Corrects a slicing mistake in the `std/varints` implementation which
caused it to fail when writing large numbers into buffers smaller than
10..13-bytes, now 9-byte buffers are sufficient as the documentation
states.
fixes#10440, fixes#13871, fixes#14665, fixes#19672, fixes#23677
The false positive in #23677 was caused by behavior in
`implicitlyDiscardable` where only the last node of `if`/`case`/`try`
etc expressions were considered, as in the final node of the final
branch (in this case `else`). To fix this we use the same iteration in
`implicitlyDiscardable` that we use in `endsInNoReturn`, with the
difference that for an `if`/`case`/`try` statement to be implicitly
discardable, all of its branches must be implicitly discardable.
`noreturn` calls are also considered implicitly discardable for this
reason, otherwise stuff like `if true: discardableCall() else: error()`
doesn't compile.
However `endsInNoReturn` also had bugs, one where `finally` was
considered in noreturn checking when it shouldn't, another where only
`nkIfStmt` was checked and not `nkIfExpr`, and the node given for the
error message was bad. So `endsInNoReturn` now skips over
`skipForDiscardable` which no longer contains
`nkIfStmt`/`nkCaseStmt`/`nkTryStmt`, stores the first encountered
returning node in a var parameter for the error message, and handles
`finally` and `nkIfExpr`.
Fixing #23677 already broke a line in `syncio` so some package code
might be affected.
Because `isGitRepo()` call requires `/bin/sh` it will always fail when
building Nim in a Nix build sandbox, and the check doesn't even make
sense if Nix already provides Nimble source code.
Since for Nimble `allowBundled` is set to `true` this effectlvely does
not change behavior for normal builds, but does avoid ugly hacks when
building in Nix which lacks `/bin/sh` and fails to call `git`.
Reference:
*
https://github.com/status-im/nimbus-eth2/pull/6180#discussion_r1570237858
Signed-off-by: Jakub Sokołowski <jakub@status.im>
Added a second example inside the `typedthreads` file.
Also, add a more detailed introduction. When Nim is one's first
programming language, a short explanation of what a thread is might not
hurt.
For reference, the thread documentation of other languages looks like
this:
- https://en.cppreference.com/w/cpp/thread/thread
- https://doc.rust-lang.org/std/thread/
The documentation of a module is the first place one will look when
using a standard library feature, so I think it is important to have a
few usable examples for the main modules.
This is the example added
```nim
import locks
var l: Lock
proc threadFunc(obj: ptr seq[int]) {.thread.} =
withLock l:
for i in 0..<100:
obj[].add(obj[].len * obj[].len)
proc threadHandler() =
var thr: array[0..4, Thread[ptr seq[int]]]
var s = newSeq[int]()
for i in 0..high(thr):
createThread(thr[i], threadFunc, s.addr)
joinThreads(thr)
echo s
initLock(l)
threadHandler()
deinitLock(l)
```
Sharing memory between threads is very very common, so I think having an
example showcasing this is crucial.
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
## Reprodution
if on Windows:
```Nim
when defined(windows):
var file: File
let succ = file.open(<aFileHandle>)
```
then `succ` will be false.
If tested, it can be found to fail with errno `22` and message: `Invalid
argument`
## Problem
After some investigations and tests,
I found it's due to the `mode` argument for `fdopen`.
Currently `NoInheritFlag`(`'N'` in Windows) is added to `mode` arg
passed to `_fdopen`, but if referring to
[Windows `_fdopen`
doc](https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/fdopen-wfdopen?view=msvc-170),
you'll find there is no `'N'` describled. That's `'N'` is not accepted
by `_fdopen`.
Therefore, the demo above will fail.
## In Addition
To begin with, technologically speaking, when opening with a
`fileHandle`(or called `fd`), there is no concept of fd-inheritable as
`fd` is opened already.
In POSIX, `NoInheritFlag` is defined as `e`.
It's pointed out in [POSIX `open`
man-doc](https://www.man7.org/linux/man-pages/man3/fopen.3.html) that
`e` in mode is ignored for fdopen(),
which means `e` for `fdopen()` is not wanted, just allowed.
Therefore, better to also not pass `e` to `fdopen`
---
In all, that's this PR.
When target is nodejs,
`isAbsolute` used to only check in the POSIX flavor,
i.e. for js backend on Windows,
```nim
isAbsolute(r"C:\Windows") == false
```
This fixes it.
In doc, there are 4 references for `getAppFilename`
`getAppFilename` is still in `os`, but the references refer it as if
it's in the current module `cmdline`
why ?
- We already have an emit that does the same thing
- The name asm itself is a bit confusing, you might think it's an alias
for asm.js or something else.
- The asm keyword is used differently on different compiler targets (it
makes it inexpressive).
- Does anyone (other than some compiler libraries) use asm instead of
emit ? If yes, it's a bit strange to use asm somewhere and emit
somewhere. By making the asm keyword for js target deprecated, there
would be even less use of the asm keyword for js target, reducing the
amount of confusion.
- New users might accidentally use a non-universal approach via the asm
keyword instead of emit, and then when they learn about asm, try to
figure out what the differences are.
see https://forum.nim-lang.org/t/10821
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
Per manual, `panics:on` affects _only_ `Defect`:s - thus `sysFatal`
should not redirect any other exceptions.
Also, when `sysFatal` is used in `nimPanics` mode, it should use regular
exception handling pipeline to ensure exception hooks are called
consistently for all raised defects.
At least on modern Nim `tempfiles` is not usable if the user has
https://github.com/oprypin/nim-random installed, because the compiler
picks the nimble path over the stdlib path (apparently).
Theoretical Benefits / Plans:
- Typed assembler-like language.
- Allows for a CPS transformation.
- Can replace the existing C backend by a new C backend.
- Can replace the VM.
- Can do more effective "not nil" checking and static array bounds
checking.
- Can be used instead of the DFA.
- Easily translatable to LLVM.
- Reasonably easy to produce native code from.
- Tiny memory consumption. No pointers, no cry.
**In very early stages of development.**
Todo:
- [x] Map Nim types to IR types.
- [ ] Map Nim AST to IR instructions:
- [x] Map bitsets to bitops.
- [ ] Implement string cases.
- [ ] Implement range and index checks.
- [x] Implement `default(T)` builtin.
- [x] Implement multi string concat.
- [ ] Write some analysis passes.
- [ ] Write a backend.
- [x] Integrate into the compilation pipeline.
- `copyFile` allows to specify `bufferSize` instead of hardcoded wrong
value. Tiny diff.
# Performance
- 1200% Performance improvement.
# Check it yourself
Execute:
```bash
for i in $(seq 0 10); do
bs=$((1024*2**$i))
printf "%7s Kb\t" $bs
timeout --foreground -sINT 2 dd bs=$bs if=/dev/zero of=/dev/null 2>&1 | sed -n 's/.* \([0-9.,]* [GM]B\/s\)/\1/p'
done
```
(This script can be ported to PowerShell for Windows I guess, it works
in Windows MinGW Bash anyways).
# Stats
- Hardcoded `8192` or `8000` Kb bufferSize gives `5` GB/s.
- Setting `262144` Kb bufferSize gives `65` GB/s (script suggestion).
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
* make destructors accept non var parameters
* define nimAllowNonVarDestructor
* add a test case and a changelog
* update documentation and error messages
* deprecate destructors taking 'var T'
