8012003: Method diagnostics resolution need to be simplified in some cases

Unfold method resolution diagnostics when they mention errors in poly expressions

Reviewed-by: jjg, vromero

langtools/src/share/classes/com/sun/tools/javac/comp/Attr.java

@@ -2391,7 +2391,8 @@ public class Attr extends JCTree.Visitor {
                     for (JCDiagnostic deferredDiag : lambdaDeferredHandler.getDiagnostics()) {
                         if (deferredDiag.getKind() == JCDiagnostic.Kind.ERROR) {
                             resultInfo.checkContext
-                                    .report(that, diags.fragment("bad.arg.types.in.lambda", TreeInfo.types(that.params)));
+                                    .report(that, diags.fragment("bad.arg.types.in.lambda", TreeInfo.types(that.params),
+                                    deferredDiag)); //hidden diag parameter
                             //we mark the lambda as erroneous - this is crucial in the recovery step
                             //as parameter-dependent type error won't be reported in that stage,
                             //meaning that a lambda will be deemed erroeneous only if there is

langtools/src/share/classes/com/sun/tools/javac/comp/Resolve.java

@@ -37,7 +37,10 @@ import com.sun.tools.javac.comp.DeferredAttr.DeferredType;
 import com.sun.tools.javac.comp.Infer.InferenceContext;
 import com.sun.tools.javac.comp.Infer.FreeTypeListener;
 import com.sun.tools.javac.comp.Resolve.MethodResolutionContext.Candidate;
+import com.sun.tools.javac.comp.Resolve.MethodResolutionDiagHelper.DiagnosticRewriter;
+import com.sun.tools.javac.comp.Resolve.MethodResolutionDiagHelper.Template;
 import com.sun.tools.javac.jvm.*;
+import com.sun.tools.javac.main.Option;
 import com.sun.tools.javac.tree.*;
 import com.sun.tools.javac.tree.JCTree.*;
 import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind;
@@ -94,6 +97,7 @@ public class Resolve {
     public final boolean allowDefaultMethods;
     public final boolean allowStructuralMostSpecific;
     private final boolean debugResolve;
+    private final boolean compactMethodDiags;
     final EnumSet<VerboseResolutionMode> verboseResolutionMode;
 
     Scope polymorphicSignatureScope;
@@ -124,6 +128,8 @@ public class Resolve {
         varargsEnabled = source.allowVarargs();
         Options options = Options.instance(context);
         debugResolve = options.isSet("debugresolve");
+        compactMethodDiags = options.isSet(Option.XDIAGS, "compact") ||
+                options.isUnset(Option.XDIAGS) && options.isUnset("rawDiagnostics");
         verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
         Target target = Target.instance(context);
         allowMethodHandles = target.hasMethodHandles();
@@ -661,6 +667,10 @@ public class Resolve {
             this.basicKey = basicKey;
             this.inferKey = inferKey;
         }
+
+        String regex() {
+            return String.format("([a-z]*\\.)*(%s|%s)", basicKey, inferKey);
+        }
     }
 
     /**
@@ -691,6 +701,7 @@ public class Resolve {
                                     Warner warn) {
             //should we expand formals?
             boolean useVarargs = deferredAttrContext.phase.isVarargsRequired();
+            List<JCExpression> trees = TreeInfo.args(env.tree);
 
             //inference context used during this method check
             InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
@@ -699,17 +710,19 @@ public class Resolve {
 
             if (varargsFormal == null &&
                     argtypes.size() != formals.size()) {
-                reportMC(MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
+                reportMC(env.tree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
             }
 
             while (argtypes.nonEmpty() && formals.head != varargsFormal) {
-                checkArg(false, argtypes.head, formals.head, deferredAttrContext, warn);
+                DiagnosticPosition pos = trees != null ? trees.head : null;
+                checkArg(pos, false, argtypes.head, formals.head, deferredAttrContext, warn);
                 argtypes = argtypes.tail;
                 formals = formals.tail;
+                trees = trees != null ? trees.tail : trees;
             }
 
             if (formals.head != varargsFormal) {
-                reportMC(MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
+                reportMC(env.tree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
             }
 
             if (useVarargs) {
@@ -717,8 +730,10 @@ public class Resolve {
                 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
                 final Type elt = types.elemtype(varargsFormal);
                 while (argtypes.nonEmpty()) {
-                    checkArg(true, argtypes.head, elt, deferredAttrContext, warn);
+                    DiagnosticPosition pos = trees != null ? trees.head : null;
+                    checkArg(pos, true, argtypes.head, elt, deferredAttrContext, warn);
                     argtypes = argtypes.tail;
+                    trees = trees != null ? trees.tail : trees;
                 }
             }
         }
@@ -726,9 +741,9 @@ public class Resolve {
         /**
          * Does the actual argument conforms to the corresponding formal?
          */
-        abstract void checkArg(boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn);
+        abstract void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn);
 
-        protected void reportMC(MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
+        protected void reportMC(DiagnosticPosition pos, MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
             boolean inferDiag = inferenceContext != infer.emptyContext;
             InapplicableMethodException ex = inferDiag ?
                     infer.inferenceException : inapplicableMethodException;
@@ -738,7 +753,8 @@ public class Resolve {
                 args2[0] = inferenceContext.inferenceVars();
                 args = args2;
             }
-            throw ex.setMessage(inferDiag ? diag.inferKey : diag.basicKey, args);
+            String key = inferDiag ? diag.inferKey : diag.basicKey;
+            throw ex.setMessage(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args));
         }
 
         public MethodCheck mostSpecificCheck(List<Type> actuals, boolean strict) {
@@ -752,7 +768,7 @@ public class Resolve {
      */
     MethodCheck arityMethodCheck = new AbstractMethodCheck() {
         @Override
-        void checkArg(boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
+        void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
             //do nothing - actual always compatible to formals
         }
     };
@@ -778,9 +794,9 @@ public class Resolve {
     MethodCheck resolveMethodCheck = new AbstractMethodCheck() {
 
         @Override
-        void checkArg(boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
+        void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
             ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
-            mresult.check(null, actual);
+            mresult.check(pos, actual);
         }
 
         @Override
@@ -809,7 +825,7 @@ public class Resolve {
             } else {
                 if (!isAccessible(env, t)) {
                     Symbol location = env.enclClass.sym;
-                    reportMC(MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
+                    reportMC(env.tree, MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
                 }
             }
         }
@@ -822,7 +838,7 @@ public class Resolve {
 
                 @Override
                 public void report(DiagnosticPosition pos, JCDiagnostic details) {
-                    reportMC(methodDiag, deferredAttrContext.inferenceContext, details);
+                    reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
                 }
             };
             return new MethodResultInfo(to, checkContext);
@@ -3327,6 +3343,18 @@ public class Resolve {
             }
             else {
                 Candidate c = errCandidate();
+                if (compactMethodDiags) {
+                    for (Map.Entry<Template, DiagnosticRewriter> _entry :
+                            MethodResolutionDiagHelper.rewriters.entrySet()) {
+                        if (_entry.getKey().matches(c.details)) {
+                            JCDiagnostic simpleDiag =
+                                    _entry.getValue().rewriteDiagnostic(diags, pos,
+                                        log.currentSource(), dkind, c.details);
+                            simpleDiag.setFlag(DiagnosticFlag.COMPRESSED);
+                            return simpleDiag;
+                        }
+                    }
+                }
                 Symbol ws = c.sym.asMemberOf(site, types);
                 return diags.create(dkind, log.currentSource(), pos,
                           "cant.apply.symbol",
@@ -3375,34 +3403,74 @@ public class Resolve {
                 Name name,
                 List<Type> argtypes,
                 List<Type> typeargtypes) {
-            if (!resolveContext.candidates.isEmpty()) {
+            Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates();
+            Map<Symbol, JCDiagnostic> filteredCandidates = filterCandidates(candidatesMap);
+            if (filteredCandidates.isEmpty()) {
+                filteredCandidates = candidatesMap;
+            }
+            boolean truncatedDiag = candidatesMap.size() != filteredCandidates.size();
+            if (filteredCandidates.size() > 1) {
                 JCDiagnostic err = diags.create(dkind,
+                        null,
+                        truncatedDiag ?
+                            EnumSet.of(DiagnosticFlag.COMPRESSED) :
+                            EnumSet.noneOf(DiagnosticFlag.class),
                         log.currentSource(),
                         pos,
                         "cant.apply.symbols",
                         name == names.init ? KindName.CONSTRUCTOR : absentKind(kind),
                         name == names.init ? site.tsym.name : name,
                         methodArguments(argtypes));
-                return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(site));
+                return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(filteredCandidates, site));
+            } else if (filteredCandidates.size() == 1) {
+                JCDiagnostic d =  new InapplicableSymbolError(resolveContext).getDiagnostic(dkind, pos,
+                    location, site, name, argtypes, typeargtypes);
+                if (truncatedDiag) {
+                    d.setFlag(DiagnosticFlag.COMPRESSED);
+                }
+                return d;
             } else {
                 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
                     location, site, name, argtypes, typeargtypes);
             }
         }
-
         //where
-        List<JCDiagnostic> candidateDetails(Type site) {
-            Map<Symbol, JCDiagnostic> details = new LinkedHashMap<Symbol, JCDiagnostic>();
+            private Map<Symbol, JCDiagnostic> mapCandidates() {
+                Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<Symbol, JCDiagnostic>();
                 for (Candidate c : resolveContext.candidates) {
                     if (c.isApplicable()) continue;
-                JCDiagnostic detailDiag = diags.fragment("inapplicable.method",
-                        Kinds.kindName(c.sym),
-                        c.sym.location(site, types),
-                        c.sym.asMemberOf(site, types),
-                        c.details);
-                details.put(c.sym, detailDiag);
+                    candidates.put(c.sym, c.details);
                 }
-            return List.from(details.values());
+                return candidates;
+            }
+
+            Map<Symbol, JCDiagnostic> filterCandidates(Map<Symbol, JCDiagnostic> candidatesMap) {
+                Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<Symbol, JCDiagnostic>();
+                for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
+                    JCDiagnostic d = _entry.getValue();
+                    if (!compactMethodDiags ||
+                            !new Template(MethodCheckDiag.ARITY_MISMATCH.regex()).matches(d)) {
+                        candidates.put(_entry.getKey(), d);
+                    }
+                }
+                return candidates;
+            }
+
+            private List<JCDiagnostic> candidateDetails(Map<Symbol, JCDiagnostic> candidatesMap, Type site) {
+                List<JCDiagnostic> details = List.nil();
+                for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) {
+                    Symbol sym = _entry.getKey();
+                    JCDiagnostic detailDiag = diags.fragment("inapplicable.method",
+                            Kinds.kindName(sym),
+                            sym.location(site, types),
+                            sym.asMemberOf(site, types),
+                            _entry.getValue());
+                    details = details.prepend(detailDiag);
+                }
+                //typically members are visited in reverse order (see Scope)
+                //so we need to reverse the candidate list so that candidates
+                //conform to source order
+                return details;
             }
     }
 
@@ -3624,6 +3692,105 @@ public class Resolve {
         }
     }
 
+    /**
+     * Helper class for method resolution diagnostic simplification.
+     * Certain resolution diagnostic are rewritten as simpler diagnostic
+     * where the enclosing resolution diagnostic (i.e. 'inapplicable method')
+     * is stripped away, as it doesn't carry additional info. The logic
+     * for matching a given diagnostic is given in terms of a template
+     * hierarchy: a diagnostic template can be specified programmatically,
+     * so that only certain diagnostics are matched. Each templete is then
+     * associated with a rewriter object that carries out the task of rewtiting
+     * the diagnostic to a simpler one.
+     */
+    static class MethodResolutionDiagHelper {
+
+        /**
+         * A diagnostic rewriter transforms a method resolution diagnostic
+         * into a simpler one
+         */
+        interface DiagnosticRewriter {
+            JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
+                    DiagnosticPosition preferedPos, DiagnosticSource preferredSource,
+                    DiagnosticType preferredKind, JCDiagnostic d);
+        }
+
+        /**
+         * A diagnostic template is made up of two ingredients: (i) a regular
+         * expression for matching a diagnostic key and (ii) a list of sub-templates
+         * for matching diagnostic arguments.
+         */
+        static class Template {
+
+            /** regex used to match diag key */
+            String regex;
+
+            /** templates used to match diagnostic args */
+            Template[] subTemplates;
+
+            Template(String key, Template... subTemplates) {
+                this.regex = key;
+                this.subTemplates = subTemplates;
+            }
+
+            /**
+             * Returns true if the regex matches the diagnostic key and if
+             * all diagnostic arguments are matches by corresponding sub-templates.
+             */
+            boolean matches(Object o) {
+                JCDiagnostic d = (JCDiagnostic)o;
+                Object[] args = d.getArgs();
+                if (!d.getCode().matches(regex) ||
+                        subTemplates.length != d.getArgs().length) {
+                    return false;
+                }
+                for (int i = 0; i < args.length ; i++) {
+                    if (!subTemplates[i].matches(args[i])) {
+                        return false;
+                    }
+                }
+                return true;
+            }
+        }
+
+        /** a dummy template that match any diagnostic argument */
+        static final Template skip = new Template("") {
+            @Override
+            boolean matches(Object d) {
+                return true;
+            }
+        };
+
+        /** rewriter map used for method resolution simplification */
+        static final Map<Template, DiagnosticRewriter> rewriters =
+                new LinkedHashMap<Template, DiagnosticRewriter>();
+
+        static {
+            String argMismatchRegex = MethodCheckDiag.ARG_MISMATCH.regex();
+            rewriters.put(new Template(argMismatchRegex, new Template("(.*)(bad.arg.types.in.lambda)", skip, skip)),
+                    new DiagnosticRewriter() {
+                @Override
+                public JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
+                        DiagnosticPosition preferedPos, DiagnosticSource preferredSource,
+                        DiagnosticType preferredKind, JCDiagnostic d) {
+                    return (JCDiagnostic)((JCDiagnostic)d.getArgs()[0]).getArgs()[1];
+                }
+            });
+
+            rewriters.put(new Template(argMismatchRegex, skip),
+                    new DiagnosticRewriter() {
+                @Override
+                public JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags,
+                        DiagnosticPosition preferedPos, DiagnosticSource preferredSource,
+                        DiagnosticType preferredKind, JCDiagnostic d) {
+                    JCDiagnostic cause = (JCDiagnostic)d.getArgs()[0];
+                    return diags.create(preferredKind, preferredSource, d.getDiagnosticPosition(),
+                            "prob.found.req", cause);
+                }
+            });
+        }
+    }
+
     enum MethodResolutionPhase {
         BASIC(false, false),
         BOX(true, false),

langtools/src/share/classes/com/sun/tools/javac/main/JavaCompiler.java

@@ -1614,6 +1614,9 @@ public class JavaCompiler implements ClassReader.SourceCompleter {
                 log.warning("proc.use.proc.or.implicit");
         }
         chk.reportDeferredDiagnostics();
+        if (log.compressedOutput) {
+            log.mandatoryNote(null, "compressed.diags");
+        }
     }
 
     /** Close the compiler, flushing the logs

langtools/src/share/classes/com/sun/tools/javac/main/Option.java

@@ -407,6 +407,8 @@ public enum Option {
         }
     },
 
+    XDIAGS("-Xdiags:", "opt.diags", EXTENDED, BASIC, ONEOF, "compact", "verbose"),
+
     /* This is a back door to the compiler's option table.
      * -XDx=y sets the option x to the value y.
      * -XDx sets the option x to the value x.

langtools/src/share/classes/com/sun/tools/javac/resources/compiler.properties

@@ -227,11 +227,13 @@ compiler.misc.not.an.intf.component=\
 
 # 0: symbol kind, 1: message segment
 compiler.err.invalid.mref=\
-    invalid {0} reference; {1}
+    invalid {0} reference\n\
+    {1}
 
 # 0: symbol kind, 1: message segment
 compiler.misc.invalid.mref=\
-    invalid {0} reference; {1}
+    invalid {0} reference\n\
+    {1}
 
 compiler.misc.static.mref.with.targs=\
     parameterized qualifier on static method reference
@@ -714,7 +716,8 @@ compiler.err.neither.conditional.subtype=\
 
 # 0: message segment
 compiler.misc.incompatible.type.in.conditional=\
-    bad type in conditional expression; {0}
+    bad type in conditional expression\n\
+    {0}
 
 compiler.misc.conditional.target.cant.be.void=\
     target-type for conditional expression cannot be void
@@ -743,7 +746,7 @@ compiler.misc.incompatible.arg.types.in.lambda=\
 compiler.misc.incompatible.arg.types.in.mref=\
     incompatible parameter types in method reference
 
-# 0: list of type
+# 0: list of type, 1: message segment
 compiler.misc.bad.arg.types.in.lambda=\
     cannot type-check lambda expression with inferred parameter types\n\
     inferred types: {0}
@@ -1154,6 +1157,9 @@ compiler.misc.x.print.rounds=\
 ## The following string will appear before all messages keyed as:
 ## "compiler.note".
 
+compiler.note.compressed.diags=\
+    Some messages have been simplified; recompile with -Xdiags:verbose to get full output
+
 compiler.note.potential.lambda.found=\
     This anonymous inner class creation can be turned into a lambda expression.
 
@@ -1742,6 +1748,10 @@ compiler.err.not.within.bounds=\
 compiler.err.prob.found.req=\
     incompatible types: {0}
 
+# 0: message segment
+compiler.misc.prob.found.req=\
+    incompatible types: {0}
+
 # 0: message segment, 1: type, 2: type
 compiler.warn.prob.found.req=\
     {0}\n\

langtools/src/share/classes/com/sun/tools/javac/resources/javac.properties

@@ -168,6 +168,8 @@ javac.opt.prefer=\
     Specify which file to read when both a source file and class file are found for an implicitly compiled class
 javac.opt.AT=\
     Read options and filenames from file
+javac.opt.diags=\
+    Select a diagnostic mode
 
 ## errors
 

langtools/src/share/classes/com/sun/tools/javac/util/JCDiagnostic.java

@@ -349,6 +349,7 @@ public class JCDiagnostic implements Diagnostic<JavaFileObject> {
         SYNTAX,
         RECOVERABLE,
         NON_DEFERRABLE,
+        COMPRESSED
     }
 
     private final DiagnosticType type;

langtools/src/share/classes/com/sun/tools/javac/util/List.java

@@ -154,11 +154,11 @@ public class List<A> extends AbstractCollection<A> implements java.util.List<A>
     }
 
     public static <A> List<A> from(Iterable<? extends A> coll) {
-        List<A> xs = nil();
+        ListBuffer<A> xs = ListBuffer.lb();
         for (A a : coll) {
-            xs = new List<A>(a, xs);
+            xs.append(a);
         }
-        return xs;
+        return xs.toList();
     }
 
     /** Construct a list consisting of a given number of identical elements.

langtools/src/share/classes/com/sun/tools/javac/util/Log.java

@@ -213,6 +213,11 @@ public class Log extends AbstractLog {
      */
     public Set<String> expectDiagKeys;
 
+    /**
+     * Set to true if a compressed diagnostic is reported
+     */
+    public boolean compressedOutput;
+
     /**
      * JavacMessages object used for localization.
      */
@@ -597,6 +602,9 @@ public class Log extends AbstractLog {
                 }
                 break;
             }
+            if (diagnostic.isFlagSet(JCDiagnostic.DiagnosticFlag.COMPRESSED)) {
+                compressedOutput = true;
+            }
         }
     }
 

langtools/test/tools/javac/Diagnostics/compressed/T8012003a.java

@@ -0,0 +1,24 @@
+/**
+ * @test /nodynamiccopyright/
+ * @bug     8012003
+ * @summary Method diagnostics resolution need to be simplified in some cases
+ *          test general overload resolution simplifications
+ * @compile/fail/ref=T8012003a.out -XDrawDiagnostics -Xdiags:compact T8012003a.java
+ */
+
+class T8012003a {
+    void m1(Integer i) { }
+
+    void m2(Integer i) { }
+    void m2(Integer i, Object o) { }
+
+    void m3(Integer i) { }
+    void m3(String s) { }
+
+    void test() {
+        m1("");
+        m1(false ? "" : "");
+        m2("");
+        m3('x');
+    }
+}

langtools/test/tools/javac/Diagnostics/compressed/T8012003a.out

@@ -0,0 +1,6 @@
+T8012003a.java:19:12: compiler.err.prob.found.req: (compiler.misc.inconvertible.types: java.lang.String, java.lang.Integer)
+T8012003a.java:20:20: compiler.err.prob.found.req: (compiler.misc.incompatible.type.in.conditional: (compiler.misc.inconvertible.types: java.lang.String, java.lang.Integer))
+T8012003a.java:21:12: compiler.err.prob.found.req: (compiler.misc.inconvertible.types: java.lang.String, java.lang.Integer)
+T8012003a.java:22:9: compiler.err.cant.apply.symbols: kindname.method, m3, char,{(compiler.misc.inapplicable.method: kindname.method, T8012003a, m3(java.lang.Integer), (compiler.misc.no.conforming.assignment.exists: (compiler.misc.inconvertible.types: char, java.lang.Integer))),(compiler.misc.inapplicable.method: kindname.method, T8012003a, m3(java.lang.String), (compiler.misc.no.conforming.assignment.exists: (compiler.misc.inconvertible.types: char, java.lang.String)))}
+- compiler.note.compressed.diags
+4 errors

langtools/test/tools/javac/Diagnostics/compressed/T8012003b.java

@@ -0,0 +1,37 @@
+/**
+ * @test /nodynamiccopyright/
+ * @bug     8012003
+ * @summary Method diagnostics resolution need to be simplified in some cases
+ *          test lambda-related overload resolution simplifications
+ * @compile/fail/ref=T8012003b.out -XDrawDiagnostics -Xdiags:compact T8012003b.java
+ */
+
+class T8012003b {
+
+    interface Consumer_V<X> {
+        void m(X x);
+    }
+
+    interface Consumer_NV<X> {
+        Integer m(X x);
+    }
+
+    void m1(Runnable r) { }
+    void m1(Runnable r, String s) { }
+
+    void m2(Consumer_V<Integer> ci) { }
+
+    void m3(Consumer_NV<String> ci) { }
+
+    void g(String arg) { }
+    String g2(String arg) { return arg; }
+
+    void test() {
+        m1(this::g);
+        m1(()->1);
+        m1(()->false ? "" : "");
+        m2(this::g);
+        m3(this::g2);
+        m3(this::k);
+    }
+}

langtools/test/tools/javac/Diagnostics/compressed/T8012003b.out

@@ -0,0 +1,8 @@
+T8012003b.java:30:12: compiler.err.prob.found.req: (compiler.misc.invalid.mref: kindname.method, (compiler.misc.cant.apply.symbol: kindname.method, g, java.lang.String, compiler.misc.no.args, kindname.class, T8012003b, (compiler.misc.arg.length.mismatch)))
+T8012003b.java:31:16: compiler.err.prob.found.req: (compiler.misc.incompatible.ret.type.in.lambda: (compiler.misc.inconvertible.types: int, void))
+T8012003b.java:32:22: compiler.err.prob.found.req: (compiler.misc.incompatible.ret.type.in.lambda: (compiler.misc.conditional.target.cant.be.void))
+T8012003b.java:33:12: compiler.err.prob.found.req: (compiler.misc.invalid.mref: kindname.method, (compiler.misc.prob.found.req: (compiler.misc.inconvertible.types: java.lang.Integer, java.lang.String)))
+T8012003b.java:34:12: compiler.err.prob.found.req: (compiler.misc.incompatible.ret.type.in.mref: (compiler.misc.inconvertible.types: java.lang.String, java.lang.Integer))
+T8012003b.java:35:12: compiler.err.invalid.mref: kindname.method, (compiler.misc.cant.resolve.location.args: kindname.method, k, , , (compiler.misc.location: kindname.class, T8012003b, null))
+- compiler.note.compressed.diags
+6 errors

langtools/test/tools/javac/Diagnostics/compressed/T8012003c.java

@@ -0,0 +1,24 @@
+/**
+ * @test /nodynamiccopyright/
+ * @bug     8012003
+ * @summary Method diagnostics resolution need to be simplified in some cases
+ *          test simplification of lambda type-checking error leading to resolution failure
+ * @compile/fail/ref=T8012003c.out -XDrawDiagnostics -Xdiags:compact T8012003c.java
+ */
+
+class T8012003c {
+
+    interface I {
+        void m(P p);
+    }
+
+    void m(I i) { }
+
+    void test() {
+        m(p->p.m());
+    }
+}
+
+class P {
+    private void m() { }
+}

langtools/test/tools/javac/Diagnostics/compressed/T8012003c.out

@@ -0,0 +1,3 @@
+T8012003c.java:18:15: compiler.err.report.access: m(), private, P
+- compiler.note.compressed.diags
+1 error

langtools/test/tools/javac/diags/examples/BadArgTypesInLambda.java

@@ -24,6 +24,9 @@
 // key: compiler.err.cant.apply.symbol
 // key: compiler.misc.no.conforming.assignment.exists
 // key: compiler.misc.bad.arg.types.in.lambda
+// key: compiler.err.prob.found.req
+// key: compiler.misc.inconvertible.types
+// options: -Xdiags:verbose
 
 class BadArgTypesInLambda {
     interface SAM {

langtools/test/tools/javac/diags/examples/CompressedDiags.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+// key: compiler.err.prob.found.req
+// key: compiler.misc.inconvertible.types
+// key: compiler.note.compressed.diags
+// key: compiler.note.note
+// key: compiler.misc.count.error
+// key: compiler.err.error
+// run: backdoor
+
+class CompressedDiags {
+
+    void m(String s) { }
+
+    void test() {
+        m(1);
+    }
+}

langtools/test/tools/javac/diags/examples/KindnameConstructor.java

@@ -28,6 +28,7 @@
 // key: compiler.misc.inconvertible.types
 // key: compiler.misc.count.error
 // key: compiler.err.error
+// options: -Xdiags:verbose
 // run: backdoor
 
 class KindnameConstructor {

langtools/test/tools/javac/diags/examples/ProbFoundReqFragment.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+// key: compiler.err.prob.found.req
+// key: compiler.misc.prob.found.req
+// key: compiler.misc.inconvertible.types
+// key: compiler.misc.invalid.mref
+// key: compiler.misc.kindname.method
+// key: compiler.misc.count.error
+// key: compiler.err.error
+// run: backdoor
+
+class ProbFoundReqFragment {
+
+    interface I {
+        void g(int i);
+    }
+
+    void m(String s) { }
+
+    void test() {
+        I i = this::m;
+    }
+}

langtools/test/tools/javac/lambda/TargetType66.out

@@ -1,4 +1,4 @@
 TargetType66.java:22:9: compiler.err.ref.ambiguous: g, kindname.method, g(TargetType66.SAM1), TargetType66, kindname.method, g(TargetType66.SAM2), TargetType66
-TargetType66.java:23:9: compiler.err.cant.apply.symbols: kindname.method, g, @578,{(compiler.misc.inapplicable.method: kindname.method, TargetType66, g(TargetType66.SAM1), (compiler.misc.no.conforming.assignment.exists: (compiler.misc.bad.arg.types.in.lambda: java.lang.String))),(compiler.misc.inapplicable.method: kindname.method, TargetType66, g(TargetType66.SAM2), (compiler.misc.no.conforming.assignment.exists: (compiler.misc.bad.arg.types.in.lambda: java.lang.Integer)))}
+TargetType66.java:23:9: compiler.err.cant.apply.symbols: kindname.method, g, @578,{(compiler.misc.inapplicable.method: kindname.method, TargetType66, g(TargetType66.SAM1), (compiler.misc.no.conforming.assignment.exists: (compiler.misc.bad.arg.types.in.lambda: java.lang.String, (compiler.err.prob.found.req: (compiler.misc.inconvertible.types: java.lang.String, java.lang.Character))))),(compiler.misc.inapplicable.method: kindname.method, TargetType66, g(TargetType66.SAM2), (compiler.misc.no.conforming.assignment.exists: (compiler.misc.bad.arg.types.in.lambda: java.lang.Integer, (compiler.err.prob.found.req: (compiler.misc.inconvertible.types: java.lang.Integer, java.lang.Character)))))}
 TargetType66.java:24:30: compiler.err.prob.found.req: (compiler.misc.inconvertible.types: java.lang.String, java.lang.Character)
 3 errors