build: fix linker warnings with clang on Windows

Clang on Windows doesn't use pthread for now, while MinGW does. Removing
`-pthread` option with MS linker fixes the following warning:

    clang: warning: argument unused during compilation: '-pthread'
        [-Wunused-command-line-argument]

Option `--no-as-needed` is meaningless for PE output. Disabling it on
Windows fixes the following warning:

    LINK : warning LNK4044: unrecognized option '/-no-as-needed'; ignored

Fixes: 98edcbb5a ("eal/windows: introduce Windows support")

Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Tested-by: William Tu <u9012063@gmail.com>
Tested-by: Pallavi Kadam <pallavi.kadam@intel.com>
Acked-by: Pallavi Kadam <pallavi.kadam@intel.com>

diff --git a/config/meson.build b/config/meson.build
index 68aeb84..abedd76 100644 (file)
--- a/config/meson.build
+++ b/config/meson.build
@@ -112,11 +112,15 @@ dpdk_conf.set('RTE_TOOLCHAIN_' + toolchain.to_upper(), 1)
 
 dpdk_conf.set('RTE_ARCH_64', cc.sizeof('void *') == 8)
 
-add_project_link_arguments('-Wl,--no-as-needed', language: 'c')
+if not is_windows
+       add_project_link_arguments('-Wl,--no-as-needed', language: 'c')
+endif
 
-# use pthreads
-add_project_link_arguments('-pthread', language: 'c')
-dpdk_extra_ldflags += '-pthread'
+# use pthreads if available for the platform
+if not is_ms_linker
+       add_project_link_arguments('-pthread', language: 'c')
+       dpdk_extra_ldflags += '-pthread'
+endif
 
 # on some OS, maths functions are in a separate library
 if cc.find_library('m', required : false).found()