generators: define custom main func definer and use it where applicable

There should be no functional difference, except that the error message
is changd from "three or no arguments" to "zero or three arguments". Somehow
the inverted form always seemed strange.

umask() call is also dropped from run-generator. I think it wasn't dropped in
053254e3cb215df3b8c905bc39b920f8817e1c7d because the run generator was merged
around the same time.

9 files changed, 51 insertions, 93 deletions

diff --git a/src/cryptsetup/cryptsetup-generator.c b/src/cryptsetup/cryptsetup-generator.c
index 746505a181..8759a26148 100644
--- a/src/cryptsetup/cryptsetup-generator.c
+++ b/src/cryptsetup/cryptsetup-generator.c
@@ -13,7 +13,6 @@
 #include "hashmap.h"
 #include "id128-util.h"
 #include "log.h"
-#include "main-func.h"
 #include "mkdir.h"
 #include "parse-util.h"
 #include "path-util.h"
@@ -33,7 +32,7 @@ typedef struct crypto_device {
         bool create;
 } crypto_device;
 
-static const char *arg_dest = "/tmp";
+static const char *arg_dest = NULL;
 static bool arg_enabled = true;
 static bool arg_read_crypttab = true;
 static bool arg_whitelist = false;
@@ -580,16 +579,10 @@ static int add_proc_cmdline_devices(void) {
 DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(crypt_device_hash_ops, char, string_hash_func, string_compare_func,
                                               crypto_device, crypt_device_free);
 
-static int run(int argc, char *argv[]) {
+static int run(const char *dest, const char *dest_early, const char *dest_late) {
         int r;
 
-        log_setup_generator();
-
-        if (argc > 1 && argc != 4)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program takes three or no arguments.");
-
-        if (argc > 1)
-                arg_dest = argv[1];
+        assert_se(arg_dest = dest);
 
         arg_disks = hashmap_new(&crypt_device_hash_ops);
         if (!arg_disks)
@@ -613,4 +606,4 @@ static int run(int argc, char *argv[]) {
         return 0;
 }
 
-DEFINE_MAIN_FUNCTION(run);
+DEFINE_MAIN_GENERATOR_FUNCTION(run);
diff --git a/src/debug-generator/debug-generator.c b/src/debug-generator/debug-generator.c
index 2615aa189d..fa4ca57bbf 100644
--- a/src/debug-generator/debug-generator.c
+++ b/src/debug-generator/debug-generator.c
@@ -2,7 +2,6 @@
 
 #include "alloc-util.h"
 #include "generator.h"
-#include "main-func.h"
 #include "mkdir.h"
 #include "parse-util.h"
 #include "proc-cmdline.h"
@@ -12,8 +11,8 @@
 #include "unit-name.h"
 #include "util.h"
 
+static const char *arg_dest = NULL;
 static char *arg_default_unit = NULL;
-static const char *arg_dest = "/tmp";
 static char **arg_mask = NULL;
 static char **arg_wants = NULL;
 static bool arg_debug_shell = false;
@@ -142,17 +141,10 @@ static int generate_wants_symlinks(void) {
         return r;
 }
 
-static int run(int argc, char *argv[]) {
+static int run(const char *dest, const char *dest_early, const char *dest_late) {
         int r, q;
 
-        log_setup_generator();
-
-        if (argc > 1 && argc != 4)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                       "This program takes three or no arguments.");
-
-        if (argc > 1)
-                arg_dest = argv[2];
+        assert_se(arg_dest = dest_early);
 
         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_RD_STRICT | PROC_CMDLINE_STRIP_RD_PREFIX);
         if (r < 0)
@@ -170,4 +162,4 @@ static int run(int argc, char *argv[]) {
         return r < 0 ? r : q;
 }
 
-DEFINE_MAIN_FUNCTION(run);
+DEFINE_MAIN_GENERATOR_FUNCTION(run);
diff --git a/src/fstab-generator/fstab-generator.c b/src/fstab-generator/fstab-generator.c
index 8acee53d6c..d5e5412059 100644
--- a/src/fstab-generator/fstab-generator.c
+++ b/src/fstab-generator/fstab-generator.c
@@ -40,8 +40,8 @@ typedef enum MountpointFlags {
         GROWFS    = 1 << 4,
 } MountpointFlags;
 
-static const char *arg_dest = "/tmp";
-static const char *arg_dest_late = "/tmp";
+static const char *arg_dest = NULL;
+static const char *arg_dest_late = NULL;
 static bool arg_fstab_enabled = true;
 static char *arg_root_what = NULL;
 static char *arg_root_fstype = NULL;
@@ -868,19 +868,11 @@ static int determine_root(void) {
         return 1;
 }
 
-static int run(int argc, char *argv[]) {
+static int run(const char *dest, const char *dest_early, const char *dest_late) {
         int r;
 
-        log_setup_generator();
-
-        if (argc > 1 && argc != 4)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                       "This program takes three or no arguments.");
-
-        if (argc > 1)
-                arg_dest = argv[1];
-        if (argc > 3)
-                arg_dest_late = argv[3];
+        assert_se(arg_dest = dest);
+        assert_se(arg_dest_late = dest_late);
 
         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
         if (r < 0)
@@ -928,4 +920,4 @@ static int run(int argc, char *argv[]) {
         return r;
 }
 
-DEFINE_MAIN_FUNCTION(run);
+DEFINE_MAIN_GENERATOR_FUNCTION(run);
diff --git a/src/rc-local-generator/rc-local-generator.c b/src/rc-local-generator/rc-local-generator.c
index cd5510bf12..7a3948e92d 100644
--- a/src/rc-local-generator/rc-local-generator.c
+++ b/src/rc-local-generator/rc-local-generator.c
@@ -6,12 +6,11 @@
 
 #include "generator.h"
 #include "log.h"
-#include "main-func.h"
 #include "mkdir.h"
 #include "string-util.h"
 #include "util.h"
 
-static const char *arg_dest = "/tmp";
+static const char *arg_dest = NULL;
 
 /* So you are reading this, and might wonder: why is this implemented as a generator rather than as a plain, statically
  * enabled service that carries appropriate ConditionFileIsExecutable= lines? The answer is this: conditions bypass
@@ -55,16 +54,10 @@ static int check_executable(const char *path) {
         return 0;
 }
 
-static int run(int argc, char *argv[]) {
+static int run(const char *dest, const char *dest_early, const char *dest_late) {
         int r = 0, k = 0;
 
-        log_setup_generator();
-
-        if (argc > 1 && argc != 4)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program takes three or no arguments.");
-
-        if (argc > 1)
-                arg_dest = argv[1];
+        assert_se(arg_dest = dest);
 
         if (check_executable(RC_LOCAL_SCRIPT_PATH_START) >= 0) {
                 log_debug("Automatically adding rc-local.service.");
@@ -81,4 +74,4 @@ static int run(int argc, char *argv[]) {
         return r < 0 ? r : k;
 }
 
-DEFINE_MAIN_FUNCTION(run);
+DEFINE_MAIN_GENERATOR_FUNCTION(run);
diff --git a/src/run-generator/run-generator.c b/src/run-generator/run-generator.c
index 243a426cda..a5dfac01d4 100644
--- a/src/run-generator/run-generator.c
+++ b/src/run-generator/run-generator.c
@@ -5,13 +5,12 @@
 #include "fd-util.h"
 #include "fileio.h"
 #include "generator.h"
-#include "main-func.h"
 #include "mkdir.h"
 #include "proc-cmdline.h"
 #include "specifier.h"
 #include "strv.h"
 
-static const char *arg_dest = "/tmp";
+static const char *arg_dest = NULL;
 static char **arg_commands = NULL;
 static char *arg_success_action = NULL;
 static char *arg_failure_action = NULL;
@@ -122,20 +121,10 @@ static int generate(void) {
         return 0;
 }
 
-static int run(int argc, char *argv[]) {
+static int run(const char *dest, const char *dest_early, const char *dest_late) {
         int r;
 
-        log_setup_generator();
-
-        if (argc > 1 && argc != 4) {
-                log_error("This program takes three or no arguments.");
-                return -EINVAL;
-        }
-
-        if (argc > 1)
-                arg_dest = argv[1];
-
-        umask(0022);
+        assert_se(arg_dest = dest);
 
         r = proc_cmdline_parse(parse, NULL, PROC_CMDLINE_RD_STRICT|PROC_CMDLINE_STRIP_RD_PREFIX);
         if (r < 0)
@@ -144,4 +133,4 @@ static int run(int argc, char *argv[]) {
         return generate();
 }
 
-DEFINE_MAIN_FUNCTION(run);
+DEFINE_MAIN_GENERATOR_FUNCTION(run);
diff --git a/src/shared/generator.h b/src/shared/generator.h
index f1a055401a..5a1c1e32f7 100644
--- a/src/shared/generator.h
+++ b/src/shared/generator.h
@@ -3,6 +3,8 @@
 
 #include <stdio.h>
 
+#include "main-func.h"
+
 int generator_open_unit_file(
         const char *dest,
         const char *source,
@@ -49,3 +51,17 @@ int generator_hook_up_growfs(
         const char *target);
 
 void log_setup_generator(void);
+
+/* Similar to DEFINE_MAIN_FUNCTION, but initializes logging and assigns positional arguments. */
+#define DEFINE_MAIN_GENERATOR_FUNCTION(impl)                            \
+        _DEFINE_MAIN_FUNCTION(                                          \
+                ({                                                      \
+                        log_setup_generator();                          \
+                        if (argc > 1 && argc != 4)                      \
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), \
+                                                       "This program takes zero or three arguments."); \
+                }),                                                     \
+                impl(argc > 1 ? argv[1] : "/tmp",                       \
+                     argc > 1 ? argv[2] : "/tmp",                       \
+                     argc > 1 ? argv[3] : "/tmp"),                      \
+                r < 0 ? EXIT_FAILURE : EXIT_SUCCESS)
diff --git a/src/shared/main-func.h b/src/shared/main-func.h
index ab6b272117..3c182e802b 100644
--- a/src/shared/main-func.h
+++ b/src/shared/main-func.h
@@ -9,10 +9,11 @@
 #include "spawn-polkit-agent.h"
 #include "static-destruct.h"
 
-#define _DEFINE_MAIN_FUNCTION(impl, ret)                                \
+#define _DEFINE_MAIN_FUNCTION(intro, impl, ret)                         \
         int main(int argc, char *argv[]) {                              \
                 int r;                                                  \
-                r = impl(argc, argv);                                   \
+                intro;                                                  \
+                r = impl;                                               \
                 static_destruct();                                      \
                 ask_password_agent_close();                             \
                 polkit_agent_close();                                   \
@@ -24,10 +25,10 @@
 /* Negative return values from impl are mapped to EXIT_FAILURE, and
  * everything else means success! */
 #define DEFINE_MAIN_FUNCTION(impl)                                      \
-        _DEFINE_MAIN_FUNCTION(impl, r < 0 ? EXIT_FAILURE : EXIT_SUCCESS)
+        _DEFINE_MAIN_FUNCTION(,impl(argc, argv), r < 0 ? EXIT_FAILURE : EXIT_SUCCESS)
 
 /* Zero is mapped to EXIT_SUCCESS, negative values are mapped to EXIT_FAILURE,
  * and postive values are propagated.
  * Note: "true" means failure! */
 #define DEFINE_MAIN_FUNCTION_WITH_POSITIVE_FAILURE(impl)                \
-        _DEFINE_MAIN_FUNCTION(impl, r < 0 ? EXIT_FAILURE : r)
+        _DEFINE_MAIN_FUNCTION(,impl(argc, argv), r < 0 ? EXIT_FAILURE : r)
diff --git a/src/sysv-generator/sysv-generator.c b/src/sysv-generator/sysv-generator.c
index c4acdc4a50..514b6e0169 100644
--- a/src/sysv-generator/sysv-generator.c
+++ b/src/sysv-generator/sysv-generator.c
@@ -42,7 +42,7 @@ static const struct {
          * means they are shut down anyway at system power off if running. */
 };
 
-static const char *arg_dest = "/tmp";
+static const char *arg_dest = NULL;
 
 typedef struct SysvStub {
         char *name;
@@ -917,22 +917,14 @@ finish:
         return r;
 }
 
-static int run(int argc, char *argv[]) {
+static int run(const char *dest, const char *dest_early, const char *dest_late) {
         _cleanup_(free_sysvstub_hashmapp) Hashmap *all_services = NULL;
         _cleanup_(lookup_paths_free) LookupPaths lp = {};
         SysvStub *service;
         Iterator j;
         int r;
 
-        log_setup_generator();
-
-        if (argc > 1 && argc != 4) {
-                log_error("This program takes three or no arguments.");
-                return -EINVAL;
-        }
-
-        if (argc > 1)
-                arg_dest = argv[3];
+        assert_se(arg_dest = dest_late);
 
         r = lookup_paths_init(&lp, UNIT_FILE_SYSTEM, LOOKUP_PATHS_EXCLUDE_GENERATED, NULL);
         if (r < 0)
@@ -961,4 +953,4 @@ static int run(int argc, char *argv[]) {
         return 0;
 }
 
-DEFINE_MAIN_FUNCTION(run);
+DEFINE_MAIN_GENERATOR_FUNCTION(run);
diff --git a/src/veritysetup/veritysetup-generator.c b/src/veritysetup/veritysetup-generator.c
index 51996ec37e..65a4e7b0fd 100644
--- a/src/veritysetup/veritysetup-generator.c
+++ b/src/veritysetup/veritysetup-generator.c
@@ -204,16 +204,10 @@ static int determine_devices(void) {
         return 1;
 }
 
-static int run(int argc, char *argv[]) {
+static int run(const char *dest, const char *dest_early, const char *dest_late) {
         int r;
 
-        log_setup_generator();
-
-        if (argc > 1 && argc != 4)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program takes three or no arguments.");
-
-        if (argc > 1)
-                arg_dest = argv[1];
+        assert_se(arg_dest = dest);
 
         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_STRIP_RD_PREFIX);
         if (r < 0)
@@ -229,11 +223,7 @@ static int run(int argc, char *argv[]) {
         if (r < 0)
                 return r;
 
-        r = create_device();
-        if (r < 0)
-                return r;
-
-        return 0;
+        return create_device();
 }
 
-DEFINE_MAIN_FUNCTION(run);
+DEFINE_MAIN_GENERATOR_FUNCTION(run);