[compiler-rt] [TSan] fix crash when symbolize on darwin platforms (PR #99441)

[via llvm-commits]

https://github.com/pudge62 created https://github.com/llvm/llvm-project/pull/99441

The `dli_sname` filed in `Dl_info` may be `NULL`, which could cause a crash

>From 87be878a3588ff3fa466805e3305e8cb3fa55ef1 Mon Sep 17 00:00:00 2001
From: pudge62 <70063806+pudge62 at users.noreply.github.com>
Date: Thu, 18 Jul 2024 15:15:26 +0800
Subject: [PATCH] [TSan] fix crash when symbolize on darwin platforms

The `dli_sname` filed in `Dl_info` may be `NULL`, which could cause a crash
---
 compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_mac.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_mac.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_mac.cpp
index f1cc0b5e1e8ac..88536fc4e6222 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_mac.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_mac.cpp
@@ -30,7 +30,7 @@ namespace __sanitizer {
 bool DlAddrSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
   Dl_info info;
   int result = dladdr((const void *)addr, &info);
-  if (!result) return false;
+  if (!result || !info.dli_sname) return false;
 
   // Compute offset if possible. `dladdr()` doesn't always ensure that `addr >=
   // sym_addr` so only compute the offset when this holds. Failure to find the
@@ -51,7 +51,7 @@ bool DlAddrSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
 bool DlAddrSymbolizer::SymbolizeData(uptr addr, DataInfo *datainfo) {
   Dl_info info;
   int result = dladdr((const void *)addr, &info);
-  if (!result) return false;
+  if (!result || !info.dli_sname) return false;
   const char *demangled = DemangleSwiftAndCXX(info.dli_sname);
   if (!demangled)
     demangled = info.dli_sname;