Casting bool to pointer type results in invalid zig

[Yeaseen]

Zig Version

0.14.0-dev.3271+bd237bced

Steps to Reproduce and Observed Behavior

Source C code:

#include <stdbool.h>
void func(bool b) {
    void* x = (void*)b;
}

translate-c fails to translate casting of bool to pointer

Translated Zig Code:

pub export fn func(arg_b: bool) void {
    var b = arg_b;
    _ = &b;
    var x: ?*anyopaque = @as(?*anyopaque, @intFromBool(b));
    _ = &x;
}

Zig build error:

runner.zig:60:43: error: expected type '?*anyopaque', found 'u1'
    var x: ?*anyopaque = @as(?*anyopaque, @intFromBool(b));

Expected Behavior

zig translate-c should correctly handle the cast from bool (u1) to void* (?*anyopaque) in a safe and Zig-compliant way.

[chrboesch]

I think your cast is not correct, because @intFromBool gives you an integer representation of the value, not the address. Try this:

pub export fn func(arg_b: bool) void {
    var b = arg_b;
    var x = @as(?*anyopaque, @ptrCast(&b));
    _ = &x;
}

[Yeaseen]

The translated incorrect zig code I provided here was produced by zig translate-c

[leecannon]

The original c code is casting the value of the bool to a pointer so the equivalent zig code would be const x: *anyopaque = @ptrFromInt(@intFromBool(b));

[chrboesch]

Ok, got it. Even if the C example doesn't make sense. ;-)

[chrboesch]

So, this is then the correct translation of the C example:

pub export fn func(arg_b: bool) void {
    var b = arg_b;
    _ = &b;
    var x: ?*anyopaque = @as(?*anyopaque, @ptrFromInt(@intFromBool(b)));
    _ = &x;
}

There is a missing @ptrFromInt, then we get address 00000000 or 00000001.

[Yeaseen]

Ok, got it. Even if the C example doesn't make sense. ;-)

True. However, edge cases are lovely to explore.