Sync from rust 2025/08/03

build_system/src/test.rs

@@ -561,8 +561,6 @@ fn asm_tests(env: &Env, args: &TestArg) -> Result<(), String> {
     // FIXME: create a function "display_if_not_quiet" or something along the line.
     println!("[TEST] rustc asm test suite");
 
-    env.insert("COMPILETEST_FORCE_STAGE0".to_string(), "1".to_string());
-
     let codegen_backend_path = format!(
         "{pwd}/target/{channel}/librustc_codegen_gcc.{dylib_ext}",
         pwd = std::env::current_dir()
@@ -588,7 +586,9 @@ fn asm_tests(env: &Env, args: &TestArg) -> Result<(), String> {
             &"always",
             &"--stage",
             &"0",
-            &"tests/assembly/asm",
+            &"--set",
+            &"build.compiletest-allow-stage0=true",
+            &"tests/assembly-llvm/asm",
             &"--compiletest-rustc-args",
             &rustc_args,
         ],
@@ -1047,7 +1047,6 @@ where
 
     // FIXME: create a function "display_if_not_quiet" or something along the line.
     println!("[TEST] rustc {test_type} test suite");
-    env.insert("COMPILETEST_FORCE_STAGE0".to_string(), "1".to_string());
 
     let extra =
         if args.is_using_gcc_master_branch() { "" } else { " -Csymbol-mangling-version=v0" };
@@ -1070,6 +1069,8 @@ where
             &"always",
             &"--stage",
             &"0",
+            &"--set",
+            &"build.compiletest-allow-stage0=true",
             &format!("tests/{test_type}"),
             &"--compiletest-rustc-args",
             &rustc_args,

messages.ftl

@@ -3,12 +3,6 @@ codegen_gcc_unwinding_inline_asm =
 
 codegen_gcc_copy_bitcode = failed to copy bitcode to object file: {$err}
 
-codegen_gcc_dynamic_linking_with_lto =
-    cannot prefer dynamic linking when performing LTO
-    .note = only 'staticlib', 'bin', and 'cdylib' outputs are supported with LTO
-
-codegen_gcc_lto_disallowed = lto can only be run for executables, cdylibs and static library outputs
-
-codegen_gcc_lto_dylib = lto cannot be used for `dylib` crate type without `-Zdylib-lto`
-
 codegen_gcc_lto_bitcode_from_rlib = failed to get bitcode from object file for LTO ({$gcc_err})
+
+codegen_gcc_explicit_tail_calls_unsupported = explicit tail calls with the 'become' keyword are not implemented in the GCC backend

patches/0001-Add-stdarch-Cargo.toml-for-testing.patch

@@ -1,29 +1,28 @@
-From b8f3eed3053c9333b5dfbeaeb2a6a65a4b3156df Mon Sep 17 00:00:00 2001
-From: Antoni Boucher <bouanto@zoho.com>
-Date: Tue, 29 Aug 2023 13:06:34 -0400
+From 190e26c9274b3c93a9ee3516b395590e6bd9213b Mon Sep 17 00:00:00 2001
+From: None <none@example.com>
+Date: Sun, 3 Aug 2025 19:54:56 -0400
 Subject: [PATCH] Patch 0001-Add-stdarch-Cargo.toml-for-testing.patch
 
 ---
- library/stdarch/Cargo.toml | 23 +++++++++++++++++++++++
- 1 file changed, 23 insertions(+)
+ library/stdarch/Cargo.toml | 20 ++++++++++++++++++++
+ 1 file changed, 20 insertions(+)
  create mode 100644 library/stdarch/Cargo.toml
 
 diff --git a/library/stdarch/Cargo.toml b/library/stdarch/Cargo.toml
 new file mode 100644
-index 0000000..4c63700
+index 0000000..bd6725c
 --- /dev/null
 +++ b/library/stdarch/Cargo.toml
-@@ -0,0 +1,21 @@
+@@ -0,0 +1,20 @@
 +[workspace]
 +resolver = "1"
 +members = [
-+  "crates/core_arch",
-+  "crates/std_detect",
-+  "crates/stdarch-gen-arm",
++  "crates/*",
 +  #"examples/"
 +]
 +exclude = [
-+  "crates/wasm-assert-instr-tests"
++  "crates/wasm-assert-instr-tests",
++  "rust_programs",
 +]
 +
 +[profile.release]
@@ -36,5 +35,5 @@ index 0000000..4c63700
 +opt-level = 3
 +incremental = true
 -- 
-2.42.0
+2.50.1
 

rust-toolchain

@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2025-07-21"
+channel = "nightly-2025-08-03"
 components = ["rust-src", "rustc-dev", "llvm-tools-preview"]

src/attributes.rs

@@ -2,8 +2,8 @@
 use gccjit::FnAttribute;
 use gccjit::Function;
 #[cfg(feature = "master")]
-use rustc_attr_data_structures::InlineAttr;
-use rustc_attr_data_structures::InstructionSetAttr;
+use rustc_hir::attrs::InlineAttr;
+use rustc_hir::attrs::InstructionSetAttr;
 #[cfg(feature = "master")]
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 #[cfg(feature = "master")]

src/back/lto.rs

@@ -25,35 +25,21 @@ use std::sync::Arc;
 use gccjit::{Context, OutputKind};
 use object::read::archive::ArchiveFile;
 use rustc_codegen_ssa::back::lto::{SerializedModule, ThinModule, ThinShared};
-use rustc_codegen_ssa::back::symbol_export;
 use rustc_codegen_ssa::back::write::{CodegenContext, FatLtoInput};
 use rustc_codegen_ssa::traits::*;
 use rustc_codegen_ssa::{ModuleCodegen, ModuleKind, looks_like_rust_object_file};
 use rustc_data_structures::memmap::Mmap;
 use rustc_errors::{DiagCtxtHandle, FatalError};
-use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_middle::bug;
 use rustc_middle::dep_graph::WorkProduct;
-use rustc_middle::middle::exported_symbols::{SymbolExportInfo, SymbolExportLevel};
-use rustc_session::config::{CrateType, Lto};
+use rustc_session::config::Lto;
 use rustc_target::spec::RelocModel;
 use tempfile::{TempDir, tempdir};
 
 use crate::back::write::save_temp_bitcode;
-use crate::errors::{DynamicLinkingWithLTO, LtoBitcodeFromRlib, LtoDisallowed, LtoDylib};
+use crate::errors::LtoBitcodeFromRlib;
 use crate::{GccCodegenBackend, GccContext, SyncContext, to_gcc_opt_level};
 
-pub fn crate_type_allows_lto(crate_type: CrateType) -> bool {
-    match crate_type {
-        CrateType::Executable
-        | CrateType::Dylib
-        | CrateType::Staticlib
-        | CrateType::Cdylib
-        | CrateType::Sdylib => true,
-        CrateType::Rlib | CrateType::ProcMacro => false,
-    }
-}
-
 struct LtoData {
     // TODO(antoyo): use symbols_below_threshold.
     //symbols_below_threshold: Vec<String>,
@@ -63,18 +49,9 @@ struct LtoData {
 
 fn prepare_lto(
     cgcx: &CodegenContext<GccCodegenBackend>,
+    each_linked_rlib_for_lto: &[PathBuf],
     dcx: DiagCtxtHandle<'_>,
 ) -> Result<LtoData, FatalError> {
-    let export_threshold = match cgcx.lto {
-        // We're just doing LTO for our one crate
-        Lto::ThinLocal => SymbolExportLevel::Rust,
-
-        // We're doing LTO for the entire crate graph
-        Lto::Fat | Lto::Thin => symbol_export::crates_export_threshold(&cgcx.crate_types),
-
-        Lto::No => panic!("didn't request LTO but we're doing LTO"),
-    };
-
     let tmp_path = match tempdir() {
         Ok(tmp_path) => tmp_path,
         Err(error) => {
@@ -83,20 +60,6 @@ fn prepare_lto(
         }
     };
 
-    let symbol_filter = &|&(ref name, info): &(String, SymbolExportInfo)| {
-        if info.level.is_below_threshold(export_threshold) || info.used {
-            Some(name.clone())
-        } else {
-            None
-        }
-    };
-    let exported_symbols = cgcx.exported_symbols.as_ref().expect("needs exported symbols for LTO");
-    let mut symbols_below_threshold = {
-        let _timer = cgcx.prof.generic_activity("GCC_lto_generate_symbols_below_threshold");
-        exported_symbols[&LOCAL_CRATE].iter().filter_map(symbol_filter).collect::<Vec<String>>()
-    };
-    info!("{} symbols to preserve in this crate", symbols_below_threshold.len());
-
     // If we're performing LTO for the entire crate graph, then for each of our
     // upstream dependencies, find the corresponding rlib and load the bitcode
     // from the archive.
@@ -105,32 +68,7 @@ fn prepare_lto(
     // with either fat or thin LTO
     let mut upstream_modules = Vec::new();
     if cgcx.lto != Lto::ThinLocal {
-        // Make sure we actually can run LTO
-        for crate_type in cgcx.crate_types.iter() {
-            if !crate_type_allows_lto(*crate_type) {
-                dcx.emit_err(LtoDisallowed);
-                return Err(FatalError);
-            }
-            if *crate_type == CrateType::Dylib && !cgcx.opts.unstable_opts.dylib_lto {
-                dcx.emit_err(LtoDylib);
-                return Err(FatalError);
-            }
-        }
-
-        if cgcx.opts.cg.prefer_dynamic && !cgcx.opts.unstable_opts.dylib_lto {
-            dcx.emit_err(DynamicLinkingWithLTO);
-            return Err(FatalError);
-        }
-
-        for &(cnum, ref path) in cgcx.each_linked_rlib_for_lto.iter() {
-            let exported_symbols =
-                cgcx.exported_symbols.as_ref().expect("needs exported symbols for LTO");
-            {
-                let _timer = cgcx.prof.generic_activity("GCC_lto_generate_symbols_below_threshold");
-                symbols_below_threshold
-                    .extend(exported_symbols[&cnum].iter().filter_map(symbol_filter));
-            }
-
+        for path in each_linked_rlib_for_lto {
             let archive_data = unsafe {
                 Mmap::map(File::open(path).expect("couldn't open rlib")).expect("couldn't map rlib")
             };
@@ -174,19 +112,18 @@ fn save_as_file(obj: &[u8], path: &Path) -> Result<(), LtoBitcodeFromRlib> {
 /// for further optimization.
 pub(crate) fn run_fat(
     cgcx: &CodegenContext<GccCodegenBackend>,
+    each_linked_rlib_for_lto: &[PathBuf],
     modules: Vec<FatLtoInput<GccCodegenBackend>>,
-    cached_modules: Vec<(SerializedModule<ModuleBuffer>, WorkProduct)>,
 ) -> Result<ModuleCodegen<GccContext>, FatalError> {
     let dcx = cgcx.create_dcx();
     let dcx = dcx.handle();
-    let lto_data = prepare_lto(cgcx, dcx)?;
+    let lto_data = prepare_lto(cgcx, each_linked_rlib_for_lto, dcx)?;
     /*let symbols_below_threshold =
     lto_data.symbols_below_threshold.iter().map(|c| c.as_ptr()).collect::<Vec<_>>();*/
     fat_lto(
         cgcx,
         dcx,
         modules,
-        cached_modules,
         lto_data.upstream_modules,
         lto_data.tmp_path,
         //&lto_data.symbols_below_threshold,
@@ -197,7 +134,6 @@ fn fat_lto(
     cgcx: &CodegenContext<GccCodegenBackend>,
     _dcx: DiagCtxtHandle<'_>,
     modules: Vec<FatLtoInput<GccCodegenBackend>>,
-    cached_modules: Vec<(SerializedModule<ModuleBuffer>, WorkProduct)>,
     mut serialized_modules: Vec<(SerializedModule<ModuleBuffer>, CString)>,
     tmp_path: TempDir,
     //symbols_below_threshold: &[String],
@@ -211,21 +147,12 @@ fn fat_lto(
     //   modules that are serialized in-memory.
     // * `in_memory` contains modules which are already parsed and in-memory,
     //   such as from multi-CGU builds.
-    //
-    // All of `cached_modules` (cached from previous incremental builds) can
-    // immediately go onto the `serialized_modules` modules list and then we can
-    // split the `modules` array into these two lists.
     let mut in_memory = Vec::new();
-    serialized_modules.extend(cached_modules.into_iter().map(|(buffer, wp)| {
-        info!("pushing cached module {:?}", wp.cgu_name);
-        (buffer, CString::new(wp.cgu_name).unwrap())
-    }));
     for module in modules {
         match module {
             FatLtoInput::InMemory(m) => in_memory.push(m),
             FatLtoInput::Serialized { name, buffer } => {
                 info!("pushing serialized module {:?}", name);
-                let buffer = SerializedModule::Local(buffer);
                 serialized_modules.push((buffer, CString::new(name).unwrap()));
             }
         }
@@ -356,12 +283,13 @@ impl ModuleBufferMethods for ModuleBuffer {
 /// can simply be copied over from the incr. comp. cache.
 pub(crate) fn run_thin(
     cgcx: &CodegenContext<GccCodegenBackend>,
+    each_linked_rlib_for_lto: &[PathBuf],
     modules: Vec<(String, ThinBuffer)>,
     cached_modules: Vec<(SerializedModule<ModuleBuffer>, WorkProduct)>,
 ) -> Result<(Vec<ThinModule<GccCodegenBackend>>, Vec<WorkProduct>), FatalError> {
     let dcx = cgcx.create_dcx();
     let dcx = dcx.handle();
-    let lto_data = prepare_lto(cgcx, dcx)?;
+    let lto_data = prepare_lto(cgcx, each_linked_rlib_for_lto, dcx)?;
     if cgcx.opts.cg.linker_plugin_lto.enabled() {
         unreachable!(
             "We should never reach this case if the LTO step \

src/back/write.rs

@@ -4,7 +4,6 @@ use gccjit::{Context, OutputKind};
 use rustc_codegen_ssa::back::link::ensure_removed;
 use rustc_codegen_ssa::back::write::{BitcodeSection, CodegenContext, EmitObj, ModuleConfig};
 use rustc_codegen_ssa::{CompiledModule, ModuleCodegen};
-use rustc_errors::DiagCtxtHandle;
 use rustc_fs_util::link_or_copy;
 use rustc_session::config::OutputType;
 use rustc_span::fatal_error::FatalError;
@@ -258,14 +257,6 @@ pub(crate) fn codegen(
     ))
 }
 
-pub(crate) fn link(
-    _cgcx: &CodegenContext<GccCodegenBackend>,
-    _dcx: DiagCtxtHandle<'_>,
-    mut _modules: Vec<ModuleCodegen<GccContext>>,
-) -> Result<ModuleCodegen<GccContext>, FatalError> {
-    unimplemented!();
-}
-
 pub(crate) fn save_temp_bitcode(
     cgcx: &CodegenContext<GccCodegenBackend>,
     _module: &ModuleCodegen<GccContext>,

src/builder.rs

@@ -34,6 +34,7 @@ use rustc_target::spec::{HasTargetSpec, HasX86AbiOpt, Target, X86Abi};
 
 use crate::common::{SignType, TypeReflection, type_is_pointer};
 use crate::context::CodegenCx;
+use crate::errors;
 use crate::intrinsic::llvm;
 use crate::type_of::LayoutGccExt;
 
@@ -1756,6 +1757,20 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
         call
     }
 
+    fn tail_call(
+        &mut self,
+        _llty: Self::Type,
+        _fn_attrs: Option<&CodegenFnAttrs>,
+        _fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
+        _llfn: Self::Value,
+        _args: &[Self::Value],
+        _funclet: Option<&Self::Funclet>,
+        _instance: Option<Instance<'tcx>>,
+    ) {
+        // FIXME: implement support for explicit tail calls like rustc_codegen_llvm.
+        self.tcx.dcx().emit_fatal(errors::ExplicitTailCallsUnsupported);
+    }
+
     fn zext(&mut self, value: RValue<'gcc>, dest_typ: Type<'gcc>) -> RValue<'gcc> {
         // FIXME(antoyo): this does not zero-extend.
         self.gcc_int_cast(value, dest_typ)

src/callee.rs

@@ -106,7 +106,7 @@ pub fn get_fn<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, instance: Instance<'tcx>)
                 // This is a monomorphization of a generic function.
                 if !(cx.tcx.sess.opts.share_generics()
                     || tcx.codegen_instance_attrs(instance.def).inline
-                        == rustc_attr_data_structures::InlineAttr::Never)
+                        == rustc_hir::attrs::InlineAttr::Never)
                 {
                     // When not sharing generics, all instances are in the same
                     // crate and have hidden visibility.

src/errors.rs

@@ -14,21 +14,12 @@ pub(crate) struct CopyBitcode {
     pub err: std::io::Error,
 }
 
-#[derive(Diagnostic)]
-#[diag(codegen_gcc_dynamic_linking_with_lto)]
-#[note]
-pub(crate) struct DynamicLinkingWithLTO;
-
-#[derive(Diagnostic)]
-#[diag(codegen_gcc_lto_disallowed)]
-pub(crate) struct LtoDisallowed;
-
-#[derive(Diagnostic)]
-#[diag(codegen_gcc_lto_dylib)]
-pub(crate) struct LtoDylib;
-
 #[derive(Diagnostic)]
 #[diag(codegen_gcc_lto_bitcode_from_rlib)]
 pub(crate) struct LtoBitcodeFromRlib {
     pub gcc_err: String,
 }
+
+#[derive(Diagnostic)]
+#[diag(codegen_gcc_explicit_tail_calls_unsupported)]
+pub(crate) struct ExplicitTailCallsUnsupported;