src/share/classes/com/sun/tools/javac/comp/Flow.java
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@@ -263,10 +263,14 @@
/** The list of exceptions that are either caught or declared to be
* thrown.
*/
List<Type> caught;
+ /** The list of unreferenced automatic resources.
+ */
+ List<Symbol> unrefdResources;
+
/** Set when processing a loop body the second time for DU analysis. */
boolean loopPassTwo = false;
/*-------------------- Environments ----------------------*/
@@ -975,20 +979,56 @@
Bits uninitsTryPrev = uninitsTry;
ListBuffer<PendingExit> prevPendingExits = pendingExits;
pendingExits = new ListBuffer<PendingExit>();
Bits initsTry = inits.dup();
uninitsTry = uninits.dup();
+ unrefdResources = List.nil();
+ for (JCTree resource : tree.resources) {
+ if (resource instanceof JCVariableDecl) {
+ visitVarDef((JCVariableDecl) resource);
+ } else if (resource instanceof JCExpression) {
+ scanExpr((JCExpression) resource);
+ } else {
+ throw new AssertionError(tree); // parser error
+ }
+ }
+ for (JCTree resource : tree.resources) {
+ MethodSymbol topCloseMethod = (MethodSymbol)syms.autoCloseableType.tsym.members().lookup(names.close).sym;
+ List<Type> closeableSupertypes = resource.type.isCompound() ?
+ types.interfaces(resource.type).prepend(types.supertype(resource.type)) :
+ List.of(resource.type);
+ for (Type sup : closeableSupertypes) {
+ if (types.asSuper(sup, syms.autoCloseableType.tsym) != null) {
+ MethodSymbol closeMethod = types.implementation(topCloseMethod, sup.tsym, types, true);
+ for (Type t : closeMethod.getThrownTypes()) {
+ markThrown(tree.body, t);
+ }
+ }
+ }
+ }
scanStat(tree.body);
List<Type> thrownInTry = thrown;
thrown = thrownPrev;
caught = caughtPrev;
boolean aliveEnd = alive;
uninitsTry.andSet(uninits);
Bits initsEnd = inits;
Bits uninitsEnd = uninits;
int nextadrCatch = nextadr;
+ if (unrefdResources.nonEmpty()) {
+ for (List<JCTree> l = tree.resources; l.nonEmpty(); l = l.tail) {
+ if (l.head instanceof JCVariableDecl) {
+ JCVariableDecl v = (JCVariableDecl) l.head;
+ if (unrefdResources.contains(v.sym)) {
+ log.warning(v.pos(),
+ "automatic.resource.not.referenced", v.sym);
+ }
+ }
+ }
+ }
+
List<Type> caughtInTry = List.nil();
for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
alive = true;
JCVariableDecl param = l.head.param;
List<JCExpression> subClauses = TreeInfo.isMultiCatch(l.head) ?
@@ -1291,12 +1331,24 @@
// annotations don't get scanned
tree.underlyingType.accept(this);
}
public void visitIdent(JCIdent tree) {
- if (tree.sym.kind == VAR)
+ if (tree.sym.kind == VAR) {
checkInit(tree.pos(), (VarSymbol)tree.sym);
+ referenced(tree.sym);
+ }
+ }
+
+ void referenced(Symbol sym) {
+ if (unrefdResources != null && unrefdResources.contains(sym)) {
+ ListBuffer<Symbol> lb = new ListBuffer<Symbol>();
+ for (List<Symbol> l = unrefdResources; l.nonEmpty(); l = l.tail)
+ if (l.head != sym)
+ lb.add(l.head);
+ unrefdResources = lb.toList();
+ }
}
public void visitTypeCast(JCTypeCast tree) {
super.visitTypeCast(tree);
if (!tree.type.isErroneous()