[AIX][test/Index] Set/propagate AIXTHREAD_STK for AIX

Summary:
Some tests perform deep recursion, which requires a larger pthread stack
size than the relatively low default of 192 KiB for 64-bit processes on
AIX. The `AIXTHREAD_STK` environment variable provides a non-intrusive
way to request a larger pthread stack size for the tests. The required
pthread stack size depends on the build configuration.

A 4 MiB default is generous compared to the 512 KiB of macOS; however,
it is known that some compilers on AIX produce code that uses
comparatively more stack space.

Reviewers: xingxue, daltenty, jasonliu

Reviewed By: daltenty

Subscribers: arphaman, jfb, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D65688

llvm-svn: 368690

1 files changed, 12 insertions, 0 deletions

diff --git a/clang/test/Index/lit.local.cfg b/clang/test/Index/lit.local.cfg
new file mode 100644
index 00000000000..fb7d197d823
--- /dev/null
+++ b/clang/test/Index/lit.local.cfg
@@ -0,0 +1,12 @@
+import platform
+
+# Some tests perform deep recursion, which requires a larger pthread stack size
+# than the relatively low default of 192 KiB for 64-bit processes on AIX. The
+# `AIXTHREAD_STK` environment variable provides a non-intrusive way to request
+# a larger pthread stack size for the tests. Various applications and runtime
+# libraries on AIX use a default pthread stack size of 4 MiB, so we will use
+# that as a default value here.
+if 'AIXTHREAD_STK' in os.environ:
+    config.environment['AIXTHREAD_STK'] = os.environ['AIXTHREAD_STK']
+elif platform.system() == 'AIX':
+    config.environment['AIXTHREAD_STK'] = '4194304'