Add lint comment checker

Change-Id: I5ba847838e0035ab8ad44967779fdf814d1901a6

4 files changed, 266 insertions, 1 deletions

diff --git a/lint/libs/lint_checks/src/com/android/tools/lint/checks/BuiltinIssueRegistry.java b/lint/libs/lint_checks/src/com/android/tools/lint/checks/BuiltinIssueRegistry.java
index 3a40115..e521803 100644
--- a/lint/libs/lint_checks/src/com/android/tools/lint/checks/BuiltinIssueRegistry.java
+++ b/lint/libs/lint_checks/src/com/android/tools/lint/checks/BuiltinIssueRegistry.java
@@ -55,7 +55,7 @@ public class BuiltinIssueRegistry extends IssueRegistry {
     private static final List<Issue> sIssues;
 
     static {
-        final int initialCapacity = 126;
+        final int initialCapacity = 128;
         List<Issue> issues = new ArrayList<Issue>(initialCapacity);
 
         issues.add(AccessibilityDetector.ISSUE);
@@ -105,6 +105,8 @@ public class BuiltinIssueRegistry extends IssueRegistry {
         issues.add(HardcodedValuesDetector.ISSUE);
         issues.add(Utf8Detector.ISSUE);
         issues.add(DosLineEndingDetector.ISSUE);
+        issues.add(CommentDetector.EASTEREGG);
+        issues.add(CommentDetector.STOPSHIP);
         issues.add(ProguardDetector.WRONGKEEP);
         issues.add(ProguardDetector.SPLITCONFIG);
         issues.add(PxUsageDetector.PX_ISSUE);
diff --git a/lint/libs/lint_checks/src/com/android/tools/lint/checks/CommentDetector.java b/lint/libs/lint_checks/src/com/android/tools/lint/checks/CommentDetector.java
new file mode 100644
index 0000000..0e5d8d0
--- /dev/null
+++ b/lint/libs/lint_checks/src/com/android/tools/lint/checks/CommentDetector.java
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2012 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 com.android.annotations.NonNull;
+import com.android.tools.lint.detector.api.Category;
+import com.android.tools.lint.detector.api.Context;
+import com.android.tools.lint.detector.api.Detector;
+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 com.android.tools.lint.detector.api.Speed;
+
+import java.io.File;
+import java.util.Collections;
+import java.util.List;
+
+import lombok.ast.AstVisitor;
+import lombok.ast.Comment;
+import lombok.ast.ForwardingAstVisitor;
+import lombok.ast.Node;
+
+/**
+ * Looks for issues in Java comments
+ */
+public class CommentDetector extends Detector implements Detector.JavaScanner {
+    private static final String STOPSHIP_COMMENT = "STOPSHIP"; //$NON-NLS-1$
+
+    /** Looks for hidden code */
+    public static final Issue EASTEREGG = Issue.create(
+            "EasterEgg", //$NON-NLS-1$
+            "Looks for hidden easter eggs",
+            "An \"easter egg\" is code deliberately hidden in the code, both from potential " +
+            "users and even from other developers. This lint check looks for code which " +
+            "looks like it may be hidden from sight.",
+            Category.SECURITY,
+            6,
+            Severity.WARNING,
+            CommentDetector.class,
+            Scope.JAVA_FILE_SCOPE).setEnabledByDefault(false);
+
+    /** Looks for special comment markers intended to stop shipping the code */
+    public static final Issue STOPSHIP = Issue.create(
+            "StopShip", //$NON-NLS-1$
+            "Looks for comment markers of the form \"STOPSHIP\" which indicates that code " +
+            "should not be released yet",
+
+            "Using the comment `// STOPSHIP` can be used to flag code that is incomplete but " +
+            "checked in. This comment marker can be used to indicate that the code should not " +
+            "be shipped until the issue is addressed, and lint will look for these.",
+            Category.CORRECTNESS,
+            10,
+            Severity.WARNING,
+            CommentDetector.class,
+            Scope.JAVA_FILE_SCOPE).setEnabledByDefault(false);
+
+    private static final String ESCAPE_STRING = "\\u002a\\u002f"; //$NON-NLS-1$
+
+    /** Lombok's AST only passes comment nodes for Javadoc so I need to do manual token scanning
+         instead */
+    private static final boolean USE_AST = false;
+
+
+    /** Constructs a new {@link CommentDetector} check */
+    public CommentDetector() {
+    }
+
+    @Override
+    public boolean appliesTo(@NonNull Context context, @NonNull File file) {
+        return true;
+    }
+
+    @Override
+    public @NonNull Speed getSpeed() {
+        return Speed.NORMAL;
+    }
+
+    @Override
+    public List<Class<? extends Node>> getApplicableNodeTypes() {
+        if (USE_AST) {
+            return Collections.<Class<? extends Node>>singletonList(Comment.class);
+        } else {
+            return null;
+        }
+    }
+
+    @Override
+    public AstVisitor createJavaVisitor(@NonNull JavaContext context) {
+        // Lombok does not generate comment nodes for block and line comments, only for
+        // javadoc comments!
+        if (USE_AST) {
+            return new CommentChecker(context);
+        } else {
+            String source = context.getContents();
+            if (source == null) {
+                return null;
+            }
+            // Process the Java source such that we pass tokens to it
+
+            for (int i = 0, n = source.length() - 1; i < n; i++) {
+                char c = source.charAt(i);
+                if (c == '\\') {
+                    i += 1;
+                } else if (c == '/') {
+                    char next = source.charAt(i + 1);
+                    if (next == '/') {
+                        // Line comment
+                        int start = i + 2;
+                        int end = source.indexOf('\n', start);
+                        if (end == -1) {
+                            end = n;
+                        }
+                        checkComment(context, source, 0, start, end);
+                    } else if (next == '*') {
+                        // Block comment
+                        int start = i + 2;
+                        int end = source.indexOf("*/", start);
+                        if (end == -1) {
+                            end = n;
+                        }
+                        checkComment(context, source, 0, start, end);
+                    }
+                }
+            }
+            return null;
+        }
+    }
+
+    private static class CommentChecker extends ForwardingAstVisitor {
+        private final JavaContext mContext;
+
+        public CommentChecker(JavaContext context) {
+            mContext = context;
+        }
+
+        @Override
+        public boolean visitComment(Comment node) {
+            String contents = node.astContent();
+            checkComment(mContext, contents, node.getPosition().getStart(), 0, contents.length());
+            return super.visitComment(node);
+        }
+    }
+
+    private static void checkComment(
+            @NonNull Context context,
+            @NonNull String source,
+            int offset,
+            int start,
+            int end) {
+        char prev = 0;
+        char c = 0;
+        for (int i = start; i < end - 2; i++, prev = c) {
+            c = source.charAt(i);
+            if (prev == '\\') {
+                if (c == 'u' || c == 'U') {
+                    if (source.regionMatches(true, i - 1, ESCAPE_STRING,
+                            0, ESCAPE_STRING.length())) {
+                        Location location = Location.create(context.file, source,
+                                offset + i - 1, offset + i - 1 + ESCAPE_STRING.length());
+                        context.report(EASTEREGG, location,
+                                "Code might be hidden here; found unicode escape sequence " +
+                                "which is interpreted as comment end, compiled code follows",
+                                null);
+                    }
+                } else {
+                    i++;
+                }
+            } else if (prev == 'S' && c == 'T' &&
+                    source.regionMatches(i - 1, STOPSHIP_COMMENT, 0, STOPSHIP_COMMENT.length())) {
+                // TODO: Only flag this issue in release mode??
+                Location location = Location.create(context.file, source,
+                        offset + i - 1, offset + i - 1 + STOPSHIP_COMMENT.length());
+                context.report(STOPSHIP, location,
+                        "STOPSHIP comment found; points to code which must be fixed prior " +
+                        "to release",
+                        null);
+            }
+        }
+    }
+}
diff --git a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/CommentDetectorTest.java b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/CommentDetectorTest.java
new file mode 100644
index 0000000..c352962
--- /dev/null
+++ b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/CommentDetectorTest.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2012 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 com.android.tools.lint.detector.api.Detector;
+
+@SuppressWarnings("javadoc")
+public class CommentDetectorTest extends AbstractCheckTest {
+    @Override
+    protected Detector getDetector() {
+        return new CommentDetector();
+    }
+
+    public void test() throws Exception {
+        assertEquals(
+        "src/test/pkg/Hidden.java:11: Warning: STOPSHIP comment found; points to code which must be fixed prior to release [StopShip]\n" +
+        "    // STOPSHIP\n" +
+        "       ~~~~~~~~\n" +
+        "src/test/pkg/Hidden.java:12: Warning: STOPSHIP comment found; points to code which must be fixed prior to release [StopShip]\n" +
+        "    /* We must STOPSHIP! */\n" +
+        "               ~~~~~~~~\n" +
+        "src/test/pkg/Hidden.java:5: Warning: Code might be hidden here; found unicode escape sequence which is interpreted as comment end, compiled code follows [EasterEgg]\n" +
+        "    /* \\u002a\\u002f static { System.out.println(\"I'm executed on class load\"); } \\u002f\\u002a */\n" +
+        "       ~~~~~~~~~~~~\n" +
+        "src/test/pkg/Hidden.java:6: Warning: Code might be hidden here; found unicode escape sequence which is interpreted as comment end, compiled code follows [EasterEgg]\n" +
+        "    /* \\u002A\\U002F static { System.out.println(\"I'm executed on class load\"); } \\u002f\\u002a */\n" +
+        "       ~~~~~~~~~~~~\n" +
+        "0 errors, 4 warnings\n",
+
+        lintProject("src/test/pkg/Hidden.java.txt=>src/test/pkg/Hidden.java"));
+    }
+
+    public void test2() throws Exception {
+        assertEquals(
+        "No warnings.",
+
+        lintProject("src/test/pkg/SdCardTest.java.txt=>src/test/pkg/SdCardTest.java"));
+    }
+}
diff --git a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/src/test/pkg/Hidden.java.txt b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/src/test/pkg/Hidden.java.txt
new file mode 100644
index 0000000..847cd88
--- /dev/null
+++ b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/src/test/pkg/Hidden.java.txt
@@ -0,0 +1,14 @@
+package test.pkg;
+
+public class Hidden {
+    // Innocent comment...?
+    /* \u002a\u002f static { System.out.println("I'm executed on class load"); } \u002f\u002a */
+    /* \u002A\U002F static { System.out.println("I'm executed on class load"); } \u002f\u002a */
+    /* Normal \\u002A\U002F */ // OK
+    static {
+        String s = "\u002a\u002f"; // OK
+    }
+    // STOPSHIP
+    /* We must STOPSHIP! */
+    String x = "STOPSHIP"; // OK
+}