src/hotspot/share/interpreter/bytecodeUtils.cpp

rev 56281 : 8218628: Add detailed message to NullPointerException describing what is null.
Summary: This is the implementation of JEP 358: Helpful NullPointerExceptions.
Reviewed-by: coleenp
rev 56283 : [mq]: fixes_review_of_16.patch

@@ -29,10 +29,11 @@
 #include "interpreter/bytecodeUtils.hpp"
 #include "memory/resourceArea.hpp"
 #include "runtime/signature.hpp"
 #include "runtime/safepointVerifiers.hpp"
 #include "utilities/events.hpp"
+#include "utilities/ostream.hpp"
 
 class SimulatedOperandStack;
 class ExceptionMessageBuilder;
 
 // The entries of a SimulatedOperandStack. They carry the analysis

@@ -209,15 +210,12 @@
 
   // Prints a string describing the failed action.
   void print_NPE_failed_action(outputStream *os, int bci);
 };
 
-
-/*
- * Prints the name of the method that is described at constant pool
- * index cp_index in the constant pool of method 'method'.
- */
+// Prints the name of the method that is described at constant pool
+// index cp_index in the constant pool of method 'method'.
 static void print_method_name(outputStream *os, Method* method, int cp_index) {
   ConstantPool* cp  = method->constants();
   Symbol* klass     = cp->klass_ref_at_noresolve(cp_index);
   Symbol* name      = cp->name_ref_at(cp_index);
   Symbol* signature = cp->signature_ref_at(cp_index);

@@ -225,25 +223,21 @@
   os->print("%s.%s(", klass->as_klass_external_name(), name->as_C_string());
   signature->print_as_signature_external_parameters(os);
   os->print(")");
 }
 
-/*
- * Prints the name of the field that is described at constant pool
- * index cp_index in the constant pool of method 'method'.
- */
+// Prints the name of the field that is described at constant pool
+// index cp_index in the constant pool of method 'method'.
 static void print_field_and_class(outputStream *os, Method* method, int cp_index) {
   ConstantPool* cp = method->constants();
   Symbol* klass    = cp->klass_ref_at_noresolve(cp_index);
   Symbol *name     = cp->name_ref_at(cp_index);
   os->print("%s.%s", klass->as_klass_external_name(), name->as_C_string());
 }
 
-/*
- * Returns the name of the field that is described at constant pool
- * index cp_index in the constant pool of method 'method'.
- */
+// Returns the name of the field that is described at constant pool
+// index cp_index in the constant pool of method 'method'.
 static char const* get_field_name(Method* method, int cp_index) {
   Symbol* name = method->constants()->name_ref_at(cp_index);
   return name->as_C_string();
 }
 

@@ -386,12 +380,14 @@
 }
 
 ExceptionMessageBuilder::ExceptionMessageBuilder(Method* method, int bci) :
                     _method(method), _nr_of_entries(0),
                     _added_one(true), _all_processed(false) {
-  ConstMethod* const_method = method->constMethod();
+  assert(bci >= 0, "BCI too low");
+  assert(bci < get_size(), "BCI too large");
 
+  ConstMethod* const_method = method->constMethod();
   const int len = const_method->code_size();
 
   _stacks = new GrowableArray<SimulatedOperandStack*> (len+1);
 
   for (int i = 0; i <= len; ++i) {

@@ -1356,10 +1352,11 @@
       SystemDictionary::reflect_NativeConstructorAccessorImpl_klass()) {
     return false;
   }
 
   // Analyse the bytecodes.
+  ResourceMark rm;
   ExceptionMessageBuilder emb(method, bci);
 
   // The slot of the operand stack that contains the null reference.
   // Also checks for NPE explicitly constructed and returns -2.
   int slot = emb.get_NPE_null_slot(bci);