rtld-elf: add some tests for parse_integer()

Reviewed by:	des, dim
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D57549

libexec/rtld-elf/tests/Makefile

@@ -1,3 +1,5 @@
+#include <src.opts.mk>
+
 SUBDIR+=	libpythagoras libdeep libval libval2 target
 TESTS_SUBDIRS+=	rtld_deepbind
 
@@ -16,6 +18,14 @@ SRCS.$t=	$t.c common.c
 ATF_TESTS_C+=	dlopen_test
 ATF_TESTS_C+=	dlopen_hash_test
 
+ATF_TESTS_C+=	parse_integer_test
+parse_integer_test.c:	parse_integer_func.c
+CFLAGS.parse_integer_test.c+=	-I${.OBJDIR}
+parse_integer_func.c:	${SRCTOP}/libexec/rtld-elf/rtld.c
+	sed  -ne '/^parse_integer/,/^\}/p' ${SRCTOP}/libexec/rtld-elf/rtld.c \
+	    >parse_integer_func.c
+CLEANFILES+=	parse_integer_func.c
+
 WARNS?=		3
 
 .include <bsd.test.mk>

libexec/rtld-elf/tests/parse_integer_test.c

@@ -0,0 +1,35 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright 2026 The FreeBSD Foundation
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ */
+
+#include <limits.h>
+#include <atf-c.h>
+
+static int
+#include "parse_integer_func.c"
+
+ATF_TC_WITHOUT_HEAD(integers);
+ATF_TC_BODY(integers, tc)
+{
+	ATF_REQUIRE_EQ(parse_integer("0"), 0);
+	ATF_REQUIRE_EQ(parse_integer("10"), 10);
+	ATF_REQUIRE_EQ(parse_integer("10001"), 10001);
+	ATF_REQUIRE_EQ(parse_integer("0b101"), 0b101);
+	ATF_REQUIRE_EQ(parse_integer("0x10"), 0x10);
+	ATF_REQUIRE_EQ(parse_integer("020"), 020);
+	ATF_REQUIRE_EQ(parse_integer("090"), -1);
+	/* This test assumes some value for INT_MAX */
+	ATF_REQUIRE_EQ(parse_integer("1111111111111111111111111111"), -1);
+}
+
+ATF_TP_ADD_TCS(tp)
+{
+	ATF_TP_ADD_TC(tp, integers);
+	return (atf_no_error());
+}