diff --git a/bolt/test/AArch64/lit.local.cfg b/bolt/test/AArch64/lit.local.cfg
--- a/bolt/test/AArch64/lit.local.cfg
+++ b/bolt/test/AArch64/lit.local.cfg
@@ -1,7 +1,7 @@
-if 'AArch64' not in config.root.targets:
+if "AArch64" not in config.root.targets:
     config.unsupported = True
 
-flags = '--target=aarch64-pc-linux -nostartfiles -nostdlib -ffreestanding'
+flags = "--target=aarch64-pc-linux -nostartfiles -nostdlib -ffreestanding"
 
-config.substitutions.insert(0, ('%cflags', f'%cflags {flags}'))
-config.substitutions.insert(0, ('%cxxflags', f'%cxxflags {flags}'))
+config.substitutions.insert(0, ("%cflags", f"%cflags {flags}"))
+config.substitutions.insert(0, ("%cxxflags", f"%cxxflags {flags}"))
diff --git a/bolt/test/X86/lit.local.cfg b/bolt/test/X86/lit.local.cfg
--- a/bolt/test/X86/lit.local.cfg
+++ b/bolt/test/X86/lit.local.cfg
@@ -1,7 +1,7 @@
-if not 'X86' in config.root.targets:
+if not "X86" in config.root.targets:
     config.unsupported = True
 
-flags = '--target=x86_64-pc-linux -nostdlib'
+flags = "--target=x86_64-pc-linux -nostdlib"
 
-config.substitutions.insert(0, ('%cflags', f'%cflags {flags}'))
-config.substitutions.insert(0, ('%cxxflags', f'%cxxflags {flags}'))
+config.substitutions.insert(0, ("%cflags", f"%cflags {flags}"))
+config.substitutions.insert(0, ("%cxxflags", f"%cxxflags {flags}"))
diff --git a/bolt/test/lit.local.cfg b/bolt/test/lit.local.cfg
--- a/bolt/test/lit.local.cfg
+++ b/bolt/test/lit.local.cfg
@@ -1,6 +1,6 @@
-host_linux_triple = config.target_triple.split('-')[0]+'-linux'
-common_linker_flags = '-fuse-ld=lld -Wl,--unresolved-symbols=ignore-all'
-flags = f'--target={host_linux_triple} {common_linker_flags}'
+host_linux_triple = config.target_triple.split("-")[0] + "-linux"
+common_linker_flags = "-fuse-ld=lld -Wl,--unresolved-symbols=ignore-all"
+flags = f"--target={host_linux_triple} {common_linker_flags}"
 
-config.substitutions.insert(0, ('%cflags', f'%cflags {flags}'))
-config.substitutions.insert(0, ('%cxxflags', f'%cxxflags {flags}'))
+config.substitutions.insert(0, ("%cflags", f"%cflags {flags}"))
+config.substitutions.insert(0, ("%cxxflags", f"%cxxflags {flags}"))
diff --git a/bolt/test/runtime/AArch64/lit.local.cfg b/bolt/test/runtime/AArch64/lit.local.cfg
--- a/bolt/test/runtime/AArch64/lit.local.cfg
+++ b/bolt/test/runtime/AArch64/lit.local.cfg
@@ -1,2 +1,2 @@
-if config.host_arch not in ['aarch64']:
+if config.host_arch not in ["aarch64"]:
     config.unsupported = True
diff --git a/bolt/test/runtime/X86/lit.local.cfg b/bolt/test/runtime/X86/lit.local.cfg
--- a/bolt/test/runtime/X86/lit.local.cfg
+++ b/bolt/test/runtime/X86/lit.local.cfg
@@ -1,2 +1,2 @@
-if config.host_arch not in ['x86', 'X86', 'x86_64']:
+if config.host_arch not in ["x86", "X86", "x86_64"]:
     config.unsupported = True
diff --git a/bolt/test/runtime/lit.local.cfg b/bolt/test/runtime/lit.local.cfg
--- a/bolt/test/runtime/lit.local.cfg
+++ b/bolt/test/runtime/lit.local.cfg
@@ -1,3 +1,3 @@
 # Tests are not expected to pass in a cross-compilation setup.
-if not {'native', 'system-linux'}.issubset(config.available_features):
-  config.unsupported = True
+if not {"native", "system-linux"}.issubset(config.available_features):
+    config.unsupported = True
diff --git a/cross-project-tests/amdgpu/lit.local.cfg b/cross-project-tests/amdgpu/lit.local.cfg
--- a/cross-project-tests/amdgpu/lit.local.cfg
+++ b/cross-project-tests/amdgpu/lit.local.cfg
@@ -1,2 +1,2 @@
-if 'clang' not in config.available_features or 'AMDGPU' not in config.targets_to_build:
+if "clang" not in config.available_features or "AMDGPU" not in config.targets_to_build:
     config.unsupported = True
diff --git a/cross-project-tests/debuginfo-tests/clang_llvm_roundtrip/lit.local.cfg b/cross-project-tests/debuginfo-tests/clang_llvm_roundtrip/lit.local.cfg
--- a/cross-project-tests/debuginfo-tests/clang_llvm_roundtrip/lit.local.cfg
+++ b/cross-project-tests/debuginfo-tests/clang_llvm_roundtrip/lit.local.cfg
@@ -1,3 +1,3 @@
 # In MSVC mode DWARF isn't produced & is needed for these tests
-if 'native' not in config.available_features or config.is_msvc:
+if "native" not in config.available_features or config.is_msvc:
     config.unsupported = True
diff --git a/cross-project-tests/debuginfo-tests/dexter-tests/lit.local.cfg b/cross-project-tests/debuginfo-tests/dexter-tests/lit.local.cfg
--- a/cross-project-tests/debuginfo-tests/dexter-tests/lit.local.cfg
+++ b/cross-project-tests/debuginfo-tests/dexter-tests/lit.local.cfg
@@ -1,2 +1,2 @@
-if 'dexter' not in config.available_features:
+if "dexter" not in config.available_features:
     config.unsupported = True
diff --git a/cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/lit.local.cfg b/cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/lit.local.cfg
--- a/cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/lit.local.cfg
+++ b/cross-project-tests/debuginfo-tests/dexter/feature_tests/commands/perfect/limit_steps/lit.local.cfg
@@ -1,4 +1,3 @@
 # The dbgeng driver doesn't support DexLimitSteps yet.
 if config.is_msvc:
     config.unsupported = True
-
diff --git a/cross-project-tests/debuginfo-tests/dexter/feature_tests/lit.local.cfg b/cross-project-tests/debuginfo-tests/dexter/feature_tests/lit.local.cfg
--- a/cross-project-tests/debuginfo-tests/dexter/feature_tests/lit.local.cfg
+++ b/cross-project-tests/debuginfo-tests/dexter/feature_tests/lit.local.cfg
@@ -1,5 +1,5 @@
-if 'dexter' not in config.available_features:
+if "dexter" not in config.available_features:
     config.unsupported = True
 
 config.name = "DExTer feature tests"
-config.suffixes = ['.cpp', '.c', '.test']
+config.suffixes = [".cpp", ".c", ".test"]
diff --git a/cross-project-tests/debuginfo-tests/lit.local.cfg b/cross-project-tests/debuginfo-tests/lit.local.cfg
--- a/cross-project-tests/debuginfo-tests/lit.local.cfg
+++ b/cross-project-tests/debuginfo-tests/lit.local.cfg
@@ -1,2 +1,2 @@
-if 'clang' not in config.available_features:
+if "clang" not in config.available_features:
     config.unsupported = True
diff --git a/cross-project-tests/debuginfo-tests/llgdb-tests/lit.local.cfg b/cross-project-tests/debuginfo-tests/llgdb-tests/lit.local.cfg
--- a/cross-project-tests/debuginfo-tests/llgdb-tests/lit.local.cfg
+++ b/cross-project-tests/debuginfo-tests/llgdb-tests/lit.local.cfg
@@ -1,5 +1,3 @@
 # debuginfo-tests are not expected to pass in a cross-compilation setup.
-if 'native' not in config.available_features or config.is_msvc:
+if "native" not in config.available_features or config.is_msvc:
     config.unsupported = True
-
-
diff --git a/cross-project-tests/debuginfo-tests/llvm-prettyprinters/gdb/lit.local.cfg b/cross-project-tests/debuginfo-tests/llvm-prettyprinters/gdb/lit.local.cfg
--- a/cross-project-tests/debuginfo-tests/llvm-prettyprinters/gdb/lit.local.cfg
+++ b/cross-project-tests/debuginfo-tests/llvm-prettyprinters/gdb/lit.local.cfg
@@ -1,13 +1,11 @@
 import lit.util
 
 # debuginfo-tests are not expected to pass in a cross-compilation setup.
-if 'native' not in config.available_features or lit.util.which('gdb') is None:
+if "native" not in config.available_features or lit.util.which("gdb") is None:
     config.unsupported = True
 
 if config.mlir_src_root:
-  config.substitutions.append(("%mlir_src_root", config.mlir_src_root))
-  config.available_features.add('mlir')
-
-config.suffixes = ['.gdb']
-
+    config.substitutions.append(("%mlir_src_root", config.mlir_src_root))
+    config.available_features.add("mlir")
 
+config.suffixes = [".gdb"]
diff --git a/cross-project-tests/intrinsic-header-tests/lit.local.cfg b/cross-project-tests/intrinsic-header-tests/lit.local.cfg
--- a/cross-project-tests/intrinsic-header-tests/lit.local.cfg
+++ b/cross-project-tests/intrinsic-header-tests/lit.local.cfg
@@ -1,2 +1,2 @@
-if 'clang' not in config.available_features:
+if "clang" not in config.available_features:
     config.unsupported = True
diff --git a/flang/test/lib/lit.local.cfg b/flang/test/lib/lit.local.cfg
--- a/flang/test/lib/lit.local.cfg
+++ b/flang/test/lib/lit.local.cfg
@@ -1,7 +1,28 @@
-
-# Excluding .cpp file from the extensions since from this level down they are used for the development 
-config.suffixes = ['.c', '.f', '.F', '.ff', '.FOR', '.for', '.f77', '.f90', '.F90',
-                   '.ff90', '.f95', '.F95', '.ff95', '.fpp', '.FPP', '.cuf'
-                   '.CUF', '.f18', '.F18', '.f03', '.F03', '.f08', '.F08',
-                   '.ll', '.fir', '.mlir']
-
+# Excluding .cpp file from the extensions since from this level down they are used for the development
+config.suffixes = [
+    ".c",
+    ".f",
+    ".F",
+    ".ff",
+    ".FOR",
+    ".for",
+    ".f77",
+    ".f90",
+    ".F90",
+    ".ff90",
+    ".f95",
+    ".F95",
+    ".ff95",
+    ".fpp",
+    ".FPP",
+    ".cuf" ".CUF",
+    ".f18",
+    ".F18",
+    ".f03",
+    ".F03",
+    ".f08",
+    ".F08",
+    ".ll",
+    ".fir",
+    ".mlir",
+]
diff --git a/lld/test/COFF/lit.local.cfg b/lld/test/COFF/lit.local.cfg
--- a/lld/test/COFF/lit.local.cfg
+++ b/lld/test/COFF/lit.local.cfg
@@ -1 +1 @@
-config.environment['LLD_IN_TEST'] = '2'
+config.environment["LLD_IN_TEST"] = "2"
diff --git a/lld/test/ELF/lit.local.cfg b/lld/test/ELF/lit.local.cfg
--- a/lld/test/ELF/lit.local.cfg
+++ b/lld/test/ELF/lit.local.cfg
@@ -1,8 +1,8 @@
-config.suffixes = ['.test', '.s', '.ll', '.bat']
+config.suffixes = [".test", ".s", ".ll", ".bat"]
 
 # The environment variable DFLTCC=0 disables use of the hardware compression
 # facility on SystemZ.  When this facility is enabled, slightly different
 # compression results can be seen, which can cause spurious failures in the
 # compressed-debug-level.test test case.
-if 's390x' in config.host_triple:
-    config.environment['DFLTCC'] = '0'
+if "s390x" in config.host_triple:
+    config.environment["DFLTCC"] = "0"
diff --git a/lld/test/MachO/lit.local.cfg b/lld/test/MachO/lit.local.cfg
--- a/lld/test/MachO/lit.local.cfg
+++ b/lld/test/MachO/lit.local.cfg
@@ -5,7 +5,7 @@
 # FIXME: The MachO back-end currently does not respect endianness when
 # accessing binary data structures, and therefore only works correctly
 # on little-endian host systems.  Skip all tests on big-endian hosts.
-if sys.byteorder == 'big':
+if sys.byteorder == "big":
     config.unsupported = True
 
 # We specify the most commonly-used archs and platform versions in our tests
@@ -16,17 +16,21 @@
 # flag will append to the set of library roots. As such, we define a separate
 # alias for each platform.
 
-lld_watchos = ('ld64.lld -lSystem -arch arm64_32 -platform_version watchos 7.0 8.0 -syslibroot ' +
-    os.path.join(config.test_source_root, "MachO", "Inputs", "WatchOS.sdk"))
-config.substitutions.append(('%lld-watchos', lld_watchos + ' -fatal_warnings'))
-config.substitutions.append(('%no-fatal-warnings-lld-watchos', lld_watchos))
+lld_watchos = (
+    "ld64.lld -lSystem -arch arm64_32 -platform_version watchos 7.0 8.0 -syslibroot "
+    + os.path.join(config.test_source_root, "MachO", "Inputs", "WatchOS.sdk")
+)
+config.substitutions.append(("%lld-watchos", lld_watchos + " -fatal_warnings"))
+config.substitutions.append(("%no-fatal-warnings-lld-watchos", lld_watchos))
 
-config.substitutions.append(('%no-arg-lld', 'ld64.lld'))
+config.substitutions.append(("%no-arg-lld", "ld64.lld"))
 
 # Since most of our tests are written around x86_64, we give this platform the
 # shortest substitution of "%lld".
-lld = ('ld64.lld -arch x86_64 -platform_version macos 11.0 11.0 -syslibroot ' +
-    os.path.join(config.test_source_root, "MachO", "Inputs", "MacOSX.sdk"))
-config.substitutions.append(('%lld', lld + ' -lSystem -fatal_warnings'))
-config.substitutions.append(('%no-lsystem-lld', lld + ' -fatal_warnings'))
-config.substitutions.append(('%no-fatal-warnings-lld', lld + ' -lSystem'))
+lld = (
+    "ld64.lld -arch x86_64 -platform_version macos 11.0 11.0 -syslibroot "
+    + os.path.join(config.test_source_root, "MachO", "Inputs", "MacOSX.sdk")
+)
+config.substitutions.append(("%lld", lld + " -lSystem -fatal_warnings"))
+config.substitutions.append(("%no-lsystem-lld", lld + " -fatal_warnings"))
+config.substitutions.append(("%no-fatal-warnings-lld", lld + " -lSystem"))
diff --git a/lld/test/wasm/lit.local.cfg b/lld/test/wasm/lit.local.cfg
--- a/lld/test/wasm/lit.local.cfg
+++ b/lld/test/wasm/lit.local.cfg
@@ -1,4 +1,4 @@
-if 'wasm' not in config.available_features:
-  config.unsupported = True
+if "wasm" not in config.available_features:
+    config.unsupported = True
 
-config.suffixes = ['.test', '.yaml', '.ll', '.s']
+config.suffixes = [".test", ".yaml", ".ll", ".s"]
diff --git a/pstl/test/std/lit.local.cfg b/pstl/test/std/lit.local.cfg
--- a/pstl/test/std/lit.local.cfg
+++ b/pstl/test/std/lit.local.cfg
@@ -1,2 +1,2 @@
-if 'parallel-algorithms' not in config.available_features:
+if "parallel-algorithms" not in config.available_features:
     config.unsupported = True