Include report of unscannable files in MissingLibraryException

relinker/src/main/java/com/getkeepsafe/relinker/AbiSupportInfo.java

@@ -0,0 +1,35 @@
+package com.getkeepsafe.relinker;
+
+import java.io.File;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Set;
+
+public class AbiSupportInfo {
+    private final Set<String> supportedAbis;
+    private final Map<File, Exception> unScannableFileAndReasons;
+
+    public AbiSupportInfo(Set<String> supportedAbis) {
+        this(supportedAbis, Collections.emptyMap());
+    }
+
+    public AbiSupportInfo(Set<String> supportedAbis, Map<File, Exception> unscannableFilesAndReasons) {
+        this.supportedAbis = supportedAbis;
+        this.unScannableFileAndReasons = unscannableFilesAndReasons;
+    }
+
+    public String[] getSupportedAbis() {
+        String[] arr = new String[supportedAbis.size()];
+        supportedAbis.toArray(arr);
+        return arr;
+    }
+
+    public String[] getUnscannableFileNameAndReasons() {
+        String[] arr = new String[unScannableFileAndReasons.size()];
+        int i = 0;
+        for (Map.Entry<File, Exception> entry : unScannableFileAndReasons.entrySet()) {
+            arr[i++] = entry.getKey().getName() + " => " + entry.getValue();
+        }
+        return arr;
+    }
+}

relinker/src/main/java/com/getkeepsafe/relinker/ActualZipFileFactory.java

@@ -0,0 +1,12 @@
+package com.getkeepsafe.relinker;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.zip.ZipFile;
+
+public class ActualZipFileFactory implements ZipFileFactory {
+    @Override
+    public ZipFile create(File file, int openMode) throws IOException {
+        return new ZipFile(file, openMode);
+    }
+}

relinker/src/main/java/com/getkeepsafe/relinker/ApkLibraryInstaller.java

@@ -27,8 +27,11 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.Collections;
 import java.util.Enumeration;
+import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Map;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -39,6 +42,16 @@ public class ApkLibraryInstaller implements ReLinker.LibraryInstaller {
     private static final int MAX_TRIES = 5;
     private static final int COPY_BUFFER_SIZE = 4096;
 
+    private final ZipFileFactory zipFileFactory;
+
+    ApkLibraryInstaller() {
+        this(new ActualZipFileFactory());
+    }
+
+    ApkLibraryInstaller(ZipFileFactory zipFileFactory) {
+        this.zipFileFactory = zipFileFactory;
+    }
+
     private String[] sourceDirectories(final Context context) {
         final ApplicationInfo appInfo = context.getApplicationInfo();
 
@@ -74,7 +87,7 @@ private ZipFileInZipEntry findAPKWithLibrary(final Context context,
             int tries = 0;
             while (tries++ < MAX_TRIES) {
                 try {
-                    zipFile = new ZipFile(new File(sourceDir), ZipFile.OPEN_READ);
+                    zipFile = zipFileFactory.create(new File(sourceDir), ZipFile.OPEN_READ);
                     break;
                 } catch (IOException ignored) {
                 }
@@ -116,15 +129,18 @@ private ZipFileInZipEntry findAPKWithLibrary(final Context context,
     // This second loop is more expensive than trying to find a specific ABI, so it should
     // only be ran when no matching libraries are found. This should keep the overhead of
     // the happy path to a minimum.
-    private String[] getSupportedABIs(Context context, String mappedLibraryName) {
+    private AbiSupportInfo getSupportedABIs(Context context, String mappedLibraryName) {
         String p = "lib" + File.separatorChar + "([^\\" + File.separatorChar + "]*)" + File.separatorChar + mappedLibraryName;
         Pattern pattern = Pattern.compile(p);
         ZipFile zipFile;
         Set<String> supportedABIs = new HashSet<String>();
+        Map<File, Exception> unscannableFiles = new HashMap<File, Exception>();
         for (String sourceDir : sourceDirectories(context)) {
+            File source = new File(sourceDir);
             try {
-                zipFile = new ZipFile(new File(sourceDir), ZipFile.OPEN_READ);
-            } catch (IOException ignored) {
+                zipFile = zipFileFactory.create(source, ZipFile.OPEN_READ);
+            } catch (IOException e) {
+                unscannableFiles.put(source, e);
                 continue;
             }
 
@@ -138,8 +154,7 @@ private String[] getSupportedABIs(Context context, String mappedLibraryName) {
             }
         }
 
-        String[] result = new String[supportedABIs.size()];
-        return supportedABIs.toArray(result);
+        return new AbiSupportInfo(supportedABIs, unscannableFiles);
     }
 
     /**
@@ -163,14 +178,13 @@ public void installLibrary(final Context context,
             if (found == null) {
                 // Does not exist in any APK. Report exactly what ReLinker is looking for and
                 // what is actually supported by the APK.
-                String[] supportedABIs;
+                AbiSupportInfo supportedABIs;
                 try {
                     supportedABIs = getSupportedABIs(context, mappedLibraryName);
                 } catch (Exception e) {
                     // Should never happen as this indicates a bug in ReLinker code, but just to be safe.
                     // User code should only ever crash with a MissingLibraryException if getting this far.
-                    supportedABIs = new String[1];
-                    supportedABIs[0] = e.toString();
+                    supportedABIs = new AbiSupportInfo(Collections.singleton(e.toString()));
                 }
                 throw new MissingLibraryException(mappedLibraryName, abis, supportedABIs);
             }

relinker/src/main/java/com/getkeepsafe/relinker/MissingLibraryException.java

@@ -18,9 +18,28 @@
 import java.util.Arrays;
 
 public class MissingLibraryException extends RuntimeException {
-    public MissingLibraryException(final String library, final String[] wantedABIs, final String[] supportedABIs) {
-        super("Could not find '" + library + "'. " +
-                "Looked for: " + Arrays.toString(wantedABIs) + ", " +
-                "but only found: " + Arrays.toString(supportedABIs) + ".");
+    private final String library;
+    private final String[] wantedABIs;
+    private final AbiSupportInfo abiSupportInfo;
+
+    public MissingLibraryException(String library, String[] wantedABIs, AbiSupportInfo abiSupportInfo) {
+        this.library = library;
+        this.wantedABIs = wantedABIs;
+        this.abiSupportInfo = abiSupportInfo;
+    }
+
+    @Override
+    public String getMessage() {
+        StringBuilder sb = new StringBuilder();
+        sb.append("Could not find '").append(library).append("'. ");
+        sb.append("Looked for: ").append(Arrays.toString(wantedABIs)).append(", ");
+        sb.append("but only found: ").append(Arrays.toString(abiSupportInfo.getSupportedAbis())).append(".");
+
+        String[] unscannableFileNames = abiSupportInfo.getUnscannableFileNameAndReasons();
+        if (unscannableFileNames.length != 0) {
+            sb.append(" Additionally, encountered errors while scanning: ").append(Arrays.toString(unscannableFileNames)).append(".");
+        }
+
+        return sb.toString();
     }
 }

relinker/src/main/java/com/getkeepsafe/relinker/ZipFileFactory.java

@@ -0,0 +1,9 @@
+package com.getkeepsafe.relinker;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.zip.ZipFile;
+
+public interface ZipFileFactory {
+    ZipFile create(File file, int openMode) throws IOException;
+}

relinker/src/test/java/com/getkeepsafe/relinker/ApkLibraryInstallerTest.java

@@ -80,6 +80,25 @@ public void throwsMissingLibraryExceptionWhenABIIsMissing() throws IOException {
         }
     }
 
+    @Test
+    public void throwsMissingLibraryExceptionWhenABIIsMissingAndThereWereUnscannableDirs() throws IOException {
+        final Context context = mock(Context.class);
+        final ApplicationInfo appInfo = mock(ApplicationInfo.class);
+        final ReLinkerInstance instance = mock(ReLinkerInstance.class);
+        final ApkLibraryInstaller installer = new ApkLibraryInstaller(new FaultyZipFileFactory());
+        final File destination = tempFolder.newFile("test");
+        final String[] abis = new String[] {"armeabi-v7a"}; // For unit test running on a developer machine this is normally x86
+
+        when(context.getApplicationInfo()).thenReturn(appInfo);
+        appInfo.sourceDir = getClass().getResource("/fake.apk").getFile();
+
+        try {
+            installer.installLibrary(context, abis, "libtest.so", destination, instance);
+        } catch (MissingLibraryException e) {
+            assertEquals("Could not find 'libtest.so'. Looked for: [armeabi-v7a], but only found: []. Additionally, encountered errors while scanning: [fake.apk => java.io.IOException: Could not create zip file.].", e.getMessage());
+        }
+    }
+
     private String fileToString(final File file) throws IOException {
         final long size = file.length();
         if (size > Integer.MAX_VALUE) {

relinker/src/test/java/com/getkeepsafe/relinker/FaultyZipFileFactory.java

@@ -0,0 +1,12 @@
+package com.getkeepsafe.relinker;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.zip.ZipFile;
+
+public class FaultyZipFileFactory implements ZipFileFactory {
+    @Override
+    public ZipFile create(File file, int openMode) throws IOException {
+        throw new IOException("Could not create zip file.");
+    }
+}