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

*** 29,38 ****
--- 29,39 ----
  #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
*** 209,223 ****
  
    // 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'.
!  */
  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);
--- 210,221 ----
  
    // 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'.
  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);
*** 225,249 ****
    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'.
!  */
  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'.
!  */
  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();
  }
  
--- 223,243 ----
    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'.
  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'.
  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();
  }
  
*** 386,397 ****
  }
  
  ExceptionMessageBuilder::ExceptionMessageBuilder(Method* method, int bci) :
                      _method(method), _nr_of_entries(0),
                      _added_one(true), _all_processed(false) {
!   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) {
--- 380,393 ----
  }
  
  ExceptionMessageBuilder::ExceptionMessageBuilder(Method* method, int bci) :
                      _method(method), _nr_of_entries(0),
                      _added_one(true), _all_processed(false) {
!   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) {
*** 1356,1365 ****
--- 1352,1362 ----
        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);