From c1a0f49e9f92ce7ebb8c9f2a3baefce779bb5950 Mon Sep 17 00:00:00 2001
From: Pietro Albini <pietro.albini@ferrous-systems.com>
Date: Tue, 7 Jun 2022 12:17:11 +0200
Subject: [PATCH 1/7] keep the same config values in stage0 between invocations

This commit allows users to change the contents of the "config" key in
src/stage0.json without having it overridden the next time the
bump-stage0 tool is executed.
---
 src/bootstrap/bootstrap.py        |  2 +-
 src/stage0.json                   |  4 ++-
 src/tools/bump-stage0/src/main.rs | 45 ++++++++++++++++++-------------
 3 files changed, 31 insertions(+), 20 deletions(-)

diff --git a/src/bootstrap/bootstrap.py b/src/bootstrap/bootstrap.py
index 635e4f3703b1c..3b2b507b06237 100644
--- a/src/bootstrap/bootstrap.py
+++ b/src/bootstrap/bootstrap.py
@@ -1043,7 +1043,7 @@ def bootstrap(help_triggered):
     build.checksums_sha256 = data["checksums_sha256"]
     build.stage0_compiler = Stage0Toolchain(data["compiler"])
 
-    build.set_dist_environment(data["dist_server"])
+    build.set_dist_environment(data["config"]["dist_server"])
 
     build.build = args.build or build.build_triple()
 
diff --git a/src/stage0.json b/src/stage0.json
index 6371b9eae599e..5af6d7d824f22 100644
--- a/src/stage0.json
+++ b/src/stage0.json
@@ -1,6 +1,8 @@
 {
   "__comment": "Generated by `./x.py run src/tools/bump-stage0`. Run that command again to update the bootstrap compiler.",
-  "dist_server": "https://static.rust-lang.org",
+  "config": {
+    "dist_server": "https://static.rust-lang.org"
+  },
   "compiler": {
     "date": "2022-05-20",
     "version": "beta"
diff --git a/src/tools/bump-stage0/src/main.rs b/src/tools/bump-stage0/src/main.rs
index d6364e28fef97..e9ae1fe272f29 100644
--- a/src/tools/bump-stage0/src/main.rs
+++ b/src/tools/bump-stage0/src/main.rs
@@ -4,11 +4,12 @@ use indexmap::IndexMap;
 use std::collections::HashMap;
 use std::convert::TryInto;
 
-const DIST_SERVER: &str = "https://static.rust-lang.org";
+const PATH: &str = "src/stage0.json";
 const COMPILER_COMPONENTS: &[&str] = &["rustc", "rust-std", "cargo"];
 const RUSTFMT_COMPONENTS: &[&str] = &["rustfmt-preview"];
 
 struct Tool {
+    config: Config,
     channel: Channel,
     version: [u16; 3],
     checksums: IndexMap<String, String>,
@@ -32,18 +33,20 @@ impl Tool {
             .try_into()
             .map_err(|_| anyhow::anyhow!("failed to parse version"))?;
 
-        Ok(Self { channel, version, checksums: IndexMap::new() })
+        let existing: Stage0 = serde_json::from_slice(&std::fs::read(PATH)?)?;
+
+        Ok(Self { channel, version, config: existing.config, checksums: IndexMap::new() })
     }
 
     fn update_json(mut self) -> Result<(), Error> {
         std::fs::write(
-            "src/stage0.json",
+            PATH,
             format!(
                 "{}\n",
                 serde_json::to_string_pretty(&Stage0 {
                     comment: "Generated by `./x.py run src/tools/bump-stage0`. \
-                              Run that command again to update the bootstrap compiler.",
-                    dist_server: DIST_SERVER.into(),
+                              Run that command again to update the bootstrap compiler."
+                        .into(),
                     compiler: self.detect_compiler()?,
                     rustfmt: self.detect_rustfmt()?,
                     checksums_sha256: {
@@ -51,7 +54,8 @@ impl Tool {
                         // are added while filling the other struct fields just above this block.
                         self.checksums.sort_keys();
                         self.checksums
-                    }
+                    },
+                    config: self.config,
                 })?
             ),
         )?;
@@ -74,7 +78,7 @@ impl Tool {
             Channel::Nightly => "beta".to_string(),
         };
 
-        let manifest = fetch_manifest(&channel)?;
+        let manifest = fetch_manifest(&self.config, &channel)?;
         self.collect_checksums(&manifest, COMPILER_COMPONENTS)?;
         Ok(Stage0Toolchain {
             date: manifest.date,
@@ -100,13 +104,13 @@ impl Tool {
             return Ok(None);
         }
 
-        let manifest = fetch_manifest("nightly")?;
+        let manifest = fetch_manifest(&self.config, "nightly")?;
         self.collect_checksums(&manifest, RUSTFMT_COMPONENTS)?;
         Ok(Some(Stage0Toolchain { date: manifest.date, version: "nightly".into() }))
     }
 
     fn collect_checksums(&mut self, manifest: &Manifest, components: &[&str]) -> Result<(), Error> {
-        let prefix = format!("{}/", DIST_SERVER);
+        let prefix = format!("{}/", self.config.dist_server);
         for component in components {
             let pkg = manifest
                 .pkg
@@ -136,10 +140,10 @@ fn main() -> Result<(), Error> {
     Ok(())
 }
 
-fn fetch_manifest(channel: &str) -> Result<Manifest, Error> {
+fn fetch_manifest(config: &Config, channel: &str) -> Result<Manifest, Error> {
     Ok(toml::from_slice(&http_get(&format!(
         "{}/dist/channel-rust-{}.toml",
-        DIST_SERVER, channel
+        config.dist_server, channel
     ))?)?)
 }
 
@@ -166,35 +170,40 @@ enum Channel {
     Nightly,
 }
 
-#[derive(Debug, serde::Serialize)]
+#[derive(Debug, serde::Serialize, serde::Deserialize)]
 struct Stage0 {
     #[serde(rename = "__comment")]
-    comment: &'static str,
-    dist_server: String,
+    comment: String,
+    config: Config,
     compiler: Stage0Toolchain,
     rustfmt: Option<Stage0Toolchain>,
     checksums_sha256: IndexMap<String, String>,
 }
 
-#[derive(Debug, serde::Serialize)]
+#[derive(Debug, serde::Serialize, serde::Deserialize)]
+struct Config {
+    dist_server: String,
+}
+
+#[derive(Debug, serde::Serialize, serde::Deserialize)]
 struct Stage0Toolchain {
     date: String,
     version: String,
 }
 
-#[derive(Debug, serde::Deserialize)]
+#[derive(Debug, serde::Serialize, serde::Deserialize)]
 struct Manifest {
     date: String,
     pkg: HashMap<String, ManifestPackage>,
 }
 
-#[derive(Debug, serde::Deserialize)]
+#[derive(Debug, serde::Serialize, serde::Deserialize)]
 struct ManifestPackage {
     version: String,
     target: HashMap<String, ManifestTargetPackage>,
 }
 
-#[derive(Debug, serde::Deserialize)]
+#[derive(Debug, serde::Serialize, serde::Deserialize)]
 struct ManifestTargetPackage {
     url: Option<String>,
     hash: Option<String>,

From 97f3ecda016ca7ab3edf64e11901466f879d4483 Mon Sep 17 00:00:00 2001
From: Pietro Albini <pietro.albini@ferrous-systems.com>
Date: Tue, 7 Jun 2022 13:15:41 +0200
Subject: [PATCH 2/7] load configuration for downloading artifacts from
 stage0.json

---
 src/bootstrap/builder.rs          | 10 ++----
 src/bootstrap/config.rs           | 60 ++++++++++++++++++++++---------
 src/bootstrap/lib.rs              | 19 ----------
 src/bootstrap/native.rs           | 15 ++++----
 src/stage0.json                   |  5 ++-
 src/tools/bump-stage0/src/main.rs |  3 ++
 6 files changed, 62 insertions(+), 50 deletions(-)

diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index 38d4f15d3c858..abd99233e0c7b 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -870,16 +870,10 @@ impl<'a> Builder<'a> {
         self.try_run(patchelf.arg(fname));
     }
 
-    pub(crate) fn download_component(
-        &self,
-        base: &str,
-        url: &str,
-        dest_path: &Path,
-        help_on_error: &str,
-    ) {
+    pub(crate) fn download_component(&self, url: &str, dest_path: &Path, help_on_error: &str) {
         // Use a temporary file in case we crash while downloading, to avoid a corrupt download in cache/.
         let tempfile = self.tempdir().join(dest_path.file_name().unwrap());
-        self.download_with_retries(&tempfile, &format!("{}/{}", base, url), help_on_error);
+        self.download_with_retries(&tempfile, url, help_on_error);
         t!(std::fs::rename(&tempfile, dest_path));
     }
 
diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index 99b69ee9a4fd1..76d95851d3fa6 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -20,7 +20,6 @@ use crate::channel::GitInfo;
 pub use crate::flags::Subcommand;
 use crate::flags::{Color, Flags};
 use crate::util::{exe, output, program_out_of_date, t};
-use crate::RustfmtMetadata;
 use once_cell::sync::OnceCell;
 use serde::{Deserialize, Deserializer};
 
@@ -73,6 +72,7 @@ pub struct Config {
     pub test_compare_mode: bool,
     pub color: Color,
     pub patch_binaries_for_nix: bool,
+    pub stage0_metadata: Stage0Metadata,
 
     pub on_fail: Option<String>,
     pub stage: u32,
@@ -720,6 +720,25 @@ define_config! {
     }
 }
 
+#[derive(Default, Deserialize)]
+pub struct Stage0Metadata {
+    pub config: Stage0Config,
+    pub checksums_sha256: HashMap<String, String>,
+    pub rustfmt: Option<RustfmtMetadata>,
+}
+#[derive(Default, Deserialize)]
+pub struct Stage0Config {
+    pub dist_server: String,
+    pub artifacts_server: String,
+    pub artifacts_with_llvm_assertions_server: String,
+    pub git_merge_commit_email: String,
+}
+#[derive(Default, Deserialize)]
+pub struct RustfmtMetadata {
+    pub date: String,
+    pub version: String,
+}
+
 impl Config {
     pub fn default_opts() -> Config {
         let mut config = Config::default();
@@ -776,6 +795,9 @@ impl Config {
         config.llvm_profile_use = flags.llvm_profile_use;
         config.llvm_profile_generate = flags.llvm_profile_generate;
 
+        let stage0_json = t!(std::fs::read(&config.src.join("src").join("stage0.json")));
+        config.stage0_metadata = t!(serde_json::from_slice::<Stage0Metadata>(&stage0_json));
+
         #[cfg(test)]
         let get_toml = |_| TomlConfig::default();
         #[cfg(not(test))]
@@ -1103,8 +1125,11 @@ impl Config {
             config.rust_codegen_units_std = rust.codegen_units_std.map(threads_from_config);
             config.rust_profile_use = flags.rust_profile_use.or(rust.profile_use);
             config.rust_profile_generate = flags.rust_profile_generate.or(rust.profile_generate);
-            config.download_rustc_commit =
-                download_ci_rustc_commit(rust.download_rustc, config.verbose > 0);
+            config.download_rustc_commit = download_ci_rustc_commit(
+                &config.stage0_metadata,
+                rust.download_rustc,
+                config.verbose > 0,
+            );
         } else {
             config.rust_profile_use = flags.rust_profile_use;
             config.rust_profile_generate = flags.rust_profile_generate;
@@ -1424,7 +1449,11 @@ fn threads_from_config(v: u32) -> u32 {
 }
 
 /// Returns the commit to download, or `None` if we shouldn't download CI artifacts.
-fn download_ci_rustc_commit(download_rustc: Option<StringOrBool>, verbose: bool) -> Option<String> {
+fn download_ci_rustc_commit(
+    stage0_metadata: &Stage0Metadata,
+    download_rustc: Option<StringOrBool>,
+    verbose: bool,
+) -> Option<String> {
     // If `download-rustc` is not set, default to rebuilding.
     let if_unchanged = match download_rustc {
         None | Some(StringOrBool::Bool(false)) => return None,
@@ -1443,13 +1472,12 @@ fn download_ci_rustc_commit(download_rustc: Option<StringOrBool>, verbose: bool)
 
     // Look for a version to compare to based on the current commit.
     // Only commits merged by bors will have CI artifacts.
-    let merge_base = output(Command::new("git").args(&[
-        "rev-list",
-        "--author=bors@rust-lang.org",
-        "-n1",
-        "--first-parent",
-        "HEAD",
-    ]));
+    let merge_base = output(
+        Command::new("git")
+            .arg("rev-list")
+            .arg(format!("--author={}", stage0_metadata.config.git_merge_commit_email))
+            .args(&["-n1", "--first-parent", "HEAD"]),
+    );
     let commit = merge_base.trim_end();
     if commit.is_empty() {
         println!("error: could not find commit hash for downloading rustc");
@@ -1484,7 +1512,7 @@ fn download_ci_rustc_commit(download_rustc: Option<StringOrBool>, verbose: bool)
 }
 
 fn maybe_download_rustfmt(builder: &Builder<'_>) -> Option<PathBuf> {
-    let RustfmtMetadata { date, version } = builder.stage0_metadata.rustfmt.as_ref()?;
+    let RustfmtMetadata { date, version } = builder.config.stage0_metadata.rustfmt.as_ref()?;
     let channel = format!("{version}-{date}");
 
     let host = builder.config.build;
@@ -1568,13 +1596,13 @@ fn download_component(
     let tarball = cache_dir.join(&filename);
     let (base_url, url, should_verify) = match mode {
         DownloadSource::CI => (
-            "https://ci-artifacts.rust-lang.org/rustc-builds".to_string(),
+            builder.config.stage0_metadata.config.artifacts_server.clone(),
             format!("{key}/{filename}"),
             false,
         ),
         DownloadSource::Dist => {
             let dist_server = env::var("RUSTUP_DIST_SERVER")
-                .unwrap_or(builder.stage0_metadata.dist_server.to_string());
+                .unwrap_or(builder.config.stage0_metadata.config.dist_server.to_string());
             // NOTE: make `dist` part of the URL because that's how it's stored in src/stage0.json
             (dist_server, format!("dist/{key}/{filename}"), true)
         }
@@ -1590,7 +1618,7 @@ fn download_component(
             target at this time, see https://doc.rust-lang.org/nightly\
             /rustc/platform-support.html for more information."
         );
-        let sha256 = builder.stage0_metadata.checksums_sha256.get(&url).expect(&error);
+        let sha256 = builder.config.stage0_metadata.checksums_sha256.get(&url).expect(&error);
         if tarball.exists() {
             if builder.verify(&tarball, sha256) {
                 builder.unpack(&tarball, &bin_root, prefix);
@@ -1610,7 +1638,7 @@ fn download_component(
         None
     };
 
-    builder.download_component(&base_url, &url, &tarball, "");
+    builder.download_component(&format!("{base_url}/{url}"), &tarball, "");
     if let Some(sha256) = checksum {
         if !builder.verify(&tarball, sha256) {
             panic!("failed to verify {}", tarball.display());
diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index 022f2e0fc1387..c4a1d603b67ef 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -118,7 +118,6 @@ use std::os::windows::fs::symlink_file;
 
 use filetime::FileTime;
 use once_cell::sync::OnceCell;
-use serde::Deserialize;
 
 use crate::builder::Kind;
 use crate::config::{LlvmLibunwind, TargetSelection};
@@ -294,8 +293,6 @@ pub struct Build {
     hosts: Vec<TargetSelection>,
     targets: Vec<TargetSelection>,
 
-    // Stage 0 (downloaded) compiler, lld and cargo or their local rust equivalents
-    stage0_metadata: Stage0Metadata,
     initial_rustc: PathBuf,
     initial_cargo: PathBuf,
     initial_lld: PathBuf,
@@ -322,18 +319,6 @@ pub struct Build {
     metrics: metrics::BuildMetrics,
 }
 
-#[derive(Deserialize)]
-struct Stage0Metadata {
-    dist_server: String,
-    checksums_sha256: HashMap<String, String>,
-    rustfmt: Option<RustfmtMetadata>,
-}
-#[derive(Deserialize)]
-struct RustfmtMetadata {
-    date: String,
-    version: String,
-}
-
 #[derive(Debug)]
 struct Crate {
     name: Interned<String>,
@@ -482,11 +467,7 @@ impl Build {
             bootstrap_out
         };
 
-        let stage0_json = t!(std::fs::read_to_string(&src.join("src").join("stage0.json")));
-        let stage0_metadata = t!(serde_json::from_str::<Stage0Metadata>(&stage0_json));
-
         let mut build = Build {
-            stage0_metadata,
             initial_rustc: config.initial_rustc.clone(),
             initial_cargo: config.initial_cargo.clone(),
             initial_lld,
diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs
index 79f2338b7abb9..e21aa65618b05 100644
--- a/src/bootstrap/native.rs
+++ b/src/bootstrap/native.rs
@@ -121,7 +121,7 @@ pub(crate) fn maybe_download_ci_llvm(builder: &Builder<'_>) {
     let mut rev_list = Command::new("git");
     rev_list.args(&[
         PathBuf::from("rev-list"),
-        "--author=bors@rust-lang.org".into(),
+        format!("--author={}", builder.config.stage0_metadata.config.git_merge_commit_email).into(),
         "-n1".into(),
         "--first-parent".into(),
         "HEAD".into(),
@@ -170,11 +170,10 @@ fn download_ci_llvm(builder: &Builder<'_>, llvm_sha: &str) {
     if !rustc_cache.exists() {
         t!(fs::create_dir_all(&rustc_cache));
     }
-    let base = "https://ci-artifacts.rust-lang.org";
-    let url = if llvm_assertions {
-        format!("rustc-builds-alt/{}", llvm_sha)
+    let base = if llvm_assertions {
+        &builder.config.stage0_metadata.config.artifacts_with_llvm_assertions_server
     } else {
-        format!("rustc-builds/{}", llvm_sha)
+        &builder.config.stage0_metadata.config.artifacts_server
     };
     let filename = format!("rust-dev-nightly-{}.tar.xz", builder.build.build.triple);
     let tarball = rustc_cache.join(&filename);
@@ -187,7 +186,11 @@ fn download_ci_llvm(builder: &Builder<'_>, llvm_sha: &str) {
 \ndownload-ci-llvm = false
 \n
 ";
-        builder.download_component(base, &format!("{}/{}", url, filename), &tarball, help_on_error);
+        builder.download_component(
+            &format!("{base}/{llvm_sha}/{filename}"),
+            &tarball,
+            help_on_error,
+        );
     }
     let llvm_root = builder.config.ci_llvm_root();
     builder.unpack(&tarball, &llvm_root, "rust-dev");
diff --git a/src/stage0.json b/src/stage0.json
index 5af6d7d824f22..b178295528339 100644
--- a/src/stage0.json
+++ b/src/stage0.json
@@ -1,7 +1,10 @@
 {
   "__comment": "Generated by `./x.py run src/tools/bump-stage0`. Run that command again to update the bootstrap compiler.",
   "config": {
-    "dist_server": "https://static.rust-lang.org"
+    "dist_server": "https://static.rust-lang.org",
+    "artifacts_server": "https://ci-artifacts.rust-lang.org/rustc-builds",
+    "artifacts_with_llvm_assertions_server": "https://ci-artifacts.rust-lang.org/rustc-builds-alt",
+    "git_merge_commit_email": "bors@rust-lang.org"
   },
   "compiler": {
     "date": "2022-05-20",
diff --git a/src/tools/bump-stage0/src/main.rs b/src/tools/bump-stage0/src/main.rs
index e9ae1fe272f29..b40fd66e08eb8 100644
--- a/src/tools/bump-stage0/src/main.rs
+++ b/src/tools/bump-stage0/src/main.rs
@@ -183,6 +183,9 @@ struct Stage0 {
 #[derive(Debug, serde::Serialize, serde::Deserialize)]
 struct Config {
     dist_server: String,
+    artifacts_server: String,
+    artifacts_with_llvm_assertions_server: String,
+    git_merge_commit_email: String,
 }
 
 #[derive(Debug, serde::Serialize, serde::Deserialize)]

From 77097c5da87338e4964b8a717466beb2346f480c Mon Sep 17 00:00:00 2001
From: Pietro Albini <pietro.albini@ferrous-systems.com>
Date: Tue, 7 Jun 2022 13:29:39 +0200
Subject: [PATCH 3/7] change stage0.json to reduce the chance of merge
 conflicts

---
 src/stage0.json                   | 11 ++++++++++-
 src/tools/bump-stage0/src/main.rs | 27 +++++++++++++++++++++------
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/stage0.json b/src/stage0.json
index b178295528339..b6b502f4cf0cb 100644
--- a/src/stage0.json
+++ b/src/stage0.json
@@ -1,11 +1,20 @@
 {
-  "__comment": "Generated by `./x.py run src/tools/bump-stage0`. Run that command again to update the bootstrap compiler.",
   "config": {
     "dist_server": "https://static.rust-lang.org",
     "artifacts_server": "https://ci-artifacts.rust-lang.org/rustc-builds",
     "artifacts_with_llvm_assertions_server": "https://ci-artifacts.rust-lang.org/rustc-builds-alt",
     "git_merge_commit_email": "bors@rust-lang.org"
   },
+  "__comments": [
+    "The configuration above this comment is editable, and can be changed",
+    "by forks of the repository if they have alternate values.",
+    "",
+    "The section below is generated by `./x.py run src/tools/bump-stage0`,",
+    "run that command again to update the bootstrap compiler.",
+    "",
+    "All changes below this comment will be overridden the next time the",
+    "tool is executed."
+  ],
   "compiler": {
     "date": "2022-05-20",
     "version": "beta"
diff --git a/src/tools/bump-stage0/src/main.rs b/src/tools/bump-stage0/src/main.rs
index b40fd66e08eb8..7c6e4bb4fb5be 100644
--- a/src/tools/bump-stage0/src/main.rs
+++ b/src/tools/bump-stage0/src/main.rs
@@ -10,6 +10,8 @@ const RUSTFMT_COMPONENTS: &[&str] = &["rustfmt-preview"];
 
 struct Tool {
     config: Config,
+    comments: Vec<String>,
+
     channel: Channel,
     version: [u16; 3],
     checksums: IndexMap<String, String>,
@@ -35,7 +37,13 @@ impl Tool {
 
         let existing: Stage0 = serde_json::from_slice(&std::fs::read(PATH)?)?;
 
-        Ok(Self { channel, version, config: existing.config, checksums: IndexMap::new() })
+        Ok(Self {
+            channel,
+            version,
+            config: existing.config,
+            comments: existing.comments,
+            checksums: IndexMap::new(),
+        })
     }
 
     fn update_json(mut self) -> Result<(), Error> {
@@ -44,9 +52,6 @@ impl Tool {
             format!(
                 "{}\n",
                 serde_json::to_string_pretty(&Stage0 {
-                    comment: "Generated by `./x.py run src/tools/bump-stage0`. \
-                              Run that command again to update the bootstrap compiler."
-                        .into(),
                     compiler: self.detect_compiler()?,
                     rustfmt: self.detect_rustfmt()?,
                     checksums_sha256: {
@@ -56,6 +61,7 @@ impl Tool {
                         self.checksums
                     },
                     config: self.config,
+                    comments: self.comments,
                 })?
             ),
         )?;
@@ -172,9 +178,18 @@ enum Channel {
 
 #[derive(Debug, serde::Serialize, serde::Deserialize)]
 struct Stage0 {
-    #[serde(rename = "__comment")]
-    comment: String,
     config: Config,
+    // Comments are explicitly below the config, do not move them above.
+    //
+    // Downstream forks of the compiler codebase can change the configuration values defined above,
+    // but doing so would risk merge conflicts whenever they import new changes that include a
+    // bootstrap compiler bump.
+    //
+    // To lessen the pain, a big block of comments is placed between the configuration and the
+    // auto-generated parts of the file, preventing git diffs of the config to include parts of the
+    // auto-egenrated content and vice versa. This should prevent merge conflicts.
+    #[serde(rename = "__comments")]
+    comments: Vec<String>,
     compiler: Stage0Toolchain,
     rustfmt: Option<Stage0Toolchain>,
     checksums_sha256: IndexMap<String, String>,

From 2f44813511277b6d15dc993bd79e7432dec334e1 Mon Sep 17 00:00:00 2001
From: Pietro Albini <pietro.albini@ferrous-systems.com>
Date: Tue, 7 Jun 2022 14:50:14 +0200
Subject: [PATCH 4/7] future-proof adding more protocols

---
 src/bootstrap/builder.rs | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index abd99233e0c7b..7b74c5ccdbb0e 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -873,11 +873,20 @@ impl<'a> Builder<'a> {
     pub(crate) fn download_component(&self, url: &str, dest_path: &Path, help_on_error: &str) {
         // Use a temporary file in case we crash while downloading, to avoid a corrupt download in cache/.
         let tempfile = self.tempdir().join(dest_path.file_name().unwrap());
-        self.download_with_retries(&tempfile, url, help_on_error);
+        // While bootstrap itself only supports http and https downloads, downstream forks might
+        // need to download components from other protocols. The match allows them adding more
+        // protocols without worrying about merge conficts if we change the HTTP implementation.
+        match url.split_once("://").map(|(proto, _)| proto) {
+            Some("http") | Some("https") => {
+                self.download_http_with_retries(&tempfile, url, help_on_error)
+            }
+            Some(other) => panic!("unsupported protocol {other} in {url}"),
+            None => panic!("no protocol in {url}"),
+        }
         t!(std::fs::rename(&tempfile, dest_path));
     }
 
-    fn download_with_retries(&self, tempfile: &Path, url: &str, help_on_error: &str) {
+    fn download_http_with_retries(&self, tempfile: &Path, url: &str, help_on_error: &str) {
         println!("downloading {}", url);
         // Try curl. If that fails and we are on windows, fallback to PowerShell.
         let mut curl = Command::new("curl");

From 754af72ba7997638d6a8437b6968fa8372a1655e Mon Sep 17 00:00:00 2001
From: Pietro Albini <pietro@pietroalbini.org>
Date: Tue, 7 Jun 2022 15:34:32 +0200
Subject: [PATCH 5/7] fix typo

Co-authored-by: bjorn3 <bjorn3@users.noreply.github.com>
---
 src/tools/bump-stage0/src/main.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tools/bump-stage0/src/main.rs b/src/tools/bump-stage0/src/main.rs
index 7c6e4bb4fb5be..1c839fdc00a08 100644
--- a/src/tools/bump-stage0/src/main.rs
+++ b/src/tools/bump-stage0/src/main.rs
@@ -187,7 +187,7 @@ struct Stage0 {
     //
     // To lessen the pain, a big block of comments is placed between the configuration and the
     // auto-generated parts of the file, preventing git diffs of the config to include parts of the
-    // auto-egenrated content and vice versa. This should prevent merge conflicts.
+    // auto-generated content and vice versa. This should prevent merge conflicts.
     #[serde(rename = "__comments")]
     comments: Vec<String>,
     compiler: Stage0Toolchain,

From c20541f8324fdb9b91f3eb11f38cdbdf1aa40f17 Mon Sep 17 00:00:00 2001
From: Pietro Albini <pietro.albini@ferrous-systems.com>
Date: Fri, 10 Jun 2022 09:31:23 +0200
Subject: [PATCH 6/7] fix tests

---
 src/bootstrap/config.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index 76d95851d3fa6..cb89a98f75c3b 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -721,12 +721,14 @@ define_config! {
 }
 
 #[derive(Default, Deserialize)]
+#[cfg_attr(test, derive(Clone))]
 pub struct Stage0Metadata {
     pub config: Stage0Config,
     pub checksums_sha256: HashMap<String, String>,
     pub rustfmt: Option<RustfmtMetadata>,
 }
 #[derive(Default, Deserialize)]
+#[cfg_attr(test, derive(Clone))]
 pub struct Stage0Config {
     pub dist_server: String,
     pub artifacts_server: String,
@@ -734,6 +736,7 @@ pub struct Stage0Config {
     pub git_merge_commit_email: String,
 }
 #[derive(Default, Deserialize)]
+#[cfg_attr(test, derive(Clone))]
 pub struct RustfmtMetadata {
     pub date: String,
     pub version: String,

From d3b15329f9f7c4c8c5b395a0362281255cde68f7 Mon Sep 17 00:00:00 2001
From: Pietro Albini <pietro.albini@ferrous-systems.com>
Date: Mon, 13 Jun 2022 10:23:50 +0200
Subject: [PATCH 7/7] move stage0 config closer to Config

---
 src/bootstrap/config.rs | 44 ++++++++++++++++++++---------------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index cb89a98f75c3b..819831a2283e4 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -212,6 +212,28 @@ pub struct Config {
     pub out: PathBuf,
 }
 
+#[derive(Default, Deserialize)]
+#[cfg_attr(test, derive(Clone))]
+pub struct Stage0Metadata {
+    pub config: Stage0Config,
+    pub checksums_sha256: HashMap<String, String>,
+    pub rustfmt: Option<RustfmtMetadata>,
+}
+#[derive(Default, Deserialize)]
+#[cfg_attr(test, derive(Clone))]
+pub struct Stage0Config {
+    pub dist_server: String,
+    pub artifacts_server: String,
+    pub artifacts_with_llvm_assertions_server: String,
+    pub git_merge_commit_email: String,
+}
+#[derive(Default, Deserialize)]
+#[cfg_attr(test, derive(Clone))]
+pub struct RustfmtMetadata {
+    pub date: String,
+    pub version: String,
+}
+
 #[derive(Clone, Debug)]
 pub enum RustfmtState {
     SystemToolchain(PathBuf),
@@ -720,28 +742,6 @@ define_config! {
     }
 }
 
-#[derive(Default, Deserialize)]
-#[cfg_attr(test, derive(Clone))]
-pub struct Stage0Metadata {
-    pub config: Stage0Config,
-    pub checksums_sha256: HashMap<String, String>,
-    pub rustfmt: Option<RustfmtMetadata>,
-}
-#[derive(Default, Deserialize)]
-#[cfg_attr(test, derive(Clone))]
-pub struct Stage0Config {
-    pub dist_server: String,
-    pub artifacts_server: String,
-    pub artifacts_with_llvm_assertions_server: String,
-    pub git_merge_commit_email: String,
-}
-#[derive(Default, Deserialize)]
-#[cfg_attr(test, derive(Clone))]
-pub struct RustfmtMetadata {
-    pub date: String,
-    pub version: String,
-}
-
 impl Config {
     pub fn default_opts() -> Config {
         let mut config = Config::default();