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diff --git a/docs/TestingGuide.html b/docs/TestingGuide.html index 584b632..df8cfef 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. </p> + <p>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 + <a href="http://www.tcl.tk/man/tcl8.5/TclCmd/exec.htm#M2">Tcl exec</a> + command and the + <a href="http://www.tcl.tk/man/tcl8.5/tutorial/Tcl26.html">tutorial</a>. + The major differences are:</p> + <ul> + <li>You can't do <tt>2>&1</tt>. That will cause Tcl to write to a + file named <tt>&1</tt>. Usually this is done to get stderr to go through + a pipe. You can do that in tcl with <tt>|&</tt> so replace this idiom: + <tt>... 2>&1 | grep</tt> with <tt>... |& grep</tt></li> + <li>You can only redirect to a file, not to another descriptor and not from + a here document.</li> + <li>tcl supports redirecting to open files with the @ syntax but you + shouldn't use that here.</li> + </ul> + <p> Below is an example of legal RUN lines in a <tt>.ll</tt> file:</p> <pre> ; RUN: llvm-as < %s | llvm-dis > %t1 |