Disallow building in the source directory (because of generated files)

configure.ac

@@ -5,12 +5,20 @@ AC_CONFIG_MACRO_DIRS([config/m4])
 AC_LANG(C)
 AC_PREFIX_DEFAULT(/usr/local)
 
+##########
+# CHECKS #
+##########
+
 AC_PATH_PROG([XXD],[xxd],[:])
 AC_PATH_PROG([MAN],[man],[:])
 AS_IF([test "$XXD" = "notfound"], [AC_MSG_ERROR([xxd is required])])
 AS_IF([test "$MAN" = "notfound"], [AC_MSG_ERROR([man is required])])
 
-# Checks
+LKT_PATH_SOURCE="$(dirname $(readlink -f "$0"))"
+LKT_PATH_BUILD="$(pwd)"
+AS_IF([test "$LKT_PATH_SOURCE" = "$LKT_PATH_BUILD"],
+      [AC_MSG_ERROR([The build directory can't be the same as the source directory])])
+
 AC_CHECK_LIB([sqlite3], [sqlite3_open_v2])
 AC_CHECK_HEADERS_ONCE([
     sqlite3.h
@@ -29,12 +37,6 @@ AC_CHECK_HEADERS_ONCE([
     regex.h
     locale.h
     assert.h
-    regex
-    stdexcept
-    vector
-    string
-    locale
-    type_traits
 ])
 
 AC_C_INLINE
@@ -51,7 +53,9 @@ AC_TYPE_UINT32_T
 AC_TYPE_UINT64_T
 AC_TYPE_UINT8_T
 
-# More rules
+##############
+# MORE RULES #
+##############
 
 AM_SILENT_RULES([yes])
 AM_PROG_AR
@@ -67,10 +71,10 @@ AC_PROG_CC
 AC_PROG_INSTALL
 AM_PROG_AS
 
-# Little or big endian
-LKT_ENDIANES_LITTLE="$(echo -n I | od -to2 | head -n1 | cut -f2 -d" " | cut -c6)"
+###########
+# OPTIONS #
+###########
 
-# Options
 AC_ARG_WITH([debug],
             [AS_HELP_STRING([--with-debug],
                             [Enable debug so you can use gdb])],
@@ -103,7 +107,19 @@ LKT_BUILD_STRING="$CC $(uname -r) $(uname -m)"
 AC_DEFINE_UNQUOTED([LKT_BUILD_STRING], ["$LKT_BUILD_STRING"], [Build string])
 AC_SUBST([LKT_BUILD_STRING])
 
-# CFLAGS
+LKT_ENDIANES_LITTLE="$(echo -n I | od -to2 | head -n1 | cut -f2 -d" " | cut -c6)"
+if test "$LKT_ENDIANES_LITTLE" = "1" ; then
+    AC_DEFINE_UNQUOTED([LKT_ENDIANES_LITTLE], [], [Little endian])
+    AC_SUBST([LKT_ENDIANES_LITTLE])
+else
+    AC_DEFINE_UNQUOTED([LKT_ENDIANES_BIG], [], [Big endian])
+    AC_SUBST([LKT_ENDIANES_BIG])
+fi
+
+##########
+# CFLAGS #
+##########
+
 BASEFLAGS="-Werror -Wall -I../inc/"
 if test "x${LKT_DEBUG_ENABLED}" = "xyes"; then
     BASEFLAGS+=" -g"
@@ -112,7 +128,10 @@ else
 fi
 CFLAGS="${BASEFLAGS} -std=c18"
 
-# Output
+##########
+# OUTPUT #
+##########
+
 AC_CONFIG_HEADERS([inc/lektor/lktconfig.h])
 AC_OUTPUT([
     Makefile
@@ -120,7 +139,10 @@ AC_OUTPUT([
     src/Makefile
 ])
 
-# Conf result
+################
+# CONF RESULTS #
+################
+
 LKT_CONFIG_RESULT="
 ########## Lektor configuration ###########
 #