[PATCH] Support byte and byte string literals

[PATCH] Support byte and byte string literals

[Mark Wielaard]

A byte literal is an u8 created as a ascii char or hex escape
e.g. b'X'.  A byte string literal is a string created from ascii or
hex chars. bytes are represented as u8 and byte strings as str (with
just ascii < 256 chars), but it should really be &'static [u8; n].
---
 gcc/rust/backend/rust-compile-expr.h          |  9 ++++++++-
 gcc/rust/parse/rust-parse-impl.h              |  8 ++++++++
 gcc/rust/rust-backend.h                       |  3 +++
 gcc/rust/rust-gcc.cc                          |  9 +++++++++
 gcc/rust/typecheck/rust-hir-type-check-expr.h | 19 +++++++++++++++++++
 .../rust/compile/torture/byte_char_str.rs     |  8 ++++++++
 6 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/rust/compile/torture/byte_char_str.rs

diff --git a/gcc/rust/backend/rust-compile-expr.h b/gcc/rust/backend/rust-compile-expr.h
index dff4712e18e..fa6a53991ac 100644
--- a/gcc/rust/backend/rust-compile-expr.h
+++ b/gcc/rust/backend/rust-compile-expr.h
@@ -278,7 +278,14 @@ public:
 	}
 	return;
 
-	case HIR::Literal::STRING: {
+	case HIR::Literal::BYTE: {
+	  char c = literal_value->as_string ().c_str ()[0];
+	  translated = ctx->get_backend ()->char_constant_expression (c);
+	}
+	return;
+
+      case HIR::Literal::STRING:
+	case HIR::Literal::BYTE_STRING: {
 	  auto base = ctx->get_backend ()->string_constant_expression (
 	    literal_value->as_string ());
 	  translated
diff --git a/gcc/rust/parse/rust-parse-impl.h b/gcc/rust/parse/rust-parse-impl.h
index be261715c6c..73600d22d60 100644
--- a/gcc/rust/parse/rust-parse-impl.h
+++ b/gcc/rust/parse/rust-parse-impl.h
@@ -12545,10 +12545,18 @@ Parser<ManagedTokenSource>::null_denotation (const_TokenPtr tok,
       return std::unique_ptr<AST::LiteralExpr> (
 	new AST::LiteralExpr (tok->get_str (), AST::Literal::STRING,
 			      tok->get_type_hint (), {}, tok->get_locus ()));
+    case BYTE_STRING_LITERAL:
+      return std::unique_ptr<AST::LiteralExpr> (
+	new AST::LiteralExpr (tok->get_str (), AST::Literal::BYTE_STRING,
+			      tok->get_type_hint (), {}, tok->get_locus ()));
     case CHAR_LITERAL:
       return std::unique_ptr<AST::LiteralExpr> (
 	new AST::LiteralExpr (tok->get_str (), AST::Literal::CHAR,
 			      tok->get_type_hint (), {}, tok->get_locus ()));
+    case BYTE_CHAR_LITERAL:
+      return std::unique_ptr<AST::LiteralExpr> (
+	new AST::LiteralExpr (tok->get_str (), AST::Literal::BYTE,
+			      tok->get_type_hint (), {}, tok->get_locus ()));
     case TRUE_LITERAL:
       return std::unique_ptr<AST::LiteralExpr> (
 	new AST::LiteralExpr ("true", AST::Literal::BOOL, tok->get_type_hint (),
diff --git a/gcc/rust/rust-backend.h b/gcc/rust/rust-backend.h
index 35271b60f43..1dd4aba12ca 100644
--- a/gcc/rust/rust-backend.h
+++ b/gcc/rust/rust-backend.h
@@ -331,6 +331,9 @@ public:
   // Return an expression for the string value VAL.
   virtual Bexpression *string_constant_expression (const std::string &val) = 0;
 
+  // Get a char literal
+  virtual Bexpression *char_constant_expression (char c) = 0;
+
   // Get a char literal
   virtual Bexpression *wchar_constant_expression (wchar_t c) = 0;
 
diff --git a/gcc/rust/rust-gcc.cc b/gcc/rust/rust-gcc.cc
index 74a8b5221f1..23a91ad9bcb 100644
--- a/gcc/rust/rust-gcc.cc
+++ b/gcc/rust/rust-gcc.cc
@@ -333,6 +333,8 @@ public:
 
   Bexpression *wchar_constant_expression (wchar_t c);
 
+  Bexpression *char_constant_expression (char c);
+
   Bexpression *boolean_constant_expression (bool val);
 
   Bexpression *real_part_expression (Bexpression *bcomplex, Location);
@@ -1557,6 +1559,13 @@ Gcc_backend::wchar_constant_expression (wchar_t c)
   return this->make_expression (ret);
 }
 
+Bexpression *
+Gcc_backend::char_constant_expression (char c)
+{
+  tree ret = build_int_cst (this->char_type ()->get_tree (), c);
+  return this->make_expression (ret);
+}
+
 // Make a constant boolean expression.
 
 Bexpression *
diff --git a/gcc/rust/typecheck/rust-hir-type-check-expr.h b/gcc/rust/typecheck/rust-hir-type-check-expr.h
index 166535acba0..6e5b2312f50 100644
--- a/gcc/rust/typecheck/rust-hir-type-check-expr.h
+++ b/gcc/rust/typecheck/rust-hir-type-check-expr.h
@@ -542,6 +542,12 @@ public:
 	}
 	break;
 
+	case HIR::Literal::LitType::BYTE: {
+	  auto ok = context->lookup_builtin ("u8", &infered);
+	  rust_assert (ok);
+	}
+	break;
+
 	case HIR::Literal::LitType::STRING: {
 	  TyTy::BaseType *base = nullptr;
 	  auto ok = context->lookup_builtin ("str", &base);
@@ -553,6 +559,19 @@ public:
 	}
 	break;
 
+	case HIR::Literal::LitType::BYTE_STRING: {
+	  /* We just treat this as a string, but it really is an arraytype of
+	     u8. It isn't in UTF-8, but really just a byte array.  */
+	  TyTy::BaseType *base = nullptr;
+	  auto ok = context->lookup_builtin ("str", &base);
+	  rust_assert (ok);
+
+	  infered
+	    = new TyTy::ReferenceType (expr.get_mappings ().get_hirid (),
+				       TyTy::TyVar (base->get_ref ()), false);
+	}
+	break;
+
       default:
 	gcc_unreachable ();
 	break;
diff --git a/gcc/testsuite/rust/compile/torture/byte_char_str.rs b/gcc/testsuite/rust/compile/torture/byte_char_str.rs
new file mode 100644
index 00000000000..bc3ec5014e8
--- /dev/null
+++ b/gcc/testsuite/rust/compile/torture/byte_char_str.rs
@@ -0,0 +1,8 @@
+pub fn main ()
+{
+  let _c = 'x';
+  let _bc = b'x';
+
+  let _s = "abc";
+  let _bs = b"abc";
+}
-- 
2.32.0