Large array sizes cause segfault or LLVM error

[mil]

Given example test file arraysize.zig like:

const std = @import("std");

pub fn main() void {
    var x : [2e7]u8 = undefined;
    x[1] = 2;
    std.debug.warn("Foo\n", .{});
}

Running produces segfault:

> zig run arraysize.zig
zsh: segmentation fault  zig run arraysize.zig

Changing size of array to even larger arbitrary value 2e10 produces LLVM error:

broken LLVM module found: invalid subrange count
!16474 = !DISubrange(count: -545128448, lowerBound: 0)

This is a bug in the Zig compiler.thread 9376 panic:
Unable to dump stack trace: debug info stripped
zsh: abort      zig run arraysize.zig

Maybe error message should be standardized? Or atleast compiler should try to prevent segfault case.

[mil]

> zig version
0.9.0-dev.1324+598db831f

[ghost]

The segfault comes from overflowing the stack with that 20MB array, so more or less normal behavior. Workaround: allocate large arrays on the heap 😄.

The second failure is a bug -- a more graceful error should be reported there.

[Ultra-Code]

Also had a similar issue. I realized from try and error that when I have an array on the stack greater than ~15MiB (1024 * 1024 * 15) zig build run crashes. But when I set the exe.stack_size option to a value greater than 15MiB then I can have an array buffer greater than 15MiB but zig build run still crash but zig build and running exe manually works

[nektro]

fixed by #1424 in LLVM 17