support sys::set_verbosity

nixide/src/verbosity.rs

@@ -1,4 +1,7 @@
+use crate::errors::ErrorContext;
 use crate::sys;
+use crate::util::wrappers::AsInnerPtr as _;
+use crate::util::{panic_issue, panic_issue_call_failed, wrap};
 
 /// Verbosity level
 ///
@@ -28,7 +31,46 @@ impl From<sys::nix_verbosity> for NixVerbosity {
             sys::nix_verbosity_NIX_LVL_CHATTY => NixVerbosity::Chatty,
             sys::nix_verbosity_NIX_LVL_DEBUG => NixVerbosity::Debug,
             sys::nix_verbosity_NIX_LVL_VOMIT => NixVerbosity::Vomit,
-            _ => panic!("nixide encountered unknown `nix_verbosity` value, please submit this as an issue at https://github.com/cry128/nixide"),
+            value => panic_issue!(
+                "nixide encountered unknown `nix_verbosity` value ({})",
+                value
+            ),
         }
     }
 }
+
+impl Into<sys::nix_verbosity> for NixVerbosity {
+    fn into(self) -> sys::nix_verbosity {
+        self as sys::nix_verbosity
+    }
+}
+
+/// Sets the verbosity level.
+///
+/// **This function should never fail!**
+/// A panic would indicate a bug in nixide itself.
+///
+/// # Nix C++ API Internals
+///
+/// ```cpp
+/// nix_err nix_set_verbosity(nix_c_context * context, nix_verbosity level)
+/// {
+///     if (context)
+///         context->last_err_code = NIX_OK;
+///     if (level > NIX_LVL_VOMIT || level < NIX_LVL_ERROR)
+///         return nix_set_err_msg(context, NIX_ERR_UNKNOWN, "Invalid verbosity level");
+///     try {
+///         nix::verbosity = static_cast<nix::Verbosity>(level);
+///     } catch (...) {
+///         return nix_context_error(context);
+///     }
+///     return NIX_OK;
+/// }
+/// ```
+///
+pub fn set_verbosity(level: NixVerbosity) {
+    wrap::nix_fn!(|ctx: &ErrorContext| unsafe {
+        sys::nix_set_verbosity(ctx.as_ptr(), level.into());
+    })
+    .unwrap_or_else(|err| panic_issue_call_failed!("{}", err))
+}