Modular Codegen: Add/use a bit in serialized function definitions to track whether they are the subject of modular codegen

Some decls are created not where they are written, but in other module
files/users (implicit special members and function template implicit
specializations). To correctly identify them, use a bit next to the definition
to track the modular codegen property.

Discussed whether the module file bit could be omitted in favor of
reconstituting from the modular codegen decls list - best guess today is that
the efficiency improvement of not having to deserialize the whole list whenever
any function is queried by a module user is worth it for the small size
increase of this redundant (list + bit-on-def) representation.

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D29901

llvm-svn: 299982

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/test/Modules/Inputs/codegen-nodep/foo.modulemap b/clang/test/Modules/Inputs/codegen-nodep/foo.modulemap
new file mode 100644
index 00000000000..2e095d2794c
--- /dev/null
+++ b/clang/test/Modules/Inputs/codegen-nodep/foo.modulemap
@@ -0,0 +1 @@
+module foo { header "foo.h" }