From 5d21dc9d5c7b742ebf21568e8b14e0b9da3eadb3 Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Wed, 1 Apr 2015 18:23:27 +0800
Subject: [PATCH 01/14] Split the library path detection logic by platform.

---
 ext/mysql2/extconf.rb | 387 +++++++++++++++++++++++++-----------------
 1 file changed, 228 insertions(+), 159 deletions(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index e38193d53..c03ce985b 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -1,17 +1,161 @@
 # encoding: UTF-8
 require 'mkmf'
-require 'English'
 
-def asplode(lib)
-  if RUBY_PLATFORM =~ /mingw|mswin/
-    abort "-----\n#{lib} is missing. Check your installation of MySQL or Connector/C, and try again.\n-----"
-  elsif RUBY_PLATFORM =~ /darwin/
-    abort "-----\n#{lib} is missing. You may need to 'brew install mysql' or 'port install mysql', and try again.\n-----"
-  else
-    abort "-----\n#{lib} is missing. You may need to 'apt-get install libmysqlclient-dev' or 'yum install mysql-devel', and try again.\n-----"
+class Platform
+  # Gets the proper platform object for the current platform.
+  def self.current
+    case RUBY_PLATFORM
+      when /mswin|mingw/
+        Windows.new
+      when /darwin/
+        MacOS.new
+      else
+        Linux.new
+    end
+  end
+
+  # @return [(String, String)|nil] The include and library paths.
+  def detect_paths
+    detect_by_explicit_path || detect_by_mysql_config
+  end
+
+  protected
+
+  def detect_by_explicit_path
+    # If the user has provided a --with-mysql-dir argument, we must respect it or fail.
+    inc, lib = dir_config('mysql')
+    if inc && lib
+      # Ruby versions not incorporating the mkmf fix at
+      # https://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/39717
+      # do not properly search for lib directories, and must be corrected
+      unless lib && lib[-3, 3] == 'lib'
+        @libdir_basename = 'lib'
+        inc, lib = dir_config('mysql')
+      end
+
+      error "Cannot find include dir(s) #{inc}" unless inc && inc.split(File::PATH_SEPARATOR).any?{|dir| File.directory?(dir)}
+      error "Cannot find library dir(s) #{lib}" unless lib && lib.split(File::PATH_SEPARATOR).any?{|dir| File.directory?(dir)}
+      warn  "Using --with-mysql-dir=#{File.dirname(inc)}"
+      [inc, lib]
+    else
+      nil
+    end
+  end
+
+  def detect_by_mysql_config
+    if with_config('mysql-config') && !mysql_config_path
+      error 'Cannot find mysql_config'
+    end
+    warn  "Using mysql_config at #{mysql_config_path}"
+
+    ver = `#{mysql_config_path} --version`.chomp.to_f
+    includes = `#{mysql_config_path} --include`.chomp
+    exit 1 if $? != 0
+    libs = `#{mysql_config_path} --libs_r`.chomp
+
+    # MySQL 5.5 and above already have re-entrant code in libmysqlclient (no _r).
+    if ver >= 5.5 || libs.empty?
+      libs = `#{mysql_config_path} --libs`.chomp
+    end
+    exit 1 if $? != 0
+
+    $INCFLAGS += ' ' + includes
+    $libs = "#{libs} #{$libs}"
+    [includes, libs]
+  end
+
+  def error(message)
+    abort("-----\n#{message}\n-----")
+  end
+
+  def warn(message)
+    super("-----\n#{message}\n-----")
+  end
+
+  def asplode(library)
+    complain("#{library} is missing. #{asplode_suggestion}")
+  end
+
+  def asplode_suggestion
+    'Please check your installation of MySQL and try again.'
+  end
+
+  def mysql_config_path
+    nil
   end
 end
 
+class Unix < Platform
+  # borrowed from mysqlplus
+  # http://github.com/oldmoe/mysqlplus/blob/master/ext/extconf.rb
+  DEFAULT_MYSQL_CONFIG_SEARCH_PATHS = %w[
+    /opt
+    /opt/local
+    /opt/local/mysql
+    /opt/local/lib/mysql5*
+    /usr
+    /usr/mysql
+    /usr/local
+    /usr/local/mysql
+    /usr/local/mysql-*
+    /usr/local/lib/mysql5*
+  ].freeze
+
+  def detect_paths
+    super || detect_by_known_paths
+  end
+
+  protected
+
+  def detect_by_known_paths
+    inc, lib = dir_config('mysql', '/usr/local')
+    libs = ['m', 'z', 'socket', 'nsl', 'mygcc']
+    found = false
+    until find_library('mysqlclient', 'mysql_query', lib, "#{lib}/mysql") do
+      break if libs.empty?
+      found ||= have_library(libs.shift)
+    end
+
+    asplode('mysql client') unless found
+
+    [inc, lib]
+  end
+
+  def default_mysql_config_search_path
+    ENV['PATH'].split(File::PATH_SEPARATOR) +
+      DEFAULT_MYSQL_CONFIG_SEARCH_PATHS.map{|dir| "#{dir}/bin" }
+  end
+
+  def mysql_config_glob
+    "{#{default_mysql_config_search_path.join(',')}}/{mysql_config,mysql_config5}"
+  end
+
+  def mysql_config_path
+    @mysql_config_path ||= Dir[mysql_config_glob].first
+  end
+end
+
+class Linux < Unix
+  protected
+
+  def asplode_suggestion
+    'Try `apt-get install libmysqlclient-dev` or `yum install mysql-devel`, '\
+    'check your installation of MySQL and try again.'
+  end
+end
+
+class MacOS < Unix
+  protected
+
+  def asplode_suggestion
+    'Try `brew install mysql`, check your installation of MySQL and try again.'
+  end
+end
+
+class Windows < Platform
+
+end
+
 # 2.0-only
 have_header('ruby/thread.h') && have_func('rb_thread_call_without_gvl', 'ruby/thread.h')
 
@@ -21,63 +165,7 @@ def asplode(lib)
 have_func('rb_hash_dup')
 have_func('rb_intern3')
 
-# borrowed from mysqlplus
-# http://github.com/oldmoe/mysqlplus/blob/master/ext/extconf.rb
-dirs = ENV.fetch('PATH').split(File::PATH_SEPARATOR) + %w(
-  /opt
-  /opt/local
-  /opt/local/mysql
-  /opt/local/lib/mysql5*
-  /usr
-  /usr/mysql
-  /usr/local
-  /usr/local/mysql
-  /usr/local/mysql-*
-  /usr/local/lib/mysql5*
-  /usr/local/opt/mysql5*
-).map { |dir| dir << '/bin' }
-
-GLOB = "{#{dirs.join(',')}}/{mysql_config,mysql_config5,mariadb_config}"
-
-# If the user has provided a --with-mysql-dir argument, we must respect it or fail.
-inc, lib = dir_config('mysql')
-if inc && lib
-  # TODO: Remove when 2.0.0 is the minimum supported version
-  # Ruby versions not incorporating the mkmf fix at
-  # https://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/39717
-  # do not properly search for lib directories, and must be corrected
-  unless lib && lib[-3, 3] == 'lib'
-    @libdir_basename = 'lib'
-    inc, lib = dir_config('mysql')
-  end
-  abort "-----\nCannot find include dir(s) #{inc}\n-----" unless inc && inc.split(File::PATH_SEPARATOR).any? { |dir| File.directory?(dir) }
-  abort "-----\nCannot find library dir(s) #{lib}\n-----" unless lib && lib.split(File::PATH_SEPARATOR).any? { |dir| File.directory?(dir) }
-  warn "-----\nUsing --with-mysql-dir=#{File.dirname inc}\n-----"
-  rpath_dir = lib
-elsif (mc = (with_config('mysql-config') || Dir[GLOB].first))
-  # If the user has provided a --with-mysql-config argument, we must respect it or fail.
-  # If the user gave --with-mysql-config with no argument means we should try to find it.
-  mc = Dir[GLOB].first if mc == true
-  abort "-----\nCannot find mysql_config at #{mc}\n-----" unless mc && File.exist?(mc)
-  abort "-----\nCannot execute mysql_config at #{mc}\n-----" unless File.executable?(mc)
-  warn "-----\nUsing mysql_config at #{mc}\n-----"
-  ver = `#{mc} --version`.chomp.to_f
-  includes = `#{mc} --include`.chomp
-  abort unless $CHILD_STATUS.success?
-  libs = `#{mc} --libs_r`.chomp
-  # MySQL 5.5 and above already have re-entrant code in libmysqlclient (no _r).
-  libs = `#{mc} --libs`.chomp if ver >= 5.5 || libs.empty?
-  abort unless $CHILD_STATUS.success?
-  $INCFLAGS += ' ' + includes
-  $libs = libs + " " + $libs
-  rpath_dir = libs
-else
-  _, usr_local_lib = dir_config('mysql', '/usr/local')
-
-  asplode("mysql client") unless find_library('mysqlclient', 'mysql_query', usr_local_lib, "#{usr_local_lib}/mysql")
-
-  rpath_dir = usr_local_lib
-end
+_, rpath_dir = Platform.current.detect_paths
 
 if have_header('mysql.h')
   prefix = nil
@@ -87,111 +175,92 @@ def asplode(lib)
   asplode 'mysql.h'
 end
 
-%w(errmsg.h mysqld_error.h).each do |h|
-  header = [prefix, h].compact.join '/'
-  asplode h unless have_header header
-end
+  %w{ errmsg.h mysqld_error.h }.each do |h|
+    header = [prefix, h].compact.join '/'
+    asplode h unless have_header h
+  end
 
-# This is our wishlist. We use whichever flags work on the host.
-# -Wall and -Wextra are included by default.
-wishlist = [
-  '-Weverything',
-  '-Wno-bad-function-cast', # rb_thread_call_without_gvl returns void * that we cast to VALUE
-  '-Wno-conditional-uninitialized', # false positive in client.c
-  '-Wno-covered-switch-default', # result.c -- enum_field_types (when fully covered, e.g. mysql 5.5)
-  '-Wno-declaration-after-statement', # GET_CLIENT followed by GET_STATEMENT in statement.c
-  '-Wno-disabled-macro-expansion', # rubby :(
-  '-Wno-documentation-unknown-command', # rubby :(
-  '-Wno-missing-field-initializers', # gperf generates bad code
-  '-Wno-missing-variable-declarations', # missing symbols due to ruby native ext initialization
-  '-Wno-padded', # mysql :(
-  '-Wno-sign-conversion', # gperf generates bad code
-  '-Wno-static-in-inline', # gperf generates bad code
-  '-Wno-switch-enum', # result.c -- enum_field_types (when not fully covered, e.g. mysql 5.6+)
-  '-Wno-undef', # rubinius :(
-  '-Wno-used-but-marked-unused', # rubby :(
-]
-
-if ENV['CI']
-  wishlist += [
-    '-Werror',
-    '-fsanitize=address',
-    '-fsanitize=cfi',
-    '-fsanitize=integer',
-    '-fsanitize=memory',
-    '-fsanitize=thread',
-    '-fsanitize=undefined',
-  ]
-end
+  # This is our wishlist. We use whichever flags work on the host.
+  # -Wall and -Wextra are included by default.
+  # TODO: fix statement.c and remove -Wno-error=declaration-after-statement
+  %w(
+    -Werror
+    -Weverything
+    -fsanitize=address
+    -fsanitize=integer
+    -fsanitize=thread
+    -fsanitize=memory
+    -fsanitize=undefined
+    -fsanitize=cfi
+    -Wno-error=declaration-after-statement
+  ).each do |flag|
+    if try_link('int main() {return 0;}', flag)
+      $CFLAGS << ' ' << flag
+    end
+  end
 
-usable_flags = wishlist.select do |flag|
-  try_link('int main() {return 0;}', flag)
-end
+  if RUBY_PLATFORM =~ /mswin|mingw/
+    # Build libmysql.a interface link library
+    require 'rake'
 
-$CFLAGS << ' ' << usable_flags.join(' ')
-
-if RUBY_PLATFORM =~ /mswin|mingw/
-  # Build libmysql.a interface link library
-  require 'rake'
-
-  # Build libmysql.a interface link library
-  # Use rake to rebuild only if these files change
-  deffile = File.expand_path('../../../support/libmysql.def', __FILE__)
-  libfile = File.expand_path(File.join(rpath_dir, 'libmysql.lib'))
-  file 'libmysql.a' => [deffile, libfile] do
-    when_writing 'building libmysql.a' do
-      # Ruby kindly shows us where dllwrap is, but that tool does more than we want.
-      # Maybe in the future Ruby could provide RbConfig::CONFIG['DLLTOOL'] directly.
-      dlltool = RbConfig::CONFIG['DLLWRAP'].gsub('dllwrap', 'dlltool')
-      sh dlltool, '--kill-at',
-         '--dllname', 'libmysql.dll',
-         '--output-lib', 'libmysql.a',
-         '--input-def', deffile, libfile
+    # Build libmysql.a interface link library
+    # Use rake to rebuild only if these files change
+    deffile = File.expand_path('../../../support/libmysql.def', __FILE__)
+    libfile = File.expand_path(File.join(rpath_dir, 'libmysql.lib'))
+    file 'libmysql.a' => [deffile, libfile] do |t|
+      when_writing 'building libmysql.a' do
+        # Ruby kindly shows us where dllwrap is, but that tool does more than we want.
+        # Maybe in the future Ruby could provide RbConfig::CONFIG['DLLTOOL'] directly.
+        dlltool = RbConfig::CONFIG['DLLWRAP'].gsub('dllwrap', 'dlltool')
+        sh dlltool, '--kill-at',
+          '--dllname', 'libmysql.dll',
+          '--output-lib', 'libmysql.a',
+          '--input-def', deffile, libfile
+      end
     end
-  end
 
-  Rake::Task['libmysql.a'].invoke
-  $LOCAL_LIBS << ' ' << 'libmysql.a'
+    Rake::Task['libmysql.a'].invoke
+    $LOCAL_LIBS << ' ' << 'libmysql.a'
 
-  # Make sure the generated interface library works (if cross-compiling, trust without verifying)
-  unless RbConfig::CONFIG['host_os'] =~ /mswin|mingw/
-    abort "-----\nCannot find libmysql.a\n----" unless have_library('libmysql')
-    abort "-----\nCannot link to libmysql.a (my_init)\n----" unless have_func('my_init')
-  end
+    # Make sure the generated interface library works (if cross-compiling, trust without verifying)
+    unless RbConfig::CONFIG['host_os'] =~ /mswin|mingw/
+      abort "-----\nCannot find libmysql.a\n----" unless have_library('libmysql')
+      abort "-----\nCannot link to libmysql.a (my_init)\n----" unless have_func('my_init')
+    end
 
-  # Vendor libmysql.dll
-  vendordir = File.expand_path('../../../vendor/', __FILE__)
-  directory vendordir
+    # Vendor libmysql.dll
+    vendordir = File.expand_path('../../../vendor/', __FILE__)
+    directory vendordir
 
-  vendordll = File.join(vendordir, 'libmysql.dll')
-  dllfile = File.expand_path(File.join(rpath_dir, 'libmysql.dll'))
-  file vendordll => [dllfile, vendordir] do
-    when_writing 'copying libmysql.dll' do
-      cp dllfile, vendordll
+    vendordll = File.join(vendordir, 'libmysql.dll')
+    dllfile = File.expand_path(File.join(rpath_dir, 'libmysql.dll'))
+    file vendordll => [dllfile, vendordir] do |t|
+      when_writing 'copying libmysql.dll' do
+        cp dllfile, vendordll
+      end
     end
-  end
 
-  # Copy libmysql.dll to the local vendor directory by default
-  if arg_config('--no-vendor-libmysql')
-    # Fine, don't.
-    puts "--no-vendor-libmysql"
-  else # Default: arg_config('--vendor-libmysql')
-    # Let's do it!
-    Rake::Task[vendordll].invoke
-  end
-else
-  case explicit_rpath = with_config('mysql-rpath')
-  when true
-    abort "-----\nOption --with-mysql-rpath must have an argument\n-----"
-  when false
-    warn "-----\nOption --with-mysql-rpath has been disabled at your request\n-----"
-  when String
-    # The user gave us a value so use it
-    rpath_flags = " -Wl,-rpath,#{explicit_rpath}"
-    warn "-----\nSetting mysql rpath to #{explicit_rpath}\n-----"
-    $LDFLAGS << rpath_flags
+    # Copy libmysql.dll to the local vendor directory by default
+    if arg_config('--no-vendor-libmysql')
+      # Fine, don't.
+      puts "--no-vendor-libmysql"
+    else # Default: arg_config('--vendor-libmysql')
+      # Let's do it!
+      Rake::Task[vendordll].invoke
+    end
   else
-    if (libdir = rpath_dir[%r{(-L)?(/[^ ]+)}, 2])
+    case explicit_rpath = with_config('mysql-rpath')
+    when true
+      abort "-----\nOption --with-mysql-rpath must have an argument\n-----"
+    when false
+      warn "-----\nOption --with-mysql-rpath has been disabled at your request\n-----"
+    when String
+      # The user gave us a value so use it
+      rpath_flags = " -Wl,-rpath,#{explicit_rpath}"
+      warn "-----\nSetting mysql rpath to #{explicit_rpath}\n-----"
+      $LDFLAGS << rpath_flags
+    else
+      if libdir = rpath_dir[%r{(-L)?(/[^ ]+)}, 2]
       rpath_flags = " -Wl,-rpath,#{libdir}"
       if RbConfig::CONFIG["RPATHFLAG"].to_s.empty? && try_link('int main() {return 0;}', rpath_flags)
         # Usually Ruby sets RPATHFLAG the right way for each system, but not on OS X.

From 61bcc82ae843cd1338da340b3de061d520870aa9 Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Wed, 1 Apr 2015 18:49:18 +0800
Subject: [PATCH 02/14] Move the header and library and compiler detection to
 the Platform class.

---
 ext/mysql2/extconf.rb | 71 ++++++++++++++++++++++++-------------------
 1 file changed, 39 insertions(+), 32 deletions(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index c03ce985b..846fe88f6 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -14,11 +14,49 @@ def self.current
     end
   end
 
+  def configure
+    detect_paths
+    detect_headers
+    detect_libraries
+
+    configure_compiler
+  end
+
   # @return [(String, String)|nil] The include and library paths.
   def detect_paths
     detect_by_explicit_path || detect_by_mysql_config
   end
 
+  def detect_headers
+    headers = %w{ mysql.h errmsg.h mysqld_error.h }
+    prefix = ['', 'mysql/'].find do |prefix|
+      have_header("#{prefix}mysql.h")
+    end
+
+    headers.each do |header|
+      header = [prefix, h].compact.join '/'
+      asplode(header) unless have_header(header)
+    end
+  end
+
+  def detect_libraries
+    libraries = %w{ mysqlclient libmysql }
+    library = libraries.find do |library|
+      have_library(library, 'mysql_query')
+    end
+
+    asplode 'mysqlclient or libmysql' unless library
+  end
+
+  def configure_compiler
+    # These gcc style flags are also supported by clang and xcode compilers,
+    # so we'll use a does-it-work test instead of an is-it-gcc test.
+    gcc_flags = ' -Wall -funroll-loops'
+    if try_link('int main() {return 0;}', gcc_flags)
+      $CFLAGS << gcc_flags
+    end
+  end
+
   protected
 
   def detect_by_explicit_path
@@ -166,38 +204,7 @@ class Windows < Platform
 have_func('rb_intern3')
 
 _, rpath_dir = Platform.current.detect_paths
-
-if have_header('mysql.h')
-  prefix = nil
-elsif have_header('mysql/mysql.h')
-  prefix = 'mysql'
-else
-  asplode 'mysql.h'
-end
-
-  %w{ errmsg.h mysqld_error.h }.each do |h|
-    header = [prefix, h].compact.join '/'
-    asplode h unless have_header h
-  end
-
-  # This is our wishlist. We use whichever flags work on the host.
-  # -Wall and -Wextra are included by default.
-  # TODO: fix statement.c and remove -Wno-error=declaration-after-statement
-  %w(
-    -Werror
-    -Weverything
-    -fsanitize=address
-    -fsanitize=integer
-    -fsanitize=thread
-    -fsanitize=memory
-    -fsanitize=undefined
-    -fsanitize=cfi
-    -Wno-error=declaration-after-statement
-  ).each do |flag|
-    if try_link('int main() {return 0;}', flag)
-      $CFLAGS << ' ' << flag
-    end
-  end
+Platform.current.configure
 
   if RUBY_PLATFORM =~ /mswin|mingw/
     # Build libmysql.a interface link library

From ad1641c7b95ad47c57cef15fb65d6206fee7b245 Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Wed, 1 Apr 2015 19:07:41 +0800
Subject: [PATCH 03/14] Split the logic for configuring the include and library
 paths by platform.

---
 ext/mysql2/extconf.rb | 155 +++++++++++++++++++++++-------------------
 1 file changed, 84 insertions(+), 71 deletions(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index 846fe88f6..15212c685 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -5,8 +5,10 @@ class Platform
   # Gets the proper platform object for the current platform.
   def self.current
     case RUBY_PLATFORM
-      when /mswin|mingw/
+      when /mswin/
         Windows.new
+      when /mingw/
+        WindowsMingw.new
       when /darwin/
         MacOS.new
       else
@@ -15,13 +17,19 @@ def self.current
   end
 
   def configure
-    detect_paths
+    _, @rpath_dir = detect_paths
     detect_headers
     detect_libraries
 
     configure_compiler
   end
 
+  protected
+
+  def rpath_dir
+    @rpath_dir
+  end
+
   # @return [(String, String)|nil] The include and library paths.
   def detect_paths
     detect_by_explicit_path || detect_by_mysql_config
@@ -57,8 +65,6 @@ def configure_compiler
     end
   end
 
-  protected
-
   def detect_by_explicit_path
     # If the user has provided a --with-mysql-dir argument, we must respect it or fail.
     inc, lib = dir_config('mysql')
@@ -139,12 +145,46 @@ class Unix < Platform
     /usr/local/lib/mysql5*
   ].freeze
 
-  def detect_paths
-    super || detect_by_known_paths
+  def configure
+    super
+
+    case explicit_rpath = with_config('mysql-rpath')
+    when true
+      error 'Option --with-mysql-rpath must have an argument'
+    when false
+      error 'Option --with-mysql-rpath has been disabled at your request'
+    when String
+      # The user gave us a value so use it
+      rpath_flags = " -Wl,-rpath,#{explicit_rpath}"
+      warn "Setting mysql rpath to #{explicit_rpath}"
+      $LDFLAGS << rpath_flags
+    else
+      if libdir = rpath_dir[%r{(-L)?(/[^ ]+)}, 2]
+        rpath_flags = " -Wl,-rpath,#{libdir}"
+        if RbConfig::CONFIG['RPATHFLAG'].to_s.empty? && try_link('int main() {return 0;}', rpath_flags)
+          # Usually Ruby sets RPATHFLAG the right way for each system, but not on OS X.
+          warn "Setting rpath to #{libdir}"
+          $LDFLAGS << rpath_flags
+        else
+          if RbConfig::CONFIG['RPATHFLAG'].to_s.empty?
+            # If we got here because try_link failed, warn the user
+            warn 'Don\'t know how to set rpath on your system, if MySQL '\
+              'libraries are not in path mysql2 may not load'
+          end
+          # Make sure that LIBPATH gets set if we didn't explicitly set the rpath.
+          warn "Setting libpath to #{libdir}"
+          $LIBPATH << libdir unless $LIBPATH.include?(libdir)
+        end
+      end
+    end
   end
 
   protected
 
+  def detect_paths
+    super || detect_by_known_paths
+  end
+
   def detect_by_known_paths
     inc, lib = dir_config('mysql', '/usr/local')
     libs = ['m', 'z', 'socket', 'nsl', 'mygcc']
@@ -191,27 +231,38 @@ def asplode_suggestion
 end
 
 class Windows < Platform
+  def configure
+    super
 
-end
+    require 'rake'
 
-# 2.0-only
-have_header('ruby/thread.h') && have_func('rb_thread_call_without_gvl', 'ruby/thread.h')
+    # Vendor libmysql.dll
+    vendordir = File.expand_path('../../../vendor/', __FILE__)
+    directory vendordir
 
-# 1.9-only
-have_func('rb_thread_blocking_region')
-have_func('rb_wait_for_single_fd')
-have_func('rb_hash_dup')
-have_func('rb_intern3')
+    vendordll = File.join(vendordir, 'libmysql.dll')
+    dllfile = File.expand_path(File.join(rpath_dir, 'libmysql.dll'))
+    file vendordll => [dllfile, vendordir] do |t|
+      when_writing 'copying libmysql.dll' do
+        cp dllfile, vendordll
+      end
+    end
 
-_, rpath_dir = Platform.current.detect_paths
-Platform.current.configure
+    # Copy libmysql.dll to the local vendor directory by default
+    if arg_config('--no-vendor-libmysql')
+      # Fine, don't.
+      puts '--no-vendor-libmysql'
+    else # Default: arg_config('--vendor-libmysql')
+      # Let's do it!
+      Rake::Task[vendordll].invoke
+    end
+  end
+end
 
-  if RUBY_PLATFORM =~ /mswin|mingw/
-    # Build libmysql.a interface link library
-    require 'rake'
+class WindowsMingw < Windows
+  def configure
+    super
 
-    # Build libmysql.a interface link library
-    # Use rake to rebuild only if these files change
     deffile = File.expand_path('../../../support/libmysql.def', __FILE__)
     libfile = File.expand_path(File.join(rpath_dir, 'libmysql.lib'))
     file 'libmysql.a' => [deffile, libfile] do |t|
@@ -231,59 +282,21 @@ class Windows < Platform
 
     # Make sure the generated interface library works (if cross-compiling, trust without verifying)
     unless RbConfig::CONFIG['host_os'] =~ /mswin|mingw/
-      abort "-----\nCannot find libmysql.a\n----" unless have_library('libmysql')
-      abort "-----\nCannot link to libmysql.a (my_init)\n----" unless have_func('my_init')
+      error 'Cannot find libmysql.a' unless have_library('libmysql')
+      error 'Cannot link to libmysql.a (my_init)' unless have_func('my_init')
     end
+  end
+end
 
-    # Vendor libmysql.dll
-    vendordir = File.expand_path('../../../vendor/', __FILE__)
-    directory vendordir
+# 2.0-only
+have_header('ruby/thread.h') && have_func('rb_thread_call_without_gvl', 'ruby/thread.h')
 
-    vendordll = File.join(vendordir, 'libmysql.dll')
-    dllfile = File.expand_path(File.join(rpath_dir, 'libmysql.dll'))
-    file vendordll => [dllfile, vendordir] do |t|
-      when_writing 'copying libmysql.dll' do
-        cp dllfile, vendordll
-      end
-    end
+# 1.9-only
+have_func('rb_thread_blocking_region')
+have_func('rb_wait_for_single_fd')
+have_func('rb_hash_dup')
+have_func('rb_intern3')
 
-    # Copy libmysql.dll to the local vendor directory by default
-    if arg_config('--no-vendor-libmysql')
-      # Fine, don't.
-      puts "--no-vendor-libmysql"
-    else # Default: arg_config('--vendor-libmysql')
-      # Let's do it!
-      Rake::Task[vendordll].invoke
-    end
-  else
-    case explicit_rpath = with_config('mysql-rpath')
-    when true
-      abort "-----\nOption --with-mysql-rpath must have an argument\n-----"
-    when false
-      warn "-----\nOption --with-mysql-rpath has been disabled at your request\n-----"
-    when String
-      # The user gave us a value so use it
-      rpath_flags = " -Wl,-rpath,#{explicit_rpath}"
-      warn "-----\nSetting mysql rpath to #{explicit_rpath}\n-----"
-      $LDFLAGS << rpath_flags
-    else
-      if libdir = rpath_dir[%r{(-L)?(/[^ ]+)}, 2]
-      rpath_flags = " -Wl,-rpath,#{libdir}"
-      if RbConfig::CONFIG["RPATHFLAG"].to_s.empty? && try_link('int main() {return 0;}', rpath_flags)
-        # Usually Ruby sets RPATHFLAG the right way for each system, but not on OS X.
-        warn "-----\nSetting rpath to #{libdir}\n-----"
-        $LDFLAGS << rpath_flags
-      else
-        if RbConfig::CONFIG["RPATHFLAG"].to_s.empty?
-          # If we got here because try_link failed, warn the user
-          warn "-----\nDon't know how to set rpath on your system, if MySQL libraries are not in path mysql2 may not load\n-----"
-        end
-        # Make sure that LIBPATH gets set if we didn't explicitly set the rpath.
-        warn "-----\nSetting libpath to #{libdir}\n-----"
-        $LIBPATH << libdir unless $LIBPATH.include?(libdir)
-      end
-    end
-  end
-end
+Platform.current.configure
 
 create_makefile('mysql2/mysql2')

From a0cb29276069cdf68baee288c87043e7eb7ba79f Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Wed, 1 Apr 2015 19:11:26 +0800
Subject: [PATCH 04/14] Skip mysql-config if we cannot detect it.

---
 ext/mysql2/extconf.rb | 34 ++++++++++++++++++----------------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index 15212c685..aa68c7410 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -87,25 +87,27 @@ def detect_by_explicit_path
   end
 
   def detect_by_mysql_config
-    if with_config('mysql-config') && !mysql_config_path
-      error 'Cannot find mysql_config'
-    end
-    warn  "Using mysql_config at #{mysql_config_path}"
+    if mysql_config_path
+      warn  "Using mysql_config at #{mysql_config_path}"
 
-    ver = `#{mysql_config_path} --version`.chomp.to_f
-    includes = `#{mysql_config_path} --include`.chomp
-    exit 1 if $? != 0
-    libs = `#{mysql_config_path} --libs_r`.chomp
+      ver = `#{mysql_config_path} --version`.chomp.to_f
+      includes = `#{mysql_config_path} --include`.chomp
+      exit 1 if $? != 0
+      libs = `#{mysql_config_path} --libs_r`.chomp
 
-    # MySQL 5.5 and above already have re-entrant code in libmysqlclient (no _r).
-    if ver >= 5.5 || libs.empty?
-      libs = `#{mysql_config_path} --libs`.chomp
-    end
-    exit 1 if $? != 0
+      # MySQL 5.5 and above already have re-entrant code in libmysqlclient (no _r).
+      if ver >= 5.5 || libs.empty?
+        libs = `#{mysql_config_path} --libs`.chomp
+      end
+      exit 1 if $? != 0
 
-    $INCFLAGS += ' ' + includes
-    $libs = "#{libs} #{$libs}"
-    [includes, libs]
+      $INCFLAGS += ' ' + includes
+      $libs = "#{libs} #{$libs}"
+      [includes, libs]
+    else
+      error 'Cannot find mysql_config' if with_config('mysql-config')
+      nil
+    end
   end
 
   def error(message)

From f93d3519eb5e2733b0b443124d8bb32113302f8e Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Wed, 1 Apr 2015 19:14:18 +0800
Subject: [PATCH 05/14] We provide the directory separator in our prefixes.

---
 ext/mysql2/extconf.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index aa68c7410..04b852257 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -42,7 +42,7 @@ def detect_headers
     end
 
     headers.each do |header|
-      header = [prefix, h].compact.join '/'
+      header = "#{prefix}#{header}"
       asplode(header) unless have_header(header)
     end
   end
@@ -119,7 +119,7 @@ def warn(message)
   end
 
   def asplode(library)
-    complain("#{library} is missing. #{asplode_suggestion}")
+    error("#{library} is missing. #{asplode_suggestion}")
   end
 
   def asplode_suggestion

From 6fdb088200dd8fa063e58738ae026b7589f7b93a Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Wed, 1 Apr 2015 19:36:52 +0800
Subject: [PATCH 06/14] Don't double check mysql.h

---
 ext/mysql2/extconf.rb | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index 04b852257..ac04017ed 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -36,10 +36,11 @@ def detect_paths
   end
 
   def detect_headers
-    headers = %w{ mysql.h errmsg.h mysqld_error.h }
+    headers = %w{ errmsg.h mysqld_error.h }
     prefix = ['', 'mysql/'].find do |prefix|
       have_header("#{prefix}mysql.h")
     end
+    asplode('mysql.h') unless prefix
 
     headers.each do |header|
       header = "#{prefix}#{header}"

From 13d8fbbea404589c92ea51e4503d58d48e95e326 Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Wed, 1 Apr 2015 19:37:33 +0800
Subject: [PATCH 07/14] Allow users to succeed building the extension even when
 libmysql.dll cannot be found.

---
 ext/mysql2/extconf.rb | 40 ++++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index ac04017ed..f54fe99a9 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -1,6 +1,13 @@
 # encoding: UTF-8
 require 'mkmf'
 
+# For compatibility with Ruby 1.8 and Ruby EE, whose Rake breaks Object#rm_f
+class << self
+   alias_method :rm_f_original, :rm_f
+   require 'rake'
+   alias_method :rm_f, :rm_f_original
+end
+
 class Platform
   # Gets the proper platform object for the current platform.
   def self.current
@@ -234,29 +241,30 @@ def asplode_suggestion
 end
 
 class Windows < Platform
+  include Rake::DSL
+
   def configure
     super
 
-    require 'rake'
-
-    # Vendor libmysql.dll
-    vendordir = File.expand_path('../../../vendor/', __FILE__)
-    directory vendordir
-
-    vendordll = File.join(vendordir, 'libmysql.dll')
-    dllfile = File.expand_path(File.join(rpath_dir, 'libmysql.dll'))
-    file vendordll => [dllfile, vendordir] do |t|
-      when_writing 'copying libmysql.dll' do
-        cp dllfile, vendordll
-      end
-    end
-
     # Copy libmysql.dll to the local vendor directory by default
     if arg_config('--no-vendor-libmysql')
       # Fine, don't.
-      puts '--no-vendor-libmysql'
+      warn 'Not including local libmysql.dll'
+    elsif !rpath_dir
+      error 'Cannot deduce path to libmysql.dll'
     else # Default: arg_config('--vendor-libmysql')
-      # Let's do it!
+      # Vendor libmysql.dll
+      vendordir = File.expand_path('../../../vendor/', __FILE__)
+      directory vendordir
+
+      vendordll = File.join(vendordir, 'libmysql.dll')
+      dllfile = File.expand_path(File.join(rpath_dir, 'libmysql.dll'))
+      file vendordll => [dllfile, vendordir] do |t|
+        when_writing 'copying libmysql.dll' do
+          cp dllfile, vendordll
+        end
+      end
+
       Rake::Task[vendordll].invoke
     end
   end

From 078d93b854767c9d0d6ea2698ca0393e38776eeb Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Sat, 6 Jun 2015 11:46:20 +0800
Subject: [PATCH 08/14] Default to the mysql-config path specified on the
 command line.

---
 ext/mysql2/extconf.rb | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index f54fe99a9..65b7fc254 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -135,7 +135,7 @@ def asplode_suggestion
   end
 
   def mysql_config_path
-    nil
+    @mysql_config_path ||= with_config('mysql-config')
   end
 end
 
@@ -219,6 +219,7 @@ def mysql_config_glob
   end
 
   def mysql_config_path
+    super
     @mysql_config_path ||= Dir[mysql_config_glob].first
   end
 end

From bcb46bf839ddb99535b4fc978aa17e4ac7825fd4 Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Thu, 11 Jun 2015 07:50:28 +0800
Subject: [PATCH 09/14] Check for supported compiler flags.

---
 ext/mysql2/extconf.rb | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index 65b7fc254..c08aa7d55 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -65,11 +65,20 @@ def detect_libraries
   end
 
   def configure_compiler
-    # These gcc style flags are also supported by clang and xcode compilers,
-    # so we'll use a does-it-work test instead of an is-it-gcc test.
-    gcc_flags = ' -Wall -funroll-loops'
-    if try_link('int main() {return 0;}', gcc_flags)
-      $CFLAGS << gcc_flags
+    # This is our wishlist. We use whichever flags work on the host.
+    # TODO: fix statement.c and remove -Wno-declaration-after-statement
+    # TODO: fix gperf mysql_enc_name_to_ruby.h and remove -Wno-missing-field-initializers
+    %w(
+      -Wall
+      -Wextra
+      -Werror
+      -Wno-unused-function
+      -Wno-declaration-after-statement
+      -Wno-missing-field-initializers
+    ).select do |flag|
+      try_link('int main() {return 0;}', flag)
+    end.each do |flag|
+      $CFLAGS << ' ' << flag
     end
   end
 

From 4d67f57d1162da3eb2c9da4462281b9c312528b5 Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Thu, 11 Jun 2015 07:50:56 +0800
Subject: [PATCH 10/14] Check for mariadb's configuration as well.

---
 ext/mysql2/extconf.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index c08aa7d55..415ce1be6 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -224,7 +224,7 @@ def default_mysql_config_search_path
   end
 
   def mysql_config_glob
-    "{#{default_mysql_config_search_path.join(',')}}/{mysql_config,mysql_config5}"
+    "{#{default_mysql_config_search_path.join(',')}}/{mysql_config,mysql_config5,mariadb_config}"
   end
 
   def mysql_config_path

From f2fe877c47affebec73dc0682625491f3766ec88 Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Thu, 11 Jun 2015 09:00:36 +0800
Subject: [PATCH 11/14] Support more paths where mysql might be installed.

---
 ext/mysql2/extconf.rb | 1 +
 1 file changed, 1 insertion(+)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index 415ce1be6..f31a3c55f 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -162,6 +162,7 @@ class Unix < Platform
     /usr/local/mysql
     /usr/local/mysql-*
     /usr/local/lib/mysql5*
+    /usr/local/opt/mysql5*
   ].freeze
 
   def configure

From 46367f68a4f4ab2286cd0df22ed723267d2a0a7e Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Thu, 11 Jun 2015 09:05:34 +0800
Subject: [PATCH 12/14] Do not get into an infinite loop if all the extra
 libraries have been exhausted and a mysql library cannot be found.

---
 ext/mysql2/extconf.rb | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index f31a3c55f..eb60bd6b6 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -207,14 +207,7 @@ def detect_paths
 
   def detect_by_known_paths
     inc, lib = dir_config('mysql', '/usr/local')
-    libs = ['m', 'z', 'socket', 'nsl', 'mygcc']
-    found = false
-    until find_library('mysqlclient', 'mysql_query', lib, "#{lib}/mysql") do
-      break if libs.empty?
-      found ||= have_library(libs.shift)
-    end
-
-    asplode('mysql client') unless found
+    asplode('mysql client') unless has_mysql_client?(lib)
 
     [inc, lib]
   end
@@ -232,6 +225,12 @@ def mysql_config_path
     super
     @mysql_config_path ||= Dir[mysql_config_glob].first
   end
+
+  private
+
+  def has_mysql_client?(lib)
+    find_library('mysqlclient', 'mysql_query', lib, "#{lib}/mysql")
+  end
 end
 
 class Linux < Unix

From b5c1f9b99adc590c8f68b0fbafde16e6eb051a62 Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Wed, 30 Sep 2015 14:49:56 +0800
Subject: [PATCH 13/14] Cherry-pick changes from new commits.

 - 83d36e24d260acd13f0071db9b0bef071ecb5684
 - 110d05c706c28f4495716fda5e937d0a49d04b7d
 - 5b1d0952b5c42a320203961f9d76470415557cca
 - a253352b26f07d9926bfd35aada5e8cec73aeb33
 - 0f56af3e619626716078a56e97479c383e47f3dd
 - 8f9eec4183d796246648c72f64578ae55829a409
 - c5b8a1698d209982711e669a63ec3f833f73e58a
 - 6c64816c848a20026656e0e6b55defafa85fcb15
 - a98b7bbfa594730e1c53c0a0591b0fada494fafa
---
 ext/mysql2/extconf.rb | 67 +++++++++++++++++++++++++++++--------------
 1 file changed, 45 insertions(+), 22 deletions(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index eb60bd6b6..6c7217f98 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -1,5 +1,6 @@
 # encoding: UTF-8
 require 'mkmf'
+require 'English'
 
 # For compatibility with Ruby 1.8 and Ruby EE, whose Rake breaks Object#rm_f
 class << self
@@ -68,24 +69,48 @@ def configure_compiler
     # This is our wishlist. We use whichever flags work on the host.
     # TODO: fix statement.c and remove -Wno-declaration-after-statement
     # TODO: fix gperf mysql_enc_name_to_ruby.h and remove -Wno-missing-field-initializers
-    %w(
-      -Wall
-      -Wextra
-      -Werror
-      -Wno-unused-function
-      -Wno-declaration-after-statement
-      -Wno-missing-field-initializers
-    ).select do |flag|
+    wishlist = [
+      '-Weverything',
+      '-Wno-bad-function-cast', # rb_thread_call_without_gvl returns void * that we cast to VALUE
+      '-Wno-conditional-uninitialized', # false positive in client.c
+      '-Wno-covered-switch-default', # result.c -- enum_field_types (when fully covered, e.g. mysql 5.5)
+      '-Wno-declaration-after-statement', # GET_CLIENT followed by GET_STATEMENT in statement.c
+      '-Wno-disabled-macro-expansion', # rubby :(
+      '-Wno-documentation-unknown-command', # rubby :(
+      '-Wno-missing-field-initializers', # gperf generates bad code
+      '-Wno-missing-variable-declarations', # missing symbols due to ruby native ext initialization
+      '-Wno-padded', # mysql :(
+      '-Wno-sign-conversion', # gperf generates bad code
+      '-Wno-static-in-inline', # gperf generates bad code
+      '-Wno-switch-enum', # result.c -- enum_field_types (when not fully covered, e.g. mysql 5.6+)
+      '-Wno-undef', # rubinius :(
+      '-Wno-used-but-marked-unused', # rubby :(
+    ]
+
+    if ENV['CI']
+      wishlist += [
+        '-Werror',
+        '-fsanitize=address',
+        '-fsanitize=cfi',
+        '-fsanitize=integer',
+        '-fsanitize=memory',
+        '-fsanitize=thread',
+        '-fsanitize=undefined',
+      ]
+    end
+
+    usable_flags = wishlist.select do |flag|
       try_link('int main() {return 0;}', flag)
-    end.each do |flag|
-      $CFLAGS << ' ' << flag
     end
+
+    $CFLAGS << ' ' << usable_flags.join(' ')
   end
 
   def detect_by_explicit_path
     # If the user has provided a --with-mysql-dir argument, we must respect it or fail.
     inc, lib = dir_config('mysql')
     if inc && lib
+      # TODO: Remove when 2.0.0 is the minimum supported version
       # Ruby versions not incorporating the mkmf fix at
       # https://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/39717
       # do not properly search for lib directories, and must be corrected
@@ -96,7 +121,7 @@ def detect_by_explicit_path
 
       error "Cannot find include dir(s) #{inc}" unless inc && inc.split(File::PATH_SEPARATOR).any?{|dir| File.directory?(dir)}
       error "Cannot find library dir(s) #{lib}" unless lib && lib.split(File::PATH_SEPARATOR).any?{|dir| File.directory?(dir)}
-      warn  "Using --with-mysql-dir=#{File.dirname(inc)}"
+      warn "Using --with-mysql-dir=#{File.dirname(inc)}"
       [inc, lib]
     else
       nil
@@ -109,14 +134,12 @@ def detect_by_mysql_config
 
       ver = `#{mysql_config_path} --version`.chomp.to_f
       includes = `#{mysql_config_path} --include`.chomp
-      exit 1 if $? != 0
+      abort unless $CHILD_STATUS.success?
       libs = `#{mysql_config_path} --libs_r`.chomp
 
       # MySQL 5.5 and above already have re-entrant code in libmysqlclient (no _r).
-      if ver >= 5.5 || libs.empty?
-        libs = `#{mysql_config_path} --libs`.chomp
-      end
-      exit 1 if $? != 0
+      libs = `#{mysql_config_path} --libs`.chomp if ver >= 5.5 || libs.empty?
+      abort unless $CHILD_STATUS.success?
 
       $INCFLAGS += ' ' + includes
       $libs = "#{libs} #{$libs}"
@@ -140,7 +163,7 @@ def asplode(library)
   end
 
   def asplode_suggestion
-    'Please check your installation of MySQL and try again.'
+    'Check your installation of MySQL or Connector/C and try again.'
   end
 
   def mysql_config_path
@@ -213,8 +236,8 @@ def detect_by_known_paths
   end
 
   def default_mysql_config_search_path
-    ENV['PATH'].split(File::PATH_SEPARATOR) +
-      DEFAULT_MYSQL_CONFIG_SEARCH_PATHS.map{|dir| "#{dir}/bin" }
+    ENV.fetch('PATH').split(File::PATH_SEPARATOR) +
+      DEFAULT_MYSQL_CONFIG_SEARCH_PATHS.map {|dir| "#{dir}/bin" }
   end
 
   def mysql_config_glob
@@ -237,8 +260,8 @@ class Linux < Unix
   protected
 
   def asplode_suggestion
-    'Try `apt-get install libmysqlclient-dev` or `yum install mysql-devel`, '\
-    'check your installation of MySQL and try again.'
+    "You may need to 'apt-get install libmysqlclient-dev' or 'yum install mysql-devel', and try "\
+    "again."
   end
 end
 
@@ -246,7 +269,7 @@ class MacOS < Unix
   protected
 
   def asplode_suggestion
-    'Try `brew install mysql`, check your installation of MySQL and try again.'
+    "You may need to 'brew install mysql' or 'port install mysql', and try again."
   end
 end
 

From 80c4eec832e8de242e41886214eef3da98dc6402 Mon Sep 17 00:00:00 2001
From: Joel Low <joel@joelsplace.sg>
Date: Wed, 30 Sep 2015 14:54:32 +0800
Subject: [PATCH 14/14] Fix Rubocop warnings.

---
 ext/mysql2/extconf.rb | 73 +++++++++++++++++++++++--------------------
 1 file changed, 39 insertions(+), 34 deletions(-)

diff --git a/ext/mysql2/extconf.rb b/ext/mysql2/extconf.rb
index 6c7217f98..0602171b1 100644
--- a/ext/mysql2/extconf.rb
+++ b/ext/mysql2/extconf.rb
@@ -2,6 +2,9 @@
 require 'mkmf'
 require 'English'
 
+# Disable these cops, because they make the build script _harder_ to read.
+# rubocop:disable Metrics/ClassLength, Style/GuardClause
+
 # For compatibility with Ruby 1.8 and Ruby EE, whose Rake breaks Object#rm_f
 class << self
    alias_method :rm_f_original, :rm_f
@@ -9,18 +12,21 @@ class << self
    alias_method :rm_f, :rm_f_original
 end
 
+# Represents the base configuration for all platforms.
 class Platform
+  attr_accessor :rpath_dir
+
   # Gets the proper platform object for the current platform.
   def self.current
     case RUBY_PLATFORM
-      when /mswin/
-        Windows.new
-      when /mingw/
-        WindowsMingw.new
-      when /darwin/
-        MacOS.new
-      else
-        Linux.new
+    when /mswin/
+      Windows.new
+    when /mingw/
+      WindowsMingw.new
+    when /darwin/
+      MacOS.new
+    else
+      Linux.new
     end
   end
 
@@ -34,19 +40,15 @@ def configure
 
   protected
 
-  def rpath_dir
-    @rpath_dir
-  end
-
   # @return [(String, String)|nil] The include and library paths.
   def detect_paths
     detect_by_explicit_path || detect_by_mysql_config
   end
 
   def detect_headers
-    headers = %w{ errmsg.h mysqld_error.h }
-    prefix = ['', 'mysql/'].find do |prefix|
-      have_header("#{prefix}mysql.h")
+    headers = %w(errmsg.h mysqld_error.h)
+    prefix = ['', 'mysql/'].find do |candidate|
+      have_header("#{candidate}mysql.h")
     end
     asplode('mysql.h') unless prefix
 
@@ -57,9 +59,9 @@ def detect_headers
   end
 
   def detect_libraries
-    libraries = %w{ mysqlclient libmysql }
-    library = libraries.find do |library|
-      have_library(library, 'mysql_query')
+    libraries = %w(mysqlclient libmysql)
+    library = libraries.find do |candidate|
+      have_library(candidate, 'mysql_query')
     end
 
     asplode 'mysqlclient or libmysql' unless library
@@ -119,18 +121,16 @@ def detect_by_explicit_path
         inc, lib = dir_config('mysql')
       end
 
-      error "Cannot find include dir(s) #{inc}" unless inc && inc.split(File::PATH_SEPARATOR).any?{|dir| File.directory?(dir)}
-      error "Cannot find library dir(s) #{lib}" unless lib && lib.split(File::PATH_SEPARATOR).any?{|dir| File.directory?(dir)}
+      error "Cannot find include dir(s) #{inc}" unless inc && inc.split(File::PATH_SEPARATOR).any? { |dir| File.directory?(dir) }
+      error "Cannot find library dir(s) #{lib}" unless lib && lib.split(File::PATH_SEPARATOR).any? { |dir| File.directory?(dir) }
       warn "Using --with-mysql-dir=#{File.dirname(inc)}"
       [inc, lib]
-    else
-      nil
     end
   end
 
   def detect_by_mysql_config
     if mysql_config_path
-      warn  "Using mysql_config at #{mysql_config_path}"
+      warn "Using mysql_config at #{mysql_config_path}"
 
       ver = `#{mysql_config_path} --version`.chomp.to_f
       includes = `#{mysql_config_path} --include`.chomp
@@ -171,10 +171,11 @@ def mysql_config_path
   end
 end
 
+# Configuration for generic Unix
 class Unix < Platform
   # borrowed from mysqlplus
   # http://github.com/oldmoe/mysqlplus/blob/master/ext/extconf.rb
-  DEFAULT_MYSQL_CONFIG_SEARCH_PATHS = %w[
+  DEFAULT_MYSQL_CONFIG_SEARCH_PATHS = %w(
     /opt
     /opt/local
     /opt/local/mysql
@@ -186,7 +187,7 @@ class Unix < Platform
     /usr/local/mysql-*
     /usr/local/lib/mysql5*
     /usr/local/opt/mysql5*
-  ].freeze
+  ).freeze
 
   def configure
     super
@@ -202,7 +203,7 @@ def configure
       warn "Setting mysql rpath to #{explicit_rpath}"
       $LDFLAGS << rpath_flags
     else
-      if libdir = rpath_dir[%r{(-L)?(/[^ ]+)}, 2]
+      if (libdir = rpath_dir[%r{(-L)?(/[^ ]+)}, 2])
         rpath_flags = " -Wl,-rpath,#{libdir}"
         if RbConfig::CONFIG['RPATHFLAG'].to_s.empty? && try_link('int main() {return 0;}', rpath_flags)
           # Usually Ruby sets RPATHFLAG the right way for each system, but not on OS X.
@@ -230,14 +231,14 @@ def detect_paths
 
   def detect_by_known_paths
     inc, lib = dir_config('mysql', '/usr/local')
-    asplode('mysql client') unless has_mysql_client?(lib)
+    asplode('mysql client') unless mysql_client?(lib)
 
     [inc, lib]
   end
 
   def default_mysql_config_search_path
     ENV.fetch('PATH').split(File::PATH_SEPARATOR) +
-      DEFAULT_MYSQL_CONFIG_SEARCH_PATHS.map {|dir| "#{dir}/bin" }
+      DEFAULT_MYSQL_CONFIG_SEARCH_PATHS.map { |dir| "#{dir}/bin" }
   end
 
   def mysql_config_glob
@@ -251,11 +252,12 @@ def mysql_config_path
 
   private
 
-  def has_mysql_client?(lib)
+  def mysql_client?(lib)
     find_library('mysqlclient', 'mysql_query', lib, "#{lib}/mysql")
   end
 end
 
+# Configuration for Linux
 class Linux < Unix
   protected
 
@@ -265,6 +267,7 @@ def asplode_suggestion
   end
 end
 
+# Configuration for Mac OS
 class MacOS < Unix
   protected
 
@@ -273,6 +276,7 @@ def asplode_suggestion
   end
 end
 
+# Configuration for Windows
 class Windows < Platform
   include Rake::DSL
 
@@ -292,7 +296,7 @@ def configure
 
       vendordll = File.join(vendordir, 'libmysql.dll')
       dllfile = File.expand_path(File.join(rpath_dir, 'libmysql.dll'))
-      file vendordll => [dllfile, vendordir] do |t|
+      file vendordll => [dllfile, vendordir] do
         when_writing 'copying libmysql.dll' do
           cp dllfile, vendordll
         end
@@ -303,21 +307,22 @@ def configure
   end
 end
 
+# Configuration for MingW builds on Windows
 class WindowsMingw < Windows
   def configure
     super
 
     deffile = File.expand_path('../../../support/libmysql.def', __FILE__)
     libfile = File.expand_path(File.join(rpath_dir, 'libmysql.lib'))
-    file 'libmysql.a' => [deffile, libfile] do |t|
+    file 'libmysql.a' => [deffile, libfile] do
       when_writing 'building libmysql.a' do
         # Ruby kindly shows us where dllwrap is, but that tool does more than we want.
         # Maybe in the future Ruby could provide RbConfig::CONFIG['DLLTOOL'] directly.
         dlltool = RbConfig::CONFIG['DLLWRAP'].gsub('dllwrap', 'dlltool')
         sh dlltool, '--kill-at',
-          '--dllname', 'libmysql.dll',
-          '--output-lib', 'libmysql.a',
-          '--input-def', deffile, libfile
+           '--dllname', 'libmysql.dll',
+           '--output-lib', 'libmysql.a',
+           '--input-def', deffile, libfile
       end
     end