factor AbstractDetectorForParameterArray2 out of ManualMessageDetector

so that in the next commit the upcoming ManualGetStackTraceDetector for
a SLF4J_GET_STACK_TRACE (issue KengoTODA#70) does not have to copy/paste 3/4 of
the ManualMessageDetector

bug-pattern/src/main/java/jp/skypencil/findbugs/slf4j/ManualMessageDetector.java

@@ -1,77 +1,44 @@
 package jp.skypencil.findbugs.slf4j;
 
-import javax.annotation.Nullable;
-
-import jp.skypencil.findbugs.slf4j.parameter.AbstractDetectorForParameterArray;
+import jp.skypencil.findbugs.slf4j.parameter.AbstractDetectorForParameterArray2;
 import jp.skypencil.findbugs.slf4j.parameter.ArrayData;
-import jp.skypencil.findbugs.slf4j.parameter.ArrayDataHandler.Strategy;
-
 import com.google.common.base.Objects;
 
-import edu.umd.cs.findbugs.BugInstance;
 import edu.umd.cs.findbugs.BugReporter;
 import edu.umd.cs.findbugs.OpcodeStack.CustomUserValue;
 import edu.umd.cs.findbugs.OpcodeStack.Item;
 
 @CustomUserValue
-public final class ManualMessageDetector extends AbstractDetectorForParameterArray {
+public final class ManualMessageDetector extends AbstractDetectorForParameterArray2 {
+
  @Item.SpecialKind
  private final int isMessage = Item.defineNewSpecialKind("message generated by throwable object");
 
  public ManualMessageDetector(BugReporter bugReporter) {
- super(bugReporter);
+ super(bugReporter, "SLF4J_MANUALLY_PROVIDED_MESSAGE");
  }
 
  @Override
- protected Strategy createArrayCheckStrategy() {
- return new Strategy() {
- @Override
- public void store(Item storedItem, ArrayData arrayData, int index) {
- if (arrayData == null) {
- return;
- }
-
- if (storedItem.getSpecialKind() == isMessage) {
- arrayData.mark(true);
- }
-
- // Let developer logs exception message, only when argument does not have throwable instance
- // https://github.com/KengoTODA/findbugs-slf4j/issues/31
- if (index == arrayData.getSize() - 1
- && !getThrowableHandler().checkThrowable(storedItem)) {
- arrayData.mark(false);
- }
- }
- };
+ protected int getIsOfInterestKind() {
+ return isMessage;
  }
 
  @Override
- public void afterOpcode(int seen) {
- boolean isInvokingGetMessage = isInvokingGetMessage(seen);
- super.afterOpcode(seen);
-
- if (isInvokingGetMessage && !stack.isTop()) {
- stack.getStackItem(0).setSpecialKind(isMessage);
- }
+ protected boolean isReallyOfInterest(Item storedItem, ArrayData arrayData, int index) {
+ // Let developer logs exception message, only when argument does not have throwable instance
+ // https://github.com/KengoTODA/findbugs-slf4j/issues/31
+ return !(index == arrayData.getSize() - 1
+ && !getThrowableHandler().checkThrowable(storedItem));
  }
 
- private boolean isInvokingGetMessage(int seen) {
+
+ @Override
+ protected boolean isWhatWeWantToDetect(int seen) {
  return seen == INVOKEVIRTUAL
  && !stack.isTop()
  && getThrowableHandler().checkThrowable(getStack().getStackItem(0))
  && (Objects.equal("getMessage", getNameConstantOperand()) ||
  Objects.equal("getLocalizedMessage", getNameConstantOperand()));
  }
 
- @Override
- protected void onLog(@Nullable String format, @Nullable ArrayData arrayData) {
- if (arrayData == null || !arrayData.isMarked()) {
- return;
- }
- BugInstance bugInstance = new BugInstance(this,
- "SLF4J_MANUALLY_PROVIDED_MESSAGE", NORMAL_PRIORITY)
- .addSourceLine(this).addClassAndMethod(this)
- .addCalledMethod(this);
- getBugReporter().reportBug(bugInstance);
- }
 }

bug-pattern/src/main/java/jp/skypencil/findbugs/slf4j/parameter/AbstractDetectorForParameterArray2.java

@@ -0,0 +1,65 @@
+package jp.skypencil.findbugs.slf4j.parameter;
+
+import edu.umd.cs.findbugs.BugInstance;
+import edu.umd.cs.findbugs.BugReporter;
+import edu.umd.cs.findbugs.OpcodeStack.Item;
+import javax.annotation.Nullable;
+import jp.skypencil.findbugs.slf4j.parameter.ArrayDataHandler.Strategy;
+
+public abstract class AbstractDetectorForParameterArray2 extends AbstractDetectorForParameterArray {
+
+ private final String bugPatternName;
+
+ public AbstractDetectorForParameterArray2(BugReporter bugReporter, String bugPatternName) {
+ super(bugReporter);
+ this.bugPatternName = bugPatternName;
+ }
+
+ @Override
+ protected final Strategy createArrayCheckStrategy() {
+ return (storedItem, arrayData, index) -> {
+ if (arrayData == null) {
+ return;
+ }
+
+ if (storedItem.getSpecialKind() == getIsOfInterestKind()) {
+ arrayData.mark(true);
+ }
+
+ if (!isReallyOfInterest(storedItem, arrayData, index)) {
+ arrayData.mark(false);
+ }
+ };
+ }
+
+ protected boolean isReallyOfInterest(Item storedItem, ArrayData arrayData, int index) {
+ return true;
+ }
+
+ @Override
+ public final void afterOpcode(int seen) {
+ boolean isInvokingGetMessage = isWhatWeWantToDetect(seen);
+ super.afterOpcode(seen);
+
+ if (isInvokingGetMessage && !stack.isTop()) {
+ stack.getStackItem(0).setSpecialKind(getIsOfInterestKind());
+ }
+ }
+
+ @Override
+ protected final void onLog(@Nullable String format, @Nullable ArrayData arrayData) {
+ if (arrayData == null || !arrayData.isMarked()) {
+ return;
+ }
+ BugInstance bugInstance = new BugInstance(this,
+ bugPatternName, NORMAL_PRIORITY)
+ .addSourceLine(this).addClassAndMethod(this)
+ .addCalledMethod(this);
+ getBugReporter().reportBug(bugInstance);
+ }
+
+ abstract protected boolean isWhatWeWantToDetect(int seen);
+
+ abstract protected int getIsOfInterestKind();
+
+}