Add new option --with-sanitize[=list,of,clang,sanitizers]

Author: sodabrew

README.md

@@ -58,6 +58,13 @@ This may be needed if you deploy to a system where these libraries
 are located somewhere different than on your build system.
 This overrides any rpath calculated by default or by the options above.
 
+* `--with-sanitize[=address,cfi,integer,memory,thread,undefined]` -
+Enable sanitizers for Clang / GCC. If no argument is given, try to enable
+all sanitizers or fail if none are available. If a command-separated list of
+specific sanitizers is given, configure will fail unless they all are available.
+Note that the some sanitizers may incur a performance penalty, and the Address
+Sanitizer may require a runtime library.
+
 ### Linux and other Unixes
 
 You may need to install a package such as `libmysqlclient-dev` or `mysql-devel`;

ext/mysql2/extconf.rb

@@ -105,31 +105,52 @@ def asplode(lib)
   '-Wno-missing-field-initializers', # gperf generates bad code
   '-Wno-missing-variable-declarations', # missing symbols due to ruby native ext initialization
   '-Wno-padded', # mysql :(
+  '-Wno-reserved-id-macro', # rubby :(
   '-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-unreachable-code', # rubby :(
   '-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)
+  try_link('int main() {return 0;}',  "-Werror -Wunknown-warning-option #{flag}")
 end
 
 $CFLAGS << ' ' << usable_flags.join(' ')
 
+enabled_sanitizers = disabled_sanitizers = []
+# Specify a commna-separated list of sanitizers, or try them all by default
+sanitizers = with_config('sanitize')
+case sanitizers
+when true
+  # Try them all, turn on whatever we can
+  enabled_sanitizers = %w(address cfi integer memory thread undefined).select do |s|
+    try_link('int main() {return 0;}',  "-Werror -Wunknown-warning-option -fsanitize=#{s}")
+  end
+when String
+  # Figure out which sanitizers are supported
+  enabled_sanitizers, disabled_sanitizers = sanitizers.split(',').partition do |s|
+    try_link('int main() {return 0;}',  "-Werror -Wunknown-warning-option -fsanitize=#{s}")
+  end
+end
+
+unless disabled_sanitizers.empty?
+  abort "-----\nCould not enable requested sanitizers: #{disabled_sanitizers.join(',')}\n-----"
+end
+
+unless enabled_sanitizers.empty?
+  warn "-----\nEnabling sanitizers: #{enabled_sanitizers.join(',')}\n-----"
+  enabled_sanitizers.each do |s|
+    # address sanitizer requires runtime support
+    if s == 'address' # rubocop:disable Style/IfUnlessModifier
+      have_library('asan') || $LDFLAGS << ' -fsanitize=address'
+    end
+    $CFLAGS << " -fsanitize=#{s}"
+  end
+end
+
 if RUBY_PLATFORM =~ /mswin|mingw/
   # Build libmysql.a interface link library
   require 'rake'
@@ -155,8 +176,8 @@ def asplode(lib)
 
   # 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')
+    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