`reset`, `wasMoved` and `move` doesn't support primitive types, which
generate `null` for these types. It is now produce `x = default(...)` in
the backend. Ideally it should be done by ast2ir in the future
fixes#4695
ref https://github.com/nim-lang/Nim/pull/15818
Since `nkState` is only for the main loop state labels and `nkGotoState`
is used only for dispatching the `:state` (since
https://github.com/nim-lang/Nim/pull/7770), it's feasible to rewrite the
loop body into a single case-based dispatcher, which enables support for
JS, VM backend. `nkState` Node is replaced by a label and Node pair and
`nkGotoState` is only used for intermediary processing. Backends only
need to implement `nkBreakState` and `closureIterSetupExc` to support
closure iterators.
pending https://github.com/nim-lang/Nim/pull/23484
<del> I also observed some performance boost for C backend in the
release mode (not in the danger mode though, I suppose the old
implementation is optimized into computed goto in the danger mode)
</del>
allPathsAsgnResult???
The fix to the atomicArc looks to use `-1` as the check value from the
`SharedPtr` solution. However, it should be `-rcIncrement` since the
refcount is bit shifted in ARC/ORC.
I discovered this playing around doing atomic updates of refcounts in a
user library.
Related to https://github.com/nim-lang/Nim/issues/22711
@ringabout I believe you ported the sharedptr fix?
The documentation links for `parentDir()` and `getCurrentDir()` are
broken as they are no longer part of `std/os`. Link changed to
`std/private/ospaths2`.
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>
I have made `realloc` absorb unused adjacent memory, which improves the
performance. I'm investigating whether `deallocOsPages` can be used to
improve memory comsumption.
**TODO**
- [x] fixes changelog
With the new option `nimPreviewVtables`, `methods` are confined in the
same module where the type of the first parameter is defined
- [x] make it opt in after CI checks its feasibility
## In the following-up PRs
- [ ] in the following PRs, refactor code into a more efficient one
- [ ] cpp needs special treatments since it cannot embed array in light
of the preceding limits: ref
https://github.com/nim-lang/Nim/pull/20977#discussion_r1035528927; we
can support cpp backends with vtable implementations later on the
comprise that uses indirect vtable access
---------
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.
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.
I couldn't find any documentation on the syntax for --hint:X:on|off with
`nimscript` except in [this old forum
post](https://forum.nim-lang.org/t/8526#55236).
```nim
echo newString(8)
```
results in:
```
D:\User\test.js:25
var code_33556944 = c_33556931.toString(16);
^
TypeError: Cannot read properties of undefined (reading 'toString')
at toJSStr (D:\User\test.js:25:50)
at rawEcho (D:\User\test.js:70:16)
at Object.<anonymous> (D:\User\test.js:101:1)
at Module._compile (node:internal/modules/cjs/loader:1095:14)
at Object.Module._extensions..js (node:internal/modules/cjs/loader:1147:10)
at Module.load (node:internal/modules/cjs/loader:975:32)
at Function.Module._load (node:internal/modules/cjs/loader:822:12)
at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
at node:internal/main/run_main_module:17:47
Node.js v17.0.1
Error: execution of an external program failed: '"C:\Program Files\nodejs\node.exe" --unhandled-rejections=strict D:\User\test.js'
```
`{.push overflowChecks: off.}` works in backends. Though it could be
implemented as a magic function.
By inspecting the generated C code, the overflow check is eliminated in
the debug or release mode.
Likewise, the index checking is probably not needed.
