import: add recipe relative urls

The import SCM base directory is the project root directory. This is
useless for recipes in layers because they don't know their location in
the project. The new "recipeRelative" property can pivot the base
directory to the one where the recipe is located.

pym/bob/scm/imp.py

@@ -116,6 +116,7 @@ class ImportScm(Scm):
     DEFAULTS = {
         schema.Optional('dir') : str,
         schema.Optional('prune') : bool,
+        schema.Optional('recipeRelative') : bool,
     }
 
     __SCHEMA = {
@@ -134,6 +135,11 @@ def __init__(self, spec, overrides=[], pruneDefault=None, fixDigestBug=False, pr
         self.__data = spec.get("__data")
         self.__projectRoot = spec.get("__projectRoot", projectRoot)
         self.__fixDigestBug = fixDigestBug
+        self.__recipeRelative = spec.get("recipeRelative", False)
+
+    def _getSrcDir(self):
+        rootDir = os.path.dirname(self._getRecipe()) if self.__recipeRelative else self.__projectRoot
+        return os.path.join(rootDir, self.__url)
 
     def getProperties(self, isJenkins, pretty=False):
         ret = super().getProperties(isJenkins)
@@ -142,9 +148,10 @@ def getProperties(self, isJenkins, pretty=False):
             'url' : self.__url,
             'dir' : self.__dir,
             'prune' : self.__prune,
+            'recipeRelative' : self.__recipeRelative,
         })
         if isJenkins:
-            ret['__data'] = packTree(self.__url)
+            ret['__data'] = packTree(self._getSrcDir())
         else:
             ret['__projectRoot'] = self.__projectRoot
         return ret
@@ -154,7 +161,7 @@ async def invoke(self, invoker):
         os.makedirs(dest, exist_ok=True)
         if self.__prune: emptyDirectory(dest)
         if self.__data is None:
-            src = os.path.join(self.__projectRoot, self.__url)
+            src = self._getSrcDir()
             if not os.path.isdir(src):
                 invoker.fail("Cannot import '{}': not a directory!".format(src))
             copyTree(src, dest, invoker)

pym/bob/scm/scm.py

@@ -231,6 +231,9 @@ def _diffSpec(self, oldScm):
         ret -= {"if"}
         return ret
 
+    def _getRecipe(self):
+        return self.__recipe
+
     def getSource(self):
         return self.__source