DO NOT REPLY [Bug 18323] - Size of LDC_W's operand can be incorrect
| Newsgroups | gmane.comp.jakarta.bcel.devel |
|---|---|
| Message-ID | <[email protected]> |
DO NOT REPLY TO THIS EMAIL, BUT PLEASE POST YOUR BUG RELATED COMMENTS THROUGH THE WEB INTERFACE AVAILABLE AT <http://issues.apache.org/bugzilla/show_bug.cgi?id=18323>. ANY REPLY MADE TO THIS MESSAGE WILL NOT BE COLLECTED AND INSERTED IN THE BUG DATABASE. http://issues.apache.org/bugzilla/show_bug.cgi?id=18323 Size of LDC_W's operand can be incorrect ------- Additional Comments From [email protected] 2004-05-13 14:19 ------- One example is the JDK 1.4 compiled java.math.BigInteger. If you run: `javap -c java.math.BigInteger | grep ldc_w` you will find several examples of LDC_W operands with sub-256 indices: 401: ldc_w #268; //int 2147483647 1835: ldc_w #435; //String 0000000[..] 2691: ldc_w #259; //int 1162261467 2702: ldc_w #260; //int 1220703125 2709: ldc_w #247; //int 362797056 2716: ldc_w #267; //int 1977326743 2729: ldc_w #248; //int 387420489 2736: ldc_w #258; //int 1000000000 ... Without the above patch, a BCEL lifted and regenerated BigInteger will generate the following broken classfile: 434: ldc_w #268; //int 2147483647 1868: ldc_w #435; //String 0000000[..] 2724: ldc_w #259; //int 1162261467 2735: ldc_w #260; //int 1220703125 2742: ldc_w #63311; //BOGUS_TAG:100 <Incorrect CP index:63311> 2748: ldc_w #267; //int 1977326743 2761: ldc_w #63567; //BOGUS_TAG:100 <Incorrect CP index:63567> 2767: ldc_w #258; //int 1000000000 ... Note that 63311 = 247*256 + 79, and the instruction following the ldc_w is an iastore (opcode 79).