nix-super/src/libexpr/primops.hh
Robert Hensing 4e27f1947a libexpr: Reduce nonRecursiveStackReservation
128 is still beyond the point where the allocation overhead is
insignificant, but we don't anticipate to overflow for these
use cases, so it's fine.
2023-11-16 15:38:21 +01:00

54 lines
1.4 KiB
C++

#pragma once
///@file
#include "eval.hh"
#include <tuple>
#include <vector>
namespace nix {
/**
* For functions where we do not expect deep recursion, we can use a sizable
* part of the stack a free allocation space.
*
* Note: this is expected to be multiplied by sizeof(Value), or about 24 bytes.
*/
constexpr size_t nonRecursiveStackReservation = 128;
/**
* Functions that maybe applied to self-similar inputs, such as concatMap on a
* tree, should reserve a smaller part of the stack for allocation.
*
* Note: this is expected to be multiplied by sizeof(Value), or about 24 bytes.
*/
constexpr size_t conservativeStackReservation = 16;
struct RegisterPrimOp
{
typedef std::vector<PrimOp> PrimOps;
static PrimOps * primOps;
/**
* You can register a constant by passing an arity of 0. fun
* will get called during EvalState initialization, so there
* may be primops not yet added and builtins is not yet sorted.
*/
RegisterPrimOp(PrimOp && primOp);
};
/* These primops are disabled without enableNativeCode, but plugins
may wish to use them in limited contexts without globally enabling
them. */
/**
* Load a ValueInitializer from a DSO and return whatever it initializes
*/
void prim_importNative(EvalState & state, const PosIdx pos, Value * * args, Value & v);
/**
* Execute a program and parse its output
*/
void prim_exec(EvalState & state, const PosIdx pos, Value * * args, Value & v);
}