src/hotspot/share/ci/ciReplay.cpp

rev 53818 : 8219642: ciReplay loads wrong data when MethodData size changes
Reviewed-by:

*** 271,289 ****
    }
  
    // Parse a sequence of raw data encoded as bytes and return the
    // resulting data.
    char* parse_data(const char* tag, int& length) {
!     if (!parse_tag_and_count(tag, length)) {
        return NULL;
      }
  
!     char * result = NEW_RESOURCE_ARRAY(char, length);
!     for (int i = 0; i < length; i++) {
        int val = parse_int("data");
        result[i] = val;
      }
      return result;
    }
  
    // Parse a standard chunk of data emitted as:
    //   'tag' <length> # # ...
--- 271,316 ----
    }
  
    // Parse a sequence of raw data encoded as bytes and return the
    // resulting data.
    char* parse_data(const char* tag, int& length) {
!     int read_size = 0;
!     if (!parse_tag_and_count(tag, read_size)) {
        return NULL;
      }
  
!     int actual_size = sizeof(MethodData);
!     char *result = NEW_RESOURCE_ARRAY(char, actual_size);
!     int i = 0;
!     if (read_size != actual_size) {
!       tty->print_cr("Warning: ciMethodData parsing sees MethodData size %i in file, current is %i", read_size,
!                     actual_size);
!       // Replay serializes the entire MethodData, but the data is at the end.
!       // If the MethodData instance size has changed, we can pad or truncate in the beginning
!       int padding = actual_size - read_size;
!       if (padding > 0) {
!         // pad missing data with zeros
!         tty->print_cr("- Padding MethodData");
!         for (; i < padding; i++) {
!           result[i] = 0;
!         }
!       } else if (padding < 0) {
!         // drop some data
!         tty->print_cr("- Truncating MethodData");
!         for (int j = 0; j < -padding; j++) {
!           int val = parse_int("data");
!           // discard val
!         }
!       }
!     }
! 
!     assert(i < actual_size, "At least some data must remain to be copied");
!     for (; i < actual_size; i++) {
        int val = parse_int("data");
        result[i] = val;
      }
+     length = actual_size;
      return result;
    }
  
    // Parse a standard chunk of data emitted as:
    //   'tag' <length> # # ...