From 5d484f08cf8850bad0842789dab3fccd523e566c Mon Sep 17 00:00:00 2001
From: Anton Lydike <me@antonlydike.de>
Date: Sat, 24 Apr 2021 18:24:11 +0200
Subject: [PATCH] Minor fixes like imports and edge-case handling

---
 riscemu/Executable.py       | 3 ++-
 riscemu/ExecutableParser.py | 1 +
 riscemu/MMU.py              | 5 +++++
 riscemu/__init__.py         | 2 +-
 riscemu/helpers.py          | 1 -
 5 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/riscemu/Executable.py b/riscemu/Executable.py
index 176625a..ed48eb5 100644
--- a/riscemu/Executable.py
+++ b/riscemu/Executable.py
@@ -12,6 +12,7 @@ from dataclasses import dataclass, field
 from typing import Dict, List, Tuple, Union, Optional
 from .Exceptions import *
 from .helpers import *
+from math import log
 
 import typing
 
@@ -215,7 +216,7 @@ class LoadedMemorySection:
             print(FMT_MEM + "{}, viewing {} bytes:".format(
                 self, end - start
             ) + FMT_NONE)
-            for i in range(start, end, bytes_per_row):
+            for i in range(0, end - start, bytes_per_row):
                 data = self.content[start + i: min(start + i + bytes_per_row, end)]
                 if start + i <= highlight <= start + i + bytes_per_row:
                     # do hightlight here!
diff --git a/riscemu/ExecutableParser.py b/riscemu/ExecutableParser.py
index 550fce0..c3a9fd7 100644
--- a/riscemu/ExecutableParser.py
+++ b/riscemu/ExecutableParser.py
@@ -75,6 +75,7 @@ class ExecutableParser:
         :param token: the symbol token
         """
         ASSERT_NOT_IN(token.name, self.symbols)
+        ASSERT_NOT_NULL(self.active_section)
         sec_pos = self._curr_sec().size
         self.symbols[token.name] = (self.active_section, sec_pos)
 
diff --git a/riscemu/MMU.py b/riscemu/MMU.py
index 0f2e40e..e4e4bfc 100644
--- a/riscemu/MMU.py
+++ b/riscemu/MMU.py
@@ -141,6 +141,10 @@ class MMU:
         :return: The Instruction
         """
         sec = self.get_sec_containing(addr)
+        if sec is None:
+            print(FMT_MEM + "[MMU] Trying to read instruction form invalid region! "
+                            "Have you forgotten an exit syscall or ret statement?" + FMT_NONE)
+            raise RuntimeError("No next instruction available!")
         return sec.read_instruction(addr - sec.base)
 
     def read(self, addr: int, size: int) -> bytearray:
@@ -175,6 +179,7 @@ class MMU:
         """
         sec = self.get_sec_containing(addr)
         if sec is None:
+            print(FMT_MEM + "[MMU] No section containing addr 0x{:08X}".format(addr) + FMT_NONE)
             return
         sec.dump(addr, *args, **kwargs)
 
diff --git a/riscemu/__init__.py b/riscemu/__init__.py
index 7bf2073..f030752 100644
--- a/riscemu/__init__.py
+++ b/riscemu/__init__.py
@@ -13,7 +13,7 @@ from .Exceptions import RiscemuBaseException, LaunchDebuggerException, InvalidSy
 
 from .Tokenizer import RiscVInput, RiscVTokenizer
 
-from .Executable import Executable, LoadedExecutable
+from .Executable import Executable, LoadedExecutable, LoadedMemorySection
 
 from .ExecutableParser import ExecutableParser
 
diff --git a/riscemu/helpers.py b/riscemu/helpers.py
index 5faadad..97458cc 100644
--- a/riscemu/helpers.py
+++ b/riscemu/helpers.py
@@ -96,5 +96,4 @@ def format_bytes(byte_arr: bytearray, fmt: str, group: int = 1, highlight: int =
         return highlight_in_list([('{:0' + spc + 'd}').format(int_from_bytes(ch, unsigned=True)) for ch in chunks],
                                  highlight)
     if fmt == 'ascii':
-        print("printing ascii", "".join(chr(b) for b in byte_arr))
         return "".join(repr(chr(b))[1:-1] for b in byte_arr)