ac055d677a
Closes #4370 Explication: In the backtrace in #4370, we see that `buf_write()` was called with non-NULL `fname` and `sfname` arguments, but they've since _become_ NULL. #7 0x00000000004de09d in buf_write (buf=0x1dee040, fname=0x0, fname@entry=0x1e985b0 "/home/sean/src/github.com/snczl/virta/pkg/meld/segment.go", sfname=0x0, sfname@entry=0x1ddfa60 "segment.go", start=1, end=72, eap=eap@entry=0x7ffc6b032e60, append=0, forceit=0, reset_changed=1, filtering=0) at /home/travis/build/neovim/bot-ci/build/neovim/src/nvim/fileio.c:2576 This is most likely due to the code that restores those values from `buf`, which happens just before the fatal call to `os_fileinfo` ```c /* * The autocommands may have changed the name of the buffer, which may * be kept in fname, ffname and sfname. */ if (buf_ffname) ffname = buf->b_ffname; if (buf_sfname) sfname = buf->b_sfname; if (buf_fname_f) fname = buf->b_ffname; if (buf_fname_s) fname = buf->b_sfname; ``` It's worth noting that at this point `ffname` is still non-NULL, so it _could_ be used. However, our current code is purely more strict than Vim in this area, which has caused us problems before (e.g., `getdigits()`). The commentary for `struct file_buffer` clearly indicate that all of `b_ffname`, `b_sfname`, and `b_fname` may be NULL: ```c /* * b_ffname has the full path of the file (NULL for no name). * b_sfname is the name as the user typed it (or NULL). * b_fname is the same as b_sfname, unless ":cd" has been done, * then it is the same as b_ffname (NULL for no name). */ char_u *b_ffname; /* full path file name */ char_u *b_sfname; /* short file name */ char_u *b_fname; /* current file name */ ``` Vim directly calls `stat(2)` which, although it is annotated to tell the compiler that the path argument is non-NULL, does handle a NULL pointer by returning a `-1` value and setting `errno` to `EFAULT`. This satisfies Vim's check, since it treats any `-1` return from `stat(2)` to mean the file doesn't exist (at least in this code path). Note that Vim's mch_stat() implementations on win32 and solaris clearly cannot accept NULL `name`. But the codepaths that call mch_stat will NULL `name` tend to be unix-only (eg: u_read_undo)!
Tests
Tests are run by /cmake/RunTests.cmake file, using busted.
For some failures, .nvimlog (or $NVIM_LOG_FILE) may provide insight.
Directory structure
Directories with tests: /test/benchmark for benchmarks, /test/functional for
functional tests, /test/unit for unit tests. /test/config contains *.in
files (currently a single one) which are transformed into *.lua files using
configure_file CMake command: this is for acessing CMake variables in lua
tests. /test/includes contains include files for use by luajit ffi.cdef
C definitions parser: normally used to make macros not accessible via this
mechanism accessible the other way.
Files /test/*/preload.lua contain modules which will be preloaded by busted,
via --helper option. /test/**/helpers.lua contain various “library”
functions, (intended to be) used by a number of tests and not just a single one.
/test/*/**/*_spec.lua are files containing actual tests. Files that do not end
with a _spec.lua are libraries like /test/**/helpers.lua, except that they
have some common topic.
Tests inside /test/unit and /test/functional are normally divided into
groups by the semantic component they are testing.
Environment variables
Test behaviour is affected by environment variables. Currently supported (Functional, Unit, Benchmarks) (when Defined; when set to 1; when defined, treated as Integer; when defined, treated as String; when defined, treated as Number; !must be defined to function properly):
GDB (F) (D): makes nvim instances to be run under gdbserver. It will be
accessible on localhost:7777: use gdb build/bin/nvim, type target remote :7777 inside.
GDBSERVER_PORT (F) (I): overrides port used for GDB.
VALGRIND (F) (D): makes nvim instances to be run under valgrind. Log files
are named valgrind-%p.log in this case. Note that non-empty valgrind log may
fail tests. Valgrind arguments may be seen in /test/functional/helpers.lua.
May be used in conjunction with GDB.
VALGRIND_LOG (F) (S): overrides valgrind log file name used for VALGRIND.
TEST_SKIP_FRAGILE (F) (D): makes test suite skip some fragile tests.
NVIM_PROG, NVIM_PRG (F) (S): override path to Neovim executable (default to
build/bin/nvim).
CC (U) (S): specifies which C compiler to use to preprocess files. Currently
only compilers with gcc-compatible arguments are supported.
NVIM_TEST_MAIN_CDEFS (U) (1): makes ffi.cdef run in main process. This
raises a possibility of bugs due to conflicts in header definitions, despite the
counters, but greatly speeds up unit tests by not requiring ffi.cdef to do
parsing of big strings with C definitions.
NVIM_TEST_PRINT_I (U) (1): makes cimport print preprocessed, but not yet
filtered through formatc headers. Used to debug formatc. Printing is done
with the line numbers.
NVIM_TEST_PRINT_CDEF (U) (1): makes cimport print final lines which will be
then passed to ffi.cdef. Used to debug errors ffi.cdef happens to throw
sometimes.
NVIM_TEST_PRINT_SYSCALLS (U) (1): makes it print to stderr when syscall
wrappers are called and what they returned. Used to debug code which makes unit
tests be executed in separate processes.
NVIM_TEST_RUN_FAILING_TESTS (U) (1): makes itp run tests which are known to
fail (marked by setting third argument to true).
LOG_DIR (FU) (S!): specifies where to seek for valgrind and ASAN log files.
NVIM_TEST_CORE_* (FU) (S): a set of environment variables which specify where
to search for core files. Are supposed to be defined all at once.
NVIM_TEST_CORE_GLOB_DIRECTORY (FU) (S): directory where core files are
located. May be .. This directory is then recursively searched for core files.
Note: this variable must be defined for any of the following to have any effect.
NVIM_TEST_CORE_GLOB_RE (FU) (S): regular expression which must be matched by
core files. E.g. /core[^/]*$. May be absent, in which case any file is
considered to be matched.
NVIM_TEST_CORE_EXC_RE (FU) (S): regular expression which excludes certain
directories from searching for core files inside. E.g. use ^/%.deps$ to not
search inside /.deps. If absent, nothing is excluded.
NVIM_TEST_CORE_DB_CMD (FU) (S): command to get backtrace out of the debugger.
E.g. gdb -n -batch -ex "thread apply all bt full" "$_NVIM_TEST_APP" -c "$_NVIM_TEST_CORE". Defaults to the example command. This debug command may use
environment variables _NVIM_TEST_APP (path to application which is being
debugged: normally either nvim or luajit) and _NVIM_TEST_CORE (core file to
get backtrace from).
NVIM_TEST_CORE_RANDOM_SKIP (FU) (D): makes check_cores not check cores after
approximately 90% of the tests. Should be used when finding cores is too hard
for some reason. Normally (on OS X or when NVIM_TEST_CORE_GLOB_DIRECTORY is
defined and this variable is not) cores are checked for after each test.
NVIM_TEST_RUN_TESTTEST (U) (1): allows running test/unit/testtest_spec.lua
used to check how testing infrastructure works.
NVIM_TEST_TRACE_LEVEL (U) (N): specifies unit tests tracing level: 0
disables tracing (the fastest, but you get no data if tests crash and there was
no core dump generated), 1 or empty/undefined leaves only C function cals and
returns in the trace (faster then recording everything), 2 records all
function calls, returns and lua source lines exuecuted.