gccrs: fix inner attr derive doesn't show error

gcc/rust/ChangeLog:

	* ast/rust-ast.cc (Attribute::is_derive):
	Change string derive to its definition.
	* util/rust-attribute-values.h:
	Add attribute definition derive.
	* util/rust-attributes.cc (AttributeChecker::visit):
	Add method check_inner_attributes.
	(AttributeChecker::check_inner_attributes):
	Check if there is a bad inner attribute.
	* util/rust-attributes.h:
	Add method check_inner_attributes in .h.

gcc/testsuite/ChangeLog:

	* rust/compile/issue-4212.rs: New test.

Signed-off-by: Lucas Ly Ba <lucas.ly-ba@outlook.fr>

Author: Lucas Ly Ba

gcc/rust/ast/rust-ast.cc

@@ -248,7 +248,7 @@ Attribute::as_string () const
 bool
 Attribute::is_derive () const
 {
-  return has_attr_input () && get_path () == "derive";
+  return has_attr_input () && get_path () == Values::Attributes::DERIVE;
 }
 
 /**

gcc/rust/util/rust-attribute-values.h

@@ -49,6 +49,8 @@ class Attributes
   static constexpr auto &PROC_MACRO_DERIVE = "proc_macro_derive";
   static constexpr auto &PROC_MACRO_ATTRIBUTE = "proc_macro_attribute";
 
+  static constexpr auto &DERIVE = "derive";
+
   static constexpr auto &TARGET_FEATURE = "target_feature";
   // From now on, these are reserved by the compiler and gated through
   // #![feature(rustc_attrs)]

gcc/rust/util/rust-attributes.cc

@@ -90,6 +90,8 @@ static const BuiltinAttrDefinition __definitions[]
      {Attrs::PROC_MACRO, EXPANSION},
      {Attrs::PROC_MACRO_DERIVE, EXPANSION},
      {Attrs::PROC_MACRO_ATTRIBUTE, EXPANSION},
+
+     {Attrs::DERIVE, EXPANSION},
      // FIXME: This is not implemented yet, see
      // https://github.com/Rust-GCC/gccrs/issues/1475
      {Attrs::TARGET_FEATURE, CODE_GENERATION},
@@ -170,6 +172,7 @@ AttributeChecker::go (AST::Crate &crate)
 void
 AttributeChecker::visit (AST::Crate &crate)
 {
+  check_inner_attributes (crate.get_inner_attrs ());
   check_attributes (crate.get_inner_attrs ());
 
   for (auto &item : crate.items)
@@ -353,6 +356,15 @@ AttributeChecker::check_attribute (const AST::Attribute &attribute)
     check_doc_attribute (attribute);
 }
 
+void
+AttributeChecker::check_inner_attributes (const AST::AttrVec &attributes)
+{
+  for (auto &attr : attributes)
+    if (attr.is_derive ())
+      rust_error_at (attr.get_locus (),
+		     "derive attribute cannot be used at crate level");
+}
+
 void
 AttributeChecker::check_attributes (const AST::AttrVec &attributes)
 {

gcc/rust/util/rust-attributes.h

@@ -106,6 +106,8 @@ class AttributeChecker : public AST::DefaultASTVisitor
   void check_attribute (const AST::Attribute &attribute);
 
   /* Check the validity of all given attributes */
+
+  void check_inner_attributes (const AST::AttrVec &attributes);
   void check_attributes (const AST::AttrVec &attributes);
 
   // rust-ast.h

gcc/testsuite/rust/compile/issue-4212.rs

@@ -0,0 +1,5 @@
+#![derive(PartialOrd, PartialEq)]
+// { dg-error "derive attribute cannot be used at crate level" "" { target *-*-* } .-1 }
+pub fn check_ge(a: i32, b: i32) -> bool {
+    a >= b
+}