Added optional .a linkage for libraries

Author: NicoHood

arduino-core/src/processing/app/debug/Compiler.java

@@ -1070,8 +1070,76 @@ private void compileLibrary(UserLibrary lib, List<File> includeFolders)
     if (lib.useRecursion()) {
       // libBuildFolder == {build.path}/LibName
       // libFolder      == {lib.path}/src
-      recursiveCompileFilesInFolder(libBuildFolder, libFolder, includeFolders);
-      
+
+      // Compile the library with .a linkage if a flag was set in library.properties
+      if(lib.alinkage()){
+
+          File afile = new File(libBuildFolder, lib.getName() + ".a");
+
+          createFolder(libBuildFolder);
+          List<File> libraryObjectFiles = compileFiles(libBuildFolder, libFolder, true, includeFolders);
+
+          // See if the .a file is already uptodate
+          if (afile.exists()) {
+            boolean changed = false;
+            for (File file : libraryObjectFiles) {
+              if (file.lastModified() > afile.lastModified()) {
+                changed = true;
+                break;
+              }
+            }
+
+            // If none of the object files is newer than the .a file, don't
+            // bother rebuilding the .a file. There is a small corner case
+            // here: If a source file was removed, but no other source file
+            // was modified, this will not rebuild core.a even when it
+            // should. It's hard to fix and not a realistic case, so it
+            // shouldn't be a problem.
+            if (!changed) {
+              if (verbose)
+                System.out.println(I18n.format(tr("Using previously compiled file: {0}"), afile.getPath()));
+
+                // this is no longer an object file, but will be added anyways.
+                objectFiles.add(afile);
+              return;
+            }
+          }
+
+          // Delete the .a file, to prevent any previous code from lingering
+          afile.delete();
+
+          try {
+            for (File file : libraryObjectFiles) {
+              PreferencesMap dict = new PreferencesMap(prefs);
+              dict.put("ide_version", "" + BaseNoGui.REVISION);
+              dict.put("archive_file", afile.getName());
+              dict.put("object_file", file.getAbsolutePath());
+              dict.put("build.path", libBuildFolder.getAbsolutePath());
+
+              String[] cmdArray;
+              String cmd = prefs.getOrExcept("recipe.ar.pattern");
+              try {
+                cmdArray = StringReplacer.formatAndSplit(cmd, dict, true);
+              } catch (Exception e) {
+                throw new RunnerException(e);
+              }
+              execAsynchronously(cmdArray);
+            }
+
+          } catch (RunnerException e) {
+            afile.delete();
+            throw e;
+          }
+
+          // this is no longer an object file, but will be added anyways.
+          objectFiles.add(afile);
+      }
+
+      // no alinkage, old, default .o file linkage
+      else{
+        recursiveCompileFilesInFolder(libBuildFolder, libFolder, includeFolders);
+      }
+
     } else {
       // libFolder          == {lib.path}/
       // utilityFolder      == {lib.path}/utility

arduino-core/src/processing/app/packages/UserLibrary.java

@@ -58,6 +58,7 @@ public class UserLibrary extends ContributedLibrary {
   private List<String> types;
   private List<String> declaredTypes;
   private boolean onGoingDevelopment;
+  private boolean alinkage;
 
   private static final List<String> MANDATORY_PROPERTIES = Arrays
     .asList("name", "version", "author", "maintainer",
@@ -154,6 +155,12 @@ public static UserLibrary create(File libFolder) throws IOException {
       typesList.add(type.trim());
     }
 
+    String alinkageString = properties.get("alinkage");
+    boolean alinkage = false;
+    if(alinkageString != null && alinkageString.equals("true")) {
+      alinkage = true;
+    }
+
     UserLibrary res = new UserLibrary();
     res.setInstalledFolder(libFolder);
     res.setInstalled(true);
@@ -170,6 +177,7 @@ public static UserLibrary create(File libFolder) throws IOException {
     res.layout = layout;
     res.declaredTypes = typesList;
     res.onGoingDevelopment = Files.exists(Paths.get(libFolder.getAbsolutePath(), Constants.LIBRARY_DEVELOPMENT_FLAG_FILE));
+    res.alinkage = alinkage;
     return res;
   }
 
@@ -274,6 +282,10 @@ public boolean onGoingDevelopment() {
     return onGoingDevelopment;
   }
 
+  public boolean alinkage() {
+    return alinkage;
+  }
+
   protected enum LibraryLayout {
     FLAT, RECURSIVE
   }