Do not use force-always-assert in xtask install by default

But add a flag to do so.

src/tools/rust-analyzer/xtask/src/flags.rs

@@ -49,6 +49,9 @@ xflags::xflags! {
             /// build in release with debug info set to 2.
             optional --dev-rel
 
+            /// Make `never!()`, `always!()` etc. panic instead of just logging an error.
+            optional --force-always-assert
+
             /// Apply PGO optimizations
             optional --pgo pgo: PgoTrainingCrate
         }
@@ -124,6 +127,7 @@ pub struct Install {
     pub jemalloc: bool,
     pub proc_macro_server: bool,
     pub dev_rel: bool,
+    pub force_always_assert: bool,
     pub pgo: Option<PgoTrainingCrate>,
 }
 
@@ -300,7 +304,12 @@ impl Install {
         } else {
             Malloc::System
         };
-        Some(ServerOpt { malloc, dev_rel: self.dev_rel, pgo: self.pgo.clone() })
+        Some(ServerOpt {
+            malloc,
+            dev_rel: self.dev_rel,
+            pgo: self.pgo.clone(),
+            force_always_assert: self.force_always_assert,
+        })
     }
     pub(crate) fn proc_macro_server(&self) -> Option<ProcMacroServerOpt> {
         if !self.proc_macro_server {

src/tools/rust-analyzer/xtask/src/install.rs

@@ -39,6 +39,18 @@ pub(crate) struct ServerOpt {
     pub(crate) malloc: Malloc,
     pub(crate) dev_rel: bool,
     pub(crate) pgo: Option<PgoTrainingCrate>,
+    pub(crate) force_always_assert: bool,
+}
+
+impl ServerOpt {
+    fn to_features(&self) -> Vec<&'static str> {
+        let mut features = Vec::new();
+        features.extend(self.malloc.to_features());
+        if self.force_always_assert {
+            features.extend(["--features", "force-always-assert"]);
+        }
+        features
+    }
 }
 
 pub(crate) struct ProcMacroServerOpt {
@@ -136,7 +148,7 @@ fn install_client(sh: &Shell, client_opt: ClientOpt) -> anyhow::Result<()> {
 }
 
 fn install_server(sh: &Shell, opts: ServerOpt) -> anyhow::Result<()> {
-    let features = opts.malloc.to_features();
+    let features = &opts.to_features();
     let profile = if opts.dev_rel { "dev-rel" } else { "release" };
 
     let mut install_cmd = cmd!(
@@ -148,7 +160,7 @@ fn install_server(sh: &Shell, opts: ServerOpt) -> anyhow::Result<()> {
         let target = detect_target(sh);
         let build_cmd = cmd!(
             sh,
-            "cargo build --manifest-path ./crates/rust-analyzer/Cargo.toml --bin rust-analyzer --target {target} --profile={profile} --locked --features force-always-assert {features...}"
+            "cargo build --manifest-path ./crates/rust-analyzer/Cargo.toml --bin rust-analyzer --target {target} --profile={profile} --locked {features...}"
         );
 
         let profile = crate::pgo::gather_pgo_profile(sh, build_cmd, &target, train_crate)?;