[FileCheck] Use lit's internal shell for the test suite

jdenny-ornl · jdenny-ornl · commit 6e418decd936 · 2019-11-19T12:08:54.000-05:00
An advantage is that there are less portability concerns when writing tests. For example, `-u` is not supported by all implementations of `env`, but lit's internal shell provides its own `env` that supports `-u`. A disadvantage is that some shell constructs, such as parentheses, are not supported, but FileCheck's test suite currently doesn't require such constructs. For comparison, lit configures its test suite in the same manner. See `llvm/utils/lit/tests/lit.cfg`. Reviewed By: rnk Differential Revision: https://reviews.llvm.org/D70278
diff --git a/llvm/test/FileCheck/lit.local.cfg b/llvm/test/FileCheck/lit.local.cfg
@@ -1,3 +1,8 @@
+import lit
+
+# Use lit's internal shell to help guarantee test portability.
+config.test_format = lit.formats.ShTest(execute_external=False)
+
 # Unset environment variables that the FileCheck tests
 # expect not to be set.
 file_check_expected_unset_vars = [
