gcc/rust/typecheck/rust-coercion.h

   1 // Copyright (C) 2020-2025 Free Software Foundation, Inc.
   2
   3 // This file is part of GCC.
   4
   5 // GCC is free software; you can redistribute it and/or modify it under
   6 // the terms of the GNU General Public License as published by the Free
   7 // Software Foundation; either version 3, or (at your option) any later
   8 // version.
   9
  10 // GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  11 // WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 // FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13 // for more details.
  14
  15 // You should have received a copy of the GNU General Public License
  16 // along with GCC; see the file COPYING3.  If not see
  17 // <http://www.gnu.org/licenses/>.
  18
  19 #ifndef RUST_COERCION
  20 #define RUST_COERCION
  21
  22 #include "rust-autoderef.h"
  23 #include "rust-hir-type-check.h"
  24
  25 namespace Rust {
  26 namespace Resolver {
  27
  28 class TypeCoercionRules : protected AutoderefCycle
  29 {
  30 public:
  31   struct CoercionResult
  32   {
  33     std::vector<Adjustment> adjustments;
  34     TyTy::BaseType *tyty;
  35
  36     bool is_error ()
  37     {
  38       return tyty == nullptr || tyty->get_kind () == TyTy::TypeKind::ERROR;
  39     }
  40
  41     static CoercionResult get_error () { return CoercionResult{{}, nullptr}; }
  42   };
  43
  44   static CoercionResult Coerce (TyTy::BaseType *receiver,
  45                                 TyTy::BaseType *expected, location_t locus,
  46                                 bool allow_autoderef,
  47                                 bool is_cast_site = false);
  48
  49   static CoercionResult TryCoerce (TyTy::BaseType *receiver,
  50                                    TyTy::BaseType *expected, location_t locus,
  51                                    bool allow_autoderef,
  52                                    bool is_cast_site = false);
  53
  54   CoercionResult coerce_unsafe_ptr (TyTy::BaseType *receiver,
  55                                     TyTy::PointerType *expected,
  56                                     Mutability mutability);
  57
  58   CoercionResult coerce_borrowed_pointer (TyTy::BaseType *receiver,
  59                                           TyTy::ReferenceType *expected,
  60                                           Mutability mutability);
  61
  62   CoercionResult coerce_unsized (TyTy::BaseType *receiver,
  63                                  TyTy::BaseType *expected, bool &unsafe_error);
  64
  65   static bool coerceable_mutability (Mutability from_mutbl,
  66                                      Mutability to_mutbl);
  67
  68   void mismatched_mutability_error (location_t expr_locus, location_t lhs,
  69                                     location_t rhs);
  70   void object_unsafe_error (location_t expr_locus, location_t lhs,
  71                             location_t rhs);
  72
  73 protected:
  74   TypeCoercionRules (TyTy::BaseType *expected, location_t locus,
  75                      bool emit_errors, bool allow_autoderef, bool try_flag,
  76                      bool is_cast_site);
  77
  78   bool select (TyTy::BaseType &autoderefed) override;
  79
  80   bool do_coercion (TyTy::BaseType *receiver);
  81
  82 private:
  83   // context info
  84   Analysis::Mappings *mappings;
  85   TypeCheckContext *context;
  86
  87   // search
  88   TyTy::BaseType *expected;
  89   location_t locus;
  90
  91   // mutable fields
  92   CoercionResult try_result;
  93   bool emit_errors;
  94   bool try_flag;
  95   bool is_cast_site;
  96 };
  97
  98 } // namespace Resolver
  99 } // namespace Rust
 100
 101 #endif // RUST_COERCION