Prefer system yajl.

ext/yajl/encoder.c

@@ -1,5 +1,5 @@
 #include "common.h"
-#include "api/yajl_gen.h"
+#include "yajl_gen.h"
 
 #define WRITE_BUFSIZE 8192
 #define GetEncoder(obj, sval) (sval = (yajl_encoder_wrapper*)DATA_PTR(obj));

ext/yajl/extconf.rb

@@ -1,16 +1,27 @@
 require 'mkmf'
 
-yajl_dir = File.expand_path('../vendor', __FILE__)
 
-$CFLAGS << " -Wall -I#{yajl_dir}"
+$CFLAGS << " -Wall"
 $CFLAGS << ' -Wextra -O0 -ggdb3' if ENV['DEBUG']
 
-srcs = Dir[File.join(yajl_dir, '*.c')] + Dir[File.join(File.expand_path('..', __FILE__), '*.c')]
-$objs = srcs.map {|src| File.basename(src).gsub(/\.c$/, '.o') }
+def find_yajl_headers(path)
+  ['yajl_gen.h', 'yajl_parse.h'].each do |header|
+    find_header(header, path)
+  end
+end
 
-create_makefile('yajl/yajl')
+if have_library("yajl", nil, 'yajl/yajl_common.h')
+  find_yajl_headers(File.join($hdrdir, 'yajl'))
+else
+  yajl_dir = File.join($srcdir, 'vendor')
+
+  srcs = Dir[File.join(yajl_dir, '*.c')] + Dir[File.join(File.expand_path('..', __FILE__), '*.c')]
+  $objs = srcs.map {|src| File.basename(src).gsub(/\.c$/, '.o') }
+
+  $INCFLAGS << " -I#{yajl_dir}"
+  $VPATH << "$(srcdir)/vendor"
 
-# now lets post-process the Makefile so we compile the vendored yajl too
-m = File.read('Makefile')
-m.gsub!(/VPATH = (.*)\n/, "VPATH = \\1#{CONFIG['PATH_SEPARATOR']}#{yajl_dir}\n")
-File.open('Makefile', 'w+') {|f| f.write(m) }
+  find_yajl_headers(File.join(yajl_dir, 'api'))
+end
+
+create_makefile('yajl/yajl')

ext/yajl/parser.c

@@ -1,5 +1,5 @@
 #include "common.h"
-#include "api/yajl_parse.h"
+#include "yajl_parse.h"
 
 #define READ_BUFSIZE 8192
 #define GetParser(obj, sval) (sval = (yajl_parser_wrapper*)DATA_PTR(obj));
@@ -420,4 +420,4 @@ void _yajl_ruby_init_parser() {
 	sym_allow_comments = ID2SYM(rb_intern("allow_comments"));
 	sym_check_utf8 = ID2SYM(rb_intern("check_utf8"));
 	sym_symbolize_keys = ID2SYM(rb_intern("symbolize_keys"));
-}
+}