From: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>
Date: Tue, 18 Jul 2023 12:38:58 +0000 (+0200)
Subject: gccrs: proc macro: Add help message to malformed derive
X-Git-Tag: basepoints/gcc-15~2332
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9a99feab7cbc2dcb01c3af99dca4c2a4403d83b1;p=thirdparty%2Fgcc.git

gccrs: proc macro: Add help message to malformed derive

Add an help message in case of malformed proc_macro_derive declaration.

gcc/rust/ChangeLog:

	* util/rust-attributes.cc (AttributeChecker::visit): Add help
	message.

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

diff --git a/gcc/rust/util/rust-attributes.cc b/gcc/rust/util/rust-attributes.cc
index c8451def94eb..3ee7f2b6f0c5 100644
--- a/gcc/rust/util/rust-attributes.cc
+++ b/gcc/rust/util/rust-attributes.cc
@@ -565,6 +565,10 @@ AttributeChecker::visit (AST::Function &fun)
 	    {
 	      rust_error_at (attribute.get_locus (),
 			     "malformed %<%s%> attribute input", name);
+	      rust_inform (
+		attribute.get_locus (),
+		"must be of the form: %<#[proc_macro_derive(TraitName, "
+		"/*opt*/ attributes(name1, name2, ...))]%>");
 	    }
 	  check_crate_type (name, attribute);
 	}