docs: expand importNative/exec example (#10803)

Co-authored-by: Qyriad <qyriad@qyriad.me>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
(cherry picked from commit 5786e1ae7c300b3c7434e7df99b41f180dc42e37)
Change-Id: I16b408ba7c70dca985c05c71bf6195fe9f0b5841
This commit is contained in:
Jörg Thalheim 2024-05-29 09:50:51 +02:00 committed by Jörg Thalheim
parent 71b32bb87c
commit 194b6cc611

View file

@ -15,9 +15,21 @@ struct EvalSettings : Config
static std::string resolvePseudoUrl(std::string_view url);
Setting<bool> enableNativeCode{this, false, "allow-unsafe-native-code-during-evaluation", R"(
Whether builtin functions that allow executing native code should be enabled.
Enable built-in functions that allow executing native code.
In particular, this adds the `importNative` and `exec` builtins.
In particular, this adds:
- `builtins.importNative` *path* *symbol*
Runs function with *symbol* from a dynamic shared object (DSO) at *path*.
This may be used to add new builtins to the Nix language.
The procedure must have the following signature:
```cpp
extern "C" typedef void (*ValueInitialiser) (EvalState & state, Value & v);
```
- `builtins.exec` *arguments*
Execute a program, where *arguments* are specified as a list of strings, and parse its output as a Nix expression.
)"};
Setting<Strings> nixPath{