Maintain virtual MuranoPL stack trace

Adds information to executing MuranoPL context that allows
to get currently executed method and instruction with its
location within source YAML file.

All this information can be collected to one stack trace using
stackTrace() function and string-formatted using formatStackTrace()

Change-Id: Ic0aa4e0b2a87d71f76945feb749ecfb0f5a0d299
Implements: blueprint muranopl-stack-traces

murano/dsl/helpers.py

@@ -35,7 +35,7 @@ def serialize(value, memo=None):
             result[d_key] = serialize(d_value, memo)
         return result
     elif isinstance(value, murano.dsl.murano_object.MuranoObject):
-        if not value.object_id in memo:
+        if value.object_id not in memo:
             memo.add(value.object_id)
             return serialize(value.to_dictionary(), memo)
         else:
@@ -47,13 +47,19 @@ def serialize(value, memo=None):
 
 
 def evaluate(value, context, max_depth=sys.maxint):
-    if isinstance(value, (yaql_expression.YaqlExpression,
-                          yaql.expressions.Expression)):
+    if isinstance(value, yaql.expressions.Expression):
+        value = yaql_expression.YaqlExpression(value)
+
+    if isinstance(value, yaql_expression.YaqlExpression):
         func = lambda: evaluate(value.evaluate(context), context, 1)
         if max_depth <= 0:
             return func
         else:
-            return func()
+            try:
+                context.set_data(value, '?currentInstruction')
+                return func()
+            finally:
+                context.set_data(None, '?currentInstruction')
 
     elif isinstance(value, types.DictionaryType):
         result = {}
@@ -178,3 +184,11 @@ def get_caller_context(context):
 
 def get_attribute_store(context):
     return context.get_data('$?attributeStore')
+
+
+def get_current_instruction(context):
+    return context.get_data('$?currentInstruction')
+
+
+def get_current_method(context):
+    return context.get_data('$?currentMethod')

murano/dsl/macros.py

@@ -42,14 +42,21 @@ class CodeBlock(expressions.DslExpression):
 
 
 class MethodBlock(CodeBlock):
+    def __init__(self, body, name=None):
+        super(MethodBlock, self).__init__(body)
+        self._name = name
+
     def execute(self, context, murano_class):
         try:
+            context.set_data(self._name, '?currentMethod')
             super(MethodBlock, self).execute(
                 context, murano_class)
         except exceptions.ReturnException as e:
             return e.value
         else:
             return None
+        finally:
+            context.set_data(None, '?currentMethod')
 
 
 class ReturnMacro(expressions.DslExpression):

murano/dsl/murano_class.py

@@ -101,6 +101,15 @@ class MuranoClass(object):
         if initial and not yielded:
             yield initial
 
+    def find_method(self, name):
+        if name in self._methods:
+            return [(self, name)]
+        if not self._parents:
+            return []
+        return list(set(reduce(
+            lambda x, y: x + y,
+            [p.find_method(name) for p in self._parents])))
+
     def find_single_method(self, name):
         chains = sorted(self._find_method_chains(name), key=lambda t: len(t))
         result = []

murano/dsl/murano_method.py

@@ -51,7 +51,7 @@ class MuranoMethod(object):
                                   MethodUsages.Runtime)
         else:
             payload = payload or {}
-            self._body = self._prepare_body(payload.get('Body') or [])
+            self._body = self._prepare_body(payload.get('Body') or [], name)
             self._usage = payload.get('Usage') or MethodUsages.Runtime
             arguments_scheme = payload.get('Arguments') or []
             if isinstance(arguments_scheme, types.DictionaryType):
@@ -105,8 +105,8 @@ class MuranoMethod(object):
             del result['_context']
         return result
 
-    def _prepare_body(self, body):
-        return macros.MethodBlock(body)
+    def _prepare_body(self, body, name):
+        return macros.MethodBlock(body, name)
 
     def __repr__(self):
         return 'MuranoMethod({0}::{1})'.format(

murano/dsl/virtual_stack.py

@@ -0,0 +1,66 @@
+#    Copyright (c) 2014 Mirantis, Inc.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import os.path
+
+import yaql.context
+
+import murano.dsl.helpers as helpers
+
+
+@yaql.context.ContextAware()
+def stack_trace(context):
+    frames = []
+    while True:
+        context = helpers.get_caller_context(context)
+        if not context:
+            break
+        instruction = helpers.get_current_instruction(context)
+        frames.append({
+            'instruction': None if instruction is None else str(instruction),
+            'location': None if instruction is None
+            else instruction.file_position,
+            'method': helpers.get_current_method(context),
+            'class': helpers.get_type(context)
+        })
+    frames.pop()
+    return frames
+
+
+def format_stack_trace_yaql(trace):
+    return format_stack_trace(trace, '')
+
+
+def format_stack_trace(trace, prefix=''):
+    def format_frame(frame):
+        instruction = frame['instruction']
+        method = frame['method']
+        murano_class = frame['class']
+        location = frame['location']
+
+        if location:
+            return '{5}File "{0}" at {1}:{2} in method {3} of class {6}\n' \
+                   '{5}    {4}'.format(
+                       os.path.abspath(location.file_path),
+                       location.start_line,
+                       location.start_column,
+                       method,
+                       instruction,
+                       prefix,
+                       murano_class.name)
+        else:
+            return '{2}File <unknown> in method {0}\n{2}    {1}'.format(
+                method, instruction, prefix)
+
+    return '\n'.join([format_frame(t)for t in trace()])

murano/dsl/yaql_expression.py

@@ -17,16 +17,38 @@ import types
 
 import yaql
 import yaql.exceptions
+import yaql.expressions
 
 
 class YaqlExpression(object):
     def __init__(self, expression):
-        self._expression = str(expression)
-        self._parsed_expression = yaql.parse(self._expression)
+        if isinstance(expression, types.StringTypes):
+            self._expression = str(expression)
+            self._parsed_expression = yaql.parse(self._expression)
+            self._file_position = None
+        elif isinstance(expression, YaqlExpression):
+            self._expression = expression._expression
+            self._parsed_expression = expression._parsed_expression
+            self._file_position = expression._file_position
+        elif isinstance(expression, yaql.expressions.Expression):
+            self._expression = str(expression)
+            self._parsed_expression = expression
+            self._file_position = None
+        else:
+            raise TypeError('expression is not of supported types')
 
+    @property
     def expression(self):
         return self._expression
 
+    @property
+    def file_position(self):
+        return self._file_position
+
+    @file_position.setter
+    def file_position(self, value):
+        self._file_position = value
+
     def __repr__(self):
         return 'YAQL(%s)' % self._expression
 
@@ -49,3 +71,43 @@ class YaqlExpression(object):
 
     def evaluate(self, context=None):
         return self._parsed_expression.evaluate(context=context)
+
+
+class YaqlExpressionFilePosition(object):
+    def __init__(self, file_path, start_line, start_column, start_index,
+                 end_line, end_column, length):
+        self._file_path = file_path
+        self._start_line = start_line
+        self._start_column = start_column
+        self._start_index = start_index
+        self._end_line = end_line
+        self._end_column = end_column
+        self._length = length
+
+    @property
+    def file_path(self):
+        return self._file_path
+
+    @property
+    def start_line(self):
+        return self._start_line
+
+    @property
+    def start_column(self):
+        return self._start_column
+
+    @property
+    def start_index(self):
+        return self._start_index
+
+    @property
+    def end_line(self):
+        return self._end_line
+
+    @property
+    def end_column(self):
+        return self._end_column
+
+    @property
+    def length(self):
+        return self._length

murano/engine/yaql_yaml_loader.py

@@ -30,7 +30,17 @@ YaqlYamlLoader.yaml_implicit_resolvers = resolvers
 
 def yaql_constructor(loader, node):
     value = loader.construct_scalar(node)
-    return yaql_expression.YaqlExpression(value)
+    result = yaql_expression.YaqlExpression(value)
+    position = yaql_expression.YaqlExpressionFilePosition(
+        node.start_mark.name,
+        node.start_mark.line + 1,
+        node.start_mark.column + 1,
+        node.start_mark.index,
+        node.end_mark.line + 1,
+        node.end_mark.column + 1,
+        node.end_mark.index - node.start_mark.index)
+    result.file_position = position
+    return result
 
 yaml.add_constructor(u'!yaql', yaql_constructor, YaqlYamlLoader)
 yaml.add_implicit_resolver(u'!yaql', yaql_expression.YaqlExpression,

murano/tests/test_engine.py

@@ -453,11 +453,12 @@ class TestHelperFunctions(base.MuranoTestCase):
         # tuple(evaluate(list)) transformation adds + 1
         complex_literal_depth = 3 + 1
 
-        evaluated_value = helpers.evaluate(yaql_value, None, 1)
-        non_evaluated_value = helpers.evaluate(yaql_value, None, 0)
-        evaluated_complex_value = helpers.evaluate(complex_value, None)
+        context = yaql.create_context(False)
+        evaluated_value = helpers.evaluate(yaql_value, context, 1)
+        non_evaluated_value = helpers.evaluate(yaql_value, context, 0)
+        evaluated_complex_value = helpers.evaluate(complex_value, context)
         non_evaluated_complex_value = helpers.evaluate(
-            complex_value, None, complex_literal_depth)
+            complex_value, context, complex_literal_depth)
 
         self.assertEqual('atom', evaluated_value)
         self.assertNotEqual('atom', non_evaluated_value)
@@ -484,7 +485,7 @@ class TestYaqlExpression(base.MuranoTestCase):
     def test_expression(self):
         yaql_expr = yaql_expression.YaqlExpression('string')
 
-        self.assertEqual('string', yaql_expr.expression())
+        self.assertEqual('string', yaql_expr.expression)
 
     def test_evaluate_calls(self):
         string = 'string'