Silence non_upper_case_globals warnings in macros

The enumn and bitfield macros generate global constants based on names
that are typically in CamelCase, but the new on-by-default warning
non_upper_case_globals complains about them.

Fixes warnings of the form:
  warning: associated constant `...` should have an upper case name
when using enumn or bitfield.

BUG=None
TEST=`cargo build` without warnings

Change-Id: Id908df1dcdf58288c2cbdff574cb70be2026bde6
Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1536558
Commit-Ready: David Tolnay <dtolnay@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: David Tolnay <dtolnay@chromium.org>

2 files changed, 3 insertions, 0 deletions

diff --git a/enumn/src/lib.rs b/enumn/src/lib.rs
index f4c30a7..b928b11 100644
--- a/enumn/src/lib.rs
+++ b/enumn/src/lib.rs
@@ -182,6 +182,7 @@ fn testable_derive(input: DeriveInput) -> proc_macro2::TokenStream {
     });
 
     quote! {
+        #[allow(non_upper_case_globals)]
         impl #ident {
             pub #signature -> Option<Self> {
                 struct discriminant;
diff --git a/enumn/src/tests.rs b/enumn/src/tests.rs
index 0d9cb83..cf5dd42 100644
--- a/enumn/src/tests.rs
+++ b/enumn/src/tests.rs
@@ -17,6 +17,7 @@ fn test_repr() {
     };
     let actual = crate::testable_derive(input);
     let expected = quote! {
+        #[allow(non_upper_case_globals)]
         impl E {
             pub fn n(value: u8) -> Option<Self> {
                 struct discriminant;
@@ -48,6 +49,7 @@ fn test_no_repr() {
     };
     let actual = crate::testable_derive(input);
     let expected = quote! {
+        #[allow(non_upper_case_globals)]
         impl E {
             pub fn n<REPR: Into<i64>>(value: REPR) -> Option<Self> {
                 struct discriminant;