fix LTO archive linking

Author: IntegralPilot

.github/workflows/ci.yml

@@ -9,8 +9,12 @@ on:
 
 jobs:
   typst:
-    name: Typst documents (Ubuntu)
+    name: Typst documents (${{ matrix.profile }}, Ubuntu)
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        profile: [debug, release]
     timeout-minutes: 45
     permissions:
       contents: read
@@ -71,13 +75,13 @@ jobs:
       run: python build.py ci
 
     - name: Compile and render Typst documents
-      run: python tests/typst/run.py
+      run: python tests/typst/run.py ${{ matrix.profile == 'release' && '--release' || '' }}
 
     - name: Upload Typst output and diagnostics
       if: always()
       uses: actions/upload-artifact@v4
       with:
-        name: typst-documents
+        name: typst-documents-${{ matrix.profile }}
         path: target/typst/reports/
         if-no-files-found: warn
 

src/archive.rs

@@ -0,0 +1,56 @@
+//! Keep JVM payloads when rustc filters native objects out of LTO dependencies.
+use rustc_codegen_ssa::back::archive::{
+    AddArchiveKind, ArArchiveBuilder, ArchiveBuilder, ArchiveBuilderBuilder, ArchiveEntryKind,
+    ArchiveSymbols, DEFAULT_OBJECT_READER, ImportLibraryItem,
+};
+use rustc_session::Session;
+use std::{io, path::Path};
+
+pub(super) struct RlibArchiveBuilder;
+
+impl ArchiveBuilderBuilder for RlibArchiveBuilder {
+    fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder + 'a> {
+        Box::new(JvmArchiveBuilder(ArArchiveBuilder::new(
+            sess,
+            &DEFAULT_OBJECT_READER,
+        )))
+    }
+
+    fn create_dll_import_lib(
+        &self,
+        _sess: &Session,
+        _lib_name: &str,
+        _dll_imports: Vec<ImportLibraryItem>,
+        _tmpdir: &Path,
+    ) {
+        unimplemented!("creating dll imports is not supported");
+    }
+}
+
+struct JvmArchiveBuilder<'a>(ArArchiveBuilder<'a>);
+
+impl ArchiveBuilder for JvmArchiveBuilder<'_> {
+    fn add_file(&mut self, path: &Path, kind: ArchiveEntryKind) {
+        self.0.add_file(path, kind);
+    }
+
+    fn add_archive(&mut self, path: &Path, kind: AddArchiveKind<'_>) -> io::Result<()> {
+        match kind {
+            AddArchiveKind::Rlib(cache, skip) => {
+                // Native LTO has already consumed upstream Rust objects. JVM
+                // bundles are instead merged by java-linker and must reach it,
+                // even when the Cargo profile requests thin or fat LTO.
+                let skip = |name: &str, kind| {
+                    let jvm_payload = name.ends_with(".jvmbundle") || name.ends_with(".jvmsymbols");
+                    !jvm_payload && skip(name, kind)
+                };
+                self.0.add_archive(path, AddArchiveKind::Rlib(cache, &skip))
+            }
+            AddArchiveKind::Other => self.0.add_archive(path, kind),
+        }
+    }
+
+    fn build(self: Box<Self>, output: &Path, symbols: Option<ArchiveSymbols>) -> bool {
+        Box::new(self.0).build(output, symbols)
+    }
+}

src/lib.rs

@@ -59,7 +59,6 @@ macro_rules! log {
 
 use crate::lower1::context::Definitions;
 use oomir::Type;
-use rustc_codegen_ssa::back::archive::{ArArchiveBuilder, ArchiveBuilder, ArchiveBuilderBuilder};
 use rustc_codegen_ssa::{
     CompiledModule, CompiledModules, CrateInfo, ModuleKind, traits::CodegenBackend,
 };
@@ -125,6 +124,8 @@ fn combine_class_bundles(path: &Path, bundles: &[(String, PathBuf)]) -> std::io:
 
 mod allocator_shims;
 use allocator_shims::emit_allocator_shims;
+mod archive;
+use archive::RlibArchiveBuilder;
 
 fn lower_mono_function<'tcx>(
     tcx: TyCtxt<'tcx>,
@@ -667,22 +668,3 @@ use std::alloc::Layout;
 pub fn custom_alloc_error_hook(layout: Layout) {
     panic!("Memory allocation failed: {} bytes", layout.size());
 }
-
-struct RlibArchiveBuilder;
-impl ArchiveBuilderBuilder for RlibArchiveBuilder {
-    fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder + 'a> {
-        Box::new(ArArchiveBuilder::new(
-            sess,
-            &rustc_codegen_ssa::back::archive::DEFAULT_OBJECT_READER,
-        ))
-    }
-    fn create_dll_import_lib(
-        &self,
-        _sess: &Session,
-        _lib_name: &str,
-        _dll_imports: std::vec::Vec<rustc_codegen_ssa::back::archive::ImportLibraryItem>,
-        _tmpdir: &Path,
-    ) {
-        unimplemented!("creating dll imports is not supported");
-    }
-}

tests/multicrate/lto/Cargo.lock

@@ -0,0 +1,15 @@
+[package]
+name = "lto"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+lto_provider = { path = "provider" }
+
+# Exercise both modes: dependency class bundles must survive either LTO flag.
+[profile.dev]
+lto = "thin"
+
+[profile.release]
+lto = "fat"
+codegen-units = 1

tests/multicrate/lto/Cargo.toml

@@ -0,0 +1,4 @@
+[package]
+name = "lto_provider"
+version = "0.1.0"
+edition = "2024"

tests/multicrate/lto/provider/Cargo.toml

@@ -0,0 +1,4 @@
+#[inline(never)]
+pub fn answer() -> u32 {
+    std::hint::black_box(42)
+}

tests/multicrate/lto/provider/src/lib.rs

@@ -0,0 +1,5 @@
+fn main() {
+    // Neither the dependency body nor std::env is defined in this crate.
+    assert_eq!(lto_provider::answer(), 42);
+    assert!(!std::env::args().next().unwrap().is_empty());
+}

tests/multicrate/lto/src/main.rs

@@ -83,6 +83,7 @@ def main() -> int:
     parser.add_argument("--target-dir", type=Path, default=ROOT / "target/typst/build")
     parser.add_argument("--reports", type=Path, default=ROOT / "target/typst/reports")
     parser.add_argument("--timeout", type=float, default=180)
+    parser.add_argument("--release", action="store_true", help="Build with Cargo's release profile")
     parser.add_argument("--case", action="append", choices=CASES, dest="cases")
     args = parser.parse_args()
     if args.timeout <= 0:
@@ -97,7 +98,8 @@ def main() -> int:
         parser.error(f"missing Typst reporter checkout: {source}")
     # Cargo does not track changes to the backend library or bundled runtime.
     # Rebuild JVM artifacts each time, retaining compiled host build tools.
-    jvm_target = target / TARGET_SPEC.stem
+    profile = "release" if args.release else "debug"
+    jvm_target = target / TARGET_SPEC.stem / profile
     if jvm_target.exists():
         shutil.rmtree(jvm_target)
     reports.mkdir(parents=True, exist_ok=True)
@@ -120,13 +122,16 @@ def main() -> int:
         "-Zjson-target-spec", "-Zbuild-std=std,panic_unwind",
         "-Zbuild-std-features=panic-unwind", "--target-dir", str(target), "-j2",
     ]
+    if args.release:
+        command.append("--release")
     revision = subprocess.check_output(
         ["git", "rev-parse", "HEAD"], cwd=source, text=True
     ).strip()
     report = {
         "passed": False,
         "source_revision": revision,
         "toolchain": toolchain,
+        "profile": profile,
         "build_command": command,
     }
     original = entry.read_bytes()
@@ -147,7 +152,7 @@ def main() -> int:
             print((reports / "build.stderr.log").read_text(), file=sys.stderr)
             return 1
 
-        jar = target / "jvm-unknown-jvm/debug/typst-shared.jar"
+        jar = jvm_target / "typst-shared.jar"
         report["documents"] = {
             case: run_document(jar, case, reports, args.timeout)
             for case in args.cases or CASES