Remove datetime.utcnow() support from OverrideValidation.py (#586)

## Description

* Remove support for datetime.utcnow() function as it is slated for
deprecation.
https://docs.python.org/3/library/datetime.html#datetime.datetime.utcnow
* Removed unused import of subprocess.
* Pull in change to FlattenPdbs.py to unblock build validation.

- [ ] Impacts functionality?
- **Functionality** - Does the change ultimately impact how firmware
functions?
- Examples: Add a new library, publish a new PPI, update an algorithm,
...
- [ ] Impacts security?
- **Security** - Does the change have a direct security impact on an
application,
    flow, or firmware?
  - Examples: Crypto algorithm change, buffer overflow fix, parameter
    validation improvement, ...
- [x] Breaking change?
- **Breaking change** - Will anyone consuming this change experience a
break
    in build or boot behavior?
Yes, anyone using Python 3.9 and older will no longer be able to use the
FlattenPdbs plug-in. Tangentially, this will cause builds to break that
include this plug-in if using Python 3.9 or older.
The fix is to upgrade python to 3.10 or newer.
- [ ] Includes tests?
  - **Tests** - Does the change include any explicit test code?
  - Examples: Unit tests, integration tests, robot tests, ...
- [ ] Includes documentation?
- **Documentation** - Does the change contain explicit documentation
additions
    outside direct code modifications (and comments)?
- Examples: Update readme file, add feature readme file, link to
documentation
    on an a separate Web page, ...

## How This Was Tested

* Verified override tag parsing and creation produced the correct UTC
time.

## Integration Instructions

N/A

BaseTools/Plugin/FlattenPdbs/FlattenPdbs.py

@@ -1,7 +1,7 @@
 ## @file FlattenPdbs.py
 # Plugin to support copying all PDBs to 1 directory.
 # This makes symbol publishing easier and with the usage of
-# ALT PDB PATH can shrink the size of each module. 
+# ALT PDB PATH can shrink the size of each module.
 #
 ##
 # Copyright (c) Microsoft Corporation. All rights reserved.
@@ -27,7 +27,7 @@
 # OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 # ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ##
-### 
+###
 from edk2toolext.environment.plugintypes.uefi_build_plugin import IUefiBuildPlugin
 import logging
 from pathlib import Path
@@ -61,5 +61,5 @@ def do_post_build(self, thebuilder):
             # Hard link it, which is slightly faster, but mainly allows us to tell
             # if the file has changed (st_ino is different)
             pdb_out.unlink(missing_ok=True)
-            file.link_to(pdb_out) # Replace with pdb_out.hardlink_to(file) when support for python 3.9 is dropped
+            pdb_out.hardlink_to(file)
         return 0

BaseTools/Plugin/OverrideValidation/OverrideValidation.py

@@ -8,15 +8,14 @@
 ##
 
 
-import logging
-import os
-import io
-import sys
-from datetime import datetime
-import subprocess
 import argparse
 import hashlib
+import io
+import logging
+import os
 import re
+import sys
+from datetime import datetime, timezone
 from io import StringIO
 
 #
@@ -25,11 +24,12 @@
 #
 #
 try:
-    from edk2toolext.environment.plugintypes.uefi_build_plugin import IUefiBuildPlugin
-    from edk2toollib.uefi.edk2.parsers.inf_parser import InfParser
-    from edk2toollib.utility_functions import RunCmd
+    from edk2toolext.environment.plugintypes.uefi_build_plugin import \
+        IUefiBuildPlugin
     from edk2toollib.uefi.edk2.parsers.dsc_parser import *
+    from edk2toollib.uefi.edk2.parsers.inf_parser import InfParser
     from edk2toollib.uefi.edk2.path_utilities import Edk2Path
+    from edk2toollib.utility_functions import RunCmd
 
     #Tuple for (version, entrycount)
     FORMAT_VERSION_1 = (1, 4)   #Version 1: #OVERRIDE : VERSION | PATH_TO_MODULE | HASH | YYYY-MM-DDThh-mm-ss
@@ -304,6 +304,7 @@ def override_process_line_with_version1(self, thebuilder, filelist, OverrideEntr
             # Step 4: Parse the time of hash generation
             try:
                 EntryTimestamp = datetime.strptime(OverrideEntry[3].strip(), "%Y-%m-%dT%H-%M-%S")
+                EntryTimestamp = EntryTimestamp.replace(tzinfo=timezone.utc)
             except ValueError:
                 logging.error("Inf Override Parse Error, override parameter has invalid timestamp %s" %(OverrideEntry[3].strip()))
                 result = self.OverrideResult.OR_INVALID_FORMAT
@@ -318,7 +319,7 @@ def override_process_line_with_version1(self, thebuilder, filelist, OverrideEntr
             # Step 6: House keeping
             # Process the path to workspace/package path based add it to the parent node
             overridden_rel_path = self.PathTool.GetEdk2RelativePathFromAbsolutePath(fullpath)
-            date_delta = datetime.utcnow() - EntryTimestamp
+            date_delta = datetime.now(timezone.utc) - EntryTimestamp
 
             m_node.entry_hash = EntryHash
             m_node.path = overridden_rel_path
@@ -401,7 +402,7 @@ def override_log_print(self, thebuilder, modulelist, status):
             with open(logfile, 'w') as log:
                 log.write("Platform:     %s\n" %(thebuilder.env.GetValue("PRODUCT_NAME")))
                 log.write("Version:      %s\n" %(thebuilder.env.GetValue("BLD_*_BUILDID_STRING")))
-                log.write("Date:         %s\n" %(datetime.utcnow().strftime("%Y-%m-%dT%H-%M-%S")))
+                log.write("Date:         %s\n" %(datetime.now(timezone.utc).strftime("%Y-%m-%dT%H-%M-%S")))
                 log.write("Commit:       %s\n" %(thebuilder.env.GetValue("BLD_*_BUILDSHA")))
                 log.write("State:        %d/%d\n" %(status[0], status[1]))
 
@@ -670,10 +671,10 @@ def path_parse():
                         VERSION_INDEX = Paths.Version - 1
 
                         if VERSION_INDEX == 0:
-                            line = '#%s : %08d | %s | %s | %s\n' % (match.group(1), FORMAT_VERSION_1[0], rel_path, mod_hash, datetime.utcnow().strftime("%Y-%m-%dT%H-%M-%S"))
+                            line = '#%s : %08d | %s | %s | %s\n' % (match.group(1), FORMAT_VERSION_1[0], rel_path, mod_hash, datetime.now(timezone.utc).strftime("%Y-%m-%dT%H-%M-%S"))
                         elif VERSION_INDEX == 1:
                             git_hash = ModuleGitHash(abs_path)
-                            line = '#%s : %08d | %s | %s | %s | %s\n' % (match.group(1), FORMAT_VERSION_2[0], rel_path, mod_hash, datetime.utcnow().strftime("%Y-%m-%dT%H-%M-%S"), git_hash)
+                            line = '#%s : %08d | %s | %s | %s | %s\n' % (match.group(1), FORMAT_VERSION_2[0], rel_path, mod_hash, datetime.now(timezone.utc).strftime("%Y-%m-%dT%H-%M-%S"), git_hash)
                         print("Updating:\n" + line)
                 else:
                     print(f"Warning: Could not resolve relative path {rel_path}. Override line not updated.\n")
@@ -705,9 +706,9 @@ def path_parse():
 
         if VERSION_INDEX == 0:
             print("Copy and paste the following line(s) to your overrider inf file(s):\n")
-            print('#%s : %08d | %s | %s | %s' % ("Override" if not Paths.Track else "Track", FORMAT_VERSION_1[0], rel_path, mod_hash, datetime.utcnow().strftime("%Y-%m-%dT%H-%M-%S")))
+            print('#%s : %08d | %s | %s | %s' % ("Override" if not Paths.Track else "Track", FORMAT_VERSION_1[0], rel_path, mod_hash, datetime.now(timezone.utc).strftime("%Y-%m-%dT%H-%M-%S")))
 
         elif VERSION_INDEX == 1:
             git_hash = ModuleGitHash(Paths.TargetPath)
             print("Copy and paste the following line(s) to your overrider inf file(s):\n")
-            print('#%s : %08d | %s | %s | %s | %s' % ("Override" if not Paths.Track else "Track", FORMAT_VERSION_2[0], rel_path, mod_hash, datetime.utcnow().strftime("%Y-%m-%dT%H-%M-%S"), git_hash))
+            print('#%s : %08d | %s | %s | %s | %s' % ("Override" if not Paths.Track else "Track", FORMAT_VERSION_2[0], rel_path, mod_hash, datetime.now(timezone.utc).strftime("%Y-%m-%dT%H-%M-%S"), git_hash))