private void makeBasicBlocks() {
ExceptionHandler[][] handlers;
try {
handlers = method.getHandlers();
} catch (InvalidClassFileException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
handlers = null;
}
boolean[] r = new boolean[getInstructions().length];
boolean[] catchers = new boolean[getInstructions().length];
// we initially start with both the entry and exit block.
int blockCount = 2;
// Compute r so r[i] == true iff instruction i begins a basic block.
// While doing so count the number of blocks.
r[0] = true;
IInstruction[] instructions = getInstructions();
for (int i = 0; i < instructions.length; i++) {
int[] targets = instructions[i].getBranchTargets();
// if there are any targets, then break the basic block here.
// also break the basic block after a return
if (targets.length > 0 || !instructions[i].isFallThrough()) {
if (i + 1 < instructions.length && !r[i + 1]) {
r[i + 1] = true;
blockCount++;
}
}
for (int j = 0; j < targets.length; j++) {
if (!r[targets[j]]) {
r[targets[j]] = true;
blockCount++;
}
}
if (instructions[i].isPEI()) {
ExceptionHandler[] hs = handlers[i];
// break the basic block here.
if (i + 1 < instructions.length && !r[i + 1]) {
r[i + 1] = true;
blockCount++;
}
if (hs != null && hs.length > 0) {
for (int j = 0; j < hs.length; j++) {
exceptionHandlers.add(hs[j]);
if (!r[hs[j].getHandler()]) {
// we have not discovered the catch block yet.
// form a new basic block
r[hs[j].getHandler()] = true;
blockCount++;
}
catchers[hs[j].getHandler()] = true;
}
}
}
}
BasicBlock entry = new BasicBlock(-1);
addNode(entry);
int j = 1;
for (int i = 0; i < r.length; i++) {
if (r[i]) {
BasicBlock b = new BasicBlock(i);
addNode(b);
if (catchers[i]) {
setCatchBlock(j);
}
j++;
}
}
BasicBlock exit = new BasicBlock(-1);
addNode(exit);
}
