Upgrade mls-rs-codec-derive to 0.1.1

This project was upgraded with external_updater.
Usage: tools/external_updater/updater.sh update external/rust/crates/mls-rs-codec-derive
For more info, check https://cs.android.com/android/platform/superproject/+/main:tools/external_updater/README.md

Test: TreeHugger
Change-Id: I54893e204654927a4e10d2b31dd9f7a450adf5f4

7 files changed, 300 insertions, 130 deletions

diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
index 425a46d..fa9e261 100644
--- a/.cargo_vcs_info.json
+++ b/.cargo_vcs_info.json
@@ -1,6 +1,6 @@
 {
   "git": {
-    "sha1": "d0b115d2ea4754006341ba23e5910d741c6263c9"
+    "sha1": "d54563f15579db6482817d2e3dbdcbc10957908c"
   },
   "path_in_vcs": "mls-rs-codec-derive"
 }
\ No newline at end of file
diff --git a/Android.bp b/Android.bp
index 1636a54..027c569 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,5 +1,7 @@
 // This file is generated by cargo_embargo.
-// Do not modify this file as changes will be overridden on upgrade.
+// Do not modify this file after the first "rust_*" or "genrule" module
+// because the changes will be overridden on upgrade.
+// Content before the first "rust_*" or "genrule" module is preserved.
 
 package {
     default_applicable_licenses: ["external_rust_crates_mls_rs_codec_derive_license"],
@@ -23,7 +25,7 @@ rust_proc_macro {
     name: "libmls_rs_codec_derive",
     crate_name: "mls_rs_codec_derive",
     cargo_env_compat: true,
-    cargo_pkg_version: "0.1.0",
+    cargo_pkg_version: "0.1.1",
     srcs: ["src/lib.rs"],
     edition: "2021",
     rustlibs: [
diff --git a/Cargo.lock b/Cargo.lock
deleted file mode 100644
index 34f52a1..0000000
--- a/Cargo.lock
+++ /dev/null
@@ -1,101 +0,0 @@
-# This file is automatically @generated by Cargo.
-# It is not intended for manual editing.
-version = 3
-
-[[package]]
-name = "darling"
-version = "0.20.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0209d94da627ab5605dcccf08bb18afa5009cfbef48d8a8b7d7bdbc79be25c5e"
-dependencies = [
- "darling_core",
- "darling_macro",
-]
-
-[[package]]
-name = "darling_core"
-version = "0.20.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "177e3443818124b357d8e76f53be906d60937f0d3a90773a664fa63fa253e621"
-dependencies = [
- "fnv",
- "ident_case",
- "proc-macro2",
- "quote",
- "strsim",
- "syn",
-]
-
-[[package]]
-name = "darling_macro"
-version = "0.20.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "836a9bbc7ad63342d6d6e7b815ccab164bc77a2d95d84bc3117a8c0d5c98e2d5"
-dependencies = [
- "darling_core",
- "quote",
- "syn",
-]
-
-[[package]]
-name = "fnv"
-version = "1.0.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
-
-[[package]]
-name = "ident_case"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
-
-[[package]]
-name = "mls-rs-codec-derive"
-version = "0.1.0"
-dependencies = [
- "darling",
- "proc-macro2",
- "quote",
- "syn",
-]
-
-[[package]]
-name = "proc-macro2"
-version = "1.0.71"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "75cb1540fadbd5b8fbccc4dddad2734eba435053f725621c070711a14bb5f4b8"
-dependencies = [
- "unicode-ident",
-]
-
-[[package]]
-name = "quote"
-version = "1.0.33"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
-dependencies = [
- "proc-macro2",
-]
-
-[[package]]
-name = "strsim"
-version = "0.10.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
-
-[[package]]
-name = "syn"
-version = "2.0.43"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee659fb5f3d355364e1f3e5bc10fb82068efbf824a1e9d1c9504244a6469ad53"
-dependencies = [
- "proc-macro2",
- "quote",
- "unicode-ident",
-]
-
-[[package]]
-name = "unicode-ident"
-version = "1.0.12"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"
diff --git a/Cargo.toml b/Cargo.toml
index a9bd0b8..090f038 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,7 @@
 [package]
 edition = "2021"
 name = "mls-rs-codec-derive"
-version = "0.1.0"
+version = "0.1.1"
 description = "Derive macro crate for mls-rs-codec"
 homepage = "https://github.com/awslabs/mls-rs"
 keywords = [
diff --git a/METADATA b/METADATA
index 57145a7..a20aed3 100644
--- a/METADATA
+++ b/METADATA
@@ -1,20 +1,24 @@
+# This project was upgraded with external_updater.
+# Usage: tools/external_updater/updater.sh update external/rust/crates/mls-rs-codec-derive
+# For more info, check https://cs.android.com/android/platform/superproject/+/main:tools/external_updater/README.md
+
 name: "mls-rs-codec-derive"
 description: "Derive macro crate for mls-rs-codec"
 third_party {
+  license_type: NOTICE
+  last_upgrade_date {
+    year: 2024
+    month: 4
+    day: 26
+  }
   identifier {
     type: "crates.io"
-    value: "https://crates.io/crates/mls-rs-codec-derive"
+    value: "https://static.crates.io/crates/mls-rs-codec-derive/mls-rs-codec-derive-0.1.1.crate"
+    version: "0.1.0"
   }
   identifier {
     type: "Archive"
     value: "https://static.crates.io/crates/mls-rs-codec-derive/mls-rs-codec-derive-0.1.0.crate"
-  }
-  version: "0.1.0"
-  # Dual-licensed, using the least restrictive per go/thirdpartylicenses#same.
-  license_type: NOTICE
-  last_upgrade_date {
-    year: 2024
-    month: 1
-    day: 4
+    version: "0.1.1"
   }
 }
diff --git a/patches/add-license-files.patch b/patches/add-license-files.patch
new file mode 100644
index 0000000..90dedde
--- /dev/null
+++ b/patches/add-license-files.patch
@@ -0,0 +1,204 @@
+Add license files not present in the downloaded crates
+
+The Apache-2.0 and MIT licenses found here are from:
+
+https://github.com/awslabs/mls-rs/blob/main/LICENSE-apache
+https://github.com/awslabs/mls-rs/blob/main/LICENSE-mit
+
+diff --git a/LICENSE-apache b/LICENSE-apache
+new file mode 100644
+index 0000000..831fbc5
+--- /dev/null
++++ b/LICENSE-apache
+@@ -0,0 +1,176 @@
++                                 Apache License
++                           Version 2.0, January 2004
++                        http://www.apache.org/licenses/
++
++   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
++
++   1. Definitions.
++
++      "License" shall mean the terms and conditions for use, reproduction,
++      and distribution as defined by Sections 1 through 9 of this document.
++
++      "Licensor" shall mean the copyright owner or entity authorized by
++      the copyright owner that is granting the License.
++
++      "Legal Entity" shall mean the union of the acting entity and all
++      other entities that control, are controlled by, or are under common
++      control with that entity. For the purposes of this definition,
++      "control" means (i) the power, direct or indirect, to cause the
++      direction or management of such entity, whether by contract or
++      otherwise, or (ii) ownership of fifty percent (50%) or more of the
++      outstanding shares, or (iii) beneficial ownership of such entity.
++
++      "You" (or "Your") shall mean an individual or Legal Entity
++      exercising permissions granted by this License.
++
++      "Source" form shall mean the preferred form for making modifications,
++      including but not limited to software source code, documentation
++      source, and configuration files.
++
++      "Object" form shall mean any form resulting from mechanical
++      transformation or translation of a Source form, including but
++      not limited to compiled object code, generated documentation,
++      and conversions to other media types.
++
++      "Work" shall mean the work of authorship, whether in Source or
++      Object form, made available under the License, as indicated by a
++      copyright notice that is included in or attached to the work
++      (an example is provided in the Appendix below).
++
++      "Derivative Works" shall mean any work, whether in Source or Object
++      form, that is based on (or derived from) the Work and for which the
++      editorial revisions, annotations, elaborations, orother modifications
++      represent, as a whole, an original work of authorship. For the purposes
++      of this License, Derivative Works shall not include works that remain
++      separable from, or merely link (or bind by name) to the interfaces of,
++      the Work and Derivative Works thereof.
++
++      "Contribution" shall mean any work of authorship, including
++      the original version of the Work and any modifications or additions
++      to that Work or Derivative Works thereof, that is intentionally
++      submitted to Licensor for inclusion in the Work by the copyright owner
++      or by an individual or Legal Entity authorized to submit on behalf of
++      the copyright owner. For the purposes of this definition, "submitted"
++      means any form of electronic, verbal, or written communication sent
++      to the Licensor or its representatives, including but not limited to
++      communication on electronic mailing lists, source code control systems,
++      and issue tracking systems that are managed by, or on behalf of, the
++      Licensor for the purpose of discussing and improving the Work, but
++      excluding communication that is conspicuously marked or otherwise
++      designated in writing by the copyright owner as "Not a Contribution."
++
++      "Contributor" shall mean Licensor and any individual or Legal Entity
++      on behalf of whom a Contribution has been received by Licensor and
++      subsequently incorporated within the Work.
++
++   2. Grant of Copyright License. Subject to the terms and conditions of
++      this License, each Contributor hereby grants to You a perpetual,
++      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
++      copyright license to reproduce, prepare Derivative Works of,
++      publicly display, publicly perform, sublicense, and distribute the
++      Work and such Derivative Works in Source or Object form.
++
++   3. Grant of Patent License. Subject to the terms and conditions of
++      this License, each Contributor hereby grants to You a perpetual,
++      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
++      (except as stated in this section) patent license to make, have made,
++      use, offer to sell, sell, import, and otherwise transfer the Work,
++      where such license applies only to those patent claims licensable
++      by such Contributor that are necessarily infringed by their
++      Contribution(s) alone or by combination of their Contribution(s)
++      with the Work to which such Contribution(s) was submitted. If You
++      institute patent litigation against any entity (including a
++      cross-claim or counterclaim in a lawsuit) alleging that the Work
++      or a Contribution incorporated within the Work constitutes direct
++      or contributory patent infringement, then any patent licenses
++      granted to You under this License for that Work shall terminate
++      as of the date such litigation is filed.
++
++   4. Redistribution. You may reproduce and distribute copies of the
++      Work or Derivative Works thereof in any medium, with or without
++      modifications, and in Source or Object form, provided that You
++      meet the following conditions:
++
++      (a) You must give any other recipients of the Work or
++          Derivative Works a copy of this License; and
++
++      (b) You must cause any modified files to carry prominent notices
++          stating that You changed the files; and
++
++      (c) You must retain, in the Source form of any Derivative Works
++          that You distribute, all copyright, patent, trademark, and
++          attribution notices from the Source form of the Work,
++          excluding those notices that do not pertain to any part of
++          the Derivative Works; and
++
++      (d) If the Work includes a "NOTICE" text file as part of its
++          distribution, then any Derivative Works that You distribute must
++          include a readable copy of the attribution notices contained
++          within such NOTICE file, excluding those notices that do not
++          pertain to any part of the Derivative Works, in at least one
++          of the following places: within a NOTICE text file distributed
++          as part of the Derivative Works; within the Source form or
++          documentation, if provided along with the Derivative Works; or,
++          within a display generated by the Derivative Works, if and
++          wherever such third-party notices normally appear. The contents
++          of the NOTICE file are for informational purposes only and
++          do not modify the License. You may add Your own attribution
++          notices within Derivative Works that You distribute, alongside
++          or as an addendum to the NOTICE text from the Work, provided
++          that such additional attribution notices cannot be construed
++          as modifying the License.
++
++      You may add Your own copyright statement to Your modifications and
++      may provide additional or different license terms and conditions
++      for use, reproduction, or distribution of Your modifications, or
++      for any such Derivative Works as a whole, provided Your use,
++      reproduction, and distribution of the Work otherwise complies with
++      the conditions stated in this License.
++
++   5. Submission of Contributions. Unless You explicitly state otherwise,
++      any Contribution intentionally submitted for inclusion in the Work
++      by You to the Licensor shall be under the terms and conditions of
++      this License, without any additional terms or conditions.
++      Notwithstanding the above, nothing herein shall supersede or modify
++      the terms of any separate license agreement you may have executed
++      with Licensor regarding such Contributions.
++
++   6. Trademarks. This License does not grant permission to use the trade
++      names, trademarks, service marks, or product names of the Licensor,
++      except as required for reasonable and customary use in describing the
++      origin of the Work and reproducing the content of the NOTICE file.
++
++   7. Disclaimer of Warranty. Unless required by applicable law or
++      agreed to in writing, Licensor provides the Work (and each
++      Contributor provides its Contributions) on an "AS IS" BASIS,
++      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
++      implied, including, without limitation, any warranties or conditions
++      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
++      PARTICULAR PURPOSE. You are solely responsible for determining the
++      appropriateness of using or redistributing the Work and assume any
++      risks associated with Your exercise of permissions under this License.
++
++   8. Limitation of Liability. In no event and under no legal theory,
++      whether in tort (including negligence), contract, or otherwise,
++      unless required by applicable law (such as deliberate and grossly
++      negligent acts) or agreed to in writing, shall any Contributor be
++      liable to You for damages, including any direct, indirect, special,
++      incidental, or consequential damages of any character arising as a
++      result of this License or out of the use or inability to use the
++      Work (including but not limited to damages for loss of goodwill,
++      work stoppage, computer failure or malfunction, or any and all
++      other commercial damages or losses), even if such Contributor
++      has been advised of the possibility of such damages.
++
++   9. Accepting Warranty or Additional Liability. While redistributing
++      the Work or Derivative Works thereof, You may choose to offer,
++      and charge a fee for, acceptance of support, warranty, indemnity,
++      or other liability obligations and/or rights consistent with this
++      License. However, in accepting such obligations, You may act only
++      on Your own behalf and on Your sole responsibility, not on behalf
++      of any other Contributor, and only if You agree to indemnify,
++      defend, and hold each Contributor harmless for any liability
++      incurred by, or claims asserted against, such Contributor by reason
++      of your accepting any such warranty or additional liability.
++
++   END OF TERMS AND CONDITIONS
+diff --git a/LICENSE-mit b/LICENSE-mit
+new file mode 100644
+index 0000000..e547c4a
+--- /dev/null
++++ b/LICENSE-mit
+@@ -0,0 +1,9 @@
++MIT License
++
++Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
++
++Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including  without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to  the following conditions:
++
++The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
++
++THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN  NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/src/lib.rs b/src/lib.rs
index 3c7603f..593bd71 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,13 +2,17 @@
 // Copyright by contributors to this project.
 // SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
+use std::str::FromStr;
+
 use darling::{
     ast::{self, Fields},
     FromDeriveInput, FromField, FromVariant,
 };
-use proc_macro2::TokenStream;
+use proc_macro2::{Literal, TokenStream};
 use quote::quote;
-use syn::{parse_macro_input, parse_quote, DeriveInput, Expr, Generics, Ident, Index, Path};
+use syn::{
+    parse_macro_input, parse_quote, Attribute, DeriveInput, Expr, Generics, Ident, Index, Lit, Path,
+};
 
 enum Operation {
     Size,
@@ -84,8 +88,9 @@ struct MlsVariantReceiver {
 }
 
 #[derive(FromDeriveInput)]
-#[darling(attributes(mls_codec))]
+#[darling(attributes(mls_codec), forward_attrs(repr))]
 struct MlsInputReceiver {
+    attrs: Vec<Attribute>,
     ident: Ident,
     generics: Generics,
     data: ast::Data<MlsVariantReceiver, MlsFieldReceiver>,
@@ -95,28 +100,86 @@ impl MlsInputReceiver {
     fn handle_input(&self, operation: Operation) -> TokenStream {
         match self.data {
             ast::Data::Struct(ref s) => struct_impl(s, operation),
-            ast::Data::Enum(ref e) => enum_impl(&self.ident, e, operation),
+            ast::Data::Enum(ref e) => enum_impl(&self.ident, &self.attrs, e, operation),
         }
     }
 }
 
-fn enum_impl(ident: &Ident, variants: &[MlsVariantReceiver], operation: Operation) -> TokenStream {
+fn repr_ident(attrs: &[Attribute]) -> Option<Ident> {
+    let repr_path = attrs
+        .iter()
+        .filter(|attr| matches!(attr.style, syn::AttrStyle::Outer))
+        .find(|attr| attr.path().is_ident("repr"))
+        .map(|repr| repr.parse_args())
+        .transpose()
+        .ok()
+        .flatten();
+
+    let Some(Expr::Path(path)) = repr_path else {
+        return None;
+    };
+
+    path.path
+        .segments
+        .iter()
+        .find(|s| s.ident != "C")
+        .map(|path| path.ident.clone())
+}
+
+/// Provides the discriminant for a given variant. If the variant does not specify a suffix
+/// and a `repr_ident` is provided, it will be appended to number.
+fn discriminant_for_variant(
+    variant: &MlsVariantReceiver,
+    repr_ident: &Option<Ident>,
+) -> TokenStream {
+    let discriminant = variant
+        .discriminant
+        .clone()
+        .expect("Enum discriminants must be explicitly defined");
+
+    let Expr::Lit(lit_expr) = &discriminant else {
+        return quote! {#discriminant};
+    };
+
+    let Lit::Int(lit_int) = &lit_expr.lit else {
+        return quote! {#discriminant};
+    };
+
+    if lit_int.suffix().is_empty() {
+        // This is dirty and there is probably a better way of doing this but I'm way too much of a noob at
+        // proc macros to pull it off...
+        // TODO: Add proper support for correctly ignoring transparent, packed and modifiers
+        let str = format!(
+            "{}{}",
+            lit_int.base10_digits(),
+            &repr_ident.clone().expect("Expected a repr(u*) to be provided or for the variant's discriminant to be defined with suffixed literals.")
+        );
+        Literal::from_str(&str)
+            .map(|l| quote! {#l})
+            .ok()
+            .unwrap_or_else(|| quote! {#discriminant})
+    } else {
+        quote! {#discriminant}
+    }
+}
+
+fn enum_impl(
+    ident: &Ident,
+    attrs: &[Attribute],
+    variants: &[MlsVariantReceiver],
+    operation: Operation,
+) -> TokenStream {
     let handle_error = operation.is_result().then_some(quote! { ? });
     let path = operation.path();
     let call = operation.call();
     let extras = operation.extras();
     let enum_name = &ident;
-
+    let repr_ident = repr_ident(attrs);
     if matches!(operation, Operation::Decode) {
         let cases = variants.iter().map(|variant| {
             let variant_name = &variant.ident;
 
-            // TODO: Calculate discriminant and support integers that are assumed types like u16,
-            // u32 etc based on repr()
-            let discriminant = &variant
-                .discriminant
-                .clone()
-                .expect("Enum discriminants must be explicitly defined");
+            let discriminant = discriminant_for_variant(variant, &repr_ident);
 
             // TODO: Support more than 1 field
             match variant.fields.len() {
@@ -142,10 +205,7 @@ fn enum_impl(ident: &Ident, variants: &[MlsVariantReceiver], operation: Operatio
     let cases = variants.iter().map(|variant| {
         let variant_name = &variant.ident;
 
-        let discriminant = &variant
-            .discriminant
-            .clone()
-            .expect("Enum discriminants must be explicitly defined");
+        let discriminant = discriminant_for_variant(variant, &repr_ident);
 
         let (parameter, field) = if variant.fields.is_empty() {
             (None, None)
@@ -220,6 +280,7 @@ where
     F: FnOnce(&MlsInputReceiver) -> TokenStream,
 {
     let input = parse_macro_input!(input as DeriveInput);
+
     let input = MlsInputReceiver::from_derive_input(&input).unwrap();
 
     let name = &input.ident;