Incorrect flexible array member C translation #211
Description
Zig Version
0.16.0-dev.747+493ad58ff
Steps to Reproduce and Observed Behavior
This C struct with flexible array member:
typedef struct {
int object_header;
void* object_fields[0];
} m_object;
Gets translated to:
pub const m_object = extern struct {
object_header: c_int = 0,
_object_fields: [0]?*anyopaque = @import("std").mem.zeroes([0]?*anyopaque),
pub fn object_fields(self: anytype) __helpers.FlexibleArrayType(@TypeOf(self), @typeInfo(@TypeOf(self.*._object_fields)).array.child) {
return @ptrCast(&self.*._object_fields);
}
};
Which in turn, when trying to call it like this:
const fields = obj.object_fields();
Fails with:
.zig-cache/o/f9246e760d2eb128826c0b863b897370/cimport.zig:564:16: error: @ptrCast increases pointer alignment
return @ptrCast(&self.*._object_fields);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.zig-cache/o/f9246e760d2eb128826c0b863b897370/cimport.zig:564:25: note: '*align(1) [0]?*anyopaque' has alignment '1'
return @ptrCast(&self.*._object_fields);
^~~~~~~~~~~~~~~~~~~~~~
.zig-cache/o/f9246e760d2eb128826c0b863b897370/cimport.zig:564:16: note: '[*c]?*anyopaque' has alignment '8'
.zig-cache/o/f9246e760d2eb128826c0b863b897370/cimport.zig:564:16: note: use @alignCast to assert pointer alignment
Struct comes from runtime.h which is @cImport and link with runtime.c: library.root_module.addCSourceFile(.{ .file = b.path("runtime.c") });
Expected Behavior
Probably expected:
pub const m_object = extern struct {
object_header: c_int = 0,
_object_fields: [0]?*anyopaque = @import("std").mem.zeroes([0]?*anyopaque),
pub fn object_fields(self: anytype) __helpers.FlexibleArrayType(@TypeOf(self), @typeInfo(@TypeOf(self.*._object_fields)).array.child) {
return @ptrCast(&self.*._object_fields);
}
};