Don't flag missing classes if project has not been built yet

The missing class detector in lint will warn if the manifest file
contains references to class files and lint does not see those class
files in the class output folder (or in any of the library jars).
This is useful for catching typos and deleted classes.

However, if you run lint on a project that has not yet been built,
this can give misleading or confusing errors, since lint decides that
a class exists by whether a .class file is actually there, not by
whether a source file exists which would result in a class file
getting produced with that name.

Change-Id: I3105157a37f575e00b550ba90d883f24c02c16a9

2 files changed, 19 insertions, 1 deletions

diff --git a/lint/libs/lint_checks/src/com/android/tools/lint/checks/MissingClassDetector.java b/lint/libs/lint_checks/src/com/android/tools/lint/checks/MissingClassDetector.java
index d4f4e95..ca7e33a 100644
--- a/lint/libs/lint_checks/src/com/android/tools/lint/checks/MissingClassDetector.java
+++ b/lint/libs/lint_checks/src/com/android/tools/lint/checks/MissingClassDetector.java
@@ -114,6 +114,7 @@ public class MissingClassDetector extends LayoutDetector implements ClassScanner
         Scope.MANIFEST_SCOPE);
 
     private Map<String, Location.Handle> mReferencedClasses;
+    private boolean mHaveClasses;
 
     /** Constructs a new {@link MissingClassDetector} */
     public MissingClassDetector() {
@@ -209,7 +210,7 @@ public class MissingClassDetector extends LayoutDetector implements ClassScanner
 
     @Override
     public void afterCheckProject(@NonNull Context context) {
-        if (!context.getProject().isLibrary()
+        if (!context.getProject().isLibrary() && mHaveClasses
                 && mReferencedClasses != null && !mReferencedClasses.isEmpty()
                 && context.getDriver().getScope().contains(Scope.CLASS_FILE)) {
             List<String> classes = new ArrayList<String>(mReferencedClasses.keySet());
@@ -244,6 +245,7 @@ public class MissingClassDetector extends LayoutDetector implements ClassScanner
 
     @Override
     public void checkClass(@NonNull ClassContext context, @NonNull ClassNode classNode) {
+        mHaveClasses = true;
         String curr = classNode.name;
         if (mReferencedClasses != null && mReferencedClasses.containsKey(curr)) {
             mReferencedClasses.remove(curr);
diff --git a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/MissingClassDetectorTest.java b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/MissingClassDetectorTest.java
index cda68a1..3c6e8cb 100644
--- a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/MissingClassDetectorTest.java
+++ b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/MissingClassDetectorTest.java
@@ -60,6 +60,7 @@ public class MissingClassDetectorTest extends AbstractCheckTest {
 
             lintProject(
                 "bytecode/AndroidManifestWrongRegs.xml=>AndroidManifest.xml",
+                "apicheck/ApiCallTest.class.data=>bin/classes/foo/bar/ApiCallTest.class",
                 "bytecode/.classpath=>.classpath"
             ));
     }
@@ -67,6 +68,17 @@ public class MissingClassDetectorTest extends AbstractCheckTest {
     public void testIncrementalInManifest() throws Exception {
         mScopes = Scope.MANIFEST_SCOPE;
         assertEquals(
+                "No warnings.",
+
+                lintProject(
+                    "bytecode/AndroidManifestWrongRegs.xml=>AndroidManifest.xml",
+                    "bytecode/.classpath=>.classpath"
+                ));
+    }
+
+    public void testNoWarningBeforeBuild() throws Exception {
+        mScopes = null;
+        assertEquals(
             "No warnings.",
 
             lintProject(
@@ -187,6 +199,7 @@ public class MissingClassDetectorTest extends AbstractCheckTest {
             lintProject(
                 "registration/AndroidManifest.xml=>AndroidManifest.xml",
                 "bytecode/.classpath=>.classpath",
+                "apicheck/ApiCallTest.class.data=>bin/classes/foo/bar/ApiCallTest.class",
                 "registration/Foo.java.txt=>src/test/pkg/Foo.java"
             ));
     }
@@ -202,6 +215,7 @@ public class MissingClassDetectorTest extends AbstractCheckTest {
             lintProject(
                 "registration/AndroidManifestInner.xml=>AndroidManifest.xml",
                 "bytecode/.classpath=>.classpath",
+                "apicheck/ApiCallTest.class.data=>bin/classes/foo/bar/ApiCallTest.class",
                 "registration/Bar.java.txt=>src/test/pkg/Foo/Bar.java"
             ));
     }
@@ -217,6 +231,7 @@ public class MissingClassDetectorTest extends AbstractCheckTest {
             lintProject(
                 "registration/AndroidManifestWrong.xml=>AndroidManifest.xml",
                 "bytecode/.classpath=>.classpath",
+                "apicheck/ApiCallTest.class.data=>bin/classes/foo/bar/ApiCallTest.class",
                 "registration/Bar.java.txt=>src/test/pkg/Foo/Bar.java"
             ));
     }
@@ -235,6 +250,7 @@ public class MissingClassDetectorTest extends AbstractCheckTest {
             lintProject(
                 "registration/AndroidManifestWrong2.xml=>AndroidManifest.xml",
                 "bytecode/.classpath=>.classpath",
+                "apicheck/ApiCallTest.class.data=>bin/classes/foo/bar/ApiCallTest.class",
                 "registration/Bar.java.txt=>src/test/pkg/Foo/Bar.java"
             ));
     }