build: print list of disabled components

When configuring with meson we print out a list of enabled components, but
it is also useful to list out the disabled components and the reasons why.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Luca Boccassi <bluca@debian.org>

diff --git a/doc/guides/contributing/coding_style.rst b/doc/guides/contributing/coding_style.rst
index a5d5897..449b334 100644 (file)
--- a/doc/guides/contributing/coding_style.rst
+++ b/doc/guides/contributing/coding_style.rst
@@ -852,12 +852,15 @@ allow_experimental_apis
 build
        **Default Value = true**
        Used to optionally compile a library, based on its dependencies or
-       environment. A simple example of use would be:
+       environment. When set to "false" the ``reason`` value, explained below, should
+       also be set to explain to the user why the component is not being built.
+       A simple example of use would be:
 
 .. code-block:: python
 
        if not is_linux
                build = false
+               reason = 'only supported on Linux'
        endif
 
 
@@ -938,6 +941,13 @@ objs
        objects that were compiled up as part of another target given in the
        included library ``meson.build`` file.
 
+reason
+       **Default Value = '<unknown reason>'**.
+       This variable should be used when a library is not to be built i.e. when
+       ``build`` is set to "false", to specify the reason why a library will not be
+       built. For missing dependencies this should be of the form
+       ``'missing dependency, "libname"'``.
+
 version
        **Default Value = 1**.
        Specifies the ABI version of the library, and is used as the major
@@ -991,6 +1001,9 @@ pkgconfig_extra_libs
        using static libraries. Anything added here will be appended to the end
        of the ``pkgconfig --libs`` output.
 
+reason
+       As above.
+
 sources [mandatory]
        As above
 

diff --git a/drivers/meson.build b/drivers/meson.build
index dc47b45..2ed2e95 100644 (file)
--- a/drivers/meson.build
+++ b/drivers/meson.build
@@ -37,6 +37,7 @@ foreach class:dpdk_driver_classes
 
                # set up empty variables used for build
                build = true # set to false to disable, e.g. missing deps
+               reason = '<unknown reason>' # set if build == false to explain
                name = drv
                version = 1
                allow_experimental_apis = false
@@ -58,7 +59,16 @@ foreach class:dpdk_driver_classes
                # pull in driver directory which should assign to each of the above
                subdir(drv_path)
 
-               if build
+               if not build
+                       # some driver directories are placeholders which
+                       # are never built, so we allow suppression of the
+                       # component disable printout in those cases
+                       if reason != ''
+                               dpdk_drvs_disabled += drv_path
+                               set_variable(drv_path.underscorify() +
+                                               '_disable_reason', reason)
+                       endif
+               else
                        class_drivers += name
 
                        dpdk_conf.set(config_flag_fmt.format(name.to_upper()),1)

diff --git a/lib/meson.build b/lib/meson.build
index 9398a3a..5ddf1ca 100644 (file)
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -43,6 +43,7 @@ enabled_libs = [] # used to print summary at the end
 
 foreach l:libraries
        build = true
+       reason = '<unknown reason>' # set if build == false to explain why
        name = l
        version = 1
        allow_experimental_apis = false
@@ -65,7 +66,10 @@ foreach l:libraries
        dir_name = 'librte_' + l
        subdir(dir_name)
 
-       if build
+       if not build
+               dpdk_libs_disabled += name
+               set_variable(name.underscorify() + '_disable_reason', reason)
+       else
                enabled_libs += name
                dpdk_conf.set('RTE_LIBRTE_' + name.to_upper(), 1)
                install_headers(headers)

diff --git a/meson.build b/meson.build
index 76a14cc..c5a3dda 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -20,6 +20,8 @@ dpdk_driver_classes = []
 dpdk_drivers = []
 dpdk_extra_ldflags = []
 dpdk_app_link_libraries = []
+dpdk_libs_disabled = []
+dpdk_drvs_disabled = []
 
 # configure the build, and make sure configs here and in config folder are
 # able to be included in any file. We also store a global array of include dirs
@@ -112,3 +114,16 @@ foreach class:dpdk_driver_classes
        endforeach
 endforeach
 message(output_message + '\n')
+
+output_message = '\n=================\nContent Skipped\n=================\n'
+output_message += '\nlibs:\n\t'
+foreach lib:dpdk_libs_disabled
+       reason = get_variable(lib.underscorify() + '_disable_reason')
+       output_message += lib + ':\t' + reason + '\n\t'
+endforeach
+output_message += '\ndrivers:\n\t'
+foreach drv:dpdk_drvs_disabled
+       reason = get_variable(drv.underscorify() + '_disable_reason')
+       output_message += drv + ':\t' + reason + '\n\t'
+endforeach
+message(output_message + '\n')