1.1 --- a/src/share/classes/com/sun/tools/javac/comp/Flow.java Tue Mar 15 14:19:00 2011 -0700
1.2 +++ b/src/share/classes/com/sun/tools/javac/comp/Flow.java Wed Mar 16 11:12:26 2011 +0000
1.3 @@ -190,7 +190,8 @@
1.4 private final Resolve rs;
1.5 private Env<AttrContext> attrEnv;
1.6 private Lint lint;
1.7 - private final boolean allowRethrowAnalysis;
1.8 + private final boolean allowImprovedRethrowAnalysis;
1.9 + private final boolean allowImprovedCatchAnalysis;
1.10
1.11 public static Flow instance(Context context) {
1.12 Flow instance = context.get(flowKey);
1.13 @@ -209,7 +210,8 @@
1.14 lint = Lint.instance(context);
1.15 rs = Resolve.instance(context);
1.16 Source source = Source.instance(context);
1.17 - allowRethrowAnalysis = source.allowMulticatch();
1.18 + allowImprovedRethrowAnalysis = source.allowImprovedRethrowAnalysis();
1.19 + allowImprovedCatchAnalysis = source.allowImprovedCatchAnalysis();
1.20 }
1.21
1.22 /** A flag that indicates whether the last statement could
1.23 @@ -1046,7 +1048,9 @@
1.24 }
1.25 }
1.26 scanStat(tree.body);
1.27 - List<Type> thrownInTry = thrown;
1.28 + List<Type> thrownInTry = allowImprovedCatchAnalysis ?
1.29 + chk.union(thrown, List.of(syms.runtimeExceptionType, syms.errorType)) :
1.30 + thrown;
1.31 thrown = thrownPrev;
1.32 caught = caughtPrev;
1.33 boolean aliveEnd = alive;
1.34 @@ -1081,16 +1085,7 @@
1.35 ctypes = ctypes.append(exc);
1.36 if (types.isSameType(exc, syms.objectType))
1.37 continue;
1.38 - if (chk.subset(exc, caughtInTry)) {
1.39 - log.error(l.head.pos(),
1.40 - "except.already.caught", exc);
1.41 - } else if (!chk.isUnchecked(l.head.pos(), exc) &&
1.42 - exc.tsym != syms.throwableType.tsym &&
1.43 - exc.tsym != syms.exceptionType.tsym &&
1.44 - !chk.intersects(exc, thrownInTry)) {
1.45 - log.error(l.head.pos(),
1.46 - "except.never.thrown.in.try", exc);
1.47 - }
1.48 + checkCaughtType(l.head.pos(), exc, thrownInTry, caughtInTry);
1.49 caughtInTry = chk.incl(exc, caughtInTry);
1.50 }
1.51 }
1.52 @@ -1154,6 +1149,29 @@
1.53 uninitsTry.andSet(uninitsTryPrev).andSet(uninits);
1.54 }
1.55
1.56 + void checkCaughtType(DiagnosticPosition pos, Type exc, List<Type> thrownInTry, List<Type> caughtInTry) {
1.57 + if (chk.subset(exc, caughtInTry)) {
1.58 + log.error(pos, "except.already.caught", exc);
1.59 + } else if (!chk.isUnchecked(pos, exc) &&
1.60 + exc.tsym != syms.throwableType.tsym &&
1.61 + exc.tsym != syms.exceptionType.tsym &&
1.62 + !chk.intersects(exc, thrownInTry)) {
1.63 + log.error(pos, "except.never.thrown.in.try", exc);
1.64 + } else if (allowImprovedCatchAnalysis) {
1.65 + List<Type> catchableThrownTypes = chk.intersect(List.of(exc), thrownInTry);
1.66 + // 'catchableThrownTypes' cannnot possibly be empty - if 'exc' was an
1.67 + // unchecked exception, the result list would not be empty, as the augmented
1.68 + // thrown set includes { RuntimeException, Error }; if 'exc' was a checked
1.69 + // exception, that would have been covered in the branch above
1.70 + if (chk.diff(catchableThrownTypes, caughtInTry).isEmpty()) {
1.71 + String key = catchableThrownTypes.length() == 1 ?
1.72 + "unreachable.catch" :
1.73 + "unreachable.catch.1";
1.74 + log.warning(pos, key, catchableThrownTypes);
1.75 + }
1.76 + }
1.77 + }
1.78 +
1.79 public void visitConditional(JCConditional tree) {
1.80 scanCond(tree.cond);
1.81 Bits initsBeforeElse = initsWhenFalse;
1.82 @@ -1238,7 +1256,7 @@
1.83 sym.kind == VAR &&
1.84 (sym.flags() & (FINAL | EFFECTIVELY_FINAL)) != 0 &&
1.85 preciseRethrowTypes.get(sym) != null &&
1.86 - allowRethrowAnalysis) {
1.87 + allowImprovedRethrowAnalysis) {
1.88 for (Type t : preciseRethrowTypes.get(sym)) {
1.89 markThrown(tree, t);
1.90 }
