Rollup merge of rust-lang#144807 - Shourya742:2025-07-30-streamline-config, r=Kobzol

Streamline config in bootstrap

This PR restructures the config module to improve readability and debuggability. It also aims to eliminate as many invariants as possible. Best reviewed commit by commit.

r? ````@Kobzol````

Author: Zalathar

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

@@ -7,11 +7,12 @@
 
 use serde::{Deserialize, Deserializer};
 
+use crate::core::config::Merge;
 use crate::core::config::toml::ReplaceOpt;
-use crate::core::config::{Merge, set};
-use crate::{Config, HashSet, PathBuf, define_config, exit};
+use crate::{HashSet, PathBuf, define_config, exit};
 
 define_config! {
+    #[derive(Default)]
     struct Dist {
         sign_folder: Option<String> = "sign-folder",
         upload_addr: Option<String> = "upload-addr",
@@ -22,31 +23,3 @@ define_config! {
         vendor: Option<bool> = "vendor",
     }
 }
-
-impl Config {
-    /// Applies distribution-related configuration from the `Dist` struct
-    /// to the global `Config` structure.
-    pub fn apply_dist_config(&mut self, toml_dist: Option<Dist>) {
-        if let Some(dist) = toml_dist {
-            let Dist {
-                sign_folder,
-                upload_addr,
-                src_tarball,
-                compression_formats,
-                compression_profile,
-                include_mingw_linker,
-                vendor,
-            } = dist;
-            self.dist_sign_folder = sign_folder.map(PathBuf::from);
-            self.dist_upload_addr = upload_addr;
-            self.dist_compression_formats = compression_formats;
-            set(&mut self.dist_compression_profile, compression_profile);
-            set(&mut self.rust_dist_src, src_tarball);
-            set(&mut self.dist_include_mingw_linker, include_mingw_linker);
-            self.dist_vendor = vendor.unwrap_or_else(|| {
-                // If we're building from git or tarball sources, enable it by default.
-                self.rust_info.is_managed_git_subrepository() || self.rust_info.is_from_tarball()
-            });
-        }
-    }
-}

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

@@ -6,29 +6,14 @@
 
 use serde::{Deserialize, Deserializer};
 
+use crate::core::config::Merge;
 use crate::core::config::toml::ReplaceOpt;
-use crate::core::config::{GccCiMode, Merge};
-use crate::{Config, HashSet, PathBuf, define_config, exit};
+use crate::{HashSet, PathBuf, define_config, exit};
 
 define_config! {
     /// TOML representation of how the GCC build is configured.
+    #[derive(Default)]
     struct Gcc {
         download_ci_gcc: Option<bool> = "download-ci-gcc",
     }
 }
-
-impl Config {
-    /// Applies GCC-related configuration from the `TomlGcc` struct to the
-    /// global `Config` structure.
-    pub fn apply_gcc_config(&mut self, toml_gcc: Option<Gcc>) {
-        if let Some(gcc) = toml_gcc {
-            self.gcc_ci_mode = match gcc.download_ci_gcc {
-                Some(value) => match value {
-                    true => GccCiMode::DownloadFromCi,
-                    false => GccCiMode::BuildLocally,
-                },
-                None => GccCiMode::default(),
-            };
-        }
-    }
-}

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

@@ -8,12 +8,13 @@
 
 use serde::{Deserialize, Deserializer};
 
+use crate::core::config::Merge;
 use crate::core::config::toml::ReplaceOpt;
-use crate::core::config::{Merge, set};
-use crate::{Config, HashSet, PathBuf, define_config, exit};
+use crate::{HashSet, PathBuf, define_config, exit};
 
 define_config! {
     /// TOML representation of various global install decisions.
+    #[derive(Default)]
     struct Install {
         prefix: Option<String> = "prefix",
         sysconfdir: Option<String> = "sysconfdir",
@@ -24,20 +25,3 @@ define_config! {
         datadir: Option<String> = "datadir",
     }
 }
-
-impl Config {
-    /// Applies installation-related configuration from the `Install` struct
-    /// to the global `Config` structure.
-    pub fn apply_install_config(&mut self, toml_install: Option<Install>) {
-        if let Some(install) = toml_install {
-            let Install { prefix, sysconfdir, docdir, bindir, libdir, mandir, datadir } = install;
-            self.prefix = prefix.map(PathBuf::from);
-            self.sysconfdir = sysconfdir.map(PathBuf::from);
-            self.datadir = datadir.map(PathBuf::from);
-            self.docdir = docdir.map(PathBuf::from);
-            set(&mut self.bindir, bindir.map(PathBuf::from));
-            self.libdir = libdir.map(PathBuf::from);
-            self.mandir = mandir.map(PathBuf::from);
-        }
-    }
-}

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

@@ -3,12 +3,13 @@
 
 use serde::{Deserialize, Deserializer};
 
+use crate::core::config::StringOrBool;
 use crate::core::config::toml::{Merge, ReplaceOpt, TomlConfig};
-use crate::core::config::{StringOrBool, set};
-use crate::{Config, HashMap, HashSet, PathBuf, define_config, exit};
+use crate::{HashMap, HashSet, PathBuf, define_config, exit};
 
 define_config! {
     /// TOML representation of how the LLVM build is configured.
+    #[derive(Default)]
     struct Llvm {
         optimize: Option<bool> = "optimize",
         thin_lto: Option<bool> = "thin-lto",
@@ -144,127 +145,3 @@ pub fn check_incompatible_options_for_ci_llvm(
 
     Ok(())
 }
-
-impl Config {
-    pub fn apply_llvm_config(&mut self, toml_llvm: Option<Llvm>) {
-        let mut llvm_tests = None;
-        let mut llvm_enzyme = None;
-        let mut llvm_offload = None;
-        let mut llvm_plugins = None;
-
-        if let Some(llvm) = toml_llvm {
-            let Llvm {
-                optimize: optimize_toml,
-                thin_lto,
-                release_debuginfo,
-                assertions: _,
-                tests,
-                enzyme,
-                plugins,
-                static_libstdcpp,
-                libzstd,
-                ninja,
-                targets,
-                experimental_targets,
-                link_jobs,
-                link_shared,
-                version_suffix,
-                clang_cl,
-                cflags,
-                cxxflags,
-                ldflags,
-                use_libcxx,
-                use_linker,
-                allow_old_toolchain,
-                offload,
-                polly,
-                clang,
-                enable_warnings,
-                download_ci_llvm,
-                build_config,
-            } = llvm;
-
-            set(&mut self.ninja_in_file, ninja);
-            llvm_tests = tests;
-            llvm_enzyme = enzyme;
-            llvm_offload = offload;
-            llvm_plugins = plugins;
-            set(&mut self.llvm_optimize, optimize_toml);
-            set(&mut self.llvm_thin_lto, thin_lto);
-            set(&mut self.llvm_release_debuginfo, release_debuginfo);
-            set(&mut self.llvm_static_stdcpp, static_libstdcpp);
-            set(&mut self.llvm_libzstd, libzstd);
-            if let Some(v) = link_shared {
-                self.llvm_link_shared.set(Some(v));
-            }
-            self.llvm_targets.clone_from(&targets);
-            self.llvm_experimental_targets.clone_from(&experimental_targets);
-            self.llvm_link_jobs = link_jobs;
-            self.llvm_version_suffix.clone_from(&version_suffix);
-            self.llvm_clang_cl.clone_from(&clang_cl);
-
-            self.llvm_cflags.clone_from(&cflags);
-            self.llvm_cxxflags.clone_from(&cxxflags);
-            self.llvm_ldflags.clone_from(&ldflags);
-            set(&mut self.llvm_use_libcxx, use_libcxx);
-            self.llvm_use_linker.clone_from(&use_linker);
-            self.llvm_allow_old_toolchain = allow_old_toolchain.unwrap_or(false);
-            self.llvm_offload = offload.unwrap_or(false);
-            self.llvm_polly = polly.unwrap_or(false);
-            self.llvm_clang = clang.unwrap_or(false);
-            self.llvm_enable_warnings = enable_warnings.unwrap_or(false);
-            self.llvm_build_config = build_config.clone().unwrap_or(Default::default());
-
-            self.llvm_from_ci = self.parse_download_ci_llvm(download_ci_llvm, self.llvm_assertions);
-
-            if self.llvm_from_ci {
-                let warn = |option: &str| {
-                    println!(
-                        "WARNING: `{option}` will only be used on `compiler/rustc_llvm` build, not for the LLVM build."
-                    );
-                    println!(
-                        "HELP: To use `{option}` for LLVM builds, set `download-ci-llvm` option to false."
-                    );
-                };
-
-                if static_libstdcpp.is_some() {
-                    warn("static-libstdcpp");
-                }
-
-                if link_shared.is_some() {
-                    warn("link-shared");
-                }
-
-                // FIXME(#129153): instead of all the ad-hoc `download-ci-llvm` checks that follow,
-                // use the `builder-config` present in tarballs since #128822 to compare the local
-                // config to the ones used to build the LLVM artifacts on CI, and only notify users
-                // if they've chosen a different value.
-
-                if libzstd.is_some() {
-                    println!(
-                        "WARNING: when using `download-ci-llvm`, the local `llvm.libzstd` option, \
-                        like almost all `llvm.*` options, will be ignored and set by the LLVM CI \
-                        artifacts builder config."
-                    );
-                    println!(
-                        "HELP: To use `llvm.libzstd` for LLVM/LLD builds, set `download-ci-llvm` option to false."
-                    );
-                }
-            }
-
-            if !self.llvm_from_ci && self.llvm_thin_lto && link_shared.is_none() {
-                // If we're building with ThinLTO on, by default we want to link
-                // to LLVM shared, to avoid re-doing ThinLTO (which happens in
-                // the link step) with each stage.
-                self.llvm_link_shared.set(Some(true));
-            }
-        } else {
-            self.llvm_from_ci = self.parse_download_ci_llvm(None, false);
-        }
-
-        self.llvm_tests = llvm_tests.unwrap_or(false);
-        self.llvm_enzyme = llvm_enzyme.unwrap_or(false);
-        self.llvm_offload = llvm_offload.unwrap_or(false);
-        self.llvm_plugins = llvm_plugins.unwrap_or(false);
-    }
-}

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

@@ -5,7 +5,7 @@
 //! these raw TOML configurations from various sources (the main `bootstrap.toml`,
 //! included files, profile defaults, and command-line overrides). This processed
 //! TOML data then serves as an intermediate representation, which is further
-//! transformed and applied to the final [`Config`] struct.
+//! transformed and applied to the final `Config` struct.
 
 use serde::Deserialize;
 use serde_derive::Deserialize;