devtools: fix build test config inheritance from env

The variables DPDK_MESON_OPTIONS, PATH, PKG_CONFIG_PATH,
CPPFLAGS, CFLAGS and LDFLAGS can be customized in the config file
loaded by devtools/load-devel-config at each build.
The configuration can be adjusted per target thanks to the value set
in the DPDK_TARGET variable.

PKG_CONFIG_PATH is specific to each target, so it must be empty
before configuring each build from the file according to DPDK_TARGET.
Inheriting a default PKG_CONFIG_PATH for all targets does not make sense
and is prone to confusion.

DPDK_MESON_OPTIONS might take a global initial value from environment
to customize a build test from the shell. Example:
	DPDK_MESON_OPTIONS="b_lto=true"
Some target-specific options can be added in the configuration file:
	DPDK_MESON_OPTIONS="$DPDK_MESON_OPTIONS kernel_dir=$MYKERNEL"

Fixes: 272236741258 ("devtools: load target-specific compilation environment")
Cc: stable@dpdk.org
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>
Tested-by: Jerin Jacob <jerinj@marvell.com>
Acked-by: David Marchand <david.marchand@redhat.com>

diff --git a/devtools/test-meson-builds.sh b/devtools/test-meson-builds.sh
index 0c95d1c..f32b578 100755 (executable)
--- a/devtools/test-meson-builds.sh
+++ b/devtools/test-meson-builds.sh
@@ -38,10 +38,10 @@ else
 fi
 
 default_path=$PATH
-default_pkgpath=$PKG_CONFIG_PATH
 default_cppflags=$CPPFLAGS
 default_cflags=$CFLAGS
 default_ldflags=$LDFLAGS
+default_meson_options=$DPDK_MESON_OPTIONS
 
 check_cc_flags () # <flag to check> <flag2> ...
 {
@@ -52,12 +52,14 @@ check_cc_flags () # <flag to check> <flag2> ...
 load_env () # <target compiler>
 {
        targetcc=$1
+       # reset variables before target-specific config
        export PATH=$default_path
-       export PKG_CONFIG_PATH=$default_pkgpath
+       unset PKG_CONFIG_PATH # global default makes no sense
        export CPPFLAGS=$default_cppflags
        export CFLAGS=$default_cflags
        export LDFLAGS=$default_ldflags
-       unset DPDK_MESON_OPTIONS
+       export DPDK_MESON_OPTIONS=$default_meson_options
+       # set target hint for use in the loaded config file
        if [ -n "$target_override" ] ; then
                DPDK_TARGET=$target_override
        elif command -v $targetcc >/dev/null 2>&1 ; then