visualstudio: do not query underscore define with MSVC

MSVC does not has the builtin define to check for the symbol
prefix, so do not try to query it at all, to save some time.

1 files changed, 17 insertions, 0 deletions

diff --git a/mesonbuild/compilers/mixins/visualstudio.py b/mesonbuild/compilers/mixins/visualstudio.py
index 5118e41..2f26453 100644
--- a/mesonbuild/compilers/mixins/visualstudio.py
+++ b/mesonbuild/compilers/mixins/visualstudio.py
@@ -383,6 +383,23 @@ class VisualStudioLikeCompiler(Compiler, metaclass=abc.ABCMeta):
     def get_argument_syntax(self) -> str:
         return 'msvc'
 
+    def symbols_have_underscore_prefix(self, env: 'Environment') -> bool:
+        '''
+        Check if the compiler prefixes an underscore to global C symbols.
+
+        This overrides the Clike method, as for MSVC checking the
+        underscore prefix based on the compiler define never works,
+        so do not even try.
+        '''
+        # Try to consult a hardcoded list of cases we know
+        # absolutely have an underscore prefix
+        result = self._symbols_have_underscore_prefix_list(env)
+        if result is not None:
+            return result
+
+        # As a last resort, try search in a compiled binary
+        return self._symbols_have_underscore_prefix_searchbin(env)
+
 
 class MSVCCompiler(VisualStudioLikeCompiler):