msvc: fix PCH staleness
@@ -2191,6 +2191,13 @@ rule FORTRAN_DEP_HACK%s
elif not self.has_dir_part(d):
d = os.path.join(self.get_target_private_dir(target), d)
element.add_orderdep(d)
+ if compiler.id == 'msvc':
+ # MSVC does not show includes coming from the PCH with '/showIncludes',
+ # thus we must add an implicit dependency to the generated PCH.
+ element.add_dep(pch_dep)
+ else:
+ # All other compilers properly handle includes through the PCH, so only an
+ # orderdep is needed to make the initial build without depfile work.
element.add_orderdep(pch_dep)
# Convert from GCC-style link argument naming to the naming used by the
# current compiler.
