build/pkg-config: improve static linking flags

[dpdk.git] / buildtools / pkg-config / meson.build

diff --git a/buildtools/pkg-config/meson.build b/buildtools/pkg-config/meson.build
index 85d5997..dacc5db 100644 (file)
--- a/buildtools/pkg-config/meson.build
+++ b/buildtools/pkg-config/meson.build
@@ -1,26 +1,50 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright(c) 2020 Intel Corporation
 
-# for static builds, include the drivers as libs and we need to "whole-archive"
-# them.
-dpdk_drivers = ['-Wl,--whole-archive'] + dpdk_drivers + ['-Wl,--no-whole-archive']
-
 pkg = import('pkgconfig')
 pkg_extra_cflags = ['-include', 'rte_config.h'] + machine_args
 if is_freebsd
        pkg_extra_cflags += ['-D__BSD_VISIBLE']
 endif
-pkg.generate(name: meson.project_name(),
-       filebase: 'lib' + meson.project_name().to_lower(),
+
+# When calling pkg-config --static --libs, pkg-config will always output the
+# regular libs first, and then the extra libs from Libs.private field,
+# since the assumption is that those are additional dependencies for building
+# statically that the .a files depend upon. The output order of .pc fields is:
+#   Libs   Libs.private   Requires   Requires.private
+# The fields Requires* are for package names.
+# The flags of the DPDK libraries must be defined in Libs* fields.
+# However, the DPDK drivers are linked only in static builds (Libs.private),
+# and those need to come *before* the regular libraries (Libs field).
+# This requirement is satisfied by moving the regular libs in a separate file
+# included in the field Requires (after Libs.private).
+# Another requirement is to allow linking dependencies as shared libraries,
+# while linking static DPDK libraries and drivers. It is satisfied by
+# listing the static files in Libs.private with the explicit syntax -l:libfoo.a.
+
+pkg.generate(name: 'dpdk-libs',
+       filebase: 'libdpdk-libs',
+       description: '''Internal-only DPDK pkgconfig file. Not for direct use.
+Use libdpdk.pc instead of this file to query DPDK compile/link arguments''',
        version: meson.project_version(),
+       subdirs: [get_option('include_subdir_arch'), '.'],
+       extra_cflags: pkg_extra_cflags,
        libraries: dpdk_libraries,
-       libraries_private: dpdk_drivers + dpdk_static_libraries +
-                       ['-Wl,-Bdynamic'] + dpdk_extra_ldflags,
-       requires: libbsd, # apps using rte_string_fns.h may need this if enabled
-                         # if libbsd is not enabled, then this is blank
+       libraries_private: dpdk_extra_ldflags)
+
+pkg.generate(name: 'DPDK', # main DPDK pkgconfig file
+       filebase: 'libdpdk',
+       version: meson.project_version(),
        description: '''The Data Plane Development Kit (DPDK).
 Note that CFLAGS might contain an -march flag higher than typical baseline.
 This is required for a number of static inline functions in the public headers.''',
-       subdirs: [get_option('include_subdir_arch'), '.'],
-       extra_cflags: pkg_extra_cflags
+       requires: ['libdpdk-libs', libbsd], # may need libbsd for string funcs
+                         # if libbsd is not enabled, then this is blank
+       libraries_private: ['-Wl,--whole-archive'] +
+                       dpdk_drivers + dpdk_static_libraries +
+                       ['-Wl,--no-whole-archive']
 )
+
+# For static linking with dependencies as shared libraries,
+# the internal static libraries must be flagged explicitly.
+run_command(py3, 'set-static-linker-flags.py', check: true)