[mlir][polly][llvm-lit] Fixed logic for turning on external shell in lit (#106458)

For both mlir and polly, the lit internal shell is the default shell for
running lit tests. However, if the user wanted to switch back to the
external shell by setting `LIT_USE_INTERNAL_SHELL=0`, the `not` used in
the body of the `if` conditional changes `use_lit_shell` to be True
instead of the intended False. Removing `not` allows for this lit config
to work as intended.

Fixes #106459.

Author: connieyzhu

mlir/test/lit.cfg.py

@@ -18,12 +18,15 @@
 # name: The name of this test suite.
 config.name = "MLIR"
 
+# TODO: Consolidate the logic for turning on the internal shell by default for all LLVM test suites.
+# See https://github.com/llvm/llvm-project/issues/106636 for more details.
+#
 # We prefer the lit internal shell which provides a better user experience on failures
 # unless the user explicitly disables it with LIT_USE_INTERNAL_SHELL=0 env var.
 use_lit_shell = True
 lit_shell_env = os.environ.get("LIT_USE_INTERNAL_SHELL")
 if lit_shell_env:
-  use_lit_shell = not lit.util.pythonize_bool(lit_shell_env)
+    use_lit_shell = lit.util.pythonize_bool(lit_shell_env)
 
 config.test_format = lit.formats.ShTest(execute_external=not use_lit_shell)
 

polly/test/UnitIsl/lit.cfg

@@ -17,12 +17,15 @@ config.name = 'Polly - isl unit tests'
 # For now we require '&&' between commands, until they get globally killed and
 # the test runner updated.
 #
+# TODO: Consolidate the logic for turning on the internal shell by default for all LLVM test suites.
+# See https://github.com/llvm/llvm-project/issues/106636 for more details.
+#
 # We prefer the lit internal shell which provides a better user experience on failures
 # unless the user explicitly disables it with LIT_USE_INTERNAL_SHELL=0 env var.
 use_lit_shell = True
 lit_shell_env = os.environ.get("LIT_USE_INTERNAL_SHELL")
 if lit_shell_env:
-  use_lit_shell = not lit.util.pythonize_bool(lit_shell_env)
+	use_lit_shell = lit.util.pythonize_bool(lit_shell_env)
 
 config.test_format = lit.formats.ShTest(execute_external=not use_lit_shell)
 

polly/test/lit.cfg

@@ -20,12 +20,15 @@ config.name = 'Polly'
 # For now we require '&&' between commands, until they get globally killed and
 # the test runner updated.
 #
+# TODO: Consolidate the logic for turning on the internal shell by default for all LLVM test suites.
+# See https://github.com/llvm/llvm-project/issues/106636 for more details.
+#
 # We prefer the lit internal shell which provides a better user experience on failures
 # unless the user explicitly disables it with LIT_USE_INTERNAL_SHELL=0 env var.
 use_lit_shell = True
 lit_shell_env = os.environ.get("LIT_USE_INTERNAL_SHELL")
 if lit_shell_env:
-  use_lit_shell = not lit.util.pythonize_bool(lit_shell_env)
+    use_lit_shell = lit.util.pythonize_bool(lit_shell_env)
 
 config.test_format = lit.formats.ShTest(execute_external=not use_lit_shell)