Experimental support for ios_framework rules

* Allows for building and linking to a framework in ios_application
* Currently only works for single arch builds
* Xcode generation produces correct target type, but is mostly untested

The implementation is very similar to that of objc_framework:

1) Build the ios_framework_binary as a dynamic library (-dynamiclib)

2) Symlink the library and public headers to a staging location, inside of "X.framework" bundle. Where X is the name under ios_framework_binary#framework_name

3) Pass the bundle content to ObjcCommon.addFrameworkImports, reusing the core of objc_framework rule implementation. This results in correctly set -F/-framework flags and allows clients to use the framework in a way they would use any SDK/3rd-party framework. It's allowed to import headers via #import <X/X.h> call.

4) Copy the binary and all resources into final application bundle under Frameworks/X.framework

5) Sign the app and nested frameworks

--
MOS_MIGRATED_REVID=100397239

1 files changed, 7 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java
index 1737c0de00..413ed2d5b2 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProvider.java
@@ -212,7 +212,13 @@ public final class ObjcProvider implements TransitiveInfoProvider {
      * Indicates that Swift source files are present. This affects bundling, compiling and linking
      * actions.
      */
-    USES_SWIFT
+    USES_SWIFT,
+
+    /**
+     * Indicates that the resulting bundle will have embedded frameworks. This affects linking step.
+     */
+    USES_FRAMEWORKS
+
   }
 
   private final ImmutableMap<Key<?>, NestedSet<?>> items;