build: fix linker flags on Windows

[ upstream commit da042bc ]

The --export-dynamic linker option is only applicable to ELF.
On Windows, where COFF is used, it causes warnings:

    x86_64-w64-mingw32-ld: warning: --export-dynamic is not supported
    for PE+ targets, did you mean --export-all-symbols? (MinGW)

    LINK : warning LNK4044: unrecognized option '/-export-dynamic';
    ignored (clang)

Don't add --export-dynamic on Windows anywhere.

Fixes: b031e13 ("build: fix plugin load on static build")

Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Acked-by: Ranjit Menon <ranjit.menon@intel.com>

app/meson.build

@@ -26,7 +26,7 @@ lib_execinfo = cc.find_library('execinfo', required: false)
 
 default_cflags = machine_args + ['-DALLOW_EXPERIMENTAL_API']
 default_ldflags = []
-if get_option('default_library') == 'static'
+if get_option('default_library') == 'static' and not is_windows
 	default_ldflags += ['-Wl,--export-dynamic']
 endif
 

buildtools/pkg-config/meson.build

@@ -37,6 +37,10 @@ Use libdpdk.pc instead of this file to query DPDK compile/link arguments''',
 	libraries: ['-Wl,--as-needed'] + dpdk_libraries,
 	libraries_private: dpdk_extra_ldflags)
 
+platform_flags = []
+if not is_windows
+	platform_flags += ['-Wl,--export-dynamic'] # ELF only
+endif
 pkg.generate(name: 'DPDK', # main DPDK pkgconfig file
 	filebase: 'libdpdk',
 	version: meson.project_version(),
@@ -47,7 +51,7 @@ This is required for a number of static inline functions in the public headers.'
 	                  # if libbsd is not enabled, then this is blank
 	libraries_private: ['-Wl,--whole-archive'] +
 			dpdk_drivers + dpdk_static_libraries +
-			['-Wl,--no-whole-archive', '-Wl,--export-dynamic']
+			['-Wl,--no-whole-archive'] + platform_flags
 )
 
 # For static linking with dependencies as shared libraries,

examples/meson.build

@@ -64,7 +64,7 @@ if cc.has_argument('-Wno-format-truncation')
 	default_cflags += '-Wno-format-truncation'
 endif
 default_ldflags = dpdk_extra_ldflags
-if get_option('default_library') == 'static'
+if get_option('default_library') == 'static' and not is_windows
 	default_ldflags += ['-Wl,--export-dynamic']
 endif