Function getGraph [src]
Intended to be used during the make phase only.
Given that root is the root Module of a compilation, return all Modules
in the module graph, including root itself. root is guaranteed to be the
first module in the returned slice.
  Prototype
 pub fn getGraph(root: *Module) Graph  Parameters
root: *Module Source
 pub fn getGraph(root: *Module) Graph {
    if (root.cached_graph.modules.len != 0) {
        return root.cached_graph;
    }
    const arena = root.owner.graph.arena;
    var modules: std.AutoArrayHashMapUnmanaged(*std.Build.Module, []const u8) = .empty;
    var next_idx: usize = 0;
    modules.putNoClobber(arena, root, "root") catch @panic("OOM");
    while (next_idx < modules.count()) {
        const mod = modules.keys()[next_idx];
        next_idx += 1;
        modules.ensureUnusedCapacity(arena, mod.import_table.count()) catch @panic("OOM");
        for (mod.import_table.keys(), mod.import_table.values()) |import_name, other_mod| {
            modules.putAssumeCapacity(other_mod, import_name);
        }
    }
    const result: Graph = .{
        .modules = modules.keys(),
        .names = modules.values(),
    };
    root.cached_graph = result;
    return result;
}