Migrate error state to optionals

gcc/rust/ChangeLog:

	* ast/rust-ast-builder.cc (Builder::self_ref_param): Remove error state
	and use optional.
	* ast/rust-ast-visitor.cc (DefaultASTVisitor::visit): Check label
	before visiting.
	* ast/rust-ast.cc (ContinueExpr::as_string): Retrieve label value.
	(Lifetime::as_string): Retrieve lifetime value.
	(ReferenceType::as_string): Likewise.
	(SelfParam::as_string): Likewise.
	* ast/rust-ast.h: Remove lifetime and LifetimeParam error state.
	* ast/rust-desugar-for-loops.cc (DesugarForLoops::DesugarCtx::make_break_arm):
	Use optional instead of error state.
	* ast/rust-expr.h (class ContinueExpr): Make label optional.
	* ast/rust-item.h (class SelfParam): Make lifetime optional.
	* ast/rust-type.h (class ReferenceType): Likewise.
	* backend/rust-compile-base.cc: Use optional for self param instead
	of error state.
	* backend/rust-compile-base.h: Update function prototype.
	* expand/rust-derive-clone.cc (DeriveClone::clone_fn): Use optional.
	* hir/rust-ast-lower-base.cc (ASTLoweringBase::lower_self): Lower
	lifetime only if it exists.
	* hir/rust-ast-lower-block.h: Lower loop label only if it exists.
	* hir/rust-ast-lower-expr.cc (ASTLoweringExpr::visit): Likewise.
	* hir/rust-ast-lower-implitem.cc (ASTLowerImplItem::visit): Remove
	references to error state.
	(ASTLowerTraitItem::visit): Lower self param only if it exists.
	* hir/rust-ast-lower-item.cc (ASTLoweringItem::visit): Use nullopt
	for default value instead of SelfParam error state.
	* hir/rust-ast-lower.cc (ASTLoweringExprWithBlock::visit): Lower label
	only if it exists.
	* hir/rust-hir-dump.cc (Dump::do_traitfunctiondecl): Print self only if
	it exists.
	(Dump::visit): Liewise.
	* hir/tree/rust-hir-bound.h: Remove error state.
	* hir/tree/rust-hir-expr.cc (ContinueExpr::ContinueExpr): Use optional
	in constructor for loop label.
	(BreakExpr::BreakExpr): Likewise.
	* hir/tree/rust-hir-expr.h (class ContinueExpr): Remove error state
	implementation.
	(class BreakExpr): Likewise.
	* hir/tree/rust-hir-generic-param.h: Likewise.
	* hir/tree/rust-hir-item.cc (SelfParam::SelfParam): Make lifetime
	optional.
	(Function::Function): Make self param optional.
	* hir/tree/rust-hir-item.h (class Function): Likewise.
	* hir/tree/rust-hir-type.cc (ReferenceType::ReferenceType): Make
	lifetime optional.
	* hir/tree/rust-hir-type.h (class ReferenceType): Likewise.
	* hir/tree/rust-hir.cc (ContinueExpr::as_string): Use new getter.
	(BreakExpr::as_string): Likewise.
	(Lifetime::as_string): Likewise.
	(ReferenceType::as_string): Likewise.
	(TraitFunctionDecl::as_string): Likewise.
	(SelfParam::as_string): Remove error state checking.
	* parse/rust-parse-impl.h (Parser::parse_generic_param): Adapt to
	optional.
	(Parser::parse_lifetime_params): Likewise.
	(Parser::parse_lifetime_params_objs): Likewise.
	(Parser::parse_lifetime_param): Likewise.
	(Parser::parse_lifetime_where_clause_item): Likewise.
	(Parser::parse_type_param_bound): Likewise.
	(Parser::parse_lifetime_bounds): Likewise.
	(Parser::parse_path_generic_args): Likewise.
	(Parser::parse_self_param): Likewise.
	(Parser::parse_break_expr): Likewise.
	(Parser::parse_continue_expr): Likewise.
	(Parser::parse_reference_type_inner): Likewise.
	* parse/rust-parse.h (class ParseLifetimeParamError): Add new class for
	lifetime param parsing errors.
	(class ParseLifetimeError): Add new class for lifetime parsing errors.
	(enum ParseSelfError): Add new class for self param parsing errors.
	* typecheck/rust-hir-type-check-implitem.cc (TypeCheckImplItem::visit):
	Use unchecked getter in checked context. And make anonymous region.
	* typecheck/rust-hir-type-check.cc (TraitItemReference::get_type_from_fn):
	Likewise.

Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>

1 files changed, 0 insertions, 17 deletions

diff --git a/gcc/rust/ast/rust-ast.h b/gcc/rust/ast/rust-ast.h
index c74b1c4..53bf1bc 100644
--- a/gcc/rust/ast/rust-ast.h
+++ b/gcc/rust/ast/rust-ast.h
@@ -1587,17 +1587,9 @@ public:
       lifetime_name (std::move (name)), locus (locus)
   {}
 
-  // Creates an "error" lifetime.
-  static Lifetime error () { return Lifetime (NAMED, ""); }
-
   static Lifetime elided () { return Lifetime (WILDCARD, ""); }
 
   // Returns true if the lifetime is in an error state.
-  bool is_error () const
-  {
-    return lifetime_type == NAMED && lifetime_name.empty ();
-  }
-
   std::string as_string () const override;
 
   void accept_vis (ASTVisitor &vis) override;
@@ -1688,15 +1680,6 @@ public:
   // Returns whether the lifetime param has an outer attribute.
   bool has_outer_attribute () const { return !outer_attrs.empty (); }
 
-  // Creates an error state lifetime param.
-  static LifetimeParam create_error ()
-  {
-    return LifetimeParam (Lifetime::error (), {}, {}, UNDEF_LOCATION);
-  }
-
-  // Returns whether the lifetime param is in an error state.
-  bool is_error () const { return lifetime.is_error (); }
-
   // Constructor
   LifetimeParam (Lifetime lifetime, std::vector<Lifetime> lifetime_bounds,
 		 AST::AttrVec outer_attrs, location_t locus)