[RFC,v2] Use help sub-sections to create sub-help options

As '-help' output is 400 lines long it is not easy
to find information, but generally we know from
which area we want the information.

As subsections already exist in the help description,
add some command options to only display the wanted
subsection.

As more is better, this patch adds 13 lines to the -help output:

    -help-standard  display standard options
    -help-block     display block options
    -help-usb       display usb options
    -help-display   display display options
    -help-machine   display machine options
    -help-network   display network options
    -help-character display character options
    -help-url       display url options
    -help-bt        display bt options
    -help-tpm       display tpm options
    -help-kernel    display kernel options
    -help-expert    display expert options
    -help-object    display object options

Example:

    $ qemu-system-x86_64 -help-kernel
    Linux/Multiboot boot specific:
    -kernel bzImage use 'bzImage' as kernel image
    -append cmdline use 'cmdline' as kernel command line
    -initrd file    use 'file' as initial ram disk
    -dtb    file    use 'file' as device tree image

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
v2: simplify the dance of #define/#undef, thanks to Marc-André.

 qemu-options.hx | 150 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 vl.c            | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 280 insertions(+), 4 deletions(-)

Hi

On Thu, Aug 27, 2015 at 7:07 PM, Laurent Vivier <lvivier@redhat.com> wrote:
> As '-help' output is 400 lines long it is not easy
> to find information, but generally we know from
> which area we want the information.
>
> As subsections already exist in the help description,
> add some command options to only display the wanted
> subsection.
>
> As more is better, this patch adds 13 lines to the -help output:
>
>     -help-standard  display standard options
>     -help-block     display block options
>     -help-usb       display usb options
>     -help-display   display display options
>     -help-machine   display machine options
>     -help-network   display network options
>     -help-character display character options
>     -help-url       display url options
>     -help-bt        display bt options
>     -help-tpm       display tpm options
>     -help-kernel    display kernel options
>     -help-expert    display expert options
>     -help-object    display object options
>
> Example:
>
>     $ qemu-system-x86_64 -help-kernel
>     Linux/Multiboot boot specific:
>     -kernel bzImage use 'bzImage' as kernel image
>     -append cmdline use 'cmdline' as kernel command line
>     -initrd file    use 'file' as initial ram disk
>     -dtb    file    use 'file' as device tree image
>
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---
> v2: simplify the dance of #define/#undef, thanks to Marc-André.
>
>  qemu-options.hx | 150 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
>  vl.c            | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 280 insertions(+), 4 deletions(-)
>


Looks good to me & works fine

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

I would prefer to not have all the --help-* in --help-standard, but
that's quite minor. But if you agree, it's perhaps worth the extra
effort though

thanks


> diff --git a/qemu-options.hx b/qemu-options.hx
> index 77f5853..49b78df 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -6,17 +6,123 @@ HXCOMM construct option structures, enums and help message for specified
>  HXCOMM architectures.
>  HXCOMM HXCOMM can be used for comments, discarded from both texi and C
>
> +#if defined(QEMU_HELP_SELECT_STANDARD) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_STANDARD
>  DEFHEADING(Standard options:)
>  STEXI
>  @table @option
>  ETEXI
>
>  DEF("help", 0, QEMU_OPTION_h,
> -    "-h or -help     display this help and exit\n", QEMU_ARCH_ALL)
> +    "-h or -help     display all help options and exit\n", QEMU_ARCH_ALL)
>  STEXI
>  @item -h
>  @findex -h
> -Display help and exit
> +Display all help options and exit
> +ETEXI
> +
> +DEF("help-standard", 0, QEMU_OPTION_h_standard,
> +    "-help-standard  display standard options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-standard
> +@findex -help-standard
> +Display standard options
> +ETEXI
> +
> +DEF("help-block", 0, QEMU_OPTION_h_block,
> +    "-help-block     display block options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-block
> +@findex -help-block
> +Display block options
> +ETEXI
> +
> +DEF("help-usb", 0, QEMU_OPTION_h_usb,
> +    "-help-usb       display usb options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-usb
> +@findex -help-usb
> +Display usb options
> +ETEXI
> +
> +DEF("help-display", 0, QEMU_OPTION_h_display,
> +    "-help-display   display display options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-display
> +@findex -help-display
> +Display display options
> +ETEXI
> +
> +DEF("help-machine", 0, QEMU_OPTION_h_machine,
> +    "-help-machine   display machine options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-machine
> +@findex -help-machine
> +Display machine options
> +ETEXI
> +
> +DEF("help-network", 0, QEMU_OPTION_h_network,
> +    "-help-network   display network options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-network
> +@findex -help-network
> +Display network options
> +ETEXI
> +
> +DEF("help-character", 0, QEMU_OPTION_h_character,
> +    "-help-character display character options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-character
> +@findex -help-character
> +Display character options
> +ETEXI
> +
> +DEF("help-url", 0, QEMU_OPTION_h_url,
> +    "-help-url       display url options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-url
> +@findex -help-url
> +Display url options
> +ETEXI
> +
> +DEF("help-bt", 0, QEMU_OPTION_h_bt,
> +    "-help-bt        display bt options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-bt
> +@findex -help-bt
> +Display bt options
> +ETEXI
> +
> +DEF("help-tpm", 0, QEMU_OPTION_h_tpm,
> +    "-help-tpm       display tpm options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-tpm
> +@findex -help-tpm
> +Display tpm options
> +ETEXI
> +
> +DEF("help-kernel", 0, QEMU_OPTION_h_kernel,
> +    "-help-kernel    display kernel options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-kernel
> +@findex -help-kernel
> +Display kernel options
> +ETEXI
> +
> +DEF("help-expert", 0, QEMU_OPTION_h_expert,
> +    "-help-expert    display expert options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-expert
> +@findex -help-expert
> +Display expert options
> +ETEXI
> +
> +DEF("help-object", 0, QEMU_OPTION_h_object,
> +    "-help-object    display object options\n", QEMU_ARCH_ALL)
> +STEXI
> +@item -help-object
> +@findex -help-object
> +Display object options
>  ETEXI
>
>  DEF("version", 0, QEMU_OPTION_version,
> @@ -410,7 +516,10 @@ STEXI
>  @end table
>  ETEXI
>  DEFHEADING()
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_BLOCK) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_BLOCK
>  DEFHEADING(Block device options:)
>  STEXI
>  @table @option
> @@ -798,7 +907,10 @@ STEXI
>  @end table
>  ETEXI
>  DEFHEADING()
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_USB) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_USB
>  DEFHEADING(USB options:)
>  STEXI
>  @table @option
> @@ -862,7 +974,10 @@ STEXI
>  @end table
>  ETEXI
>  DEFHEADING()
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_DISPLAY) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_DISPLAY
>  DEFHEADING(Display options:)
>  STEXI
>  @table @option
> @@ -1329,7 +1444,10 @@ STEXI
>  @end table
>  ETEXI
>  ARCHHEADING(, QEMU_ARCH_I386)
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_MACHINE) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_MACHINE
>  ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
>  STEXI
>  @table @option
> @@ -1441,7 +1559,10 @@ STEXI
>  @end table
>  ETEXI
>  DEFHEADING()
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_NETWORK) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_NETWORK
>  DEFHEADING(Network options:)
>  STEXI
>  @table @option
> @@ -1995,7 +2116,10 @@ STEXI
>  @end table
>  ETEXI
>  DEFHEADING()
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_CHARACTER) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_CHARACTER
>  DEFHEADING(Character device options:)
>  STEXI
>
> @@ -2273,7 +2397,10 @@ STEXI
>  @end table
>  ETEXI
>  DEFHEADING()
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_URL) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_URL
>  DEFHEADING(Device URL Syntax:)
>  STEXI
>
> @@ -2482,7 +2609,10 @@ ETEXI
>  STEXI
>  @end table
>  ETEXI
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_BT) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_BT
>  DEFHEADING(Bluetooth(R) options:)
>  STEXI
>  @table @option
> @@ -2557,7 +2687,10 @@ STEXI
>  @end table
>  ETEXI
>  DEFHEADING()
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_TPM) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_TPM
>  #ifdef CONFIG_TPM
>  DEFHEADING(TPM device options:)
>
> @@ -2632,7 +2765,10 @@ ETEXI
>  DEFHEADING()
>
>  #endif
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_KERNEL) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_KERNEL
>  DEFHEADING(Linux/Multiboot boot specific:)
>  STEXI
>
> @@ -2688,7 +2824,10 @@ STEXI
>  @end table
>  ETEXI
>  DEFHEADING()
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_EXPERT) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_EXPERT
>  DEFHEADING(Debug/Expert options:)
>  STEXI
>  @table @option
> @@ -3510,7 +3649,7 @@ DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
>      "                Output vmstate information in JSON format to file.\n"
>      "                Use the scripts/vmstate-static-checker.py file to\n"
>      "                check for possible regressions in migration code\n"
> -    "                by comparing two such vmstate dumps.",
> +    "                by comparing two such vmstate dumps.\n",
>      QEMU_ARCH_ALL)
>  STEXI
>  @item -dump-vmstate @var{file}
> @@ -3518,7 +3657,10 @@ STEXI
>  Dump json-encoded vmstate information for current machine type to file
>  in @var{file}
>  ETEXI
> +#endif
>
> +#if defined(QEMU_HELP_SELECT_OBJECT) || !defined(QEMU_HELP_SELECT)
> +#undef QEMU_HELP_SELECT_OBJECT
>  DEFHEADING(Generic object creation)
>
>  DEF("object", HAS_ARG, QEMU_OPTION_object,
> @@ -3571,7 +3713,7 @@ to the RNG daemon.
>  @end table
>
>  ETEXI
> -
> +#endif
>
>  HXCOMM This is the last statement. Insert new options before this line!
>  STEXI
> diff --git a/vl.c b/vl.c
> index 584ca88..e581dd2 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -1931,6 +1931,101 @@ static void help(int exitcode)
>      exit(exitcode);
>  }
>
> +#define QEMU_HELP_SELECT
> +static void help_standard(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_STANDARD
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_block(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_BLOCK
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_usb(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_USB
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_display(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_DISPLAY
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_machine(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_MACHINE
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_network(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_NETWORK
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_character(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_CHARACTER
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_url(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_URL
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_bt(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_BT
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_tpm(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_TPM
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_kernel(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_KERNEL
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_expert(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_EXPERT
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +static void help_object(int exitcode)
> +{
> +#define QEMU_HELP_SELECT_OBJECT
> +#define QEMU_OPTIONS_GENERATE_HELP
> +#include "qemu-options-wrapper.h"
> +    exit(exitcode);
> +}
> +#undef QEMU_HELP_SELECT
> +
> +
>  #define HAS_ARG 0x0001
>
>  typedef struct QEMUOption {
> @@ -3318,6 +3413,42 @@ int main(int argc, char **argv, char **envp)
>              case QEMU_OPTION_h:
>                  help(0);
>                  break;
> +            case QEMU_OPTION_h_standard:
> +                help_standard(0);
> +                break;
> +            case QEMU_OPTION_h_block:
> +                help_block(0);
> +                break;
> +            case QEMU_OPTION_h_usb:
> +                help_usb(0);
> +                break;
> +            case QEMU_OPTION_h_display:
> +                help_display(0);
> +                break;
> +            case QEMU_OPTION_h_machine:
> +                help_machine(0);
> +                break;
> +            case QEMU_OPTION_h_network:
> +                help_network(0);
> +                break;
> +            case QEMU_OPTION_h_character:
> +                help_character(0);
> +                break;
> +            case QEMU_OPTION_h_url:
> +                help_url(0);
> +                break;
> +            case QEMU_OPTION_h_bt:
> +                help_bt(0);
> +                break;
> +            case QEMU_OPTION_h_kernel:
> +                help_kernel(0);
> +                break;
> +            case QEMU_OPTION_h_expert:
> +                help_expert(0);
> +                break;
> +            case QEMU_OPTION_h_object:
> +                help_object(0);
> +                break;
>              case QEMU_OPTION_version:
>                  version();
>                  exit(0);
> @@ -3330,6 +3461,9 @@ int main(int argc, char **argv, char **envp)
>                  }
>                  break;
>  #ifdef CONFIG_TPM
> +            case QEMU_OPTION_h_tpm:
> +                help_tpm(0);
> +                break;
>              case QEMU_OPTION_tpmdev:
>                  if (tpm_config_parse(qemu_find_opts("tpmdev"), optarg) < 0) {
>                      exit(1);
> --
> 2.1.0
>