bitbake/gcc: Enable a shared common source tree

This patch is a quick proof of concept to show how source code could
be shared between recipes which use ${B} to have a separate build
directory compared to source directory ${S}.

Issues:

a) gcc uses sed and creates config files against ${S} which means
the directory should not be shared. Need to change the way that works.

b) Could be extended to cover eglibc except there is a patch applied
against nativesdk versions which again makes the source incompatible.

c) Need to clean up the layout in work-shared and make a directory level deeper
to ensure patch separation.

d) clean task does not remove stamps

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

3 files changed, 14 insertions, 2 deletions

diff --git a/bitbake/lib/bb/build.py b/bitbake/lib/bb/build.py
index 83a378febb..19a9ba12f1 100644
--- a/bitbake/lib/bb/build.py
+++ b/bitbake/lib/bb/build.py
@@ -382,10 +382,10 @@ def stamp_internal(taskname, d, file_name):
         taskflagname = taskname.replace("_setscene", "")
 
     if file_name:
-        stamp = d.stamp[file_name]
+        stamp = d.stamp_base[file_name].get(taskflagname) or d.stamp[file_name]
         extrainfo = d.stamp_extrainfo[file_name].get(taskflagname) or ""
     else:
-        stamp = d.getVar('STAMP', True)
+        stamp = d.getVarFlag(taskflagname, 'stamp-base', True) or d.getVar('STAMP', True)
         file_name = d.getVar('BB_FILENAME', True)
         extrainfo = d.getVarFlag(taskflagname, 'stamp-extra-info', True) or ""
 
diff --git a/bitbake/lib/bb/cache.py b/bitbake/lib/bb/cache.py
index c56b4b4248..4e76857e6f 100644
--- a/bitbake/lib/bb/cache.py
+++ b/bitbake/lib/bb/cache.py
@@ -55,6 +55,7 @@ recipe_fields = (
     'provides',
     'task_deps',
     'stamp',
+    'stamp_base',
     'stamp_extrainfo',
     'broken',
     'not_world',
@@ -160,6 +161,7 @@ class RecipeInfo(namedtuple('RecipeInfo', recipe_fields)):
             broken           = cls.getvar('BROKEN', metadata),
             not_world        = cls.getvar('EXCLUDE_FROM_WORLD', metadata),
             stamp            = cls.getvar('STAMP', metadata),
+            stamp_base       = cls.flaglist('stamp-base', tasks, metadata),
             stamp_extrainfo  = cls.flaglist('stamp-extra-info', tasks, metadata),
             packages_dynamic = cls.listvar('PACKAGES_DYNAMIC', metadata),
             depends          = cls.depvar('DEPENDS', metadata),
@@ -579,6 +581,7 @@ class CacheData(object):
         self.task_queues = {}
         self.task_deps = {}
         self.stamp = {}
+        self.stamp_base = {}
         self.stamp_extrainfo = {}
         self.preferred = {}
         self.tasks = {}
@@ -604,6 +607,7 @@ class CacheData(object):
         self.pkg_pepvpr[fn] = (info.pe, info.pv, info.pr)
         self.pkg_dp[fn] = info.defaultpref
         self.stamp[fn] = info.stamp
+        self.stamp_base[fn] = info.stamp_base
         self.stamp_extrainfo[fn] = info.stamp_extrainfo
 
         provides = [info.pn]
diff --git a/bitbake/lib/bb/runqueue.py b/bitbake/lib/bb/runqueue.py
index 3db083b261..cb9e462869 100644
--- a/bitbake/lib/bb/runqueue.py
+++ b/bitbake/lib/bb/runqueue.py
@@ -105,6 +105,11 @@ class RunQueueScheduler(object):
             if self.rq.runq_running[taskid] == 1:
                 continue
             if self.rq.runq_buildable[taskid] == 1:
+                fn = self.rqdata.taskData.fn_index[self.rqdata.runq_fnid[taskid]]
+                taskname = self.rqdata.runq_task[taskid]
+                stamp = bb.build.stampfile(taskname, self.rqdata.dataCache, fn)
+                if stamp in self.rq.build_stamps.values():
+                    continue
                 return taskid
 
     def next(self):
@@ -1010,6 +1015,7 @@ class RunQueueExecute:
         self.runq_complete = []
         self.build_pids = {}
         self.build_pipes = {}
+        self.build_stamps = {}
         self.failed_fnids = []
 
     def runqueue_process_waitpid(self):
@@ -1024,6 +1030,7 @@ class RunQueueExecute:
         del self.build_pids[result[0]]
         self.build_pipes[result[0]].close()
         del self.build_pipes[result[0]]
+        del self.build_stamps[result[0]]
         if result[1] != 0:
             self.task_fail(task, result[1]>>8)
         else:
@@ -1312,6 +1319,7 @@ class RunQueueExecuteTasks(RunQueueExecute):
 
             self.build_pids[pid] = task
             self.build_pipes[pid] = runQueuePipe(pipein, pipeout, self.cfgData)
+            self.build_stamps[pid] = bb.build.stampfile(taskname, self.rqdata.dataCache, fn)
             self.runq_running[task] = 1
             self.stats.taskActive()
             if self.stats.active < self.number_tasks: