Change have_dev_units from a bool to enum HasDevUnits for clarity.

Author: ehuss

src/cargo/core/compiler/standard_lib.rs

@@ -3,7 +3,7 @@
 use crate::core::compiler::{BuildContext, CompileKind, CompileMode, RustcTargetData, Unit};
 use crate::core::profiles::UnitFor;
 use crate::core::resolver::features::ResolvedFeatures;
-use crate::core::resolver::ResolveOpts;
+use crate::core::resolver::{HasDevUnits, ResolveOpts};
 use crate::core::{Dependency, PackageId, PackageSet, Resolve, SourceId, Workspace};
 use crate::ops::{self, Packages};
 use crate::util::errors::CargoResult;
@@ -102,8 +102,14 @@ pub fn resolve_std<'cfg>(
         /*dev_deps*/ false, &features, /*all_features*/ false,
         /*uses_default_features*/ true,
     );
-    let resolve =
-        ops::resolve_ws_with_opts(&std_ws, target_data, requested_target, &opts, &specs, false)?;
+    let resolve = ops::resolve_ws_with_opts(
+        &std_ws,
+        target_data,
+        requested_target,
+        &opts,
+        &specs,
+        HasDevUnits::No,
+    )?;
     Ok((
         resolve.pkg_set,
         resolve.targeted_resolve,

src/cargo/core/resolver/features.rs

@@ -56,8 +56,20 @@ struct FeatureOpts {
     compare: bool,
 }
 
+/// Flag to indicate if Cargo is building *any* dev units (tests, examples, etc.).
+///
+/// This disables decoupling of dev dependencies. It may be possible to relax
+/// this in the future, but it will require significant changes to how unit
+/// dependencies are computed, and can result in longer build times with
+/// `cargo test` because the lib may need to be built 3 times instead of
+/// twice.
+pub enum HasDevUnits {
+    Yes,
+    No,
+}
+
 impl FeatureOpts {
-    fn new(config: &Config, has_dev_units: bool) -> CargoResult<FeatureOpts> {
+    fn new(config: &Config, has_dev_units: HasDevUnits) -> CargoResult<FeatureOpts> {
         let mut opts = FeatureOpts::default();
         let unstable_flags = config.cli_unstable();
         opts.package_features = unstable_flags.package_features;
@@ -93,13 +105,7 @@ impl FeatureOpts {
                 enable(&env_opts)?;
             }
         }
-        if has_dev_units {
-            // Decoupling of dev deps is not allowed if any test/bench/example
-            // is being built. It may be possible to relax this in the future,
-            // but it will require significant changes to how unit
-            // dependencies are computed, and can result in longer build times
-            // with `cargo test` because the lib may need to be built 3 times
-            // instead of twice.
+        if let HasDevUnits::Yes = has_dev_units {
             opts.decouple_dev_deps = false;
         }
         Ok(opts)
@@ -211,7 +217,7 @@ impl<'a, 'cfg> FeatureResolver<'a, 'cfg> {
         requested_features: &RequestedFeatures,
         specs: &[PackageIdSpec],
         requested_target: CompileKind,
-        has_dev_units: bool,
+        has_dev_units: HasDevUnits,
     ) -> CargoResult<ResolvedFeatures> {
         use crate::util::profile;
         let _p = profile::start("resolve features");

src/cargo/core/resolver/mod.rs

@@ -69,6 +69,7 @@ use self::types::{FeaturesSet, RcVecIter, RemainingDeps, ResolverProgress};
 pub use self::encode::Metadata;
 pub use self::encode::{EncodableDependency, EncodablePackageId, EncodableResolve};
 pub use self::errors::{ActivateError, ActivateResult, ResolveError};
+pub use self::features::HasDevUnits;
 pub use self::resolve::{Resolve, ResolveVersion};
 pub use self::types::ResolveOpts;
 

src/cargo/ops/cargo_clean.rs

@@ -7,7 +7,7 @@ use crate::core::compiler::unit_dependencies;
 use crate::core::compiler::{BuildConfig, BuildContext, CompileKind, CompileMode, Context};
 use crate::core::compiler::{RustcTargetData, UnitInterner};
 use crate::core::profiles::{Profiles, UnitFor};
-use crate::core::resolver::features::{FeatureResolver, RequestedFeatures};
+use crate::core::resolver::features::{FeatureResolver, HasDevUnits, RequestedFeatures};
 use crate::core::{PackageIdSpec, Workspace};
 use crate::ops;
 use crate::util::errors::{CargoResult, CargoResultExt};
@@ -86,7 +86,7 @@ pub fn clean(ws: &Workspace<'_>, opts: &CleanOptions<'_>) -> CargoResult<()> {
         &requested_features,
         &specs,
         bcx.build_config.requested_kind,
-        true,
+        HasDevUnits::Yes,
     )?;
     let mut units = Vec::new();
 

src/cargo/ops/cargo_compile.rs

@@ -35,7 +35,7 @@ use crate::core::compiler::{CompileKind, CompileMode, RustcTargetData, Unit};
 use crate::core::compiler::{DefaultExecutor, Executor, UnitInterner};
 use crate::core::profiles::{Profiles, UnitFor};
 use crate::core::resolver::features;
-use crate::core::resolver::{Resolve, ResolveOpts};
+use crate::core::resolver::{HasDevUnits, Resolve, ResolveOpts};
 use crate::core::{LibKind, Package, PackageSet, Target};
 use crate::core::{PackageId, PackageIdSpec, TargetKind, Workspace};
 use crate::ops;
@@ -312,7 +312,10 @@ pub fn compile_ws<'a>(
     let specs = spec.to_package_id_specs(ws)?;
     let dev_deps = ws.require_optional_deps() || filter.need_dev_deps(build_config.mode);
     let opts = ResolveOpts::new(dev_deps, features, all_features, !no_default_features);
-    let has_dev_units = filter.need_dev_deps(build_config.mode);
+    let has_dev_units = match filter.need_dev_deps(build_config.mode) {
+        true => HasDevUnits::Yes,
+        false => HasDevUnits::No,
+    };
     let resolve = ops::resolve_ws_with_opts(
         ws,
         &target_data,

src/cargo/ops/cargo_doc.rs

@@ -1,5 +1,5 @@
 use crate::core::compiler::RustcTargetData;
-use crate::core::resolver::ResolveOpts;
+use crate::core::resolver::{HasDevUnits, ResolveOpts};
 use crate::core::{Shell, Workspace};
 use crate::ops;
 use crate::util::CargoResult;
@@ -27,8 +27,14 @@ pub fn doc(ws: &Workspace<'_>, options: &DocOptions<'_>) -> CargoResult<()> {
     );
     let requested_kind = options.compile_opts.build_config.requested_kind;
     let target_data = RustcTargetData::new(ws, requested_kind)?;
-    let ws_resolve =
-        ops::resolve_ws_with_opts(ws, &target_data, requested_kind, &opts, &specs, false)?;
+    let ws_resolve = ops::resolve_ws_with_opts(
+        ws,
+        &target_data,
+        requested_kind,
+        &opts,
+        &specs,
+        HasDevUnits::No,
+    )?;
 
     let ids = specs
         .iter()

src/cargo/ops/cargo_install.rs

@@ -8,7 +8,7 @@ use tempfile::Builder as TempFileBuilder;
 
 use crate::core::compiler::Freshness;
 use crate::core::compiler::{CompileKind, DefaultExecutor, Executor, RustcTargetData};
-use crate::core::resolver::ResolveOpts;
+use crate::core::resolver::{HasDevUnits, ResolveOpts};
 use crate::core::{Edition, Package, PackageId, PackageIdSpec, Source, SourceId, Workspace};
 use crate::ops;
 use crate::ops::common_for_install_and_uninstall::*;
@@ -506,7 +506,7 @@ fn check_yanked_install(ws: &Workspace<'_>) -> CargoResult<()> {
         CompileKind::Host,
         &ResolveOpts::everything(),
         &specs,
-        false,
+        HasDevUnits::No,
     )?;
     let mut sources = ws_resolve.pkg_set.sources_mut();
 

src/cargo/ops/cargo_output_metadata.rs

@@ -1,7 +1,6 @@
 use crate::core::compiler::{CompileKind, CompileTarget, RustcTargetData};
-use crate::core::resolver::{Resolve, ResolveOpts};
-
 use crate::core::dependency::DepKind;
+use crate::core::resolver::{HasDevUnits, Resolve, ResolveOpts};
 use crate::core::{Dependency, InternedString, Package, PackageId, Workspace};
 use crate::ops::{self, Packages};
 use crate::util::CargoResult;
@@ -125,7 +124,7 @@ fn build_resolve_graph(
         requested_kind,
         &resolve_opts,
         &specs,
-        true,
+        HasDevUnits::Yes,
     )?;
     // Download all Packages. This is needed to serialize the information
     // for every package. In theory this could honor target filtering,

src/cargo/ops/resolve.rs

@@ -13,7 +13,7 @@
 use crate::core::compiler::{CompileKind, RustcTargetData};
 use crate::core::registry::PackageRegistry;
 use crate::core::resolver::features::{FeatureResolver, ResolvedFeatures};
-use crate::core::resolver::{self, Resolve, ResolveOpts};
+use crate::core::resolver::{self, HasDevUnits, Resolve, ResolveOpts};
 use crate::core::summary::Summary;
 use crate::core::Feature;
 use crate::core::{PackageId, PackageIdSpec, PackageSet, Source, SourceId, Workspace};
@@ -78,7 +78,7 @@ pub fn resolve_ws_with_opts<'a>(
     requested_target: CompileKind,
     opts: &ResolveOpts,
     specs: &[PackageIdSpec],
-    has_dev_units: bool,
+    has_dev_units: HasDevUnits,
 ) -> CargoResult<WorkspaceResolve<'a>> {
     let mut registry = PackageRegistry::new(ws.config())?;
     let mut add_patches = true;