Make it possible to disable conf.

Now the configure script has --disable-conf command-line argument
that can be used to turn off environment variables and use of
configuration files.

configure.ac

@@ -81,6 +81,17 @@ then
   AC_DEFINE([LOG], [1], [Enable log])
 fi
 
+# Conf support (default:yes)
+AC_ARG_ENABLE([conf],AS_HELP_STRING([--disable-conf],[Disable use of config files and environment variables]),[enable_conf=$enableval],[enable_conf="yes"])
+AC_MSG_CHECKING(for conf flag)
+AC_MSG_RESULT($enable_conf)
+AM_CONDITIONAL([WITH_CONF], [test "$enable_conf" != "no"])
+ 
+if test x"$enable_conf" = "xyes"
+then
+  AC_DEFINE([CONF], [1], [Enable conf])
+fi
+
 # Debug support (default:no)
 AC_ARG_ENABLE([debug],AS_HELP_STRING([--enable-debug],[Enable debug mode]),[enable_debug=$enableval],[enable_debug="no"])
 AC_MSG_CHECKING(for debug flag)

libnfc/conf.c

@@ -21,6 +21,7 @@
 #  include "config.h"
 #endif // HAVE_CONFIG_H
 
+#ifdef CONF
 #include <stdio.h>
 #include <stdlib.h>
 #include <dirent.h>
@@ -189,3 +190,5 @@ conf_load(nfc_context *context)
   conf_devices_load(LIBNFC_DEVICECONFDIR, context);
 }
 
+#endif // CONF
+

libnfc/log-printf.c

@@ -34,9 +34,13 @@
 void
 log_init(const nfc_context *context)
 {
+#ifdef CONF
   char str[32];
   sprintf(str, "%"PRIu32, context->log_level);
   setenv("LIBNFC_LOG_LEVEL", str, 1);
+#else
+  (void)context;
+#endif
 }
 
 void
@@ -47,7 +51,10 @@ log_exit(void)
 void
 log_put(const uint8_t group, const char *category, const uint8_t priority, const char *format, ...)
 {
-  char *env_log_level = getenv("LIBNFC_LOG_LEVEL");
+  char *env_log_level = NULL;
+#ifdef CONF
+  env_log_level = getenv("LIBNFC_LOG_LEVEL");
+#endif
   uint32_t log_level;
   if (NULL == env_log_level) {
     // LIBNFC_LOG_LEVEL is not set

libnfc/nfc-internal.c

@@ -24,7 +24,14 @@
 
 #include <nfc/nfc.h>
 #include "nfc-internal.h"
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef CONF
 #include "conf.h"
+#endif
 
 #include <stdlib.h>
 #include <string.h>
@@ -81,6 +88,7 @@ nfc_context_new(void)
   }
   res->user_defined_device_count = 0;
 
+#ifdef CONF
   // Load user defined device from environment variable at first
   char *envvar = getenv("LIBNFC_DEFAULT_DEVICE");
   if (envvar) {
@@ -102,6 +110,7 @@ nfc_context_new(void)
   if (envvar) {
     res->log_level = atoi(envvar);
   }
+#endif // CONF
 
   // Initialize log before use it...
   log_init(res);

libnfc/nfc.c

@@ -294,6 +294,7 @@ nfc_list_devices(nfc_context *context, nfc_connstring connstrings[], const size_
 {
   size_t device_found = 0;
 
+#ifdef CONF
   // Load manually configured devices (from config file and env variables)
   // TODO From env var...
   for (uint32_t i = 0; i < context->user_defined_device_count; i++) {
@@ -334,6 +335,7 @@ nfc_list_devices(nfc_context *context, nfc_connstring connstrings[], const size_
         return device_found;
     }
   }
+#endif // CONF
 
   // Device auto-detection
   if (context->allow_autoscan) {