Don't run inspections in extracted AAR folders

Most "outputs" (such as build/intermediates/) are marked as generated
source roots, which means IntelliJ won't scan those folders for
warnings.

However, AAR libraries are extracted into special build folders
(currently build/intermediates/exploded-aar) which are *not* marked as
generated; that's necessary such that those folders are scanned (for
indexing purposes), handled as potential go-to-declaration targets
(since resource files there can contain for example themes extended in
the user's application). Therefore, by default, IntelliJ will analyze
all the files in the exploded AAR folders. When you have large
libraries like appcompat or play services, this not only takes a lot
of extra time to analyze. You also end up with a lot of errors in
files you can't edit. For example, with appcompat, you end up with
over 700 spelling mistake warnings, and with play services, you end up
with over a hundred unused namespace warnings, and over a hundred tag
has no children warnings!

Therefore, this CL tweaks the batch analysis runner which iterates
over PSI files to skip files that are found to be within an AAR
folder. This removes all the false positives and speeds up code
analysis quite significantly!

Change-Id: I3dfdd663689a9d75de0318b03e5c4d8c3c6c30f6
(cherry picked from commit 771f728d65f218292649115c1130de00b8c37ec4)

1 files changed, 42 insertions, 0 deletions

diff --git a/platform/lang-impl/src/com/intellij/codeInspection/ex/GlobalInspectionContextImpl.java b/platform/lang-impl/src/com/intellij/codeInspection/ex/GlobalInspectionContextImpl.java
index 695c2a72d200..9bbaa278d207 100644
--- a/platform/lang-impl/src/com/intellij/codeInspection/ex/GlobalInspectionContextImpl.java
+++ b/platform/lang-impl/src/com/intellij/codeInspection/ex/GlobalInspectionContextImpl.java
@@ -310,6 +310,21 @@ public class GlobalInspectionContextImpl extends GlobalInspectionContextBase imp
     });
   }
 
+  // Android Studio: Is the given file a file we should ignore during batch inspections?
+  private static final String EXPLODED_AAR = "exploded-aar";
+  private static boolean isIgnoredFile(@NotNull PsiFile psiFile) {
+    VirtualFile file = psiFile.getVirtualFile();
+    while (file != null) {
+      if (EXPLODED_AAR.equals(file.getName())) {
+        return true;
+      } else {
+        file = file.getParent();
+      }
+    }
+
+    return false;
+  }
+
   @Override
   protected void runTools(@NotNull AnalysisScope scope, boolean runGlobalToolsOnly) {
     final InspectionManagerEx inspectionManager = (InspectionManagerEx)InspectionManager.getInstance(getProject());
@@ -343,6 +358,33 @@ public class GlobalInspectionContextImpl extends GlobalInspectionContextBase imp
           throw new ProcessCanceledException();
         }
 
+        // Android Studio tweak:
+        // Most "outputs" (such as build/intermediates/) are marked as generated
+        // source roots, which means IntelliJ won't scan those folders for
+        // warnings.
+        //
+        // However, AAR libraries are extracted into special build folders
+        // (currently build/intermediates/exploded-aar) which are *not* marked as
+        // generated; that's necessary such that those folders are scanned (for
+        // indexing purposes), handled as potential go-to-declaration targets
+        // (since resource files there can contain for example themes extended in
+        // the user's application). Therefore, by default, IntelliJ will analyze
+        // all the files in the exploded AAR folders. When you have large
+        // libraries like appcompat or play services, this not only takes a lot
+        // of extra time to analyze. You also end up with a lot of errors in
+        // files you can't edit. For example, with appcompat, you end up with
+        // over 700 spelling mistake warnings, and with play services, you end up
+        // with over a hundred unused namespace warnings, and over a hundred tag
+        // has no children warnings!
+        //
+        // Therefore, in the below  this CL tweaks the batch analysis runner which iterates
+        // over PSI files to skip files that are found to be within an AAR
+        // folder. This removes all the false positives and speeds up code
+        // analysis quite significantly!
+        if (isIgnoredFile(file)) {
+          return;
+        }
+
         if (LOG.isDebugEnabled()) {
           LOG.debug("Running local inspections on " + virtualFile.getPath());
         }