-//! Procedural macros are implemented by compiling the macro providing crate

-//! to a dynamic library with a particular ABI which the compiler uses to expand

-//! macros. Unfortunately this ABI is not specified and can change from version

-//! to version of the compiler. To support this we copy the ABI from the rust

-//! compiler into submodules of this module (e.g proc_macro_srv::abis::abi_1_47).

-//!

-//! All of these ABIs are subsumed in the `Abi` enum, which exposes a simple

-//! interface the rest of rust-analyzer can use to talk to the macro

-//! provider.

-//!

-//! # Adding a new ABI

-//!

-//! To add a new ABI you'll need to copy the source of the target proc_macro

-//! crate from the source tree of the Rust compiler into this directory tree.

-//! Then you'll need to modify it

-//! - Remove any feature! or other things which won't compile on stable

-//! - change any absolute imports to relative imports within the ABI tree

-//!

-//! Then you'll need to add a branch to the `Abi` enum and an implementation of

-//! `Abi::expand`, `Abi::list_macros` and `Abi::from_lib` for the new ABI. See

-//! `proc_macro_srv/src/abis/abi_1_47/mod.rs` for an example. Finally you'll

-//! need to update the conditionals in `Abi::from_lib` to return your new ABI

-//! for the relevant versions of the rust compiler

-//!

-

-mod abi_1_63;

-#[cfg(feature = "sysroot-abi")]

-mod abi_sysroot;

-

-// see `build.rs`

-include!(concat!(env!("OUT_DIR"), "/rustc_version.rs"));

-

-// Used by `test/utils.rs`

-#[cfg(all(test, feature = "sysroot-abi"))]

-pub(crate) use abi_sysroot::TokenStream as TestTokenStream;

-

-use super::dylib::LoadProcMacroDylibError;

-pub(crate) use abi_1_63::Abi as Abi_1_63;

-#[cfg(feature = "sysroot-abi")]

-pub(crate) use abi_sysroot::Abi as Abi_Sysroot;

-use libloading::Library;

-use proc_macro_api::{ProcMacroKind, RustCInfo};

-

-use crate::tt;

-

-pub struct PanicMessage {

- message: Option<String>,

-}

-

-impl PanicMessage {

- pub fn as_str(&self) -> Option<String> {

- self.message.clone()

- }

-}

-

-pub(crate) enum Abi {

- Abi1_63(Abi_1_63),

- #[cfg(feature = "sysroot-abi")]

- AbiSysroot(Abi_Sysroot),

-}

-

-impl Abi {

- /// Load a new ABI.

- ///

- /// # Arguments

- ///

- /// *`lib` - The dynamic library containing the macro implementations

- /// *`symbol_name` - The symbol name the macros can be found attributes

- /// *`info` - RustCInfo about the compiler that was used to compile the

- /// macro crate. This is the information we use to figure out

- /// which ABI to return

- pub fn from_lib(

- lib: &Library,

- symbol_name: String,

- info: RustCInfo,

- ) -> Result<Abi, LoadProcMacroDylibError> {

- // the sysroot ABI relies on `extern proc_macro` with unstable features,

- // instead of a snapshot of the proc macro bridge's source code. it's only

- // enabled if we have an exact version match.

- #[cfg(feature = "sysroot-abi")]

- {

- if info.version_string == RUSTC_VERSION_STRING {

- let inner = unsafe { Abi_Sysroot::from_lib(lib, symbol_name) }?;

- return Ok(Abi::AbiSysroot(inner));

- }

-

- // if we reached this point, versions didn't match. in testing, we

- // want that to panic - this could mean that the format of `rustc

- // --version` no longer matches the format of the version string

- // stored in the `.rustc` section, and we want to catch that in-tree

- // with `x.py test`

- #[cfg(test)]

- {

- let allow_mismatch = std::env::var("PROC_MACRO_SRV_ALLOW_SYSROOT_MISMATCH");

- if let Ok("1") = allow_mismatch.as_deref() {

- // only used by rust-analyzer developers, when working on the

- // sysroot ABI from the rust-analyzer repository - which should

- // only happen pre-subtree. this can be removed later.

- } else {

- panic!(

- "sysroot ABI mismatch: dylib rustc version (read from .rustc section): {:?} != proc-macro-srv version (read from 'rustc --version'): {:?}",

- info.version_string, RUSTC_VERSION_STRING

- );

- }

- }

- }

-

- // FIXME: this should use exclusive ranges when they're stable

- // https://github.com/rust-lang/rust/issues/37854

- match (info.version.0, info.version.1) {

- (1, 63) => {

- let inner = unsafe { Abi_1_63::from_lib(lib, symbol_name) }?;

- Ok(Abi::Abi1_63(inner))

- }

- _ => Err(LoadProcMacroDylibError::UnsupportedABI(info.version_string)),

- }

- }

-

- pub fn expand(

- &self,

- macro_name: &str,

- macro_body: &tt::Subtree,

- attributes: Option<&tt::Subtree>,

- ) -> Result<tt::Subtree, PanicMessage> {

- match self {

- Self::Abi1_63(abi) => abi.expand(macro_name, macro_body, attributes),

- #[cfg(feature = "sysroot-abi")]

- Self::AbiSysroot(abi) => abi.expand(macro_name, macro_body, attributes),

- }

- }

-

- pub fn list_macros(&self) -> Vec<(String, ProcMacroKind)> {

- match self {

- Self::Abi1_63(abi) => abi.list_macros(),

- #[cfg(feature = "sysroot-abi")]

- Self::AbiSysroot(abi) => abi.list_macros(),

- }

- }

-}

-

-#[test]

-fn test_version_check() {

- let path = paths::AbsPathBuf::assert(crate::proc_macro_test_dylib_path());

- let info = proc_macro_api::read_dylib_info(&path).unwrap();

- assert!(info.version.1 >= 50);

-}