onnx_pb.h

Central header that takes the role of the protobuf-generated onnx_pb.h in the standard ONNX package.

Why this file exists

In the standard onnx package every message class (ModelProto, TensorProto, etc.) is auto-generated by the protoc compiler from the ONNX .proto schema files, and the generated translation unit is named onnx_pb.h. That file is the single include point relied on by almost all ONNX C++ source files to pull in the message types and the ONNX_LIGHT_NAMESPACE / ONNX_API macros.

onnx-light eliminates the protobuf dependency entirely: message classes are hand-written in onnx_light/onnx/onnx_proto/onnx.h using a set of code-generation macros (BEGIN_PROTO, FIELD, etc.) defined in stream_class.h. This file acts as the drop-in replacement for the protobuf-generated onnx_pb.h; it includes the hand-crafted message types and provides the same namespace and export macros so that the rest of the ONNX C++ sources compile unchanged.

Defines

ONNX_NAMESPACE

Namespace used for all onnx-light C++ symbols.

Defaults to onnx_light. Can be overridden at compile time to allow onnx-light to coexist with the standard onnx library in the same translation unit.

Backwards-compatible alias so that code referencing ONNX_NAMESPACE (the macro used in the standard onnx package) resolves to the same namespace as ONNX_LIGHT_NAMESPACE.

ONNX_LIGHT_ONNX_NAMESPACE_ALIAS_DEFINED

namespace onnx_light

Alias that makes onnx-light headers compatible with code that references ONNX_LIGHT_NAMESPACE (the macro used in the standard onnx package).

Set to ONNX_LIGHT_NAMESPACE so both names resolve to the same namespace.

Symbol-visibility attribute for the public onnx-light C++ API.

Defined as empty because onnx-light does not require explicit __declspec(dllexport) or __attribute__((visibility("default"))) annotations — visibility is controlled at the shared-library level. The macro is provided so that vendored ONNX headers that decorate their declarations with ONNX_API compile without modification.

Namespace alias so that ONNX C++ code (and consumers such as onnxruntime) that refers to the literal onnx namespace — rather than the ONNX_NAMESPACE macro — resolves to the onnx-light namespace. The standard onnx package lives in namespace onnx; onnx-light uses onnx_light (via ONNX_LIGHT_NAMESPACE), so this alias keeps onnx-light a true drop-in. It is only introduced when the onnx-light namespace differs from onnx.