feat: Drop support for non-syroot proc macro ABIs

.github/workflows/ci.yaml

@@ -24,6 +24,9 @@ jobs:
     runs-on: ${{ matrix.os }}
     env:
       CC: deny_c
+      # we want to build r-a on stable to check that it keeps building on stable,
+      # but we also want to test our proc-macro-srv which depends on nightly features
+      RUSTC_BOOTSTRAP: 1
 
     strategy:
       fail-fast: false
@@ -50,15 +53,15 @@ jobs:
         run: sed -i '/\[profile.dev]/a opt-level=1' Cargo.toml
 
       - name: Compile (tests)
-        run: cargo test --no-run --locked
+        run: cargo test --no-run --locked  --features sysroot-abi
 
       # It's faster to `test` before `build` ¯\_(ツ)_/¯
       - name: Compile (rust-analyzer)
         if: matrix.os == 'ubuntu-latest'
-        run: cargo build --quiet
+        run: cargo build --quiet --features sysroot-abi
 
       - name: Test
-        run: cargo test -- --nocapture --quiet
+        run: cargo test --features sysroot-abi -- --nocapture --quiet
 
       - name: Run analysis-stats on rust-analyzer
         if: matrix.os == 'ubuntu-latest'

crates/proc-macro-srv-cli/Cargo.toml

@@ -10,6 +10,7 @@ rust-version.workspace = true
 
 [dependencies]
 proc-macro-srv.workspace = true
+proc-macro-api.workspace = true
 
 [features]
 sysroot-abi = ["proc-macro-srv/sysroot-abi"]

crates/proc-macro-srv/src/cli.rs → crates/proc-macro-srv-cli/src/lib.rs

@@ -3,10 +3,9 @@ use std::io;
 
 use proc_macro_api::msg::{self, Message};
 
-use crate::ProcMacroSrv;
-
+#[cfg(feature = "sysroot-abi")]
 pub fn run() -> io::Result<()> {
-    let mut srv = ProcMacroSrv::default();
+    let mut srv = proc_macro_srv::ProcMacroSrv::default();
     let mut buf = String::new();
 
     while let Some(req) = read_request(&mut buf)? {
@@ -24,6 +23,27 @@ pub fn run() -> io::Result<()> {
 
     Ok(())
 }
+#[cfg(not(feature = "sysroot-abi"))]
+pub fn run() -> io::Result<()> {
+    let mut buf = String::new();
+
+    while let Some(req) = read_request(&mut buf)? {
+        let res = match req {
+            msg::Request::ListMacros { .. } => {
+                msg::Response::ListMacros(Err("server is built without sysroot support".to_owned()))
+            }
+            msg::Request::ExpandMacro(..) => msg::Response::ExpandMacro(Err(msg::PanicMessage(
+                "server is built without sysroot support".to_owned(),
+            ))),
+            msg::Request::ApiVersionCheck {} => {
+                msg::Response::ApiVersionCheck(proc_macro_api::msg::CURRENT_API_VERSION)
+            }
+        };
+        write_response(res)?
+    }
+
+    Ok(())
+}
 
 fn read_request(buf: &mut String) -> io::Result<Option<msg::Request>> {
     msg::Request::read(&mut io::stdin().lock(), buf)

crates/proc-macro-srv-cli/src/main.rs

@@ -1,6 +1,5 @@
 //! A standalone binary for `proc-macro-srv`.
-
-use proc_macro_srv::cli;
+//! Driver for proc macro server
 
 fn main() -> std::io::Result<()> {
     let v = std::env::var("RUST_ANALYZER_INTERNALS_DO_NOT_USE");
@@ -15,5 +14,5 @@ fn main() -> std::io::Result<()> {
         }
     }
 
-    cli::run()
+    proc_macro_srv_cli::run()
 }