It seems like var is not fully populated here, ie, var->var is always null. Any idea why?

Seems like this might be because the variable is not resolved (ie, the TldResolution value is unresolved). It looks like resolution happens in codegen_build, which the JSON driver in main.cpp is calling - any idea why the code is not being resolved? Here is how I'm testing:

const Aaaaaaaa = struct {
  x: u8
};

pub fn main() void {
  var a = Aaaaaaaa { .x = 3 };
  const std = @import("std");
  std.debug.warn("{}\n", a.x);
}

I pushed changes to your branch merging conflicts with master. I tried testing the code with this file:

pub fn main() void {
}

and the command: zig json test.zig

the result was an empty array: [ ].

what have you been using to test?

Sorry, I didn't take into account your comment above. I tried with

const Aaaaaaaa = struct {
  x: u8
};

pub fn main() void {
  var a = Aaaaaaaa { .x = 3 };
  const std = @import("std");
  std.debug.warn("{}\n", a.x);
}

but zig json still gives an empty output. is that what you've been getting so far?

I pushed a version that I rebased onto master and tested. Can you try again? Maybe there was an issue with the merge.

I'm running like this

zig json hello.zig

where hello.zig is the file above.

I found the issue (I hard-coded the path to restrict output) - it should work now, though everything is still unresolved.

Try adding this to your test file:

export fn foo() void {
    var a: Aaaaaaaa = undefined;
}

you can see that foo as well as Aaaaaaa are now resolved.

looks like the code in build-exe that detects we should add std/special/bootstrap.zig to the compilation isn't triggering when you do zig json.

    if (!g->is_test_build && g->zig_target.os != OsFreestanding &&
        !g->have_c_main && !g->have_winmain && !g->have_winmain_crt_startup &&
        ((g->have_pub_main && g->out_type == OutTypeObj) || g->out_type == OutTypeExe))
    {
        g->bootstrap_import = add_special_code(g, create_bootstrap_pkg(g, g->root_package), "bootstrap.zig");
    }

I bet it's the out_type

            } else if (strcmp(arg, "json") == 0) {
                cmd = CmdJson;
                out_type = OutTypeJson;

I think that instead of trying to make zig json act like zig build-exe, we should modify the lazy analysis code to check every top level declaration when out_type == OutTypeJson. We will do something similar to this for autogenerated documentation.

Where you would add code to check all top level decls:

analyze.cpp:3066 in
static void add_top_level_decl(CodeGen *g, ScopeDecls *decls_scope, Tld *tld)

    if (is_export) {
        g->resolve_queue.append(tld);

move that to outside the if.

I think you maybe want to use

const char *type_id_name(TypeTableEntryId id);

instead of this?

Done