refactor(config): Move TOML file reading methods to 'toml' submodule

This commit moves the `Config` struct's methods responsible for reading and
deserializing `bootstrap.toml` files into `TomlConfig` instances to
`src/bootstrap/config/toml/mod.rs`.

Specifically, `Config::get_builder_toml`, `Config::get_toml`, and
`Config::get_toml_inner` are now located within the `toml` submodule.

Author: Shourya742

src/bootstrap/src/core/config/config.rs

@@ -17,7 +17,6 @@ use std::{env, fs};
 use build_helper::ci::CiEnv;
 use build_helper::exit;
 use build_helper::git::{GitConfig, PathFreshness, check_path_modifications, output_result};
-use serde::Deserialize;
 #[cfg(feature = "tracing")]
 use tracing::{instrument, span};
 
@@ -26,13 +25,12 @@ use crate::core::build_steps::llvm::LLVM_INVALIDATION_PATHS;
 use crate::core::config::flags::Color;
 pub use crate::core::config::flags::Subcommand;
 use crate::core::config::parsing::check_incompatible_options_for_ci_rustc;
-use crate::core::config::toml::change_id::{ChangeId, ChangeIdWrapper};
+use crate::core::config::toml::change_id::ChangeId;
 use crate::core::config::toml::common::{
     DebuginfoLevel, LlvmLibunwind, SplitDebuginfo, StringOrBool,
 };
 use crate::core::config::toml::rust::{LldMode, RustOptimize};
 use crate::core::config::toml::target::Target;
-use crate::core::config::toml::*;
 use crate::core::config::types::{DryRun, GccCiMode, RustcLto};
 use crate::core::download::is_download_ci_available;
 use crate::utils::channel;
@@ -58,14 +56,6 @@ pub const RUSTC_IF_UNCHANGED_ALLOWED_PATHS: &[&str] = &[
     ":!triagebot.toml",
 ];
 
-/// This file is embedded in the overlay directory of the tarball sources. It is
-/// useful in scenarios where developers want to see how the tarball sources were
-/// generated.
-///
-/// We also use this file to compare the host's bootstrap.toml against the CI rustc builder
-/// configuration to detect any incompatible options.
-pub const BUILDER_CONFIG_FILENAME: &str = "builder-config";
-
 /// Global configuration for the entire build and/or bootstrap.
 ///
 /// This structure is parsed from `bootstrap.toml`, and some of the fields are inferred from `git` or build-time parameters.
@@ -358,47 +348,6 @@ impl Config {
         Self::parse_inner(flags, Self::get_toml)
     }
 
-    pub(crate) fn get_builder_toml(&self, build_name: &str) -> Result<TomlConfig, toml::de::Error> {
-        if self.dry_run() {
-            return Ok(TomlConfig::default());
-        }
-
-        let builder_config_path =
-            self.out.join(self.build.triple).join(build_name).join(BUILDER_CONFIG_FILENAME);
-        Self::get_toml(&builder_config_path)
-    }
-
-    pub(crate) fn get_toml(file: &Path) -> Result<TomlConfig, toml::de::Error> {
-        #[cfg(test)]
-        return Ok(TomlConfig::default());
-
-        #[cfg(not(test))]
-        Self::get_toml_inner(file)
-    }
-
-    pub(crate) fn get_toml_inner(file: &Path) -> Result<TomlConfig, toml::de::Error> {
-        let contents =
-            t!(fs::read_to_string(file), format!("config file {} not found", file.display()));
-        // Deserialize to Value and then TomlConfig to prevent the Deserialize impl of
-        // TomlConfig and sub types to be monomorphized 5x by toml.
-        toml::from_str(&contents)
-            .and_then(|table: toml::Value| TomlConfig::deserialize(table))
-            .inspect_err(|_| {
-                if let Ok(ChangeIdWrapper { inner: Some(ChangeId::Id(id)) }) =
-                    toml::from_str::<toml::Value>(&contents)
-                        .and_then(|table: toml::Value| ChangeIdWrapper::deserialize(table))
-                {
-                    let changes = crate::find_recent_config_change_ids(id);
-                    if !changes.is_empty() {
-                        println!(
-                            "WARNING: There have been changes to x.py since you last updated:\n{}",
-                            crate::human_readable_changes(changes)
-                        );
-                    }
-                }
-            })
-    }
-
     pub fn dry_run(&self) -> bool {
         match self.dry_run {
             DryRun::Disabled => false,

src/bootstrap/src/core/config/mod.rs

@@ -10,6 +10,7 @@ pub mod types;
 
 pub use config::*;
 pub use target_selection::TargetSelection;
+pub use toml::BUILDER_CONFIG_FILENAME;
 pub use toml::change_id::ChangeId;
 pub use toml::common::*;
 pub use toml::rust::LldMode;

src/bootstrap/src/core/config/toml/mod.rs

@@ -6,6 +6,7 @@
 //! It also houses the `Merge` trait and `define_config!` macro, which are essential
 //! for handling these raw TOML structures.
 
+use serde::Deserialize;
 use serde_derive::Deserialize;
 pub mod build;
 pub mod change_id;
@@ -20,7 +21,7 @@ pub mod rust;
 pub mod target;
 
 use build::Build;
-use change_id::ChangeIdWrapper;
+use change_id::{ChangeId, ChangeIdWrapper};
 use dist::Dist;
 use gcc::Gcc;
 use install::Install;
@@ -30,7 +31,7 @@ use rust::Rust;
 use target::TomlTarget;
 
 use crate::core::config::toml::common::ReplaceOpt;
-use crate::{Config, HashMap, HashSet, PathBuf, exit};
+use crate::{Config, HashMap, HashSet, Path, PathBuf, exit, fs, t};
 
 /// Structure of the `bootstrap.toml` file that configuration is read from.
 ///
@@ -133,3 +134,54 @@ impl Merge for TomlConfig {
         }
     }
 }
+
+/// This file is embedded in the overlay directory of the tarball sources. It is
+/// useful in scenarios where developers want to see how the tarball sources were
+/// generated.
+///
+/// We also use this file to compare the host's bootstrap.toml against the CI rustc builder
+/// configuration to detect any incompatible options.
+pub const BUILDER_CONFIG_FILENAME: &str = "builder-config";
+
+impl Config {
+    pub(crate) fn get_builder_toml(&self, build_name: &str) -> Result<TomlConfig, toml::de::Error> {
+        if self.dry_run() {
+            return Ok(TomlConfig::default());
+        }
+
+        let builder_config_path =
+            self.out.join(self.build.triple).join(build_name).join(BUILDER_CONFIG_FILENAME);
+        Self::get_toml(&builder_config_path)
+    }
+
+    pub(crate) fn get_toml(file: &Path) -> Result<TomlConfig, toml::de::Error> {
+        #[cfg(test)]
+        return Ok(TomlConfig::default());
+
+        #[cfg(not(test))]
+        Self::get_toml_inner(file)
+    }
+
+    pub(crate) fn get_toml_inner(file: &Path) -> Result<TomlConfig, toml::de::Error> {
+        let contents =
+            t!(fs::read_to_string(file), format!("config file {} not found", file.display()));
+        // Deserialize to Value and then TomlConfig to prevent the Deserialize impl of
+        // TomlConfig and sub types to be monomorphized 5x by toml.
+        toml::from_str(&contents)
+            .and_then(|table: toml::Value| TomlConfig::deserialize(table))
+            .inspect_err(|_| {
+                if let Ok(ChangeIdWrapper { inner: Some(ChangeId::Id(id)) }) =
+                    toml::from_str::<toml::Value>(&contents)
+                        .and_then(|table: toml::Value| ChangeIdWrapper::deserialize(table))
+                {
+                    let changes = crate::find_recent_config_change_ids(id);
+                    if !changes.is_empty() {
+                        println!(
+                            "WARNING: There have been changes to x.py since you last updated:\n{}",
+                            crate::human_readable_changes(changes)
+                        );
+                    }
+                }
+            })
+    }
+}