[COMMITTED] gccrs: Desugar double borrows into two HIR:BorrowExpr's
Commit Message
From: Philip Herron <philip.herron@embecosm.com>
We simply hit a gcc_unreachable() on double borrows but it seems reasonable
to just desugar the AST into a borrow of a borrow to foo. Instead of a
borrow expression with a flag to be respected.
Fixes #1506
gcc/rust/ChangeLog:
* hir/rust-ast-lower-expr.h: Lower double borrow expressions to two
`HIR::BorrowExpr`s.
* hir/tree/rust-hir-expr.h: Remove `is_double_borrow` field from
`HIR::BorrowExpr`.
* typecheck/rust-hir-type-check-expr.cc (TypeCheckExpr::visit): Remove
call to `gcc_unreachable` on double borrow expressions.
gcc/testsuite/ChangeLog:
* rust/compile/torture/issue-1506.rs: New test.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/rust/hir/rust-ast-lower-expr.h | 27 ++++++++++++++++---
gcc/rust/hir/tree/rust-hir-expr.h | 5 ++--
.../typecheck/rust-hir-type-check-expr.cc | 6 -----
.../rust/compile/torture/issue-1506.rs | 3 +++
4 files changed, 28 insertions(+), 13 deletions(-)
create mode 100644 gcc/testsuite/rust/compile/torture/issue-1506.rs
@@ -643,10 +643,29 @@ public:
mappings->get_next_hir_id (crate_num),
UNKNOWN_LOCAL_DEFID);
- translated = new HIR::BorrowExpr (
- mapping, std::unique_ptr<HIR::Expr> (borrow_lvalue),
- expr.get_is_mut () ? Mutability::Mut : Mutability::Imm,
- expr.get_is_double_borrow (), expr.get_outer_attrs (), expr.get_locus ());
+ HIR::BorrowExpr *borrow_expr
+ = new HIR::BorrowExpr (mapping,
+ std::unique_ptr<HIR::Expr> (borrow_lvalue),
+ expr.get_is_mut () ? Mutability::Mut
+ : Mutability::Imm,
+ expr.get_outer_attrs (), expr.get_locus ());
+
+ if (expr.get_is_double_borrow ())
+ {
+ NodeId artifical_bouble_borrow_id = mappings->get_next_node_id ();
+ Analysis::NodeMapping mapping (crate_num, artifical_bouble_borrow_id,
+ mappings->get_next_hir_id (crate_num),
+ UNKNOWN_LOCAL_DEFID);
+
+ borrow_expr
+ = new HIR::BorrowExpr (mapping,
+ std::unique_ptr<HIR::Expr> (borrow_expr),
+ expr.get_is_mut () ? Mutability::Mut
+ : Mutability::Imm,
+ expr.get_outer_attrs (), expr.get_locus ());
+ }
+
+ translated = borrow_expr;
}
void visit (AST::DereferenceExpr &expr) override
@@ -192,10 +192,10 @@ public:
BorrowExpr (Analysis::NodeMapping mappings,
std::unique_ptr<Expr> borrow_lvalue, Mutability mut,
- bool is_double_borrow, AST::AttrVec outer_attribs, Location locus)
+ AST::AttrVec outer_attribs, Location locus)
: OperatorExpr (std::move (mappings), std::move (borrow_lvalue),
std::move (outer_attribs), locus),
- mut (mut), double_borrow (is_double_borrow)
+ mut (mut)
{}
void accept_vis (HIRFullVisitor &vis) override;
@@ -203,7 +203,6 @@ public:
Mutability get_mut () const { return mut; }
bool is_mut () const { return mut == Mutability::Mut; }
- bool get_is_double_borrow () const { return double_borrow; }
protected:
/* Use covariance to implement clone function as returning this object rather
@@ -1209,12 +1209,6 @@ TypeCheckExpr::visit (HIR::BorrowExpr &expr)
}
}
- if (expr.get_is_double_borrow ())
- {
- // FIXME double_reference
- gcc_unreachable ();
- }
-
infered = new TyTy::ReferenceType (expr.get_mappings ().get_hirid (),
TyTy::TyVar (resolved_base->get_ref ()),
expr.get_mut ());
new file mode 100644
@@ -0,0 +1,3 @@
+pub fn main() {
+ let _: &i32 = &&&&1;
+}