Auto merge of #146892 - GuillaumeGomez:rollup-fa7lp0n, r=GuillaumeGomez

Rollup of 5 pull requests

Successful merges:

 - rust-lang/rust#146795 (Enable `limit_rdylib_exports` on wasm targets)
 - rust-lang/rust#146828 (fix a crash in rustdoc merge finalize without input file)
 - rust-lang/rust#146848 (Add x86_64-unknown-motor (Motor OS) tier 3 target)
 - rust-lang/rust#146884 (Fix modification check of `rustdoc-json-types`)
 - rust-lang/rust#146887 (Remove unused #![feature(get_mut_unchecked)] in Rc and Arc examples)

r? `@ghost`
`@rustbot` modify labels: rollup

6 files changed, 79 insertions, 5 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/linker.rs b/compiler/rustc_codegen_ssa/src/back/linker.rs
index a2efd420a32..b90be2faa08 100644
--- a/compiler/rustc_codegen_ssa/src/back/linker.rs
+++ b/compiler/rustc_codegen_ssa/src/back/linker.rs
@@ -845,6 +845,11 @@ impl<'a> Linker for GccLinker<'a> {
                 self.sess.dcx().emit_fatal(errors::VersionScriptWriteFailure { error });
             }
             self.link_arg("--dynamic-list").link_arg(path);
+        } else if self.sess.target.is_like_wasm {
+            self.link_arg("--no-export-dynamic");
+            for (sym, _) in symbols {
+                self.link_arg("--export").link_arg(sym);
+            }
         } else {
             // Write an LD version script
             let res: io::Result<()> = try {
diff --git a/compiler/rustc_target/src/spec/base/mod.rs b/compiler/rustc_target/src/spec/base/mod.rs
index be15da7329d..6ab8597a4ec 100644
--- a/compiler/rustc_target/src/spec/base/mod.rs
+++ b/compiler/rustc_target/src/spec/base/mod.rs
@@ -21,6 +21,7 @@ pub(crate) mod linux_uclibc;
 pub(crate) mod linux_wasm;
 pub(crate) mod lynxos178;
 pub(crate) mod managarm_mlibc;
+pub(crate) mod motor;
 pub(crate) mod msvc;
 pub(crate) mod netbsd;
 pub(crate) mod nto_qnx;
diff --git a/compiler/rustc_target/src/spec/base/motor.rs b/compiler/rustc_target/src/spec/base/motor.rs
new file mode 100644
index 00000000000..18485b2cef2
--- /dev/null
+++ b/compiler/rustc_target/src/spec/base/motor.rs
@@ -0,0 +1,34 @@
+use crate::spec::{
+    Cc, FramePointer, LinkerFlavor, Lld, PanicStrategy, StackProbeType, TargetOptions,
+};
+
+pub(crate) fn opts() -> TargetOptions {
+    let pre_link_args = TargetOptions::link_args(
+        LinkerFlavor::Gnu(Cc::No, Lld::No),
+        &[
+            "-e",
+            "motor_start",
+            "--no-undefined",
+            "--error-unresolved-symbols",
+            "--no-undefined-version",
+            "-u",
+            "__rust_abort",
+        ],
+    );
+    TargetOptions {
+        os: "motor".into(),
+        executables: true,
+        // TLS is false below because if true, the compiler assumes
+        // we handle TLS at the ELF loading level, which we don't.
+        // We use "OS level" TLS (see thread/local.rs in stdlib).
+        has_thread_local: false,
+        frame_pointer: FramePointer::NonLeaf,
+        linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::No),
+        main_needs_argc_argv: true,
+        panic_strategy: PanicStrategy::Abort,
+        pre_link_args,
+        stack_probes: StackProbeType::Inline,
+        supports_stack_protector: true,
+        ..Default::default()
+    }
+}
diff --git a/compiler/rustc_target/src/spec/base/wasm.rs b/compiler/rustc_target/src/spec/base/wasm.rs
index 88e7af5e669..7ede45766ea 100644
--- a/compiler/rustc_target/src/spec/base/wasm.rs
+++ b/compiler/rustc_target/src/spec/base/wasm.rs
@@ -81,11 +81,6 @@ pub(crate) fn options() -> TargetOptions {
         // threaded model which will legalize atomics to normal operations.
         singlethread: true,
 
-        // Symbol visibility takes care of this for the WebAssembly.
-        // Additionally the only known linker, LLD, doesn't support the script
-        // arguments just yet
-        limit_rdylib_exports: false,
-
         // we use the LLD shipped with the Rust toolchain by default
         linker: Some("rust-lld".into()),
         linker_flavor: LinkerFlavor::WasmLld(Cc::No),
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index f705af52bd8..c40358af593 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -1642,6 +1642,7 @@ supported_targets! {
     ("aarch64-unknown-hermit", aarch64_unknown_hermit),
     ("riscv64gc-unknown-hermit", riscv64gc_unknown_hermit),
     ("x86_64-unknown-hermit", x86_64_unknown_hermit),
+    ("x86_64-unknown-motor", x86_64_unknown_motor),
 
     ("x86_64-unikraft-linux-musl", x86_64_unikraft_linux_musl),
 
diff --git a/compiler/rustc_target/src/spec/targets/x86_64_unknown_motor.rs b/compiler/rustc_target/src/spec/targets/x86_64_unknown_motor.rs
new file mode 100644
index 00000000000..0fd43357a76
--- /dev/null
+++ b/compiler/rustc_target/src/spec/targets/x86_64_unknown_motor.rs
@@ -0,0 +1,38 @@
+use crate::spec::{
+    CodeModel, LinkSelfContainedDefault, LldFlavor, RelocModel, RelroLevel, Target, base,
+};
+
+pub(crate) fn target() -> Target {
+    let mut base = base::motor::opts();
+    base.cpu = "x86-64".into();
+    base.max_atomic_width = Some(64);
+    base.code_model = Some(CodeModel::Small);
+
+    // We want fully static relocatable binaries. It was surprisingly
+    // difficult to make it happen reliably, especially various
+    // linker-related options below. Mostly trial and error.
+    base.position_independent_executables = true;
+    base.relro_level = RelroLevel::Full;
+    base.static_position_independent_executables = true;
+    base.relocation_model = RelocModel::Pic;
+    base.lld_flavor_json = LldFlavor::Ld;
+    base.link_self_contained = LinkSelfContainedDefault::True;
+    base.dynamic_linking = false;
+    base.crt_static_default = true;
+    base.crt_static_respected = true;
+
+    Target {
+        llvm_target: "x86_64-unknown-none-elf".into(),
+        metadata: crate::spec::TargetMetadata {
+            description: Some("Motor OS".into()),
+            tier: Some(3),
+            host_tools: None,
+            std: None,
+        },
+        pointer_width: 64,
+        data_layout:
+            "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128".into(),
+        arch: "x86_64".into(),
+        options: base,
+    }
+}