Override static libraries and warn on linking against that kind of libs

Author: jchlanda

compiler/rustc_metadata/src/errors.rs

@@ -704,3 +704,18 @@ pub(crate) struct MitigationLessStrictInDependency {
     pub mitigation_level: String,
     pub extern_crate: Symbol,
 }
+
+#[derive(Diagnostic)]
+pub(crate) enum StaticLinkingNotSupported<'a> {
+    #[diag(
+        "static linking of `{$lib_name}` is not supported on `{$target}`; using dynamic linking instead"
+    )]
+    #[help("remove `kind = \"static\"` and ensure a shared library is available")]
+    UserRequested { lib_name: Symbol, target: &'a str },
+
+    #[diag(
+        "library `{$lib_name}` is linked statically by a dependency, but `{$target}` requires dynamic linking; using dynamic linking instead"
+    )]
+    #[help("ensure a shared library is available")]
+    FromDependency { lib_name: Symbol, target: &'a str },
+}

compiler/rustc_metadata/src/native_libs.rs

@@ -192,6 +192,28 @@ pub(crate) fn collect(tcx: TyCtxt<'_>, LocalCrate: LocalCrate) -> Vec<NativeLib>
         }
     }
     collector.process_command_line();
+    for lib in &mut collector.libs {
+        if tcx.sess.target.env == Env::Pauthtest {
+            if let NativeLibKind::Static { .. } = lib.kind {
+                if !tcx.sess.opts.unstable_opts.ui_testing {
+                    let diag = if lib.foreign_module.is_none() {
+                        errors::StaticLinkingNotSupported::UserRequested {
+                            lib_name: lib.name,
+                            target: tcx.sess.target.llvm_target.as_ref(),
+                        }
+                    } else {
+                        errors::StaticLinkingNotSupported::FromDependency {
+                            lib_name: lib.name,
+                            target: tcx.sess.target.llvm_target.as_ref(),
+                        }
+                    };
+                    tcx.dcx().emit_warn(diag);
+                }
+
+                lib.kind = NativeLibKind::Dylib { as_needed: None };
+            }
+        }
+    }
     collector.libs
 }
 

src/doc/rustc/src/platform-support/aarch64-unknown-linux-pauthtest.md

@@ -391,8 +391,9 @@ The following categories are supported (all present in tree):
 * End-to-end execution tests
   * Rust-driven quicksort (pauth-quicksort-rust-driver)
   * C-driven quicksort (pauth-quicksort-c-driver)
-* UI error reporting (the target does not support `+crt-static`)
+* UI error/warning reporting (the target does not support static linking)
   * crt-static-pauthtest.rs
+  * pauth-static-link-warning
 
 All tests from `assembly-llvm`, `codegen-llvm`, `codegen-units`, `coverage`,
 `crashes`, `incremental`, `library`, `mir-opt`, `run-make`, `ui` and
@@ -413,6 +414,7 @@ x.py test --target aarch64-unknown-linux-pauthtest --force-rerun assembly-llvm \
   tests/codegen-llvm/pauth/pauth-init-fini.rs \
   tests/run-make/pauth-quicksort-rust-driver \
   tests/run-make/pauth-quicksort-c-driver \
+  tests/run-make/pauth-static-link-warning \
   tests/ui/statics/crt-static-pauthtest.rs
 ```
 

tests/incremental/auxiliary/issue-54059.rs

@@ -40,8 +40,7 @@ proc_macro_expr_impl! {
     }
 }
 
-#[cfg_attr(target_env = "pauthtest", link(name = "rust_test_helpers", kind = "dylib"))]
-#[cfg_attr(not(target_env = "pauthtest"), link(name = "rust_test_helpers"))]
+#[link(name = "rust_test_helpers", kind = "static")]
 extern "C" {
     pub fn rust_dbg_extern_identity_u64(v: u64) -> u64;
 }

tests/run-make/pauth-static-link-warning/helper.c

@@ -0,0 +1 @@
+int helper_function() { return 42; }

tests/run-make/pauth-static-link-warning/main.rs

@@ -0,0 +1,10 @@
+#[link(name = "helper", kind = "static")]
+extern "C" {
+    fn helper_function() -> i32;
+}
+
+fn main() {
+    unsafe {
+        assert!(42 == helper_function());
+    }
+}

tests/run-make/pauth-static-link-warning/main_cmd_line.rs

@@ -0,0 +1,9 @@
+extern "C" {
+    fn helper_function() -> i32;
+}
+
+fn main() {
+    unsafe {
+        assert!(42 == helper_function());
+    }
+}

tests/run-make/pauth-static-link-warning/rmake.rs

@@ -0,0 +1,46 @@
+// Make sure that for `aarch64-unknown-linux-pauthtest` compiler emits warning when static
+// libraries are linked. Test both foreign module linked from #[link] directive and command line
+// invocations.
+
+//@ only-aarch64-unknown-linux-pauthtest
+// ignore-tidy-linelength
+
+use run_make_support::{cc, env_var, regex, run, rustc};
+
+fn main() {
+    let input = "helper";
+    let input_name = format!("{input}.c");
+    let lib_name = format!("{}{input}.{}", "lib", "a");
+    // Build a static library
+    cc().out_exe(&lib_name)
+        .input(&input_name)
+        .args(&["-target", "aarch64-unknown-linux-pauthtest", "-march=armv8.3-a+pauth", "-c"])
+        .run();
+
+    // Check against foreign module warning: #[link(name = "helper", kind = "static")]
+    let stderr_foreign_module = rustc()
+        .target("aarch64-unknown-linux-pauthtest")
+        .input("main.rs")
+        .linker(&env_var("CC"))
+        .link_args(&env_var("CC_DEFAULT_FLAGS"))
+        .arg("-L.")
+        .run()
+        .stderr_utf8();
+    run("main");
+    let re_foreign_moule = regex::Regex::new( r"(?s)warning: library `helper`.*linked statically.*aarch64-unknown-linux-pauthtest.*requires dynamic linking.*using dynamic linking instead").unwrap();
+    assert!(re_foreign_moule.is_match(&stderr_foreign_module));
+
+    // Check against command line warning: -lstatic=helper
+    let stderr_command_line = rustc()
+        .target("aarch64-unknown-linux-pauthtest")
+        .input("main_cmd_line.rs")
+        .linker(&env_var("CC"))
+        .link_args(&env_var("CC_DEFAULT_FLAGS"))
+        .arg("-L.")
+        .arg("-lstatic=helper")
+        .run()
+        .stderr_utf8();
+    run("main_cmd_line");
+    let re_cmd_line = regex::Regex::new( r"(?s)warning: static linking of `helper`.*is not supported on.*aarch64-unknown-linux-pauthtest.*using dynamic linking instead").unwrap();
+    assert!(re_cmd_line.is_match(&stderr_command_line));
+}

tests/ui/abi/abi-sysv64-arg-passing.rs

@@ -106,8 +106,7 @@ mod tests {
         Some(u64),
     }
 
-    #[cfg_attr(target_env = "pauthtest", link(name = "rust_test_helpers", kind = "dylib"))]
-    #[cfg_attr(not(target_env = "pauthtest"), link(name = "rust_test_helpers", kind = "static"))]
+    #[link(name = "rust_test_helpers", kind = "static")]
     extern "sysv64" {
         pub fn rust_int8_to_int32(_: i8) -> i32;
         pub fn rust_dbg_extern_identity_u8(v: u8) -> u8;

tests/ui/abi/anon-extern-mod.rs

@@ -1,7 +1,6 @@
 //@ run-pass
 
-#[cfg_attr(target_env = "pauthtest", link(name = "rust_test_helpers", kind = "dylib"))]
-#[cfg_attr(not(target_env = "pauthtest"), link(name = "rust_test_helpers", kind = "static"))]
+#[link(name = "rust_test_helpers", kind = "static")]
 extern "C" {
     fn rust_get_test_int() -> isize;
 }