From 9062fab64c80b9f7de267867c2cfb111ec7db79b Mon Sep 17 00:00:00 2001
From: William Morgan <wmorgan@masanjin.net>
Date: Tue, 13 Dec 2011 11:43:09 -0800
Subject: [PATCH] steal platform-specific C++ config from eventmachine

It's in platform.rb.
---
 Rakefile                |  2 +-
 ext/leveldb/extconf.rb  |  8 +---
 ext/leveldb/platform.rb | 83 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 86 insertions(+), 7 deletions(-)
 create mode 100644 ext/leveldb/platform.rb

diff --git a/Rakefile b/Rakefile
index e759142..e146598 100644
--- a/Rakefile
+++ b/Rakefile
@@ -10,7 +10,7 @@ spec = Gem::Specification.new do |s|
  s.authors = ["William Morgan"]
  s.summary = "a Ruby binding to LevelDB"
  s.homepage = "http://github.com/wmorgan/leveldb-ruby"
- s.files = %w(README ext/leveldb/extconf.rb lib/leveldb.rb ext/leveldb/leveldb.cc leveldb/Makefile leveldb/build_detect_platform)
+ s.files = %w(README ext/leveldb/extconf.rb ext/leveldb/platform.rb lib/leveldb.rb ext/leveldb/leveldb.cc leveldb/Makefile leveldb/build_detect_platform)
  Find.find("leveldb") { |x| s.files << x if x =~ /\.(cc|h)$/}
  s.extensions = %w(ext/leveldb/extconf.rb)
  s.executables = []
diff --git a/ext/leveldb/extconf.rb b/ext/leveldb/extconf.rb
index 520bf84..5698bc1 100644
--- a/ext/leveldb/extconf.rb
+++ b/ext/leveldb/extconf.rb
@@ -1,18 +1,14 @@
 require 'mkmf'
 require 'fileutils'
+require "./platform.rb"
 
 Dir.chdir "../../leveldb"
 system "make libleveldb.a" or abort
 Dir.chdir "../ext/leveldb"
 
-CONFIG['LDSHARED'] = "$(CXX) -shared"
+set_platform_specific_variables!
 
 $CFLAGS << " -I../../leveldb/include"
 $LIBS << " -L../../leveldb -lleveldb"
-if RUBY_PLATFORM =~ /darwin/
-  $CFLAGS.sub! "-arch i386", ""
-  $LDFLAGS.sub! "-arch i386", ""
-  $LIBS << " -lruby" # whyyyyy
-end
 
 create_makefile "leveldb/leveldb"
diff --git a/ext/leveldb/platform.rb b/ext/leveldb/platform.rb
new file mode 100644
index 0000000..a5cb712
--- /dev/null
+++ b/ext/leveldb/platform.rb
@@ -0,0 +1,83 @@
+## here lies some platform-specific C++ compile and link environment
+## variable hacking.
+##
+## this code is entirely stolen from eventmachine's extconf.rb. many
+## thanks to @tmm1 for the pointer.
+
+def check_libs libs=[], fatal=false
+  libs.all? { |lib| have_library(lib) || (abort("could not find library: #{lib}") if fatal) }
+end
+
+def check_heads heads=[], fatal=false
+  heads.all? { |head| have_header(head) || (abort("could not find header: #{head}") if fatal)}
+end
+
+def add_define name; $defs.push "-D#{name}" end
+
+def set_platform_specific_variables!
+  puts "setting build environment for #{RUBY_PLATFORM}..."
+  case RUBY_PLATFORM
+  when /mswin32/, /mingw32/, /bccwin32/
+    check_heads(%w[windows.h winsock.h], true)
+    check_libs(%w[kernel32 rpcrt4 gdi32], true)
+
+    if GNU_CHAIN
+      CONFIG['LDSHARED'] = "$(CXX) -shared -lstdc++"
+    else
+      $defs.push "-EHs"
+      $defs.push "-GR"
+    end
+
+  when /solaris/
+    add_define 'OS_SOLARIS8'
+    check_libs(%w[nsl socket], true)
+
+    if CONFIG['CC'] == 'cc' and `cc -flags 2>&1` =~ /Sun/ # detect SUNWspro compiler
+      # SUN CHAIN
+      add_define 'CC_SUNWspro'
+      $preload = ["\nCXX = CC"] # hack a CXX= line into the makefile
+      $CFLAGS = CONFIG['CFLAGS'] = "-KPIC"
+      CONFIG['CCDLFLAGS'] = "-KPIC"
+      CONFIG['LDSHARED'] = "$(CXX) -G -KPIC -lCstd"
+    else
+      # GNU CHAIN
+      # on Unix we need a g++ link, not gcc.
+      CONFIG['LDSHARED'] = "$(CXX) -shared"
+    end
+
+  when /openbsd/
+    # OpenBSD branch contributed by Guillaume Sellier.
+
+    # on Unix we need a g++ link, not gcc. On OpenBSD, linking against libstdc++ have to be explicitly done for shared libs
+    CONFIG['LDSHARED'] = "$(CXX) -shared -lstdc++ -fPIC"
+    CONFIG['LDSHAREDXX'] = "$(CXX) -shared -lstdc++ -fPIC"
+
+  when /darwin/
+    # on Unix we need a g++ link, not gcc.
+    # Ff line contributed by Daniel Harple.
+    CONFIG['LDSHARED'] = "$(CXX) " + CONFIG['LDSHARED'].split[1..-1].join(' ')
+
+  when /linux/
+    add_define 'HAVE_EPOLL' if have_func('epoll_create', 'sys/epoll.h')
+
+    # on Unix we need a g++ link, not gcc.
+    CONFIG['LDSHARED'] = "$(CXX) -shared"
+
+  when /aix/
+    CONFIG['LDSHARED'] = "$(CXX) -shared -Wl,-G -Wl,-brtl"
+
+  when /cygwin/
+    # For rubies built with Cygwin, CXX may be set to CC, which is just
+    # a wrapper for gcc.
+    # This will compile, but it will not link to the C++ std library.
+    # Explicitly set CXX to use g++.
+    CONFIG['CXX'] = "g++"
+    # on Unix we need a g++ link, not gcc.
+    CONFIG['LDSHARED'] = "$(CXX) -shared"
+
+  else
+    # on Unix we need a g++ link, not gcc.
+    CONFIG['LDSHARED'] = "$(CXX) -shared"
+  end
+end
+