// Makes sure that the dependencies for the tasks in the project form a
// valid dependency graph (no cycles).
func checkDependencyGraph(project *model.Project) []ValidationError {
errs := []ValidationError{}
// map of task name and variant -> BuildVariantTask
tasksByNameAndVariant := map[model.TVPair]model.BuildVariantTask{}
// generate task nodes for every task and variant combination
visited := map[model.TVPair]bool{}
allNodes := []model.TVPair{}
for _, bv := range project.BuildVariants {
for _, t := range bv.Tasks {
t.Populate(project.GetSpecForTask(t.Name))
node := model.TVPair{bv.Name, t.Name}
tasksByNameAndVariant[node] = t
visited[node] = false
allNodes = append(allNodes, node)
}
}
// run through the task nodes, checking their dependency graphs for cycles
for _, node := range allNodes {
// the visited nodes
if err := dependencyCycleExists(node, visited, tasksByNameAndVariant); err != nil {
errs = append(errs,
ValidationError{
Message: fmt.Sprintf(
"dependency error for '%v' task: %v", node.TaskName, err),
},
)
}
}
return errs
}
