fixes#25204
```nim
of mUnaryMinusI..mAbsI: unaryArithOverflow(p, e, d, op)
of mAddI..mPred: binaryArithOverflow(p, e, d, op)
```
Arithmetic operations may raise exceptions. So we cannot entrust the
optimizer to skip `result` initialization in this situation, as
complained righteously by `gcc` and `clang`: `warning: ‘result’ may be
used uninitialized [-Wmaybe-uninitialize]`.
With this PR, `clang -c -Wuninitialized -O1 @psystem.nim.c` no longer
gives warnings
fixes#25205fixes#14873
```nim
type
SysLockObj {.importc: "pthread_mutex_t", pure, final,
header: """#include <sys/types.h>
#include <pthread.h>""", byref.} = object
when defined(linux) and defined(amd64):
abi: array[40 div sizeof(clong), clong]
```
Before this PR, in refc, `resetLoc` generates field assignments for each
fields of `importc` object. But the field `abi` is not a genuine field,
which doesn't exits in the struct. We could use `zeroMem` to reset the
memory if not leave it alone
POSIX signal has an identical definition to ISO C signal:
https://pubs.opengroup.org/onlinepubs/9799919799/functions/signal.html
```c
void (*signal(int sig, void (*func)(int)))(int);
/* more readably restated by glibc as */
typedef void (*sighandler_t)(int);
sighandler_t signal(int signum, sighandler_t handler);
```
However, std/posix had omitted the function's return value; this fixes
that.
To prevent breaking every single line of code ever that touched this
binding (including mine...), I've also made it discardable.
Additionally, I have noticed that bsd_signal's type signature is wrong -
it should have been identical to signal. But bsd_signal was already
removed in POSIX 2008, and sigaction is the recommended, portable POSIX
signal interface. So I just deleted the bsd_signal binding.
Co-authored-by: ringabout <43030857+ringabout@users.noreply.github.com>
TODO list, copied from the documentation:
- [x] compiler/platform.nim Add os/cpu properties.
- [x] lib/system.nim Add os/cpu to the documentation for system.hostOS
and system.hostCPU.
- [x] ~~compiler/options.nim Add special os/cpu property checks in
isDefined.~~ seems unnecessary; isn't dont for most CPUs
- [x] compiler/installer.ini Add os/cpu to Project.Platforms field.
- [x] lib/system/platforms.nim Add os/cpu.
- [x] ~~std/private/osseps.nim Add os specializations.~~
- [x] ~~lib/pure/distros.nim Add os, package handler.~~
- [x] ~~tools/niminst/makefile.nimf Add os/cpu compiler/linker flags.~~
already done in https://github.com/nim-lang/Nim/pull/20943
- [x] tools/niminst/buildsh.nimf Add os/cpu compiler/linker flags.
For csource:
- [x] have compiler/platform.nim updated
- [x] have compiler/installer.ini updated
- [x] have tools/niminst/buildsh.nimf updated
- [x] have tools/niminst/makefile.nimf updated
- [ ] be backported to the Nim version used by the csources
- [ ] the new csources must be pushed
- [ ] the new csources revision must be updated in
config/build_config.txt
Additionally:
- [x] check relation to https://github.com/nim-lang/Nim/pull/20943
Possible future work:
- Porting Nim to s390x-specific operating systems, notably z/OS
Co-authored-by: ringabout <43030857+ringabout@users.noreply.github.com>
...introduced by me in #24792. Sorry.
This fix doesn't avoid copying the `restrictedBody` twice in the
generated code but has the benefit of working.
Proper fix needs a detection that can set a const bool for a module
once. `when nimvm` is restricted in use and is difficult to dance
around. Some details in: #12517, #12518, #13038
I might have copied the buggy solution from some discussion and it might
have worked at some point, but it's small excuse.
fixes#24760
I tried `incl` `tfHasAsgn` to nontrivial assignment, but that solution
seems to break too many things. Instead, in this PR, `passCopyToSink`
now checks nontrivial assignment
Workaround for #24596.
I also took the liberty to disable it on all targets with GCC, since
their documentation claims that it is also enabled on -Os.
---------
Co-authored-by: ringabout <43030857+ringabout@users.noreply.github.com>
fixes#24998
Basically it retraces back to the situation before
https://github.com/nim-lang/Nim/pull/18366 and
https://github.com/nim-lang/Nim/pull/18362, i.e.
```nim
import fuzz/a
import fuzz/a
```
```nim
import fuzz/a
from buzz/a
```
```nim
import fuzz/a except nil
from fuzz/a import addInt
```
All of these cases are now flagged as invalid and triggers a
redefinition error, i.e., each module name importing is treated as
consistent as the symbol definition
kinda annoying for importing/exporting with `when conditions` though
ref https://github.com/nim-lang/Nim/issues/18762https://github.com/nim-lang/Nim/issues/20907
```nim
from std/strutils import toLower
when not defined(js):
from std/strutils import toUpper
```
Inside a signal handler, you cannot allocate memory because the signal
handler, being implemented with a C
[`signal`](https://en.cppreference.com/w/c/program/signal) call, can be
called _during_ a memory allocation - when that happens, the CTRL-C
handler causes a segfault and/or other inconsistent state.
Similarly, the call can happen from a non-nim thread or inside a C
library function call etc, most of which do not support reentrancy and
therefore cannot be called _from_ a signal handler.
The stack trace facility used in the default handler is unfortunately
beyond fixing without more significant refactoring since it uses
garbage-collected types in its API and implementation.
As an alternative to https://github.com/nim-lang/Nim/pull/25110, this PR
removes the most problematic signal handler, namely the one for SIGINT
(ctrl-c) - SIGINT is special because it's meant to cause a regular
shutdown of the application and crashes during SIGINT handling are both
confusing and, if turned into SIGSEGV, have downstream effects like core
dumps and OS crash reports.
The signal handlers for the various crash scenarios remain as-is - they
may too cause their own crashes but we're already going down in a bad
way, so the harm is more limited - in particular, crashing during a
crash handler corrupts `core`/crash dumps. Users wanting to keep their
core files pristine should continue to use `-d:noSignalHandler` - this
is usually the better option for production applications since they
carry more detail than the Nim stack trace that gets printed.
Finally, the example of a ctrl-c handler performs the same mistake of
calling `echo` which is not well-defined - replace it with an example
that is mostly correct (except maybe for the lack of `volatile` for the
`stop` variable).
Raising exceptions halfway through a memory allocation is undefined
behavior since exceptions themselves require multiple allocations and
the allocator functions are not reentrant.
It is of course also expensive performance-wise to introduce lots of
exception-raising code everywhere since it breaks many optimisations and
bloats the code.
Finally, performing pointer arithmetic with signed integers is incorrect
for example on on a 32-bit systems that allows up to 3gb of address
space for applications (large address extensions) and unnecessary
elsewhere - broadly, stuff inside the memory allocator is generated by
the compiler or controlled by the standard library meaning that
applications should not be forced to pay this price.
If we wanted to check for overflow, the right way would be in the
initial allocation location where both the size and count of objects is
known.
The code is updated to use the same arithmetic operator style as for
refc with unchecked operations rather than disabling overflow checking
wholesale in the allocator module - there are reasons for both, but
going with the existing flow seems like an easier place to start.
Because `prevFields` and `currentFields` have been already quoted by
`'`, no need to add another.
The error message was
```
The fields ''x'' and ''y'' cannot be initialized together, because they are from conflicting branches in the case object.
```
Also added some documentation to the header.
See: https://forum.nim-lang.org/t/13311
> I did try using the flag, but couldn't get it to work. If I do
-d:nimIoSelector, the defined check passes, but the other code fails to
compile because there is no const named nimIoSelector. It seemed like a
bug to me, do you have a working number compiler invocation?
Co-authored-by: ringabout <43030857+ringabout@users.noreply.github.com>
`DWORD` is defined as `int32`, so `DWORD(...)` would not work as
expected. When writing to files larger than 2GB, exception occurs:
```
unhandled exception: value out of range: 4294967295 notin -2147483648 .. 2147483647 [RangeDefect]
```
This PR is a quick fix for this.
P.S. Why `DWORD` is defined as `int32`?
fixes#25117
errors on `requiresInit` of `result` if it is used before
initialization. Otherwise
```nim
# prevent superfluous warnings about the same variable:
a.init.add s.id
```
It produces a warning, and this line prevents it from being recognized
by the `requiresInit` check in `trackProc`
fixes#24093
transforms
```nim
let a = new array[1000, byte]
block:
for _ in cast[typeof(a)](a)[]:
discard
```
into
```nim
let a = new array[1000, byte]
block:
let temp = cast[typeof(a)](a)
for _ in temp[]:
discard
```
So it keeps the same behavior with the manual version
Follow up to https://github.com/nim-lang/Nim/pull/25126
It changed `formatSize` outputs from some inputs, so some of existing
test code related to it need to be updated.
Sorry, I didn't know `tests/destructor/tnewruntime_strutils.nim` has
tests calls `formatSize`.
fixes#25066
Probably it is not worth implementing comparing pointers at compile
time. For a starter, we can improve the error message instead of letting
it crash
## Description
Fixed an inconsistency in the Nim manual's example for the `*+`
operator.
Previously, the example on line 4065 of `doc/manual.md` used variables
`a`, `b`, and `c`:
```nim
assert `*+`(3, 4, 6) == `+`(`*`(a, b), c)
```
This did not match the preceding call which directly used literals `3`,
`4`, `6`.
Updated the example to:
```nim
assert `*+`(3, 4, 6) == `+`(`*`(3, 4), 6)
```
This change makes the example consistent with the function call and
immediately understandable to readers without requiring prior variable
definitions.
## Rationale
* Improves clarity by avoiding undefined variables in a code snippet.
* Matches the example usage in the preceding line.
* Helps beginners understand the operator's behavior without additional
context.
## Changes
* **Edited**: `doc/manual.md` line 4065 — replaced variables `a`, `b`,
`c` with literals `3`, `4`, `6`.
## Issue
Closes#25084
Reverts nim-lang/Nim#25090
It seems to cause problems for C++ and i686
```
2025-08-08T02:37:55.5976232Z c:/a/nightlies/nightlies/external/mingw32/bin/../lib/gcc/i686-w64-mingw32/11.1.0/../../../../i686-w64-mingw32/bin/ld.exe: C:\Users\runneradmin\nimcache\manual_experimental_snippet_106_d\@pstd@sprivate@ssyslocks.nim.c.o:@pstd@sprivate@ssyslocks.nim.c:(.text+0x29): undefined reference to `SleepConditionVariableCS'
2025-08-08T02:37:55.5978066Z c:/a/nightlies/nightlies/external/mingw32/bin/../lib/gcc/i686-w64-mingw32/11.1.0/../../../../i686-w64-mingw32/bin/ld.exe: C:\Users\runneradmin\nimcache\manual_experimental_snippet_106_d\@pthreadpool.nim.c.o:@pthreadpool.nim.c:(.text+0x26): undefined reference to `InitializeConditionVariable'
2025-08-08T02:37:55.5980101Z c:/a/nightlies/nightlies/external/mingw32/bin/../lib/gcc/i686-w64-mingw32/11.1.0/../../../../i686-w64-mingw32/bin/ld.exe: C:\Users\runneradmin\nimcache\manual_experimental_snippet_106_d\@pthreadpool.nim.c.o:@pthreadpool.nim.c:(.text+0x116): undefined reference to `WakeConditionVariable'
2025-08-08T02:37:55.5981093Z collect2.exe: error: ld returned 1 exit status
2025-08-08T02:37:55.5988564Z Error: execution of an external program failed: 'gcc.exe -o
```
