8365940: Misleading macro in jvm_md.h:57

[matias9927]

The macro JVM_MAXPATHLEN should expand to the result of MAXPATHLEN + 1 as the original result may lead to a different value when using the macro as part of an expression. Verified with tier 1-5 tests.

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Issue

• JDK-8365940: Misleading macro in jvm_md.h:57 (Bug - P3)

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• David Holmes (@dholmes-ora - Reviewer)

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8365940: Misleading macro in jvm_md.h:57

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[dholmes-ora]

Trivially fine. Thanks

[kimbarrett]

Per the comment immediately preceeding the definition, JVM_MAXPATHLEN exists
to support "JVM and the rest of JDK are built on different Linux releases". We
used to have the JVM and the rest of the JDK separable, and could use
(somewhat) different versions of them together. But that model was elminated
years ago.

All uses of JVM_MAXPATHLEN are in HotSpot. (There are also
unused definitions of that name in
jdk.hotspot.agent/share/native/libsaproc/sadis.c.)

Looking around, there are many uses of MAXPATHLEN in HotSpot. If we really
need JVM_MAXPATHLEN, how sure are we that all of those uses of MAXPATHLEN are
okay?

So maybe it would be better to just remove JVM_MAXPATHLEN and use MAXPATHLEN
everywhere.

[matias9927]

Thanks for finding that, I was also unsure whether or not the comment above was still valid today. I agree that if JVM_MAXPATHLEN is actually unneeded it can be removed.