Panic in compiler when user code has function named panic

[widlarizer]

Zig Version

0.14.0-dev.2634+b36ea592b

Steps to Reproduce and Observed Behavior

const std = @import("std");

fn maybeError(x: u32) !u32 {
    return if (x % 2 == 0) error.Error else x;
}

export fn main() noreturn {
    const x = maybeError(5) catch panic();
    std.debug.print("{}\n", .{x});

    while (true) {}
}

pub fn panic() noreturn {
    while (true) {}
}

zig build-obj main.zig has the following output

thread 19206 panic: parameter count mismatch calling builtin fn, expected 0, found 3
Unable to dump stack trace: debug info stripped
fish: Job 1, 'nix run 'github:mitchellh/zig-o…' terminated by signal SIGABRT (Abort)

Expected Behavior

0.13.0 prints an error and doesn't crash:

/nix/store/s3nq31mhm8gxkq691p5w6q61ficw1hvr-zig-0.13.0/lib/std/builtin.zig:751:9: error: expected type 'fn ([]const u8, ?*builtin.StackTrace, ?usize) noreturn', found 'fn () noreturn'
    root.panic
    ~~~~^~~~~~
/nix/store/s3nq31mhm8gxkq691p5w6q61ficw1hvr-zig-0.13.0/lib/std/builtin.zig:751:9: note: function with 0 parameters cannot cast into a function with 3 parameters

[mark-rushakoff]

I think this is intended behavior: https://ziglang.org/documentation/master/#panic

By default the panic handler function calls the public panic function exposed in the root source file...

Presumably the parameter count mismatch error is because your panic function doesn't accept the single []const u8 parameter.

[Vexu]

It should show the same error message that it used to show in 0.13.0.

[mlugg]

This happens because Sema fails to validate the type of the panic function. Regressed by #21520.

[widlarizer]

@mark-rushakoff I think we have a misunderstanding. I'm pretty sure using the @panic builtin should cause a panic in the program when it is run, not in the compiler when it is compiled :D