This chapter describes command-line options available in all versions of the gnu assembler; see Machine Dependencies , for options specific to particular machine architectures.
If you are invoking as via the gnu C compiler, you can use the ‘ -Wa ’ option to pass arguments through to the assembler. The assembler arguments must be separated from each other (and the ‘ -Wa ’) by commas. For example:
gcc -c -g -O -Wa,-alh,-L file.c
This passes two options to the assembler: ‘ -alh ’ (emit a listing to standard output with high-level and assembly source) and ‘ -L ’ (retain local symbols in the symbol table).
Usually you do not need to use this ‘ -Wa ’ mechanism, since many compiler command-line options are automatically passed to the assembler by the compiler. (You can call the gnu compiler driver with the ‘ -v ’ option to see precisely what options it passes to each compilation pass, including the assembler.)