Merge pull request #2004 from dangnhat/cpp_for_iot_lab_m3

iot-lab_m3: C++ support

boards/iot-lab_M3/Makefile.features

@@ -1 +1 @@
-FEATURES_PROVIDED += transceiver periph_gpio periph_uart periph_spi periph_i2c periph_rtt periph_cpuid
+FEATURES_PROVIDED += transceiver periph_gpio periph_uart periph_spi periph_i2c periph_rtt periph_cpuid cpp

boards/iot-lab_M3/Makefile.include

@@ -17,6 +17,7 @@ export PORT
 # define tools used for building the project
 export PREFIX = arm-none-eabi-
 export CC = $(PREFIX)gcc
+export CXX = $(PREFIX)g++
 export AR = $(PREFIX)ar
 export AS = $(PREFIX)as
 export LINK = $(PREFIX)gcc
@@ -32,6 +33,11 @@ export CPU_USAGE = -mcpu=cortex-m3
 export FPU_USAGE =
 export CFLAGS += -ggdb -g3 -std=gnu99 -Os -Wall -Wstrict-prototypes $(CPU_USAGE) $(FPU_USAGE) -mlittle-endian -mthumb -mthumb-interwork -nostartfiles
 export CFLAGS += -ffunction-sections -fdata-sections -fno-builtin
+
+# unwanted (CXXUWFLAGS) and extra (CXXEXFLAGS) flags for c++
+export CXXUWFLAGS +=
+export CXXEXFLAGS +=
+
 export ASFLAGS += -ggdb -g3 $(CPU_USAGE) $(FPU_USAGE) -mlittle-endian
 export LINKFLAGS += -ggdb -g3 -std=gnu99 $(CPU_USAGE) $(FPU_USAGE) -mlittle-endian -static -lgcc -mthumb -mthumb-interwork -nostartfiles
 # $(LINKERSCRIPT) is specified in cpu/Makefile.include

cpu/stm32f1/syscalls.c

@@ -156,12 +156,29 @@ int _getpid(void)
  *
  * @return      TODO
  */
+__attribute__ ((weak))
 int _kill_r(struct _reent *r, int pid, int sig)
 {
     r->_errno = ESRCH;                      /* not implemented yet */
     return -1;
 }
 
+/**
+ * @brief Send a signal to a given thread (non-reentrant syscall)
+ *
+ * @param r     TODO
+ * @param pid   TODO
+ * @param sig   TODO
+ *
+ * @return      TODO
+ */
+__attribute__ ((weak))
+int _kill(int pid, int sig)
+{
+    errno = ESRCH;		                   /* not implemented yet */
+    return -1;
+}
+
 /**
  * @brief Open a file
  *