This option instructs the compiler to use GCC to retry a failed build step, when building for ARM Linux.
When using armcc in GCC emulation mode, GCC incompatibilities might cause a compile, assembly or link step to fail. Using this option instructs the compiler to automatically retry the failed step using GCC. Any build step that succeeds with the armcc does not get rebuilt using GCC. Each failed step is retried using GCC. For example, if you specify this option for all of the source files in your build and one of them contains an unsupported GNU extension, such as inline assembly code with the GCC syntax, armcc generates a warning and the compiler retries the failed command lines using the GNU tools.
You must escape the option using -Warmcc, for example -Warmcc,--gcc_fallback.
This option can only be used with a GNU emulation mode (that is when using --translate_gcc, --translate_g++, or --translate_gld) and an ARM Linux configuration file specified with --arm_linux_config_file. An existing GNU toolchain must be present (either automatically found on the PATH environment variable or specified with --configure_gcc) to create the configuration file.