Silence Python invalid escape sequence warnings by turning some strings into raw strings

SConstruct

@@ -3623,7 +3623,7 @@ windows_coverage_env = windows_debug_env.Clone(
     #    needed.
     MANIFEST_FILE = None,
     COVERAGE_ANALYZER_DIR=r'..\third_party\coverage_analyzer\bin',
-    COVERAGE_ANALYZER='$COVERAGE_ANALYZER_DIR\coverage_analyzer.exe',
+    COVERAGE_ANALYZER=r'$COVERAGE_ANALYZER_DIR\coverage_analyzer.exe',
 )
 # TODO(bradnelson): Switch nacl to common testing process so this won't be
 #                   needed. Ignoring instrumentation failure as that's easier

site_scons/site_init.py

@@ -129,7 +129,7 @@ def BuildEnvironmentSConscripts(env):
     else:
       raise SCons.Errors.UserError(
           'Bad location for a SConscript. "%s" is not under '
-          '\$TARGET_ROOT or \$MAIN_DIR' % c_script)
+          r'\$TARGET_ROOT or \$MAIN_DIR' % c_script)
 
 def UsingNaclMode():
   build_modes = SCons.Script.ARGUMENTS.get('MODE') or SCons.Script.GetOption('build_mode')

src/trusted/service_runtime/build.scons

@@ -824,7 +824,7 @@ if env.Bit('build_x86_64'):
 
 if env.Bit('build_x86') and env.Bit('nacl_static_link'):
   RE_HELLO = '^(Hello, World!)$'
-  RE_IDENT = '^\[[0-9,:.]*\] (e_ident\+1 = ELF)$'
+  RE_IDENT = r'^\[[0-9,:.]*\] (e_ident\+1 = ELF)$'
 
   node = env.CommandSelLdrTestNacl(
       'nacl_log.out',

tools/command_tester.py

@@ -356,7 +356,7 @@ def GetNaClSignalInfoFromStderr(stderr):
 
   # Scan for signal msg in reverse order
   for curline in reversed(lines):
-    match = re.match('\*\* (Signal|Mach exception) (\d+) from '
+    match = re.match(r'\*\* (Signal|Mach exception) (\d+) from '
                      '(trusted|untrusted) code', str(curline))
     if match is not None:
       return match.group(0)