From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-x42e.google.com (mail-wr1-x42e.google.com [IPv6:2a00:1450:4864:20::42e]) by sourceware.org (Postfix) with ESMTPS id 9E0B63839DFE for ; Tue, 21 Feb 2023 12:04:04 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 9E0B63839DFE Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=embecosm.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=embecosm.com Received: by mail-wr1-x42e.google.com with SMTP id j2so3982937wrh.9 for ; Tue, 21 Feb 2023 04:04:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=embecosm.com; s=google; h=content-transfer-encoding:mime-version:reply-to:references :in-reply-to:message-id:date:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to; bh=NpuVtdTrDL1+3kjR3aAHmX1YO5DQorK9CoTm1hn8Wxc=; b=d2s6Yzaahm5RSJsj1ClJhUg26GOMu0pK6EcHq6tyGmftfBQC/Dn+NrBoJ5rDFhbr53 rkqqjc+WJWn24LDlxEInqSeJaVOy/9gGvYCln4J/J0k2R6rJ0qvlxeAYkVywF8TLsFHm LoCXcEmfOb2hh73q1N8biqXTHaNy1rP4t9rDs6K2CsarzgU/gqnDgw0H+9SLGffHmzEn foDhaW4hdgf0nBoRG58v6vR1PPMvw7A0tzH+nGpRvPD25VCa/3zfUOqGcJF58UohN4G7 GUZiJJEh98HC/dDAF/uQVry1M6yaj8cByGyaOOr/h+k+4h7Si6PZJevwIQSAh6sCgNkP 45ng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:reply-to:references :in-reply-to:message-id:date:subject:cc:to:from:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=NpuVtdTrDL1+3kjR3aAHmX1YO5DQorK9CoTm1hn8Wxc=; b=IDN12TGyckgmNjXSEZ8WIICwoPCSuxTNBSFSpAqsVVyHtHUK4Y15jzR3JvNk8pwbPn HQJlMCpnOV9179DDTBsTU8+OVtvyTmlQ0gwI4RoKsh3TQpv/d1P8saEqCVwYlR0Z4F/r 8X+Iu5NxMtrYPCVXf/nIxNepazEWb0w0Om0/30OLoDDjLoSRNZ7wbFtXTn5Zi5p+hl/9 YQvdx1fXJ9qm0ZMJpgHn0M3lytlleMb/yHwn2+StTzoAMBR4kEbqjfsv3WCL08wjZYWk mQapVbzbph/u1c0Fk4kOzfu37ZEEBkBZvkvnZFk/qFo03mOnAztAJQ2AT49kAFoZjsuF LAcA== X-Gm-Message-State: AO0yUKXkXYL+CVMnYm4cEB3ReL6jSC+z4EiYz8BXBLoDPd9cA6VDPR0o pkgk/IwRl+cj64CVCCJyACnT X-Google-Smtp-Source: AK7set/65fhGXSCUXTP5rPzdZ/KhN8noTZRsbR/440ea/kkvgodnb+joox8XcAnJCeqAjdyxvgAMNA== X-Received: by 2002:adf:ef0c:0:b0:2c3:f6ff:292c with SMTP id e12-20020adfef0c000000b002c3f6ff292cmr3743056wro.55.1676981044052; Tue, 21 Feb 2023 04:04:04 -0800 (PST) Received: from platypus.localdomain ([62.23.166.218]) by smtp.gmail.com with ESMTPSA id c15-20020adffb4f000000b002c55b0e6ef1sm5013811wrs.4.2023.02.21.04.04.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Feb 2023 04:04:03 -0800 (PST) From: arthur.cohen@embecosm.com To: gcc-patches@gcc.gnu.org Cc: gcc-rust@gcc.gnu.org, Philip Herron Subject: [committed 050/103] gccrs: Closure support at CallExpr Date: Tue, 21 Feb 2023 13:01:40 +0100 Message-Id: <20230221120230.596966-51-arthur.cohen@embecosm.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230221120230.596966-1-arthur.cohen@embecosm.com> References: <20230221120230.596966-1-arthur.cohen@embecosm.com> Reply-To: arthur.cohen@embecosm.com MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-14.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: From: Philip Herron gcc/rust/ChangeLog: * backend/rust-compile-context.h: Add new functions: `insert_closure_decl` and `lookup_closure_decl`. * backend/rust-compile-expr.cc (CompileExpr::visit): Start compiling Closures properly. (CompileExpr::generate_closure_function): New function. (CompileExpr::generate_closure_fntype): Likewise. * backend/rust-compile-expr.h: Declare `generate_closure_function` and `generate_closure_fntype`. * backend/rust-compile-type.cc (TyTyResolveCompile::visit): Visit closure types properly. * backend/rust-mangle.cc (legacy_mangle_name): Add support for closures. * backend/rust-tree.h (RS_CLOSURE_FLAG): Add new tree macro. (RS_CLOSURE_TYPE_P): And checking for it on tree nodes. * typecheck/rust-tyty.cc (ClosureType::is_equal): Add implementation. gcc/testsuite/ChangeLog: * rust/execute/torture/closure1.rs: New test. --- gcc/rust/backend/rust-compile-context.h | 31 ++ gcc/rust/backend/rust-compile-expr.cc | 280 +++++++++++++++++- gcc/rust/backend/rust-compile-expr.h | 10 + gcc/rust/backend/rust-compile-type.cc | 10 +- gcc/rust/backend/rust-mangle.cc | 6 + gcc/rust/backend/rust-tree.h | 5 + gcc/rust/typecheck/rust-tyty.cc | 13 +- .../rust/execute/torture/closure1.rs | 18 ++ 8 files changed, 361 insertions(+), 12 deletions(-) create mode 100644 gcc/testsuite/rust/execute/torture/closure1.rs diff --git a/gcc/rust/backend/rust-compile-context.h b/gcc/rust/backend/rust-compile-context.h index 49f78e19b20..d2d3a53f182 100644 --- a/gcc/rust/backend/rust-compile-context.h +++ b/gcc/rust/backend/rust-compile-context.h @@ -147,6 +147,35 @@ public: mono_fns[dId].push_back ({ref, fn}); } + void insert_closure_decl (const TyTy::ClosureType *ref, tree fn) + { + auto dId = ref->get_def_id (); + auto it = mono_closure_fns.find (dId); + if (it == mono_closure_fns.end ()) + mono_closure_fns[dId] = {}; + + mono_closure_fns[dId].push_back ({ref, fn}); + } + + tree lookup_closure_decl (const TyTy::ClosureType *ref) + { + auto dId = ref->get_def_id (); + auto it = mono_closure_fns.find (dId); + if (it == mono_closure_fns.end ()) + return error_mark_node; + + for (auto &i : it->second) + { + const TyTy::ClosureType *t = i.first; + tree fn = i.second; + + if (ref->is_equal (*t)) + return fn; + } + + return error_mark_node; + } + bool lookup_function_decl (HirId id, tree *fn, DefId dId = UNKNOWN_DEFID, const TyTy::BaseType *ref = nullptr, const std::string &asm_name = std::string ()) @@ -343,6 +372,8 @@ private: std::vector loop_begin_labels; std::map>> mono_fns; + std::map>> + mono_closure_fns; std::map implicit_pattern_bindings; std::map main_variants; diff --git a/gcc/rust/backend/rust-compile-expr.cc b/gcc/rust/backend/rust-compile-expr.cc index 724a93a68bd..d2d9ae0a233 100644 --- a/gcc/rust/backend/rust-compile-expr.cc +++ b/gcc/rust/backend/rust-compile-expr.cc @@ -1589,9 +1589,7 @@ CompileExpr::visit (HIR::CallExpr &expr) } // must be a tuple constructor - bool is_fn = tyty->get_kind () == TyTy::TypeKind::FNDEF - || tyty->get_kind () == TyTy::TypeKind::FNPTR; - bool is_adt_ctor = !is_fn; + bool is_adt_ctor = tyty->get_kind () == TyTy::TypeKind::ADT; if (is_adt_ctor) { rust_assert (tyty->get_kind () == TyTy::TypeKind::ADT); @@ -1692,6 +1690,57 @@ CompileExpr::visit (HIR::CallExpr &expr) return true; }; + auto fn_address = CompileExpr::Compile (expr.get_fnexpr (), ctx); + + // is this a closure call? + if (RS_CLOSURE_TYPE_P (TREE_TYPE (fn_address))) + { + rust_assert (tyty->get_kind () == TyTy::TypeKind::CLOSURE); + TyTy::ClosureType *closure = static_cast (tyty); + + std::vector tuple_arg_vals; + for (auto &argument : expr.get_arguments ()) + { + auto rvalue = CompileExpr::Compile (argument.get (), ctx); + tuple_arg_vals.push_back (rvalue); + } + + tree tuple_args_tyty + = TyTyResolveCompile::compile (ctx, &closure->get_parameters ()); + tree tuple_args + = ctx->get_backend ()->constructor_expression (tuple_args_tyty, false, + tuple_arg_vals, -1, + expr.get_locus ()); + + // need to apply any autoderef's to the self argument + HirId autoderef_mappings_id = expr.get_mappings ().get_hirid (); + std::vector *adjustments = nullptr; + bool ok + = ctx->get_tyctx ()->lookup_autoderef_mappings (autoderef_mappings_id, + &adjustments); + rust_assert (ok); + + // apply adjustments for the fn call + tree self + = resolve_adjustements (*adjustments, fn_address, expr.get_locus ()); + + // args are always self, and the tuple of the args we are passing where + // self is the path of the call-expr in this case the fn_address + std::vector args; + args.push_back (self); + args.push_back (tuple_args); + + // get the fn call address + tree closure_call_site = ctx->lookup_closure_decl (closure); + tree closure_call_address + = address_expression (closure_call_site, expr.get_locus ()); + translated + = ctx->get_backend ()->call_expression (closure_call_address, args, + nullptr /* static chain ?*/, + expr.get_locus ()); + return; + } + bool is_varadic = false; if (tyty->get_kind () == TyTy::TypeKind::FNDEF) { @@ -1699,13 +1748,13 @@ CompileExpr::visit (HIR::CallExpr &expr) is_varadic = fn->is_varadic (); } - size_t required_num_args; + size_t required_num_args = expr.get_arguments ().size (); if (tyty->get_kind () == TyTy::TypeKind::FNDEF) { const TyTy::FnType *fn = static_cast (tyty); required_num_args = fn->num_params (); } - else + else if (tyty->get_kind () == TyTy::TypeKind::FNPTR) { const TyTy::FnPtr *fn = static_cast (tyty); required_num_args = fn->num_params (); @@ -1746,8 +1795,7 @@ CompileExpr::visit (HIR::CallExpr &expr) args.push_back (rvalue); } - // must be a call to a function - auto fn_address = CompileExpr::Compile (expr.get_fnexpr (), ctx); + // must be a regular call to a function translated = ctx->get_backend ()->call_expression (fn_address, args, nullptr, expr.get_locus ()); } @@ -2806,7 +2854,223 @@ CompileExpr::visit (HIR::ArrayIndexExpr &expr) void CompileExpr::visit (HIR::ClosureExpr &expr) { - gcc_unreachable (); + TyTy::BaseType *closure_expr_ty = nullptr; + if (!ctx->get_tyctx ()->lookup_type (expr.get_mappings ().get_hirid (), + &closure_expr_ty)) + { + rust_fatal_error (expr.get_locus (), + "did not resolve type for this ClosureExpr"); + return; + } + rust_assert (closure_expr_ty->get_kind () == TyTy::TypeKind::CLOSURE); + TyTy::ClosureType *closure_tyty + = static_cast (closure_expr_ty); + tree compiled_closure_tyty = TyTyResolveCompile::compile (ctx, closure_tyty); + + // generate closure function + generate_closure_function (expr, *closure_tyty, compiled_closure_tyty); + + // lets ignore state capture for now we need to instantiate the struct anyway + // then generate the function + + std::vector vals; + // TODO + // setup argument captures based on the mode? + + translated + = ctx->get_backend ()->constructor_expression (compiled_closure_tyty, false, + vals, -1, expr.get_locus ()); +} + +tree +CompileExpr::generate_closure_function (HIR::ClosureExpr &expr, + TyTy::ClosureType &closure_tyty, + tree compiled_closure_tyty) +{ + TyTy::FnType *fn_tyty = nullptr; + tree compiled_fn_type + = generate_closure_fntype (expr, closure_tyty, compiled_closure_tyty, + &fn_tyty); + if (compiled_fn_type == error_mark_node) + return error_mark_node; + + const Resolver::CanonicalPath &parent_canonical_path + = closure_tyty.get_ident ().path; + Resolver::CanonicalPath path = parent_canonical_path.append ( + Resolver::CanonicalPath::new_seg (UNKNOWN_NODEID, "{{closure}}")); + + std::string ir_symbol_name = path.get (); + std::string asm_name = ctx->mangle_item (&closure_tyty, path); + + unsigned int flags = 0; + tree fndecl + = ctx->get_backend ()->function (compiled_fn_type, ir_symbol_name, asm_name, + flags, expr.get_locus ()); + + // insert into the context + ctx->insert_function_decl (fn_tyty, fndecl); + ctx->insert_closure_decl (&closure_tyty, fndecl); + + // setup the parameters + std::vector param_vars; + + // closure self + Bvariable *self_param + = ctx->get_backend ()->parameter_variable (fndecl, "$closure", + compiled_closure_tyty, + expr.get_locus ()); + DECL_ARTIFICIAL (self_param->get_decl ()) = 1; + param_vars.push_back (self_param); + + // setup the implicit argument captures + // TODO + + // args tuple + tree args_type + = TyTyResolveCompile::compile (ctx, &closure_tyty.get_parameters ()); + Bvariable *args_param + = ctx->get_backend ()->parameter_variable (fndecl, "args", args_type, + expr.get_locus ()); + param_vars.push_back (args_param); + + // setup the implicit mappings for the arguments. Since argument passing to + // closure functions is done via passing a tuple but the closure body expects + // just normal arguments this means we need to destructure them similar to + // what we do in MatchExpr's. This means when we have a closure-param of a we + // actually setup the destructure to take from the args tuple + + tree args_param_expr = args_param->get_tree (expr.get_locus ()); + size_t i = 0; + for (auto &closure_param : expr.get_params ()) + { + tree compiled_param_var = ctx->get_backend ()->struct_field_expression ( + args_param_expr, i, closure_param.get_locus ()); + + const HIR::Pattern ¶m_pattern = *closure_param.get_pattern (); + ctx->insert_pattern_binding ( + param_pattern.get_pattern_mappings ().get_hirid (), compiled_param_var); + i++; + } + + if (!ctx->get_backend ()->function_set_parameters (fndecl, param_vars)) + return error_mark_node; + + // lookup locals + HIR::Expr *function_body = expr.get_expr ().get (); + auto body_mappings = function_body->get_mappings (); + Resolver::Rib *rib = nullptr; + bool ok + = ctx->get_resolver ()->find_name_rib (body_mappings.get_nodeid (), &rib); + rust_assert (ok); + + std::vector locals + = compile_locals_for_block (ctx, *rib, fndecl); + + tree enclosing_scope = NULL_TREE; + Location start_location = function_body->get_locus (); + Location end_location = function_body->get_locus (); + bool is_block_expr + = function_body->get_expression_type () == HIR::Expr::ExprType::Block; + if (is_block_expr) + { + HIR::BlockExpr *body = static_cast (function_body); + start_location = body->get_locus (); + end_location = body->get_end_locus (); + } + + tree code_block = ctx->get_backend ()->block (fndecl, enclosing_scope, locals, + start_location, end_location); + ctx->push_block (code_block); + + TyTy::BaseType *tyret = &closure_tyty.get_result_type (); + bool function_has_return = !closure_tyty.get_result_type ().is_unit (); + Bvariable *return_address = nullptr; + if (function_has_return) + { + tree return_type = TyTyResolveCompile::compile (ctx, tyret); + + bool address_is_taken = false; + tree ret_var_stmt = NULL_TREE; + + return_address = ctx->get_backend ()->temporary_variable ( + fndecl, code_block, return_type, NULL, address_is_taken, + expr.get_locus (), &ret_var_stmt); + + ctx->add_statement (ret_var_stmt); + } + + ctx->push_fn (fndecl, return_address); + + if (is_block_expr) + { + HIR::BlockExpr *body = static_cast (function_body); + compile_function_body (ctx, fndecl, *body, true); + } + else + { + tree value = CompileExpr::Compile (function_body, ctx); + tree return_expr + = ctx->get_backend ()->return_statement (fndecl, {value}, + function_body->get_locus ()); + ctx->add_statement (return_expr); + } + + tree bind_tree = ctx->pop_block (); + + gcc_assert (TREE_CODE (bind_tree) == BIND_EXPR); + DECL_SAVED_TREE (fndecl) = bind_tree; + + ctx->pop_fn (); + ctx->push_function (fndecl); + + return fndecl; +} + +tree +CompileExpr::generate_closure_fntype (HIR::ClosureExpr &expr, + const TyTy::ClosureType &closure_tyty, + tree compiled_closure_tyty, + TyTy::FnType **fn_tyty) +{ + // grab the specified_bound + rust_assert (closure_tyty.num_specified_bounds () == 1); + const TyTy::TypeBoundPredicate &predicate + = *closure_tyty.get_specified_bounds ().begin (); + + // ensure the fn_once_output associated type is set + closure_tyty.setup_fn_once_output (); + + // the function signature is based on the trait bound that the closure + // implements which is determined at the type resolution time + // + // https://github.com/rust-lang/rust/blob/7807a694c2f079fd3f395821bcc357eee8650071/library/core/src/ops/function.rs#L54-L71 + + TyTy::TypeBoundPredicateItem item = TyTy::TypeBoundPredicateItem::error (); + if (predicate.get_name ().compare ("FnOnce") == 0) + { + item = predicate.lookup_associated_item ("call_once"); + } + else if (predicate.get_name ().compare ("FnMut") == 0) + { + item = predicate.lookup_associated_item ("call_mut"); + } + else if (predicate.get_name ().compare ("Fn") == 0) + { + item = predicate.lookup_associated_item ("call"); + } + else + { + // FIXME error message? + gcc_unreachable (); + return error_mark_node; + } + + rust_assert (!item.is_error ()); + + TyTy::BaseType *item_tyty = item.get_tyty_for_receiver (&closure_tyty); + rust_assert (item_tyty->get_kind () == TyTy::TypeKind::FNDEF); + *fn_tyty = static_cast (item_tyty); + return TyTyResolveCompile::compile (ctx, item_tyty); } } // namespace Compile diff --git a/gcc/rust/backend/rust-compile-expr.h b/gcc/rust/backend/rust-compile-expr.h index 7fc3f5e7f4d..c734406e0da 100644 --- a/gcc/rust/backend/rust-compile-expr.h +++ b/gcc/rust/backend/rust-compile-expr.h @@ -142,6 +142,16 @@ protected: const TyTy::ArrayType &array_tyty, tree array_type, HIR::ArrayElemsCopied &elems); +protected: + tree generate_closure_function (HIR::ClosureExpr &expr, + TyTy::ClosureType &closure_tyty, + tree compiled_closure_tyty); + + tree generate_closure_fntype (HIR::ClosureExpr &expr, + const TyTy::ClosureType &closure_tyty, + tree compiled_closure_tyty, + TyTy::FnType **fn_tyty); + private: CompileExpr (Context *ctx); diff --git a/gcc/rust/backend/rust-compile-type.cc b/gcc/rust/backend/rust-compile-type.cc index fe1b7ce95e3..824cb3a56ef 100644 --- a/gcc/rust/backend/rust-compile-type.cc +++ b/gcc/rust/backend/rust-compile-type.cc @@ -97,9 +97,15 @@ TyTyResolveCompile::visit (const TyTy::InferType &) } void -TyTyResolveCompile::visit (const TyTy::ClosureType &) +TyTyResolveCompile::visit (const TyTy::ClosureType &type) { - gcc_unreachable (); + std::vector fields; + tree type_record = ctx->get_backend ()->struct_type (fields); + RS_CLOSURE_FLAG (type_record) = 1; + + std::string named_struct_str = type.get_ident ().path.get () + "{{closure}}"; + translated = ctx->get_backend ()->named_type (named_struct_str, type_record, + type.get_ident ().locus); } void diff --git a/gcc/rust/backend/rust-mangle.cc b/gcc/rust/backend/rust-mangle.cc index 4d202078a70..83aefa7997a 100644 --- a/gcc/rust/backend/rust-mangle.cc +++ b/gcc/rust/backend/rust-mangle.cc @@ -13,6 +13,8 @@ static const std::string kMangledRef = "$RF$"; static const std::string kMangledPtr = "$BP$"; static const std::string kMangledLeftSqParen = "$u5b$"; // [ static const std::string kMangledRightSqParen = "$u5d$"; // ] +static const std::string kMangledLeftBrace = "$u7b$"; // { +static const std::string kMangledRightBrace = "$u7d$"; // } static const std::string kQualPathBegin = "_" + kMangledSubstBegin; static const std::string kMangledComma = "$C$"; @@ -66,6 +68,10 @@ legacy_mangle_name (const std::string &name) m = kMangledLeftSqParen; else if (c == ']') m = kMangledRightSqParen; + else if (c == '{') + m = kMangledLeftBrace; + else if (c == '}') + m = kMangledRightBrace; else if (c == ',') m = kMangledComma; else if (c == ':') diff --git a/gcc/rust/backend/rust-tree.h b/gcc/rust/backend/rust-tree.h index 41dd012bd6d..284fd873c1c 100644 --- a/gcc/rust/backend/rust-tree.h +++ b/gcc/rust/backend/rust-tree.h @@ -82,6 +82,11 @@ #define SLICE_TYPE_P(TYPE) \ (TREE_CODE (TYPE) == RECORD_TYPE && TREE_LANG_FLAG_0 (TYPE)) +// lambda? +#define RS_CLOSURE_FLAG TREE_LANG_FLAG_1 +#define RS_CLOSURE_TYPE_P(TYPE) \ + (TREE_CODE (TYPE) == RECORD_TYPE && TREE_LANG_FLAG_1 (TYPE)) + /* Returns true if NODE is a pointer to member function type. */ #define TYPE_PTRMEMFUNC_P(NODE) \ (TREE_CODE (NODE) == RECORD_TYPE && TYPE_PTRMEMFUNC_FLAG (NODE)) diff --git a/gcc/rust/typecheck/rust-tyty.cc b/gcc/rust/typecheck/rust-tyty.cc index 0d96c0f04fd..bdb2d909b86 100644 --- a/gcc/rust/typecheck/rust-tyty.cc +++ b/gcc/rust/typecheck/rust-tyty.cc @@ -1696,8 +1696,17 @@ ClosureType::can_eq (const BaseType *other, bool emit_errors) const bool ClosureType::is_equal (const BaseType &other) const { - gcc_unreachable (); - return false; + if (other.get_kind () != TypeKind::CLOSURE) + return false; + + const ClosureType &other2 = static_cast (other); + if (get_def_id () != other2.get_def_id ()) + return false; + + if (!get_parameters ().is_equal (other2.get_parameters ())) + return false; + + return get_result_type ().is_equal (other2.get_result_type ()); } BaseType * diff --git a/gcc/testsuite/rust/execute/torture/closure1.rs b/gcc/testsuite/rust/execute/torture/closure1.rs new file mode 100644 index 00000000000..62afa78a038 --- /dev/null +++ b/gcc/testsuite/rust/execute/torture/closure1.rs @@ -0,0 +1,18 @@ +extern "C" { + fn printf(s: *const i8, ...); +} + +#[lang = "fn_once"] +pub trait FnOnce { + #[lang = "fn_once_output"] + type Output; + + extern "rust-call" fn call_once(self, args: Args) -> Self::Output; +} + +fn main() -> i32 { + let closure_annotated = |i: i32| -> i32 { i + 1 }; + + let i = 1; + closure_annotated(i) - 2 +} -- 2.39.1