Add --must-have-and-exclude-feature option.

Author: xStrom

CHANGELOG.md

@@ -12,6 +12,8 @@ Note: In this file, do not use the hard wrap in the middle of a sentence for com
 
 ## [Unreleased]
 
+- Add `--must-have-and-exclude-feature` option. ([#262](https://github.com/taiki-e/cargo-hack/pull/262), thanks @xStrom)
+
 ## [0.6.35] - 2025-02-11
 
 - Performance improvements.

README.md

@@ -162,6 +162,15 @@ OPTIONS:
             This flag can only be used together with either --each-feature flag or
             --feature-powerset flag.
 
+        --must-have-and-exclude-feature <FEATURE>
+            Require the specified feature to be present but excluded.
+
+            Exclude the specified feature and all other features which depend on it.
+
+            Exclude packages which don't have the specified feature.
+
+            This is useful for doing no_std testing with --must-have-and-exclude-feature std.
+
         --no-dev-deps
             Perform without dev-dependencies.
 

src/cli.rs

@@ -37,6 +37,8 @@ pub(crate) struct Args {
     pub(crate) each_feature: bool,
     /// --feature-powerset
     pub(crate) feature_powerset: bool,
+    /// --must-have-and-exclude-feature <FEATURE>
+    pub(crate) must_have_and_exclude_feature: Option<String>,
     /// --no-dev-deps
     pub(crate) no_dev_deps: bool,
     /// --remove-dev-deps
@@ -152,6 +154,7 @@ impl Args {
         let mut remove_dev_deps = false;
         let mut each_feature = false;
         let mut feature_powerset = false;
+        let mut must_have_and_exclude_feature = None;
         let mut no_private = false;
         let mut ignore_private = false;
         let mut ignore_unknown_features = false;
@@ -303,6 +306,9 @@ impl Args {
                 Long("remove-dev-deps") => parse_flag!(remove_dev_deps),
                 Long("each-feature") => parse_flag!(each_feature),
                 Long("feature-powerset") => parse_flag!(feature_powerset),
+                Long("must-have-and-exclude-feature") => {
+                    parse_opt!(must_have_and_exclude_feature, false);
+                }
                 Long("at-least-one-of") => at_least_one_of.push(parser.value()?.parse()?),
                 Long("no-private") => parse_flag!(no_private),
                 Long("ignore-private") => parse_flag!(ignore_private),
@@ -492,6 +498,8 @@ impl Args {
                 conflicts("--all-features", "--each-feature")?;
             } else if feature_powerset {
                 conflicts("--all-features", "--feature-powerset")?;
+            } else if must_have_and_exclude_feature.is_some() {
+                conflicts("--all-features", "--must-have-and-exclude-feature")?;
             }
         }
         if no_default_features {
@@ -520,6 +528,21 @@ impl Args {
             }
         }
 
+        if let Some(f) = must_have_and_exclude_feature.as_ref() {
+            if features.contains(f) {
+                bail!("feature `{f}` specified by both --must-have-and-exclude-feature and --features");
+            }
+            if optional_deps.as_ref().is_some_and(|d| d.contains(f)) {
+                bail!("feature `{f}` specified by both --must-have-and-exclude-feature and --optional-deps");
+            }
+            if group_features.iter().any(|v| v.matches(f)) {
+                bail!("feature `{f}` specified by both --must-have-and-exclude-feature and --group-features");
+            }
+            if include_features.contains(f) {
+                bail!("feature `{f}` specified by both --must-have-and-exclude-feature and --include-features");
+            }
+        }
+
         if subcommand.is_none() {
             if cargo_args.iter().any(|a| a == "--list") {
                 cmd!(cargo, "--list").run()?;
@@ -591,7 +614,8 @@ impl Args {
         exclude_no_default_features |= !include_features.is_empty();
         exclude_all_features |= !include_features.is_empty()
             || !exclude_features.is_empty()
-            || !mutually_exclusive_features.is_empty();
+            || !mutually_exclusive_features.is_empty()
+            || must_have_and_exclude_feature.is_some();
         exclude_features.extend_from_slice(&features);
 
         term::verbose::set(verbose != 0);
@@ -613,6 +637,7 @@ impl Args {
             workspace,
             each_feature,
             feature_powerset,
+            must_have_and_exclude_feature,
             no_dev_deps,
             remove_dev_deps,
             no_private,
@@ -758,6 +783,11 @@ const HELP: &[HelpText<'_>] = &[
              --feature-powerset flag.",
         ],
     ),
+    ("", "--must-have-and-exclude-feature", "<FEATURE>", "Require the specified feature to be present but excluded", &[
+        "Exclude the specified feature and all other features which depend on it.",
+        "Exclude packages which don't have the specified feature.",
+        "This is useful for doing no_std testing with --must-have-and-exclude-feature std.",
+    ]),
     ("", "--no-dev-deps", "", "Perform without dev-dependencies", &[
         "Note that this flag removes dev-dependencies from real `Cargo.toml` while cargo-hack is \
          running and restores it when finished.",

src/features.rs

@@ -84,6 +84,10 @@ impl Features {
     pub(crate) fn contains(&self, name: &str) -> bool {
         self.features.iter().any(|f| f == name)
     }
+
+    pub(crate) fn get(&self, name: &str) -> Option<&Feature> {
+        self.features.iter().find(|f| *f == name)
+    }
 }
 
 /// The representation of Cargo feature.

src/main.rs

@@ -200,9 +200,13 @@ fn determine_kind<'a>(
 
     let package = cx.packages(id);
     let pkg_features = cx.pkg_features(id);
+    let recursively_exclude_feature =
+        cx.must_have_and_exclude_feature.as_ref().and_then(|s| pkg_features.get(s));
     let filter = |&f: &&Feature| {
         !cx.exclude_features.iter().any(|s| f == s)
             && !cx.group_features.iter().any(|g| g.matches(f.name()))
+            && !recursively_exclude_feature
+                .is_some_and(|rf| rf.matches_recursive(f.name(), &package.features))
     };
     let features = if cx.include_features.is_empty() {
         // TODO
@@ -340,10 +344,14 @@ fn determine_package_list(cx: &Context) -> Result<Vec<PackageRuns<'_>>> {
             );
         }
     }
+    let has_required_features = |id: &&PackageId| {
+        cx.must_have_and_exclude_feature.as_ref().is_none_or(|s| cx.pkg_features(id).contains(s))
+    };
     Ok(if cx.workspace {
         let ids: Vec<_> = cx
             .workspace_members()
             .filter(|id| !cx.exclude.contains(&cx.packages(id).name))
+            .filter(has_required_features)
             .collect();
         let multiple_packages = ids.len() > 1;
         ids.iter().filter_map(|id| determine_kind(cx, id, multiple_packages)).collect()
@@ -360,13 +368,15 @@ fn determine_package_list(cx: &Context) -> Result<Vec<PackageRuns<'_>>> {
             .workspace_members()
             .filter(|id| cx.package.contains(&cx.packages(id).name))
             .filter(|id| !cx.exclude.contains(&cx.packages(id).name))
+            .filter(has_required_features)
             .collect();
         let multiple_packages = ids.len() > 1;
         ids.iter().filter_map(|id| determine_kind(cx, id, multiple_packages)).collect()
     } else if cx.current_package().is_none() {
         let ids: Vec<_> = cx
             .workspace_members()
             .filter(|id| !cx.exclude.contains(&cx.packages(id).name))
+            .filter(has_required_features)
             .collect();
         let multiple_packages = ids.len() > 1;
         ids.iter().filter_map(|id| determine_kind(cx, id, multiple_packages)).collect()
@@ -376,6 +386,7 @@ fn determine_package_list(cx: &Context) -> Result<Vec<PackageRuns<'_>>> {
         cx.workspace_members()
             .find(|id| cx.packages(id).name == *current_package)
             .filter(|id| !cx.exclude.contains(&cx.packages(id).name))
+            .filter(has_required_features)
             .and_then(|id| determine_kind(cx, id, multiple_packages).map(|p| vec![p]))
             .unwrap_or_default()
     })

src/process.rs

@@ -98,19 +98,28 @@ impl<'a> ProcessBuilder<'a> {
     }
 
     pub(crate) fn append_features_from_args(&mut self, cx: &Context, id: &PackageId) {
-        if cx.ignore_unknown_features {
-            self.append_features(cx.features.iter().filter(|&f| {
-                if cx.pkg_features(id).contains(f) {
-                    true
-                } else {
-                    // ignored
-                    info!("skipped applying unknown `{f}` feature to {}", cx.packages(id).name);
-                    false
-                }
-            }));
-        } else if !cx.features.is_empty() {
-            self.append_features(&cx.features);
-        }
+        let package = cx.packages(id);
+        let pkg_features = cx.pkg_features(id);
+        let recursively_exclude_feature =
+            cx.must_have_and_exclude_feature.as_ref().and_then(|s| pkg_features.get(s));
+
+        self.append_features(cx.features.iter().filter(|&f| {
+            if recursively_exclude_feature
+                .is_some_and(|rf| rf.matches_recursive(f, &package.features))
+            {
+                info!(
+                    "skipped applying `{f}` feature to {} because it would enable excluded feature `{}`",
+                    package.name,
+                    recursively_exclude_feature.unwrap().name()
+                );
+                false
+            } else if cx.ignore_unknown_features && !pkg_features.contains(f) {
+                info!("skipped applying unknown `{f}` feature to {}", package.name);
+                false
+            } else {
+                true
+            }
+        }));
     }
 
     /// Gets the comma-separated features list

tests/fixtures/must_have_and_exclude_feature/Cargo.toml

@@ -0,0 +1,7 @@
+[workspace]
+resolver = "2"
+members = [
+    "member1",
+    "member2",
+	"member3",
+]

tests/fixtures/must_have_and_exclude_feature/member1/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "member1"
+version = "0.0.0"
+
+[features]
+default = ["c"]
+a = []
+b = []
+c = ["b"]
+
+[dependencies]
+
+[dev-dependencies]

tests/fixtures/must_have_and_exclude_feature/member1/src/main.rs

@@ -0,0 +1 @@
+fn main() {}

tests/fixtures/must_have_and_exclude_feature/member2/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "member2"
+version = "0.0.0"
+
+[features]
+default = ["a"]
+a = []
+b = []
+c = ["b"]
+
+[dependencies]
+
+[dev-dependencies]