[cross-project-tests] Fix invalid escape sequences (llvm#94031)

These generate a SyntaxWarning with Python 3.12.

cross-project-tests/debuginfo-tests/dexter/dex/command/ParseCommand.py

@@ -128,7 +128,7 @@ def get_address_object(address_name: str, offset: int = 0):
 
 
 def _search_line_for_cmd_start(line: str, start: int, valid_commands: dict) -> int:
-    """Scan `line` for a string matching any key in `valid_commands`.
+    r"""Scan `line` for a string matching any key in `valid_commands`.
 
     Start searching from `start`.
     Commands escaped with `\` (E.g. `\DexLabel('a')`) are ignored.
@@ -543,7 +543,7 @@ def test_parse_share_line(self):
     def test_parse_escaped(self):
         """Escaped commands are ignored."""
 
-        lines = ['words \MockCmd("IGNORED") words words words\n']
+        lines = ['words \\MockCmd("IGNORED") words words words\n']
 
         values = self._find_all_mock_values_in_lines(lines)
 

cross-project-tests/lit.cfg.py

@@ -223,7 +223,7 @@ def can_target_host():
     xcode_lldb_vers = subprocess.check_output(["xcrun", "lldb", "--version"]).decode(
         "utf-8"
     )
-    match = re.search("lldb-(\d+)", xcode_lldb_vers)
+    match = re.search(r"lldb-(\d+)", xcode_lldb_vers)
     if match:
         apple_lldb_vers = int(match.group(1))
         if apple_lldb_vers < 1000:
@@ -247,7 +247,7 @@ def get_gdb_version_string():
     if len(gdb_vers_lines) < 1:
         print("Unkown GDB version format (too few lines)", file=sys.stderr)
         return None
-    match = re.search("GNU gdb \(.*?\) ((\d|\.)+)", gdb_vers_lines[0].strip())
+    match = re.search(r"GNU gdb \(.*?\) ((\d|\.)+)", gdb_vers_lines[0].strip())
     if match is None:
         print(f"Unkown GDB version format: {gdb_vers_lines[0]}", file=sys.stderr)
         return None
@@ -261,7 +261,7 @@ def get_clang_default_dwarf_version_string(triple):
     # Get the flags passed by the driver and look for -dwarf-version.
     cmd = f'{llvm_config.use_llvm_tool("clang")} -g -xc  -c - -v -### --target={triple}'
     stderr = subprocess.run(cmd.split(), stderr=subprocess.PIPE).stderr.decode()
-    match = re.search("-dwarf-version=(\d+)", stderr)
+    match = re.search(r"-dwarf-version=(\d+)", stderr)
     if match is None:
         print("Cannot determine default dwarf version", file=sys.stderr)
         return None