[C++20] [Modules] Attach implicitly declared allocation funcitons to

global module fragment

[basic.stc.dynamic.general]p2 says:
> The library provides default definitions for the global allocation
> and deallocation functions. Some global allocation and
> deallocation
> functions are replaceable ([new.delete]); these are attached to
> the global module ([module.unit]).

But we didn't take this before and the implicitly generated functions
will live in the module purview if we're compiling a module unit. This
is bad since the owning module will affect the linkage of the
declarations. This patch addresses this.

Closes https://github.com/llvm/llvm-project/issues/58560

1 files changed, 3 insertions, 1 deletions

diff --git a/clang/lib/Basic/Module.cpp b/clang/lib/Basic/Module.cpp
index 9a58fae..2f30fa0 100644
--- a/clang/lib/Basic/Module.cpp
+++ b/clang/lib/Basic/Module.cpp
@@ -633,7 +633,9 @@ LLVM_DUMP_METHOD void Module::dump() const {
 
 void VisibleModuleSet::setVisible(Module *M, SourceLocation Loc,
                                   VisibleCallback Vis, ConflictCallback Cb) {
-  assert(Loc.isValid() && "setVisible expects a valid import location");
+  // We can't import a global module fragment so the location can be invalid.
+  assert((M->isGlobalModule() || Loc.isValid()) &&
+         "setVisible expects a valid import location");
   if (isVisible(M))
     return;