76 inline int Backtrace::merge_bci_and_version(int bci, int version) {

    77   // only store u2 for version, checking for overflow.

    78   if (version > USHRT_MAX || version < 0) version = USHRT_MAX;

    79   assert((jushort)bci == bci, "bci should be short");

    80   return build_int_from_shorts(version, bci);

    81 }

    82 

    83 inline int Backtrace::merge_mid_and_cpref(int mid, int cpref) {

    84   // only store u2 for mid and cpref, checking for overflow.

    85   assert((jushort)mid == mid, "mid should be short");

    86   assert((jushort)cpref == cpref, "cpref should be short");

    87   return build_int_from_shorts(cpref, mid);

    88 }

    89 

    90 inline int Backtrace::bci_at(unsigned int merged) {

    91   return extract_high_short_from_int(merged);

    92 }

    93 

    94 inline int Backtrace::version_at(unsigned int merged) {

    95   return extract_low_short_from_int(merged);

    96 }

    97 

    98 inline int Backtrace::mid_at(unsigned int merged) {

    99   return extract_high_short_from_int(merged);

   100 }

   101 

   102 inline int Backtrace::cpref_at(unsigned int merged) {

   103   return extract_low_short_from_int(merged);

   104 }

   105 

   106 inline int Backtrace::get_line_number(const methodHandle& method, int bci) {

   107   int line_number = 0;

   108   if (method->is_native()) {

   109     // Negative value different from -1 below, enabling Java code in

   110     // class java.lang.StackTraceElement to distinguish "native" from

   111     // "no LineNumberTable".  JDK tests for -2.

   112     line_number = -2;

   113   } else {

   114     // Returns -1 if no LineNumberTable, and otherwise actual line number

   115     line_number = method->line_number_from_bci(bci);

   116     if (line_number == -1 && ShowHiddenFrames) {

   117       line_number = bci + 1000000;

   118     }

   119   }

   120   return line_number;

   121 }

   122 

   123 /*

   124  * Returns the source file name of a given InstanceKlass and version

   125  */

   126 inline Symbol* Backtrace::get_source_file_name(InstanceKlass* holder, int version) {

   127   // Find the specific ik version that contains this source_file_name_index

   128   // via the previous versions list, but use the current version's

   129   // constant pool to look it up.  The previous version's index has been

   130   // merged for the current constant pool.

   131   InstanceKlass* ik = holder->get_klass_version(version);

   132   // This version has been cleaned up.

   133   if (ik == NULL) return NULL;

   134   int source_file_name_index = ik->source_file_name_index();

   135   return (source_file_name_index == 0) ?

   136       (Symbol*)NULL : holder->constants()->symbol_at(source_file_name_index);

   137 }

   138