zip-library handling in Hotspot

[Baesken, Matthias]

Hello,   when  recently  working  on symbol  visibility issues   (in libzip and others too)  after the removal  of  mapfiles  across  jdk11 ,
I thought  it would be helpful  to  get  the detailed  information about  missing   libzip symbols  not only   for  ZIP_InflateFully    ("Corrupted ZIP library ZIP_InflateFully missing" )
But also  for the other needed symbols.
Do you think it makes sense to add this small change ( a suggested diff is below ) ?

Best regards, Matthias



d040975 at ld9385:/usr/work/d040975/open_jdk/jdk_2/jdk> hg diff
diff -r b2e74972c7d4 src/hotspot/share/classfile/classLoader.cpp
--- a/src/hotspot/share/classfile/classLoader.cpp       Wed Apr 25 13:54:11 2018 +0200
+++ b/src/hotspot/share/classfile/classLoader.cpp       Wed Apr 25 16:39:39 2018 +0200
@@ -1195,16 +1195,17 @@
   ZipInflateFully = CAST_TO_FN_PTR(ZipInflateFully_t, os::dll_lookup(handle, "ZIP_InflateFully"));
   Crc32        = CAST_TO_FN_PTR(Crc32_t, os::dll_lookup(handle, "ZIP_CRC32"));
-  // ZIP_Close is not exported on Windows in JDK5.0 so don't abort if ZIP_Close is NULL
   if (ZipOpen == NULL || FindEntry == NULL || ReadEntry == NULL ||
-      GetNextEntry == NULL || Crc32 == NULL) {
+      GetNextEntry == NULL || Crc32 == NULL || ZipInflateFully == NULL) {
+    if (ZipOpen == NULL) { tty->print_cr("Corrupted ZIP library at %s, ZIP_Open lookup failed", path); }
+    if (FindEntry == NULL) { tty->print_cr("Corrupted ZIP library at %s, ZIP_FindEntry lookup failed", path); }
+    if (ReadEntry == NULL) { tty->print_cr("Corrupted ZIP library at %s, ZIP_ReadEntry lookup failed", path); }
+    if (GetNextEntry == NULL) { tty->print_cr("Corrupted ZIP library at %s, ZIP_GetNextEntry lookup failed", path); }
+    if (Crc32 == NULL) { tty->print_cr("Corrupted ZIP library at %s, ZIP_CRC32 lookup failed", path); }
+    if (ZipInflateFully == NULL) { tty->print_cr("Corrupted ZIP library at %s, ZipInflateFully lookup failed", path); }
     vm_exit_during_initialization("Corrupted ZIP library", path);
   }
-  if (ZipInflateFully == NULL) {
-    vm_exit_during_initialization("Corrupted ZIP library ZIP_InflateFully missing", path);
-  }
-
   // Lookup canonicalize entry in libjava.dll
   void *javalib_handle = os::native_java_library();
   CanonicalizeEntry = CAST_TO_FN_PTR(canonicalize_fn_t, os::dll_lookup(javalib_handle, "Canonicalize"));