Generate Android shared library list automatically

* .gitignore: Ignore new generated files.

* cross/Makefile.in (src/Makefile): Remove leftover
specification of the source Gnulib directory.

* cross/ndk-build/ndk-build.mk.in (NDK_BUILD_READELF): New
variable.

* java/Makefile.in (CONFIG_FILE, ALL_DEPENDENCIES, READELF)
(cf-stamp-1, cf-stamp): New variables and rules; compute the set
of library files in the order of loading and generate a file
with this information.
(ALL_CLASS_FILES): New variable; if builddir is not srcdir,
$($(CONFIG_FILE), $(CLASS_FILES)): Depend on EmacsConfig.java.
add generated files in the build directory.
(classes.dex): Adjust to match.

* java/org/gnu/emacs/EmacsNative.java (EmacsNative)
<static initializer>: Load shared libraries from
EMACS_SHARED_LIBRARIES rather than a hard-coded list.

* m4/ndk-build.m4 (ndk_INIT): Search for readelf...
(ndk_CHECK_MODULES): ...and substitute its path as
NDK_BUILD_READELF.

1 files changed, 24 insertions, 28 deletions

diff --git a/java/org/gnu/emacs/EmacsNative.java b/java/org/gnu/emacs/EmacsNative.java
index 567242f2ec3..9b3e60e1a84 100644
--- a/java/org/gnu/emacs/EmacsNative.java
+++ b/java/org/gnu/emacs/EmacsNative.java
@@ -321,39 +321,35 @@ public final class EmacsNative
 
   static
   {
-    /* Older versions of Android cannot link correctly with shared
-       libraries that link with other shared libraries built along
-       Emacs unless all requisite shared libraries are explicitly
-       loaded from Java.
-
-       Every time you add a new shared library dependency to Emacs,
-       please insert it here as well, before other shared libraries of
-       which it might be a dependency.  */
-
-    libraryDeps = new String[] { "c++_shared", "gnustl_shared",
-                                 "stlport_shared", "gabi++_shared",
-                                 "png_emacs", "pcre_emacs",
-                                 "selinux_emacs", "crypto_emacs",
-                                 "packagelistparser_emacs",
-                                 "gmp_emacs", "nettle_emacs",
-                                 "p11-kit_emacs", "tasn1_emacs",
-                                 "hogweed_emacs", "gnutls_emacs",
-                                 "jpeg_emacs", "tiff_emacs",
-                                 "icuuc_emacs", "xml2_emacs",
-                                 "harfbuzz_emacs", "tree-sitter_emacs", };
+    /* A library search path misconfiguration prevents older versions of
+       Android from successfully loading application shared libraries
+       unless all requisite shared libraries provided by the application
+       are explicitly loaded from Java.  The build process arranges that
+       EmacsConfig.EMACS_SHARED_LIBRARIES hold the names of each of
+       these libraries in the correct order, so load them now.  */
+
+    libraryDeps = EmacsConfig.EMACS_SHARED_LIBRARIES;
 
     for (String dependency : libraryDeps)
       {
-        try
-          {
-            System.loadLibrary (dependency);
-          }
-        catch (UnsatisfiedLinkError exception)
-          {
-            /* Ignore this exception.  */
-          }
+        /* Remove the "lib" prefix, if any.  */
+        if (dependency.startsWith ("lib"))
+          dependency = dependency.substring (3);
+
+        /* If this library is provided by the operating system, don't
+           link to it.  */
+        if (dependency.equals ("z")
+            || dependency.equals ("c")
+            || dependency.equals ("m")
+            || dependency.equals ("dl")
+            || dependency.equals ("log")
+            || dependency.equals ("android"))
+          continue;
+
+        System.loadLibrary (dependency);
       }
 
+    /* At this point, it should be alright to load Emacs.  */
     System.loadLibrary ("emacs");
   };
 };