Unhandled Exception 0x149f6f0

[koplenov]

V version: V 0.4.9 496451e, press to see full `v doctor` output

V full version	V 0.4.9 4fcd94a.496451e
OS	windows, Њ ©Єа®б®дв Windows 10 Pro 19045 64-а §ап¤­ п
Processor	28 cpus, 64bit, little endian, Intel(R) Xeon(R) CPU E5-2680 v4 @ 2.40GHz
Memory	18.78GB/31.86GB
V executable	C:\Dev\Progs\v\v.exe
V last modified time	2025-01-17 20:10:01
V home dir	OK, value: C:\Dev\Progs\v
VMODULES	OK, value: C:\Users\koplenov.vmodules
VTMP	OK, value: C:\Users\koplenov\AppData\Local\Temp\v_0
Current working dir	OK, value: C:\Dev\Zone\mam_v\treevee\src\repro
Git version	git version 2.42.0.windows.2
V git status	weekly.2025.1-72-g496451ec (12 commit(s) behind V master)
.git/config present	true
cc version	N/A
gcc version	gcc (MinGW-W64 x86_64-ucrt-posix-seh, built by Brecht Sanders, r4) 13.2.0
clang version	clang version 18.1.2
msvc version	N/A
tcc version	tcc version 0.9.27 (x86_64 Windows)
tcc git status	thirdparty-windows-amd64 b425ac82
emcc version	N/A
glibc version	N/A

What did you do?
./v -g -o vdbg cmd/v && ./vdbg .\main.v && C:\Dev\Zone\mam_v\treevee\src\repro\main.exe

module main

pub struct Tree {
	value string
}
pub type TreeBelt = map[string]fn (input string) []string

fn main() {
	tree := Tree{
		value: 'he he'
	}

	mut belt := TreeBelt(map[string]fn (string) []string){
		"bar" : fn [tree](input string) []string {
			return [tree.value + input]
		}
	}

	mut belt2 := TreeBelt(map[string]fn (string) []string){}
	belt2['bar'] = fn [tree](input string) []string {
		return [tree.value + input]
	}

	// ok
	println(belt["bar"]) // fn (string) []string
	println(belt2["bar"]) // fn (string) []string


	println(belt["bar"]("foo")) // throw Unhandled Exception 0x149f6f0
	println(belt2["bar"]("fo")) // ok
}

What did you see?

fn (string) []string
fn (string) []string
Unhandled Exception 0x149f6f0
C:/Users/koplenov/AppData/Local/Temp/v_0/main.01JHZ9T7ZR1QFSFA4GXGBZQ1Q5.tmp.c:4464: at print_backtrace_skipping_top_frames_tcc: Backtrace
C:/Users/koplenov/AppData/Local/Temp/v_0/main.01JHZ9T7ZR1QFSFA4GXGBZQ1Q5.tmp.c:4450: by print_backtrace_skipping_top_frames
C:/Users/koplenov/AppData/Local/Temp/v_0/main.01JHZ9T7ZR1QFSFA4GXGBZQ1Q5.tmp.c:5056: by unhandled_exception_handler
7ffff6d88b1c : by ???
RUNTIME ERROR: invalid memory access

What did you expect to see?

Execution without Unhandled Exception error

Note

You can use the 👍 reaction to increase the issue's priority for developers.

Please note that only the 👍 reaction to the issue itself counts as a vote.
Other reactions and those to comments will not be taken into account.

[huly-for-github]

Connected to Huly®: V_0.6-21951

[JalonSolov]

On Linux, it looks almost the same, with just as little indication of the actual error.

[jalon@7950x ~]$ v run main.v
fn (string) []string
fn (string) []string
0x00000000: at ???: RUNTIME ERROR: invalid memory access
/tmp/v_1000/main.01JHZMSVJPWERR1XHF6FMAVRG8.tmp.c:7219: by main
[jalon@7950x ~]$ v -g run main.v
fn (string) []string
fn (string) []string
0x00000000: at ???: RUNTIME ERROR: invalid memory access
/tmp/v_1000/../../../../../../tmp/v_1000/main.01JHZMT483XZJ7D0CS4CPGH634.tmp.c:14068: by main
[jalon@7950x ~]$ 

[yuyi98]

The usage is wrong.

pub struct Tree {
	value string
}
pub type TreeBelt = map[string]fn (input string) []string

fn main() {
	tree := Tree{
		value: 'he he'
	}

	mut belt := TreeBelt({
		"bar" : fn [tree](input string) []string {
			return [tree.value + input]
		}
	})

	mut belt2 := TreeBelt(map[string]fn (string) []string{})
	belt2['bar'] = fn [tree](input string) []string {
		return [tree.value + input]
	}

	// ok
	println(belt["bar"]) // fn (string) []string
	println(belt2["bar"]) // fn (string) []string


	println(belt["bar"]("foo"))
	println(belt2["bar"]("fo")) // ok
}

PS D:\Test\v\tt1> v run .
fn (string) []string
fn (string) []string
['he hefoo']
['he hefo']

[jorgeluismireles]

The usage is wrong.

Just to clarify for our eyes, I guess you mean, change this:

	mut belt := TreeBelt(map[string]fn (string) []string){
		"bar" : fn [tree](input string) []string {
			return [tree.value + input]
		}
	}

by this:

	mut belt := TreeBelt({
		"bar" : fn [tree](input string) []string {
			return [tree.value + input]
		}
	})

[spytheman]

why did this parse?

TreeBelt(map[string]fn (string) []string){
        "bar" : fn [tree](input string) []string {

[spytheman]

oh... it parsed as:

mut belt :=  TreeBelt(    map[string]fn (string) []string     )`

... then followed by (on the same line):

{
        "bar" : fn [tree](input string) []string {
...
}

[spytheman]

The compiler just ignores the second map initialization expression (since it was not used for anything), and considers the first one to be a valid cast (but it should not have).

[spytheman]

I think that mut belt := TreeBelt(map[string]fn (string) []string) should have been a parser error.

[spytheman]

A more minimal reproduction is just:

pub type TreeBelt = map[string]fn (input string) []string
mut tb := TreeBelt(   map[string]fn (string) []string   )
println(tb)

which currently produces: TreeBelt({})

[spytheman]

Simplifying it further:

mut tb := map[string]string
println(tb)