Rollup merge of #145965 - bjorn3:sanitize_symbol_export_improvements, r=lqd

Move exporting of profiler and sanitizer symbols to the LLVM backend

Only the LLVM backend needs those specific symbols exported and it only needs them to be exported for LTO, not from cdylibs in general.

1 files changed, 32 insertions, 0 deletions

diff --git a/compiler/rustc_codegen_llvm/src/back/lto.rs b/compiler/rustc_codegen_llvm/src/back/lto.rs
index d85f432702c..fc38c4f3e51 100644
--- a/compiler/rustc_codegen_llvm/src/back/lto.rs
+++ b/compiler/rustc_codegen_llvm/src/back/lto.rs
@@ -15,6 +15,7 @@ use rustc_codegen_ssa::{ModuleCodegen, ModuleKind, looks_like_rust_object_file};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::memmap::Mmap;
 use rustc_errors::DiagCtxtHandle;
+use rustc_hir::attrs::SanitizerSet;
 use rustc_middle::bug;
 use rustc_middle::dep_graph::WorkProduct;
 use rustc_session::config::{self, Lto};
@@ -42,6 +43,37 @@ fn prepare_lto(
         .map(|symbol| CString::new(symbol.to_owned()).unwrap())
         .collect::<Vec<CString>>();
 
+    if cgcx.regular_module_config.instrument_coverage
+        || cgcx.regular_module_config.pgo_gen.enabled()
+    {
+        // These are weak symbols that point to the profile version and the
+        // profile name, which need to be treated as exported so LTO doesn't nix
+        // them.
+        const PROFILER_WEAK_SYMBOLS: [&CStr; 2] =
+            [c"__llvm_profile_raw_version", c"__llvm_profile_filename"];
+
+        symbols_below_threshold.extend(PROFILER_WEAK_SYMBOLS.iter().map(|&sym| sym.to_owned()));
+    }
+
+    if cgcx.regular_module_config.sanitizer.contains(SanitizerSet::MEMORY) {
+        let mut msan_weak_symbols = Vec::new();
+
+        // Similar to profiling, preserve weak msan symbol during LTO.
+        if cgcx.regular_module_config.sanitizer_recover.contains(SanitizerSet::MEMORY) {
+            msan_weak_symbols.push(c"__msan_keep_going");
+        }
+
+        if cgcx.regular_module_config.sanitizer_memory_track_origins != 0 {
+            msan_weak_symbols.push(c"__msan_track_origins");
+        }
+
+        symbols_below_threshold.extend(msan_weak_symbols.into_iter().map(|sym| sym.to_owned()));
+    }
+
+    // Preserve LLVM-injected, ASAN-related symbols.
+    // See also https://github.com/rust-lang/rust/issues/113404.
+    symbols_below_threshold.push(c"___asan_globals_registered".to_owned());
+
     // __llvm_profile_counter_bias is pulled in at link time by an undefined reference to
     // __llvm_profile_runtime, therefore we won't know until link time if this symbol
     // should have default visibility.