Assembly files often use tabs, only disallow trailing tabs.

.gitignore

@@ -58,3 +58,4 @@ fujinet_releases/*
 *~
 *.orig
 *.rej
+*.lst

coding-standard.py

@@ -46,6 +46,11 @@ class FormatError(Enum):
   IllegalTabs = auto()
   CodingStandardViolation = auto()
 
+class TabsOk(Enum):
+  Nope = auto()      # Calling it "None" seems confusing
+  Leading = auto()
+  AllTabs = auto()
+
 ErrorStrings = {
   FormatError.TrailingWhitespace: "Trailing whitespace",
   FormatError.IllegalTabs: "Tab characters",
@@ -140,9 +145,11 @@ def __init__(self, path, contents=None):
     if contents is None:
       raise ValueError("Contents not provided")
 
-    self.allowLeadingTab = False
+    self.allowTabs = TabsOk.Nope
     if self.isMakefile:
-      self.allowLeadingTab = True
+      self.allowTabs = TabsOk.Leading
+    elif self.isAssembly:
+      self.allowTabs = TabsOk.AllTabs
 
     return
 
@@ -153,7 +160,7 @@ def splitLeadingTab(self, line):
     """
     prefix = ""
     suffix = line
-    if self.allowLeadingTab:
+    if self.allowTabs == TabsOk.Leading:
       if line and line[0] == '\t':
         prefix = line[:1]
         suffix = line[1:]
@@ -177,7 +184,7 @@ def fixupWhitespace(self):
     lines = []
     for line in self.contents:
       line = line.rstrip()
-      if "\t" in line:
+      if self.allowTabs != TabsOk.AllTabs and "\t" in line:
         prefix, suffix = self.splitLeadingTab(line)
         while "\t" in suffix:
           column = suffix.index("\t")
@@ -243,9 +250,6 @@ def checkFormatting(self, repo):
       else:
         formatted = self.fixupWhitespace()
 
-    elif self.isMakefile:
-      formatted = self.fixupWhitespace()
-
     else:
       formatted = self.fixupWhitespace()
 
@@ -268,7 +272,7 @@ def classifyErrors(self):
       trailingStart = len(line.rstrip())
       line = line[:trailingStart]
       prefix, suffix = self.splitLeadingTab(line)
-      if "\t" in suffix:
+      if self.allowTabs != TabsOk.AllTabs and "\t" in suffix:
         errors.add(FormatError.IllegalTabs)
         break
 
@@ -317,6 +321,12 @@ def isMakefile(self):
         return True
     return False
 
+  @property
+  def isAssembly(self):
+    if self.path.suffix in [".asm", ".s"]:
+      return True
+    return False
+
   @property
   def isPython(self):
     if self.path.suffix == ".py" or self.contents[0].startswith("#!/usr/bin/env python"):