[vlc-devel] [PATCH 3.0 16/17] tools: meson: don't use "allow-shlib-undefined" with LLVM if not supported

[Steve Lhomme]

>From https://github.com/mesonbuild/meson/pull/5912

This solves the -lpthread detection issue with libplacebo when compiling with
LLVM for Windows.

(cherry picked from commit f079504ccf7ec7ba0156adf962815dfa7da01aea)
---
 extras/tools/meson-shlib-undefined.patch | 21 +++++++++++++++++++++
 extras/tools/tools.mak                   |  1 +
 2 files changed, 22 insertions(+)
 create mode 100644 extras/tools/meson-shlib-undefined.patch

diff --git a/extras/tools/meson-shlib-undefined.patch b/extras/tools/meson-shlib-undefined.patch
new file mode 100644
index 0000000000..a10f459251
--- /dev/null
+++ b/extras/tools/meson-shlib-undefined.patch
@@ -0,0 +1,21 @@
+--- meson/mesonbuild/linkers.py.shlib	2020-01-31 11:54:36.928015800 +0100
++++ meson/mesonbuild/linkers.py	2020-01-31 11:54:55.088659900 +0100
+@@ -659,8 +659,17 @@ class LLVMDynamicLinker(GnuLikeDynamicLi
+     This is only the posix-like linker.
+     """
+ 
+-    pass
++    def __init__(self, *args, **kwargs):
++        super().__init__(*args, **kwargs)
+ 
++        # Some targets don't seem to support this argument (windows, wasm, ...)
++        _, _, e = mesonlib.Popen_safe(self.exelist + self._apply_prefix('--allow-shlib-undefined'))
++        self.has_allow_shlib_undefined = not ('unknown argument: --allow-shlib-undefined' in e)
++
++    def get_allow_undefined_args(self) -> T.List[str]:
++        if self.has_allow_shlib_undefined:
++            return self._apply_prefix('--allow-shlib-undefined')
++        return []
+ 
+ class CcrxDynamicLinker(DynamicLinker):
+ 
diff --git a/extras/tools/tools.mak b/extras/tools/tools.mak
index c4575faf24..dd11038fac 100644
--- a/extras/tools/tools.mak
+++ b/extras/tools/tools.mak
@@ -363,6 +363,7 @@ meson-$(MESON_VERSION).tar.gz:
 
 meson: meson-$(MESON_VERSION).tar.gz
 	$(UNPACK)
+	$(APPLY) $(TOOLS)/meson-shlib-undefined.patch
 	$(MOVE)
 
 .meson: meson
-- 
2.17.1