Add thread flags to checks if needed. Closes #2106.

mesonbuild/compilers/c.py

@@ -273,9 +273,13 @@ class CCompiler(Compiler):
         for d in dependencies:
             # Add compile flags needed by dependencies
             args += d.get_compile_args()
+            if d.need_threads():
+                args += self.thread_flags()
             if mode == 'link':
                 # Add link flags needed to find dependencies
                 args += d.get_link_args()
+                if d.need_threads():
+                    args += self.thread_link_flags()
         # Select a CRT if needed since we're linking
         if mode == 'link':
             args += self.get_linker_debug_crt_args()

test cases/linuxlike/9 compiler checks with dependencies/meson.build

@@ -29,3 +29,10 @@ int main(int argc, char *argv[]) {
   assert (cc.has_function('deflate', prefix : '#include<zlib.h>', dependencies : zlib, name : 'Test for function in zlib'), 'has_function test failed.')
   assert (cc.links(linkcode, dependencies : zlib, name : 'Test link against zlib'), 'Linking test failed against zlib.')
 endif
+
+assert(cc.has_function('pthread_create',
+    dependencies : dependency('threads'),
+    prefix : '#include <pthread.h>'),
+  'Could not detect pthread_create with a thread dependency.')
+
+