When processing cmdline arguments in DPDK, we always do so with very little context. So, for example, when processing the "-l" flag, we have no idea whether there will be later a --proc-type=secondary flag. We have all sorts of post-arg-processing checks in place to try and catch these scenarios.
To improve this situation, this patchset tries to simplify the handling of argument processing, by explicitly doing an initial pass to collate all arguments into a structure. Thereafter, the actual arg parsing is done in a fixed order, meaning that e.g. when processing the --main-lcore flag, we have already processed the service core flags. We also can far quicker and easier check for conflicting options, since they can all be checked for NULL/non-NULL in the arg structure immediately after the struct has been populated. To do the initial argument gathering, this RFC uses the existing argparse library in DPDK. With recent changes, and two additional patches at the start of this set, this library now meets our needs for EAL argument parsing and allows us to not need to do direct getopt argument processing inside EAL at all. An additional benefit of this work, is that the argument parsing for EAL is much more centralised into common options. This single list with ifdefs makes it clear to the viewer what options are common across OS's, vs what are unix-only or linux-only. Bruce Richardson (9): build: add define for the OS environment name argparse: export function to print help text for object argparse: allow user-override of help printing eal: add long options for each short option eal: define the EAL parameters in argparse format eal: gather EAL args before processing eal: ensure proper cleanup on EAL init failure eal: combine parameter validation checks eal: simplify handling of conflicting cmdline options config/meson.build | 1 + doc/guides/contributing/design.rst | 2 +- doc/guides/linux_gsg/eal_args.include.rst | 20 +- doc/guides/prog_guide/argparse_lib.rst | 16 + lib/argparse/rte_argparse.c | 46 +- lib/argparse/rte_argparse.h | 21 +- lib/eal/common/eal_common_memory.c | 3 +- lib/eal/common/eal_common_options.c | 1299 +++++++++++---------- lib/eal/common/eal_options.h | 102 +- lib/eal/common/eal_private.h | 11 + lib/eal/freebsd/eal.c | 245 +--- lib/eal/linux/eal.c | 470 +------- lib/eal/linux/eal_memory.c | 2 +- lib/eal/meson.build | 2 +- lib/eal/windows/eal.c | 156 +-- lib/meson.build | 1 + 16 files changed, 954 insertions(+), 1443 deletions(-) -- 2.48.1
