[Sanitizers][Darwin] In DlAddrSymbolizer, return only the module file name instead of the comlpete module path during symbolication.

[usama54321]

Summary

There is an inconsistency between the stack traces of AtosSymbolizer and DlAddrSymbolizer. AtosSymbolizer removes the module file path prefix from the module file name during symbolication in the function ParseCommandOutput. This patch makes DlAddrSymbolizer consistent with this behavior.

rdar://108858834

[thetruestblue]

A little surprised we don't have "basename" utility functionality anywhere (looks like fuzzer has it). But this looks fine/clean to me.

[delcypher]

compiler-rt/test/sanitizer_common/TestCases/Darwin/symbolizer-file-name-dladdr.cpp

9

Is this test case sufficient? It looks like it pass even without your change due to the {{.*}}

[thetruestblue]

compiler-rt/test/sanitizer_common/TestCases/Darwin/symbolizer-file-name-dladdr.cpp

9

I had this thought too, but I think the open paren is where the file path usually is... so I think this works.

compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_mac.cpp

bool DlAddrSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
   // sym_addr` so only compute the offset when this holds. Failure to find the
   // function offset is not treated as a failure because it might still be
   // possible to get the symbol name.
   uptr sym_addr = reinterpret_cast<uptr>(info.dli_saddr);
   if (addr >= sym_addr) {
     stack->info.function_offset = addr - sym_addr;
   }
 
+  if (info.dli_fname) {
+    if (auto *last_occurence = internal_strrchr(info.dli_fname, '/')) {
+      stack->info.module = internal_strdup(last_occurence + 1);
+    }
+  }
+
   const char *demangled = DemangleSwiftAndCXX(info.dli_sname);
   if (!demangled) return false;
   stack->info.function = internal_strdup(demangled);
   return true;
 }
 
 bool DlAddrSymbolizer::SymbolizeData(uptr addr, DataInfo *datainfo) {
   Dl_info info;

compiler-rt/test/sanitizer_common/TestCases/Darwin/symbolizer-file-name-dladdr.cpp

+// RUN: %clangxx %s -O0 -o %t
+// RUN: %env_tool_opts=external_symbolizer_path= %run %t 2>&1 | FileCheck %s
+#include <sanitizer/common_interface_defs.h>
+#include <stdio.h>
+
+int main() {
+  //CHECK: #0{{.*}}
+  //CHECK: #1{{.*}}(symbolizer-file-name-dladdr.cpp.tmp
+  __sanitizer_print_stack_trace();
+  return 0;
+}