private ProjectDependencyGraph Evaluate(List <Project> rootProjects, BuildEnvironment environment)
{
var projectStack = new Stack <Tmp>(rootProjects.Count);
foreach (var project in rootProjects)
{
projectStack.Push(new Tmp {
Project = project
});
}
var graph = new ProjectDependencyGraph();
while (projectStack.Count > 0)
{
var pair = projectStack.Pop();
var rootProject = pair.Project;
// Evaluating a project means determining the values of properties, the
// presence of nodes, etc...
// Properties of a project (for example $(Configuration)) are written
// back to the environment, but we don't want to one project's enviroment
// to interfere with the next one, thus we create one environment for each
// project.
var projectEnvironment = new BuildEnvironment(environment);
var evaluated = _expressionEngine.Evaluate(rootProject.Merged(_buildScript), projectEnvironment);
graph.Add(evaluated, projectEnvironment);
if (pair.NeededBy != null)
{
graph.AddDependency(pair.NeededBy, evaluated);
}
// Now that we've evaluated the project it's time to find out if it references
// any other projects. This is done afterwards because dependencies might be conditional
// and thus we won't know the dependencies until after evaluating them against the
// current build environment.
// Anyways, we'll simply add any referenced project to the list of projects so that
// we can build all the things!
var references = projectEnvironment.Items.Where(x => x.Type == Items.ProjectReference);
foreach (var reference in references)
{
var path = reference.Include;
if (!Path.IsPathRooted(path))
{
path = Path.Combine(projectEnvironment.Properties[Properties.MSBuildProjectDirectory], path);
}
path = Path.Normalize(path);
if (!graph.Contains(path))
{
var project = _csharpProjectParser.Parse(path);
projectStack.Push(new Tmp
{
Project = project,
NeededBy = evaluated
});
}
}
}
return(graph);
}