Add option to build tox-bootstrapd

When cross-compiling to <target> from Linux, cmake might find native Linux
libconfig and decide to build tox-bootstrapd. If the target is Windows, this
will fail, as tox-bootstrapd can't be built for Windows in the first place. If
the target is Linux of some other architecture, then using host native
libconfig will fail too. Thus an option is needed to guard against this.

CMakeLists.txt

@@ -304,7 +304,12 @@ add_c_executable(DHT_bootstrap
   other/bootstrap_node_packets.c)
 target_link_modules(DHT_bootstrap toxnetcrypto)
 
-if(LIBCONFIG_FOUND)
+option(BOOTSTRAP_DAEMON "Enable building of tox-bootstrapd" ON)
+if(BOOTSTRAP_DAEMON)
+  if(WIN32)
+    message(FATAL_ERROR "Building tox-bootstrapd for Windows is not supported")
+  endif()
+  if(LIBCONFIG_FOUND)
     add_c_executable(tox-bootstrapd
       other/bootstrap_daemon/src/command_line_arguments.c
       other/bootstrap_daemon/src/command_line_arguments.h
@@ -318,6 +323,7 @@ if(LIBCONFIG_FOUND)
       other/bootstrap_node_packets.c
       other/bootstrap_node_packets.h)
     target_link_modules(tox-bootstrapd toxnetcrypto ${LIBCONFIG_LIBRARIES})
+  endif()
 endif()
 
 ################################################################################

other/travis/env-linux.sh

@@ -1,6 +1,7 @@
 #!/bin/sh
 
 CMAKE=cmake
+CMAKE_EXTRA_FLAGS=""
 NPROC=`nproc`
 CURDIR=$PWD
 

other/travis/env-osx.sh

@@ -1,6 +1,7 @@
 #!/bin/sh
 
 CMAKE=cmake
+CMAKE_EXTRA_FLAGS=""
 NPROC=`sysctl -n hw.ncpu`
 CURDIR=$PWD
 

other/travis/env-windows.sh

@@ -1,6 +1,7 @@
 #!/bin/sh
 
 CMAKE=$ARCH-w64-mingw32.shared-cmake
+CMAKE_EXTRA_FLAGS="-DBOOTSTRAP_DAEMON=OFF"
 NPROC=`nproc`
 CURDIR=/work
 

other/travis/toxcore-script

@@ -13,7 +13,8 @@ RUN $CMAKE                                     \
   -DDEBUG=ON                                   \
   -DASSOC_DHT=ON                               \
   -DSTRICT_ABI=ON                              \
-  -DTEST_TIMEOUT_SECONDS=300 #-DASAN=ON
+  -DTEST_TIMEOUT_SECONDS=300                   \
+  $CMAKE_EXTRA_FLAGS #-DASAN=ON
 
 export CTEST_OUTPUT_ON_FAILURE=1