Stabilize the rustc-link-arg option

src/cargo/core/compiler/custom_build.rs

@@ -315,7 +315,6 @@ fn build_work(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoResult<Job> {
     paths::create_dir_all(&script_dir)?;
     paths::create_dir_all(&script_out_dir)?;
 
-    let extra_link_arg = cx.bcx.config.cli_unstable().extra_link_arg;
     let nightly_features_allowed = cx.bcx.config.nightly_features_allowed;
     let targets: Vec<Target> = unit.pkg.targets().to_vec();
     // Need a separate copy for the fresh closure.
@@ -427,7 +426,6 @@ fn build_work(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoResult<Job> {
             &pkg_descr,
             &script_out_dir,
             &script_out_dir,
-            extra_link_arg,
             nightly_features_allowed,
             &targets,
         )?;
@@ -455,7 +453,6 @@ fn build_work(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoResult<Job> {
                 &pkg_descr,
                 &prev_script_out_dir,
                 &script_out_dir,
-                extra_link_arg,
                 nightly_features_allowed,
                 &targets_fresh,
             )?,
@@ -508,7 +505,6 @@ impl BuildOutput {
         pkg_descr: &str,
         script_out_dir_when_generated: &Path,
         script_out_dir: &Path,
-        extra_link_arg: bool,
         nightly_features_allowed: bool,
         targets: &[Target],
     ) -> CargoResult<BuildOutput> {
@@ -519,7 +515,6 @@ impl BuildOutput {
             pkg_descr,
             script_out_dir_when_generated,
             script_out_dir,
-            extra_link_arg,
             nightly_features_allowed,
             targets,
         )
@@ -535,7 +530,6 @@ impl BuildOutput {
         pkg_descr: &str,
         script_out_dir_when_generated: &Path,
         script_out_dir: &Path,
-        extra_link_arg: bool,
         nightly_features_allowed: bool,
         targets: &[Target],
     ) -> CargoResult<BuildOutput> {
@@ -606,59 +600,47 @@ impl BuildOutput {
                     linker_args.push((LinkType::Cdylib, value))
                 }
                 "rustc-link-arg-bins" => {
-                    if extra_link_arg {
-                        if !targets.iter().any(|target| target.is_bin()) {
-                            bail!(
-                                "invalid instruction `cargo:{}` from {}\n\
-                                 The package {} does not have a bin target.",
-                                key,
-                                whence,
-                                pkg_descr
-                            );
-                        }
-                        linker_args.push((LinkType::Bin, value));
-                    } else {
-                        warnings.push(format!("cargo:{} requires -Zextra-link-arg flag", key));
+                    if !targets.iter().any(|target| target.is_bin()) {
+                        bail!(
+                            "invalid instruction `cargo:{}` from {}\n\
+                                The package {} does not have a bin target.",
+                            key,
+                            whence,
+                            pkg_descr
+                        );
                     }
+                    linker_args.push((LinkType::Bin, value));
                 }
                 "rustc-link-arg-bin" => {
-                    if extra_link_arg {
-                        let mut parts = value.splitn(2, '=');
-                        let bin_name = parts.next().unwrap().to_string();
-                        let arg = parts.next().ok_or_else(|| {
-                            anyhow::format_err!(
-                                "invalid instruction `cargo:{}={}` from {}\n\
-                                 The instruction should have the form cargo:{}=BIN=ARG",
-                                key,
-                                value,
-                                whence,
-                                key
-                            )
-                        })?;
-                        if !targets
-                            .iter()
-                            .any(|target| target.is_bin() && target.name() == bin_name)
-                        {
-                            bail!(
-                                "invalid instruction `cargo:{}` from {}\n\
-                                 The package {} does not have a bin target with the name `{}`.",
-                                key,
-                                whence,
-                                pkg_descr,
-                                bin_name
-                            );
-                        }
-                        linker_args.push((LinkType::SingleBin(bin_name), arg.to_string()));
-                    } else {
-                        warnings.push(format!("cargo:{} requires -Zextra-link-arg flag", key));
+                    let mut parts = value.splitn(2, '=');
+                    let bin_name = parts.next().unwrap().to_string();
+                    let arg = parts.next().ok_or_else(|| {
+                        anyhow::format_err!(
+                            "invalid instruction `cargo:{}={}` from {}\n\
+                                The instruction should have the form cargo:{}=BIN=ARG",
+                            key,
+                            value,
+                            whence,
+                            key
+                        )
+                    })?;
+                    if !targets
+                        .iter()
+                        .any(|target| target.is_bin() && target.name() == bin_name)
+                    {
+                        bail!(
+                            "invalid instruction `cargo:{}` from {}\n\
+                                The package {} does not have a bin target with the name `{}`.",
+                            key,
+                            whence,
+                            pkg_descr,
+                            bin_name
+                        );
                     }
+                    linker_args.push((LinkType::SingleBin(bin_name), arg.to_string()));
                 }
                 "rustc-link-arg" => {
-                    if extra_link_arg {
-                        linker_args.push((LinkType::All, value));
-                    } else {
-                        warnings.push(format!("cargo:{} requires -Zextra-link-arg flag", key));
-                    }
+                    linker_args.push((LinkType::All, value));
                 }
                 "rustc-cfg" => cfgs.push(value.to_string()),
                 "rustc-env" => {
@@ -953,16 +935,13 @@ fn prev_build_output(cx: &mut Context<'_, '_>, unit: &Unit) -> (Option<BuildOutp
         .and_then(|bytes| paths::bytes2path(&bytes))
         .unwrap_or_else(|_| script_out_dir.clone());
 
-    let extra_link_arg = cx.bcx.config.cli_unstable().extra_link_arg;
-
     (
         BuildOutput::parse_file(
             &output_file,
             unit.pkg.library().map(|t| t.crate_name()),
             &unit.pkg.to_string(),
             &prev_script_out_dir,
             &script_out_dir,
-            extra_link_arg,
             cx.bcx.config.nightly_features_allowed,
             unit.pkg.targets(),
         )

src/cargo/core/features.rs

@@ -633,7 +633,6 @@ unstable_cli_options!(
     doctest_xcompile: bool = ("Compile and run doctests for non-host target using runner config"),
     dual_proc_macros: bool = ("Build proc-macros for both the host and the target"),
     future_incompat_report: bool = ("Enable creation of a future-incompat report for all dependencies"),
-    extra_link_arg: bool = ("Allow `cargo:rustc-link-arg` in build scripts"),
     features: Option<Vec<String>>  = (HIDDEN),
     jobserver_per_rustc: bool = (HIDDEN),
     minimal_versions: bool = ("Resolve minimal dependency versions instead of maximum"),
@@ -689,6 +688,9 @@ const STABILIZED_FEATURES: &str = "The new feature resolver is now available \
     See https://doc.rust-lang.org/nightly/cargo/reference/features.html#feature-resolver-version-2 \
     for more information.";
 
+const STABILIZED_EXTRA_LINK_ARG: &str = "Additional linker arguments are now \
+    supported without passing this flag.";
+
 fn deserialize_build_std<'de, D>(deserializer: D) -> Result<Option<Vec<String>>, D::Error>
 where
     D: serde::Deserializer<'de>,
@@ -859,7 +861,6 @@ impl CliUnstable {
             "terminal-width" => self.terminal_width = Some(parse_usize_opt(v)?),
             "namespaced-features" => self.namespaced_features = parse_empty(k, v)?,
             "weak-dep-features" => self.weak_dep_features = parse_empty(k, v)?,
-            "extra-link-arg" => self.extra_link_arg = parse_empty(k, v)?,
             "credential-process" => self.credential_process = parse_empty(k, v)?,
             "skip-rustdoc-fingerprint" => self.skip_rustdoc_fingerprint = parse_empty(k, v)?,
             "compile-progress" => stabilized_warn(k, "1.30", STABILIZED_COMPILE_PROGRESS),
@@ -869,6 +870,7 @@ impl CliUnstable {
             "config-profile" => stabilized_warn(k, "1.43", STABILIZED_CONFIG_PROFILE),
             "crate-versions" => stabilized_warn(k, "1.47", STABILIZED_CRATE_VERSIONS),
             "package-features" => stabilized_warn(k, "1.51", STABILIZED_PACKAGE_FEATURES),
+            "extra-link-arg" => stabilized_warn(k, "1.56", STABILIZED_EXTRA_LINK_ARG),
             "future-incompat-report" => self.future_incompat_report = parse_empty(k, v)?,
             _ => bail!("unknown `-Z` flag specified: {}", k),
         }

src/cargo/util/config/target.rs

@@ -121,7 +121,7 @@ fn load_config_table(config: &Config, prefix: &str) -> CargoResult<TargetConfig>
     // Links do not support environment variables.
     let target_key = ConfigKey::from_str(prefix);
     let links_overrides = match config.get_table(&target_key)? {
-        Some(links) => parse_links_overrides(&target_key, links.val, config)?,
+        Some(links) => parse_links_overrides(&target_key, links.val)?,
         None => BTreeMap::new(),
     };
     Ok(TargetConfig {
@@ -135,10 +135,7 @@ fn load_config_table(config: &Config, prefix: &str) -> CargoResult<TargetConfig>
 fn parse_links_overrides(
     target_key: &ConfigKey,
     links: HashMap<String, CV>,
-    config: &Config,
 ) -> CargoResult<BTreeMap<String, BuildOutput>> {
-    let extra_link_arg = config.cli_unstable().extra_link_arg;
-
     let mut links_overrides = BTreeMap::new();
     for (lib_name, value) in links {
         // Skip these keys, it shares the namespace with `TargetConfig`.
@@ -182,28 +179,14 @@ fn parse_links_overrides(
                     output.linker_args.extend(args);
                 }
                 "rustc-link-arg-bins" => {
-                    if extra_link_arg {
-                        let args = value.list(key)?;
-                        let args = args.iter().map(|v| (LinkType::Bin, v.0.clone()));
-                        output.linker_args.extend(args);
-                    } else {
-                        config.shell().warn(format!(
-                            "target config `{}.{}` requires -Zextra-link-arg flag",
-                            target_key, key
-                        ))?;
-                    }
+                    let args = value.list(key)?;
+                    let args = args.iter().map(|v| (LinkType::Bin, v.0.clone()));
+                    output.linker_args.extend(args);
                 }
                 "rustc-link-arg" => {
-                    if extra_link_arg {
-                        let args = value.list(key)?;
-                        let args = args.iter().map(|v| (LinkType::All, v.0.clone()));
-                        output.linker_args.extend(args);
-                    } else {
-                        config.shell().warn(format!(
-                            "target config `{}.{}` requires -Zextra-link-arg flag",
-                            target_key, key
-                        ))?;
-                    }
+                    let args = value.list(key)?;
+                    let args = args.iter().map(|v| (LinkType::All, v.0.clone()));
+                    output.linker_args.extend(args);
                 }
                 "rustc-cfg" => {
                     let list = value.list(key)?;

src/doc/src/reference/build-scripts.md

@@ -94,6 +94,12 @@ one detailed below.
   re-run the script.
 * [`cargo:rerun-if-env-changed=VAR`](#rerun-if-env-changed) — Tells Cargo when
   to re-run the script.
+* [`cargo:rustc-link-arg=FLAG`](#rustc-link-arg) – Passes custom flags to a
+  linker for benchmarks, binaries, `cdylib` crates, examples, and tests.
+* [`cargo:rustc-link-arg-bin=BIN=FLAG`](#rustc-link-arg-bin) – Passes custom
+  flags to a linker for the binary `BIN`.
+* [`cargo:rustc-link-arg-bins=FLAG`](#rustc-link-arg-bins) – Passes custom
+  flags to a linker for binaries.
 * [`cargo:rustc-link-lib=[KIND=]NAME`](#rustc-link-lib) — Adds a library to
   link.
 * [`cargo:rustc-link-search=[KIND=]PATH`](#rustc-link-search) — Adds to the
@@ -110,6 +116,38 @@ one detailed below.
 * [`cargo:KEY=VALUE`](#the-links-manifest-key) — Metadata, used by `links`
   scripts.
 
+
+<a id="rustc-link-arg"></a>
+#### `cargo:rustc-link-arg=FLAG`
+
+The `rustc-link-arg` instruction tells Cargo to pass the [`-C link-arg=FLAG`
+option][link-arg] to the compiler, but only when building supported targets
+(benchmarks, binaries, `cdylib` crates, examples, and tests). Its usage is
+highly platform specific. It is useful to set the shared library version or
+linker script.
+
+[link-arg]: ../../rustc/codegen-options/index.md#link-arg
+
+<a id="rustc-link-arg-bin"></a>
+#### `cargo:rustc-link-arg-bin=BIN=FLAG`
+
+The `rustc-link-arg-bin` instruction tells Cargo to pass the [`-C
+link-arg=FLAG` option][link-arg] to the compiler, but only when building
+the binary target with name `BIN`. Its usage is highly platform specific. It is useful
+to set a linker script or other linker options.
+
+[link-arg]: ../../rustc/codegen-options/index.md#link-arg
+
+<a id="rustc-link-arg-bins"></a>
+#### `cargo:rustc-link-arg-bins=FLAG`
+
+The `rustc-link-arg-bins` instruction tells Cargo to pass the [`-C
+link-arg=FLAG` option][link-arg] to the compiler, but only when building a
+binary target. Its usage is highly platform specific. It is useful
+to set a linker script or other linker options.
+
+[link-arg]: ../../rustc/codegen-options/index.md#link-arg
+
 <a id="rustc-link-lib"></a>
 #### `cargo:rustc-link-lib=[KIND=]NAME`
 

src/doc/src/reference/unstable.md

@@ -63,7 +63,6 @@ Each new feature described below should explain how to use it.
 * Unstable-specific features
     * [-Z allow-features](#allow-features) — Provides a way to restrict which unstable features are used.
 * Build scripts and linking
-    * [extra-link-arg](#extra-link-arg) — Allows build scripts to pass extra link arguments in more cases.
     * [Metabuild](#metabuild) — Provides declarative build scripts.
 * Resolver and features
     * [no-index-update](#no-index-update) — Prevents cargo from updating the index cache.
@@ -133,51 +132,6 @@ to any Rust tools that cargo ends up calling (like `rustc` or
 `rustdoc`). Thus, if you run `cargo -Zallow-features=`, no unstable
 Cargo _or_ Rust features can be used.
 
-### extra-link-arg
-* Tracking Issue: [#9426](https://github.com/rust-lang/cargo/issues/9426)
-* Original Pull Request: [#7811](https://github.com/rust-lang/cargo/pull/7811)
-
-The `-Z extra-link-arg` flag makes the following instructions available
-in build scripts:
-
-* [`cargo:rustc-link-arg-bins=FLAG`](#rustc-link-arg-bins) – Passes custom
-  flags to a linker for binaries.
-* [`cargo:rustc-link-arg-bin=BIN=FLAG`](#rustc-link-arg-bin) – Passes custom
-  flags to a linker for the binary `BIN`.
-* [`cargo:rustc-link-arg=FLAG`](#rustc-link-arg) – Passes custom flags to a
-  linker for benchmarks, binaries, `cdylib` crates, examples, and tests.
-
-<a id="rustc-link-arg-bins"></a>
-#### `cargo:rustc-link-arg-bins=FLAG`
-
-The `rustc-link-arg-bins` instruction tells Cargo to pass the [`-C
-link-arg=FLAG` option][link-arg] to the compiler, but only when building a
-binary target. Its usage is highly platform specific. It is useful
-to set a linker script or other linker options.
-
-[link-arg]: ../../rustc/codegen-options/index.md#link-arg
-
-<a id="rustc-link-arg-bin"></a>
-#### `cargo:rustc-link-arg-bin=BIN=FLAG`
-
-The `rustc-link-arg-bin` instruction tells Cargo to pass the [`-C
-link-arg=FLAG` option][link-arg] to the compiler, but only when building
-the binary target with name `BIN`. Its usage is highly platform specific. It is useful
-to set a linker script or other linker options.
-
-[link-arg]: ../../rustc/codegen-options/index.md#link-arg
-
-<a id="rustc-link-arg"></a>
-#### `cargo:rustc-link-arg=FLAG`
-
-The `rustc-link-arg` instruction tells Cargo to pass the [`-C link-arg=FLAG`
-option][link-arg] to the compiler, but only when building supported targets
-(benchmarks, binaries, `cdylib` crates, examples, and tests). Its usage is
-highly platform specific. It is useful to set the shared library version or
-linker script.
-
-[link-arg]: ../../rustc/codegen-options/index.md#link-arg
-
 ### no-index-update
 * Original Issue: [#3479](https://github.com/rust-lang/cargo/issues/3479)
 * Tracking Issue: [#7404](https://github.com/rust-lang/cargo/issues/7404)
@@ -1479,3 +1433,10 @@ for more information on using the features CLI options.
 The `resolver` feature in `Cargo.toml` has been stabilized in the 1.51 release.
 See the [resolver versions](resolver.md#resolver-versions) for more
 information about specifying resolvers.
+
+### extra-link-arg
+
+The `extra-link-arg` feature to specify additional linker arguments in build
+scripts has been stabilized in the 1.56 release. See the [build script
+documentation](build-scripts.md#outputs-of-the-build-script) for more
+information on specifying extra linker arguments.