' . s:xxd_cmd . ' -i ' . arg . ' XXDfile'
    $d
    let expected =<< trim [CODE]
      unsigned char varName[] = {
        0x54, 0x45, 0x53, 0x54, 0x61, 0x62, 0x63, 0x64, 0x30, 0x39, 0x0a
      };
      unsigned int varName_len = 11;
    [CODE]

    call assert_equal(expected, getline(1,'$'), s:Mess(s:test))
  endfor

  " using "-n name" reading from stdin
  %d
  exe '0r! ' . s:xxd_cmd . ' -i < XXDfile -n StdIn'
  $d
  let expected =<< trim [CODE]
    unsigned char StdIn[] = {
      0x54, 0x45, 0x53, 0x54, 0x61, 0x62, 0x63, 0x64, 0x30, 0x39, 0x0a
    };
    unsigned int StdIn_len = 11;
  [CODE]
  call assert_equal(expected, getline(1,'$'), s:Mess(s:test))


  " Test 18: Print C include: custom variable names can be capitalized
  let s:test += 1
  for arg in ['-C', '-capitalize']
    call writefile(['TESTabcd09'], 'XXDfile')
    %d
    exe '0r! ' . s:xxd_cmd . ' -i ' . arg . ' -n varName XXDfile'
    $d
    let expected =<< trim [CODE]
      unsigned char VARNAME[] = {
        0x54, 0x45, 0x53, 0x54, 0x61, 0x62, 0x63, 0x64, 0x30, 0x39, 0x0a
      };
      unsigned int VARNAME_LEN = 11;
    [CODE]
    call assert_equal(expected, getline(1,'$'), s:Mess(s:test))
  endfor


  %d
  bwipe!
  call delete('XXDfile')
endfunc

func Test_xxd_patch()
  let cmd1 = 'silent !' .. s:xxd_cmd .. ' -r Xxxdin Xxxdfile'
  let cmd2 = 'silent !' .. s:xxd_cmd .. ' -g1 Xxxdfile > Xxxdout'
  call writefile(["2: 41 41", "8: 42 42"], 'Xxxdin', 'D')
  call writefile(['::::::::'], 'Xxxdfile', 'D')
  exe cmd1
  exe cmd2
  call assert_equal(['00000000: 3a 3a 41 41 3a 3a 3a 3a 42 42                    ::AA::::BB'], readfile('Xxxdout'))

  call writefile(["2: 43 43 ", "8: 44 44"], 'Xxxdin')
  exe cmd1
  exe cmd2
  call assert_equal(['00000000: 3a 3a 43 43 3a 3a 3a 3a 44 44                    ::CC::::DD'], readfile('Xxxdout'))

  call writefile(["2: 45 45  ", "8: 46 46"], 'Xxxdin')
  exe cmd1
  exe cmd2
  call assert_equal(['00000000: 3a 3a 45 45 3a 3a 3a 3a 46 46                    ::EE::::FF'], readfile('Xxxdout'))

  call writefile(["2: 41 41", "08: 42 42"], 'Xxxdin')
  call writefile(['::::::::'], 'Xxxdfile')
  exe cmd1
  exe cmd2
  call assert_equal(['00000000: 3a 3a 41 41 3a 3a 3a 3a 42 42                    ::AA::::BB'], readfile('Xxxdout'))

  call writefile(["2: 43 43 ", "09: 44 44"], 'Xxxdin')
  exe cmd1
  exe cmd2
  call assert_equal(['00000000: 3a 3a 43 43 3a 3a 3a 3a 42 44 44                 ::CC::::BDD'], readfile('Xxxdout'))

  call writefile(["2: 45 45  ", "0a: 46 46"], 'Xxxdin')
  exe cmd1
  exe cmd2
  call assert_equal(['00000000: 3a 3a 45 45 3a 3a 3a 3a 42 44 46 46              ::EE::::BDFF'], readfile('Xxxdout'))

  call delete('Xxxdout')
endfunc

" Various ways with wrong arguments that trigger the usage output.
func Test_xxd_usage()
  for arg in ['-h', '-c', '-g', '-o', '-s', '-l', '-X', 'one two three']
    new
    exe 'r! ' . s:xxd_cmd . ' ' . arg
    call assert_match("Usage:", join(getline(1, 3)))
    bwipe!
  endfor
endfunc

func Test_xxd_ignore_garbage()
  new
  exe 'r! printf "\n\r xxxx 0: 42 42" | ' . s:xxd_cmd . ' -r'
  call assert_match('BB', join(getline(1, 3)))
  bwipe!
endfunc

func Test_xxd_bit_dump()
  new
  exe 'r! printf "123456" | ' . s:xxd_cmd . ' -b1'
  call assert_match('00000000: 00110001 00110010 00110011 00110100 00110101 00110110  123456', join(getline(1, 3)))
  bwipe!
endfunc

func Test_xxd_version()
  new
  exe 'r! ' . s:xxd_cmd . ' -v'
  call assert_match('xxd 20\d\d-\d\d-\d\d by Juergen Weigert et al\.', join(getline(1, 3)))
  bwipe!
endfunc

" number of columns must be non-negative
func Test_xxd_min_cols()
  for cols in ['-c-1', '-c -1', '-cols -1']
    for fmt in ['', '-b', '-e', '-i', '-p', ]
      new
      exe 'r! printf "ignored" | ' . s:xxd_cmd . ' ' . cols . ' ' . fmt
      call assert_match("invalid number of columns", join(getline(1, '$')))
      bwipe!
    endfor
  endfor
endfunc

" some hex formats limit columns to 256 (a #define in xxd.c)
func Test_xxd_max_cols()
  for cols in ['-c257', '-c 257', '-cols 257']
    for fmt in ['', '-b', '-e' ]
      new
      exe 'r! printf "ignored" | ' . s:xxd_cmd . ' ' . cols . ' ' . fmt
      call assert_match("invalid number of columns", join(getline(1, '$')))
      bwipe!
    endfor
  endfor
endfunc

" -c0 selects the format specific default column value, as if no -c was given
" except for -ps, where it disables extra newlines
func Test_xxd_c0_is_def_cols()
  call writefile(["abcdefghijklmnopqrstuvwxyz0123456789"], 'Xxdin', 'D')
  for cols in ['-c0', '-c 0', '-cols 0']
    for fmt in ['', '-b', '-e', '-i']
      exe 'r! ' . s:xxd_cmd . ' ' . fmt ' Xxdin > Xxdout1'
      exe 'r! ' . s:xxd_cmd . ' ' . cols . ' ' . fmt ' Xxdin > Xxdout2'
      call assert_equalfile('Xxdout1', 'Xxdout2')
    endfor
  endfor
  call delete('Xxdout1')
  call delete('Xxdout2')
endfunc

" all output in a single line for -c0 -ps
func Test_xxd_plain_one_line()
  call writefile([
        \ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789",
        \ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789",
        \ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789",
        \ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789",
        \ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789",
        \ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"],
        \ 'Xxdin', 'D')
  for cols in ['-c0', '-c 0', '-cols 0']
    exe 'r! ' . s:xxd_cmd . ' -ps ' . cols ' Xxdin'
    " output seems to start in line 2
    let out = join(getline(2, '$'))
    bwipe!
    " newlines in xxd output result in spaces in the string variable out
    call assert_notmatch(" ", out)
    " xxd output must be non-empty and comprise only lower case hex digits
    call assert_match("^[0-9a-f][0-9a-f]*$", out)
  endfor
endfunc

func Test_xxd_little_endian_with_cols()
  enew!
  call writefile(["ABCDEF"], 'Xxdin', 'D')
  exe 'r! ' .. s:xxd_cmd .. ' -e -c6 ' .. ' Xxdin'
  call assert_equal('00000000: 44434241     4645   ABCDEF', getline(2))

  enew!
  call writefile(["ABCDEFGHI"], 'Xxdin', 'D')
  exe 'r! ' .. s:xxd_cmd .. ' -e -c9 ' .. ' Xxdin'
  call assert_equal('00000000: 44434241 48474645       49   ABCDEFGHI', getline(2))

  bwipe!
endfunc

" vim: shiftwidth=2 sts=2 expandtab