context: include dependencies from inherited tasks

In most cases, inheriting tasks want to use the same dependencies as
their ancestors. For special cases like gcc's header stubs, a noinherit
flag can be set on dependencies.

4 files changed, 66 insertions, 12 deletions

diff --git a/examples/gcc.yml b/examples/gcc.yml
index ac67a31..4bc19f4 100644
--- a/examples/gcc.yml
+++ b/examples/gcc.yml
@@ -30,6 +30,7 @@ tasks:
           target: 'target'
     depends:
       - task: 'header-stubs'
+        noinherit: true
     run: |
       mkdir gcc-build
       cd gcc-build
@@ -85,6 +86,7 @@ tasks:
           target: 'target'
     depends:
       - task: 'header-stubs'
+        noinherit: true
     run: |
       cd gcc-build
       make -j8 all-host
diff --git a/examples/libgcc-initial.yml b/examples/libgcc-initial.yml
index 89a6734..046ff4f 100644
--- a/examples/libgcc-initial.yml
+++ b/examples/libgcc-initial.yml
@@ -14,6 +14,7 @@ tasks:
     depends:
       - recipe: 'gcc'
         task: 'header-stubs'
+        noinherit: true
     run: |
       cd gcc-build
       make configure-target-libgcc
@@ -43,6 +44,7 @@ tasks:
     depends:
       - recipe: 'gcc'
         task: 'header-stubs'
+        noinherit: true
     run: |
       cd gcc-build
       make -j8 all-target-libgcc
diff --git a/src/context.rs b/src/context.rs
index 139b5d7..2fc4905 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -18,14 +18,14 @@ use crate::{
 	util::error,
 };
 
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy)]
 pub enum ErrorKind<'ctx> {
 	TaskNotFound,
 	InvalidArgument(&'ctx str),
 	InvalidArgRef(&'ctx str),
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy)]
 pub struct Error<'ctx> {
 	pub task: &'ctx TaskID,
 	pub kind: ErrorKind<'ctx>,
@@ -231,26 +231,74 @@ impl Context {
 		Some(self.inherit_ref(inherit, &task_ref.args)).transpose()
 	}
 
+	fn inherit_iter<'ctx>(
+		&'ctx self,
+		task_ref: &TaskRef<'ctx>,
+	) -> impl Iterator<Item = Result<TaskRef>> {
+		struct Iter<'ctx>(&'ctx Context, Option<Result<'ctx, TaskRef<'ctx>>>);
+
+		impl<'ctx> Iterator for Iter<'ctx> {
+			type Item = Result<'ctx, TaskRef<'ctx>>;
+
+			fn next(&mut self) -> Option<Self::Item> {
+				let task_ref = match self.1.take()? {
+					Ok(task_ref) => task_ref,
+					Err(err) => return Some(Err(err)),
+				};
+				self.1 = self.0.get_inherit_depend(&task_ref).transpose();
+				Some(Ok(task_ref))
+			}
+		}
+
+		Iter(self, Some(Ok(task_ref.clone())))
+	}
+
 	pub fn get_build_depends<'ctx>(
 		&'ctx self,
 		task_ref: &TaskRef<'ctx>,
 	) -> Result<HashSet<OutputRef>> {
-		let task = self.get(task_ref.id)?;
-		task.build_depends
-			.iter()
-			.map(|dep| self.output_ref(dep, &task_ref.args, true))
-			.collect()
+		let mut ret = HashSet::new();
+		let mut allow_noinherit = true;
+
+		for current in self.inherit_iter(task_ref) {
+			let task_ref = current?;
+			let task = self.get(task_ref.id)?;
+			let entries = task
+				.build_depends
+				.iter()
+				.filter(|dep| allow_noinherit || !dep.noinherit)
+				.map(|dep| self.output_ref(dep, &task_ref.args, true))
+				.collect::<Result<Vec<_>>>()?;
+			ret.extend(entries);
+
+			allow_noinherit = false;
+		}
+
+		Ok(ret)
 	}
 
 	pub fn get_host_depends<'ctx>(
 		&'ctx self,
 		task_ref: &TaskRef<'ctx>,
 	) -> Result<HashSet<OutputRef>> {
-		let task = self.get(task_ref.id)?;
-		task.depends
-			.iter()
-			.map(|dep| self.output_ref(dep, &task_ref.args, false))
-			.collect()
+		let mut ret = HashSet::new();
+		let mut allow_noinherit = true;
+
+		for current in self.inherit_iter(task_ref) {
+			let task_ref = current?;
+			let task = self.get(task_ref.id)?;
+			let entries = task
+				.depends
+				.iter()
+				.filter(|dep| allow_noinherit || !dep.noinherit)
+				.map(|dep| self.output_ref(dep, &task_ref.args, false))
+				.collect::<Result<Vec<_>>>()?;
+			ret.extend(entries);
+
+			allow_noinherit = false;
+		}
+
+		Ok(ret)
 	}
 
 	pub fn in_rootfs<'ctx>(&'ctx self, output: &OutputRef<'ctx>) -> bool {
diff --git a/src/task.rs b/src/task.rs
index f921774..ca7f494 100644
--- a/src/task.rs
+++ b/src/task.rs
@@ -36,6 +36,8 @@ pub struct InheritDep {
 pub struct OutputDep {
 	#[serde(flatten)]
 	pub dep: TaskDep,
+	#[serde(default)]
+	pub noinherit: bool,
 	#[serde(default = "default_output_name")]
 	pub output: String,
 }