Allow testing a cranelift backend built into rustc itself

This avoids building cranelift twice in rust's CI and is a lot easier
than trying to make building of codegen backends work from within a
cargo invocation done by rust's build system.

3 files changed, 29 insertions, 17 deletions

diff --git a/scripts/cargo-clif.rs b/scripts/cargo-clif.rs
index 0d5d9f7db01..99b97be24e6 100644
--- a/scripts/cargo-clif.rs
+++ b/scripts/cargo-clif.rs
@@ -12,17 +12,21 @@ fn main() {
 
     let mut rustflags = String::new();
     rustflags.push_str(" -Cpanic=abort -Zpanic-abort-tests -Zcodegen-backend=");
-    rustflags.push_str(
-        sysroot
-            .join(if cfg!(windows) { "bin" } else { "lib" })
-            .join(
-                env::consts::DLL_PREFIX.to_string()
-                    + "rustc_codegen_cranelift"
-                    + env::consts::DLL_SUFFIX,
-            )
-            .to_str()
-            .unwrap(),
-    );
+    if let Some(name) = option_env!("BUILTIN_BACKEND") {
+        rustflags.push_str(name);
+    } else {
+        rustflags.push_str(
+            sysroot
+                .join(if cfg!(windows) { "bin" } else { "lib" })
+                .join(
+                    env::consts::DLL_PREFIX.to_string()
+                        + "rustc_codegen_cranelift"
+                        + env::consts::DLL_SUFFIX,
+                )
+                .to_str()
+                .unwrap(),
+        );
+    }
     rustflags.push_str(" --sysroot ");
     rustflags.push_str(sysroot.to_str().unwrap());
     env::set_var("RUSTFLAGS", env::var("RUSTFLAGS").unwrap_or(String::new()) + &rustflags);
diff --git a/scripts/rustc-clif.rs b/scripts/rustc-clif.rs
index df94b80b34f..33d51bdddea 100644
--- a/scripts/rustc-clif.rs
+++ b/scripts/rustc-clif.rs
@@ -19,9 +19,13 @@ fn main() {
     let mut args = vec![];
     args.push(OsString::from("-Cpanic=abort"));
     args.push(OsString::from("-Zpanic-abort-tests"));
-    let mut codegen_backend_arg = OsString::from("-Zcodegen-backend=");
-    codegen_backend_arg.push(cg_clif_dylib_path);
-    args.push(codegen_backend_arg);
+    if let Some(name) = option_env!("BUILTIN_BACKEND") {
+        args.push(OsString::from(format!("-Zcodegen-backend={name}")))
+    } else {
+        let mut codegen_backend_arg = OsString::from("-Zcodegen-backend=");
+        codegen_backend_arg.push(cg_clif_dylib_path);
+        args.push(codegen_backend_arg);
+    }
     if !passed_args.iter().any(|arg| {
         arg == "--sysroot" || arg.to_str().map(|s| s.starts_with("--sysroot=")) == Some(true)
     }) {
diff --git a/scripts/rustdoc-clif.rs b/scripts/rustdoc-clif.rs
index 36a00dc676e..10582cc7bb3 100644
--- a/scripts/rustdoc-clif.rs
+++ b/scripts/rustdoc-clif.rs
@@ -19,9 +19,13 @@ fn main() {
     let mut args = vec![];
     args.push(OsString::from("-Cpanic=abort"));
     args.push(OsString::from("-Zpanic-abort-tests"));
-    let mut codegen_backend_arg = OsString::from("-Zcodegen-backend=");
-    codegen_backend_arg.push(cg_clif_dylib_path);
-    args.push(codegen_backend_arg);
+    if let Some(name) = option_env!("BUILTIN_BACKEND") {
+        args.push(OsString::from(format!("-Zcodegen-backend={name}")))
+    } else {
+        let mut codegen_backend_arg = OsString::from("-Zcodegen-backend=");
+        codegen_backend_arg.push(cg_clif_dylib_path);
+        args.push(codegen_backend_arg);
+    }
     if !passed_args.iter().any(|arg| {
         arg == "--sysroot" || arg.to_str().map(|s| s.starts_with("--sysroot=")) == Some(true)
     }) {