Mark ___asan_globals_registered as an exported symbol for LTO

Fixes #113404

Author: anforowicz

compiler/rustc_codegen_ssa/src/back/symbol_export.rs

@@ -265,6 +265,10 @@ fn exported_symbols_provider_local(
             externally_injected_weak_symbols.push("__msan_track_origins");
         }
     }
+    if tcx.sess.opts.unstable_opts.sanitizer.contains(SanitizerSet::ADDRESS) {
+        // Similar to profiling, preserve weak asan symbols during LTO.
+        externally_injected_weak_symbols.push("___asan_globals_registered");
+    }
     symbols.extend(externally_injected_weak_symbols.into_iter().map(|sym| {
         let exported_symbol = ExportedSymbol::NoDefId(SymbolName::new(tcx, sym));
         (

tests/codegen/sanitizer/address-sanitizer-globals-tracking.rs

@@ -0,0 +1,36 @@
+// Verifies that AddressSanitizer symbols show up as expected in LLVM IR
+// with -Zsanitizer (DO NOT SUBMIT: add ASAN (no LTO) and ASAN-LTO2 (lto=fat) tests).
+//
+// Notes about the `compile-flags` below:
+//
+// * The original issue only reproed with LTO - this is why this angle has
+//   extra test coverage via different `revisions`
+// * To observe the failure/repro at LLVM-IR level we need to use `staticlib`
+//   which necessitates `-C prefer-dynamic=false` - without the latter flag,
+//   we would have run into "cannot prefer dynamic linking when performing LTO".
+//
+// needs-sanitizer-address
+//
+// revisions:ASAN ASAN-LTO
+//[ASAN]     compile-flags: -Zsanitizer=address
+//[ASAN-LTO] compile-flags: -Zsanitizer=address -C prefer-dynamic=false -C lto
+
+#![crate_type="staticlib"]
+
+// The test below mimics `CACHED_POW10` from `library/core/src/num/flt2dec/strategy/grisu.rs` which
+// (because of incorrect handling of `___asan_globals_registered` during LTO) was incorrectly
+// reported as an ODR violation in https://crbug.com/1459233#c1.  Before this bug was fixed,
+// `___asan_globals_registered` would show up as `internal global i64`.
+//
+// See https://github.com/rust-lang/rust/issues/113404 for more discussion.
+//
+// CHECK: @___asan_globals_registered = common hidden global i64 0
+// CHECK: @__start_asan_globals = extern_weak hidden global i64
+// CHECK: @__stop_asan_globals = extern_weak hidden global i64
+#[no_mangle]
+pub static CACHED_POW10: [(u64, i16, i16); 4] = [
+    (0xe61acf033d1a45df, -1087, -308),
+    (0xab70fe17c79ac6ca, -1060, -300),
+    (0xff77b1fcbebcdc4f, -1034, -292),
+    (0xbe5691ef416bd60c, -1007, -284),
+];