From 86c119a507570144b02645dd262e7d0b8864aa2d Mon Sep 17 00:00:00 2001
From: Daniel Dunbar <daniel@zuster.org>
Date: Thu, 3 Nov 2011 17:56:16 +0000
Subject: [PATCH] llvm-build: Fill in some details w.r.t. component's parents.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143624 91177308-0d34-0410-b5e6-96231b3b80d8
---
 utils/llvm-build/llvmbuild/componentinfo.py |  9 +++++++++
 utils/llvm-build/llvmbuild/main.py          | 18 ++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/utils/llvm-build/llvmbuild/componentinfo.py b/utils/llvm-build/llvmbuild/componentinfo.py
index 22ce0b4fde7..30ec23b8330 100644
--- a/utils/llvm-build/llvmbuild/componentinfo.py
+++ b/utils/llvm-build/llvmbuild/componentinfo.py
@@ -37,6 +37,15 @@ class ComponentInfo(object):
         # under.
         self.parent = parent
 
+        # The parent instance, once loaded.
+        self.parent_instance = None
+        self.children = []
+
+    def set_parent_instance(self, parent):
+        assert parent.name == self.parent, "Unexpected parent!"
+        self.parent_instance = parent
+        self.parent_instance.children.append(self)
+
     def get_component_references(self):
         """get_component_references() -> iter
 
diff --git a/utils/llvm-build/llvmbuild/main.py b/utils/llvm-build/llvmbuild/main.py
index a734ac16414..e04f0acb967 100644
--- a/utils/llvm-build/llvmbuild/main.py
+++ b/utils/llvm-build/llvmbuild/main.py
@@ -54,6 +54,12 @@ class LLVMProjectInfo(object):
                         ci.name, ci.subpath, existing.subpath))
             self.component_info_map[ci.name] = ci
 
+        # Add the root component, which does not go in any list.
+        if '$ROOT' in self.component_info_map:
+            fatal("project is not allowed to define $ROOT component")
+        self.component_info_map['$ROOT'] = componentinfo.GroupComponentInfo(
+            '/', '$ROOT', None)
+
         # Topologically order the component information according to their
         # component references.
         def visit_component_info(ci, current_stack, current_set):
@@ -73,6 +79,13 @@ class LLVMProjectInfo(object):
             # Otherwise, mark the component info as visited and traverse.
             components_to_visit.remove(ci)
 
+            # Validate the parent reference, which we treat specially.
+            parent = self.component_info_map.get(ci.parent)
+            if parent is None:
+                fatal("component %r has invalid reference %r (via %r)" % (
+                        ci.name, ci.parent, 'parent'))
+            ci.set_parent_instance(parent)
+
             for relation,referent_name in ci.get_component_references():
                 # Validate that the reference is ok.
                 referent = self.component_info_map.get(referent_name)
@@ -90,6 +103,11 @@ class LLVMProjectInfo(object):
             # Finally, add the component info to the ordered list.
             self.ordered_component_infos.append(ci)
 
+        # FIXME: We aren't actually correctly checking for cycles along the
+        # parent edges. Haven't decided how I want to handle this -- I thought
+        # about only checking cycles by relation type. If we do that, it falls
+        # out easily. If we don't, we should special case the check.
+
         self.ordered_component_infos = []
         components_to_visit = set(component_infos)
         while components_to_visit:
-- 
2.34.1