Make header include guards great again

runtime/PRESUBMIT.py

Index: runtime/PRESUBMIT.py
diff --git a/runtime/PRESUBMIT.py b/runtime/PRESUBMIT.py
index ca55214e37d40bafd6e68ebc7d7a566a9916499e..f67f0d6952da966ef05c64d5d9831d6a8ee6c37a 100644
--- a/runtime/PRESUBMIT.py
+++ b/runtime/PRESUBMIT.py
@@ -6,37 +6,23 @@ import os
 import cpplint
 import re
 
-
-class PathHackException(Exception):
-  def __init__(self, error_msg):
-    self.error_msg = error_msg
-
-  def __str__(self):
-    return repr(self.error_msg)
-
-def AddSvnPathIfNeeded(runtime_path):
-  # Add the .svn into the runtime directory if needed for git or svn 1.7.
-  fake_svn_path = os.path.join(runtime_path, '.svn')
-  if os.path.exists(fake_svn_path):
-    return None
-  open(fake_svn_path, 'w').close()
-  return lambda: os.remove(fake_svn_path)
-
-
-def TrySvnPathHack(parent_path):
-  orig_path = os.path.join(parent_path, '.svn')
-  renamed_path = os.path.join(parent_path, '.svn_orig')
-  if os.path.exists(renamed_path):
-    error_msg = '".svn_orig" exists in presubmit parent directory('
-    error_msg += parent_path
-    error_msg += '). Consider renaming it manually to ".svn".'
-    raise PathHackException(error_msg)
-  if os.path.exists(orig_path):
-    # Make the parent SVN directory non-discoverable by cpplint to get
-    # the correct header guard checks. This is needed if using all Dart
-    # checkout.
-    os.rename(orig_path, renamed_path)
-    return lambda: os.rename(renamed_path, orig_path)
+# memcpy does not handle overlapping memory regions. Even though this
+# is well documented it seems to be used in error quite often. To avoid
+# problems we disallow the direct use of memcpy.  The exceptions are in
+# third-party code and in platform/globals.h which uses it to implement
+# bit_cast and bit_copy.
+def CheckMemcpy(filename):
+  if filename.endswith(os.path.join('platform', 'globals.h')) or \
+     filename.find('third_party') != -1:
+    return 0
+  fh = open(filename, 'r')
+  content = fh.read()
+  match = re.search('\\bmemcpy\\b', content)
+  if match:
+    line_number = content[0:match.start()].count('\n') + 1
+    print "%s:%d: use of memcpy is forbidden" % (filename, line_number)
+    return 1
+  return 0
 
 
 def RunLint(input_api, output_api):
@@ -44,39 +30,13 @@ def RunLint(input_api, output_api):
   cpplint._cpplint_state.ResetErrorCounts()
   memcpy_match_count = 0
   # Find all .cc and .h files in the change list.
-  for svn_file in input_api.AffectedTextFiles():
-    filename = svn_file.AbsoluteLocalPath()
+  for git_file in input_api.AffectedTextFiles():
+    filename = git_file.AbsoluteLocalPath()
     if filename.endswith('.cc') or filename.endswith('.h'):
-      cleanup_parent = None

[rmacnak, 2016/10/25 16:42:33]

Removing this changes the linter's notion of the project root. E.g.:

/usr/local/google/home/rmacnak/ssd/dart2/sdk/runtime/vm/heap.h:5:  #ifndef
header guard has wrong style, please use: RUNTIME_VM_HEAP_H_ 
[build/header_guard] [5]
/usr/local/google/home/rmacnak/ssd/dart2/sdk/runtime/vm/heap.h:400:  #endif line
should be "#endif  // RUNTIME_VM_HEAP_H_"  [build/header_guard] [5]

The comment from TrySvnPathHack suggests we did this so that, back when there
was a way to checkout just the VM without the SDK, the VM-only checkout and SDK
checkout produced the same linter results. Given there's only one kind of
checkout now, perhaps we should just adopt the longer header guards.

-      cleanup_runtime = None
-      try:
-        runtime_path = input_api.PresubmitLocalPath()
-        parent_path = os.path.dirname(runtime_path)
-        if filename.endswith('.h'):
-          cleanup_runtime = AddSvnPathIfNeeded(runtime_path)
-          cleanup_parent = TrySvnPathHack(parent_path)
-      except PathHackException, exception:
-        return [output_api.PresubmitError(str(exception))]
       # Run cpplint on the file.
       cpplint.ProcessFile(filename, 1)
-      if cleanup_parent is not None:
-        cleanup_parent()
-      if cleanup_runtime is not None:
-        cleanup_runtime()
-      # memcpy does not handle overlapping memory regions. Even though this
-      # is well documented it seems to be used in error quite often. To avoid
-      # problems we disallow the direct use of memcpy.  The exceptions are in
-      # third-party code and in platform/globals.h which uses it to implement
-      # bit_cast and bit_copy.
-      if not filename.endswith(os.path.join('platform', 'globals.h')) and \
-         filename.find('third_party') == -1:
-        fh = open(filename, 'r')
-        content = fh.read()
-        match = re.search('\\bmemcpy\\b', content)
-        if match:
-          line_number = content[0:match.start()].count('\n') + 1
-          print "%s:%d: use of memcpy is forbidden" % (filename, line_number)
-          memcpy_match_count += 1
+      # Check for memcpy use.
+      memcpy_match_count += CheckMemcpy(filename)
 
   # Report a presubmit error if any of the files had an error.
   if cpplint._cpplint_state.error_count > 0 or memcpy_match_count > 0: