data_smart: Fix expand_cache and _remove operator interaction issues

The contents of the expand_cache is meant to match the return value of
getVarFlag() but the implementation was mostly in expandWithRefs(). If
an incorrect key was passed to expandWithRefs(), or a variable was only
partially expanded with no remove processing, the cache could become
corrupted.

Move the code to getVarFlag making the data lifecycle very clear, meaning
other calls to expandWithRefs() cannot corrupt the cache.

The expand_cache reset code needs to be moved ahead of any remote data
connectors too, since the expand_cache is now on the local side of the
connection.

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

1 files changed, 23 insertions, 27 deletions

diff --git a/lib/bb/data_smart.py b/lib/bb/data_smart.py
index 7b2c0a894..ecc71bd64 100644
--- a/lib/bb/data_smart.py
+++ b/lib/bb/data_smart.py
@@ -105,11 +105,7 @@ class VariableParse:
             if self.varname and key:
                 if self.varname == key:
                     raise Exception("variable %s references itself!" % self.varname)
-            if key in self.d.expand_cache:
-                varparse = self.d.expand_cache[key]
-                var = varparse.value
-            else:
-                var = self.d.getVarFlag(key, "_content")
+            var = self.d.getVarFlag(key, "_content")
             self.references.add(key)
             if var is not None:
                 return var
@@ -412,9 +408,6 @@ class DataSmart(MutableMapping):
         if not isinstance(s, str): # sanity check
             return VariableParse(varname, self, s)
 
-        if varname and varname in self.expand_cache:
-            return self.expand_cache[varname]
-
         varparse = VariableParse(varname, self)
 
         while s.find('${') != -1:
@@ -438,9 +431,6 @@ class DataSmart(MutableMapping):
 
         varparse.value = s
 
-        if varname:
-            self.expand_cache[varname] = varparse
-
         return varparse
 
     def expand(self, s, varname = None):
@@ -509,6 +499,7 @@ class DataSmart(MutableMapping):
 
     def setVar(self, var, value, **loginfo):
         #print("var=" + str(var) + "  val=" + str(value))
+        self.expand_cache = {}
         parsing=False
         if 'parsing' in loginfo:
             parsing=True
@@ -521,7 +512,7 @@ class DataSmart(MutableMapping):
 
         if 'op' not in loginfo:
             loginfo['op'] = "set"
-        self.expand_cache = {}
+
         match  = __setvar_regexp__.match(var)
         if match and match.group("keyword") in __setvar_keyword__:
             base = match.group('base')
@@ -672,6 +663,7 @@ class DataSmart(MutableMapping):
         self.setVar(var + "_prepend", value, ignore=True, parsing=True)
 
     def delVar(self, var, **loginfo):
+        self.expand_cache = {}
         if '_remote_data' in self.dict:
             connector = self.dict["_remote_data"]["_content"]
             res = connector.delVar(var)
@@ -681,7 +673,6 @@ class DataSmart(MutableMapping):
         loginfo['detail'] = ""
         loginfo['op'] = 'del'
         self.varhistory.record(**loginfo)
-        self.expand_cache = {}
         self.dict[var] = {}
         if var in self.overridedata:
             del self.overridedata[var]
@@ -704,13 +695,13 @@ class DataSmart(MutableMapping):
                          override = None
 
     def setVarFlag(self, var, flag, value, **loginfo):
+        self.expand_cache = {}
         if '_remote_data' in self.dict:
             connector = self.dict["_remote_data"]["_content"]
             res = connector.setVarFlag(var, flag, value)
             if not res:
                 return
 
-        self.expand_cache = {}
         if 'op' not in loginfo:
             loginfo['op'] = "set"
         loginfo['flag'] = flag
@@ -732,6 +723,17 @@ class DataSmart(MutableMapping):
             self.dict["__exportlist"]["_content"].add(var)
 
     def getVarFlag(self, var, flag, expand=True, noweakdefault=False, parsing=False):
+        if flag == "_content":
+            cachename = var
+        else:
+            if not flag:
+                bb.warn("Calling getVarFlag with flag unset is invalid")
+                return None
+            cachename = var + "[" + flag + "]"
+
+        if expand and cachename in self.expand_cache:
+            return self.expand_cache[cachename].value
+
         local_var, overridedata = self._findVar(var)
         value = None
         if flag == "_content" and overridedata is not None and not parsing:
@@ -796,14 +798,9 @@ class DataSmart(MutableMapping):
                 if match:
                     value = r + value
 
-        if expand and value:
-            # Only getvar (flag == _content) hits the expand cache
-            cachename = None
-            if flag == "_content":
-                cachename = var
-            else:
-                cachename = var + "[" + flag + "]"
-            value = self.expand(value, cachename)
+        if expand:
+            self.expand_cache[cachename] = self.expandWithRefs(value, cachename)
+            value = self.expand_cache[cachename].value
 
         if value and flag == "_content" and local_var is not None and "_remove" in local_var and not parsing:
             removes = []
@@ -821,20 +818,19 @@ class DataSmart(MutableMapping):
                 filtered = filter(lambda v: v not in removes,
                                   __whitespace_split__.split(value))
                 value = "".join(filtered)
-                if expand and var in self.expand_cache:
-                    # We need to ensure the expand cache has the correct value
-                    # flag == "_content" here
-                    self.expand_cache[var].value = value
+                if expand and cachename in self.expand_cache:
+                    self.expand_cache[cachename].value = value
+
         return value
 
     def delVarFlag(self, var, flag, **loginfo):
+        self.expand_cache = {}
         if '_remote_data' in self.dict:
             connector = self.dict["_remote_data"]["_content"]
             res = connector.delVarFlag(var, flag)
             if not res:
                 return
 
-        self.expand_cache = {}
         local_var, _ = self._findVar(var)
         if not local_var:
             return