seen_decls: FxHashMap<Symbol, HirId>
Map of function symbol name to the first-seen hir id for that symbol name.. If seen_decls contains an entry for key K, it means a symbol with name K has been seen by this lint and the symbol should be reported as a clashing declaration.
Insert a new foreign item into the seen set. If a symbol with the same name already exists for the item, return its HirId without updating the set.
Get the name of the symbol that’s linked against for a given extern declaration. That is, the name specified in a #[link_name = …] attribute if one was specified, else, just the symbol’s name.
Checks whether two types are structurally the same enough that the declarations shouldn’t clash. We need this so we don’t emit a lint when two modules both declare an extern struct, with the same members (as the declarations shouldn’t clash).
Returns the argument unchanged.
Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain
repr(...) attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.
Size: 32 bytes