// Rewrites a method given the index_map information
void Rewriter::scan_method(methodOop method) {
int nof_jsrs = 0;
bool has_monitor_bytecodes = false;
{
// We cannot tolerate a GC in this block, because we've
// cached the bytecodes in 'code_base'. If the methodOop
// moves, the bytecodes will also move.
No_Safepoint_Verifier nsv;
Bytecodes::Code c;
// Bytecodes and their length
const address code_base = method->code_base();
const int code_length = method->code_size();
int bc_length;
for (int bci = 0; bci < code_length; bci += bc_length) {
address bcp = code_base + bci;
int prefix_length = 0;
c = (Bytecodes::Code)(*bcp);
// Since we have the code, see if we can get the length
// directly. Some more complicated bytecodes will report
// a length of zero, meaning we need to make another method
// call to calculate the length.
bc_length = Bytecodes::length_for(c);
if (bc_length == 0) {
bc_length = Bytecodes::length_at(bcp);
// length_at will put us at the bytecode after the one modified
// by 'wide'. We don't currently examine any of the bytecodes
// modified by wide, but in case we do in the future...
if (c == Bytecodes::_wide) {
prefix_length = 1;
c = (Bytecodes::Code)bcp[1];
}
}
assert(bc_length != 0, "impossible bytecode length");
switch (c) {
case Bytecodes::_lookupswitch : {
#ifndef CC_INTERP
Bytecode_lookupswitch* bc = Bytecode_lookupswitch_at(bcp);
bc->set_code(
bc->number_of_pairs() < BinarySwitchThreshold
? Bytecodes::_fast_linearswitch
: Bytecodes::_fast_binaryswitch
);
#endif
break;
}
case Bytecodes::_getstatic : // fall through
case Bytecodes::_putstatic : // fall through
case Bytecodes::_getfield : // fall through
case Bytecodes::_putfield : // fall through
case Bytecodes::_invokevirtual : // fall through
case Bytecodes::_invokespecial : // fall through
case Bytecodes::_invokestatic :
case Bytecodes::_invokeinterface:
rewrite_member_reference(bcp, prefix_length+1);
break;
case Bytecodes::_invokedynamic:
rewrite_invokedynamic(bcp, prefix_length+1, int(sizeof"@@@@DELETE ME"));
break;
case Bytecodes::_jsr : // fall through
case Bytecodes::_jsr_w : nof_jsrs++; break;
case Bytecodes::_monitorenter : // fall through
case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break;
}
}
}
// Update access flags
if (has_monitor_bytecodes) {
method->set_has_monitor_bytecodes();
}
// The present of a jsr bytecode implies that the method might potentially
// have to be rewritten, so we run the oopMapGenerator on the method
if (nof_jsrs > 0) {
method->set_has_jsrs();
// Second pass will revisit this method.
assert(method->has_jsrs(), "");
}
}
