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A packaging of the IntelliJ Community Edition lint-checks library.
This is release number 1 of trunk branch 142.
The newest version!
/*
* Copyright (C) 2015 The Android Open Source Project
*
* 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 com.android.tools.lint.checks;
import static com.android.tools.lint.client.api.JavaParser.TYPE_STRING;
import com.android.annotations.NonNull;
import com.android.annotations.Nullable;
import com.android.tools.lint.client.api.JavaParser.ResolvedField;
import com.android.tools.lint.client.api.JavaParser.ResolvedMethod;
import com.android.tools.lint.client.api.JavaParser.ResolvedNode;
import com.android.tools.lint.detector.api.Category;
import com.android.tools.lint.detector.api.Detector;
import com.android.tools.lint.detector.api.Implementation;
import com.android.tools.lint.detector.api.Issue;
import com.android.tools.lint.detector.api.JavaContext;
import com.android.tools.lint.detector.api.Location;
import com.android.tools.lint.detector.api.Scope;
import com.android.tools.lint.detector.api.Severity;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import lombok.ast.AstVisitor;
import lombok.ast.BinaryExpression;
import lombok.ast.BinaryOperator;
import lombok.ast.ClassDeclaration;
import lombok.ast.Expression;
import lombok.ast.If;
import lombok.ast.MethodInvocation;
import lombok.ast.Node;
import lombok.ast.Select;
import lombok.ast.StringLiteral;
import lombok.ast.VariableReference;
/**
* Detector for finding inefficiencies and errors in logging calls.
*/
public class LogDetector extends Detector implements Detector.JavaScanner {
private static final Implementation IMPLEMENTATION = new Implementation(
LogDetector.class, Scope.JAVA_FILE_SCOPE);
/** Log call missing surrounding if */
public static final Issue CONDITIONAL = Issue.create(
"LogConditional", //$NON-NLS-1$
"Unconditional Logging Calls",
"The BuildConfig class (available in Tools 17) provides a constant, \"DEBUG\", " +
"which indicates whether the code is being built in release mode or in debug " +
"mode. In release mode, you typically want to strip out all the logging calls. " +
"Since the compiler will automatically remove all code which is inside a " +
"\"if (false)\" check, surrounding your logging calls with a check for " +
"BuildConfig.DEBUG is a good idea.\n" +
"\n" +
"If you *really* intend for the logging to be present in release mode, you can " +
"suppress this warning with a @SuppressLint annotation for the intentional " +
"logging calls.",
Category.PERFORMANCE,
5,
Severity.WARNING,
IMPLEMENTATION).setEnabledByDefault(false);
/** Mismatched tags between isLogging and log calls within it */
public static final Issue WRONG_TAG = Issue.create(
"LogTagMismatch", //$NON-NLS-1$
"Mismatched Log Tags",
"When guarding a `Log.v(tag, ...)` call with `Log.isLoggable(tag)`, the " +
"tag passed to both calls should be the same. Similarly, the level passed " +
"in to `Log.isLoggable` should typically match the type of `Log` call, e.g. " +
"if checking level `Log.DEBUG`, the corresponding `Log` call should be `Log.d`, " +
"not `Log.i`.",
Category.CORRECTNESS,
5,
Severity.ERROR,
IMPLEMENTATION);
/** Log tag is too long */
public static final Issue LONG_TAG = Issue.create(
"LongLogTag", //$NON-NLS-1$
"Too Long Log Tags",
"Log tags are only allowed to be at most 23 tag characters long.",
Category.CORRECTNESS,
5,
Severity.ERROR,
IMPLEMENTATION);
@SuppressWarnings("SpellCheckingInspection")
private static final String IS_LOGGABLE = "isLoggable"; //$NON-NLS-1$
private static final String LOG_CLS = "android.util.Log"; //$NON-NLS-1$
private static final String PRINTLN = "println"; //$NON-NLS-1$
// ---- Implements Detector.JavaScanner ----
@Override
public List getApplicableMethodNames() {
return Arrays.asList(
"d", //$NON-NLS-1$
"e", //$NON-NLS-1$
"i", //$NON-NLS-1$
"v", //$NON-NLS-1$
"w", //$NON-NLS-1$
PRINTLN,
IS_LOGGABLE);
}
@Override
public void visitMethod(@NonNull JavaContext context, @Nullable AstVisitor visitor, @NonNull MethodInvocation node) {
ResolvedNode resolved = context.resolve(node);
if (!(resolved instanceof ResolvedMethod)) {
return;
}
ResolvedMethod method = (ResolvedMethod) resolved;
if (!method.getContainingClass().matches(LOG_CLS)) {
return;
}
String name = node.astName().astValue();
boolean withinConditional = IS_LOGGABLE.equals(name) ||
checkWithinConditional(context, node.getParent(), node);
// See if it's surrounded by an if statement (and it's one of the non-error, spammy
// log methods (info, verbose, etc))
if (("i".equals(name) || "d".equals(name) || "v".equals(name) || PRINTLN.equals(name))
&& !withinConditional
&& performsWork(context, node)
&& context.isEnabled(CONDITIONAL)) {
String message = String.format("The log call Log.%1$s(...) should be " +
"conditional: surround with `if (Log.isLoggable(...))` or " +
"`if (BuildConfig.DEBUG) { ... }`",
node.astName().toString());
context.report(CONDITIONAL, node, context.getLocation(node), message);
}
// Check tag length
if (context.isEnabled(LONG_TAG)) {
int tagArgumentIndex = PRINTLN.equals(name) ? 1 : 0;
if (method.getArgumentCount() > tagArgumentIndex
&& method.getArgumentType(tagArgumentIndex).matchesSignature(TYPE_STRING)
&& node.astArguments().size() == method.getArgumentCount()) {
Iterator iterator = node.astArguments().iterator();
if (tagArgumentIndex == 1) {
iterator.next();
}
Node argument = iterator.next();
String tag = findLiteralValue(context, argument);
if (tag != null && tag.length() > 23) {
String message = String.format(
"The logging tag can be at most 23 characters, was %1$d (%2$s)",
tag.length(), tag);
context.report(LONG_TAG, node, context.getLocation(node), message);
}
}
}
}
/** Returns true if the given logging call performs "work" to compute the message */
private static boolean performsWork(
@NonNull JavaContext context,
@NonNull MethodInvocation node) {
int messageArgumentIndex = PRINTLN.equals(node.astName().astValue()) ? 2 : 1;
if (node.astArguments().size() >= messageArgumentIndex) {
Iterator iterator = node.astArguments().iterator();
Node argument = null;
for (int i = 0; i <= messageArgumentIndex; i++) {
argument = iterator.next();
}
if (argument == null) {
return false;
}
if (argument instanceof StringLiteral || argument instanceof VariableReference) {
return false;
}
if (argument instanceof BinaryExpression) {
String string = findLiteralValue(context, argument);
//noinspection VariableNotUsedInsideIf
if (string != null) { // does it resolve to a constant?
return false;
}
} else if (argument instanceof Select) {
String string = findLiteralValue(context, argument);
//noinspection VariableNotUsedInsideIf
if (string != null) {
return false;
}
}
// Method invocations etc
return true;
}
return false;
}
@Nullable
private static String findLiteralValue(@NonNull JavaContext context, @NonNull Node argument) {
if (argument instanceof StringLiteral) {
return ((StringLiteral)argument).astValue();
} else if (argument instanceof BinaryExpression) {
BinaryExpression expression = (BinaryExpression) argument;
if (expression.astOperator() == BinaryOperator.PLUS) {
String left = findLiteralValue(context, expression.astLeft());
String right = findLiteralValue(context, expression.astRight());
if (left != null && right != null) {
return left + right;
}
}
} else {
ResolvedNode resolved = context.resolve(argument);
if (resolved instanceof ResolvedField) {
ResolvedField field = (ResolvedField) resolved;
Object value = field.getValue();
if (value instanceof String) {
return (String)value;
}
}
}
return null;
}
private static boolean checkWithinConditional(
@NonNull JavaContext context,
@Nullable Node curr,
@NonNull MethodInvocation logCall) {
while (curr != null) {
if (curr instanceof If) {
If ifNode = (If) curr;
if (ifNode.astCondition() instanceof MethodInvocation) {
MethodInvocation call = (MethodInvocation) ifNode.astCondition();
if (IS_LOGGABLE.equals(call.astName().astValue())) {
checkTagConsistent(context, logCall, call);
}
}
return true;
} else if (curr instanceof MethodInvocation
|| curr instanceof ClassDeclaration) { // static block
break;
}
curr = curr.getParent();
}
return false;
}
/** Checks that the tag passed to Log.s and Log.isLoggable match */
private static void checkTagConsistent(JavaContext context, MethodInvocation logCall,
MethodInvocation call) {
Iterator isLogIterator = call.astArguments().iterator();
Iterator logIterator = logCall.astArguments().iterator();
if (!isLogIterator.hasNext() || !logIterator.hasNext()) {
return;
}
Expression isLoggableTag = isLogIterator.next();
Expression logTag = logIterator.next();
//String callName = logCall.astName().astValue();
String logCallName = logCall.astName().astValue();
boolean isPrintln = PRINTLN.equals(logCallName);
if (isPrintln) {
if (!logIterator.hasNext()) {
return;
}
logTag = logIterator.next();
}
if (logTag != null) {
if (!isLoggableTag.toString().equals(logTag.toString())) {
ResolvedNode resolved1 = context.resolve(isLoggableTag);
ResolvedNode resolved2 = context.resolve(logTag);
if ((resolved1 == null || resolved2 == null || !resolved1.equals(resolved2))
&& context.isEnabled(WRONG_TAG)) {
Location location = context.getLocation(logTag);
Location alternate = context.getLocation(isLoggableTag);
alternate.setMessage("Conflicting tag");
location.setSecondary(alternate);
String isLoggableDescription = resolved1 != null ? resolved1
.getName()
: isLoggableTag.toString();
String logCallDescription = resolved2 != null ? resolved2.getName()
: logTag.toString();
String message = String.format(
"Mismatched tags: the `%1$s()` and `isLoggable()` calls typically " +
"should pass the same tag: `%2$s` versus `%3$s`",
logCallName,
isLoggableDescription,
logCallDescription);
context.report(WRONG_TAG, call, location, message);
}
}
}
// Check log level versus the actual log call type (e.g. flag
// if (Log.isLoggable(TAG, Log.DEBUG) Log.info(TAG, "something")
if (logCallName.length() != 1 || !isLogIterator.hasNext()) { // e.g. println
return;
}
Expression isLoggableLevel = isLogIterator.next();
if (isLoggableLevel == null) {
return;
}
String levelString = isLoggableLevel.toString();
if (isLoggableLevel instanceof Select) {
levelString = ((Select)isLoggableLevel).astIdentifier().astValue();
}
if (levelString.isEmpty()) {
return;
}
char levelChar = Character.toLowerCase(levelString.charAt(0));
if (logCallName.charAt(0) == levelChar || !context.isEnabled(WRONG_TAG)) {
return;
}
switch (levelChar) {
case 'd':
case 'e':
case 'i':
case 'v':
case 'w':
break;
default:
// Some other char; e.g. user passed in a literal value or some
// local constant or variable alias
return;
}
String expectedCall = String.valueOf(levelChar);
String message = String.format(
"Mismatched logging levels: when checking `isLoggable` level `%1$s`, the " +
"corresponding log call should be `Log.%2$s`, not `Log.%3$s`",
levelString, expectedCall, logCallName);
Location location = context.getLocation(logCall.astName());
Location alternate = context.getLocation(isLoggableLevel);
alternate.setMessage("Conflicting tag");
location.setSecondary(alternate);
context.report(WRONG_TAG, call, location, message);
}
}