source/assembly_grammar.cpp

// Copyright (c) 2015 The Khronos Group Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and/or associated documentation files (the
// "Materials"), to deal in the Materials without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Materials, and to
// permit persons to whom the Materials are furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Materials.
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// MODIFICATIONS TO THIS FILE MAY MEAN IT NO LONGER ACCURATELY REFLECTS
// KHRONOS STANDARDS. THE UNMODIFIED, NORMATIVE VERSIONS OF KHRONOS
// SPECIFICATIONS AND HEADER INFORMATION ARE LOCATED AT
//    https://www.khronos.org/registry/
//
// THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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#include "assembly_grammar.h"

#include <algorithm>
#include <cassert>
#include <cstring>

#include "ext_inst.h"
#include "opcode.h"
#include "operand.h"

namespace {

/// @brief Parses a mask expression string for the given operand type.
///
/// A mask expression is a sequence of one or more terms separated by '|',
/// where each term a named enum value for the given type.  No whitespace
/// is permitted.
///
/// On success, the value is written to pValue.
///
/// @param[in] operandTable operand lookup table
/// @param[in] type of the operand
/// @param[in] textValue word of text to be parsed
/// @param[out] pValue where the resulting value is written
///
/// @return result code
spv_result_t spvTextParseMaskOperand(const spv_operand_table operandTable,
                                     const spv_operand_type_t type,
                                     const char* textValue, uint32_t* pValue) {
  if (textValue == nullptr) return SPV_ERROR_INVALID_TEXT;
  size_t text_length = strlen(textValue);
  if (text_length == 0) return SPV_ERROR_INVALID_TEXT;
  const char* text_end = textValue + text_length;

  // We only support mask expressions in ASCII, so the separator value is a
  // char.
  const char separator = '|';

  // Accumulate the result by interpreting one word at a time, scanning
  // from left to right.
  uint32_t value = 0;
  const char* begin = textValue;  // The left end of the current word.
  const char* end = nullptr;  // One character past the end of the current word.
  do {
    end = std::find(begin, text_end, separator);

    spv_operand_desc entry = nullptr;
    if (spvOperandTableNameLookup(operandTable, type, begin, end - begin,
                                  &entry)) {
      return SPV_ERROR_INVALID_TEXT;
    }
    value |= entry->value;

    // Advance to the next word by skipping over the separator.
    begin = end + 1;
  } while (end != text_end);

  *pValue = value;
  return SPV_SUCCESS;
}

// Returns the operand table.
spv_operand_table GetDefaultOperandTable() {
  spv_operand_table result = nullptr;
  spvOperandTableGet(&result);
  assert(result);
  return result;
}

// Returns the opcode table.
spv_opcode_table GetDefaultOpcodeTable() {
  spv_opcode_table result = nullptr;
  spvOpcodeTableGet(&result);
  assert(result);
  return result;
}

// Returns the extended instruction table.
spv_ext_inst_table GetDefaultExtInstTable() {
  spv_ext_inst_table result = nullptr;
  spvExtInstTableGet(&result);
  assert(result);
  return result;
}

}  // anonymous namespace

namespace libspirv {

AssemblyGrammar::AssemblyGrammar()
    : AssemblyGrammar(GetDefaultOperandTable(), GetDefaultOpcodeTable(),
                      GetDefaultExtInstTable()) {
  assert(isValid());
}

bool AssemblyGrammar::isValid() const {
  return operandTable_ && opcodeTable_ && extInstTable_;
}

spv_result_t AssemblyGrammar::lookupOpcode(const char* name,
                                           spv_opcode_desc* desc) const {
  return spvOpcodeTableNameLookup(opcodeTable_, name, desc);
}

spv_result_t AssemblyGrammar::lookupOpcode(SpvOp opcode,
                                           spv_opcode_desc* desc) const {
  return spvOpcodeTableValueLookup(opcodeTable_, opcode, desc);
}

spv_result_t AssemblyGrammar::lookupOperand(spv_operand_type_t type,
                                            const char* name, size_t name_len,
                                            spv_operand_desc* desc) const {
  return spvOperandTableNameLookup(operandTable_, type, name, name_len, desc);
}

spv_result_t AssemblyGrammar::lookupOperand(spv_operand_type_t type,
                                            uint32_t operand,
                                            spv_operand_desc* desc) const {
  return spvOperandTableValueLookup(operandTable_, type, operand, desc);
}

spv_result_t AssemblyGrammar::parseMaskOperand(const spv_operand_type_t type,
                                               const char* textValue,
                                               uint32_t* pValue) const {
  return spvTextParseMaskOperand(operandTable_, type, textValue, pValue);
}
spv_result_t AssemblyGrammar::lookupExtInst(spv_ext_inst_type_t type,
                                            const char* textValue,
                                            spv_ext_inst_desc* extInst) const {
  return spvExtInstTableNameLookup(extInstTable_, type, textValue, extInst);
}

spv_result_t AssemblyGrammar::lookupExtInst(spv_ext_inst_type_t type,
                                            uint32_t firstWord,
                                            spv_ext_inst_desc* extInst) const {
  return spvExtInstTableValueLookup(extInstTable_, type, firstWord, extInst);
}

void AssemblyGrammar::prependOperandTypesForMask(
    const spv_operand_type_t type, const uint32_t mask,
    spv_operand_pattern_t* pattern) const {
  spvPrependOperandTypesForMask(operandTable_, type, mask, pattern);
}
}  // namespace libspirv