Auto merge of #93202 - matthiaskrgr:rollup-rki39xg, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - #85967 (add support for the l4-bender linker on the x86_64-unknown-l4re-uclibc tier 3 target)
 - #92828 (Print a helpful message if unwinding aborts when it reaches a nounwind function)
 - #93012 (Update pulldown-cmark version to fix markdown list issue)
 - #93116 (Simplify use of `map_or`)
 - #93132 (Increase the format version of rustdoc-json-types)
 - #93147 (Interner cleanups)
 - #93153 (Reject unsupported naked functions)
 - #93170 (Add missing GUI test explanations)
 - #93172 (rustdoc: remove dashed underline under main heading)

Failed merges:

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

Cargo.lock

@@ -689,7 +689,7 @@ dependencies = [
  "clippy_utils",
  "if_chain",
  "itertools 0.10.1",
- "pulldown-cmark 0.9.0",
+ "pulldown-cmark",
  "quine-mc_cluskey",
  "regex-syntax",
  "rustc-semver",
@@ -2186,9 +2186,9 @@ dependencies = [
 
 [[package]]
 name = "mdbook"
-version = "0.4.14"
+version = "0.4.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f6e77253c46a90eb7e96b2807201dab941a4db5ea05eca5aaaf7027395f352b3"
+checksum = "241f10687eb3b4e0634b3b4e423f97c5f1efbd69dc9522e24a8b94583eeec3c6"
 dependencies = [
  "ammonia",
  "anyhow",
@@ -2201,7 +2201,7 @@ dependencies = [
  "log",
  "memchr",
  "opener",
- "pulldown-cmark 0.8.0",
+ "pulldown-cmark",
  "regex",
  "serde",
  "serde_derive",
@@ -2865,27 +2865,16 @@ dependencies = [
 
 [[package]]
 name = "pulldown-cmark"
-version = "0.8.0"
+version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ffade02495f22453cd593159ea2f59827aae7f53fa8323f756799b670881dcf8"
+checksum = "34f197a544b0c9ab3ae46c359a7ec9cbbb5c7bf97054266fecb7ead794a181d6"
 dependencies = [
  "bitflags",
  "getopts",
  "memchr",
  "unicase",
 ]
 
-[[package]]
-name = "pulldown-cmark"
-version = "0.9.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "acd16514d1af5f7a71f909a44ef253cdb712a376d7ebc8ae4a471a9be9743548"
-dependencies = [
- "bitflags",
- "memchr",
- "unicase",
-]
-
 [[package]]
 name = "punycode"
 version = "0.4.1"
@@ -4440,7 +4429,7 @@ dependencies = [
  "expect-test",
  "itertools 0.9.0",
  "minifier",
- "pulldown-cmark 0.9.0",
+ "pulldown-cmark",
  "rayon",
  "regex",
  "rustdoc-json-types",

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1159,6 +1159,7 @@ pub fn linker_and_flavor(sess: &Session) -> (PathBuf, LinkerFlavor) {
                     LinkerFlavor::Lld(_) => "lld",
                     LinkerFlavor::PtxLinker => "rust-ptx-linker",
                     LinkerFlavor::BpfLinker => "bpf-linker",
+                    LinkerFlavor::L4Bender => "l4-bender",
                 }),
                 flavor,
             )),

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -126,7 +126,6 @@ pub fn get_linker<'a>(
     // FIXME: Move `/LIBPATH` addition for uwp targets from the linker construction
     // to the linker args construction.
     assert!(cmd.get_args().is_empty() || sess.target.vendor == "uwp");
-
     match flavor {
         LinkerFlavor::Lld(LldFlavor::Link) | LinkerFlavor::Msvc => {
             Box::new(MsvcLinker { cmd, sess }) as Box<dyn Linker>
@@ -149,6 +148,8 @@ pub fn get_linker<'a>(
         LinkerFlavor::PtxLinker => Box::new(PtxLinker { cmd, sess }) as Box<dyn Linker>,
 
         LinkerFlavor::BpfLinker => Box::new(BpfLinker { cmd, sess }) as Box<dyn Linker>,
+
+        LinkerFlavor::L4Bender => Box::new(L4Bender::new(cmd, sess)) as Box<dyn Linker>,
     }
 }
 
@@ -1355,6 +1356,157 @@ impl<'a> Linker for WasmLd<'a> {
     }
 }
 
+/// Linker shepherd script for L4Re (Fiasco)
+pub struct L4Bender<'a> {
+    cmd: Command,
+    sess: &'a Session,
+    hinted_static: bool,
+}
+
+impl<'a> Linker for L4Bender<'a> {
+    fn link_dylib(&mut self, _lib: Symbol, _verbatim: bool, _as_needed: bool) {
+        bug!("dylibs are not supported on L4Re");
+    }
+    fn link_staticlib(&mut self, lib: Symbol, _verbatim: bool) {
+        self.hint_static();
+        self.cmd.arg(format!("-PC{}", lib));
+    }
+    fn link_rlib(&mut self, lib: &Path) {
+        self.hint_static();
+        self.cmd.arg(lib);
+    }
+    fn include_path(&mut self, path: &Path) {
+        self.cmd.arg("-L").arg(path);
+    }
+    fn framework_path(&mut self, _: &Path) {
+        bug!("frameworks are not supported on L4Re");
+    }
+    fn output_filename(&mut self, path: &Path) {
+        self.cmd.arg("-o").arg(path);
+    }
+
+    fn add_object(&mut self, path: &Path) {
+        self.cmd.arg(path);
+    }
+
+    fn full_relro(&mut self) {
+        self.cmd.arg("-zrelro");
+        self.cmd.arg("-znow");
+    }
+
+    fn partial_relro(&mut self) {
+        self.cmd.arg("-zrelro");
+    }
+
+    fn no_relro(&mut self) {
+        self.cmd.arg("-znorelro");
+    }
+
+    fn cmd(&mut self) -> &mut Command {
+        &mut self.cmd
+    }
+
+    fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
+
+    fn link_rust_dylib(&mut self, _: Symbol, _: &Path) {
+        panic!("Rust dylibs not supported");
+    }
+
+    fn link_framework(&mut self, _framework: Symbol, _as_needed: bool) {
+        bug!("frameworks not supported on L4Re");
+    }
+
+    fn link_whole_staticlib(&mut self, lib: Symbol, _verbatim: bool, _search_path: &[PathBuf]) {
+        self.hint_static();
+        self.cmd.arg("--whole-archive").arg(format!("-l{}", lib));
+        self.cmd.arg("--no-whole-archive");
+    }
+
+    fn link_whole_rlib(&mut self, lib: &Path) {
+        self.hint_static();
+        self.cmd.arg("--whole-archive").arg(lib).arg("--no-whole-archive");
+    }
+
+    fn gc_sections(&mut self, keep_metadata: bool) {
+        if !keep_metadata {
+            self.cmd.arg("--gc-sections");
+        }
+    }
+
+    fn no_gc_sections(&mut self) {
+        self.cmd.arg("--no-gc-sections");
+    }
+
+    fn optimize(&mut self) {
+        // GNU-style linkers support optimization with -O. GNU ld doesn't
+        // need a numeric argument, but other linkers do.
+        if self.sess.opts.optimize == config::OptLevel::Default
+            || self.sess.opts.optimize == config::OptLevel::Aggressive
+        {
+            self.cmd.arg("-O1");
+        }
+    }
+
+    fn pgo_gen(&mut self) {}
+
+    fn debuginfo(&mut self, strip: Strip) {
+        match strip {
+            Strip::None => {}
+            Strip::Debuginfo => {
+                self.cmd().arg("--strip-debug");
+            }
+            Strip::Symbols => {
+                self.cmd().arg("--strip-all");
+            }
+        }
+    }
+
+    fn no_default_libraries(&mut self) {
+        self.cmd.arg("-nostdlib");
+    }
+
+    fn export_symbols(&mut self, _: &Path, _: CrateType, _: &[String]) {
+        // ToDo, not implemented, copy from GCC
+        self.sess.warn("exporting symbols not implemented yet for L4Bender");
+        return;
+    }
+
+    fn subsystem(&mut self, subsystem: &str) {
+        self.cmd.arg(&format!("--subsystem {}", subsystem));
+    }
+
+    fn reset_per_library_state(&mut self) {
+        self.hint_static(); // Reset to default before returning the composed command line.
+    }
+
+    fn group_start(&mut self) {
+        self.cmd.arg("--start-group");
+    }
+
+    fn group_end(&mut self) {
+        self.cmd.arg("--end-group");
+    }
+
+    fn linker_plugin_lto(&mut self) {}
+
+    fn control_flow_guard(&mut self) {}
+
+    fn no_crt_objects(&mut self) {}
+}
+
+impl<'a> L4Bender<'a> {
+    pub fn new(cmd: Command, sess: &'a Session) -> L4Bender<'a> {
+        L4Bender { cmd: cmd, sess: sess, hinted_static: false }
+    }
+
+    fn hint_static(&mut self) {
+        if !self.hinted_static {
+            self.cmd.arg("-static");
+            self.hinted_static = true;
+        }
+    }
+}
+
 pub(crate) fn exported_symbols(tcx: TyCtxt<'_>, crate_type: CrateType) -> Vec<String> {
     if let Some(ref exports) = tcx.sess.target.override_export_symbols {
         return exports.clone();

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -477,6 +477,28 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         helper.do_call(self, &mut bx, fn_abi, llfn, &args, None, cleanup);
     }
 
+    fn codegen_abort_terminator(
+        &mut self,
+        helper: TerminatorCodegenHelper<'tcx>,
+        mut bx: Bx,
+        terminator: &mir::Terminator<'tcx>,
+    ) {
+        let span = terminator.source_info.span;
+        self.set_debug_loc(&mut bx, terminator.source_info);
+
+        // Get the location information.
+        let location = self.get_caller_location(&mut bx, terminator.source_info).immediate();
+
+        // Obtain the panic entry point.
+        let def_id = common::langcall(bx.tcx(), Some(span), "", LangItem::PanicNoUnwind);
+        let instance = ty::Instance::mono(bx.tcx(), def_id);
+        let fn_abi = bx.fn_abi_of_instance(instance, ty::List::empty());
+        let llfn = bx.get_fn_addr(instance);
+
+        // Codegen the actual panic invoke/call.
+        helper.do_call(self, &mut bx, fn_abi, llfn, &[location], None, None);
+    }
+
     /// Returns `true` if this is indeed a panic intrinsic and codegen is done.
     fn codegen_panic_intrinsic(
         &mut self,
@@ -1014,10 +1036,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             mir::TerminatorKind::Resume => self.codegen_resume_terminator(helper, bx),
 
             mir::TerminatorKind::Abort => {
-                bx.abort();
-                // `abort` does not terminate the block, so we still need to generate
-                // an `unreachable` terminator after it.
-                bx.unreachable();
+                self.codegen_abort_terminator(helper, bx, terminator);
             }
 
             mir::TerminatorKind::Goto { target } => {

compiler/rustc_error_codes/src/error_codes.rs

@@ -486,6 +486,7 @@ E0783: include_str!("./error_codes/E0783.md"),
 E0784: include_str!("./error_codes/E0784.md"),
 E0785: include_str!("./error_codes/E0785.md"),
 E0786: include_str!("./error_codes/E0786.md"),
+E0787: include_str!("./error_codes/E0787.md"),
 ;
 //  E0006, // merged with E0005
 //  E0008, // cannot bind by-move into a pattern guard

compiler/rustc_error_codes/src/error_codes/E0787.md

@@ -0,0 +1,28 @@
+An unsupported naked function definition.
+
+Erroneous code example:
+
+```compile_fail,E0787
+#![feature(naked_functions)]
+
+#[naked]
+pub extern "C" fn f() -> u32 {
+    42
+}
+```
+
+The naked functions must be defined using a single inline assembly
+block.
+
+The execution must never fall through past the end of the assembly
+code so the block must use `noreturn` option. The asm block can also
+use `att_syntax` and `raw` options, but others options are not allowed.
+
+The asm block must not contain any operands other than `const` and
+`sym`.
+
+### Additional information
+
+For more information, please see [RFC 2972].
+
+[RFC 2972]: https://github.com/rust-lang/rfcs/blob/master/text/2972-constrained-naked.md

compiler/rustc_hir/src/lang_items.rs

@@ -283,6 +283,7 @@ language_item_table! {
     PanicInfo,               sym::panic_info,          panic_info,                 Target::Struct,         GenericRequirement::None;
     PanicLocation,           sym::panic_location,      panic_location,             Target::Struct,         GenericRequirement::None;
     PanicImpl,               sym::panic_impl,          panic_impl,                 Target::Fn,             GenericRequirement::None;
+    PanicNoUnwind,           sym::panic_no_unwind,     panic_no_unwind,            Target::Fn,             GenericRequirement::Exact(0);
     /// libstd panic entry point. Necessary for const eval to be able to catch it
     BeginPanic,              sym::begin_panic,         begin_panic_fn,             Target::Fn,             GenericRequirement::None;
 

compiler/rustc_lint/src/lib.rs

@@ -481,6 +481,11 @@ fn register_builtins(store: &mut LintStore, no_interleave_lints: bool) {
          <https://github.com/rust-lang/rust/issues/59014> for more information",
     );
     store.register_removed("plugin_as_library", "plugins have been deprecated and retired");
+    store.register_removed(
+        "unsupported_naked_functions",
+        "converted into hard error, see RFC 2972 \
+         <https://github.com/rust-lang/rfcs/blob/master/text/2972-constrained-naked.md> for more information",
+    );
 }
 
 fn register_internals(store: &mut LintStore) {