From 32261735a134418b3bc26fc49d816e487b8338e5 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 28 Dec 2019 14:05:19 +0000
Subject: [PATCH] Warnings: Warn for confusing single-char $ expansions

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 generate | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/generate b/generate
index eb99456..c9ade62 100755
--- a/generate
+++ b/generate
@@ -288,6 +288,10 @@ sub process_input_mk ($$$$) {
 	    } elsif ($2 eq '$') {
 		od $2;
 		if (s{^\$}{}) { od $&; }
+		elsif (m{^[a-zA-Z]\w}) {
+		    wrn
+		    'possibly confusing unbracketed single-char $-expansion';
+		}
 		elsif (m{^\(($esc)?([^()\$]+)\)} ||
 		       m{^\{($esc)?([^{}\$]+)\}}) {
 		    $note_varref->($2,!!$1);
-- 
2.30.2