[dpdk-dev] [PATCH v2 1/5] build: simplify subdirectory detection for EAL

[Bruce Richardson <bruce.richardson@intel.com>]

Within EAL we had a series of if statements for selecting the EAL directory
to use. Now that the directory names match those of the OS's they are for
we can instead just use a generated subdirectory name, shortening the code.
To avoid strange errors, we still need to check for unsupported OS's, but
do this check up-front in the config meson.build file.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>
---
 config/meson.build         |  7 +++++++
 lib/librte_eal/meson.build | 17 ++---------------
 2 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/config/meson.build b/config/meson.build
index 483139b10..ce6af2595 100644
--- a/config/meson.build
+++ b/config/meson.build
@@ -1,6 +1,13 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright(c) 2017-2019 Intel Corporation
 
+# check the OS is supported, rather than going any further
+supported_exec_envs = ['freebsd', 'linux', 'windows']
+exec_env = host_machine.system()
+if not supported_exec_envs.contains(exec_env)
+	error('unsupported system type "@0@"'.format(exec_env))
+endif
+
 # set the major version, which might be used by drivers and libraries
 # depending on the configuration options
 pver = meson.project_version().split('.')
diff --git a/lib/librte_eal/meson.build b/lib/librte_eal/meson.build
index 1863622c0..fa36b20e0 100644
--- a/lib/librte_eal/meson.build
+++ b/lib/librte_eal/meson.build
@@ -9,21 +9,8 @@ subdir('common') # defines common_sources, common_objs, etc.
 
 # Now do OS/exec-env specific settings, including building kernel modules
 # The <exec-env>/eal/meson.build file should define env_sources, etc.
-if host_machine.system() == 'linux'
-	dpdk_conf.set('RTE_EXEC_ENV_LINUX', 1)
-	subdir('linux/eal')
-
-elif host_machine.system() == 'freebsd'
-	dpdk_conf.set('RTE_EXEC_ENV_FREEBSD', 1)
-	subdir('freebsd/eal')
-
-elif host_machine.system() == 'windows'
-	dpdk_conf.set('RTE_EXEC_ENV_WINDOWS', 1)
-	subdir('windows/eal')
-
-else
-	error('unsupported system type "@0@"'.format(host_machine.system()))
-endif
+dpdk_conf.set('RTE_EXEC_ENV_' + exec_env.to_upper(), 1)
+subdir(exec_env + '/eal')
 
 version = 10  # the version of the EAL API
 allow_experimental_apis = true
-- 
2.20.1