Fix lookup_errno by adding a gperf length parameter detection.

build-sys: add check for gperf lookup function signature (#5055)

gperf-3.1 generates lookup functions that take a size_t length
parameter instead of unsigned int. Test for this at configure time.

Fixes: https://github.com/systemd/systemd/issues/5039

3 files changed, 28 insertions, 3 deletions

diff --git a/configure.ac b/configure.ac
index 8e3f7b3cd..24f4d0dd6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -232,7 +232,29 @@ AC_CHECK_SIZEOF(rlim_t,,[
        #include <sys/resource.h>
 ])
 
- # ------------------------------------------------------------------------------
+GPERF_TEST="$(echo foo,bar | ${GPERF} -L ANSI-C)"
+
+AC_COMPILE_IFELSE(
+        [AC_LANG_PROGRAM([
+                #include <string.h>
+                const char * in_word_set(const char *, size_t);
+                $GPERF_TEST]
+        )],
+        [GPERF_LEN_TYPE=size_t],
+        [AC_COMPILE_IFELSE(
+                [AC_LANG_PROGRAM([
+                        #include <string.h>
+                        const char * in_word_set(const char *, unsigned);
+                        $GPERF_TEST]
+                )],
+                [GPERF_LEN_TYPE=unsigned],
+                [AC_MSG_ERROR([** unable to determine gperf len type])]
+        )]
+)
+
+AC_DEFINE_UNQUOTED([GPERF_LEN_TYPE], [$GPERF_LEN_TYPE], [gperf len type])
+
+# ------------------------------------------------------------------------------
 # we use python to build the man page index
 have_python=no
 AC_ARG_WITH([python],
diff --git a/src/basic/errno-list.c b/src/basic/errno-list.c
index fff37eb3e..f7f33bb44 100644
--- a/src/basic/errno-list.c
+++ b/src/basic/errno-list.c
@@ -21,11 +21,13 @@
 
 #include <string.h>
 
+#include "config.h"
 #include "util.h"
 #include "errno-list.h"
 
 static const struct errno_name* lookup_errno(register const char *str,
-                                                 register unsigned int len);
+                                             register GPERF_LEN_TYPE len);
+
 
 #include "errno-to-name.h"
 #include "errno-from-name.h"
diff --git a/src/login/logind.h b/src/login/logind.h
index ff9607413..306709e5b 100644
--- a/src/login/logind.h
+++ b/src/login/logind.h
@@ -24,6 +24,7 @@
 #include <stdbool.h>
 #include <libudev.h>
 
+#include "config.h"
 #include "sd-event.h"
 #include "sd-bus.h"
 #include "list.h"
@@ -179,7 +180,7 @@ int manager_unit_is_active(Manager *manager, const char *unit);
 int manager_job_is_active(Manager *manager, const char *path);
 
 /* gperf lookup function */
-const struct ConfigPerfItem* logind_gperf_lookup (const char *str, size_t len);
+const struct ConfigPerfItem* logind_gperf_lookup(const char *key, GPERF_LEN_TYPE length);
 
 int manager_set_lid_switch_ignore(Manager *m, usec_t until);