rustc_session: Feature gate linker flavors for tier 3 targets

Author: petrochenkov

compiler/rustc_session/src/config.rs

@@ -12,7 +12,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 
 use rustc_data_structures::stable_hasher::{StableOrd, ToStableHashKey};
 use rustc_target::abi::Align;
-use rustc_target::spec::{PanicStrategy, SanitizerSet, SplitDebuginfo};
+use rustc_target::spec::{LinkerFlavorCli, PanicStrategy, SanitizerSet, SplitDebuginfo};
 use rustc_target::spec::{Target, TargetTriple, TargetWarnings, TARGETS};
 
 use crate::parse::{CrateCheckConfig, CrateConfig};
@@ -2525,6 +2525,19 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
         }
     }
 
+    if let Some(flavor) = cg.linker_flavor {
+        if matches!(flavor, LinkerFlavorCli::BpfLinker | LinkerFlavorCli::PtxLinker)
+            && !nightly_options::is_unstable_enabled(matches)
+        {
+            let msg = format!(
+                "linker flavor `{}` is unstable, `-Z unstable-options` \
+                 flag must also be passed to explicitly use it",
+                flavor.desc()
+            );
+            early_error(error_format, msg);
+        }
+    }
+
     let prints = collect_print_requests(&mut cg, &mut unstable_opts, matches, error_format);
 
     let cg = cg;

tests/ui/linkage-attr/unstable-flavor.bpf.stderr

@@ -0,0 +1,2 @@
+error: linker flavor `bpf-linker` is unstable, `-Z unstable-options` flag must also be passed to explicitly use it
+

tests/ui/linkage-attr/unstable-flavor.ptx.stderr

@@ -0,0 +1,2 @@
+error: linker flavor `ptx-linker` is unstable, `-Z unstable-options` flag must also be passed to explicitly use it
+

tests/ui/linkage-attr/unstable-flavor.rs

@@ -0,0 +1,10 @@
+// revisions: bpf ptx
+// [bpf] compile-flags: --target=bpfel-unknown-none -C linker-flavor=bpf-linker --crate-type=rlib
+// [bpf] error-pattern: linker flavor `bpf-linker` is unstable, `-Z unstable-options` flag
+// [bpf] needs-llvm-components:
+// [ptx] compile-flags: --target=nvptx64-nvidia-cuda -C linker-flavor=ptx-linker --crate-type=rlib
+// [ptx] error-pattern: linker flavor `ptx-linker` is unstable, `-Z unstable-options` flag
+// [ptx] needs-llvm-components:
+
+#![feature(no_core)]
+#![no_core]