Merge #953

953: Refactor lang item mappings r=philberty a=philberty

This refactors how we find our lang items so that during HIR lowering
we have a generic outer attributes handler on Items. The old code only
done lang item mappings during the type check pass and assumed all
lang items are Traits which is not the case. To implement slices range
syntax actually map to structs within libcore/ops/range.rs which have
lang items on structs. This means we can have lang items on any Item.

Co-authored-by: Philip Herron <philip.herron@embecosm.com>

1 files changed, 334 insertions, 0 deletions

diff --git a/gcc/rust/util/rust-lang-item.h b/gcc/rust/util/rust-lang-item.h
new file mode 100644
index 0000000..da200e7
--- /dev/null
+++ b/gcc/rust/util/rust-lang-item.h
@@ -0,0 +1,334 @@
+// Copyright (C) 2020-2022 Free Software Foundation, Inc.
+
+// This file is part of GCC.
+
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+// for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include "rust-system.h"
+#include "operator.h"
+
+namespace Rust {
+namespace Analysis {
+
+// https://github.com/rust-lang/rust/blob/master/library/core/src/ops/arith.rs
+class RustLangItem
+{
+public:
+  enum ItemType
+  {
+    ADD,
+    SUBTRACT,
+    MULTIPLY,
+    DIVIDE,
+    REMAINDER,
+    BITAND,
+    BITOR,
+    BITXOR,
+    SHL,
+    SHR,
+
+    NEGATION,
+    NOT,
+
+    ADD_ASSIGN,
+    SUB_ASSIGN,
+    MUL_ASSIGN,
+    DIV_ASSIGN,
+    REM_ASSIGN,
+    BITAND_ASSIGN,
+    BITOR_ASSIGN,
+    BITXOR_ASSIGN,
+    SHL_ASSIGN,
+    SHR_ASSIGN,
+
+    DEREF,
+    DEREF_MUT,
+
+    // https://github.com/rust-lang/rust/blob/master/library/core/src/ops/range.rs
+    RANGE_FULL,
+    RANGE,
+    RANGE_FROM,
+    RANGE_TO,
+    RANGE_INCLUSIVE,
+    RANGE_TO_INCLUSIVE,
+
+    UNKNOWN,
+  };
+
+  static ItemType Parse (const std::string &item)
+  {
+    if (item.compare ("add") == 0)
+      {
+	return ItemType::ADD;
+      }
+    else if (item.compare ("sub") == 0)
+      {
+	return ItemType::SUBTRACT;
+      }
+    else if (item.compare ("mul") == 0)
+      {
+	return ItemType::MULTIPLY;
+      }
+    else if (item.compare ("div") == 0)
+      {
+	return ItemType::DIVIDE;
+      }
+    else if (item.compare ("rem") == 0)
+      {
+	return ItemType::REMAINDER;
+      }
+    else if (item.compare ("bitand") == 0)
+      {
+	return ItemType::BITAND;
+      }
+    else if (item.compare ("bitor") == 0)
+      {
+	return ItemType::BITOR;
+      }
+    else if (item.compare ("bitxor") == 0)
+      {
+	return ItemType::BITXOR;
+      }
+    else if (item.compare ("shl") == 0)
+      {
+	return ItemType::SHL;
+      }
+    else if (item.compare ("shr") == 0)
+      {
+	return ItemType::SHR;
+      }
+    else if (item.compare ("neg") == 0)
+      {
+	return ItemType::NEGATION;
+      }
+    else if (item.compare ("not") == 0)
+      {
+	return ItemType::NOT;
+      }
+    else if (item.compare ("add_assign") == 0)
+      {
+	return ItemType::ADD_ASSIGN;
+      }
+    else if (item.compare ("sub_assign") == 0)
+      {
+	return ItemType::SUB_ASSIGN;
+      }
+    else if (item.compare ("mul_assign") == 0)
+      {
+	return ItemType::MUL_ASSIGN;
+      }
+    else if (item.compare ("div_assign") == 0)
+      {
+	return ItemType::DIV_ASSIGN;
+      }
+    else if (item.compare ("rem_assign") == 0)
+      {
+	return ItemType::REM_ASSIGN;
+      }
+    else if (item.compare ("bitand_assign") == 0)
+      {
+	return ItemType::BITAND_ASSIGN;
+      }
+    else if (item.compare ("bitor_assign") == 0)
+      {
+	return ItemType::BITOR_ASSIGN;
+      }
+    else if (item.compare ("bitxor_assign") == 0)
+      {
+	return ItemType::BITXOR_ASSIGN;
+      }
+    else if (item.compare ("shl_assign") == 0)
+      {
+	return ItemType::SHL_ASSIGN;
+      }
+    else if (item.compare ("shr_assign") == 0)
+      {
+	return ItemType::SHR_ASSIGN;
+      }
+    else if (item.compare ("deref") == 0)
+      {
+	return ItemType::DEREF;
+      }
+    else if (item.compare ("deref_mut") == 0)
+      {
+	return ItemType::DEREF_MUT;
+      }
+    else if (item.compare ("Range") == 0)
+      {
+	return ItemType::RANGE;
+      }
+    else if (item.compare ("RangeFrom") == 0)
+      {
+	return ItemType::RANGE_FROM;
+      }
+    else if (item.compare ("RangeTo") == 0)
+      {
+	return ItemType::RANGE_TO;
+      }
+    else if (item.compare ("RangeInclusive") == 0)
+      {
+	return ItemType::RANGE_INCLUSIVE;
+      }
+    else if (item.compare ("RangeToInclusive") == 0)
+      {
+	return ItemType::RANGE_TO_INCLUSIVE;
+      }
+
+    return ItemType::UNKNOWN;
+  }
+
+  static std::string ToString (ItemType type)
+  {
+    switch (type)
+      {
+      case ADD:
+	return "add";
+      case SUBTRACT:
+	return "sub";
+      case MULTIPLY:
+	return "mul";
+      case DIVIDE:
+	return "div";
+      case REMAINDER:
+	return "rem";
+      case BITAND:
+	return "bitand";
+      case BITOR:
+	return "bitor";
+      case BITXOR:
+	return "bitxor";
+      case SHL:
+	return "shl";
+      case SHR:
+	return "shr";
+      case NEGATION:
+	return "neg";
+      case NOT:
+	return "not";
+      case ADD_ASSIGN:
+	return "add_assign";
+      case SUB_ASSIGN:
+	return "sub_assign";
+      case MUL_ASSIGN:
+	return "mul_assign";
+      case DIV_ASSIGN:
+	return "div_assign";
+      case REM_ASSIGN:
+	return "rem_assign";
+      case BITAND_ASSIGN:
+	return "bitand_assign";
+      case BITOR_ASSIGN:
+	return "bitor_assign";
+      case BITXOR_ASSIGN:
+	return "bitxor_assign";
+      case SHL_ASSIGN:
+	return "shl_assign";
+      case SHR_ASSIGN:
+	return "shr_assign";
+      case DEREF:
+	return "deref";
+      case DEREF_MUT:
+	return "deref_mut";
+      case RANGE_FULL:
+	return "RangeFull";
+      case RANGE:
+	return "Range";
+      case RANGE_FROM:
+	return "RangeFrom";
+      case RANGE_TO:
+	return "RangeTo";
+      case RANGE_INCLUSIVE:
+	return "RangeInclusive";
+      case RANGE_TO_INCLUSIVE:
+	return "RangeToInclusive";
+
+      case UNKNOWN:
+	return "<UNKNOWN>";
+      }
+    return "<UNKNOWN>";
+  }
+
+  static ItemType OperatorToLangItem (ArithmeticOrLogicalOperator op)
+  {
+    switch (op)
+      {
+      case ArithmeticOrLogicalOperator::ADD:
+	return ItemType::ADD;
+      case ArithmeticOrLogicalOperator::SUBTRACT:
+	return ItemType::SUBTRACT;
+      case ArithmeticOrLogicalOperator::MULTIPLY:
+	return ItemType::MULTIPLY;
+      case ArithmeticOrLogicalOperator::DIVIDE:
+	return ItemType::DIVIDE;
+      case ArithmeticOrLogicalOperator::MODULUS:
+	return ItemType::REMAINDER;
+      case ArithmeticOrLogicalOperator::BITWISE_AND:
+	return ItemType::BITAND;
+      case ArithmeticOrLogicalOperator::BITWISE_OR:
+	return ItemType::BITOR;
+      case ArithmeticOrLogicalOperator::BITWISE_XOR:
+	return ItemType::BITXOR;
+      case ArithmeticOrLogicalOperator::LEFT_SHIFT:
+	return ItemType::SHL;
+      case ArithmeticOrLogicalOperator::RIGHT_SHIFT:
+	return ItemType::SHR;
+      }
+    return ItemType::UNKNOWN;
+  }
+
+  static ItemType
+  CompoundAssignmentOperatorToLangItem (ArithmeticOrLogicalOperator op)
+  {
+    switch (op)
+      {
+      case ArithmeticOrLogicalOperator::ADD:
+	return ItemType::ADD_ASSIGN;
+      case ArithmeticOrLogicalOperator::SUBTRACT:
+	return ItemType::SUB_ASSIGN;
+      case ArithmeticOrLogicalOperator::MULTIPLY:
+	return ItemType::MUL_ASSIGN;
+      case ArithmeticOrLogicalOperator::DIVIDE:
+	return ItemType::DIV_ASSIGN;
+      case ArithmeticOrLogicalOperator::MODULUS:
+	return ItemType::REM_ASSIGN;
+      case ArithmeticOrLogicalOperator::BITWISE_AND:
+	return ItemType::BITAND_ASSIGN;
+      case ArithmeticOrLogicalOperator::BITWISE_OR:
+	return ItemType::BITOR_ASSIGN;
+      case ArithmeticOrLogicalOperator::BITWISE_XOR:
+	return ItemType::BITXOR_ASSIGN;
+      case ArithmeticOrLogicalOperator::LEFT_SHIFT:
+	return ItemType::SHL_ASSIGN;
+      case ArithmeticOrLogicalOperator::RIGHT_SHIFT:
+	return ItemType::SHR_ASSIGN;
+      }
+    return ItemType::UNKNOWN;
+  }
+
+  static ItemType NegationOperatorToLangItem (NegationOperator op)
+  {
+    switch (op)
+      {
+      case NegationOperator::NEGATE:
+	return ItemType::NEGATION;
+      case NegationOperator::NOT:
+	return ItemType::NOT;
+      }
+    return ItemType::UNKNOWN;
+  }
+};
+
+} // namespace Analysis
+} // namespace Rust