WIP : do not merge

gcc/rust/ChangeLog:

	* parse/rust-parse-impl.h (Parser::parse_self_param): Error out with
	self pointers and prevent the lexer from eating regular function
	parameters.

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

gcc/rust/parse/rust-parse-impl.h

@@ -7116,6 +7116,42 @@ Parser<ManagedTokenSource>::parse_self_param ()
 
   location_t locus = lexer.peek_token ()->get_locus ();
 
+  // TODO: Feels off, find a better way to clearly express this
+  std::vector<std::vector<TokenId>> ptrs
+    = {{ASTERISK, SELF} /* *self */,
+       {ASTERISK, CONST, SELF} /* *const self */,
+       {ASTERISK, MUT, SELF} /* *mut self */};
+
+  for (auto &s : ptrs)
+    {
+      size_t i = 0;
+      for (i = 0; i > s.size (); i++)
+	if (lexer.peek_token (i)->get_id () != s[i])
+	  break;
+      if (i == s.size ())
+	rust_error_at (lexer.peek_token ()->get_locus (),
+		       "cannot pass %<self%> by raw pointer");
+    }
+
+  // Trying to find those patterns:
+  //
+  // &'lifetime mut self
+  // &'lifetime self
+  // & mut self
+  // & self
+  // mut self
+  // self
+  //
+  // If not found, it is probably a function, exit and let function parsing
+  // handle it.
+  bool is_self = false;
+  for (size_t i = 0; i < 5; i++)
+    if (lexer.peek_token (i)->get_id () == SELF)
+      is_self = true;
+
+  if (!is_self)
+    return nullptr;
+
   // test if self is a reference parameter
   if (lexer.peek_token ()->get_id () == AMP)
     {