| tag | 9e282d7b4af081df3f041f987a3686d461692a20 | |
|---|---|---|
| tagger | The Android Open Source Project <initial-contribution@android.com> | Mon Feb 05 11:37:57 2024 -0800 |
| object | bb91cbdf8391b15310ab56d10739f7a0f7ec5997 |
Android 14.0.0 Release 27 (UQ1A.240205.004.B1)
| commit | bb91cbdf8391b15310ab56d10739f7a0f7ec5997 | [log] [tgz] |
|---|---|---|
| author | Jeff Vander Stoep <jeffv@google.com> | Mon Apr 03 22:37:53 2023 +0000 |
| committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Mon Apr 03 22:37:53 2023 +0000 |
| tree | a363dd20440d28c7980f38dc9158414bb4dfbe57 | |
| parent | 7bf83716d717d8c0160446e6cc7fcd9fcd8dce0d [diff] | |
| parent | 704d77a60e7e2d73e78f30500f28fb5369314b37 [diff] |
Upgrade proc-macro2 to 1.0.54 am: 9ed73418c7 am: aae936a18a am: 2873cb66cf am: 704d77a60e Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/proc-macro2/+/2514439 Change-Id: I415ef5359cac6c2d1c28eb4f12d5fc615d76438b Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
A wrapper around the procedural macro API of the compiler's proc_macro crate. This library serves two purposes:
Bring proc-macro-like functionality to other contexts like build.rs and main.rs. Types from proc_macro are entirely specific to procedural macros and cannot ever exist in code outside of a procedural macro. Meanwhile proc_macro2 types may exist anywhere including non-macro code. By developing foundational libraries like syn and quote against proc_macro2 rather than proc_macro, the procedural macro ecosystem becomes easily applicable to many other use cases and we avoid reimplementing non-macro equivalents of those libraries.
Make procedural macros unit testable. As a consequence of being specific to procedural macros, nothing that uses proc_macro can be executed from a unit test. In order for helper libraries or components of a macro to be testable in isolation, they must be implemented using proc_macro2.
[dependencies] proc-macro2 = "1.0"
The skeleton of a typical procedural macro typically looks like this:
extern crate proc_macro; #[proc_macro_derive(MyDerive)] pub fn my_derive(input: proc_macro::TokenStream) -> proc_macro::TokenStream { let input = proc_macro2::TokenStream::from(input); let output: proc_macro2::TokenStream = { /* transform input */ }; proc_macro::TokenStream::from(output) }
If parsing with Syn, you'll use parse_macro_input! instead to propagate parse errors correctly back to the compiler when parsing fails.
The default feature set of proc-macro2 tracks the most recent stable compiler API. Functionality in proc_macro that is not yet stable is not exposed by proc-macro2 by default.
To opt into the additional APIs available in the most recent nightly compiler, the procmacro2_semver_exempt config flag must be passed to rustc. We will polyfill those nightly-only APIs back to Rust 1.31.0. As these are unstable APIs that track the nightly compiler, minor versions of proc-macro2 may make breaking changes to them at any time.
RUSTFLAGS='--cfg procmacro2_semver_exempt' cargo build
Note that this must not only be done for your crate, but for any crate that depends on your crate. This infectious nature is intentional, as it serves as a reminder that you are outside of the normal semver guarantees.
Semver exempt methods are marked as such in the proc-macro2 documentation.