[gccrs COMMIT] gccrs: Fix bad derive of Ord to use Self instead of raw type-name

[gerris.rs@gmail.com]

From: Philip Herron <herron.philip@googlemail.com>

The raw type name doesnt capture the generic state of the impl but Self
does.

Fixes Rust-GCC/gccrs#4879

gcc/rust/ChangeLog:

	* expand/rust-derive-ord.cc (DeriveOrd::cmp_fn): use Self

gcc/testsuite/ChangeLog:

	* rust/compile/issue-4879.rs: New test.

Signed-off-by: Philip Herron <herron.philip@googlemail.com>
---
This change was merged into the gccrs repository and is posted here for
upstream visibility and potential drive-by review, as requested by GCC
release managers.
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Commit on github: https://github.com/Rust-GCC/gccrs/commit/c88ea29f9075ba0b80925f1e1abf3ec84338f3d9

The commit has been mentioned in the following issue(s):
 - Rust-GCC/gccrs#4879: https://github.com/Rust-GCC/gccrs/issues/4879

The commit has been mentioned in the following pull-request(s):
 - https://github.com/Rust-GCC/gccrs/pull/4880

 gcc/rust/expand/rust-derive-ord.cc       | 13 +++--
 gcc/testsuite/rust/compile/issue-4879.rs | 65 ++++++++++++++++++++++++
 2 files changed, 73 insertions(+), 5 deletions(-)
 create mode 100644 gcc/testsuite/rust/compile/issue-4879.rs

diff --git a/gcc/rust/expand/rust-derive-ord.cc b/gcc/rust/expand/rust-derive-ord.cc
index aae7f8414..7960d2978 100644
--- a/gcc/rust/expand/rust-derive-ord.cc
+++ b/gcc/rust/expand/rust-derive-ord.cc
@@ -100,11 +100,14 @@ DeriveOrd::cmp_fn (std::unique_ptr<BlockExpr> &&block, Identifier type_name)
     }
 
   // &self, other: &Self
-  auto params = vec (
-    builder.self_ref_param (),
-    builder.function_param (builder.identifier_pattern ("other"),
-			    builder.reference_type (ptrify (
-			      builder.type_path (type_name.as_string ())))));
+  //
+  // this must be Self for a generic type Wrapping<T> the bare struct name has
+  // no type arguments
+  auto params
+    = vec (builder.self_ref_param (),
+	   builder.function_param (builder.identifier_pattern ("other"),
+				   builder.reference_type (
+				     ptrify (builder.type_path ("Self")))));
 
   auto function_name = fn (ordering);
 
diff --git a/gcc/testsuite/rust/compile/issue-4879.rs b/gcc/testsuite/rust/compile/issue-4879.rs
new file mode 100644
index 000000000..e2e8ac107
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-4879.rs
@@ -0,0 +1,65 @@
+#![feature(no_core, lang_items)]
+#![no_core]
+
+#[lang = "sized"]
+pub trait Sized {}
+
+#[lang = "structural_peq"]
+pub trait StructuralPartialEq {}
+
+#[lang = "structural_teq"]
+pub trait StructuralEq {}
+
+#[lang = "phantom_data"]
+pub struct PhantomData<T: ?Sized>;
+
+pub mod option {
+    pub enum Option<T> {
+        #[lang = "None"]
+        None,
+        #[lang = "Some"]
+        Some(T),
+    }
+}
+
+pub use option::Option;
+
+pub mod cmp {
+    use crate::Sized;
+
+    #[lang = "eq"]
+    pub trait PartialEq<Rhs: ?Sized = Self> {
+        fn eq(&self, other: &Rhs) -> bool;
+        fn ne(&self, other: &Rhs) -> bool {
+            !self.eq(other)
+        }
+    }
+
+    pub trait Eq: PartialEq<Self> {
+        fn assert_receiver_is_total_eq(&self) {}
+    }
+
+    pub enum Ordering {
+        Less = -1,
+        Equal = 0,
+        Greater = 1,
+    }
+
+    #[lang = "partial_ord"]
+    pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
+        fn partial_cmp(&self, other: &Rhs) -> crate::Option<Ordering>;
+    }
+
+    pub trait Ord: Eq + PartialOrd<Self> {
+        fn cmp(&self, other: &Self) -> Ordering;
+    }
+}
+
+use cmp::{Eq, Ord, PartialEq, PartialOrd};
+
+#[derive(PartialEq, PartialOrd, Eq, Ord)]
+pub struct Wrapping<T>(pub T);
+
+fn main() -> i32 {
+    0
+}

base-commit: eaf49ee2856dfa1a025af1985941df0d73775ba3
-- 
2.55.0