[dpdk-dev] [PATCH v4 4/7] build: MinGW-w64 support for Meson

[Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>]

MinGW-w64 linker does not mimic MS linker options, so the build system
must differentiate between linkers on Windows. Use GNU linker options
with GCC and MS linker options with Clang.

MinGW-w64 by default uses MSVCRT stdio, which does not comply to ANSI,
most notably its formatting and string handling functions. MinGW-w64
support for the Universal CRT (UCRT) is ongoing, but the toolchain
provides its own standard-complying implementation of stdio. The latter
is used in the patch to support formatting in DPDK.

Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
---
 config/meson.build | 14 ++++++++++++++
 lib/meson.build    |  8 ++++++--
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/config/meson.build b/config/meson.build
index d3d2370ce..68aeb8470 100644
--- a/config/meson.build
+++ b/config/meson.build
@@ -14,6 +14,10 @@ foreach env:supported_exec_envs
 	set_variable('is_' + env, exec_env == env)
 endforeach
 
+# MS linker requires special treatment.
+# TODO: use cc.get_linker_id() with Meson >= 0.54
+is_ms_linker = is_windows and (cc.get_id() == 'clang')
+
 # set the major version, which might be used by drivers and libraries
 # depending on the configuration options
 pver = meson.project_version().split('.')
@@ -247,6 +251,16 @@ if is_freebsd
 	add_project_arguments('-D__BSD_VISIBLE', language: 'c')
 endif
 
+if is_windows
+	# Minimum supported API is Windows 7.
+	add_project_arguments('-D_WIN32_WINNT=0x0601', language: 'c')
+
+	# Use MinGW-w64 stdio, because DPDK assumes ANSI-compliant formatting.
+	if cc.get_id() == 'gcc'
+		add_project_arguments('-D__USE_MINGW_ANSI_STDIO', language: 'c')
+	endif
+endif
+
 if get_option('b_lto')
 	if cc.has_argument('-ffat-lto-objects')
 		add_project_arguments('-ffat-lto-objects', language: 'c')
diff --git a/lib/meson.build b/lib/meson.build
index 0af3efab2..9c3cc55d5 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -148,12 +148,16 @@ foreach l:libraries
 				command: [map_to_def_cmd, '@INPUT@', '@OUTPUT@'],
 				input: version_map,
 				output: 'rte_@0@_exports.def'.format(name))
-			lk_deps = [version_map, def_file]
-			if is_windows
+
+			if is_ms_linker
 				lk_args = ['-Wl,/def:' + def_file.full_path(),
 					'-Wl,/implib:lib\\' + implib]
 			else
 				lk_args = ['-Wl,--version-script=' + version_map]
+			endif
+
+			lk_deps = [version_map, def_file]
+			if not is_windows
 				# on unix systems check the output of the
 				# experimental syms script, using it as a
 				# dependency of the .so build
-- 
2.25.1