meson: fix MSVC support

Regression from commit a5f2c45528032ed20c33e0f8cd2c163a800a0017. It is
not possible to unconditionally add the asm sources, since not all
compilers understand the .s file extension.

Specifically for meson, only compilers inheriting from the GNU mixin
will allow a .s file at configure time.

zstd doesn't support asm for MSVC for the same basic reason; if/when
Windows asm support is added, it would involve preprocessing with nasm,
most likely.

diff --git a/build/meson/lib/meson.build b/build/meson/lib/meson.build
index 1f4f8c25db3e95aa683816509a163731054793a2..2a8c55fbf5294020584caa9a6d107fc547aae45e 100644 (file)
--- a/build/meson/lib/meson.build
+++ b/build/meson/lib/meson.build
@@ -37,7 +37,6 @@ libzstd_sources = [join_paths(zstd_rootdir, 'lib/common/entropy_common.c'),
   join_paths(zstd_rootdir, 'lib/compress/zstd_opt.c'),
   join_paths(zstd_rootdir, 'lib/compress/zstd_ldm.c'),
   join_paths(zstd_rootdir, 'lib/decompress/huf_decompress.c'),
-  join_paths(zstd_rootdir, 'lib/decompress/huf_decompress_amd64.S'),
   join_paths(zstd_rootdir, 'lib/decompress/zstd_decompress.c'),
   join_paths(zstd_rootdir, 'lib/decompress/zstd_decompress_block.c'),
   join_paths(zstd_rootdir, 'lib/decompress/zstd_ddict.c'),
@@ -46,6 +45,12 @@ libzstd_sources = [join_paths(zstd_rootdir, 'lib/common/entropy_common.c'),
   join_paths(zstd_rootdir, 'lib/dictBuilder/divsufsort.c'),
   join_paths(zstd_rootdir, 'lib/dictBuilder/zdict.c')]
 
+# really we need anything that defines __GNUC__ as that is what ZSTD_ASM_SUPPORTED is gated on
+# but these are the two compilers that are supported in tree and actually handle this correctly
+if [compiler_gcc, compiler_clang].contains(cc_id)
+  libzstd_sources += join_paths(zstd_rootdir, 'lib/decompress/huf_decompress_amd64.S')
+endif
+
 # Explicit define legacy support
 add_project_arguments('-DZSTD_LEGACY_SUPPORT=@0@'.format(legacy_level),
   language: 'c')