Handle which branch updates should be taken from in code rather than …

…build script

Cargo.toml

@@ -146,6 +146,7 @@ version = "0.1"
 optional = true
 
 [dev-dependencies]
+semver = "1.0"
 tempfile = "3"
 
 [profile.release]
@@ -170,7 +171,3 @@ self-update = ["semver", "shared_child", "dep:tar", "dep:xz2", "dep:zip", "windo
 compile_commands = []
 # Enable libgit development options.
 gitdev = []
-
-[lints.rust.unexpected_cfgs]
-level = "warn"
-check-cfg = ['cfg(version_check_branch)']

build.rs

@@ -305,33 +305,4 @@ fn main() {
     }
 
     println!("cargo:rerun-if-env-changed=CINNABAR_MAKE_FLAGS");
-
-    #[cfg(any(feature = "version-check", feature = "self-update"))]
-    {
-        // The expected lifecycle is:
-        // - 0.x.0a on branch next
-        // - 0.x.0b on branch master
-        // - 0.x.0b1 on branch release (optionally)
-        // - 0.(x+1).0a on branch next (possibly later)
-        // - 0.x.0rc1 on branch release (optionally)
-        // - 0.x.0 on branch release
-        // - 0.x.1a on branch master
-        // - 0.x.1 on branch release
-        //
-        // Releases will only check tags. Others will check branch heads.
-        let pre = env("CARGO_PKG_VERSION_PRE");
-        let patch = env("CARGO_PKG_VERSION_PATCH");
-        if let "a" | "b" = &*pre {
-            println!("cargo:rustc-cfg=version_check_branch");
-            println!(
-                "cargo:rustc-env=VERSION_CHECK_BRANCH={}",
-                match (&*patch, &*pre) {
-                    ("0", "a") => "next",
-                    ("0", "b") | (_, "a") => "master",
-                    _ => panic!("Unsupported version"),
-                }
-            );
-        }
-        println!("cargo:rerun-if-env-changed=CARGO_PKG_VERSION");
-    }
 }

src/version.rs

@@ -31,3 +31,67 @@ pub const FULL_VERSION: &str = if BUILD_COMMIT.is_empty() {
         if MODIFIED { "-modified" } else { "" }
     )
 };
+
+#[cfg(any(feature = "version-check", feature = "self-update"))]
+#[derive(PartialEq, Eq, Debug)]
+pub enum BuildBranch {
+    Release,
+    Master,
+    Next,
+}
+
+#[cfg(any(feature = "version-check", feature = "self-update"))]
+impl BuildBranch {
+    pub const fn from_version(version: &str) -> BuildBranch {
+        let version = version.as_bytes();
+        // TODO: Use version.last_chunk when MSRV >= 1.80
+        // or version.split_last_chunk when MSRV >= 1.77
+        const fn last_chunk<const N: usize>(b: &[u8]) -> Option<&[u8]> {
+            if b.len() >= N {
+                Some(b.split_at(b.len() - N).1)
+            } else {
+                None
+            }
+        }
+        if matches!(last_chunk::<4>(version), Some(b".0-a")) {
+            BuildBranch::Next
+        } else if matches!(last_chunk::<2>(version), Some(b"-a" | b"-b")) {
+            BuildBranch::Master
+        } else {
+            BuildBranch::Release
+        }
+    }
+
+    pub const fn as_str(&self) -> &'static str {
+        match self {
+            BuildBranch::Release => "release",
+            BuildBranch::Master => "master",
+            BuildBranch::Next => "next",
+        }
+    }
+}
+
+#[cfg(any(feature = "version-check", feature = "self-update"))]
+#[test]
+fn test_build_branch() {
+    use semver::Version;
+
+    // The following tests outline the expected lifecycle.
+    let from_version = |v| {
+        assert!(Version::parse(v).is_ok());
+        BuildBranch::from_version(v)
+    };
+    assert_eq!(from_version("0.2.0-a"), BuildBranch::Next);
+    assert_eq!(from_version("0.2.0-b"), BuildBranch::Master);
+    assert_eq!(from_version("0.2.0-b1"), BuildBranch::Release); // optionally
+    assert_eq!(from_version("0.2.0-beta1"), BuildBranch::Release); // alternative form
+    assert_eq!(from_version("0.2.0-beta1"), BuildBranch::Release); // alternative form
+    assert_eq!(from_version("0.3.0-a"), BuildBranch::Next); // possibly later
+    assert_eq!(from_version("0.2.0-rc1"), BuildBranch::Release); // optionally
+    assert_eq!(from_version("0.2.0"), BuildBranch::Release); // optionally
+    assert_eq!(from_version("0.2.1-a"), BuildBranch::Master);
+    assert_eq!(from_version("0.2.1"), BuildBranch::Release);
+}
+
+#[cfg(any(feature = "version-check", feature = "self-update"))]
+pub const BUILD_BRANCH: BuildBranch = BuildBranch::from_version(SHORT_VERSION);

src/version_check.rs

@@ -21,15 +21,12 @@ use crate::git::CommitId;
 #[cfg(feature = "version-check")]
 use crate::util::DurationExt;
 use crate::util::{FromBytes, OsStrExt, ReadExt, SliceExt};
-use crate::version::{BUILD_COMMIT, SHORT_VERSION};
+use crate::version::BuildBranch::*;
+use crate::version::{BUILD_BRANCH, BUILD_COMMIT, SHORT_VERSION};
 #[cfg(feature = "version-check")]
 use crate::{check_enabled, get_config, Checks};
 
 const ALL_TAG_REFS: &str = "refs/tags/*";
-#[cfg(version_check_branch)]
-const VERSION_CHECK_REF: &str = env!("VERSION_CHECK_BRANCH");
-#[cfg(not(version_check_branch))]
-const VERSION_CHECK_REF: &str = ALL_TAG_REFS;
 #[cfg(feature = "version-check")]
 const VERSION_CHECK_CONFIG: &str = "cinnabar.version-check";
 
@@ -49,10 +46,10 @@ impl<'a> From<&'a str> for VersionRequest<'a> {
 
 impl<'a> Default for VersionRequest<'a> {
     fn default() -> Self {
-        if VERSION_CHECK_REF == ALL_TAG_REFS {
+        if BUILD_BRANCH == Release {
             VersionRequest::Tagged
         } else {
-            VersionRequest::Branch(VERSION_CHECK_REF)
+            VersionRequest::Branch(BUILD_BRANCH.as_str())
         }
     }
 }
@@ -159,7 +156,7 @@ impl VersionChecker {
 impl Drop for VersionChecker {
     fn drop(&mut self) {
         match self.take_result() {
-            Some(VersionInfo::Tagged(version, _)) if VERSION_CHECK_REF == ALL_TAG_REFS => {
+            Some(VersionInfo::Tagged(version, _)) if BUILD_BRANCH == Release => {
                 if self.show_current {
                     warn!(
                         target: "root",
@@ -180,11 +177,11 @@ impl Drop for VersionChecker {
                     );
                 }
             }
-            Some(VersionInfo::Commit(_)) if VERSION_CHECK_REF != ALL_TAG_REFS => {
+            Some(VersionInfo::Commit(_)) if BUILD_BRANCH != Release => {
                 warn!(
                     target: "root",
                     "The {} branch of git-cinnabar was updated. {}",
-                    VERSION_CHECK_REF,
+                    BUILD_BRANCH.as_str(),
                     if cfg!(feature = "self-update") {
                         "You may run `git cinnabar self-update` to update."
                     } else {