[COMMITTED 60/77] gccrs: lang: Add range_inclusive_new

[arthur.cohen@embecosm.com]

From: Enes Cevik <enes@nsvke.com>

This patch introduces the 'range_inclusive_new' lang item to the compiler.
When the compiler encounters an inclusive range expression, it now
correctly desugars the operation into a function call targeting this
lang item instead of lowering it directly into a static struct.

gcc/rust/ChangeLog:

	* hir/rust-ast-lower-expr.cc (ASTLoweringExpr::visit): Add
	desugaring for range_inclusive_new lang item.
	* util/rust-lang-item.cc (Rust::LangItem::lang_items): Add
	range_inclusive_new to the BiMap.
	* util/rust-lang-item.h (class LangItem): Add RANGE_INCLUSIVE_NEW
	to the Kind enum.

gcc/testsuite/ChangeLog:

	* rust/compile/torture/range-lang-item1.rs: Update test to use
	the new lang item.

Signed-off-by: Enes Cevik <enes@nsvke.com>
---
 gcc/rust/hir/rust-ast-lower-expr.cc           | 26 ++++++++++++++-----
 gcc/rust/util/rust-lang-item.cc               |  1 +
 gcc/rust/util/rust-lang-item.h                |  1 +
 .../rust/compile/torture/range-lang-item1.rs  | 12 +++++++++
 4 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/gcc/rust/hir/rust-ast-lower-expr.cc b/gcc/rust/hir/rust-ast-lower-expr.cc
index f41ba8bcf8c..0e934307755 100644
--- a/gcc/rust/hir/rust-ast-lower-expr.cc
+++ b/gcc/rust/hir/rust-ast-lower-expr.cc
@@ -796,18 +796,30 @@ void
 ASTLoweringExpr::visit (AST::RangeFromToInclExpr &expr)
 {
   auto crate_num = mappings.get_current_crate ();
-  Analysis::NodeMapping mapping (crate_num, expr.get_node_id (),
-				 mappings.get_next_hir_id (crate_num),
-				 UNKNOWN_LOCAL_DEFID);
+  Analysis::NodeMapping path_mapping (crate_num, mappings.get_next_node_id (),
+				      mappings.get_next_hir_id (crate_num),
+				      UNKNOWN_LOCAL_DEFID);
+  Analysis::NodeMapping call_mapping (crate_num, expr.get_node_id (),
+				      mappings.get_next_hir_id (crate_num),
+				      UNKNOWN_LOCAL_DEFID);
+
+  HIR::Expr *func
+    = new HIR::PathInExpression (path_mapping,
+				 LangItem::Kind::RANGE_INCLUSIVE_NEW,
+				 expr.get_locus (), false);
 
   HIR::Expr *range_from = ASTLoweringExpr::translate (expr.get_from_expr ());
   HIR::Expr *range_to = ASTLoweringExpr::translate (expr.get_to_expr ());
 
+  std::vector<std::unique_ptr<HIR::Expr>> params;
+  params.reserve (2);
+  params.emplace_back (std::unique_ptr<HIR::Expr> (range_from));
+  params.emplace_back (std::unique_ptr<HIR::Expr> (range_to));
+
   translated
-    = new HIR::RangeFromToInclExpr (mapping,
-				    std::unique_ptr<HIR::Expr> (range_from),
-				    std::unique_ptr<HIR::Expr> (range_to),
-				    expr.get_locus ());
+    = new HIR::CallExpr (call_mapping, std::unique_ptr<HIR::Expr> (func),
+			 std::move (params), expr.get_outer_attrs (),
+			 expr.get_locus ());
 }
 
 void
diff --git a/gcc/rust/util/rust-lang-item.cc b/gcc/rust/util/rust-lang-item.cc
index 91284e27b08..731fd23f314 100644
--- a/gcc/rust/util/rust-lang-item.cc
+++ b/gcc/rust/util/rust-lang-item.cc
@@ -55,6 +55,7 @@ const BiMap<std::string, LangItem::Kind> Rust::LangItem::lang_items = {{
   {"RangeTo", Kind::RANGE_TO},
   {"RangeInclusive", Kind::RANGE_INCLUSIVE},
   {"RangeToInclusive", Kind::RANGE_TO_INCLUSIVE},
+  {"range_inclusive_new", Kind::RANGE_INCLUSIVE_NEW},
   {"phantom_data", Kind::PHANTOM_DATA},
   {"fn", Kind::FN},
   {"fn_mut", Kind::FN_MUT},
diff --git a/gcc/rust/util/rust-lang-item.h b/gcc/rust/util/rust-lang-item.h
index d96fa9e6a78..9684148f755 100644
--- a/gcc/rust/util/rust-lang-item.h
+++ b/gcc/rust/util/rust-lang-item.h
@@ -77,6 +77,7 @@ public:
     RANGE_TO,
     RANGE_INCLUSIVE,
     RANGE_TO_INCLUSIVE,
+    RANGE_INCLUSIVE_NEW,
 
     // https://github.com/rust-lang/rust/blob/master/library/core/src/marker.rs
     PHANTOM_DATA,
diff --git a/gcc/testsuite/rust/compile/torture/range-lang-item1.rs b/gcc/testsuite/rust/compile/torture/range-lang-item1.rs
index 8682e5a55ae..328f0cfa72e 100644
--- a/gcc/testsuite/rust/compile/torture/range-lang-item1.rs
+++ b/gcc/testsuite/rust/compile/torture/range-lang-item1.rs
@@ -29,6 +29,18 @@ pub struct RangeTo<Idx> {
 pub struct RangeInclusive<Idx> {
     pub start: Idx,
     pub end: Idx,
+    pub exhausted: bool,
+}
+
+impl<Idx> RangeInclusive<Idx> {
+    #[lang = "range_inclusive_new"]
+    pub const fn new(start: Idx, end: Idx) -> Self {
+        Self {
+            start,
+            end,
+            exhausted: false,
+        }
+    }
 }
 
 fn test() {
-- 
2.50.1