add rcs support to cargo-new|init

RCS is a venerable version control system available in many UNIX systems for
local version tracking. Adds support for initializing an RCS repo and
discovering it as an existing version control system.

Author: worr

src/cargo/ops/cargo_new.rs

@@ -1,7 +1,7 @@
 use crate::core::{Edition, Shell, Workspace};
 use crate::util::errors::CargoResult;
 use crate::util::important_paths::find_root_manifest_for_wd;
-use crate::util::{existing_vcs_repo, FossilRepo, GitRepo, HgRepo, PijulRepo};
+use crate::util::{existing_vcs_repo, FossilRepo, GitRepo, HgRepo, PijulRepo, RcsRepo};
 use crate::util::{restricted_names, GlobalContext};
 use anyhow::{anyhow, Context as _};
 use cargo_util::paths::{self, write_atomic};
@@ -22,6 +22,7 @@ pub enum VersionControl {
     Hg,
     Pijul,
     Fossil,
+    Rcs,
     NoVcs,
 }
 
@@ -34,6 +35,7 @@ impl FromStr for VersionControl {
             "hg" => Ok(VersionControl::Hg),
             "pijul" => Ok(VersionControl::Pijul),
             "fossil" => Ok(VersionControl::Fossil),
+            "rcs" => Ok(VersionControl::Rcs),
             "none" => Ok(VersionControl::NoVcs),
             other => anyhow::bail!("unknown vcs specification: `{}`", other),
         }
@@ -542,11 +544,16 @@ pub fn init(opts: &NewOptions, gctx: &GlobalContext) -> CargoResult<NewProjectKi
             num_detected_vcses += 1;
         }
 
+        if path.join("RCS").exists() {
+            version_control = Some(VersionControl::Rcs);
+            num_detected_vcses += 1;
+        }
+
         // if none exists, maybe create git, like in `cargo new`
 
         if num_detected_vcses > 1 {
             anyhow::bail!(
-                "more than one of .hg, .git, .pijul, .fossil configurations \
+                "more than one of .hg, .git, .pijul, .fossil, RCS configurations \
                  found and the ignore file can't be filled in as \
                  a result. specify --vcs to override detection"
             );
@@ -688,7 +695,7 @@ fn write_ignore_file(base_path: &Path, list: &IgnoreList, vcs: VersionControl) -
             base_path.join(".fossil-settings/ignore-glob"),
             base_path.join(".fossil-settings/clean-glob"),
         ],
-        VersionControl::NoVcs => return Ok(()),
+        VersionControl::Rcs | VersionControl::NoVcs => return Ok(()),
     } {
         let ignore: String = match paths::open(&fp_ignore) {
             Err(err) => match err.downcast_ref::<std::io::Error>() {
@@ -731,6 +738,11 @@ fn init_vcs(path: &Path, vcs: VersionControl, gctx: &GlobalContext) -> CargoResu
                 FossilRepo::init(path, gctx.cwd())?;
             }
         }
+        VersionControl::Rcs => {
+            if !path.join("RCS").exists() {
+                RcsRepo::init(path, gctx.cwd())?;
+            }
+        }
         VersionControl::NoVcs => {
             paths::create_dir_all(path)?;
         }
@@ -914,6 +926,10 @@ mod tests {
         );
     }
 
+    if vcs == VersionControl::Rcs {
+        RcsRepo::late_init(path)?;
+    }
+
     gctx.shell().note(
         "see more `Cargo.toml` keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html",
     )?;

src/cargo/util/command_prelude.rs

@@ -403,7 +403,7 @@ pub trait CommandExt: Sized {
                  a global configuration.",
             )
             .value_name("VCS")
-            .value_parser(["git", "hg", "pijul", "fossil", "none"]),
+            .value_parser(["git", "hg", "pijul", "fossil", "rcs", "none"]),
         )
         ._arg(
             flag("bin", "Use a binary (application) template [default]")
@@ -906,6 +906,7 @@ Run `{cmd}` to see possible targets."
             "hg" => VersionControl::Hg,
             "pijul" => VersionControl::Pijul,
             "fossil" => VersionControl::Fossil,
+            "rcs" => VersionControl::Rcs,
             "none" => VersionControl::NoVcs,
             vcs => panic!("Impossible vcs: {:?}", vcs),
         });

src/cargo/util/mod.rs

@@ -22,7 +22,7 @@ pub use self::progress::{Progress, ProgressStyle};
 pub use self::queue::Queue;
 pub use self::rustc::Rustc;
 pub use self::semver_ext::{OptVersionReq, VersionExt};
-pub use self::vcs::{existing_vcs_repo, FossilRepo, GitRepo, HgRepo, PijulRepo};
+pub use self::vcs::{existing_vcs_repo, FossilRepo, GitRepo, HgRepo, PijulRepo, RcsRepo};
 pub use self::workspace::{
     add_path_args, path_args, print_available_benches, print_available_binaries,
     print_available_examples, print_available_packages, print_available_tests,

src/cargo/util/vcs.rs

@@ -22,13 +22,16 @@ pub fn existing_vcs_repo(path: &Path, cwd: &Path) -> bool {
         }
     }
 
-    in_git_repo(path, cwd) || HgRepo::discover(path, cwd).is_ok()
+    in_git_repo(path, cwd)
+        || HgRepo::discover(path, cwd).is_ok()
+        || RcsRepo::discover(path, cwd).is_ok()
 }
 
 pub struct HgRepo;
 pub struct GitRepo;
 pub struct PijulRepo;
 pub struct FossilRepo;
+pub struct RcsRepo;
 
 impl GitRepo {
     pub fn init(path: &Path, _: &Path) -> CargoResult<GitRepo> {
@@ -102,3 +105,44 @@ impl FossilRepo {
         Ok(FossilRepo)
     }
 }
+
+impl RcsRepo {
+    pub fn init(path: &Path, _cwd: &Path) -> CargoResult<RcsRepo> {
+        paths::create_dir_all(path.join("RCS"))?;
+        Ok(RcsRepo)
+    }
+
+    pub fn late_init(path: &Path) -> CargoResult<()> {
+        for entry in walkdir::WalkDir::new(path)
+            .into_iter()
+            .filter_entry(|e| e.file_name() != "RCS")
+            .filter_map(|e| e.ok())
+        {
+            let p = entry.path();
+            if p.is_file() {
+                if let Some(parent) = p.parent() {
+                    ProcessBuilder::new("ci")
+                        .cwd(parent)
+                        .arg("-i")
+                        .arg("-l")
+                        .arg("-q")
+                        .arg("-t-''")
+                        .arg(entry.file_name())
+                        .exec()?;
+                }
+            } else if p.is_dir() {
+                paths::create_dir_all(p.join("RCS"))?;
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn discover(path: &Path, _cwd: &Path) -> CargoResult<RcsRepo> {
+        ProcessBuilder::new("rlog")
+            .cwd(&path)
+            .arg("Cargo.toml")
+            .exec_with_output()?;
+        Ok(RcsRepo {})
+    }
+}

src/doc/man/includes/options-new.md

@@ -20,7 +20,7 @@ Set the package name. Defaults to the directory name.
 
 {{#option "`--vcs` _vcs_" }}
 Initialize a new VCS repository for the given version control system (git,
-hg, pijul, or fossil) or do not initialize any version control at all
+hg, pijul, fossil, or rcs) or do not initialize any version control at all
 (none). If not specified, defaults to `git` or the configuration value
 `cargo-new.vcs`, or `none` if already inside a VCS repository.
 {{/option}}

src/doc/src/reference/config.md

@@ -99,7 +99,7 @@ frequency = 'always' # when to display a notification about a future incompat re
 auto-clean-frequency = "1 day"   # How often to perform automatic cache cleaning
 
 [cargo-new]
-vcs = "none"              # VCS to use ('git', 'hg', 'pijul', 'fossil', 'none')
+vcs = "none"              # VCS to use ('git', 'hg', 'pijul', 'fossil', 'rcs', 'none')
 
 [http]
 debug = false               # HTTP debugging
@@ -625,8 +625,8 @@ This option is deprecated and unused.
 * Environment: `CARGO_CARGO_NEW_VCS`
 
 Specifies the source control system to use for initializing a new repository.
-Valid values are `git`, `hg` (for Mercurial), `pijul`, `fossil` or `none` to
-disable this behavior. Defaults to `git`, or `none` if already inside a VCS
+Valid values are `git`, `hg` (for Mercurial), `pijul`, `fossil`, `rcs` or `none`
+to disable this behavior. Defaults to `git`, or `none` if already inside a VCS
 repository. Can be overridden with the `--vcs` CLI option.
 
 ### `[env]`

src/etc/_cargo

@@ -173,7 +173,7 @@ _cargo() {
                     _arguments -s -S $common $registry \
                         '--lib[use library template]' \
                         '--edition=[specify edition to set for the crate generated]:edition:(2015 2018 2021)' \
-                        '--vcs=[initialize a new repo with a given VCS]:vcs:(git hg pijul fossil none)' \
+                        '--vcs=[initialize a new repo with a given VCS]:vcs:(git hg pijul fossil rcs none)' \
                         '--name=[set the resulting package name]:name' \
                         '1:path:_directories'
                         ;;

src/etc/cargo.bashcomp.sh

@@ -28,7 +28,7 @@ _cargo()
 		fi
 	done
 
-	local vcs='git hg none pijul fossil'
+	local vcs='git hg none pijul fossil rcs'
 	local color='auto always never'
 	local msg_format='human json short'
 

tests/testsuite/cargo_init/help/stdout.term.svg

@@ -131,6 +131,21 @@ fn simple_hg() {
     cargo_process("build").cwd(&paths::root().join("foo")).run();
 }
 
+#[cargo_test(requires = "rcs")]
+fn simple_rcs() {
+    cargo_process("new --lib foo --vcs rcs").run();
+
+    assert!(paths::root().is_dir());
+    assert!(paths::root().join("foo/RCS").is_dir());
+    assert!(paths::root().join("foo/RCS/Cargo.toml,v").is_file());
+    assert!(paths::root().join("foo/Cargo.toml").is_file());
+    assert!(paths::root().join("foo/src/RCS").is_dir());
+    assert!(paths::root().join("foo/src/RCS/lib.rs,v").is_file());
+    assert!(paths::root().join("foo/src/lib.rs").is_file());
+
+    cargo_process("build").cwd(&paths::root().join("foo")).run();
+}
+
 #[cargo_test]
 fn no_argument() {
     cargo_process("new")