Function CapabilityCheck

source/val/validate_instruction.cpp:242–274

Returns SPV_ERROR_INVALID_CAPABILITY and emits a diagnostic if the instruction is invalid because the required capability isn't declared in the module.

// instruction is invalid because the required capability isn't declared
// in the module.
spv_result_t CapabilityCheck(ValidationState_t& _, const Instruction* inst) {
  const spv::Op opcode = inst->opcode();
  CapabilitySet opcode_caps = EnablingCapabilitiesForOp(_, opcode);
  if (!_.HasAnyOfCapabilities(opcode_caps)) {
    return _.diag(SPV_ERROR_INVALID_CAPABILITY, inst)
           << "Opcode " << spvOpcodeString(opcode)
           << " requires one of these capabilities: " << ToString(opcode_caps);
  }
  for (size_t i = 0; i < inst->operands().size(); ++i) {
    const auto& operand = inst->operand(i);
    const auto word = inst->word(operand.offset);
    if (spvOperandIsConcreteMask(operand.type)) {
      // Check for required capabilities for each bit position of the mask.
      for (uint32_t mask_bit = 0x80000000; mask_bit; mask_bit >>= 1) {
        if (word & mask_bit) {
          spv_result_t status =
              CheckRequiredCapabilities(_, inst, i + 1, operand, mask_bit);
          if (status != SPV_SUCCESS) return status;
        }
      }
    } else if (spvIsIdType(operand.type)) {
      // TODO(dneto): Check the value referenced by this Id, if we can compute
      // it.  For now, just punt, to fix issue 248:
      // https://github.com/KhronosGroup/SPIRV-Tools/issues/248
    } else {
      // Check the operand word as a whole.
      spv_result_t status =
          CheckRequiredCapabilities(_, inst, i + 1, operand, word);
      if (status != SPV_SUCCESS) return status;
    }
  }
  return SPV_SUCCESS;
}

// Checks that the instruction can be used in this target environment's base
// version. Assumes that CapabilityCheck has checked direct capability