tests: [diag] print cxxabi type_info vtable resolution (si vs vmi)

Author: jcelerier

tests/jit-min/main.cpp

@@ -133,6 +133,26 @@ int main(int argc, char** argv)
   else
     fail("process-symbols generator", G.takeError());
 
+  // DIAG: how do the cxxabi type_info vtables resolve? si works (c06), vmi
+  // crashes (c10) -- compare the raw GetProcAddress value against the JIT lookup.
+  for(const char* sym :
+      {"_ZTVN10__cxxabiv117__class_type_infoE",
+       "_ZTVN10__cxxabiv120__si_class_type_infoE",
+       "_ZTVN10__cxxabiv121__vmi_class_type_infoE", "__dynamic_cast"})
+  {
+    void* gpa = sys::DynamicLibrary::SearchForAddressOfSymbol(sym);
+    errs() << "[diag] " << sym << "  GetProcAddr=" << gpa;
+    if(auto a = (*jit)->lookup(sym))
+      errs() << "  JIT=" << (void*)a->getValue();
+    else
+    {
+      consumeError(a.takeError());
+      errs() << "  JIT=NOTFOUND";
+    }
+    errs() << "\n";
+    errs().flush();
+  }
+
   // x86_64-w64-windows-gnu always lowers thread_local through emulated TLS
   // (__emutls_get_address); compiler-rt provides it but the host exe doesn't
   // export it, so DynamicLibrarySearchGenerator can't see it. Bind it directly.