1 #include <ATen/core/TensorBody.h> 2 3 // TODO Undo all logic introduced for Note [Avoiding Include Cycles In Static Dispatch] 4 // Code introduced to avoid cyclic dependency in static dispatch is no longer 5 // needed as static dispatch logic is moved from TensorBody.h, which caused cycles in the first place, 6 // to Operators.cpp for supporting multiple backends with multiple kernels. 7 // 8 // Note [Avoiding Include Cycles In Static Dispatch] 9 // In order to avoid #include cycles in the static dispatch build, we've carefully split out 10 // the static function definition files into {DispatchKey}Functions.h and {DispatchKey}Functions_inl.h. 11 // 12 // Without this split, the include cycle looks like TensorBody.h -> CPUFunctions.h -> TensorBody.h. 13 // - TensorBody.h #includes CPUFunctions.h in the static dispatch build, because the tensor methods 14 // all need to call into the fastpath C++ API defined in CPUFunctions.h. The methods are also all 15 // directly inlined into TensorBody.h. 16 // - CPUFunctions.h #includes TensorBody.h because it contains function declarations for the entire C++ API, 17 // which include functions that have defaultable std::optional<Tensor> arguments. 18 // That requires knowing the full Tensor class definition. 19 // 20 // We break the cycle by doing the following: 21 // - Split out CPUFunction.h into two files: CPUFunctions.h and CPUFunctions_inl.h 22 // - CPUFunction.h is a dummy file that just includes the Tensor class and includes CPUFunctions_inl., 23 // - CPUFunctions_inl.h includes everything else 24 // - (only in the static dispatch build) TensorBody.h makes sure to finish defining the Tensor class, 25 // and then it includes CPUFunctions_inl.h. 26 // - All other files that want the cpu fastpath functions can include CPUFunctions.h directly. 27 // - This also means that static dispatch build, CPUFunctions.h only needs to 28 // #include TensorBody.h, and it will automatically bring in CPUFunctions_inl.h. 29 ${inline_headers} 30