Documentation/sphinx: fix Python string escapes

Python 3.6 introduced a DeprecationWarning for invalid escape sequences.
This is upgraded to a SyntaxWarning in Python 3.12, and will eventually
be a syntax error.

Fix these now to get ahead of it before it's an error.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Message-ID: <20230912060801.95533-3-bgray@linux.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/sphinx/cdomain.py

@@ -93,7 +93,7 @@ def markup_ctype_refs(match):
 #
 RE_expr = re.compile(r':c:(expr|texpr):`([^\`]+)`')
 def markup_c_expr(match):
-    return '\ ``' + match.group(2) + '``\ '
+    return '\\ ``' + match.group(2) + '``\\ '
 
 #
 # Parse Sphinx 3.x C markups, replacing them by backward-compatible ones

Documentation/sphinx/kernel_abi.py

@@ -138,7 +138,7 @@ class KernelCmd(Directive):
                 code_block += "\n    " + l
             lines = code_block + "\n\n"
 
-        line_regex = re.compile("^\.\. LINENO (\S+)\#([0-9]+)$")
+        line_regex = re.compile(r"^\.\. LINENO (\S+)\#([0-9]+)$")
         ln = 0
         n = 0
         f = fname

Documentation/sphinx/kernel_feat.py

@@ -104,7 +104,7 @@ class KernelFeat(Directive):
 
         lines = self.runCmd(cmd, shell=True, cwd=cwd, env=shell_env)
 
-        line_regex = re.compile("^\.\. FILE (\S+)$")
+        line_regex = re.compile(r"^\.\. FILE (\S+)$")
 
         out_lines = ""
 

Documentation/sphinx/kerneldoc.py

@@ -130,7 +130,7 @@ class KernelDocDirective(Directive):
             result = ViewList()
 
             lineoffset = 0;
-            line_regex = re.compile("^\.\. LINENO ([0-9]+)$")
+            line_regex = re.compile(r"^\.\. LINENO ([0-9]+)$")
             for line in lines:
                 match = line_regex.search(line)
                 if match:

Documentation/sphinx/maintainers_include.py

@@ -77,7 +77,7 @@ class MaintainersInclude(Include):
             line = line.rstrip()
 
             # Linkify all non-wildcard refs to ReST files in Documentation/.
-            pat = '(Documentation/([^\s\?\*]*)\.rst)'
+            pat = r'(Documentation/([^\s\?\*]*)\.rst)'
             m = re.search(pat, line)
             if m:
                 # maintainers.rst is in a subdirectory, so include "../".
@@ -90,11 +90,11 @@ class MaintainersInclude(Include):
                 output = "| %s" % (line.replace("\\", "\\\\"))
                 # Look for and record field letter to field name mappings:
                 #   R: Designated *reviewer*: FullName <address@domain>
-                m = re.search("\s(\S):\s", line)
+                m = re.search(r"\s(\S):\s", line)
                 if m:
                     field_letter = m.group(1)
                 if field_letter and not field_letter in fields:
-                    m = re.search("\*([^\*]+)\*", line)
+                    m = re.search(r"\*([^\*]+)\*", line)
                     if m:
                         fields[field_letter] = m.group(1)
             elif subsystems:
@@ -112,7 +112,7 @@ class MaintainersInclude(Include):
                     field_content = ""
 
                     # Collapse whitespace in subsystem name.
-                    heading = re.sub("\s+", " ", line)
+                    heading = re.sub(r"\s+", " ", line)
                     output = output + "%s\n%s" % (heading, "~" * len(heading))
                     field_prev = ""
                 else: