Replace serde's derive with custom proc macro

This replaces the existing `Deserialize` derive from serde with a
`ConfigDeserialize` derive. The goal of this new proc macro is to allow
a more error-friendly deserialization for the Alacritty configuration
file without having to manage a lot of boilerplate code inside the
configuration modules.

The first part of the derive macro is for struct deserialization. This
takes structs which have `Default` implemented and will only replace
fields which can be successfully deserialized. Otherwise the `log` crate
is used for printing errors. Since this deserialization takes the
default value from the struct instead of the value, it removes the
necessity for creating new types just to implement `Default` on them for
deserialization.

Additionally, the struct deserialization also checks for `Option` values
and makes sure that explicitly specifying `none` as text literal is
allowed for all options.

The other part of the derive macro is responsible for deserializing
enums. While only enums with Unit variants are supported, it will
automatically implement a deserializer for these enums which accepts any
form of capitalization.

Since this custom derive prevents us from using serde's attributes on
fields, some of the attributes have been reimplemented for
`ConfigDeserialize`. These include `#[config(flatten)]`,
`#[config(skip)]` and `#[config(alias = "alias)]`. The flatten attribute
is currently limited to at most one per struct.

Additionally the `#[config(deprecated = "optional message")]` attribute
allows easily defining uniform deprecation messages for fields on
structs.

Author: chrisduerr

Diff for: CHANGELOG.md

@@ -21,6 +21,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Changed
 
 - Nonexistent config imports are ignored instead of raising an error
+- Value for disabling logging with `config.log_level` is `Off` instead of `None`
 
 ### Fixed
 
@@ -51,6 +52,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
     * `--dimensions`
     * `--position`
 - `live-shader-reload` feature
+- Config option `dynamic_title`, you should use `window.dynamic_title` instead
+- Config option `scrolling.faux_multiplier`, which was replaced by escape `CSI ? 1007 h/l`
 
 ## 0.6.0
 

Diff for: Cargo.lock

@@ -2,6 +2,7 @@
 members = [
     "alacritty",
     "alacritty_terminal",
+    "alacritty_config_derive",
 ]
 
 [profile.release]

Diff for: Cargo.toml

@@ -799,7 +799,7 @@
   # Log level
   #
   # Values for `log_level`:
-  #   - None
+  #   - Off
   #   - Error
   #   - Warn
   #   - Info

Diff for: alacritty.yml

@@ -13,9 +13,13 @@ path = "../alacritty_terminal"
 version = "0.11.1-dev"
 default-features = false
 
+[dependencies.alacritty_config_derive]
+path = "../alacritty_config_derive"
+version = "0.1.0"
+
 [dependencies]
 clap = "2"
-log = { version = "0.4", features = ["std"] }
+log = { version = "0.4", features = ["std", "serde"] }
 time = "0.1.40"
 fnv = "1"
 serde = { version = "1", features = ["derive"] }

Diff for: alacritty/Cargo.toml

@@ -230,13 +230,17 @@ impl Options {
 
         config.hold = self.hold;
 
-        let dynamic_title = config.ui_config.dynamic_title() && self.title.is_none();
-        config.ui_config.set_dynamic_title(dynamic_title);
-
-        replace_if_some(&mut config.ui_config.window.title, self.title.clone());
-        replace_if_some(&mut config.ui_config.window.class.instance, self.class_instance.clone());
-        replace_if_some(&mut config.ui_config.window.class.general, self.class_general.clone());
+        if let Some(title) = self.title.clone() {
+            config.ui_config.window.title = title
+        }
+        if let Some(class_instance) = self.class_instance.clone() {
+            config.ui_config.window.class.instance = class_instance;
+        }
+        if let Some(class_general) = self.class_general.clone() {
+            config.ui_config.window.class.general = class_general;
+        }
 
+        config.ui_config.window.dynamic_title &= self.title.is_none();
         config.ui_config.window.embed = self.embed.as_ref().and_then(|embed| embed.parse().ok());
         config.ui_config.debug.print_events |= self.print_events;
         config.ui_config.debug.log_level = max(config.ui_config.debug.log_level, self.log_level);
@@ -249,12 +253,6 @@ impl Options {
     }
 }
 
-fn replace_if_some<T>(option: &mut T, value: Option<T>) {
-    if let Some(value) = value {
-        *option = value;
-    }
-}
-
 /// Format an option in the format of `parent.field=value` to a serde Value.
 fn option_as_value(option: &str) -> Result<Value, serde_yaml::Error> {
     let mut yaml_text = String::with_capacity(option.len());
@@ -289,11 +287,11 @@ mod tests {
     #[test]
     fn dynamic_title_ignoring_options_by_default() {
         let mut config = Config::default();
-        let old_dynamic_title = config.ui_config.dynamic_title();
+        let old_dynamic_title = config.ui_config.window.dynamic_title;
 
         Options::default().override_config(&mut config);
 
-        assert_eq!(old_dynamic_title, config.ui_config.dynamic_title());
+        assert_eq!(old_dynamic_title, config.ui_config.window.dynamic_title);
     }
 
     #[test]
@@ -304,7 +302,7 @@ mod tests {
         options.title = Some("foo".to_owned());
         options.override_config(&mut config);
 
-        assert!(!config.ui_config.dynamic_title());
+        assert!(!config.ui_config.window.dynamic_title);
     }
 
     #[test]
@@ -314,7 +312,7 @@ mod tests {
         config.ui_config.window.title = "foo".to_owned();
         Options::default().override_config(&mut config);
 
-        assert!(config.ui_config.dynamic_title());
+        assert!(config.ui_config.window.dynamic_title);
     }
 
     #[test]

Diff for: alacritty/src/cli.rs

@@ -10,6 +10,8 @@ use serde::de::{self, MapAccess, Unexpected, Visitor};
 use serde::{Deserialize, Deserializer};
 use serde_yaml::Value as SerdeValue;
 
+use alacritty_config_derive::ConfigDeserialize;
+
 use alacritty_terminal::config::Program;
 use alacritty_terminal::term::TermMode;
 use alacritty_terminal::vi_mode::ViMotion;
@@ -79,26 +81,26 @@ impl<T: Eq> Binding<T> {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[derive(ConfigDeserialize, Debug, Clone, PartialEq, Eq)]
 pub enum Action {
     /// Write an escape sequence.
-    #[serde(skip)]
+    #[config(skip)]
     Esc(String),
 
     /// Run given command.
-    #[serde(skip)]
+    #[config(skip)]
     Command(Program),
 
     /// Move vi mode cursor.
-    #[serde(skip)]
+    #[config(skip)]
     ViMotion(ViMotion),
 
     /// Perform vi mode action.
-    #[serde(skip)]
+    #[config(skip)]
     ViAction(ViAction),
 
     /// Perform search mode action.
-    #[serde(skip)]
+    #[config(skip)]
     SearchAction(SearchAction),
 
     /// Paste contents of system clipboard.
@@ -227,7 +229,7 @@ impl Display for Action {
 }
 
 /// Vi mode specific actions.
-#[derive(Deserialize, Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(ConfigDeserialize, Debug, Copy, Clone, PartialEq, Eq)]
 pub enum ViAction {
     /// Toggle normal vi selection.
     ToggleNormalSelection,
@@ -912,7 +914,7 @@ impl<'a> Deserialize<'a> for RawBinding {
                     where
                         E: de::Error,
                     {
-                        match value {
+                        match value.to_ascii_lowercase().as_str() {
                             "key" => Ok(Field::Key),
                             "mods" => Ok(Field::Mods),
                             "mode" => Ok(Field::Mode),

Diff for: alacritty/src/config/bindings.rs

@@ -1,64 +1,33 @@
-use log::{error, LevelFilter};
-use serde::{Deserialize, Deserializer};
+use log::LevelFilter;
 
-use alacritty_terminal::config::{failure_default, LOG_TARGET_CONFIG};
+use alacritty_config_derive::ConfigDeserialize;
 
 /// Debugging options.
-#[serde(default)]
-#[derive(Deserialize, Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(ConfigDeserialize, Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct Debug {
-    #[serde(default = "default_log_level", deserialize_with = "deserialize_log_level")]
     pub log_level: LevelFilter,
 
-    #[serde(deserialize_with = "failure_default")]
     pub print_events: bool,
 
     /// Keep the log file after quitting.
-    #[serde(deserialize_with = "failure_default")]
     pub persistent_logging: bool,
 
     /// Should show render timer.
-    #[serde(deserialize_with = "failure_default")]
     pub render_timer: bool,
 
     /// Record ref test.
-    #[serde(skip)]
+    #[config(skip)]
     pub ref_test: bool,
 }
 
 impl Default for Debug {
     fn default() -> Self {
         Self {
-            log_level: default_log_level(),
+            log_level: LevelFilter::Warn,
             print_events: Default::default(),
             persistent_logging: Default::default(),
             render_timer: Default::default(),
             ref_test: Default::default(),
         }
     }
 }
-
-fn default_log_level() -> LevelFilter {
-    LevelFilter::Warn
-}
-
-fn deserialize_log_level<'a, D>(deserializer: D) -> Result<LevelFilter, D::Error>
-where
-    D: Deserializer<'a>,
-{
-    Ok(match failure_default::<D, String>(deserializer)?.to_lowercase().as_str() {
-        "off" | "none" => LevelFilter::Off,
-        "error" => LevelFilter::Error,
-        "warn" => LevelFilter::Warn,
-        "info" => LevelFilter::Info,
-        "debug" => LevelFilter::Debug,
-        "trace" => LevelFilter::Trace,
-        level => {
-            error!(
-                target: LOG_TARGET_CONFIG,
-                "Problem with config: invalid log level {}; using level Warn", level
-            );
-            default_log_level()
-        },
-    })
-}