Merge #6820

6820: Pass the crate environment to proc macros r=jonas-schievink a=jonas-schievink

In theory, fixes https://github.com/rust-analyzer/rust-analyzer/issues/6696.

This seems to result in these obscure crashes for some reason:

```
thread '<unnamed>' panicked at 'called `Option::unwrap()` on a `None` value', /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/scoped_cell.rs:75:51
stack backtrace:
   0: rust_begin_unwind
             at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/std/src/panicking.rs:483
   1: core::panicking::panic_fmt
             at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/core/src/panicking.rs:85
   2: core::panicking::panic
             at /rustc/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/library/core/src/panicking.rs:50
   3: core::option::Option<T>::unwrap
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/option.rs:383
   4: proc_macro::bridge::scoped_cell::ScopedCell<T>::replace
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/scoped_cell.rs:75
   5: proc_macro::bridge::client::BridgeState::with::{{closure}}
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/client.rs:291
   6: std::thread::local::LocalKey<T>::try_with
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/thread/local.rs:272
   7: std::thread::local::LocalKey<T>::with
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/thread/local.rs:248
   8: proc_macro::bridge::client::BridgeState::with
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/client.rs:290
   9: proc_macro::bridge::client::<impl proc_macro::bridge::Bridge>::with
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/client.rs:329
  10: proc_macro::bridge::client::run_client::{{closure}}::{{closure}}
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/client.rs:375
  11: proc_macro::bridge::scoped_cell::ScopedCell<T>::set::{{closure}}
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/scoped_cell.rs:80
  12: proc_macro::bridge::scoped_cell::ScopedCell<T>::replace
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/scoped_cell.rs:75
  13: proc_macro::bridge::scoped_cell::ScopedCell<T>::set
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/scoped_cell.rs:80
  14: proc_macro::bridge::client::<impl proc_macro::bridge::Bridge>::enter::{{closure}}
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/client.rs:325
  15: std::thread::local::LocalKey<T>::try_with
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/thread/local.rs:272
  16: std::thread::local::LocalKey<T>::with
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/thread/local.rs:248
  17: proc_macro::bridge::client::<impl proc_macro::bridge::Bridge>::enter
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/client.rs:325
  18: proc_macro::bridge::client::run_client::{{closure}}
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/client.rs:370
  19: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panic.rs:308
  20: std::panicking::try::do_call
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:381
  21: __rust_try
  22: std::panicking::try
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:345
  23: std::panic::catch_unwind
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panic.rs:382
  24: proc_macro::bridge::client::run_client
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/client.rs:369
  25: proc_macro::bridge::client::Client<fn(proc_macro::TokenStream) .> proc_macro::TokenStream>::expand1::run
             at /home/jonas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/proc_macro/src/bridge/client.rs:410
  26: proc_macro_srv::proc_macro::bridge::server::run_server
  27: proc_macro_srv::dylib::Expander::expand
  28: proc_macro_srv::ProcMacroSrv::expand
  29: proc_macro_srv::cli::run
  30: rust_analyzer::main
```

Co-authored-by: Jonas Schievink <[email protected]>

2 files changed, 9 insertions, 3 deletions

diff --git a/crates/proc_macro_api/src/lib.rs b/crates/proc_macro_api/src/lib.rs
index 0d061fd53..2ea456fb0 100644
--- a/crates/proc_macro_api/src/lib.rs
+++ b/crates/proc_macro_api/src/lib.rs
@@ -16,7 +16,7 @@ use std::{
     sync::Arc,
 };
 
-use base_db::ProcMacro;
+use base_db::{Env, ProcMacro};
 use tt::{SmolStr, Subtree};
 
 use crate::process::{ProcMacroProcessSrv, ProcMacroProcessThread};
@@ -39,17 +39,19 @@ impl PartialEq for ProcMacroProcessExpander {
     }
 }
 
-impl tt::TokenExpander for ProcMacroProcessExpander {
+impl base_db::ProcMacroExpander for ProcMacroProcessExpander {
     fn expand(
         &self,
         subtree: &Subtree,
         attr: Option<&Subtree>,
+        env: &Env,
     ) -> Result<Subtree, tt::ExpansionError> {
         let task = ExpansionTask {
             macro_body: subtree.clone(),
             macro_name: self.name.to_string(),
             attributes: attr.cloned(),
             lib: self.dylib_path.to_path_buf(),
+            env: env.iter().map(|(k, v)| (k.to_string(), v.to_string())).collect(),
         };
 
         let result: ExpansionResult = self.process.send_task(msg::Request::ExpansionMacro(task))?;
@@ -90,7 +92,7 @@ impl ProcMacroClient {
                     ProcMacroKind::FuncLike => base_db::ProcMacroKind::FuncLike,
                     ProcMacroKind::Attr => base_db::ProcMacroKind::Attr,
                 };
-                let expander: Arc<dyn tt::TokenExpander> = Arc::new(ProcMacroProcessExpander {
+                let expander = Arc::new(ProcMacroProcessExpander {
                     process: self.process.clone(),
                     name: name.clone(),
                     dylib_path: dylib_path.into(),
diff --git a/crates/proc_macro_api/src/rpc.rs b/crates/proc_macro_api/src/rpc.rs
index b85f92eea..cf830b59f 100644
--- a/crates/proc_macro_api/src/rpc.rs
+++ b/crates/proc_macro_api/src/rpc.rs
@@ -51,6 +51,9 @@ pub struct ExpansionTask {
     pub attributes: Option<Subtree>,
 
     pub lib: PathBuf,
+
+    /// Environment variables to set during macro expansion.
+    pub env: Vec<(String, String)>,
 }
 
 #[derive(Clone, Eq, PartialEq, Debug, Default, Serialize, Deserialize)]
@@ -251,6 +254,7 @@ mod tests {
             macro_name: Default::default(),
             attributes: None,
             lib: Default::default(),
+            env: Default::default(),
         };
 
         let json = serde_json::to_string(&task).unwrap();