[asan darwin] Allow clients to implement __sanitizer_report_error_summary

`__sanitizer_report_error_summary` is declared `llvm/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_interface_internal.h` as being able to be overridden by the client. On darwin the sanitizer runtime uses this symbol to find references to the sanitizer libraries, so if you override it you end up with the error `=ERROR: Interceptors are not working. This may be because AddressSanitizer is loaded too late (e.g. via dlopen). Please launch the executable with:` at launch time.

Replace uses of `__sanitizer_report_error_summary` for finding the sanitizer libraries with using the address of a local function.

Reviewed By: yln, vitalybuka

Differential Revision: https://reviews.llvm.org/D144830

Author: Dave MacLachlan

compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp

@@ -989,7 +989,7 @@ static void VerifyInterceptorsWorking() {
   // "wrap_puts" within our own dylib.
   Dl_info info_puts, info_runtime;
   RAW_CHECK(dladdr(dlsym(RTLD_DEFAULT, "puts"), &info_puts));
-  RAW_CHECK(dladdr((void *)__sanitizer_report_error_summary, &info_runtime));
+  RAW_CHECK(dladdr((void *)&VerifyInterceptorsWorking, &info_runtime));
   if (internal_strcmp(info_puts.dli_fname, info_runtime.dli_fname) != 0) {
     Report(
         "ERROR: Interceptors are not working. This may be because %s is "
@@ -1039,7 +1039,7 @@ static void StripEnv() {
     return;
 
   Dl_info info;
-  RAW_CHECK(dladdr((void *)__sanitizer_report_error_summary, &info));
+  RAW_CHECK(dladdr((void *)&StripEnv, &info));
   const char *dylib_name = StripModuleName(info.dli_fname);
   bool lib_is_in_env = internal_strstr(dyld_insert_libraries, dylib_name);
   if (!lib_is_in_env)

compiler-rt/test/asan/TestCases/report_error_summary.cpp

@@ -0,0 +1,17 @@
+// RUN: %clangxx_asan -O0 %s -o %t && not %run %t 2>&1 | FileCheck %s
+
+#include <stdio.h>
+
+extern "C" void __sanitizer_report_error_summary(const char *summary) {
+  fprintf(stderr, "test_report_error_summary\n", summary);
+  // CHECK: test_report_error_summary
+  fflush(stderr);
+}
+
+char *x;
+
+int main() {
+  x = new char[20];
+  delete[] x;
+  return x[0];
+}