XL C/C++ supports a number of common conventional flag options used on UNIX® systems. Lowercase flags are different from their corresponding uppercase flags. For example, -c and -C are two different compiler options: -c specifies that the compiler should only preprocess and compile and not invoke the linker, while -C can be used with -P or -E to specify that user comments should be preserved.
XL C/C++ also supports flags directed to other programming tools and utilities (for example, the ld command). The compiler passes on those flags directed to ld at link time.
xlc stem.c -F/home/tools/test3/new.cfg:xlcwhere new.cfg is a custom configuration file.
xlc -Ocv file.chas the same effect as:
xlc -O -c -v file.c
and compiles the C source file file.c with optimization (-O) and reports on compiler progress (-v), but does not invoke the linker (-c).
xlc -Ovo test test.chas the same effect as:
xlc -O -v -otest test.c
Most flag options are a single letter, but some are two letters. Note that specifying -pg (extended profiling) is not the same as specifying -p -g (-p for profiling, and -g for generating debug information). Take care not to specify two or more options in a single string if there is another option that uses that letter combination.