Move switch simplifying to main loop

Author: jaskarth

src/org/jetbrains/java/decompiler/main/rels/MethodProcessor.java

@@ -375,7 +375,14 @@ public static RootStatement codeToJava(StructClass cl, StructMethod mt, MethodDe
         decompileRecord.add("CondenseDo", root);
         continue;
       }
-  
+
+      if (root.hasSwitch() && SwitchHelper.simplifySwitches(root, mt, root)) {
+        SequenceHelper.condenseSequences(root); // remove empty blocks
+        decompileRecord.add("SimplifySwitches", root);
+
+        continue;
+      }
+
       // Apply main loop plugin passes
       if (pluginContext.runPasses(JavaPassLocation.MAIN_LOOP, pctx)) {
         root = pctx.getRoot();
@@ -401,26 +408,6 @@ public static RootStatement codeToJava(StructClass cl, StructMethod mt, MethodDe
     decompileRecord.resetMainLoop();
     decompileRecord.add("MainLoopEnd", root);
 
-    // this has to be done after all inlining is done so the case values do not get reverted
-    if (root.hasSwitch() && SwitchHelper.simplifySwitches(root, mt, root)) {
-      SequenceHelper.condenseSequences(root); // remove empty blocks
-      decompileRecord.add("SimplifySwitches", root);
-
-      // If we have simplified switches, try to make switch expressions
-      if (SwitchExpressionHelper.hasSwitchExpressions(root)) {
-        if (SwitchExpressionHelper.processSwitchExpressions(root)) {
-          decompileRecord.add("ProcessSwitchExpr_SS", root);
-
-          // Simplify stack vars to integrate and inline switch expressions
-          StackVarsProcessor.simplifyStackVars(root, mt, cl);
-          decompileRecord.add("SimplifyStackVars_SS", root);
-
-          varProc.setVarVersions(root);
-          decompileRecord.add("SetVarVersions_SS", root);
-        }
-      }
-    }
-
     // Makes constant returns the same type as the method descriptor
     if (ExitHelper.adjustReturnType(root, md)) {
       decompileRecord.add("AdjustReturnType", root);

src/org/jetbrains/java/decompiler/modules/decompiler/SwitchHelper.java

@@ -685,8 +685,9 @@ private static boolean simplifySwitchOnEnumJ21(SwitchStatement switchSt, RootSta
             if (list.size() == 1 && list.get(0) == null) { // default by itself
               Statement st = switchSt.getCaseStatements().get(i);
               if (IfPatternMatchProcessor.isStatementMatchThrow(st)) {
-                // Replace it with an empty block
+                // Replace it with an empty block and remove it
                 st.replaceWithEmpty();
+                switchSt.removeCase(i);
               }
             }
           }

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

@@ -3,6 +3,7 @@
  */
 package org.jetbrains.java.decompiler.modules.decompiler.exps;
 
+import org.jetbrains.java.decompiler.modules.decompiler.ValidationHelper;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.CheckTypesResult;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;
@@ -46,10 +47,6 @@ public VarType getExprType() {
   public CheckTypesResult checkExprTypeBounds() {
     CheckTypesResult result = new CheckTypesResult();
 
-    // TODO: this surely can't be right with switch on enum and string?
-    result.addExprLowerBound(value, VarType.VARTYPE_BYTECHAR);
-    result.addExprUpperBound(value, VarType.VARTYPE_INT);
-
     VarType valType = value.getExprType();
     for (List<Exprent> lst : caseValues) {
       for (Exprent expr : lst) {
@@ -60,7 +57,10 @@ public CheckTypesResult checkExprTypeBounds() {
             : expr.getExprType();
           if (!caseType.equals(valType)) {
             if (valType == null) {
-              throw new IllegalStateException("Invalid switch case set: " + caseValues + " for selector of type " + value.getExprType());
+              ValidationHelper.validateTrue(false, "Couldn't generate a valid merged switch set!");
+              // TODO: should this add a bound of unknown to value?
+              return result;
+//              throw new IllegalStateException("Invalid switch case set: " + caseValues + " for selector of type " + value.getExprType());
             }
             // allow coercion of primitive -> boxes [see TestSwitchPatternMatching18]
             // e.g. `switch(o) { case 40 -> ...; case Integer i -> ...; }`

testData/results/TestEclipseSwitchString.dec

@@ -7,10 +7,10 @@ public class TestEclipseSwitchString {
             return 1;// 10
          case "2":
             return 2;// 12
+         default:
+            System.out.println("Test");// 7
+            return 0;// 15
       }
-
-      System.out.println("Test");// 7
-      return 0;// 15
    }
 
    public int test1(String var1) {
@@ -20,10 +20,10 @@ public class TestEclipseSwitchString {
          case "2":
          case "3":
             return 2;// 27
+         default:
+            System.out.println("Test");// 21
+            return 0;// 30
       }
-
-      System.out.println("Test");// 21
-      return 0;// 30
    }
 
    public int test2(String var1) {
@@ -67,10 +67,10 @@ public class TestEclipseSwitchString {
          case "BB":
          case "Aa":
             return 2;// 68
+         default:
+            System.out.println("Test");// 64
+            return 0;// 70
       }
-
-      System.out.println("Test");// 64
-      return 0;// 70
    }
 
    public int testHashcodeCollision2(String var1) {
@@ -128,20 +128,20 @@ class 'pkg/TestEclipseSwitchString' {
       22      5
       2d      7
       2e      7
-      35      11
-      36      11
-      37      11
-      38      11
-      39      11
-      3a      11
-      3b      11
-      3c      11
+      35      10
+      36      10
+      37      10
+      38      10
+      39      10
+      3a      10
+      3b      10
+      3c      10
       40      6
       41      6
       42      8
       43      8
-      44      12
-      45      12
+      44      11
+      45      11
    }
 
    method 'test1 (Ljava/lang/String;)I' {
@@ -186,20 +186,20 @@ class 'pkg/TestEclipseSwitchString' {
       36      19
       41      20
       42      20
-      49      24
-      4a      24
-      4b      24
-      4c      24
-      4d      24
-      4e      24
-      4f      24
-      50      24
+      49      23
+      4a      23
+      4b      23
+      4c      23
+      4d      23
+      4e      23
+      4f      23
+      50      23
       54      18
       55      18
       56      21
       57      21
-      58      25
-      59      25
+      58      24
+      59      24
    }
 
    method 'test2 (Ljava/lang/String;)I' {
@@ -355,18 +355,18 @@ class 'pkg/TestEclipseSwitchString' {
       1a      66
       22      67
       23      67
-      2a      71
-      2b      71
-      2c      71
-      2d      71
-      2e      71
-      2f      71
-      30      71
-      31      71
+      2a      70
+      2b      70
+      2c      70
+      2d      70
+      2e      70
+      2f      70
+      30      70
+      31      70
       35      68
       36      68
-      37      72
-      38      72
+      37      71
+      38      71
    }
 
    method 'testHashcodeCollision2 (Ljava/lang/String;)I' {
@@ -436,15 +436,15 @@ class 'pkg/TestEclipseSwitchString' {
 
 Lines mapping:
 5 <-> 5
-7 <-> 12
+7 <-> 11
 10 <-> 7
 12 <-> 9
-15 <-> 13
+15 <-> 12
 19 <-> 17
-21 <-> 25
+21 <-> 24
 24 <-> 19
 27 <-> 22
-30 <-> 26
+30 <-> 25
 34 <-> 30
 36 <-> 49
 39 <-> 34
@@ -456,9 +456,9 @@ Lines mapping:
 56 <-> 58
 58 <-> 61
 62 <-> 66
-64 <-> 72
+64 <-> 71
 68 <-> 69
-70 <-> 73
+70 <-> 72
 74 <-> 77
 76 <-> 93
 79 <-> 86
@@ -470,4 +470,4 @@ Not mapped:
 37
 52
 65
-77
+77