https://gcc.gnu.org/g:499a70699bcaff13998fa8eb6136c15dfa0b7f41
commit r16-2958-g499a70699bcaff13998fa8eb6136c15dfa0b7f41
Author: Arthur Cohen <arthur.co...@embecosm.com>
Date: Tue Jul 22 13:30:11 2025 +0200
gccrs: desugar: Handle try-blocks
gcc/rust/ChangeLog:
* Make-lang.in: Compile it.
* ast/rust-expression-yeast.cc (ExpressionYeast::dispatch):
Dispatch to try-block
desugar.
* ast/rust-desugar-try-block.cc: New file.
* ast/rust-desugar-try-block.h: New file.
gcc/testsuite/ChangeLog:
* rust/compile/try_block1.rs: New test.
Diff:
---
gcc/rust/Make-lang.in | 2 +-
gcc/rust/ast/rust-desugar-try-block.cc | 60 +++++++++++++++++++++
gcc/rust/ast/rust-desugar-try-block.h | 42 +++++++++++++++
gcc/rust/ast/rust-expression-yeast.cc | 4 ++
gcc/testsuite/rust/compile/try_block1.rs | 89 ++++++++++++++++++++++++++++++++
5 files changed, 196 insertions(+), 1 deletion(-)
diff --git a/gcc/rust/Make-lang.in b/gcc/rust/Make-lang.in
index 506435d20038..12c9a427143f 100644
--- a/gcc/rust/Make-lang.in
+++ b/gcc/rust/Make-lang.in
@@ -246,7 +246,7 @@ GRS_OBJS = \
rust/rust-desugar-for-loops.o \
rust/rust-desugar-question-mark.o \
rust/rust-desugar-apit.o \
- # rust/rust-desugar-try-block.o \
+ rust/rust-desugar-try-block.o \
$(END)
# removed object files from here
diff --git a/gcc/rust/ast/rust-desugar-try-block.cc
b/gcc/rust/ast/rust-desugar-try-block.cc
new file mode 100644
index 000000000000..cd03350e98b8
--- /dev/null
+++ b/gcc/rust/ast/rust-desugar-try-block.cc
@@ -0,0 +1,60 @@
+// Copyright (C) 2025 Free Software Foundation, Inc.
+
+// This file is part of GCC.
+
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#include "rust-desugar-try-block.h"
+#include "rust-ast-builder.h"
+#include "rust-expr.h"
+
+namespace Rust {
+namespace AST {
+
+DesugarTryBlock::DesugarTryBlock () {}
+
+void
+DesugarTryBlock::go (std::unique_ptr<Expr> &ptr)
+{
+ auto original = static_cast<TryExpr &> (*ptr);
+ auto desugared = DesugarTryBlock ().desugar (original);
+
+ ptr = std::move (desugared);
+}
+
+std::unique_ptr<Expr>
+DesugarTryBlock::desugar (TryExpr &expr)
+{
+ auto builder = Builder (expr.get_locus ());
+ auto &block = expr.get_block_expr ();
+
+ if (block.has_statements ())
+ rust_sorry_at (expr.get_locus (),
+ "cannot desugar try-blocks with statements");
+
+ auto tail_expr = builder.tuple ();
+
+ if (block.has_tail_expr ())
+ tail_expr = block.get_tail_expr ().clone_expr ();
+
+ // Wrap in Try::from_ok call
+ auto from_ok = builder.path_in_expression (LangItem::Kind::TRY_FROM_OK);
+ auto call = builder.call (ptrify (from_ok), std::move (tail_expr));
+
+ return builder.block (std::move (call));
+}
+
+} // namespace AST
+} // namespace Rust
diff --git a/gcc/rust/ast/rust-desugar-try-block.h
b/gcc/rust/ast/rust-desugar-try-block.h
new file mode 100644
index 000000000000..bfd046307af3
--- /dev/null
+++ b/gcc/rust/ast/rust-desugar-try-block.h
@@ -0,0 +1,42 @@
+// Copyright (C) 2025 Free Software Foundation, Inc.
+
+// This file is part of GCC.
+
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#ifndef RUST_DESUGAR_TRY_BLOCK
+#define RUST_DESUGAR_TRY_BLOCK
+
+#include "rust-expr.h"
+
+namespace Rust {
+namespace AST {
+
+// FIXME: Add documentation
+class DesugarTryBlock
+{
+public:
+ static void go (std::unique_ptr<Expr> &ptr);
+
+private:
+ DesugarTryBlock ();
+
+ std::unique_ptr<Expr> desugar (TryExpr &);
+};
+
+} // namespace AST
+} // namespace Rust
+
+#endif // ! RUST_DESUGAR_TRY_BLOCK
diff --git a/gcc/rust/ast/rust-expression-yeast.cc
b/gcc/rust/ast/rust-expression-yeast.cc
index 1089b71034c2..6c0b3d3cced3 100644
--- a/gcc/rust/ast/rust-expression-yeast.cc
+++ b/gcc/rust/ast/rust-expression-yeast.cc
@@ -19,6 +19,7 @@
#include "rust-expression-yeast.h"
#include "rust-ast-visitor.h"
#include "rust-desugar-question-mark.h"
+#include "rust-desugar-try-block.h"
#include "rust-ast-full.h"
namespace Rust {
@@ -39,6 +40,9 @@ ExpressionYeast::dispatch (std::unique_ptr<Expr> &expr)
case Expr::Kind::ErrorPropagation:
DesugarQuestionMark::go (expr);
break;
+ case Expr::Kind::Try:
+ DesugarTryBlock::go (expr);
+ break;
default:
break;
diff --git a/gcc/testsuite/rust/compile/try_block1.rs
b/gcc/testsuite/rust/compile/try_block1.rs
new file mode 100644
index 000000000000..7ae053683e94
--- /dev/null
+++ b/gcc/testsuite/rust/compile/try_block1.rs
@@ -0,0 +1,89 @@
+// { dg-additional-options "-frust-edition=2018" }
+
+#[lang = "sized"]
+trait Sized {}
+
+enum Result<T, E> {
+ Ok(T),
+ Err(E)
+}
+
+pub trait Try {
+ /// The type of this value when viewed as successful.
+ #[unstable(feature = "try_trait", issue = "42327")]
+ type Ok;
+ /// The type of this value when viewed as failed.
+ #[unstable(feature = "try_trait", issue = "42327")]
+ type Error;
+
+ /// Applies the "?" operator. A return of `Ok(t)` means that the
+ /// execution should continue normally, and the result of `?` is the
+ /// value `t`. A return of `Err(e)` means that execution should branch
+ /// to the innermost enclosing `catch`, or return from the function.
+ ///
+ /// If an `Err(e)` result is returned, the value `e` will be "wrapped"
+ /// in the return type of the enclosing scope (which must itself implement
+ /// `Try`). Specifically, the value `X::from_error(From::from(e))`
+ /// is returned, where `X` is the return type of the enclosing function.
+ #[lang = "into_result"]
+ #[unstable(feature = "try_trait", issue = "42327")]
+ fn into_result(self) -> Result<Self::Ok, Self::Error>;
+
+ /// Wrap an error value to construct the composite result. For example,
+ /// `Result::Err(x)` and `Result::from_error(x)` are equivalent.
+ #[lang = "from_error"]
+ #[unstable(feature = "try_trait", issue = "42327")]
+ fn from_error(v: Self::Error) -> Self;
+
+ /// Wrap an OK value to construct the composite result. For example,
+ /// `Result::Ok(x)` and `Result::from_ok(x)` are equivalent.
+ #[lang = "from_ok"]
+ #[unstable(feature = "try_trait", issue = "42327")]
+ fn from_ok(v: Self::Ok) -> Self;
+}
+
+pub struct NoneError;
+
+
+pub enum Option<T> {
+ /// No value
+ None,
+ /// Some value `T`
+ Some(T),
+}
+
+impl<T> Option<T> {
+ pub fn ok_or<E>(self, err: E) -> Result<T, E> {
+ match self {
+ Some(ok) => Result::Ok(ok),
+ None => Result::Err(err)
+ }
+ }
+}
+
+use Option::*;
+
+#[unstable(feature = "try_trait", issue = "42327")]
+impl<T> Try for Option<T> {
+ type Ok = T;
+ type Error = NoneError;
+
+ #[inline]
+ fn into_result(self) -> Result<T, NoneError> {
+ self.ok_or(NoneError)
+ }
+
+ #[inline]
+ fn from_ok(v: T) -> Self {
+ Some(v)
+ }
+
+ #[inline]
+ fn from_error(_: NoneError) -> Self {
+ None
+ }
+}
+
+fn main() {
+ let _: Option<i32> = try { 15i32 };
+}
