[llvm] Document "%T" as deprecated in TestingGuide.rst
Differential Revision: https://reviews.llvm.org/D48189
llvm-svn: 335080
diff --git a/llvm/docs/TestingGuide.rst b/llvm/docs/TestingGuide.rst
index a27da0d..3cc8cf4 100644
--- a/llvm/docs/TestingGuide.rst
+++ b/llvm/docs/TestingGuide.rst
@@ -460,7 +460,10 @@
Example: ``/home/user/llvm.build/test/MC/ELF/Output/foo_test.s.tmp``
``%T``
- Directory of ``%t``.
+ Directory of ``%t``. Deprecated. Shouldn't be used, because it can be easily
+ misused and cause race conditions between tests.
+
+ Use ``rm -rf %t && mkdir %t`` instead if a temporary directory is necessary.
Example: ``/home/user/llvm.build/test/MC/ELF/Output``