has_multi_link_arguments: Some compilers needs -Wl,--fatal-warnings

ld does not treat wrong -z options as fatal by default.

mesonbuild/compilers/c.py

@@ -59,6 +59,9 @@ class CCompiler(Compiler):
         else:
             self.exe_wrapper = exe_wrapper
 
+        # Set to None until we actually need to check this
+        self.has_fatal_warnings_link_arg = None
+
     def needs_static_linker(self):
         return True # When compiling static libraries, so yes.
 
@@ -871,6 +874,17 @@ class CCompiler(Compiler):
         return self.has_arguments(args, env, code, mode='compile')
 
     def has_multi_link_arguments(self, args, env):
+        # First time we check for link flags we need to first check if we have
+        # --fatal-warnings, otherwise some linker checks could give some
+        # false positive.
+        fatal_warnings_args = ['-Wl,--fatal-warnings']
+        if self.has_fatal_warnings_link_arg is None:
+            self.has_fatal_warnings_link_arg = False
+            self.has_fatal_warnings_link_arg = self.has_multi_link_arguments(fatal_warnings_args, env)
+
+        if self.has_fatal_warnings_link_arg:
+            args = fatal_warnings_args + args
+
         args = self.linker_to_compiler_args(args)
         code = 'int main(int argc, char **argv) { return 0; }'
         return self.has_arguments(args, env, code, mode='link')

test cases/common/191 has link arg/meson.build

@@ -40,3 +40,5 @@ assert(l2.length() == 0, 'First supported did not return empty array.')
 assert(not cc.has_multi_link_arguments([isnt_arg, is_arg]), 'Arg that should be broken is not.')
 assert(cc.has_multi_link_arguments(is_arg), 'Arg that should have worked does not work.')
 assert(cc.has_multi_link_arguments([useless, is_arg]), 'Arg that should have worked does not work.')
+
+assert(not cc.has_link_argument('-Wl,-z,nodelete42'), 'Did not detect wrong -z linker argument')