[gcc r15-8589] gccrs: lower: Correctly lower parenthesized types

[Arthur Cohen]

https://gcc.gnu.org/g:cd8547f85e53b42eff5a7c7572b466c023c75daf

commit r15-8589-gcd8547f85e53b42eff5a7c7572b466c023c75daf
Author: Arthur Cohen <arthur.cohen@embecosm.com>
Date:   Wed Dec 25 17:55:09 2024 +0000

    gccrs: lower: Correctly lower parenthesized types
    
    This is useful for handling multiple trait bounds, and required for better handling of auto traits.
    
    gcc/rust/ChangeLog:
    
            * hir/rust-ast-lower-type.cc (ASTLoweringType::visit): Add implementation for
            ParenthesizedType.
            * hir/rust-ast-lower-type.h: Declare that new visitor.
    
    gcc/testsuite/ChangeLog:
    
            * rust/compile/auto_traits1.rs: New test.

Diff:
---
 gcc/rust/hir/rust-ast-lower-type.cc        | 19 +++++++++++++++++++
 gcc/rust/hir/rust-ast-lower-type.h         |  2 ++
 gcc/testsuite/rust/compile/auto_traits1.rs | 27 +++++++++++++++++++++++++++
 3 files changed, 48 insertions(+)

diff --git a/gcc/rust/hir/rust-ast-lower-type.cc b/gcc/rust/hir/rust-ast-lower-type.cc
index df06e48b801d..d1f95edc3456 100644
--- a/gcc/rust/hir/rust-ast-lower-type.cc
+++ b/gcc/rust/hir/rust-ast-lower-type.cc
@@ -19,6 +19,7 @@
 #include "rust-ast-lower-type.h"
 #include "rust-hir-map.h"
 #include "rust-hir-path.h"
+#include "rust-hir-type.h"
 #include "rust-path.h"
 #include "rust-pattern.h"
 
@@ -471,6 +472,24 @@ ASTLoweringType::visit (AST::TraitObjectType &type)
 					 type.get_locus (), type.is_dyn ());
 }
 
+void
+ASTLoweringType::visit (AST::ParenthesisedType &type)
+{
+  auto *inner = ASTLoweringType::translate (*type.get_type_in_parens (),
+					    default_to_static_lifetime);
+
+  auto crate_num = mappings.get_current_crate ();
+  Analysis::NodeMapping mapping (crate_num, type.get_node_id (),
+				 mappings.get_next_hir_id (crate_num),
+				 mappings.get_next_localdef_id (crate_num));
+
+  // FIXME: Do we actually need to know if a type is parenthesized in the HIR?
+  // or can we just use the type in parens?
+  translated
+    = new HIR::ParenthesisedType (mapping, std::unique_ptr<HIR::Type> (inner),
+				  type.get_locus ());
+}
+
 HIR::GenericParam *
 ASTLowerGenericParam::translate (AST::GenericParam &param)
 {
diff --git a/gcc/rust/hir/rust-ast-lower-type.h b/gcc/rust/hir/rust-ast-lower-type.h
index 0429e3fcf986..26ca8684083c 100644
--- a/gcc/rust/hir/rust-ast-lower-type.h
+++ b/gcc/rust/hir/rust-ast-lower-type.h
@@ -22,6 +22,7 @@
 #include "rust-ast-lower-base.h"
 #include "rust-ast-lower-expr.h"
 #include "rust-hir-path.h"
+#include "rust-type.h"
 
 namespace Rust {
 namespace HIR {
@@ -83,6 +84,7 @@ public:
   void visit (AST::NeverType &type) override;
   void visit (AST::TraitObjectTypeOneBound &type) override;
   void visit (AST::TraitObjectType &type) override;
+  void visit (AST::ParenthesisedType &type) override;
 
 private:
   ASTLoweringType (bool default_to_static_lifetime)
diff --git a/gcc/testsuite/rust/compile/auto_traits1.rs b/gcc/testsuite/rust/compile/auto_traits1.rs
new file mode 100644
index 000000000000..192052d48151
--- /dev/null
+++ b/gcc/testsuite/rust/compile/auto_traits1.rs
@@ -0,0 +1,27 @@
+// { dg-additional-options "-frust-compile-until=typecheck" }
+
+#![feature(optin_builtin_traits)]
+
+pub unsafe auto trait Send {}
+#[lang = "sync"]
+pub unsafe auto trait Sync {}
+
+trait A {
+    fn a_method(&self) {}
+}
+
+fn foo(a: &(dyn A + Send + Sync)) {
+    a.a_method();
+}
+
+struct S;
+
+impl A for S {
+    fn a_method(&self) {}
+}
+
+fn main() {
+    let s = S;
+
+    foo(&s);
+}