Container Type Definition Format

This document describes the format of the container definition files contained in this directory.

info

type_name

The fully-qualified name of the container type. This is used to match against the names of types contained in an executable's debug information.
ctype

A reference to the enum ContainerTypeEnum in OI's source code.
header

The name of the C++ header file in which this container is defined.
stub_template_params

The indexes of template parameters which do not represent types stored within this container. These parameters will not be recursed into and measured by OI.
underlying_container_index

Only used for container adapters. Points OI to the template parameter representing the underlying container to be measured.

codegen

decl

C++ code for the declaration of a getSizeType function for this container.
func

C++ code for the definition of a getSizeType function for this container.
handler

C++ code for the definition of a TypeHandler class for this container. See further down for a description.

Changes introduced with Typed Data Segment

decl and func fields are ignored when using -ftyped-data-segment and the handler field is used instead.

TypeHandler Classes

A TypeHandler class describes both what a type will write into the data segment and how to write it. It consists of two major parts:

using type = ...; - describe what it will write into the data segment.
static types::st::Unit<DB> getSizeType(...) - a function which takes a const reference to a container and a ::type by value and fills in the type.

Example:

template <typename DB, typename T0>
struct TypeHandler<DB, std::string<T0>> {
  using type =
      types::st::Pair<DB, types::st::VarInt<DB>, types::st::VarInt<DB>>;

  static types::st::Unit<DB> getSizeType(
      const std::string<T0> & container,
      typename TypeHandler<DB, std::string<T0>>::type returnArg) {
    bool sso = ((uintptr_t)container.data() <
                (uintptr_t)(&container + sizeof(std::string<T0>))) &&
               ((uintptr_t)container.data() >= (uintptr_t)&container);

    return returnArg.write(container.capacity()).write(container.size());
  }
};

Changes introduced with TypeGraph

typeName and matcher fields have been merged into the single field type_name.
ns namespace definition is no longer required.
underlyingContainerIndex renamed to underlying_container_index
The options for measuring / stubbing / removing template parameters have been reworked:
- By default all parameters are now measured. This includes the tail parameters in a variadic template.
- There is one option to specify template parameters which should not be measured: stub_template_params. The type graph code will automatically determine what type of stubbing to apply to each parameter in this list.

Deprecated Options

numTemplateParams

The first numTemplateParams template parameters for this container represent the types for the data we want to process. If this is not set, use all a container's template parameters. All of a container's parameters will still be enumerated and output in CodeGen, regardless of this setting.
allocatorIndex

Index of a template parameter representing an allocator. It will be not be used when CodeGenning this container.
replaceTemplateParamIndex

Indexes of template parameters to be stubbed out, i.e. replaced with dummy structs of a given size. Used for custom hashers and comparers.

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