linker: Add search_paths parameter to link_dylib_by_name

This allows for implementing looking up Meson and MinGW import
libraries.

See rust-lang#122455

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1280,8 +1280,9 @@ fn link_sanitizer_runtime(
         let filename = format!("rustc{channel}_rt.{name}");
         let path = find_sanitizer_runtime(sess, &filename);
         let rpath = path.to_str().expect("non-utf8 component in path");
+        let search_paths = SearchPaths::default();
         linker.args(&["-Wl,-rpath", "-Xlinker", rpath]);
-        linker.link_dylib_by_name(&filename, false, true);
+        linker.link_dylib_by_name(&filename, false, &search_paths, true);
     } else if sess.target.is_like_msvc && flavor == LinkerFlavor::Msvc(Lld::No) && name == "asan" {
         // MSVC provides the `/INFERASANLIBS` argument to automatically find the
         // compatible ASAN library.
@@ -2568,7 +2569,7 @@ fn add_native_libs_from_crate(
             }
             NativeLibKind::Dylib { as_needed } => {
                 if link_dynamic {
-                    cmd.link_dylib_by_name(name, verbatim, as_needed.unwrap_or(true))
+                    cmd.link_dylib_by_name(name, verbatim, search_paths, as_needed.unwrap_or(true))
                 }
             }
             NativeLibKind::Unspecified => {
@@ -2580,7 +2581,7 @@ fn add_native_libs_from_crate(
                     }
                 } else {
                     if link_dynamic {
-                        cmd.link_dylib_by_name(name, verbatim, true);
+                        cmd.link_dylib_by_name(name, verbatim, search_paths, true);
                     }
                 }
             }
@@ -2912,7 +2913,8 @@ fn add_dynamic_crate(cmd: &mut dyn Linker, sess: &Session, cratepath: &Path) {
     let stem = stem.unwrap().to_str().unwrap();
     // Convert library file-stem into a cc -l argument.
     let prefix = if stem.starts_with("lib") && !sess.target.is_like_windows { 3 } else { 0 };
-    cmd.link_dylib_by_name(&stem[prefix..], false, true);
+    let search_paths = SearchPaths::default();
+    cmd.link_dylib_by_name(&stem[prefix..], false, &search_paths, true);
 }
 
 fn relevant_lib(sess: &Session, lib: &NativeLib) -> bool {

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -167,7 +167,13 @@ pub fn get_linker<'a>(
 pub trait Linker {
     fn cmd(&mut self) -> &mut Command;
     fn set_output_kind(&mut self, output_kind: LinkOutputKind, out_filename: &Path);
-    fn link_dylib_by_name(&mut self, name: &str, verbatim: bool, as_needed: bool);
+    fn link_dylib_by_name(
+        &mut self,
+        name: &str,
+        verbatim: bool,
+        search_paths: &SearchPaths,
+        as_needed: bool,
+    );
     fn link_framework_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) {
         bug!("framework linked with unsupported linker")
     }
@@ -432,7 +438,13 @@ impl<'a> Linker for GccLinker<'a> {
         }
     }
 
-    fn link_dylib_by_name(&mut self, name: &str, verbatim: bool, as_needed: bool) {
+    fn link_dylib_by_name(
+        &mut self,
+        name: &str,
+        verbatim: bool,
+        _search_paths: &SearchPaths,
+        as_needed: bool,
+    ) {
         if self.sess.target.os == "illumos" && name == "c" {
             // libc will be added via late_link_args on illumos so that it will
             // appear last in the library search order.
@@ -807,7 +819,7 @@ impl<'a> Linker for MsvcLinker<'a> {
         }
     }
 
-    fn link_dylib_by_name(&mut self, name: &str, verbatim: bool, _as_needed: bool) {
+    fn link_dylib_by_name(&mut self, name: &str, verbatim: bool, _search_paths: &SearchPaths, _as_needed: bool) {
         self.cmd.arg(format!("{}{}", name, if verbatim { "" } else { ".lib" }));
     }
 
@@ -1051,7 +1063,13 @@ impl<'a> Linker for EmLinker<'a> {
 
     fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
 
-    fn link_dylib_by_name(&mut self, name: &str, _verbatim: bool, _as_needed: bool) {
+    fn link_dylib_by_name(
+        &mut self,
+        name: &str,
+        _verbatim: bool,
+        _search_paths: &SearchPaths,
+        _as_needed: bool,
+    ) {
         // Emscripten always links statically
         self.cmd.arg("-l").arg(name);
     }
@@ -1225,7 +1243,13 @@ impl<'a> Linker for WasmLd<'a> {
         }
     }
 
-    fn link_dylib_by_name(&mut self, name: &str, _verbatim: bool, _as_needed: bool) {
+    fn link_dylib_by_name(
+        &mut self,
+        name: &str,
+        _verbatim: bool,
+        _search_paths: &SearchPaths,
+        _as_needed: bool,
+    ) {
         self.cmd.arg("-l").arg(name);
     }
 
@@ -1372,7 +1396,13 @@ impl<'a> Linker for L4Bender<'a> {
 
     fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
 
-    fn link_dylib_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) {
+    fn link_dylib_by_name(
+        &mut self,
+        _name: &str,
+        _verbatim: bool,
+        _search_paths: &SearchPaths,
+        _as_needed: bool,
+    ) {
         bug!("dylibs are not supported on L4Re");
     }
 
@@ -1549,7 +1579,13 @@ impl<'a> Linker for AixLinker<'a> {
         }
     }
 
-    fn link_dylib_by_name(&mut self, name: &str, _verbatim: bool, _as_needed: bool) {
+    fn link_dylib_by_name(
+        &mut self,
+        name: &str,
+        _verbatim: bool,
+        _search_paths: &SearchPaths,
+        _as_needed: bool,
+    ) {
         self.hint_dynamic();
         self.cmd.arg(format!("-l{name}"));
     }
@@ -1755,7 +1791,13 @@ impl<'a> Linker for PtxLinker<'a> {
 
     fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
 
-    fn link_dylib_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) {
+    fn link_dylib_by_name(
+        &mut self,
+        _name: &str,
+        _verbatim: bool,
+        _search_paths: &SearchPaths,
+        _as_needed: bool,
+    ) {
         panic!("external dylibs not supported")
     }
 
@@ -1837,7 +1879,13 @@ impl<'a> Linker for LlbcLinker<'a> {
 
     fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
 
-    fn link_dylib_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) {
+    fn link_dylib_by_name(
+        &mut self,
+        _name: &str,
+        _verbatim: bool,
+        _search_paths: &SearchPaths,
+        _as_needed: bool,
+    ) {
         panic!("external dylibs not supported")
     }
 
@@ -1928,7 +1976,13 @@ impl<'a> Linker for BpfLinker<'a> {
 
     fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
 
-    fn link_dylib_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) {
+    fn link_dylib_by_name(
+        &mut self,
+        _name: &str,
+        _verbatim: bool,
+        _search_paths: &SearchPaths,
+        _as_needed: bool,
+    ) {
         panic!("external dylibs not supported")
     }