Rollup merge of #130960 - cuviper:cdylib-soname, r=petrochenkov

Only add an automatic SONAME for Rust dylibs

#126094 added an automatic relative `SONAME` to all dynamic libraries, but it was really only needed for Rust `--crate-type="dylib"`. In Fedora, it was a surprise to see `SONAME` on `"cdylib"` libraries like Python modules, especially because that generates an undesirable RPM `Provides`. We can instead add a `SONAME` just for Rust dylibs by passing the crate-type argument farther.

Ref: https://bugzilla.redhat.com/show_bug.cgi?id=2314879

Author: matthiaskrgr

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -2490,7 +2490,7 @@ fn add_order_independent_options(
         }
     }
 
-    cmd.set_output_kind(link_output_kind, out_filename);
+    cmd.set_output_kind(link_output_kind, crate_type, out_filename);
 
     add_relro_args(cmd, sess);
 

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -275,7 +275,12 @@ pub(crate) trait Linker {
     fn is_cc(&self) -> bool {
         false
     }
-    fn set_output_kind(&mut self, output_kind: LinkOutputKind, out_filename: &Path);
+    fn set_output_kind(
+        &mut self,
+        output_kind: LinkOutputKind,
+        crate_type: CrateType,
+        out_filename: &Path,
+    );
     fn link_dylib_by_name(&mut self, _name: &str, _verbatim: bool, _as_needed: bool) {
         bug!("dylib linked with unsupported linker")
     }
@@ -396,7 +401,7 @@ impl<'a> GccLinker<'a> {
         ]);
     }
 
-    fn build_dylib(&mut self, out_filename: &Path) {
+    fn build_dylib(&mut self, crate_type: CrateType, out_filename: &Path) {
         // On mac we need to tell the linker to let this library be rpathed
         if self.sess.target.is_like_osx {
             if !self.is_ld {
@@ -427,7 +432,7 @@ impl<'a> GccLinker<'a> {
                     let mut out_implib = OsString::from("--out-implib=");
                     out_implib.push(out_filename.with_file_name(implib_name));
                     self.link_arg(out_implib);
-                } else {
+                } else if crate_type == CrateType::Dylib {
                     // When dylibs are linked by a full path this value will get into `DT_NEEDED`
                     // instead of the full path, so the library can be later found in some other
                     // location than that specific path.
@@ -474,7 +479,12 @@ impl<'a> Linker for GccLinker<'a> {
         !self.is_ld
     }
 
-    fn set_output_kind(&mut self, output_kind: LinkOutputKind, out_filename: &Path) {
+    fn set_output_kind(
+        &mut self,
+        output_kind: LinkOutputKind,
+        crate_type: CrateType,
+        out_filename: &Path,
+    ) {
         match output_kind {
             LinkOutputKind::DynamicNoPicExe => {
                 if !self.is_ld && self.is_gnu {
@@ -509,10 +519,10 @@ impl<'a> Linker for GccLinker<'a> {
                     self.link_args(&["-static", "-pie", "--no-dynamic-linker", "-z", "text"]);
                 }
             }
-            LinkOutputKind::DynamicDylib => self.build_dylib(out_filename),
+            LinkOutputKind::DynamicDylib => self.build_dylib(crate_type, out_filename),
             LinkOutputKind::StaticDylib => {
                 self.link_or_cc_arg("-static");
-                self.build_dylib(out_filename);
+                self.build_dylib(crate_type, out_filename);
             }
             LinkOutputKind::WasiReactorExe => {
                 self.link_args(&["--entry", "_initialize"]);
@@ -866,7 +876,12 @@ impl<'a> Linker for MsvcLinker<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, output_kind: LinkOutputKind, out_filename: &Path) {
+    fn set_output_kind(
+        &mut self,
+        output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        out_filename: &Path,
+    ) {
         match output_kind {
             LinkOutputKind::DynamicNoPicExe
             | LinkOutputKind::DynamicPicExe
@@ -1124,7 +1139,13 @@ impl<'a> Linker for EmLinker<'a> {
         true
     }
 
-    fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
+    fn set_output_kind(
+        &mut self,
+        _output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
+    }
 
     fn link_dylib_by_name(&mut self, name: &str, _verbatim: bool, _as_needed: bool) {
         // Emscripten always links statically
@@ -1273,7 +1294,12 @@ impl<'a> Linker for WasmLd<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, output_kind: LinkOutputKind, _out_filename: &Path) {
+    fn set_output_kind(
+        &mut self,
+        output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
         match output_kind {
             LinkOutputKind::DynamicNoPicExe
             | LinkOutputKind::DynamicPicExe
@@ -1422,7 +1448,13 @@ impl<'a> Linker for L4Bender<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
+    fn set_output_kind(
+        &mut self,
+        _output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
+    }
 
     fn link_staticlib_by_name(&mut self, name: &str, _verbatim: bool, whole_archive: bool) {
         self.hint_static();
@@ -1568,7 +1600,12 @@ impl<'a> Linker for AixLinker<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, output_kind: LinkOutputKind, out_filename: &Path) {
+    fn set_output_kind(
+        &mut self,
+        output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        out_filename: &Path,
+    ) {
         match output_kind {
             LinkOutputKind::DynamicDylib => {
                 self.hint_dynamic();
@@ -1775,7 +1812,13 @@ impl<'a> Linker for PtxLinker<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
+    fn set_output_kind(
+        &mut self,
+        _output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
+    }
 
     fn link_staticlib_by_name(&mut self, _name: &str, _verbatim: bool, _whole_archive: bool) {
         panic!("staticlibs not supported")
@@ -1841,7 +1884,13 @@ impl<'a> Linker for LlbcLinker<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
+    fn set_output_kind(
+        &mut self,
+        _output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
+    }
 
     fn link_staticlib_by_name(&mut self, _name: &str, _verbatim: bool, _whole_archive: bool) {
         panic!("staticlibs not supported")
@@ -1912,7 +1961,13 @@ impl<'a> Linker for BpfLinker<'a> {
         &mut self.cmd
     }
 
-    fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
+    fn set_output_kind(
+        &mut self,
+        _output_kind: LinkOutputKind,
+        _crate_type: CrateType,
+        _out_filename: &Path,
+    ) {
+    }
 
     fn link_staticlib_by_name(&mut self, _name: &str, _verbatim: bool, _whole_archive: bool) {
         panic!("staticlibs not supported")

tests/run-make/dylib-soname/rmake.rs

@@ -7,12 +7,16 @@
 use run_make_support::{cmd, run_in_tmpdir, rustc};
 
 fn main() {
+    let check = |ty: &str| {
+        rustc().crate_name("foo").crate_type(ty).input("foo.rs").run();
+        cmd("readelf").arg("-d").arg("libfoo.so").run()
+    };
     run_in_tmpdir(|| {
-        rustc().crate_name("foo").crate_type("dylib").input("foo.rs").run();
-        cmd("readelf")
-            .arg("-d")
-            .arg("libfoo.so")
-            .run()
-            .assert_stdout_contains("Library soname: [libfoo.so]");
+        // Rust dylibs should get a relative SONAME
+        check("dylib").assert_stdout_contains("Library soname: [libfoo.so]");
+    });
+    run_in_tmpdir(|| {
+        // C dylibs should not implicitly get any SONAME
+        check("cdylib").assert_stdout_not_contains("Library soname:");
     });
 }