linkers: add gen_vs_module_defs_args

.def files are a linker concept, and they should not be shoehorned
into the Compiler.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/mesonbuild/linkers/linkers.py b/mesonbuild/linkers/linkers.py
index 1d61f4a4b..8f9738283 100644
--- a/mesonbuild/linkers/linkers.py
+++ b/mesonbuild/linkers/linkers.py
@@ -258,6 +258,9 @@ class DynamicLinker(metaclass=abc.ABCMeta):
     def get_coverage_args(self) -> T.List[str]:
         raise EnvironmentException(f"Linker {self.id} doesn't implement coverage data generation.")
 
+    def gen_vs_module_defs_args(self, defsfile: str) -> T.List[str]:
+        return []
+
     @abc.abstractmethod
     def get_search_args(self, dirname: str) -> T.List[str]:
         pass
@@ -696,6 +699,15 @@ class GnuLikeDynamicLinkerMixin(DynamicLinkerBase):
     def get_coverage_args(self) -> T.List[str]:
         return ['--coverage']
 
+    def gen_vs_module_defs_args(self, defsfile: str) -> T.List[str]:
+        # On Windows targets, .def files may be specified on the linker command
+        # line like an object file.
+        m = self.environment.machines[self.for_machine]
+        if m.is_windows() or m.is_cygwin():
+            return [defsfile]
+        # For other targets, discard the .def file.
+        return []
+
     def export_dynamic_args(self) -> T.List[str]:
         m = self.environment.machines[self.for_machine]
         if m.is_windows() or m.is_cygwin():
@@ -1448,6 +1460,11 @@ class VisualStudioLikeLinkerMixin(DynamicLinkerBase):
     def get_allow_undefined_args(self) -> T.List[str]:
         return []
 
+    def gen_vs_module_defs_args(self, defsfile: str) -> T.List[str]:
+        # With MSVC, DLLs only export symbols that are explicitly exported,
+        # so if a module defs file is specified, we use that to export symbols
+        return ['/DEF:' + defsfile]
+
     def get_soname_args(self, prefix: str, shlib_name: str, suffix: str,
                         soversion: str, darwin_versions: T.Tuple[str, str]
                         ) -> T.List[str]: