Re: [Qemu-devel] [PATCH v2 03/29] qapi: Split error.json off common.json

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 8/6/19 5:14 PM, Markus Armbruster wrote:
> In my "build everything" tree, changing a type in qapi/common.json
> triggers a recompile of some 3600 out of 6600 objects (not counting
> tests and objects that don't depend on qemu/osdep.h).
> 
> One common dependency is QapiErrorClass: it's used only in in
> qapi/error.h, which uses nothing else, and is widely included.
> 
> Move QapiErrorClass from common.json to new error.json.  Touching
> common.json now recompiles only some 2900 objects.

Nice.

> 
> Cc: Eric Blake <eblake@redhat.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---
>  MAINTAINERS           |  2 ++
>  include/qapi/error.h  |  2 +-
>  qapi/Makefile.objs    |  2 +-
>  qapi/common.json      | 24 ------------------------
>  qapi/error.json       | 29 +++++++++++++++++++++++++++++
>  qapi/qapi-schema.json |  1 +
>  6 files changed, 34 insertions(+), 26 deletions(-)
>  create mode 100644 qapi/error.json
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d6de200453..adc64cfe33 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1874,6 +1874,7 @@ M: Markus Armbruster <armbru@redhat.com>
>  S: Supported
>  F: include/qapi/error.h
>  F: include/qemu/error-report.h
> +F: qapi/error.json
>  F: util/error.c
>  F: util/qemu-error.c
>  
> @@ -2062,6 +2063,7 @@ F: monitor/monitor-internal.h
>  F: monitor/qmp*
>  F: monitor/misc.c
>  F: monitor/monitor.c
> +F: qapi/error.json
>  F: docs/devel/*qmp-*
>  F: docs/interop/*qmp-*
>  F: scripts/qmp/
> diff --git a/include/qapi/error.h b/include/qapi/error.h
> index 51b63dd4b5..3f95141a01 100644
> --- a/include/qapi/error.h
> +++ b/include/qapi/error.h
> @@ -119,7 +119,7 @@
>  #ifndef ERROR_H
>  #define ERROR_H
>  
> -#include "qapi/qapi-types-common.h"
> +#include "qapi/qapi-types-error.h"
>  
>  /*
>   * Overall category of an error.
> diff --git a/qapi/Makefile.objs b/qapi/Makefile.objs
> index c5a29e86e2..dd3f5e6f94 100644
> --- a/qapi/Makefile.objs
> +++ b/qapi/Makefile.objs
> @@ -6,7 +6,7 @@ util-obj-y += qmp-event.o
>  util-obj-y += qapi-util.o
>  
>  QAPI_COMMON_MODULES = audio authz block-core block char common crypto
> -QAPI_COMMON_MODULES += dump introspect job machine migration misc net
> +QAPI_COMMON_MODULES += dump error introspect job machine migration misc net
>  QAPI_COMMON_MODULES += qdev qom rdma rocker run-state sockets tpm
>  QAPI_COMMON_MODULES += trace transaction ui
>  QAPI_TARGET_MODULES = machine-target misc-target
> diff --git a/qapi/common.json b/qapi/common.json
> index 99d313ef3b..3d4e8de1e0 100644
> --- a/qapi/common.json
> +++ b/qapi/common.json
> @@ -4,30 +4,6 @@
>  # = Common data types
>  ##
>  
> -##
> -# @QapiErrorClass:
> -#
> -# QEMU error classes
> -#
> -# @GenericError: this is used for errors that don't require a specific error
> -#                class. This should be the default case for most errors
> -#
> -# @CommandNotFound: the requested command has not been found
> -#
> -# @DeviceNotActive: a device has failed to be become active
> -#
> -# @DeviceNotFound: the requested device has not been found
> -#
> -# @KVMMissingCap: the requested operation can't be fulfilled because a
> -#                 required KVM capability is missing
> -#
> -# Since: 1.2
> -##
> -{ 'enum': 'QapiErrorClass',
> -  # Keep this in sync with ErrorClass in error.h
> -  'data': [ 'GenericError', 'CommandNotFound',
> -            'DeviceNotActive', 'DeviceNotFound', 'KVMMissingCap' ] }
> -
>  ##
>  # @IoOperationType:
>  #
> diff --git a/qapi/error.json b/qapi/error.json
> new file mode 100644
> index 0000000000..3fad08f506
> --- /dev/null
> +++ b/qapi/error.json
> @@ -0,0 +1,29 @@
> +# -*- Mode: Python -*-
> +
> +##
> +# = QMP errors
> +##
> +
> +##
> +# @QapiErrorClass:
> +#
> +# QEMU error classes
> +#
> +# @GenericError: this is used for errors that don't require a specific error
> +#                class. This should be the default case for most errors
> +#
> +# @CommandNotFound: the requested command has not been found
> +#
> +# @DeviceNotActive: a device has failed to be become active
> +#
> +# @DeviceNotFound: the requested device has not been found
> +#
> +# @KVMMissingCap: the requested operation can't be fulfilled because a
> +#                 required KVM capability is missing
> +#
> +# Since: 1.2
> +##
> +{ 'enum': 'QapiErrorClass',
> +  # Keep this in sync with ErrorClass in error.h
> +  'data': [ 'GenericError', 'CommandNotFound',
> +            'DeviceNotActive', 'DeviceNotFound', 'KVMMissingCap' ] }
> diff --git a/qapi/qapi-schema.json b/qapi/qapi-schema.json
> index 38af54d6b3..920b03b0aa 100644
> --- a/qapi/qapi-schema.json
> +++ b/qapi/qapi-schema.json
> @@ -80,6 +80,7 @@
>  # stable order, it's best to include each sub-schema just once, or
>  # include it first right here.
>  
> +{ 'include': 'error.json' }
>  { 'include': 'common.json' }
>  { 'include': 'sockets.json' }
>  { 'include': 'run-state.json' }
>