ZON unexpected field error underscors wrong code

[AndrewKraevskii]

Zig Version

0.14.0-dev.3267+59dc15fa0

Steps to Reproduce and Observed Output

// zon.zon
.{
    .baz = "baz",
}
// main.zig
comptime {
    _ = @as(struct { bar: []const u8 }, @import("zon.zon"));
}

> zig test main.zig
zon.zon:2:12: error: unexpected field 'baz'
    .baz = "baz",
           ^~~~~
main.zig:2:49: note: imported here
    _ = @as(struct { bar: []const u8 }, @import("zon.zon"));

Expected Output

I expect to get this error

> zig test main.zig
zon.zon:2:5: error: unexpected field 'baz'
    .baz = "baz",
    ^~~~
main.zig:2:49: note: imported here
    _ = @as(struct { bar: []const u8 }, @import("zon.zon"));

[alexrp]

cc @MasonRemaley

[MasonRemaley]

Thanks for the report!

@mlugg I started to fix this to underline the right part of the source, but then I noticed that you've managed to get things set up nicely where LowerZon doesn't directly access the AST anymore.

Would it cause any problems for me to cause getTree on error in order to determine the correct error location here?

[mlugg]

@MasonRemaley Rather than using getTree... situations like this are exactly what LazySrcLoc is made to deal with! The idea is that you create a LazySrcLoc which represents the location you're trying to actually point to, without actually doing the work of computing it. That work is deferred for later.

In this case, what you want is a LazySrcLoc with .offset = .{ .node_offset_field_name_init = the_init }. That field of Offset takes the source node of the RHS of = in a struct initializer, and turns it into the span of the token to the left of = -- that is, the field name.