Fix #64153

src/librustc_codegen_llvm/back/archive.rs

@@ -9,7 +9,9 @@ use std::str;
 
 use crate::llvm::archive_ro::{ArchiveRO, Child};
 use crate::llvm::{self, ArchiveKind};
-use rustc_codegen_ssa::{METADATA_FILENAME, RLIB_BYTECODE_EXTENSION};
+use rustc_codegen_ssa::{
+ METADATA_FILENAME, RLIB_BYTECODE_EXTENSION, looks_like_rust_object_file
+};
 use rustc_codegen_ssa::back::archive::{ArchiveBuilder, find_library};
 use rustc::session::Session;
 use syntax::symbol::Symbol;
@@ -141,7 +143,7 @@ impl<'a> ArchiveBuilder<'a> for LlvmArchiveBuilder<'a> {
  }
 
  // Don't include Rust objects if LTO is enabled
- if lto && fname.starts_with(&obj_start) && fname.ends_with(".o") {
+ if lto && looks_like_rust_object_file(fname) {
  return true
  }
 

src/librustc_codegen_ssa/back/link.rs

@@ -3,7 +3,7 @@
 
 use rustc::session::{Session, filesearch};
 use rustc::session::config::{
- self, RUST_CGU_EXT, DebugInfo, OutputFilenames, OutputType, PrintRequest, Sanitizer
+ self, DebugInfo, OutputFilenames, OutputType, PrintRequest, Sanitizer
 };
 use rustc::session::search_paths::PathKind;
 use rustc::middle::dependency_format::Linkage;
@@ -15,7 +15,8 @@ use rustc_fs_util::fix_windows_verbatim_for_gcc;
 use rustc_target::spec::{PanicStrategy, RelroLevel, LinkerFlavor};
 use syntax::symbol::Symbol;
 
-use crate::{METADATA_FILENAME, RLIB_BYTECODE_EXTENSION, CrateInfo, CodegenResults};
+use crate::{METADATA_FILENAME, RLIB_BYTECODE_EXTENSION, CrateInfo,
+ looks_like_rust_object_file, CodegenResults};
 use super::archive::ArchiveBuilder;
 use super::command::Command;
 use super::linker::Linker;
@@ -1549,23 +1550,9 @@ fn add_upstream_rust_crates<'a, B: ArchiveBuilder<'a>>(
  let canonical = f.replace("-", "_");
  let canonical_name = name.replace("-", "_");
 
- // Look for `.rcgu.o` at the end of the filename to conclude
- // that this is a Rust-related object file.
- fn looks_like_rust(s: &str) -> bool {
- let path = Path::new(s);
- let ext = path.extension().and_then(|s| s.to_str());
- if ext != Some(OutputType::Object.extension()) {
- return false
- }
- let ext2 = path.file_stem()
- .and_then(|s| Path::new(s).extension())
- .and_then(|s| s.to_str());
- ext2 == Some(RUST_CGU_EXT)
- }
-
  let is_rust_object =
  canonical.starts_with(&canonical_name) &&
- looks_like_rust(&f);
+ looks_like_rust_object_file(&f);
 
  // If we've been requested to skip all native object files
  // (those not generated by the rust compiler) then we can skip

src/librustc_codegen_ssa/lib.rs

@@ -22,9 +22,9 @@
 #[macro_use] extern crate rustc;
 #[macro_use] extern crate syntax;
 
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use rustc::dep_graph::WorkProduct;
-use rustc::session::config::{OutputFilenames, OutputType};
+use rustc::session::config::{OutputFilenames, OutputType, RUST_CGU_EXT};
 use rustc::middle::lang_items::LangItem;
 use rustc::hir::def_id::CrateNum;
 use rustc::ty::query::Providers;
@@ -62,6 +62,7 @@ pub struct ModuleCodegen<M> {
 pub const METADATA_FILENAME: &str = "rust.metadata.bin";
 pub const RLIB_BYTECODE_EXTENSION: &str = "bc.z";
 
+
 impl<M> ModuleCodegen<M> {
  pub fn into_compiled_module(self,
  emit_obj: bool,
@@ -166,3 +167,22 @@ pub fn provide_extern(providers: &mut Providers<'_>) {
  crate::back::symbol_export::provide_extern(providers);
  crate::base::provide_both(providers);
 }
+
+/// Checks if the given filename ends with the `.rcgu.o` extension that `rustc`
+/// uses for the object files it generates.
+pub fn looks_like_rust_object_file(filename: &str) -> bool {
+ let path = Path::new(filename);
+ let ext = path.extension().and_then(|s| s.to_str());
+ if ext != Some(OutputType::Object.extension()) {
+ // The file name does not end with ".o", so it can't be an object file.
+ return false
+ }
+
+ // Strip the ".o" at the end
+ let ext2 = path.file_stem()
+ .and_then(|s| Path::new(s).extension())
+ .and_then(|s| s.to_str());
+
+ // Check if the "inner" extension
+ ext2 == Some(RUST_CGU_EXT)
+}

src/test/run-make-fulldeps/issue-64153/Makefile

@@ -0,0 +1,26 @@
+-include ../tools.mk
+
+# `llvm-objdump`'s output looks different on windows than on other platforms.
+# It should be enough to check on Unix platforms, so:
+# ignore-windows
+
+# Staticlibs don't include Rust object files from upstream crates if the same
+# code was already pulled into the lib via LTO. However, the bug described in
+# https://github.com/rust-lang/rust/issues/64153 lead to this exclusion not
+# working properly if the upstream crate was compiled with an explicit filename
+# (via `-o`).
+#
+# This test makes sure that functions defined in the upstream crates do not
+# appear twice in the final staticlib when listing all the symbols from it.
+
+all:
+ $(RUSTC) --crate-type rlib upstream.rs -o $(TMPDIR)/libupstream.rlib -Ccodegen-units=1
+ $(RUSTC) --crate-type staticlib downstream.rs -Clto -Ccodegen-units=1 -o $(TMPDIR)/libdownstream.a
+ # Dump all the symbols from the staticlib into `syms`
+ "$(LLVM_BIN_DIR)"/llvm-objdump -t $(TMPDIR)/libdownstream.a > $(TMPDIR)/syms
+ # Count the global instances of `issue64153_test_function`. There'll be 2
+ # if the `upstream` object file got erronously included twice.
+ # The line we are testing for with the regex looks something like:
+ # 0000000000000000 g F .text.issue64153_test_function 00000023 issue64153_test_function
+ grep -c -e "[[:space:]]g[[:space:]]*F[[:space:]].*issue64153_test_function" $(TMPDIR)/syms > $(TMPDIR)/count
+ [ "$$(cat $(TMPDIR)/count)" -eq "1" ]

src/test/run-make-fulldeps/issue-64153/downstream.rs

@@ -0,0 +1,6 @@
+extern crate upstream;
+
+#[no_mangle]
+pub extern "C" fn foo() {
+ print!("1 + 1 = {}", upstream::issue64153_test_function(1));
+}

src/test/run-make-fulldeps/issue-64153/upstream.rs

@@ -0,0 +1,6 @@
+// Make this function extern "C", public, and no-mangle, so that it gets
+// exported from the downstream staticlib.
+#[no_mangle]
+pub extern "C" fn issue64153_test_function(x: u32) -> u32 {
+ x + 1
+}