[Add] First commit

scripts/imgtool/macro_parser.py

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+#! /usr/bin/env python3
+#
+# -----------------------------------------------------------------------------
+# Copyright (c) 2019, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+# -----------------------------------------------------------------------------
+
+
+import re
+import os
+
+expression_re = re.compile(r"[(]?(([(]?(((0x)[0-9a-fA-F]+)|([0-9]+))[)]?)\s*([\+\-]\s*([(]?(((0x)[0-9a-fA-F]+)|([0-9]+))[)]?)\s*)*)[)]?")
+
+# Simple parser that takes a string and evaluates an expression from it.
+# The expression might contain additions and subtractions amongst numbers that
+# are written in decimal or hexadecimal form.
+# The parses can process expressions in which the parentheses does not change
+# the sign of the following number or numbers in an expression.
+# Thus the parser can process the following expression: (x + y)
+# However it will not calculate the correct sum for the expression below:
+# (x - (y + z))
+def parse_and_sum(text):
+    m = expression_re.match(text)
+    if m is None:
+        msg = "The script was probably invoked manually"
+        msg += " with having certain macros nested in flash_layouts.h.\n"
+        msg += "Please revisit the flash_layout.h file and hardcode values"
+        msg += " for the (NON-)SECURE_IMAGE_OFFSET and"
+        msg += " (NON-)SECURE_IMAGE_MAX_SIZE macros"
+        raise Exception(msg)
+
+    nums = re.findall(r'(0x[A-Fa-f0-9]+)|[\d]+', m.group(0))
+    for i in range(len(nums)):
+        nums[i] = int(nums[i], 0)
+    ops = re.findall(r'\+|\-', m.group(0))
+    sum = nums[0]
+    for i in range(len(ops)):
+        if ops[i] == '+':
+            sum += nums[i+1]
+        else:
+            sum -= nums[i+1]
+    return sum
+
+
+# Opens a file that contains the macro of interest, then finds the macro with
+# a regular expression, parses the expression that is defined for the given
+# macro. Lastly it evaluates the expression with the parse_and_sum function
+def evaluate_macro(file, regexp, matchGroupKey, matchGroupData):
+    regexp_compiled = re.compile(regexp)
+
+    if os.path.isabs(file):
+        configFile = file
+    else:
+        scriptsDir = os.path.dirname(os.path.abspath(__file__))
+        configFile = os.path.join(scriptsDir, file)
+
+    macroValue = {}
+    with open(configFile, 'r') as macros_preprocessed_file:
+        for line in macros_preprocessed_file:
+            m = regexp_compiled.match(line)
+            if m is not None:
+                macroValue[m.group(matchGroupKey)] = \
+                parse_and_sum(m.group(matchGroupData))
+
+    if (matchGroupKey == 0 and not macroValue):
+        macroValue["None"] = None
+
+    return list(macroValue.values())[0] if (matchGroupKey == 0) else macroValue