private void atSwitchStmnt(Stmnt st) throws CompileError {
compileExpr(st.head());
ArrayList prevBreakList = breakList;
breakList = new ArrayList();
int opcodePc = bytecode.currentPc();
bytecode.addOpcode(LOOKUPSWITCH);
int npads = 3 - (opcodePc & 3);
while (npads-- > 0) bytecode.add(0);
Stmnt body = (Stmnt) st.tail();
int npairs = 0;
for (ASTList list = body; list != null; list = list.tail())
if (((Stmnt) list.head()).getOperator() == CASE) ++npairs;
// opcodePc2 is the position at which the default jump offset is.
int opcodePc2 = bytecode.currentPc();
bytecode.addGap(4);
bytecode.add32bit(npairs);
bytecode.addGap(npairs * 8);
long[] pairs = new long[npairs];
int ipairs = 0;
int defaultPc = -1;
for (ASTList list = body; list != null; list = list.tail()) {
Stmnt label = (Stmnt) list.head();
int op = label.getOperator();
if (op == DEFAULT) defaultPc = bytecode.currentPc();
else if (op != CASE) fatal();
else {
pairs[ipairs++] =
((long) computeLabel(label.head()) << 32)
+ ((long) (bytecode.currentPc() - opcodePc) & 0xffffffff);
}
hasReturned = false;
((Stmnt) label.tail()).accept(this);
}
Arrays.sort(pairs);
int pc = opcodePc2 + 8;
for (int i = 0; i < npairs; ++i) {
bytecode.write32bit(pc, (int) (pairs[i] >>> 32));
bytecode.write32bit(pc + 4, (int) pairs[i]);
pc += 8;
}
if (defaultPc < 0 || breakList.size() > 0) hasReturned = false;
int endPc = bytecode.currentPc();
if (defaultPc < 0) defaultPc = endPc;
bytecode.write32bit(opcodePc2, defaultPc - opcodePc);
patchGoto(breakList, endPc);
breakList = prevBreakList;
}
private void atWhileStmnt(Stmnt st, boolean notDo) throws CompileError {
ArrayList prevBreakList = breakList;
ArrayList prevContList = continueList;
breakList = new ArrayList();
continueList = new ArrayList();
ASTree expr = st.head();
Stmnt body = (Stmnt) st.tail();
int pc = 0;
if (notDo) {
bytecode.addOpcode(Opcode.GOTO);
pc = bytecode.currentPc();
bytecode.addIndex(0);
}
int pc2 = bytecode.currentPc();
if (body != null) body.accept(this);
int pc3 = bytecode.currentPc();
if (notDo) bytecode.write16bit(pc, pc3 - pc + 1);
boolean alwaysBranch = compileBooleanExpr(true, expr);
if (alwaysBranch) {
bytecode.addOpcode(Opcode.GOTO);
alwaysBranch = breakList.size() == 0;
}
bytecode.addIndex(pc2 - bytecode.currentPc() + 1);
patchGoto(breakList, bytecode.currentPc());
patchGoto(continueList, pc3);
continueList = prevContList;
breakList = prevBreakList;
hasReturned = alwaysBranch;
}
private void atIfStmnt(Stmnt st) throws CompileError {
ASTree expr = st.head();
Stmnt thenp = (Stmnt) st.tail().head();
Stmnt elsep = (Stmnt) st.tail().tail().head();
if (compileBooleanExpr(false, expr)) {
hasReturned = false;
if (elsep != null) elsep.accept(this);
return;
}
int pc = bytecode.currentPc();
int pc2 = 0;
bytecode.addIndex(0); // correct later
hasReturned = false;
if (thenp != null) thenp.accept(this);
boolean thenHasReturned = hasReturned;
hasReturned = false;
if (elsep != null && !thenHasReturned) {
bytecode.addOpcode(Opcode.GOTO);
pc2 = bytecode.currentPc();
bytecode.addIndex(0);
}
bytecode.write16bit(pc, bytecode.currentPc() - pc + 1);
if (elsep != null) {
elsep.accept(this);
if (!thenHasReturned) bytecode.write16bit(pc2, bytecode.currentPc() - pc2 + 1);
hasReturned = thenHasReturned && hasReturned;
}
}
private void atSyncStmnt(Stmnt st) throws CompileError {
int nbreaks = getListSize(breakList);
int ncontinues = getListSize(continueList);
compileExpr(st.head());
if (exprType != CLASS && arrayDim == 0)
throw new CompileError("bad type expr for synchronized block");
Bytecode bc = bytecode;
final int var = bc.getMaxLocals();
bc.incMaxLocals(1);
bc.addOpcode(DUP);
bc.addAstore(var);
bc.addOpcode(MONITORENTER);
ReturnHook rh =
new ReturnHook(this) {
protected boolean doit(Bytecode b, int opcode) {
b.addAload(var);
b.addOpcode(MONITOREXIT);
return false;
}
};
int pc = bc.currentPc();
Stmnt body = (Stmnt) st.tail();
if (body != null) body.accept(this);
int pc2 = bc.currentPc();
int pc3 = 0;
if (!hasReturned) {
rh.doit(bc, 0); // the 2nd arg is ignored.
bc.addOpcode(Opcode.GOTO);
pc3 = bc.currentPc();
bc.addIndex(0);
}
if (pc < pc2) { // if the body is not empty
int pc4 = bc.currentPc();
rh.doit(bc, 0); // the 2nd arg is ignored.
bc.addOpcode(ATHROW);
bc.addExceptionHandler(pc, pc2, pc4, 0);
}
if (!hasReturned) bc.write16bit(pc3, bc.currentPc() - pc3 + 1);
rh.remove(this);
if (getListSize(breakList) != nbreaks || getListSize(continueList) != ncontinues)
throw new CompileError("sorry, cannot break/continue in synchronized block");
}
private void atForStmnt(Stmnt st) throws CompileError {
ArrayList prevBreakList = breakList;
ArrayList prevContList = continueList;
breakList = new ArrayList();
continueList = new ArrayList();
Stmnt init = (Stmnt) st.head();
ASTList p = st.tail();
ASTree expr = p.head();
p = p.tail();
Stmnt update = (Stmnt) p.head();
Stmnt body = (Stmnt) p.tail();
if (init != null) init.accept(this);
int pc = bytecode.currentPc();
int pc2 = 0;
if (expr != null) {
if (compileBooleanExpr(false, expr)) {
// in case of "for (...; false; ...)"
continueList = prevContList;
breakList = prevBreakList;
hasReturned = false;
return;
}
pc2 = bytecode.currentPc();
bytecode.addIndex(0);
}
if (body != null) body.accept(this);
int pc3 = bytecode.currentPc();
if (update != null) update.accept(this);
bytecode.addOpcode(Opcode.GOTO);
bytecode.addIndex(pc - bytecode.currentPc() + 1);
int pc4 = bytecode.currentPc();
if (expr != null) bytecode.write16bit(pc2, pc4 - pc2 + 1);
patchGoto(breakList, pc4);
patchGoto(continueList, pc3);
continueList = prevContList;
breakList = prevBreakList;
hasReturned = false;
}
