Sqlite: Add option for contributed functions

Closes #6939.

Signed-off-by: Charlie Sharpsteen <source@sharpsteen.net>

Library/Formula/sqlite.rb

@@ -1,25 +1,63 @@
 require 'formula'
 
+class SqliteFunctions < Formula
+  url 'http://www.sqlite.org/contrib/download/extension-functions.c?get=25', :using  => NoUnzipCurlDownloadStrategy
+  md5 '3a32bfeace0d718505af571861724a43'
+  version '2010-01-06'
+end
+
 class Sqlite < Formula
   homepage 'http://sqlite.org/'
-  url 'http://www.sqlite.org/sqlite-autoconf-3070700.tar.gz'
-  md5 'a98df57053adf4c132b6b7ab59e9f333'
-  version '3.7.7'
+  url 'http://www.sqlite.org/sqlite-autoconf-3070701.tar.gz'
+  md5 '554026fe7fac47b1cf61c18d5fe43419'
+  version '3.7.7.1'
 
   def options
   [
     ["--with-rtree", "Enables the R*Tree index module"],
     ["--with-fts", "Enables the FTS Module"],
-    ["--universal", "Build a universal binary."]
+    ["--universal", "Build a universal binary."],
+    ["--with-functions", "Enables more math and string functions for SQL queries."]
   ]
   end
 
   def install
     ENV.append "CFLAGS", "-DSQLITE_ENABLE_RTREE=1" if ARGV.include? "--with-rtree"
     ENV.append "CPPFLAGS","-DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_FTS3_PARENTHESIS" if ARGV.include? "--with-fts"
     ENV.universal_binary if ARGV.build_universal?
-    system "./configure", "--prefix=#{prefix}",
-                          "--disable-dependency-tracking"
+
+    system "./configure", "--prefix=#{prefix}", "--disable-dependency-tracking",
+                          (ARGV.include? "--with-functions") ? "--enable-dynamic-extensions" : ""
     system "make install"
+
+    if ARGV.include? "--with-functions"
+      d=Pathname.getwd
+      SqliteFunctions.new.brew { mv 'extension-functions.c?get=25', d + 'extension-functions.c' }
+      system ENV.cc, "-fno-common", "-dynamiclib", "extension-functions.c", "-o", "libsqlitefunctions.dylib", *ENV.cflags.split
+      lib.install "libsqlitefunctions.dylib"
+    end
+  end
+
+  if ARGV.include? "--with-functions"
+    def caveats
+      <<-EOS.undent
+        Usage instructions for applications calling the sqlite3 API functions:
+
+          In your application, call sqlite3_enable_load_extension(db,1) to
+          allow loading external libraries.  Then load the library libsqlitefunctions
+          using sqlite3_load_extension; the third argument should be 0.
+          See http://www.sqlite.org/cvstrac/wiki?p=LoadableExtensions.
+          Select statements may now use these functions, as in
+          SELECT cos(radians(inclination)) FROM satsum WHERE satnum = 25544;
+
+        Usage instructions for the sqlite3 program:
+
+          If the program is built so that loading extensions is permitted,
+          the following will work:
+           sqlite> SELECT load_extension('#{lib}/libsqlitefunctions.dylib');
+           sqlite> select cos(radians(45));
+           0.707106781186548
+      EOS
+    end
   end
 end