Fix generic mapping stack overflow

Author: jaskarth

src/org/jetbrains/java/decompiler/modules/decompiler/exps/InvocationExprent.java

@@ -307,7 +307,7 @@ else if (!bounds.containsKey(from)) {
                     }
                   }
 
-                  if (ok && isMappingInBounds(from, to, named, bounds)) {
+                  if (ok && isMappingInBounds(from, to, named, bounds, new HashSet<>())) {
                     upperBoundsMap.put(from, to);
                   }
                 }
@@ -1570,12 +1570,12 @@ private boolean processGenericMapping(VarType from, VarType to, Map<VarType, Lis
   }
 
   private void putGenericMapping(VarType from, VarType to, Map<VarType, List<VarType>> named, Map<VarType, List<VarType>> bounds) {
-    if (isMappingInBounds(from, to, named, bounds)) {
+    if (isMappingInBounds(from, to, named, bounds, new HashSet<>())) {
       genericsMap.put(from, to);
     }
   }
 
-  private boolean isMappingInBounds(VarType from, VarType to, Map<VarType, List<VarType>> named, Map<VarType, List<VarType>> bounds) {
+  private boolean isMappingInBounds(VarType from, VarType to, Map<VarType, List<VarType>> named, Map<VarType, List<VarType>> bounds, Set<Pair<VarType, VarType>> recursivelySeen) {
     if (!bounds.containsKey(from)) {
       return false;
     }
@@ -1612,7 +1612,11 @@ private boolean isMappingInBounds(VarType from, VarType to, Map<VarType, List<Va
           }
         }
 
-        return isMappingInBounds(bound, newTo, named, bounds);
+        Pair<VarType, VarType> pair = Pair.of(bound, newTo);
+        if (!recursivelySeen.contains(pair)) {
+          recursivelySeen.add(pair);
+          return isMappingInBounds(bound, newTo, named, bounds, recursivelySeen);
+        }
       }
 
       if (newTo.type.ordinal() < CodeType.OBJECT.ordinal()) {
@@ -1654,9 +1658,15 @@ private boolean isMappingInBounds(VarType from, VarType to, Map<VarType, List<Va
             }
 
             // T extends Comparable<S>, S extends Object
-            if (bounds.containsKey(boundArg) && isMappingInBounds(boundArg, newArg, named, bounds)) {
-              toAdd.put(boundArg, newArg);
-              continue;
+            if (bounds.containsKey(boundArg)) {
+              Pair<VarType, VarType> pair = Pair.of(bound, newTo);
+              if (!recursivelySeen.contains(pair)) {
+                recursivelySeen.add(pair);
+                if (isMappingInBounds(boundArg, newArg, named, bounds, recursivelySeen)) {
+                  toAdd.put(boundArg, newArg);
+                  continue;
+                }
+              }
             }
             return false;
           }

test/org/jetbrains/java/decompiler/SingleClassesTest.java

@@ -716,6 +716,7 @@ private void registerDefault() {
     register(JAVA_8, "TestExtraneousImports");
     register(JAVA_17, "TestSwitchOnEnumFake");
     register(JAVA_16, "TestSwitchExpressionReturnType");
+    register(JAVA_8, "TestGenericMapping");
 
   }
 

testData/results/pkg/TestGenericMapping.dec

@@ -0,0 +1,36 @@
+package pkg;
+
+public class TestGenericMapping {
+   class EntityA<Q extends TestGenericMapping.EntityA<Q, R>, R extends TestGenericMapping.EntityB<Q, R>> {
+      public void doSomething(Q q) {
+      }// 6
+   }
+
+   public class EntityB<S extends TestGenericMapping.EntityA<S, T>, T extends TestGenericMapping.EntityB<S, T>> {
+      public void doSomething(S t) {
+         t.doSomething(t);// 11
+      }// 12
+   }
+}
+
+class 'pkg/TestGenericMapping$EntityA' {
+   method 'doSomething (Lpkg/TestGenericMapping$EntityA;)V' {
+      0      5
+   }
+}
+
+class 'pkg/TestGenericMapping$EntityB' {
+   method 'doSomething (Lpkg/TestGenericMapping$EntityA;)V' {
+      0      10
+      1      10
+      2      10
+      3      10
+      4      10
+      5      11
+   }
+}
+
+Lines mapping:
+6 <-> 6
+11 <-> 11
+12 <-> 12

testData/src/java8/pkg/TestGenericMapping.java

@@ -0,0 +1,14 @@
+package pkg;
+
+public class TestGenericMapping {
+  class EntityA<Q extends EntityA<Q, R>, R extends EntityB<Q, R>> {
+    public void doSomething(final Q q) {
+    }
+  }
+
+  public class EntityB<S extends EntityA<S, T>, T extends EntityB<S, T>> {
+    public void doSomething(final S t) {
+      t.doSomething(t);
+    }
+  }
+}