[PATCH v6 3/4] c++modules: report imported CMI files as dependencies

[Ben Boeckel <ben.boeckel@kitware.com>]

They affect the build, so report them via `-MF` mechanisms.

gcc/cp/

	* module.cc (do_import): Report imported CMI files as
	dependencies.

Signed-off-by: Ben Boeckel <ben.boeckel@kitware.com>
---
 gcc/cp/module.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index c80f139eb82..e88ce0a1818 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -18966,6 +18966,9 @@ module_state::do_import (cpp_reader *reader, bool outermost)
       dump () && dump ("CMI is %s", file);
       if (note_module_cmi_yes || inform_cmi_p)
 	inform (loc, "reading CMI %qs", file);
+      /* Add the CMI file to the dependency tracking. */
+      if (cpp_get_deps (reader))
+	deps_add_dep (cpp_get_deps (reader), file);
       fd = open (file, O_RDONLY | O_CLOEXEC | O_BINARY);
       e = errno;
     }
-- 
2.40.1