From: Jeff Law <jeffreyalaw@gmail.com>
Date: Fri, 29 Oct 2021 15:30:15 +0000 (-0400)
Subject: Avoid overly-greedy match in dejagnu regexp.
X-Git-Tag: basepoints/gcc-13~3524
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=14c7757e9b751781360737f53b71f851fc356d3d;p=thirdparty%2Fgcc.git

Avoid overly-greedy match in dejagnu regexp.

Occasionally I've been seeing failures with the multi-line diagnostics.  It's never been clear what's causing the spurious failures, though I have long suspected a greedy regexp match.

It happened again yesterday with a local change that in no way should affect diagnostics, so I finally went searching and found that sure enough the multi-line diagnostics had a ".*" in their regexp.  According to the comments, the .* is primarily to catch any dg directives that may appear -- ie it should eat to EOL, but not multiple lines.  But a .* can indeed match a newline and cause it to eat multiple lines.

The fix is simple.  [^\r\n]* will eat to EOL, but not further.

Regression tested on x86_64 and on our internal target.

gcc/testsuite

	* lib/multiline.exp (_build_multiline_regex): Use a better
	regexp than .* to match up to EOL.
---

diff --git a/gcc/testsuite/lib/multiline.exp b/gcc/testsuite/lib/multiline.exp
index 0e151b6d2224..86387f8209b8 100644
--- a/gcc/testsuite/lib/multiline.exp
+++ b/gcc/testsuite/lib/multiline.exp
@@ -331,7 +331,7 @@ proc _build_multiline_regex { multiline index } {
 		# Support arbitrary followup text on each non-empty line,
 		# to deal with comments containing containing DejaGnu
 		# directives.
-		append rexp ".*"
+		append rexp "\[^\\n\\r\]*"
 	    }
 	}
 	append rexp "\n"