From 87c102370e108479ff94ec3cb5d524da00fcedb0 Mon Sep 17 00:00:00 2001
From: Wolfgang Bumiller <w.bumiller@proxmox.com>
Date: Mon, 23 Nov 2020 15:51:50 +0100
Subject: [PATCH] add methods to 'bless' values

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
---
 perlmod/Cargo.toml   |  1 +
 perlmod/src/error.rs | 26 +++++++-------------------
 perlmod/src/ffi.rs   |  3 +++
 perlmod/src/glue.c   |  8 ++++++++
 perlmod/src/lib.rs   |  1 +
 perlmod/src/value.rs | 31 +++++++++++++++++++++++++++++++
 6 files changed, 51 insertions(+), 19 deletions(-)

diff --git a/perlmod/Cargo.toml b/perlmod/Cargo.toml
index 4e01bb6..1d41c15 100644
--- a/perlmod/Cargo.toml
+++ b/perlmod/Cargo.toml
@@ -19,6 +19,7 @@ bitflags = "1.2.1"
 libc = "0.2"
 perlmod-macro = { path = "../perlmod-macro", optional = true, version = "0.1" }
 serde = { version = "1.0", features = ["derive"] }
+thiserror = "1.0"
 
 [features]
 default = ["exporter"]
diff --git a/perlmod/src/error.rs b/perlmod/src/error.rs
index 51f567a..bc1e2bd 100644
--- a/perlmod/src/error.rs
+++ b/perlmod/src/error.rs
@@ -1,16 +1,12 @@
-#[derive(Debug)]
+use thiserror::Error as ThisError;
+
+#[derive(ThisError, Debug)]
+#[error("wrong type")]
 pub struct CastError;
 
-impl std::fmt::Display for CastError {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(f, "wrong type")
-    }
-}
-
-impl std::error::Error for CastError {}
-
-#[derive(Clone, Debug)]
-pub struct Error(String);
+#[derive(ThisError, Clone, Debug)]
+#[error("error: {0}")]
+pub struct Error(pub(crate) String);
 
 impl Error {
     #[inline]
@@ -24,14 +20,6 @@ impl Error {
     }
 }
 
-impl std::fmt::Display for Error {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(f, "error: {}", self.0)
-    }
-}
-
-impl std::error::Error for Error {}
-
 impl serde::de::Error for Error {
     fn custom<T: std::fmt::Display>(msg: T) -> Self {
         Self(msg.to_string())
diff --git a/perlmod/src/ffi.rs b/perlmod/src/ffi.rs
index ae4191a..cb673fb 100644
--- a/perlmod/src/ffi.rs
+++ b/perlmod/src/ffi.rs
@@ -91,6 +91,9 @@ extern "C" {
     pub fn RSPL_hv_iternext(hv: *mut HV) -> *mut HE;
     pub fn RSPL_hv_iterkeysv(he: *mut HE) -> *mut SV;
     pub fn RSPL_hv_iterval(hv: *mut HV, he: *mut HE) -> *mut SV;
+
+    pub fn RSPL_gv_stashsv(name: *const SV, flags: i32) -> *mut HV;
+    pub fn RSPL_sv_bless(sv: *mut SV, stash: *mut HV) -> *mut SV;
 }
 
 /// Argument marker for the stack.
diff --git a/perlmod/src/glue.c b/perlmod/src/glue.c
index a12f507..174e228 100644
--- a/perlmod/src/glue.c
+++ b/perlmod/src/glue.c
@@ -270,6 +270,14 @@ extern SV* RSPL_hv_iterval(HV *hv, HE *he) {
     return hv_iterval(hv, he);
 }
 
+extern HV* RSPL_gv_stashsv(SV *name, int32_t flags) {
+    return gv_stashsv(name, flags);
+}
+
+extern SV* RSPL_sv_bless(SV *sv, HV *stash) {
+    return sv_bless(sv, stash);
+}
+
 /*
 These make are convoluted brainfarts:
         SVt_NULL                 undef
diff --git a/perlmod/src/lib.rs b/perlmod/src/lib.rs
index c3ef620..d7b3aa0 100644
--- a/perlmod/src/lib.rs
+++ b/perlmod/src/lib.rs
@@ -14,6 +14,7 @@
 //! [`make_package!`]: macro.make_package.html
 
 pub(crate) mod error;
+pub use error::Error;
 
 pub mod de;
 pub mod ffi;
diff --git a/perlmod/src/value.rs b/perlmod/src/value.rs
index f85844b..ea26ce5 100644
--- a/perlmod/src/value.rs
+++ b/perlmod/src/value.rs
@@ -7,6 +7,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::ffi::{self, SV};
 use crate::scalar::ScalarRef;
+use crate::Error;
 use crate::{Array, Hash, Scalar};
 
 /// A higher level value. This is basically an `SV` already cast to `AV` or `HV` for arrays and
@@ -58,6 +59,36 @@ impl Value {
         Value::Reference(unsafe { Scalar::from_raw_move(ffi::RSPL_newRV_inc(value.sv())) })
     }
 
+    /// Bless a value into a package. This turns the value into a reference and forwards to
+    /// [`Value::bless_ref`].
+    pub fn bless_value(&self, package: &str) -> Result<Value, Error> {
+        self.clone_ref().bless_ref(package)
+    }
+
+    /// Bless a reference into a package. The `Value` must be a reference.
+    pub fn bless_ref(&self, package: &str) -> Result<Value, Error> {
+        let value = match self {
+            Value::Reference(v) => v,
+            _ => Error::fail("trying to bless a non-reference")?,
+        };
+
+        let pkgsv = Scalar::new_string(package);
+        let stash = unsafe { ffi::RSPL_gv_stashsv(pkgsv.sv(), 0) };
+        if stash.is_null() {
+            return Err(Error(format!("failed to find package {:?}", package)));
+        }
+
+        let value = unsafe { ffi::RSPL_sv_bless(value.sv(), stash) };
+        if value.is_null() {
+            return Err(Error(format!(
+                "failed to bless value into package {:?}",
+                package
+            )));
+        }
+
+        Ok(Value::Reference(unsafe { Scalar::from_raw_move(value) }))
+    }
+
     /// Take over a raw `SV` value, assuming that we then own a reference to it.
     ///
     /// # Safety