package/mraa: drop C++ dependency

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/mraa/0002-CMakeLists.txt-add-BUILDCPP-option.patch

@@ -0,0 +1,193 @@
+From cb88e4dd1fbbb9d24e625dba2768b88ed99da309 Mon Sep 17 00:00:00 2001
+From: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+Date: Sat, 13 Jun 2020 22:51:37 +0200
+Subject: [PATCH] CMakeLists.txt: add BUILDCPP option
+
+C++ is a mandatory dependency since version 1.4.0 and
+https://github.com/eclipse/mraa/commit/122cab1f1e53b7c9c7cd82905b962071f9bad9dc
+
+As a result, build on embedded toolchains that do not support C++ fails
+on:
+
+CMake Error at CMakeLists.txt:2 (project):
+  The CMAKE_CXX_COMPILER:
+
+    /home/naourr/work/instance-1/output-1/per-package/mraa/host/bin/arm-linux-g++
+
+  is not a full path to an existing compiler tool.
+
+Fixes:
+ - http://autobuild.buildroot.org/results/31086422e03611c16ab59c4418e3669b580bc0c0
+
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+[Retrieved from:
+https://github.com/eclipse/mraa/commit/cb88e4dd1fbbb9d24e625dba2768b88ed99da309]
+---
+ CMakeLists.txt                | 69 +++++++++++++++++++----------------
+ src/java/CMakeLists.txt       |  4 +-
+ src/javascript/CMakeLists.txt | 34 +++++++++--------
+ 3 files changed, 59 insertions(+), 48 deletions(-)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 250d9106e..90c0dc920 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -1,5 +1,5 @@
+ cmake_minimum_required (VERSION 2.8.11)
+-project (mraa C CXX)
++project (mraa C)
+ 
+ FIND_PACKAGE (Threads REQUIRED)
+ 
+@@ -11,6 +11,8 @@ else ()
+   set (CMAKE_C_STANDARD 99)
+ endif ()
+ 
++option (BUILDCPP "Enable C++ (needed by FTDI4222 and tests)" ON)
++
+ ###############################################################################
+ # Detect supported warning flags
+ # Modified from work By Dan Liew (fpbench - MIT)
+@@ -33,15 +35,18 @@ set (MRAA_C_WARNING_FLAGS
+   -Werror=missing-parameter-type
+ )
+ 
+-# Warning flags for the C++ compiler only
+-set (MRAA_CXX_WARNING_FLAGS
+-  -Wnon-virtual-dtor
+-  -Woverloaded-virtual
+-  -Wreorder
+-)
+-
+ include (CheckCCompilerFlag)
+-include (CheckCXXCompilerFlag)
++if (BUILDCPP)
++  # Warning flags for the C++ compiler only
++  set (MRAA_CXX_WARNING_FLAGS
++    -Wnon-virtual-dtor
++    -Woverloaded-virtual
++    -Wreorder
++  )
++
++  enable_language (CXX)
++  include (CheckCXXCompilerFlag)
++endif ()
+ function (MRAA_SANITIZE_FLAG_NAME OUTPUT_VAR FLAG)
+   string (REPLACE "-" "_" SANITIZED_FLAG_NAME "${FLAG}")
+   string (REPLACE "/" "_" SANITIZED_FLAG_NAME "${SANITIZED_FLAG_NAME}")
+@@ -62,28 +67,30 @@ foreach (flag ${MRAA_BOTH_WARNING_FLAGS} ${MRAA_C_WARNING_FLAGS})
+   endif ()
+ endforeach ()
+ 
+-# Globally set C++ compiler warning flags that are supported and emit
+-# a warning about unsupported flags
+-foreach (flag ${MRAA_BOTH_WARNING_FLAGS} ${MRAA_CXX_WARNING_FLAGS})
+-  MRAA_SANITIZE_FLAG_NAME (SANITIZED_FLAG_NAME "${flag}")
+-  CHECK_CXX_COMPILER_FLAG ("${flag}" HAS_CXX_${SANITIZED_FLAG_NAME})
+-  if (HAS_CXX_${SANITIZED_FLAG_NAME})
+-    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}")
+-  else ()
+-    message (WARNING "C++ compiler does not support flag \"${flag}\"")
+-  endif ()
+-endforeach ()
+-
+-# This function adds the c++11 flag to a c++ target (if supported)
+-function(use_cxx_11 targetname)
+-  include(CheckCXXCompilerFlag)
+-  CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
+-  if (COMPILER_SUPPORTS_CXX11)
+-    set_target_properties(${targetname} PROPERTIES COMPILE_FLAGS "-std=c++11")
+-  else()
+-    message(FATAL_ERROR "Target '${targetname}' requires c++11 which is not supported by this compiler")
+-  endif()
+-endfunction()
++if (BUILDCPP)
++  # Globally set C++ compiler warning flags that are supported and emit
++  # a warning about unsupported flags
++  foreach (flag ${MRAA_BOTH_WARNING_FLAGS} ${MRAA_CXX_WARNING_FLAGS})
++    MRAA_SANITIZE_FLAG_NAME (SANITIZED_FLAG_NAME "${flag}")
++    CHECK_CXX_COMPILER_FLAG ("${flag}" HAS_CXX_${SANITIZED_FLAG_NAME})
++    if (HAS_CXX_${SANITIZED_FLAG_NAME})
++      set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}")
++    else ()
++      message (WARNING "C++ compiler does not support flag \"${flag}\"")
++    endif ()
++  endforeach ()
++
++  # This function adds the c++11 flag to a c++ target (if supported)
++  function(use_cxx_11 targetname)
++    include(CheckCXXCompilerFlag)
++    CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
++    if (COMPILER_SUPPORTS_CXX11)
++      set_target_properties(${targetname} PROPERTIES COMPILE_FLAGS "-std=c++11")
++    else()
++      message(FATAL_ERROR "Target '${targetname}' requires c++11 which is not supported by this compiler")
++    endif()
++  endfunction()
++endif()
+ 
+ # Set CMAKE_INSTALL_LIBDIR if not defined
+ include(GNUInstallDirs)
+diff --git a/src/java/CMakeLists.txt b/src/java/CMakeLists.txt
+index 231c755fa..cfa72a0df 100644
+--- a/src/java/CMakeLists.txt
++++ b/src/java/CMakeLists.txt
+@@ -16,7 +16,9 @@ include_directories (
+ set_source_files_properties (mraajava.i PROPERTIES SWIG_FLAGS ";-package;mraa;-I${CMAKE_BINARY_DIR}/src")
+ set_source_files_properties (mraajava.i PROPERTIES CPLUSPLUS ON)
+ 
+-set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fpermissive -DJAVACALLBACK")
++if (BUILDCPP)
++  set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fpermissive -DJAVACALLBACK")
++endif()
+ set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DJAVACALLBACK")
+ 
+ if (NOT DEFINED ENV{JAVA_HOME_NATIVE})
+diff --git a/src/javascript/CMakeLists.txt b/src/javascript/CMakeLists.txt
+index 25fd36275..99a96b49d 100644
+--- a/src/javascript/CMakeLists.txt
++++ b/src/javascript/CMakeLists.txt
+@@ -36,25 +36,27 @@ set_target_properties (mraajs PROPERTIES
+ )
+ 
+ message (STATUS "INFO - swig Version ${SWIG_VERSION}")
+-message (STATUS "INFO - CXX compiler Version ${CMAKE_CXX_COMPILER_ID} ${CMAKE_CXX_COMPILER_VERSION}")
++if (BUILDCPP)
++  message (STATUS "INFO - CXX compiler Version ${CMAKE_CXX_COMPILER_ID} ${CMAKE_CXX_COMPILER_VERSION}")
+ 
+-if (${V8_VERSION_MAJOR} GREATER 3)
+-  message (STATUS "INFO - Using V8 version > 3 so requiring C++11 compiler")
+-  # Node 0.12.x V8 engine major version is '3'.
+-  # Node 2.1.0  V8 engine major version is '4'.
+-  set_property (TARGET mraajs PROPERTY CXX_STANDARD 11)
+-  set_property (TARGET mraajs PROPERTY CXX_STANDARD_REQUIRED ON)
+-  if (CMAKE_VERSION VERSION_LESS "3.1")
+-    message (WARNING "Need to use CMAKE version 3.1+, but it is ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}.${CMAKE_PATCH_VERSION}, using a workaround.")
+-    if (CMAKE_COMPILER_IS_GNUCXX)
+-      if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS "4.7")
+-        message (FATAL_ERROR "GNU gcc compiler is also too old (need 4.7+, but ${CMAKE_CXX_COMPILER_VERSION}) and does not support C++11 standard.")
++  if (${V8_VERSION_MAJOR} GREATER 3)
++    message (STATUS "INFO - Using V8 version > 3 so requiring C++11 compiler")
++    # Node 0.12.x V8 engine major version is '3'.
++    # Node 2.1.0  V8 engine major version is '4'.
++    set_property (TARGET mraajs PROPERTY CXX_STANDARD 11)
++    set_property (TARGET mraajs PROPERTY CXX_STANDARD_REQUIRED ON)
++    if (CMAKE_VERSION VERSION_LESS "3.1")
++      message (WARNING "Need to use CMAKE version 3.1+, but it is ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}.${CMAKE_PATCH_VERSION}, using a workaround.")
++      if (CMAKE_COMPILER_IS_GNUCXX)
++        if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS "4.7")
++          message (FATAL_ERROR "GNU gcc compiler is also too old (need 4.7+, but ${CMAKE_CXX_COMPILER_VERSION}) and does not support C++11 standard.")
++        endif ()
++        set (MRAA_CXX11_WORKAROUND_OPTION "-std=gnu++11")
++      else ()
++        set (MRAA_CXX11_WORKAROUND_OPTION "-std=c++11")
+       endif ()
+-      set (MRAA_CXX11_WORKAROUND_OPTION "-std=gnu++11")
+-    else ()
+-      set (MRAA_CXX11_WORKAROUND_OPTION "-std=c++11")
++      set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${MRAA_CXX11_WORKAROUND_OPTION} ")
+     endif ()
+-    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${MRAA_CXX11_WORKAROUND_OPTION} ")
+   endif ()
+ endif ()
+ 

package/mraa/Config.in

@@ -9,7 +9,6 @@ config BR2_PACKAGE_MRAA
 	bool "mraa"
 	depends on BR2_PACKAGE_MRAA_ARCH_SUPPORTS
 	depends on !BR2_STATIC_LIBS
-	depends on BR2_INSTALL_LIBSTDCPP
 	depends on BR2_TOOLCHAIN_HAS_THREADS
 	help
 	  mraa is a C/C++ library with bindings to javascript & python
@@ -19,7 +18,6 @@ config BR2_PACKAGE_MRAA
 
 	  http://iotdk.intel.com/docs/master/mraa
 
-comment "mraa needs a toolchain w/ C++, threads, dynamic library"
+comment "mraa needs a toolchain w/ threads, dynamic library"
 	depends on BR2_PACKAGE_MRAA_ARCH_SUPPORTS
-	depends on !BR2_INSTALL_LIBSTDCPP || !BR2_TOOLCHAIN_HAS_THREADS \
-		|| BR2_STATIC_LIBS
+	depends on !BR2_TOOLCHAIN_HAS_THREADS || BR2_STATIC_LIBS

package/mraa/mraa.mk

@@ -24,9 +24,10 @@ endif
 
 # USBPLAT only makes sense with FTDI4222, which requires the ftd2xx library,
 # which doesn't exist in buildroot
-
+# Disable C++ as it is used only by FTDI4222 and tests
 MRAA_CONF_OPTS += \
 	-DBUILDARCH=$(MRAA_ARCH) \
+	-DBUILDCPP=OFF \
 	-DBUILDSWIG=OFF \
 	-DUSBPLAT=OFF \
 	-DFTDI4222=OFF \