Merge pull request #931 from jlewicki/soft-dependencies

Issue 929:

src/app/FakeLib/TargetHelper.fs

@@ -335,7 +335,9 @@ let PrintTargets() =
 let private withDependencyType (depType:DependencyType) targets =
  targets |> List.map (fun t -> depType, t)
 
-// Helper function for visiting targets in a dependency tree 
+// Helper function for visiting targets in a dependency tree. Retutrns a set containing the names of the all the 
+// visited targets, and a list containing the targets visited ordered such that dependencies of a target appear earlier
+// in the list than the target.
 let private visitDependencies fVisit targetName = 
  let visit fGetDependencies fVisit targetName = 
  let visited = new HashSet<_>()
@@ -353,17 +355,17 @@ let private visitDependencies fVisit targetName =
  // First pass is to accumulate targets in (hard) dependency graph 
  let visited, _ = visit (fun t -> t.Dependencies |> withDependencyType DependencyType.Hard) (fun _ -> ()) targetName
 
- let getDependencies (t: TargetTemplate<unit>) = 
- if visited.Contains t.Name then
- (t.Dependencies |> withDependencyType DependencyType.Hard) @ 
- (t.SoftDependencies |> List.filter visited.Contains |> withDependencyType DependencyType.Soft)
- else 
- t.Dependencies |> withDependencyType DependencyType.Hard 
-
- // Now make second pass, adding in soft depencencies if approrpriate
- visit getDependencies fVisit targetName
+ let getAllDependencies (t: TargetTemplate<unit>) = 
+ (t.Dependencies |> withDependencyType DependencyType.Hard) @ 
+ // Note that we only include the soft dependency if it is present in the set of targets that were
+ // visited.
+ (t.SoftDependencies |> List.filter visited.Contains |> withDependencyType DependencyType.Soft)
+
+ // Now make second pass, adding in soft depencencies if appropriate
+ visit getAllDependencies fVisit targetName
 
 
+
 /// <summary>Writes a dependency graph.</summary>
 /// <param name="verbose">Whether to print verbose output or not.</param>
 /// <param name="target">The target for which the dependencies should be printed.</param>
@@ -515,21 +517,25 @@ let run targetName =
  let parallelJobs = environVarOrDefault "parallel-jobs" "1" |> int
 
  // Figure out the order in in which targets can be run, and which can be run in parallel.
- let order = determineBuildOrder targetName
-
  if parallelJobs > 1 then
  tracefn "Running parallel build with %d workers" parallelJobs
 
+ // determine a parallel build order
+ let order = determineBuildOrder targetName
+
  // run every level in parallel
  for par in order do
  runTargetsParallel parallelJobs par
 
  else
- // single threaded build. We flatten out the groupings of targets that determineBuildOrder
- // returns, since we don't care about parallel execution.
+ // single threaded build.
  PrintDependencyGraph false targetName
- let flattenedOrder = order |> Seq.collect id |> Seq.toArray
- runTargets flattenedOrder
+
+ // Note: we could use the ordering resulting from flattening the result of determineBuildOrder
+ // for a single threaded build (thereby centralizing the algorithm for build order), but that
+ // ordering is inconsistent with earlier versions of FAKE (and PrintDependencyGraph).
+ let _, ordered = visitDependencies ignore targetName
+ runTargets (ordered |> Seq.map getTarget |> Seq.toArray)
 
  finally
  if errors <> [] then