Fix incorrect decompilation of inverted floating point comparisons with NaN (IDEA-196302)

PR #845

GitOrigin-RevId: 611f4af224e68ff8167f2b62f8366a022adb2054

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

@@ -1,4 +1,4 @@
-// Copyright 2000-2017 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.java.decompiler.modules.decompiler;
 
 import org.jetbrains.java.decompiler.code.CodeConstants;
@@ -170,6 +170,17 @@ public class SecondaryFunctionsHelper {
               }
 
               if (desttype >= 0) {
+                if (functype != FunctionExprent.FUNCTION_LCMP) {
+                  boolean oneForNan = functype == FunctionExprent.FUNCTION_DCMPL || functype == FunctionExprent.FUNCTION_FCMPL;
+                  boolean trueForOne = desttype == FunctionExprent.FUNCTION_LT || desttype == FunctionExprent.FUNCTION_LE;
+                  boolean trueForNan = oneForNan == trueForOne;
+                  if (trueForNan) {
+                    List<Exprent> operands = new ArrayList<>();
+                    operands.add(new FunctionExprent(funcsnot[desttype - FunctionExprent.FUNCTION_EQ],
+                      funcexpr.getLstOperands(), funcexpr.bytecode));
+                    return new FunctionExprent(FunctionExprent.FUNCTION_BOOL_NOT, operands, funcexpr.bytecode);
+                  }
+                }
                 return new FunctionExprent(desttype, funcexpr.getLstOperands(), funcexpr.bytecode);
               }
             }
@@ -378,6 +389,7 @@ public class SecondaryFunctionsHelper {
           FunctionExprent fparam = (FunctionExprent)param;
 
           int ftype = fparam.getFuncType();
+          boolean canSimplify = false;
           switch (ftype) {
             case FunctionExprent.FUNCTION_BOOL_NOT:
               Exprent newexpr = fparam.getLstOperands().get(0);
@@ -394,16 +406,28 @@ public class SecondaryFunctionsHelper {
               }
             case FunctionExprent.FUNCTION_EQ:
             case FunctionExprent.FUNCTION_NE:
+              canSimplify = true;
             case FunctionExprent.FUNCTION_LT:
             case FunctionExprent.FUNCTION_GE:
             case FunctionExprent.FUNCTION_GT:
             case FunctionExprent.FUNCTION_LE:
+              if (!canSimplify) {
+                operands = fparam.getLstOperands();
+                VarType left = operands.get(0).getExprType();
+                VarType right = operands.get(1).getExprType();
+                VarType commonSupertype = VarType.getCommonSupertype(left, right);
+                if (commonSupertype != null) {
+                  canSimplify = commonSupertype.type != CodeConstants.TYPE_FLOAT && commonSupertype.type != CodeConstants.TYPE_DOUBLE;
+                }
+              }
+              if (canSimplify) {
                 fparam.setFuncType(funcsnot[ftype - FunctionExprent.FUNCTION_EQ]);
                 return fparam;
               }
           }
         }
       }
+    }
 
     return null;
   }

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

@@ -1,4 +1,4 @@
-// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.java.decompiler;
 
 import org.jetbrains.java.decompiler.main.decompiler.ConsoleDecompiler;
@@ -110,6 +110,7 @@ public class SingleClassesTest {
   @Test public void testMissingConstructorCallGood() { doTest("pkg/TestMissingConstructorCallGood"); }
   @Test public void testMissingConstructorCallBad() { doTest("pkg/TestMissingConstructorCallBad"); }
   @Test public void testEmptyBlocks() { doTest("pkg/TestEmptyBlocks"); }
+  @Test public void testInvertedFloatComparison() { doTest("pkg/TestInvertedFloatComparison"); }
   @Test public void testPrivateEmptyConstructor() { doTest("pkg/TestPrivateEmptyConstructor"); }
   @Test public void testSynchronizedUnprotected() { doTest("pkg/TestSynchronizedUnprotected"); }
   @Test public void testInterfaceSuper() { doTest("pkg/TestInterfaceSuper"); }

testData/results/TestInvertedFloatComparison.dec

@@ -0,0 +1,167 @@
+package pkg;
+
+public class TestInvertedFloatComparison {
+   public boolean less(double var1, double var3) {
+      return var1 < var3;// 6
+   }
+
+   public boolean less(int var1, int var2) {
+      return var1 < var2;// 10
+   }
+
+   public boolean notLess(double var1, double var3) {
+      return !(var1 < var3);// 14
+   }
+
+   public boolean notLess(int var1, int var2) {
+      return var1 >= var2;// 18
+   }
+
+   public boolean greater(double var1, double var3) {
+      return var1 > var3;// 22
+   }
+
+   public boolean greater(int var1, int var2) {
+      return var1 > var2;// 26
+   }
+
+   public boolean notGreater(double var1, double var3) {
+      return !(var1 > var3);// 30
+   }
+
+   public boolean notGreater(int var1, int var2) {
+      return var1 <= var2;// 34
+   }
+
+   public boolean lessEqual(double var1, double var3) {
+      return var1 <= var3;// 38
+   }
+
+   public boolean lessEqual(int var1, int var2) {
+      return var1 <= var2;// 42
+   }
+
+   public boolean notLessEqual(double var1, double var3) {
+      return !(var1 <= var3);// 46
+   }
+
+   public boolean notLessEqual(int var1, int var2) {
+      return var1 > var2;// 50
+   }
+
+   public boolean greaterEqual(double var1, double var3) {
+      return var1 >= var3;// 54
+   }
+
+   public boolean greaterEqual(int var1, int var2) {
+      return var1 >= var2;// 58
+   }
+
+   public boolean notGreaterEqual(double var1, double var3) {
+      return !(var1 >= var3);// 62
+   }
+
+   public boolean notGreaterEqual(int var1, int var2) {
+      return var1 < var2;// 66
+   }
+}
+
+class 'pkg/TestInvertedFloatComparison' {
+   method 'less (DD)Z' {
+      2      4
+      b      4
+   }
+
+   method 'less (II)Z' {
+      2      8
+      a      8
+   }
+
+   method 'notLess (DD)Z' {
+      2      12
+      b      12
+   }
+
+   method 'notLess (II)Z' {
+      2      16
+      a      16
+   }
+
+   method 'greater (DD)Z' {
+      2      20
+      b      20
+   }
+
+   method 'greater (II)Z' {
+      2      24
+      a      24
+   }
+
+   method 'notGreater (DD)Z' {
+      2      28
+      b      28
+   }
+
+   method 'notGreater (II)Z' {
+      2      32
+      a      32
+   }
+
+   method 'lessEqual (DD)Z' {
+      2      36
+      b      36
+   }
+
+   method 'lessEqual (II)Z' {
+      2      40
+      a      40
+   }
+
+   method 'notLessEqual (DD)Z' {
+      2      44
+      b      44
+   }
+
+   method 'notLessEqual (II)Z' {
+      2      48
+      a      48
+   }
+
+   method 'greaterEqual (DD)Z' {
+      2      52
+      b      52
+   }
+
+   method 'greaterEqual (II)Z' {
+      2      56
+      a      56
+   }
+
+   method 'notGreaterEqual (DD)Z' {
+      2      60
+      b      60
+   }
+
+   method 'notGreaterEqual (II)Z' {
+      2      64
+      a      64
+   }
+}
+
+Lines mapping:
+6 <-> 5
+10 <-> 9
+14 <-> 13
+18 <-> 17
+22 <-> 21
+26 <-> 25
+30 <-> 29
+34 <-> 33
+38 <-> 37
+42 <-> 41
+46 <-> 45
+50 <-> 49
+54 <-> 53
+58 <-> 57
+62 <-> 61
+66 <-> 65

testData/src/pkg/TestInvertedFloatComparison.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package pkg;
+
+public class TestInvertedFloatComparison {
+
+  public boolean less(double a, double b) {
+    return a < b;
+  }
+
+  public boolean less(int a, int b) {
+    return a < b;
+  }
+
+  public boolean notLess(double a, double b) {
+    return !(a < b);
+  }
+
+  public boolean notLess(int a, int b) {
+    return !(a < b);
+  }
+
+  public boolean greater(double a, double b) {
+    return a > b;
+  }
+
+  public boolean greater(int a, int b) {
+    return a > b;
+  }
+
+  public boolean notGreater(double a, double b) {
+    return !(a > b);
+  }
+
+  public boolean notGreater(int a, int b) {
+    return !(a > b);
+  }
+
+  public boolean lessEqual(double a, double b) {
+    return a <= b;
+  }
+
+  public boolean lessEqual(int a, int b) {
+    return a <= b;
+  }
+
+  public boolean notLessEqual(double a, double b) {
+    return !(a <= b);
+  }
+
+  public boolean notLessEqual(int a, int b) {
+    return !(a <= b);
+  }
+
+  public boolean greaterEqual(double a, double b) {
+    return a >= b;
+  }
+
+  public boolean greaterEqual(int a, int b) {
+    return a >= b;
+  }
+
+  public boolean notGreaterEqual(double a, double b) {
+    return !(a >= b);
+  }
+
+  public boolean notGreaterEqual(int a, int b) {
+    return !(a >= b);
+  }
+}