From ca514784717ef9c8418968a60ed4641af78c7d7b Mon Sep 17 00:00:00 2001
From: Philip Herron <philip.herron@embecosm.com>
Date: Fri, 12 Feb 2021 14:57:11 +0000
Subject: Add ReferenceType with BorrowExpr and DereferenceExpr

This also adds in the mising InferenceType _ which was mostly implemented
before as part of Data Structures 1.

We create GENERIC REFERENCE_TYPES for these this is the building block
to finish work on mutability rules and pointers.

Fixes: #196
Addresses: #169 #170
---
 gcc/rust/backend/rust-compile-context.h |  7 +++++++
 gcc/rust/backend/rust-compile-expr.h    | 31 +++++++++++++++++++++++++++++++
 gcc/rust/backend/rust-compile-tyty.h    |  2 ++
 3 files changed, 40 insertions(+)

(limited to 'gcc/rust/backend')

diff --git a/gcc/rust/backend/rust-compile-context.h b/gcc/rust/backend/rust-compile-context.h
index 3955a5b..b50e103 100644
--- a/gcc/rust/backend/rust-compile-context.h
+++ b/gcc/rust/backend/rust-compile-context.h
@@ -445,6 +445,13 @@ public:
     translated = compiled_type;
   }
 
+  void visit (TyTy::ReferenceType &type) override
+  {
+    Btype *base_compiled_type
+      = TyTyResolveCompile::compile (ctx, type.get_base ());
+    translated = ctx->get_backend ()->reference_type (base_compiled_type);
+  }
+
 private:
   TyTyResolveCompile (Context *ctx) : ctx (ctx) {}
 
diff --git a/gcc/rust/backend/rust-compile-expr.h b/gcc/rust/backend/rust-compile-expr.h
index c63479c..842804d 100644
--- a/gcc/rust/backend/rust-compile-expr.h
+++ b/gcc/rust/backend/rust-compile-expr.h
@@ -816,6 +816,37 @@ public:
     ctx->add_statement (goto_label);
   }
 
+  void visit (HIR::BorrowExpr &expr)
+  {
+    Bexpression *main_expr
+      = CompileExpr::Compile (expr.get_expr ().get (), ctx);
+
+    translated
+      = ctx->get_backend ()->address_expression (main_expr, expr.get_locus ());
+  }
+
+  void visit (HIR::DereferenceExpr &expr)
+  {
+    Bexpression *main_expr
+      = CompileExpr::Compile (expr.get_expr ().get (), ctx);
+
+    TyTy::TyBase *tyty = nullptr;
+    if (!ctx->get_tyctx ()->lookup_type (expr.get_mappings ().get_hirid (),
+					 &tyty))
+      {
+	rust_fatal_error (expr.get_locus (),
+			  "did not resolve type for this TupleExpr");
+	return;
+      }
+
+    Btype *expected_type = TyTyResolveCompile::compile (ctx, tyty);
+    bool known_valid = true;
+    translated
+      = ctx->get_backend ()->indirect_expression (expected_type, main_expr,
+						  known_valid,
+						  expr.get_locus ());
+  }
+
 private:
   CompileExpr (Context *ctx) : HIRCompileBase (ctx), translated (nullptr) {}
 
diff --git a/gcc/rust/backend/rust-compile-tyty.h b/gcc/rust/backend/rust-compile-tyty.h
index f591696..eb8a961 100644
--- a/gcc/rust/backend/rust-compile-tyty.h
+++ b/gcc/rust/backend/rust-compile-tyty.h
@@ -56,6 +56,8 @@ public:
 
   void visit (TyTy::ArrayType &) override { gcc_unreachable (); }
 
+  void visit (TyTy::ReferenceType &) override { gcc_unreachable (); }
+
   void visit (TyTy::UnitType &) override { translated = backend->void_type (); }
 
   void visit (TyTy::FnType &type) override
-- 
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