feat: default language standards set to gnu C/C++17

Signed-off-by: Frederic Pillon <[email protected]>

Author: fpistm

Diff for: platform.txt

@@ -32,7 +32,7 @@ compiler.extra_flags=-mcpu={build.mcu} {build.fpu} {build.float-abi} -DUSE_FULL_
 
 compiler.S.flags={compiler.extra_flags} -c -x assembler-with-cpp {compiler.stm.extra_include}
 
-compiler.c.flags={compiler.extra_flags} -c {build.flags.optimize} {build.flags.debug} {compiler.warning_flags} -std=gnu11 -ffunction-sections -fdata-sections --param max-inline-insns-single=500 -MMD {compiler.stm.extra_include}
+compiler.c.flags={compiler.extra_flags} -c {build.flags.optimize} {build.flags.debug} {compiler.warning_flags} -std={compiler.c.std} -ffunction-sections -fdata-sections --param max-inline-insns-single=500 -MMD {compiler.stm.extra_include}
 
 compiler.cpp.flags={compiler.extra_flags} -c {build.flags.optimize} {build.flags.debug} {compiler.warning_flags} -std={compiler.cpp.std} -ffunction-sections -fdata-sections -fno-threadsafe-statics --param max-inline-insns-single=500 -fno-rtti -fno-exceptions -fno-use-cxa-atexit -MMD {compiler.stm.extra_include}
 
@@ -59,9 +59,10 @@ build.variant_h=variant_generic.h
 # These can be overridden in platform.local.txt
 compiler.c.st_extra_flags={build.peripheral_pins}
 compiler.c.extra_flags=
+compiler.c.std=gnu17
 compiler.c.elf.extra_flags=
 compiler.cpp.extra_flags=
-compiler.cpp.std=gnu++14
+compiler.cpp.std=gnu++17
 compiler.S.st_extra_flags={build.startup_file}
 compiler.S.extra_flags=
 compiler.ar.extra_flags=