Merge pull request #846 from Timbals/fix/operand-side-effects

fix cast error for `Operand`s with side effects

shared-test-resources/bugfixes/NestedMethodCall.java

@@ -0,0 +1,9 @@
+public class NestedMethodCall {
+  public void nestedMethodCall() {
+    int i = 0;
+    String s = "abc";
+    decode(s.charAt(++i), s.charAt(i++));
+  }
+
+  void decode(char first, char second) {}
+}

sootup.java.bytecode/src/main/java/sootup/java/bytecode/frontend/Operand.java

@@ -106,11 +106,12 @@ void changeStackLocal(Local newStackLocal) {
       return;
     }
 
-    JAssignStmt assignStmt = methodSource.getStmt(insn);
-    if (assignStmt == null) {
+    Stmt stmt = methodSource.getStmt(insn);
+    if (!(stmt instanceof JAssignStmt)) {
       // emit `$newStackLocal = value`
       methodSource.setStmt(insn, Jimple.newAssignStmt(newStackLocal, value, positionInfo));
     } else {
+      JAssignStmt assignStmt = (JAssignStmt) stmt;
       assert assignStmt.getLeftOp() == oldStackLocal || assignStmt.getLeftOp() == newStackLocal;
       // replace `$oldStackLocal = value` with `$newStackLocal = value`
       methodSource.replaceStmt(assignStmt, assignStmt.withVariable(newStackLocal));

sootup.java.bytecode/src/test/java/sootup/java/bytecode/frontend/AsmMethodSourceTest.java

@@ -1,17 +1,21 @@
 package sootup.java.bytecode.frontend;
 
 import static junit.framework.Assert.assertTrue;
+import static junit.framework.TestCase.assertEquals;
 import static junit.framework.TestCase.fail;
 
 import categories.Java8Test;
 import java.util.Arrays;
+import java.util.Collections;
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
 import sootup.core.model.SootClass;
 import sootup.core.model.SootMethod;
 import sootup.core.signatures.MethodSignature;
 import sootup.java.bytecode.inputlocation.DefaultRTJarAnalysisInputLocation;
+import sootup.java.bytecode.inputlocation.JavaClassPathAnalysisInputLocation;
 import sootup.java.core.JavaIdentifierFactory;
+import sootup.java.core.JavaSootMethod;
 import sootup.java.core.types.JavaClassType;
 import sootup.java.core.views.JavaView;
 
@@ -47,4 +51,30 @@ public void testFix_StackUnderrun_convertPutFieldInsn_init() {
     final SootMethod method = abstractClass.getMethod(mainMethodSignature.getSubSignature()).get();
     method.getBody().getStmts();
   }
+
+  @Test
+  public void testNestedMethodCalls() {
+    JavaClassPathAnalysisInputLocation inputLocation =
+        new JavaClassPathAnalysisInputLocation("../shared-test-resources/bugfixes/");
+    JavaView view = new JavaView(Collections.singletonList(inputLocation));
+
+    JavaSootMethod method =
+        view.getMethod(
+                JavaIdentifierFactory.getInstance()
+                    .parseMethodSignature("<NestedMethodCall: void nestedMethodCall()>"))
+            .get();
+    assertEquals(
+        "this := @this: NestedMethodCall;\n"
+            + "i = 0;\n"
+            + "s = \"abc\";\n"
+            + "i = i + 1;\n"
+            + "$stack5 = virtualinvoke s.<java.lang.String: char charAt(int)>(i);\n"
+            + "$stack3 = i;\n"
+            + "i = i + 1;\n"
+            + "$stack4 = virtualinvoke s.<java.lang.String: char charAt(int)>($stack3);\n"
+            + "virtualinvoke this.<NestedMethodCall: void decode(char,char)>($stack5, $stack4);\n"
+            + "\n"
+            + "return;",
+        method.getBody().getStmtGraph().toString().trim());
+  }
 }