Copy local signature from MethodHandleNatives.resolve

[theresa-m]

For the case mentioned in #20189 (comment) sig1 in j9bcv_checkClassLoadingConstraintsForSignature should be copied but sig2 does not need to be copied. I added an additional boolean for each signature and it is only set to false if the signature is found in a class memory segment.

Related to: #20189

[hangshao0]

This trace point is level 5, which is not enabled by default.
We cannot change an existing trace point like this. It could cause problems parsing snap trace file generated by an older build that does not have this change.

Instead of changing this trace point, maybe you can add a new function like the following to set copyUTF1 and copyUTF2

static void 
findNamesInSegments(validateArgs (J9VMThread *vmThread, U_8 *name1, U_8 *name2, UDATA *name1Found, UDATA *name2Found) 
{
	J9MemorySegment *seg = vmThread->javaVM->classMemorySegments->nextSegment;
	while (seg) {
		if (!(*name1Found) 
                    && (seg->heapBase <= name1) 
                    && (seg->heapTop >= name1)
                  ) {
			*name1Found = TRUE;
		}
		/* same for name2 */
                 /* break if both names are found in the segment */
		seg = seg->nextSegment;
	}
}

[hangshao0]

I just noticed this trace point is level 2, so searching the classname is the class segment will have performance impact. There is a better way to fix this. Looking at the caller of j9bcv_checkClassLoadingConstraintsForSignature(), if the sig1 and sig2 are from the J9ROM** macro, then they are in the class segment and don't need to be copied.

The only case that needs to be copied is lookupSig here:

openj9/runtime/vm/lookupmethod.c

Lines 239 to 240 in d1adf51

	J9NameAndSignature * nas = (J9NameAndSignature *) nameAndSig;
	lookupSig = nas->signature;

We could change j9bcv_checkClassLoadingConstraintsForSignature() to pass in additional parameters to whether copy the strings.