./v test vlib/v/tests/generics_chans_select_test.v fails

[bakul]

Describe the bug

This is on FreeBSD-14.0-p4. I did a fresh install of v with git clone & gmake. There is a problem wit tcc so I removed thirdparty/tcc. Running the above test fails. Every other test succeeds.

Reproduction Steps

Do a fresh install on a freebsd-14.0 machine (patch number doesn't matter). Make sure boehm-gc-threaded pkg is installed. Then gmake, remove thirdparty/gcc and then run the above test.

Expected Behavior

The test should pass.

Current Behavior

See below

Possible Solution

No idea.

Additional Information/Context

./v test vlib/v/tests/generics_chans_select_test.v
---- Testing... -----------------------------------------------------------------
 FAIL   724.968 ms vlib/v/tests/generics_chans_select_test.v
==================
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/v_1001/tsession_262e37012000_705016034380/generics_chans_select_test.17295752555952635124.tmp.c:25386:6: error: incompatible pointer to integer conversion assigning to 'bool' (aka 'unsigned char') from 'anon_fn_main__foo__bool' (aka 'unsigned char (*)(struct main__Foo)') [-Wint-conversion]
                        b = ( (*(anon_fn_main__foo__bool*)_t5.data));
                          ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/v_1001/tsession_262e37012000_705016034380/generics_chans_select_test.17295752555952635124.tmp.c:25387:4: warning: expression result unused [-Wunused-value]
                        e;
                        ^
/tmp/v_1001/tsession_262e37012000_705016034380/generics_chans_select_test.17295752555952635124.tmp.c:25452:6: error: incompatible pointer to integer conversion assigning to 'bool' (aka 'unsigned char') from 'anon_fn_main__bar__bool' (aka 'unsigned char (*)(struct main__Bar)') [-Wint-conversion]
                        b = ( (*(anon_fn_main__bar__bool*)_t5.data));
                          ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/v_1001/tsession_262e37012000_705016034380/generics_chans_select_test.17295752555952635124.tmp.c:25453:4: warning: expression result unused [-Wunused-value]
                        e;
...
==================
(Use `v -cg` to print the entire error message)

builder error:
==================
C error. This should never happen.

This is a compiler bug, please report it using `v bug file.v`.

https://github.com/vlang/v/issues/new/choose

You can also use #help on Discord: https://discord.gg/vlang

---------------------------------------------------------------------------------
Failed command 1:    '/home/bakul/v/v'   -o '/tmp/v_1001/tsession_262e37012000_705016034380/01HJS780B8S78RYTHJSNTT2VPZ/generics_chans_select_test' '/home/bakul/v/vlib/v/tests/generics_chans_select_test.v'
Summary for all V _test.v files: 1 failed, 1 total. Runtime: 730 ms, on 1 job.

V version

V 0.4.3 680b0d4

Environment details (OS name and version, etc.)

V full version: V 0.4.3 2dce525.680b0d4
OS: freebsd, 14.0-RELEASE-p4, FreeBSD 14.0-RELEASE-p4 #47 releng/14.0-n265400-4edf3b80733e: Tue Dec 19 15:35:46 PST 2023     xxx:/usr/obj/home/FreeBSD/releng-14/amd64.amd64/sys/GENERIC
Processor: 1 cpus, 64bit, little endian

getwd: /home/bakul/v
vexe: /home/bakul/v/v
vexe mtime: 2023-12-28 22:02:16

vroot: OK, value: /home/bakul/v
VMODULES: OK, value: /home/bakul/.vmodules
VTMP: OK, value: /tmp/v_1001

Git version: git version 2.42.0
Git vroot status: 680b0d46
.git/config present: true

CC version: FreeBSD clang version 16.0.6 (https://github.com/llvm/llvm-project.git llvmorg-16.0.6-0-g7cbf1a259152)
thirdparty/tcc: N/A

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[bakul]

The test succeeds on FreeBSD-13.2-STABLE, using tcc. It fails when cc is used in place of tcc.

[spytheman]

I can reproduce the same cgen error with clang 16.0.6 on windows too.

[spytheman]

It compiles fine with clang 15.0.0 and lower.

[shove70]

This test case has an error, see the comments in the code:

import time

pub type EventListener[T] = fn (T) !

@[heap]
struct Chan[T] {
	c chan T
}

pub type Check[T] = fn (T) bool

struct EventWaiter[T] {
	check ?Check[T]
	c     &Chan[T]
}

pub struct EventController[T] {
mut:
	id        int
	wait_fors map[int]EventWaiter[T]
	listeners map[int]EventListener[T]
}

fn (mut ec EventController[T]) generate_id() int {
	return ec.id++
}

@[params]
pub struct EmitOptions {
pub:
	error_handler ?fn (int, IError)
}

pub fn (mut ec EventController[T]) emit(e T, options EmitOptions) {
	for i, w in ec.wait_fors {
		mut b := false
		if w.check != none {
			b = (w.check or { panic(err) }) // Here !!!!!!, w.check is a ?fn type, the correct code would be:  b = w.check or { panic(err) }(e),   The 'e' in the below row should be the call arg here.
			e
		} else {
			b = true
		}
		if b {
			w.c.c <- e
			ec.wait_fors.delete(i)
			return
		}
	}
	mut ts := []thread{}
	for i, l in ec.listeners {
		ts << spawn fn [options] [T](f EventListener[T], j int, e T) {
			f(e) or {
				if g := options.error_handler {
					g(j, err)
				}
			}
		}(l, i, e)
	}
	ts.wait()
}

@[params]
pub struct EventWaitParams[T] {
pub:
	check   ?Check[T]
	timeout ?time.Duration
}

pub struct Awaitable[T] {
	id      int
	timeout ?time.Duration
	c       Chan[T]
mut:
	controller &EventController[T]
}

struct Zero[T] {
	e T
}

pub fn (mut a Awaitable[T]) do() ?T {
	defer {
		a.controller.wait_fors.delete(a.id)
	}
	if timeout := a.timeout {
		mut e := Zero[T]{}.e
		select {
			e = <-a.c.c {
				r := e
				return r
			}
			timeout.nanoseconds() {
				return none
			}
		}
	}
	return <-a.c.c
}

pub fn (mut ec EventController[T]) wait(params EventWaitParams[T]) Awaitable[T] {
	mut c := Chan[T]{}
	id := ec.generate_id()
	ec.wait_fors[id] = EventWaiter[T]{
		check: params.check
		c: &mut c
	}
	return Awaitable[T]{
		id: id
		timeout: params.timeout
		controller: unsafe { &mut ec }
		c: c
	}
}

struct Foo {}

struct Bar {}

fn main() {
	x := EventController[Foo]{}
	println(x)
	y := EventController[Bar]{}
	println(y)
	assert true
}

There are 3 issues in this issue:

1. The ?fn type assigned to the bool type, checker does not report an error
2. Even if the code in test is correct, cgen has another problem.
3. Fmt formats it into the wrong code, so the wrong code in this test is actually caused by fmt.

So there are 3 issues that need to be fixed

---

The root cause is the Parser.

[shove70]

Simplified:

type Fn[T] = fn (arg T) bool

struct Foo[T] {
	f ?Fn[T]
}

@[params]
struct Bar {}

fn (mut f Foo[T]) method (arg T) {
	mut b := false
	if f.f != none {
		b = (f.f or { panic(err) })
		arg
	} else {
		b = true
	}
	if b {
	}
}

fn main() {
	mut foo := Foo[Bar] {
		f: fn (arg Bar) bool {
			return true
		}
	}
	foo.method(Bar{})
}