build: disable debug and sanitizers by default (#251)

Debug builds should never be the default. Change debug option to
default to off and link it to sanitizer usage (rather than whether
being built from git tree). Address sanitizers can cause a program
to run twice as slow on top of the debug "-O0" non-optimisation.
Also remove some unused macro variables.

build.sh

@@ -1,12 +1,12 @@
 #!/bin/sh -x
 
-configureOpts="--disable-sanitizers --disable-debug"
+configureOpts=""
 
 while getopts ":hd" opt; do
   case ${opt} in
     h ) echo "Use -d to turn on sanitizers (for debugging only)"
       exit;;
-    d ) configureOpts=""
+    d ) configureOpts="--enable-debug"
       ;;
     \? ) echo "Usage: $0 [-h] [-d]"
       exit;;

configure.ac

@@ -48,7 +48,7 @@ AX_CODE_COVERAGE
 
 dnl is_release must be lowercase because AX_CHECK_ENABLE_DEBUG calls m4_tolower
 dnl on its fourth argument.
-AX_CHECK_ENABLE_DEBUG([yes], , [UNUSED_NDEBUG], [$is_release])
+AX_CHECK_ENABLE_DEBUG([no], , , [$is_release])
 
 AC_PROG_CC
 
@@ -132,14 +132,14 @@ AC_CHECK_HEADERS([fcntl.h float.h inttypes.h limits.h locale.h netinet/in.h path
 
 AC_CONFIG_FILES([Makefile])
 
-# Enable address sanitizer for non-release builds. The performance hit is a
+# Enable address sanitizer for debug builds. The performance hit is a
 # 50% increase of wallclock time for the testsuite on my machine.
-if test x$is_release = xyes; then
-	default_sanitizers=
-else
+if test "x$ax_enable_debug" = "xyes"; then
 	default_sanitizers=address
+else
+	default_sanitizers=
 fi
-AX_SANITIZERS(, [$default_sanitizers], [AC_DEFINE([I3LOCK_ASAN_ENABLED], [], [Enable ASAN])])
+AX_SANITIZERS(, [$default_sanitizers])
 
 AC_OUTPUT