Allocated dict points to previously allocated dict.
Queue in allocated dict points to itself.
Hashtab in allocated dict points to inside itself.
Allocated dict is saved to gc_first_dict.
Not using enum{} because SIZE_MAX exceeds integer and I do not really like how
enum definition is described in C99:
1. Even though all values must fit into the chosen type (6.7.2.2, p 4) the type
to choose is still implementation-defined.
2. 6.4.4.3 explicitly states that “an identifier declared as an enumeration
constant has type `int`”. So it looks like “no matter what type was chosen
for enumeration, constants will be integers”. Yet the following simple
program:
#include <stdint.h>
#include <stdio.h>
#include <stddef.h>
enum { X=SIZE_MAX };
int main(int argc, char **argv)
{
printf("x:%zu m:%zu t:%zu v:%zu",
sizeof(X), sizeof(SIZE_MAX), sizeof(size_t), (size_t)X);
}
yields one of the following using different compilers:
- clang/gcc/pathcc: `x:8 m:8 t:8 v:18446744073709551615`
- pcc/tcc: `x:4 m:8 t:8 v:1844674407370955161`
If I remove the cast of X to size_t then pcc/tcc both yield `x:4 m:8 t:8
v:4294967295`, other compilers’ output does not change.
All compilers were called with `$compiler -std=c99 -xc -` (feeding program
from echo), except for `tcc` which has missing `-std=c99`. `pcc` seems to
ignore the argument though: it is perfectly fine with `-std=c1000`.
Calling cmd.exe in Windows follows a very different pattern from Vim.
The primary difference is that Vim does a nested call to cmd.exe, e.g.
the following call in Vim
system('echo a 2>&1')
spawns the following processes
"C:\Program Files (x86)\Vim\vim80\vimrun" -s C:\Windows\system32\cmd.exe /c (echo a 2^>^&1
^>C:\Users\dummy\AppData\Local\Temp\VIoC169.tmp 2^>^&1)
C:\Windows\system32\cmd.exe /c C:\Windows\system32\cmd.exe /c (echo a 2^>^&1
^>C:\Users\dummy\AppData\Local\Temp\VIo3C6C.tmp 2^>^&1)
C:\Windows\system32\cmd.exe /c (echo a 2>&1
>C:\Users\dummy\AppData\Local\Temp\VIo3C6C.tmp 2>&1)
The escaping with ^ is needed because cmd.exe calls itself and needs to
preserve the special metacharacters for the last call. However in nvim
no nested call is made, system('') spawns a single cmd.exe process.
Setting shellxescape to "" disables escaping with ^.
The previous default for shellxquote=( wrapped any command in
parenthesis, in Vim this is more meaningful due to the use of tempfiles
to store the output and redirection (also see &shellquote). There is
a slight benefit in having the default be empty because some expressions
that run in console will not run within parens e.g. due to unbalanced
double quotes
system('echo "a b')
Disable CommandLineToArgvW-standard quoting for cmd.exe.
libuv assumes spawned processes follow the convention expected by
CommandLineToArgvW(). But cmd.exe is non-conformant, so for cmd.exe:
- With system([]), the caller has full control (and responsibility) to
quote arguments correctly.
- With system(''), shell* options are used.
libuv quoting is disabled if argv[0] is:
- cmd.exe
- cmd
- $COMSPEC resolving to a path with filename cmd.exe
Closes#6329
References #6387
Should not really change anything, but code should be more efficient by using
more optimized libc functions (memchrsub is not libc, but it uses memchr) in
place of a cycle.
Reasoning is majorly the same: check whether lua has bug or API function has
bug, but on the other side: previous commit is checking whether similar bug when
using API via msgpack RPC, this commit is checking whether another API function
used via lua bindings triggers the same bug. Should additionally give a hint
about which lua code contains a bug.
On Windows, `mch_open_rw` is not actually doing what it claims. This
manifests as "E301: Oops, lost the swap file !!!" when filename is
changed with :file {name}.
Steps to reproduce (covered by test/functional/ex_cmds/file_spec.lua):
nvim -u NONE
:edit test
:file test2
E301 Oops, lost the swap file!!!
From libuv/src/win/fs.c:
void fs__open(uv_fs_t* req) {
...
attributes |= FILE_ATTRIBUTE_NORMAL;
if (flags & _O_CREAT) {
if (!((req->fs.info.mode & ~current_umask) & _S_IWRITE)) {
attributes |= FILE_ATTRIBUTE_READONLY;
}
}
Lua has too many pitfalls here:
- os.execute() requires shell-escaping
- os.execute() has breaking changes between Lua 5.1 and 5.2
- No native way in Lua to handle "readonly" etc. on Windows
> The option 'maxmem' ('mm') is used to set the maximum memory used for one
> buffer (in kilobytes). 'maxmemtot' is used to set the maximum memory used for
> all buffers (in kilobytes). The defaults depend on the system used. These
> are not hard limits, but tell Vim when to move text into a swap file. If you
> don't like Vim to swap to a file, set 'maxmem' and 'maxmemtot' to a very large
> value. The swap file will then only be used for recovery. If you don't want
> a swap file at all, set 'updatecount' to 0, or use the "-n" argument when
> starting Vim.
On today's systems these values are huge (4GB in my machine with 8GB of RAM
since it's set as half the available memory by default) so the limits are
never reached in practice, but Vim wastes a lot of time checking if the limit
was reached.
If the limit is reached Vim starts saving pieces of the swap file that were in
memory to the disk. Said in a different way: Vim implements its own memory
swapping mechanism. This is unnecessary and inefficient since the operating
system already virtualized the memory and will swap to the disk if programs
start using too much memory.
This change does...
1. Reduce the number of config options and need for documentation.
2. Make the code more efficient as we don't have to keep track of memory usage
nor check if the memory limits were reached to start swapping to disk every
time we need memory for buffers.
3. Simplify the code. Once `memfile.c` is simple enough it could be replaced by
actual operating system memory mapping (`mmap`, `MemoryViewOfFile`...).
This change does not prevent Vim to recover changes from swap files since the
swapping code is never triggered with the huge limits set by default.
