gccrs: proc macro: Add privacy check

Proc macro crates cannot have any public function but proc macros. Proc
macros should be public.

gcc/rust/ChangeLog:

	* checks/errors/privacy/rust-privacy-reporter.cc (PrivacyReporter::go):
	Add visibility verification.

Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>

diff --git a/gcc/rust/checks/errors/privacy/rust-privacy-reporter.cc b/gcc/rust/checks/errors/privacy/rust-privacy-reporter.cc
index 1f1551a7176e58116980574c5d93790c5b1744e2..be357d159b1468da06dd7e7a853521fa6a5f83c9 100644 (file)
--- a/gcc/rust/checks/errors/privacy/rust-privacy-reporter.cc
+++ b/gcc/rust/checks/errors/privacy/rust-privacy-reporter.cc
@@ -17,6 +17,7 @@
 // <http://www.gnu.org/licenses/>.
 
 #include "rust-privacy-reporter.h"
+#include "rust-session-manager.h"
 #include "rust-hir-expr.h"
 #include "rust-hir-stmt.h"
 #include "rust-hir-item.h"
@@ -35,7 +36,44 @@ void
 PrivacyReporter::go (HIR::Crate &crate)
 {
   for (auto &item : crate.get_items ())
-    item->accept_vis (*this);
+    {
+      if (Session::get_instance ().options.is_proc_macro ())
+       {
+         if (item->get_hir_kind () == HIR::Node::BaseKind::VIS_ITEM)
+           {
+             auto &outer_attrs = item->get_outer_attrs ();
+             // Find a proc_macro, proc_macro_derive or proc_macro_attribute
+             // attribute
+             tl::optional<std::string> proc_macro_attribute;
+             for (auto &a : outer_attrs)
+               {
+                 auto &segments = a.get_path ().get_segments ();
+                 if (segments.size () != 1)
+                   break;
+                 auto name = segments.at (0).get_segment_name ();
+                 if (name == "proc_macro" || name == "proc_macro_attribute"
+                     || name == "proc_macro_derive")
+                   proc_macro_attribute = {name};
+               }
+
+             auto vis_item = static_cast<HIR::VisItem *> (item.get ());
+             if (vis_item->get_visibility ().is_public ()
+                 && !proc_macro_attribute.has_value ())
+               rust_error_at (
+                 item->get_locus (),
+                 "%<proc-macro%> crate types currently cannot export any "
+                 "items other than functions tagged with %<#[proc_macro]%>, "
+                 "%<#[proc_macro_derive]%> or %<#[proc_macro_attribute]%>");
+             else if (!vis_item->get_visibility ().is_public ()
+                      && proc_macro_attribute.has_value ())
+               rust_error_at (
+                 item->get_locus (),
+                 "functions tagged with %<#[%s]%> must be %<pub%>",
+                 proc_macro_attribute.value ().c_str ());
+           }
+       }
+      item->accept_vis (*this);
+    }
 }
 
 static bool