From a6f9617bd891074bba20cc1fc220e60a226e7fb4 Mon Sep 17 00:00:00 2001
From: Peter Wu <lekensteyn@gmail.com>
Date: Fri, 2 Dec 2011 18:43:48 +0000
Subject: WIP for supporting ASM parsing and initialization of variables in
 @DATA

---
 AsmLine.py | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 AsmLine.py

(limited to 'AsmLine.py')

diff --git a/AsmLine.py b/AsmLine.py
new file mode 100644
index 0000000..4561b30
--- /dev/null
+++ b/AsmLine.py
@@ -0,0 +1,114 @@
+#!/usr/bin/env python
+"""Compiles C into assembly for the practicum processor (PP2)
+
+All rights reserved, you may not redistribute or use this program without prior
+permission from Peter Wu or Xander Houtman. Use of this program is entirely
+your own risk. In no circumstances can the authors of this program be held
+responsible for any damage including, but not limited to, financial damage or
+data loss. Modification of this program is not allowed without prior
+permission. The generated output (assembly and messages) are not subject to
+this license.
+"""
+
+__author__ = "Peter Wu"
+__copyright__ = "Copyright 2011, Peter Wu"
+__credits__ = ["Peter Wu"]
+__license__ = "Proprietary"
+__version__ = "1.0"
+__maintainer__ = "Peter Wu"
+__email__ = "uwretep@gmail.com"
+
+import re
+from Asm import Asm
+from Registers import Registers
+from NamedId import NamedId
+
+class AsmLine(object):
+    asm = Asm()
+    registers = Registers()
+    re_whitespace = re.compile("\s+")
+    def __init__(self, line, id_dict=None):
+        # for storing NamedId objects
+        self.id_dict = id_dict
+        self.label = ""
+        self.register = ""
+        self.operand = ""
+        line = line.split(";", 1)[0].strip()
+
+        if ":" in line:
+            self.label, line = line.split(":", 1)
+            self.label = self.label.strip()
+            line = line.strip()
+            if self.asm.is_identifier(self.label):
+                # for easier label name manipulation
+                self.getNamedId(self.label)
+            else:
+                self.label = ""
+                line = label + ":" + line
+
+        parts = self.re_whitespace.split(line, 1)
+        instruction = parts[0]
+        
+        if instruction in Asm.operators_binary:
+            # a label for sure
+            reg, operand = self.re_whitespace.split(parts[1], 1)
+            self.register = reg
+            self.setOperand(operand)
+        elif instruction in Asm.operators_branch:
+            # skip validation of reg for speed
+            self.register = parts[1]
+        elif instruction in Asm.operators_unary:
+            self.setOperand(parts[1])
+        elif instruction in Asm.operators_misc_reg:
+            self.register = parts[1]
+        elif instruction in Asm.operators_misc_noreg:
+            # no args
+            pass
+        else:
+            raise RuntimeError("Unknown instruction '{}'".format(instruction))
+    def setOperand(self, str):
+        """Sets the operand for this object either as a string or an identifier
+        object
+        """
+        if self.id_dict is None:
+            self.operand = str
+        elif self.registers.is_register(str):
+            # register
+            self.operand = [str]
+        else:
+            if str.startswith("["):
+                # split by [ ] and +, grouping multiple occurences
+                self.operand = re.split("([\[\]+]+)", str)
+            else:
+                # value
+                self.operand = [str]
+            for i, part in enumerate(self.operand):
+                # skip empty elements, registers and [ ] +
+                if (part and not self.registers.is_register(part) and
+                    part[0] not in "[]+"):
+                    # turn named items in an object for easier manipulation of
+                    # the names later
+                    # if performance is an issue, you may want to skip the name
+                    # validity check on the cost of NamedIds pollution
+                    if self.asm.is_identifier(part):
+                        self.operand[i] = self.getNamedId(part)
+    def getNamedId(self, name):
+        """Returns an NamedId object for keeping a track of all names at once
+        """
+        # if there is no dictionary to store names, just return the name
+        if self.id_dict is None:
+            return name
+        if name not in self.id_dict:
+            self.id_dict[name] = NamedId(name)
+        return self.id_dict[name]
+    def __str__(self):
+        """Returns a line of assembly"""
+        line = ""
+        if self.label:
+            line += str(self.label) + ": "
+        line += self.instruction
+        if self.register:
+            line += " " + self.register
+        if self.operand:
+            # join all operand parts together
+            line += " " + "".join(str(elm) for elm in self.operand)
-- 
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