8191981: javac crash when detecting lambda candidates

Ensuring proper positions on the testing AST nodes created by Analyzer.

Reviewed-by: mcimadamore

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Analyzer.java

@@ -63,6 +63,7 @@ import com.sun.tools.javac.util.List;
 import com.sun.tools.javac.util.ListBuffer;
 import com.sun.tools.javac.util.Log;
 import com.sun.tools.javac.util.Options;
+import com.sun.tools.javac.util.Position;
 
 import java.util.EnumSet;
 import java.util.HashMap;
@@ -305,7 +306,7 @@ public class Analyzer {
             JCMethodDecl md = (JCMethodDecl)decls(oldTree.def).head;
             List<JCVariableDecl> params = md.params;
             JCBlock body = md.body;
-            JCLambda newTree = make.Lambda(params, body);
+            JCLambda newTree = make.at(oldTree).Lambda(params, body);
             return List.of(newTree);
         }
 
@@ -418,7 +419,7 @@ public class Analyzer {
         List<JCEnhancedForLoop> rewrite(JCEnhancedForLoop oldTree) {
             JCEnhancedForLoop newTree = copier.copy(oldTree);
             newTree.var = rewriteVarType(oldTree.var);
-            newTree.body = make.Block(0, List.nil());
+            newTree.body = make.at(oldTree.body).Block(0, List.nil());
             return List.of(newTree);
         }
         @Override
@@ -551,7 +552,8 @@ public class Analyzer {
             JCStatement treeToAnalyze = (JCStatement)rewriting.originalTree;
             if (rewriting.env.info.scope.owner.kind == Kind.TYP) {
                 //add a block to hoist potential dangling variable declarations
-                treeToAnalyze = make.Block(Flags.SYNTHETIC, List.of((JCStatement)rewriting.originalTree));
+                treeToAnalyze = make.at(Position.NOPOS)
+                                    .Block(Flags.SYNTHETIC, List.of((JCStatement)rewriting.originalTree));
             }
 
             //TODO: to further refine the analysis, try all rewriting combinations

test/langtools/tools/javac/analyzer/LambdaWithMethod.java

@@ -0,0 +1,17 @@
+/**
+ * @test /nodynamiccopyright/
+ * @bug 8191981
+ * @compile/fail/ref=LambdaWithMethod.out -Werror -XDrawDiagnostics -XDfind=lambda LambdaWithMethod.java
+ */
+
+public class LambdaWithMethod {
+    public static void run(Runnable r) {
+        run(new Runnable() {
+            public void run() {
+                put(get());
+            }
+        });
+    }
+    private static String get() { return null; }
+    private static void put(String i) {}
+}

test/langtools/tools/javac/analyzer/LambdaWithMethod.out

@@ -0,0 +1,4 @@
+LambdaWithMethod.java:9:28: compiler.warn.potential.lambda.found
+- compiler.err.warnings.and.werror
+1 error
+1 warning