Fixed genquery for rust targets (bazelbuild#2559)

relates to bazelbuild#2522

Author: UebelAndre

rust/private/rust.bzl

@@ -528,10 +528,6 @@ RUSTC_ATTRS = {
     "_extra_rustc_flags": attr.label(
         default = Label("//:extra_rustc_flags"),
     ),
-    "_import_macro_dep": attr.label(
-        default = Label("//util/import"),
-        cfg = "exec",
-    ),
     "_is_proc_macro_dep": attr.label(
         default = Label("//rust/private:is_proc_macro_dep"),
     ),

rust/private/utils.bzl

@@ -493,6 +493,9 @@ def get_import_macro_deps(ctx):
         list of Targets. Either empty (if the fake import macro implementation
         is being used), or a singleton list with the real implementation.
     """
+    if not hasattr(ctx.attr, "_import_macro_dep"):
+        return []
+
     if ctx.attr._import_macro_dep.label.name == "fake_import_macro_impl":
         return []
 

test/genquery/BUILD.bazel

@@ -0,0 +1,26 @@
+load("//rust:defs.bzl", "rust_binary", "rust_library")
+
+rust_library(
+    name = "bar",
+    srcs = ["bar.rs"],
+    edition = "2021",
+)
+
+genquery(
+    name = "bar_deps",
+    expression = "deps(//test/genquery:bar)",
+    scope = [":bar"],
+)
+
+rust_binary(
+    name = "foo",
+    srcs = ["foo.rs"],
+    edition = "2021",
+    deps = [":bar"],
+)
+
+genquery(
+    name = "foo_deps",
+    expression = "deps(//test/genquery:foo)",
+    scope = [":foo"],
+)

test/genquery/bar.rs

@@ -0,0 +1,3 @@
+pub fn bar() {
+    println!("Bar");
+}

test/genquery/foo.rs

@@ -0,0 +1,4 @@
+fn main() {
+    println!("foo");
+    bar::bar();
+}