-autofree tries to free const fixed size arrays

[spiveeworks]

Describe the bug

When declaring a fixed size array that requires some kind of cleanup, using -autofree causes cgen to call array_free on the array itself.

This bug can be triggered declaring such an array, or simply by importing time, since time declares an array like this.

Reproduction Steps

const my_words := ["foo", "bar", "baz", "quux"]

for word in words {
    println("${word}")
}

run with `v -autofree run fixed_size_autofree_bug.v

Expected Behavior

The program to print the words and exit cleanly.

Current Behavior

The program crashes during _vcleanup:

foo
bar
baz
quux
Unhandled Exception 0xC0000374
14: RtlIsZeroMemory            ?? : address = 0x1f434d9aac0
13: RtlIsZeroMemory            ?? : address = 0x1f434d9ad80
12: RtlpNtSetValueKey          ?? : address = 0x1f434d9abf0
11: RtlpNtSetValueKey          ?? : address = 0x1f434d9ad30
10: RtlpNtSetValueKey          ?? : address = 0x1f434d9ad90
9 : RtlGetCurrentServiceSessionId  ?? : address = 0x1f434d9abb0
8 : RtlFreeHeap                ?? : address = 0x1f434d9add0
7 : free_base                  ?? : address = 0x1f434d9adc0
6 : v_free                     ?? : address = 0x1f434d9adf0
5 : array_free                 ?? : address = 0x1f434d9ad20
4 : vcleanup                   ?? : address = 0x1f434d9ac20
3 : wmain                      ?? : address = 0x1f434d9ada0
2 : __scrt_common_main_seh     D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288
1 : BaseThreadInitThunk        ?? : address = 0x1f434d9adb0
0 : RtlUserThreadStart         ?? : address = 0x1f434d9aba0

Possible Solution

The C code generates these definitions:

// ...line 2059
Array_fixed_string_4 _const_main__words; // inited later
// ...line 13095
void _vcleanup(void) {
	// Cleanups for module main :
	array_free(&_const_main__words);

	// Cleanups for module builtin :
	IError_free(&_const_none__);

	// Cleanups for module strconv :

	// Cleanups for module math.bits :

	// Cleanups for module strings :

	array_free(&as_cast_type_indexes);
}

The line array_free(&_const_main__words); is what causes the crash. Instead of generating this it should be generating some other cleanup code.

Additional Information/Context

Running on Windows with msvc.

This bug can also be triggered by simply importing time in a program that uses -autofree, due to a fixed-size array of strings being declared there:
https://github.com/vlang/v/blob/master/vlib/time/time.v#L4

V version

V 0.4.5 ad17be5

Environment details (OS name and version, etc.)

V full version: V 0.4.5 386bd77.ad17be5
OS: windows, Microsoft Windows 10 Pro v19045 64-bit
Processor: 4 cpus, 64bit, little endian,

getwd: C:\Users\Owner\Code\v-experiments\fixed_size_autofree_bug
vexe: C:\Program Files\v\v.exe
vexe mtime: 2024-04-07 05:22:56

vroot: contains spaces, value: C:\Program Files\v
VMODULES: OK, value: C:\Users\Owner.vmodules
VTMP: OK, value: C:\Users\Owner\AppData\Local\Temp\v_0

Git version: git version 2.37.2.windows.2
Git vroot status: weekly.2024.14-26-gad17be5d (1 commit(s) behind V master)
.git/config present: true

CC version: Error: 'cc' is not recognized as an internal or external command,
operable program or batch file.

thirdparty/tcc: N/A

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[felipensp]

It seems a windows-only issue.