From 024a126303aef754e1099c822428c44ee6e2bcba Mon Sep 17 00:00:00 2001
From: Reid Spencer
Date: Sat, 14 Apr 2007 23:27:06 +0000
Subject: [PATCH] Add some info about the pipelines and redirection.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36030 91177308-0d34-0410-b5e6-96231b3b80d8
---
docs/TestingGuide.html | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/docs/TestingGuide.html b/docs/TestingGuide.html
index 584b632e04c..df8cfefddf4 100644
--- a/docs/TestingGuide.html
+++ b/docs/TestingGuide.html
@@ -323,6 +323,24 @@ location of these external programs is configured by the llvm-test
any process in the pipeline fails, the entire line (and test case) fails too.
+ As with a Unix shell, the RUN: lines permit pipelines and I/O redirection
+ to be used. However, the usage is slightly different than for Bash. To check
+ what's legal, see the documentation for the
+ Tcl exec
+ command and the
+ tutorial.
+ The major differences are:
+
+ - You can't do 2>&1. That will cause Tcl to write to a
+ file named &1. Usually this is done to get stderr to go through
+ a pipe. You can do that in tcl with |& so replace this idiom:
+ ... 2>&1 | grep with ... |& grep
+ - You can only redirect to a file, not to another descriptor and not from
+ a here document.
+ - tcl supports redirecting to open files with the @ syntax but you
+ shouldn't use that here.
+
+
Below is an example of legal RUN lines in a .ll file:
; RUN: llvm-as < %s | llvm-dis > %t1