Allow LinkType to access the Target for checking if it applies.

Author: Dirbaio

src/cargo/core/compiler/custom_build.rs

@@ -25,7 +25,7 @@ pub struct BuildOutput {
     /// Names and link kinds of libraries, suitable for the `-l` flag.
     pub library_links: Vec<String>,
     /// Linker arguments suitable to be passed to `-C link-arg=<args>`
-    pub linker_args: Vec<(Option<LinkType>, String)>,
+    pub linker_args: Vec<(LinkType, String)>,
     /// Various `--cfg` flags to pass to the compiler.
     pub cfgs: Vec<String>,
     /// Additional environment variables to run the compiler with.
@@ -562,18 +562,18 @@ impl BuildOutput {
                 "rustc-link-lib" => library_links.push(value.to_string()),
                 "rustc-link-search" => library_paths.push(PathBuf::from(value)),
                 "rustc-link-arg-cdylib" | "rustc-cdylib-link-arg" => {
-                    linker_args.push((Some(LinkType::Cdylib), value))
+                    linker_args.push((LinkType::Cdylib, value))
                 }
                 "rustc-link-arg-bins" => {
                     if extra_link_arg {
-                        linker_args.push((Some(LinkType::Bin), value));
+                        linker_args.push((LinkType::Bin, value));
                     } else {
                         warnings.push(format!("cargo:{} requires -Zextra-link-arg flag", key));
                     }
                 }
                 "rustc-link-arg" => {
                     if extra_link_arg {
-                        linker_args.push((None, value));
+                        linker_args.push((LinkType::All, value));
                     } else {
                         warnings.push(format!("cargo:{} requires -Zextra-link-arg flag", key));
                     }

src/cargo/core/compiler/mod.rs

@@ -64,27 +64,23 @@ const RUSTDOC_CRATE_VERSION_FLAG: &str = "--crate-version";
 
 #[derive(Copy, Clone, Hash, Debug, PartialEq, Eq)]
 pub enum LinkType {
+    All,
     Cdylib,
     Bin,
     Test,
     Bench,
     Example,
 }
 
-impl From<&super::Target> for Option<LinkType> {
-    fn from(value: &super::Target) -> Self {
-        if value.is_cdylib() {
-            Some(LinkType::Cdylib)
-        } else if value.is_bin() {
-            Some(LinkType::Bin)
-        } else if value.is_test() {
-            Some(LinkType::Test)
-        } else if value.is_bench() {
-            Some(LinkType::Bench)
-        } else if value.is_exe_example() {
-            Some(LinkType::Example)
-        } else {
-            None
+impl LinkType {
+    pub fn applies_to(&self, target: &Target) -> bool {
+        match self {
+            LinkType::All => true,
+            LinkType::Cdylib => target.is_cdylib(),
+            LinkType::Bin => target.is_bin(),
+            LinkType::Test => target.is_test(),
+            LinkType::Bench => target.is_bench(),
+            LinkType::Example => target.is_exe_example(),
         }
     }
 }
@@ -227,7 +223,6 @@ fn rustc(cx: &mut Context<'_, '_>, unit: &Unit, exec: &Arc<dyn Executor>) -> Car
     // If we are a binary and the package also contains a library, then we
     // don't pass the `-l` flags.
     let pass_l_flag = unit.target.is_lib() || !unit.pkg.targets().iter().any(|t| t.is_lib());
-    let link_type = (&unit.target).into();
 
     let dep_info_name = if cx.files().use_extra_filename(unit) {
         format!(
@@ -280,7 +275,7 @@ fn rustc(cx: &mut Context<'_, '_>, unit: &Unit, exec: &Arc<dyn Executor>) -> Car
                     &script_outputs,
                     &build_scripts,
                     pass_l_flag,
-                    link_type,
+                    &target,
                     current_id,
                 )?;
                 add_plugin_deps(&mut rustc, &script_outputs, &build_scripts, &root_output)?;
@@ -371,7 +366,7 @@ fn rustc(cx: &mut Context<'_, '_>, unit: &Unit, exec: &Arc<dyn Executor>) -> Car
         build_script_outputs: &BuildScriptOutputs,
         build_scripts: &BuildScripts,
         pass_l_flag: bool,
-        link_type: Option<LinkType>,
+        target: &Target,
         current_id: PackageId,
     ) -> CargoResult<()> {
         for key in build_scripts.to_link.iter() {
@@ -396,11 +391,9 @@ fn rustc(cx: &mut Context<'_, '_>, unit: &Unit, exec: &Arc<dyn Executor>) -> Car
                 }
             }
 
-            if link_type.is_some() {
-                for (lt, arg) in &output.linker_args {
-                    if lt.is_none() || *lt == link_type {
-                        rustc.arg("-C").arg(format!("link-arg={}", arg));
-                    }
+            for (lt, arg) in &output.linker_args {
+                if lt.applies_to(&target) {
+                    rustc.arg("-C").arg(format!("link-arg={}", arg));
                 }
             }
         }

src/cargo/util/config/target.rs

@@ -134,13 +134,13 @@ fn parse_links_overrides(
                 }
                 "rustc-link-arg-cdylib" | "rustc-cdylib-link-arg" => {
                     let args = value.list(key)?;
-                    let args = args.iter().map(|v| (Some(LinkType::Cdylib), v.0.clone()));
+                    let args = args.iter().map(|v| (LinkType::Cdylib, v.0.clone()));
                     output.linker_args.extend(args);
                 }
                 "rustc-link-arg-bins" => {
                     if extra_link_arg {
                         let args = value.list(key)?;
-                        let args = args.iter().map(|v| (Some(LinkType::Bin), v.0.clone()));
+                        let args = args.iter().map(|v| (LinkType::Bin, v.0.clone()));
                         output.linker_args.extend(args);
                     } else {
                         config.shell().warn(format!(
@@ -152,7 +152,7 @@ fn parse_links_overrides(
                 "rustc-link-arg" => {
                     if extra_link_arg {
                         let args = value.list(key)?;
-                        let args = args.iter().map(|v| (None, v.0.clone()));
+                        let args = args.iter().map(|v| (LinkType::All, v.0.clone()));
                         output.linker_args.extend(args);
                     } else {
                         config.shell().warn(format!(