Rollup merge of rust-lang#83820 - petrochenkov:nolinkargs, r=nagisa

Remove attribute `#[link_args]`

Closes rust-lang#29596

The attribute could always be replaced with `-C link-arg`, but cargo didn't provide a reasonable way to pass such flags to rustc.
Now cargo supports `cargo:rustc-link-arg*` directives in build scripts (https://doc.rust-lang.org/cargo/reference/unstable.html#extra-link-arg), so this attribute can be removed.

Author: Dylan-DPC

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1411,15 +1411,10 @@ fn add_link_script(cmd: &mut dyn Linker, sess: &Session, tmpdir: &Path, crate_ty
     }
 }
 
-/// Add arbitrary "user defined" args defined from command line and by `#[link_args]` attributes.
+/// Add arbitrary "user defined" args defined from command line.
 /// FIXME: Determine where exactly these args need to be inserted.
-fn add_user_defined_link_args(
-    cmd: &mut dyn Linker,
-    sess: &Session,
-    codegen_results: &CodegenResults,
-) {
+fn add_user_defined_link_args(cmd: &mut dyn Linker, sess: &Session) {
     cmd.args(&sess.opts.cg.link_args);
-    cmd.args(&*codegen_results.crate_info.link_args);
 }
 
 /// Add arbitrary "late link" args defined by the target spec.
@@ -1761,7 +1756,7 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>(
     add_rpath_args(cmd, sess, codegen_results, out_filename);
 
     // OBJECT-FILES-MAYBE, CUSTOMIZATION-POINT
-    add_user_defined_link_args(cmd, sess, codegen_results);
+    add_user_defined_link_args(cmd, sess);
 
     // NO-OPT-OUT, OBJECT-FILES-NO, AUDIT-ORDER
     cmd.finalize();

compiler/rustc_codegen_ssa/src/base.rs

@@ -754,7 +754,6 @@ impl CrateInfo {
             is_no_builtins: Default::default(),
             native_libraries: Default::default(),
             used_libraries: tcx.native_libraries(LOCAL_CRATE).iter().map(Into::into).collect(),
-            link_args: tcx.link_args(LOCAL_CRATE),
             crate_name: Default::default(),
             used_crates_dynamic: cstore::used_crates(tcx, LinkagePreference::RequireDynamic),
             used_crates_static: cstore::used_crates(tcx, LinkagePreference::RequireStatic),

compiler/rustc_codegen_ssa/src/lib.rs

@@ -139,7 +139,6 @@ pub struct CrateInfo {
     pub native_libraries: FxHashMap<CrateNum, Vec<NativeLib>>,
     pub crate_name: FxHashMap<CrateNum, String>,
     pub used_libraries: Vec<NativeLib>,
-    pub link_args: Lrc<Vec<String>>,
     pub used_crate_source: FxHashMap<CrateNum, Lrc<CrateSource>>,
     pub used_crates_static: Vec<(CrateNum, LibSource)>,
     pub used_crates_dynamic: Vec<(CrateNum, LibSource)>,

compiler/rustc_feature/src/active.rs

@@ -258,9 +258,6 @@ declare_features! (
     // feature-group-start: actual feature gates
     // -------------------------------------------------------------------------
 
-    /// Allows using the `#[link_args]` attribute.
-    (active, link_args, "1.0.0", Some(29596), None),
-
     /// Allows defining identifiers beyond ASCII.
     (active, non_ascii_idents, "1.0.0", Some(55467), None),
 

compiler/rustc_feature/src/builtin_attrs.rs

@@ -279,11 +279,6 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
 
     // Linking:
     gated!(naked, AssumedUsed, template!(Word), naked_functions, experimental!(naked)),
-    gated!(
-        link_args, Normal, template!(NameValueStr: "args"),
-        "the `link_args` attribute is experimental and not portable across platforms, \
-        it is recommended to use `#[link(name = \"foo\")] instead",
-    ),
     gated!(
         link_ordinal, AssumedUsed, template!(List: "ordinal"), raw_dylib,
         experimental!(link_ordinal)

compiler/rustc_feature/src/removed.rs

@@ -128,6 +128,10 @@ declare_features! (
     /// Allows comparing raw pointers during const eval.
     (removed, const_compare_raw_pointers, "1.46.0", Some(53020), None,
      Some("cannot be allowed in const eval in any meaningful way")),
+    /// Allows using the `#[link_args]` attribute.
+    (removed, link_args, "1.53.0", Some(29596), None,
+     Some("removed in favor of using `-C link-arg=ARG` on command line, \
+           which is available from cargo build scripts with `cargo:rustc-link-arg` now")),
 
     // -------------------------------------------------------------------------
     // feature-group-end: removed features

compiler/rustc_metadata/src/lib.rs

@@ -26,7 +26,6 @@ pub use rmeta::{provide, provide_extern};
 
 mod dependency_format;
 mod foreign_modules;
-mod link_args;
 mod native_libs;
 mod rmeta;
 

compiler/rustc_metadata/src/link_args.rs

@@ -1,6 +1,5 @@
 use crate::creader::{CStore, LoadedMacro};
 use crate::foreign_modules;
-use crate::link_args;
 use crate::native_libs;
 use crate::rmeta::{self, encoder};
 
@@ -295,10 +294,6 @@ pub fn provide(providers: &mut Providers) {
                 foreign_modules::collect(tcx).into_iter().map(|m| (m.def_id, m)).collect();
             Lrc::new(modules)
         },
-        link_args: |tcx, cnum| {
-            assert_eq!(cnum, LOCAL_CRATE);
-            Lrc::new(link_args::collect(tcx))
-        },
 
         // Returns a map from a sufficiently visible external item (i.e., an
         // external item that is visible from at least one local module) to a

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -1253,11 +1253,6 @@ rustc_queries! {
         desc { |tcx| "native_library_kind({})", tcx.def_path_str(def_id) }
     }
 
-    query link_args(_: CrateNum) -> Lrc<Vec<String>> {
-        eval_always
-        desc { "looking up link arguments for a crate" }
-    }
-
     /// Does lifetime resolution, but does not descend into trait items. This
     /// should only be used for resolving lifetimes of on trait definitions,
     /// and is used to avoid cycles. Importantly, `resolve_lifetimes` still visits