[PATCH] build/siggen: Add support for stamp 'clean' masks

[Richard Purdie <richard.purdie@linuxfoundation.org>]

Currently when we execute a task, we don't remove other potentially stale
stamps. This can mean if you switch between two different versions of a
recipe without a clean, the build can get very confused.

This patch adds in functionality to allow a wildcard expression of stamp
files to be removed when creating a new stamp file. This patch adds in
the core of the code to enable this but it also requires metadata support
to enable it.

When writing this improvement I went through several different options but
this was the only way I could find to allow things like noexec tasks to
function correctly (where stamps need to be created without the data store).

[YOCTO #2961]

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
---
diff --git a/bitbake/lib/bb/build.py b/bitbake/lib/bb/build.py
index 82d22f7..85af42c 100644
--- a/bitbake/lib/bb/build.py
+++ b/bitbake/lib/bb/build.py
@@ -470,11 +470,40 @@ def stamp_internal(taskname, d, file_name):
 
     return stamp
 
+def stamp_cleanmask_internal(taskname, d, file_name):
+    """
+    Internal stamp helper function to generate stamp cleaning mask
+    Returns the stamp path+filename
+
+    In the bitbake core, d can be a CacheData and file_name will be set.
+    When called in task context, d will be a data store, file_name will not be set
+    """
+    taskflagname = taskname
+    if taskname.endswith("_setscene") and taskname != "do_setscene":
+        taskflagname = taskname.replace("_setscene", "")
+
+    if file_name:
+        stamp = d.stamp_base_clean[file_name].get(taskflagname) or d.stampclean[file_name]
+        extrainfo = d.stamp_extrainfo[file_name].get(taskflagname) or ""
+    else:
+        stamp = d.getVarFlag(taskflagname, 'stamp-base-clean', True) or d.getVar('STAMPCLEAN', True)
+        file_name = d.getVar('BB_FILENAME', True)
+        extrainfo = d.getVarFlag(taskflagname, 'stamp-extra-info', True) or ""
+
+    if not stamp:
+        return
+
+    return bb.parse.siggen.stampcleanmask(stamp, file_name, taskname, extrainfo)
+
 def make_stamp(task, d, file_name = None):
     """
     Creates/updates a stamp for a given task
     (d can be a data dict or dataCache)
     """
+    cleanmask = stamp_cleanmask_internal(task, d, file_name)
+    if cleanmask:
+        bb.utils.remove(cleanmask)
+
     stamp = stamp_internal(task, d, file_name)
     # Remove the file and recreate to force timestamp
     # change on broken NFS filesystems
diff --git a/bitbake/lib/bb/cache.py b/bitbake/lib/bb/cache.py
index dea2a80..619b9ee 100644
--- a/bitbake/lib/bb/cache.py
+++ b/bitbake/lib/bb/cache.py
@@ -43,7 +43,7 @@ except ImportError:
     logger.info("Importing cPickle failed. "
                 "Falling back to a very slow implementation.")
 
-__cache_version__ = "144"
+__cache_version__ = "145"
 
 def getCacheFile(path, filename, data_hash):
     return os.path.join(path, filename + "." + data_hash)
@@ -130,7 +130,9 @@ class CoreRecipeInfo(RecipeInfoCommon):
         self.broken = self.getvar('BROKEN', metadata)
         self.not_world = self.getvar('EXCLUDE_FROM_WORLD', metadata)
         self.stamp = self.getvar('STAMP', metadata)
+        self.stampclean = self.getvar('STAMPCLEAN', metadata)        
         self.stamp_base = self.flaglist('stamp-base', self.tasks, metadata)
+        self.stamp_base_clean = self.flaglist('stamp-base-clean', self.tasks, metadata)
         self.stamp_extrainfo = self.flaglist('stamp-extra-info', self.tasks, metadata)
         self.file_checksums = self.flaglist('file-checksums', self.tasks, metadata, True)
         self.packages_dynamic = self.listvar('PACKAGES_DYNAMIC', metadata)
@@ -157,7 +159,9 @@ class CoreRecipeInfo(RecipeInfoCommon):
         cachedata.pkg_dp = {}
 
         cachedata.stamp = {}
+        cachedata.stampclean = {}
         cachedata.stamp_base = {}
+        cachedata.stamp_base_clean = {}
         cachedata.stamp_extrainfo = {}
         cachedata.file_checksums = {}
         cachedata.fn_provides = {}
@@ -189,7 +193,9 @@ class CoreRecipeInfo(RecipeInfoCommon):
         cachedata.pkg_pepvpr[fn] = (self.pe, self.pv, self.pr)
         cachedata.pkg_dp[fn] = self.defaultpref
         cachedata.stamp[fn] = self.stamp
+        cachedata.stampclean[fn] = self.stampclean
         cachedata.stamp_base[fn] = self.stamp_base
+        cachedata.stamp_base_clean[fn] = self.stamp_base_clean
         cachedata.stamp_extrainfo[fn] = self.stamp_extrainfo
         cachedata.file_checksums[fn] = self.file_checksums
 
diff --git a/bitbake/lib/bb/siggen.py b/bitbake/lib/bb/siggen.py
index 8fe59b9..ff70d4f 100644
--- a/bitbake/lib/bb/siggen.py
+++ b/bitbake/lib/bb/siggen.py
@@ -48,6 +48,9 @@ class SignatureGenerator(object):
     def stampfile(self, stampbase, file_name, taskname, extrainfo):
         return ("%s.%s.%s" % (stampbase, taskname, extrainfo)).rstrip('.')
 
+    def stampcleanmask(self, stampbase, file_name, taskname, extrainfo):
+        return ("%s.%s*.%s" % (stampbase, taskname, extrainfo)).rstrip('.')
+
     def dump_sigtask(self, fn, task, stampbase, runtime):
         return
 
@@ -266,18 +269,24 @@ class SignatureGeneratorBasic(SignatureGenerator):
 class SignatureGeneratorBasicHash(SignatureGeneratorBasic):
     name = "basichash"
 
-    def stampfile(self, stampbase, fn, taskname, extrainfo):
+    def stampfile(self, stampbase, fn, taskname, extrainfo, clean=False):
         if taskname != "do_setscene" and taskname.endswith("_setscene"):
             k = fn + "." + taskname[:-9]
         else:
             k = fn + "." + taskname
-        if k in self.taskhash:
+        if clean:
+            h = "*"
+            taskname = taskname + "*"
+        elif k in self.taskhash:
             h = self.taskhash[k]
         else:
             # If k is not in basehash, then error
             h = self.basehash[k]
         return ("%s.%s.%s.%s" % (stampbase, taskname, h, extrainfo)).rstrip('.')
 
+    def stampcleanmask(self, stampbase, fn, taskname, extrainfo):
+        return self.stampfile(stampbase, fn, taskname, extrainfo, clean=True)
+        
     def invalidate_task(self, task, d, fn):
         bb.note("Tainting hash to force rebuild of task %s, %s" % (fn, task))
         bb.build.write_taint(task, d, fn)