1 //! Procedural macros are implemented by compiling the macro providing crate
2 //! to a dynamic library with a particular ABI which the compiler uses to expand
3 //! macros. Unfortunately this ABI is not specified and can change from version
4 //! to version of the compiler. To support this we copy the ABI from the rust
5 //! compiler into submodules of this module (e.g proc_macro_srv::abis::abi_1_47).
7 //! All of these ABIs are subsumed in the `Abi` enum, which exposes a simple
8 //! interface the rest of rust analyzer can use to talk to the macro
11 //! # Adding a new ABI
13 //! To add a new ABI you'll need to copy the source of the target proc_macro
14 //! crate from the source tree of the Rust compiler into this directory tree.
15 //! Then you'll need to modify it
16 //! - Remove any feature! or other things which won't compile on stable
17 //! - change any absolute imports to relative imports within the ABI tree
19 //! Then you'll need to add a branch to the `Abi` enum and an implementation of
20 //! `Abi::expand`, `Abi::list_macros` and `Abi::from_lib` for the new ABI. See
21 //! `proc_macro_srv/src/abis/abi_1_47/mod.rs` for an example. Finally you'll
22 //! need to update the conditionals in `Abi::from_lib` to return your new ABI
23 //! for the relevant versions of the rust compiler
29 #[cfg(feature = "sysroot-abi")]
33 include!(concat!(env!("OUT_DIR"), "/rustc_version.rs"));
35 // Used by `test/utils.rs`
37 pub(crate) use abi_1_64::TokenStream as TestTokenStream;
39 use super::dylib::LoadProcMacroDylibError;
40 pub(crate) use abi_1_58::Abi as Abi_1_58;
41 pub(crate) use abi_1_63::Abi as Abi_1_63;
42 pub(crate) use abi_1_64::Abi as Abi_1_64;
43 #[cfg(feature = "sysroot-abi")]
44 pub(crate) use abi_sysroot::Abi as Abi_Sysroot;
45 use libloading::Library;
46 use proc_macro_api::{ProcMacroKind, RustCInfo};
48 pub struct PanicMessage {
49 message: Option<String>,
53 pub fn as_str(&self) -> Option<String> {
62 #[cfg(feature = "sysroot-abi")]
63 AbiSysroot(Abi_Sysroot),
71 /// *`lib` - The dynamic library containing the macro implementations
72 /// *`symbol_name` - The symbol name the macros can be found attributes
73 /// *`info` - RustCInfo about the compiler that was used to compile the
74 /// macro crate. This is the information we use to figure out
75 /// which ABI to return
80 #[cfg_attr(not(feature = "sysroot-abi"), allow(unused_variables))] version_string: String,
81 ) -> Result<Abi, LoadProcMacroDylibError> {
82 // the sysroot ABI relies on `extern proc_macro` with unstable features,
83 // instead of a snapshot of the proc macro bridge's source code. it's only
84 // enabled if we have an exact version match.
85 #[cfg(feature = "sysroot-abi")]
87 if version_string == RUSTC_VERSION_STRING {
88 let inner = unsafe { Abi_Sysroot::from_lib(lib, symbol_name) }?;
89 return Ok(Abi::AbiSysroot(inner));
92 // if we reached this point, versions didn't match. in testing, we
93 // want that to panic - this could mean that the format of `rustc
94 // --version` no longer matches the format of the version string
95 // stored in the `.rustc` section, and we want to catch that in-tree
99 let allow_mismatch = std::env::var("PROC_MACRO_SRV_ALLOW_SYSROOT_MISMATCH");
100 if let Ok("1") = allow_mismatch.as_deref() {
101 // only used by rust-analyzer developers, when working on the
102 // sysroot ABI from the rust-analyzer repository - which should
103 // only happen pre-subtree. this can be removed later.
106 "sysroot ABI mismatch: dylib rustc version (read from .rustc section): {:?} != proc-macro-srv version (read from 'rustc --version'): {:?}",
107 version_string, RUSTC_VERSION_STRING
113 // FIXME: this should use exclusive ranges when they're stable
114 // https://github.com/rust-lang/rust/issues/37854
115 match (info.version.0, info.version.1) {
117 let inner = unsafe { Abi_1_58::from_lib(lib, symbol_name) }?;
118 Ok(Abi::Abi1_58(inner))
121 let inner = unsafe { Abi_1_63::from_lib(lib, symbol_name) }?;
122 Ok(Abi::Abi1_63(inner))
125 let inner = unsafe { Abi_1_64::from_lib(lib, symbol_name) }?;
126 Ok(Abi::Abi1_64(inner))
128 _ => Err(LoadProcMacroDylibError::UnsupportedABI),
135 macro_body: &tt::Subtree,
136 attributes: Option<&tt::Subtree>,
137 ) -> Result<tt::Subtree, PanicMessage> {
139 Self::Abi1_58(abi) => abi.expand(macro_name, macro_body, attributes),
140 Self::Abi1_63(abi) => abi.expand(macro_name, macro_body, attributes),
141 Self::Abi1_64(abi) => abi.expand(macro_name, macro_body, attributes),
142 #[cfg(feature = "sysroot-abi")]
143 Self::AbiSysroot(abi) => abi.expand(macro_name, macro_body, attributes),
147 pub fn list_macros(&self) -> Vec<(String, ProcMacroKind)> {
149 Self::Abi1_58(abi) => abi.list_macros(),
150 Self::Abi1_63(abi) => abi.list_macros(),
151 Self::Abi1_64(abi) => abi.list_macros(),
152 #[cfg(feature = "sysroot-abi")]
153 Self::AbiSysroot(abi) => abi.list_macros(),