From 54742ce7263ec91d869e96196a7b51bcfae44835 Mon Sep 17 00:00:00 2001
From: Mukund Lakshman <yaymukund@gmail.com>
Date: Fri, 19 Mar 2021 23:22:39 +0000
Subject: [PATCH] Use serde's error message option to avoid implementing
 `Deserialize`.

---
 Cargo.toml                    |  2 +-
 src/cargo/util/toml/mod.rs    | 81 ++---------------------------------
 tests/testsuite/bad_config.rs |  4 +-
 3 files changed, 7 insertions(+), 80 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 85d99c1ae..32f1c839e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -52,7 +52,7 @@ percent-encoding = "2.0"
 rustfix = "0.5.0"
 same-file = "1"
 semver = { version = "0.10", features = ["serde"] }
-serde = { version = "1.0.82", features = ["derive"] }
+serde = { version = "1.0.123", features = ["derive"] }
 serde_ignored = "0.1.0"
 serde_json = { version = "1.0.30", features = ["raw_value"] }
 shell-escape = "0.1.4"
diff --git a/src/cargo/util/toml/mod.rs b/src/cargo/util/toml/mod.rs
index 7f7aadb4c..b0bf31736 100644
--- a/src/cargo/util/toml/mod.rs
+++ b/src/cargo/util/toml/mod.rs
@@ -419,53 +419,13 @@ impl ser::Serialize for TomlOptLevel {
     }
 }
 
-#[derive(Clone, Debug, Serialize, Eq, PartialEq)]
-#[serde(untagged)]
+#[derive(Clone, Debug, Deserialize, Serialize, Eq, PartialEq)]
+#[serde(untagged, expecting = "expected a boolean or an integer")]
 pub enum U32OrBool {
     U32(u32),
     Bool(bool),
 }
 
-impl<'de> de::Deserialize<'de> for U32OrBool {
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: de::Deserializer<'de>,
-    {
-        struct Visitor;
-
-        impl<'de> de::Visitor<'de> for Visitor {
-            type Value = U32OrBool;
-
-            fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-                formatter.write_str("a boolean or an integer")
-            }
-
-            fn visit_bool<E>(self, b: bool) -> Result<Self::Value, E>
-            where
-                E: de::Error,
-            {
-                Ok(U32OrBool::Bool(b))
-            }
-
-            fn visit_i64<E>(self, u: i64) -> Result<Self::Value, E>
-            where
-                E: de::Error,
-            {
-                Ok(U32OrBool::U32(u as u32))
-            }
-
-            fn visit_u64<E>(self, u: u64) -> Result<Self::Value, E>
-            where
-                E: de::Error,
-            {
-                Ok(U32OrBool::U32(u as u32))
-            }
-        }
-
-        deserializer.deserialize_any(Visitor)
-    }
-}
-
 #[derive(Deserialize, Serialize, Clone, Debug, Default, Eq, PartialEq)]
 #[serde(default, rename_all = "kebab-case")]
 pub struct TomlProfile {
@@ -770,46 +730,13 @@ impl<'de> de::Deserialize<'de> for StringOrVec {
     }
 }
 
-#[derive(Clone, Debug, Serialize, Eq, PartialEq)]
-#[serde(untagged)]
+#[derive(Clone, Debug, Deserialize, Serialize, Eq, PartialEq)]
+#[serde(untagged, expecting = "expected a boolean or a string")]
 pub enum StringOrBool {
     String(String),
     Bool(bool),
 }
 
-impl<'de> de::Deserialize<'de> for StringOrBool {
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: de::Deserializer<'de>,
-    {
-        struct Visitor;
-
-        impl<'de> de::Visitor<'de> for Visitor {
-            type Value = StringOrBool;
-
-            fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-                formatter.write_str("a boolean or a string")
-            }
-
-            fn visit_bool<E>(self, b: bool) -> Result<Self::Value, E>
-            where
-                E: de::Error,
-            {
-                Ok(StringOrBool::Bool(b))
-            }
-
-            fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
-            where
-                E: de::Error,
-            {
-                Ok(StringOrBool::String(s.to_string()))
-            }
-        }
-
-        deserializer.deserialize_any(Visitor)
-    }
-}
-
 #[derive(PartialEq, Clone, Debug, Serialize)]
 #[serde(untagged)]
 pub enum VecStringOrBool {
diff --git a/tests/testsuite/bad_config.rs b/tests/testsuite/bad_config.rs
index e7a6b01c0..2b598485a 100644
--- a/tests/testsuite/bad_config.rs
+++ b/tests/testsuite/bad_config.rs
@@ -1309,7 +1309,7 @@ fn bad_debuginfo() {
 error: failed to parse manifest at `[..]`
 
 Caused by:
-  invalid type: string \"a\", expected a boolean or an integer for [..]
+  expected a boolean or an integer for [..]
 ",
         )
         .run();
@@ -1338,7 +1338,7 @@ fn bad_opt_level() {
 error: failed to parse manifest at `[..]`
 
 Caused by:
-  invalid type: integer `3`, expected a boolean or a string for key [..]
+  expected a boolean or a string for key [..]
 ",
         )
         .run();