Define source maps

kernel/modelverse_jit/source_map.py

@@ -0,0 +1,41 @@
+"""Defines source maps: dictionaries that map lines in generated source to debug information."""
+
+class SourceMap(object):
+    """A source map, which converts generated source lines to debug information."""
+    def __init__(self):
+        self.lines = {}
+
+    def map_line(self, line_number, debug_info):
+        """Assigns the given debug information to the given line."""
+        self.lines[line_number] = debug_info
+
+    def get_debug_info(self, line_number):
+        """Gets the debug information for the given line number, or None if no debug info was
+           found."""
+        return self.lines[line_number]
+
+class SourceMapBuilder(object):
+    """A type of object that makes it easy to build source maps for hierarchical instructions."""
+    def __init__(self, initial_line_number=0):
+        self.source_map = SourceMap()
+        self.debug_info_stack = []
+        self.line_number = initial_line_number - 1
+
+    def push_debug_info(self, debug_info):
+        """Informs the source map that subsequent lines of code will have the given debug
+           information associated with them."""
+        self.debug_info_stack.append(debug_info)
+
+    def pop_debug_info(self):
+        """Informs the source map that the debug information that was pushed last should
+           be discarded in favor of the debug information that was pushed onto the stack
+           just prior to it."""
+        return self.debug_info_stack.pop()
+
+    def append_line(self):
+        """Has the source map builder increment its line number counter, and assigns the debug
+           information that is at the top of the debug information stack to that line."""
+        self.line_number += 1
+        if len(self.debug_info_stack) > 0:
+            self.source_map.map_line(self.line_number, self.debug_info_stack[-1])
+