From 5a9b04a75b5a5c34811878d75e749318b32ba8a1 Mon Sep 17 00:00:00 2001
From: Curtis McEnroe <june@causal.agency>
Date: Thu, 7 Feb 2019 00:44:06 -0500
Subject: Check subexpressions with hi -c

---
 bin/hi.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

(limited to 'bin')

diff --git a/bin/hi.c b/bin/hi.c
index 7e3a5117..59e6d467 100644
--- a/bin/hi.c
+++ b/bin/hi.c
@@ -246,7 +246,20 @@ int main(int argc, char *argv[]) {
 			regex_t regex = compile(Languages[i].pattern, REG_NOSUB);
 			regfree(&regex);
 			for (size_t j = 0; j < Languages[i].len; ++j) {
-				regex = compile(Languages[i].syntax[j].pattern, REG_NOSUB);
+				struct Syntax syn = Languages[i].syntax[j];
+				regex = compile(syn.pattern, 0);
+				if (regex.re_nsub >= SubsLen) {
+					errx(
+						EX_SOFTWARE,
+						"too many subexpressions: %s", syn.pattern
+					);
+				}
+				if (syn.subexp > regex.re_nsub) {
+					errx(
+						EX_SOFTWARE,
+						"no subexpression %zu: %s", syn.subexp, syn.pattern
+					);
+				}
 				regfree(&regex);
 			}
 		}
-- 
cgit 1.4.1