diff -r ae0af9fb3dbb -r cba8afa5cfed src/hotspot/share/runtime/fieldType.cpp
--- a/src/hotspot/share/runtime/fieldType.cpp	Mon Oct 21 09:26:14 2019 -0700
+++ b/src/hotspot/share/runtime/fieldType.cpp	Mon Oct 21 13:13:16 2019 -0400
@@ -39,28 +39,28 @@
 // Check if it is a valid array signature
 bool FieldType::is_valid_array_signature(Symbol* sig) {
   assert(sig->utf8_length() > 1, "this should already have been checked");
-  assert(sig->char_at(0) == '[', "this should already have been checked");
+  assert(sig->char_at(0) == JVM_SIGNATURE_ARRAY, "this should already have been checked");
   // The first character is already checked
   int i = 1;
   int len = sig->utf8_length();
   // First skip all '['s
-  while(i < len - 1 && sig->char_at(i) == '[') i++;
+  while(i < len - 1 && sig->char_at(i) == JVM_SIGNATURE_ARRAY) i++;
 
   // Check type
   switch(sig->char_at(i)) {
-    case 'B': // T_BYTE
-    case 'C': // T_CHAR
-    case 'D': // T_DOUBLE
-    case 'F': // T_FLOAT
-    case 'I': // T_INT
-    case 'J': // T_LONG
-    case 'S': // T_SHORT
-    case 'Z': // T_BOOLEAN
+    case JVM_SIGNATURE_BYTE:
+    case JVM_SIGNATURE_CHAR:
+    case JVM_SIGNATURE_DOUBLE:
+    case JVM_SIGNATURE_FLOAT:
+    case JVM_SIGNATURE_INT:
+    case JVM_SIGNATURE_LONG:
+    case JVM_SIGNATURE_SHORT:
+    case JVM_SIGNATURE_BOOLEAN:
       // If it is an array, the type is the last character
       return (i + 1 == len);
-    case 'L':
+    case JVM_SIGNATURE_CLASS:
       // If it is an object, the last character must be a ';'
-      return sig->char_at(len - 1) == ';';
+      return sig->char_at(len - 1) == JVM_SIGNATURE_ENDCLASS;
   }
 
   return false;
@@ -71,7 +71,7 @@
   assert(basic_type(signature) == T_ARRAY, "must be array");
   int index = 1;
   int dim   = 1;
-  while (signature->char_at(index) == '[') {
+  while (signature->char_at(index) == JVM_SIGNATURE_ARRAY) {
     index++;
     dim++;
   }
@@ -80,7 +80,7 @@
   BasicType element_type = char2type(element[0]);
   if (element_type == T_OBJECT) {
     int len = (int)strlen(element);
-    assert(element[len-1] == ';', "last char should be a semicolon");
+    assert(element[len-1] == JVM_SIGNATURE_ENDCLASS, "last char should be a semicolon");
     element[len-1] = '\0';        // chop off semicolon
     fd._object_key = SymbolTable::new_symbol(element + 1);
   }