Merge pull request #704 from sodabrew/with_sanitize_gcc

Update --with-sanitize for compatibility with GCC Address Sanitizer too

Author: sodabrew

.travis.yml

@@ -40,9 +40,6 @@ matrix:
            - mysql2gem.example.com
     - rvm: 2.0.0
       env: DB=mysql57
-    - rvm: 2.0.0
-      env: DB=mysql
-      os: osx
     - rvm: 2.0.0
       env: DB=mysql55
       os: osx

README.md

@@ -64,6 +64,13 @@ 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.
+To see line numbers in backtraces, declare these environment variables
+(adjust the llvm-symbolizer path as needed for your system):
+
+``` sh
+  export ASAN_SYMBOLIZER_PATH=/usr/bin/llvm-symbolizer-3.4
+  export ASAN_OPTIONS=symbolize=1
+```
 
 ### Linux and other Unixes
 

ext/mysql2/extconf.rb

@@ -115,7 +115,7 @@ def asplode(lib)
 ]
 
 usable_flags = wishlist.select do |flag|
-  try_link('int main() {return 0;}',  "-Werror -Wunknown-warning-option #{flag}")
+  try_link('int main() {return 0;}',  "-Werror #{flag}")
 end
 
 $CFLAGS << ' ' << usable_flags.join(' ')
@@ -127,12 +127,13 @@ def asplode(lib)
 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}")
+    try_link('int main() {return 0;}',  "-Werror -fsanitize=#{s}")
   end
+  abort "-----\nCould not enable any sanitizers!\n-----" if enabled_sanitizers.empty?
 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}")
+    try_link('int main() {return 0;}',  "-Werror -fsanitize=#{s}")
   end
 end
 
@@ -149,6 +150,8 @@ def asplode(lib)
     end
     $CFLAGS << " -fsanitize=#{s}"
   end
+  # Options for line numbers in backtraces
+  $CFLAGS << ' -g -fno-omit-frame-pointer'
 end
 
 if RUBY_PLATFORM =~ /mswin|mingw/