feat(codegen): accept pointers to C-struct records in EXTERN signatures

A TYPE record whose fields are all C types, C structs or pointer types to
C structs now crosses the EXTERN "C" boundary through a pointer type.
Records by value are rejected for now, and a pointer to a record with a
non-C field names that field.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/cps/TypeSystem.h b/include/cps/TypeSystem.h
index 5f9af63..1c1e422 100644
--- a/include/cps/TypeSystem.h
+++ b/include/cps/TypeSystem.h
@@ -154,6 +154,13 @@ public:
                       std::string &Err);
     bool sameType(const std::string &Left, const std::string &Right) const;
     const TypeInfo *promoteCScalar(const TypeInfo *Info) const;
+    // A TYPE record (not a CLASS) whose fields are C scalars, C pointers,
+    // C structs or pointer types to C structs. Otherwise Why, if given,
+    // names the first offending field and its type.
+    bool isCStruct(const TypeInfo *Info, std::string *Why = nullptr) const;
+    // Crosses the EXTERN "C" boundary: a non-void C type, a C struct or a
+    // pointer type to one.
+    bool isExternType(const TypeInfo *Info) const;
     const TypeInfo *commonCScalar(const TypeInfo *Left, const TypeInfo *Right) const;
 
     const EnumConstant *lookupEnumConstant(const std::string &Name) const;