Cast unsigned values explicitly to avoid signed extension #5966
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| @@ -112,6 +112,6 @@ private long encode(ReferenceMapEncoder.OffsetIterator offsets) { | |||
| private void encodeRun(int offset, int refsCount) { | |||
| assert offset >= 0 && refsCount >= 0; | |||
| writeBuffer.putS4(offset); | |||
| writeBuffer.putU4(refsCount); | |||
| writeBuffer.putU4(Integer.toUnsignedLong(refsCount)); | |||
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I don's see how refsCount can ever get to anything remotely close to MAX_INT. What problem is this solving?
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If refsCount is an unsigned number, and it must be converted to a long for the function call, then the conversion needs to be a zero extension, not a signed extension.
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Maybe the assertion that refsCount >= 0 above is enough?
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I wouldn't call the assertion enough, but it surely will detect cases where refsCount is negative or huge, as long as assertions are explicitly enabled when running the code, and that is not the default. What I'm fixing here is the extension from int to long necessary at the call site to putU4(): that has to be a zero-extension, not a sign-extension.
...atevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/heap/HeapDumpFieldsMapFeature.java
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substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/reflect/AnnotationEncoder.java
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Cast unsigned values, stored in smaller types, to
longusing zero-extension instead of Java's default sign extension.