gcc/rust/backend/rust-compile-var-decl.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_COMPILE_VAR_DECL
  20 #define RUST_COMPILE_VAR_DECL
  21
  22 #include "rust-compile-base.h"
  23 #include "rust-hir-visitor.h"
  24
  25 namespace Rust {
  26 namespace Compile {
  27
  28 class CompileVarDecl : public HIRCompileBase, public HIR::HIRPatternVisitor
  29 {
  30   using HIR::HIRPatternVisitor::visit;
  31
  32 public:
  33   static std::vector<Bvariable *> compile (tree fndecl, tree translated_type,
  34                                            HIR::Pattern *pattern, Context *ctx)
  35   {
  36     CompileVarDecl compiler (ctx, fndecl, translated_type);
  37     pattern->accept_vis (compiler);
  38     return compiler.vars;
  39   }
  40
  41   void visit (HIR::IdentifierPattern &pattern) override
  42   {
  43     if (!pattern.is_mut ())
  44       translated_type = Backend::immutable_type (translated_type);
  45
  46     tree bind_tree = ctx->peek_enclosing_scope ();
  47     std::string identifier = pattern.get_identifier ().as_string ();
  48     tree decl
  49       = build_decl (pattern.get_locus (), VAR_DECL,
  50                     Backend::get_identifier_node (identifier), translated_type);
  51     DECL_CONTEXT (decl) = fndecl;
  52
  53     gcc_assert (TREE_CODE (bind_tree) == BIND_EXPR);
  54     tree block_tree = BIND_EXPR_BLOCK (bind_tree);
  55     gcc_assert (TREE_CODE (block_tree) == BLOCK);
  56     DECL_CHAIN (decl) = BLOCK_VARS (block_tree);
  57     BLOCK_VARS (block_tree) = decl;
  58     BIND_EXPR_VARS (bind_tree) = BLOCK_VARS (block_tree);
  59
  60     rust_preserve_from_gc (decl);
  61     Bvariable *var = new Bvariable (decl);
  62
  63     HirId stmt_id = pattern.get_mappings ().get_hirid ();
  64     ctx->insert_var_decl (stmt_id, var);
  65
  66     vars.push_back (var);
  67   }
  68
  69   void visit (HIR::TuplePattern &pattern) override
  70   {
  71     switch (pattern.get_items ().get_item_type ())
  72       {
  73         case HIR::TuplePatternItems::ItemType::MULTIPLE: {
  74           rust_assert (TREE_CODE (translated_type) == RECORD_TYPE);
  75           auto &items = static_cast<HIR::TuplePatternItemsMultiple &> (
  76             pattern.get_items ());
  77
  78           size_t offs = 0;
  79           for (auto &sub : items.get_patterns ())
  80             {
  81               tree sub_ty = error_mark_node;
  82               tree field = TYPE_FIELDS (translated_type);
  83               for (size_t i = 0; i < offs; i++)
  84                 {
  85                   field = DECL_CHAIN (field);
  86                   gcc_assert (field != NULL_TREE);
  87                 }
  88               sub_ty = TREE_TYPE (field);
  89               CompileVarDecl::compile (fndecl, sub_ty, sub.get (), ctx);
  90               offs++;
  91             }
  92         }
  93         break;
  94
  95       default:
  96         break;
  97       }
  98   }
  99
 100   // Empty visit for unused Pattern HIR nodes.
 101   void visit (HIR::AltPattern &) override {}
 102   void visit (HIR::LiteralPattern &) override {}
 103   void visit (HIR::PathInExpression &) override {}
 104   void visit (HIR::QualifiedPathInExpression &) override {}
 105   void visit (HIR::RangePattern &) override {}
 106   void visit (HIR::ReferencePattern &) override {}
 107   void visit (HIR::SlicePattern &) override {}
 108   void visit (HIR::StructPattern &) override {}
 109   void visit (HIR::TupleStructPattern &) override {}
 110   void visit (HIR::WildcardPattern &) override {}
 111
 112 private:
 113   CompileVarDecl (Context *ctx, tree fndecl, tree translated_type)
 114     : HIRCompileBase (ctx), fndecl (fndecl), translated_type (translated_type)
 115   {}
 116
 117   tree fndecl;
 118   tree translated_type;
 119
 120   std::vector<Bvariable *> vars;
 121 };
 122
 123 } // namespace Compile
 124 } // namespace Rust
 125
 126 #endif // RUST_COMPILE_VAR_DECL