Generated function invoking bound function crashes the compiler

[SpexGuy]

Attempting to compile this code crashes the compiler:

const std = @import("std");
const warn = std.debug.warn;

const TestStruct = struct {
    name: []const u8,

    fn func1(self: TestStruct) void {
        warn("func1: {}\n", self.name);
    }

    fn func2(self: TestStruct) void {
        warn("func2: {}\n", self.name);
    }
};

const VoidFn = fn () void;

fn nastyClosure(comptime bound_fn: var) VoidFn {
    const Codegen = struct {
        fn invoke() void {
            bound_fn();
        }
    };
    return Codegen.invoke;
}

pub fn main() void {
    var inst = TestStruct{ .name = "FirstName" };
    var functions: [4]VoidFn = undefined;
    functions[0] = nastyClosure(inst.func1);
    functions[1] = nastyClosure(inst.func2);
    inst.name = "LastName";
    functions[2] = nastyClosure(inst.func1);
    functions[3] = nastyClosure(inst.func2);

    for (functions) |func| {
        func();
    }
}

Unreachable at /deps/zig/src/analyze.cpp:6903 in const_values_equal. This is a bug in the Zig compiler.

Unable to dump stack trace: debug info stripped

Compiler returned: 255

[SpexGuy]

This smaller one generates invalid IR:

const TestStruct = struct {
    name: []const u8,

    fn func1(self: TestStruct) void {}
};

const VoidFn = fn () void;

fn nastyClosure(comptime bound_fn: var) VoidFn {
    const Codegen = struct {
        fn invoke() void {
            bound_fn();
        }
    };
    return Codegen.invoke;
}

pub fn main() void {
    var inst = TestStruct{ .name = "FirstName" };
    _ = nastyClosure(inst.func1);
}

broken LLVM module found: Instruction does not dominate all uses!

  %inst = alloca %TestStruct, align 8

  call fastcc void @TestStruct.func1(%TestStruct* %inst), !dbg !13034


This is a bug in the Zig compiler.

Unable to dump stack trace: debug info stripped

Compiler returned: 255

[SpexGuy]

If TestStruct is zero-size, it compiles and I can invoke the function. That might also be a bug.

[SpexGuy]

Related: #141

[Vexu]

BoundFn has been removed.