| // Copyright 2018 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include <lib/fidl/walker.h> |
| |
| #include <cstdint> |
| #include <limits> |
| |
| namespace fidl { |
| |
| zx_status_t PrimaryObjectSize(const fidl_type_t* type, uint32_t buffer_size, |
| uint32_t* out_primary_size, uint32_t* out_first_out_of_line, |
| const char** out_error) { |
| ZX_DEBUG_ASSERT(type != nullptr); |
| ZX_DEBUG_ASSERT(out_primary_size != nullptr); |
| ZX_DEBUG_ASSERT(out_first_out_of_line != nullptr); |
| auto set_error = [&out_error](const char* msg) { |
| if (out_error) |
| *out_error = msg; |
| }; |
| |
| // The struct case is "likely" because overhead for tables is less of a relative cost. |
| uint32_t primary_size; |
| if (likely(type->type_tag() == kFidlTypeStruct)) { |
| primary_size = type->coded_struct().size; |
| } else if (likely(type->type_tag() == kFidlTypeTable)) { |
| primary_size = sizeof(fidl_table_t); |
| } else { |
| set_error("Message must be a struct or a table"); |
| return ZX_ERR_INVALID_ARGS; |
| } |
| *out_primary_size = static_cast<uint32_t>(primary_size); |
| |
| uint64_t first_out_of_line = FidlAlign(static_cast<uint32_t>(primary_size)); |
| if (unlikely(first_out_of_line > buffer_size)) { |
| set_error("Buffer is too small for first inline object"); |
| return ZX_ERR_BUFFER_TOO_SMALL; |
| } |
| if (unlikely(first_out_of_line > std::numeric_limits<uint32_t>::max())) { |
| set_error("Out of line starting offset overflows"); |
| return ZX_ERR_INVALID_ARGS; |
| } |
| *out_first_out_of_line = static_cast<uint32_t>(first_out_of_line); |
| return ZX_OK; |
| } |
| |
| } // namespace fidl |
