examples/runwasi: separate cli argument processing for easier reuse

examples/runwasi/CMakeLists.txt

@@ -9,6 +9,7 @@ find_package(toywasm-lib-wasi REQUIRED)
 
 set(sources
 	"runwasi.c"
+	"runwasi_cli_args.c"
 	"main.c"
 )
 

examples/runwasi/main.c

@@ -5,7 +5,6 @@
  * % runwasi --dir=. --env=a=b -- foo.wasm -x -y
  */
 
-#include <getopt.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -14,85 +13,31 @@
 #include <toywasm/xlog.h>
 
 #include "runwasi.h"
-
-enum longopt {
-        opt_wasi_dir,
-        opt_wasi_env,
-};
-
-static const struct option longopts[] = {
-        {
-                "dir",
-                required_argument,
-                NULL,
-                opt_wasi_dir,
-        },
-        {
-                "env",
-                required_argument,
-                NULL,
-                opt_wasi_env,
-        },
-        {
-                NULL,
-                0,
-                NULL,
-                0,
-        },
-};
+#include "runwasi_cli_args.h"
 
 int
 main(int argc, char **argv)
 {
-        unsigned int nenvs = 0;
-        char **envs = NULL;
-        unsigned int ndirs = 0;
-        char **dirs = NULL;
-
-        int ret;
-        int longidx;
-        while ((ret = getopt_long(argc, argv, "", longopts, &longidx)) != -1) {
-                switch (ret) {
-                case opt_wasi_dir:
-                        ndirs++;
-                        dirs = realloc(dirs, ndirs * sizeof(*dirs));
-                        if (dirs == NULL) {
-                                xlog_error("realloc failed");
-                                exit(1);
-                        }
-                        dirs[ndirs - 1] = optarg;
-                        break;
-                case opt_wasi_env:
-                        nenvs++;
-                        envs = realloc(envs, nenvs * sizeof(*envs));
-                        if (envs == NULL) {
-                                xlog_error("realloc failed");
-                                exit(1);
-                        }
-                        envs[nenvs - 1] = optarg;
-                        break;
-                default:
-                        exit(1);
-                }
-        }
-        argc -= optind;
-        argv += optind;
-        if (argc < 1) {
-                xlog_error("unexpected number of args");
-                exit(2);
-        }
-        const char *filename = argv[0];
+        struct runwasi_cli_args a0;
+        struct runwasi_cli_args *a = &a0;
         uint32_t wasi_exit_code;
+        int ret;
         const int stdio_fds[3] = {
                 STDIN_FILENO,
                 STDOUT_FILENO,
                 STDERR_FILENO,
         };
-        ret = runwasi(filename, ndirs, dirs, nenvs, (const char *const *)envs,
-                      argc, (const char *const *)argv, stdio_fds, NULL,
+        ret = runwasi_cli_args_parse(argc, argv, a);
+        if (ret != 0) {
+                xlog_error("failed to process cli arguments");
+                exit(1);
+        }
+        ret = runwasi(a->filename, a->ndirs, a->dirs, a->nenvs,
+                      (const char *const *)a->envs, a->argc,
+                      (const char *const *)a->argv, stdio_fds, NULL,
                       &wasi_exit_code);
-        free(dirs);
-        free(envs);
+        free(a->dirs);
+        free(a->envs);
         if (ret != 0) {
                 exit(1);
         }

examples/runwasi/runwasi_cli_args.c

@@ -0,0 +1,88 @@
+
+#include <getopt.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "runwasi_cli_args.h"
+
+enum longopt {
+        opt_wasi_dir,
+        opt_wasi_env,
+};
+
+static const struct option longopts[] = {
+        {
+                "dir",
+                required_argument,
+                NULL,
+                opt_wasi_dir,
+        },
+        {
+                "env",
+                required_argument,
+                NULL,
+                opt_wasi_env,
+        },
+        {
+                NULL,
+                0,
+                NULL,
+                0,
+        },
+};
+
+int
+runwasi_cli_args_parse(int argc, char **argv, struct runwasi_cli_args *a)
+{
+        unsigned int nenvs = 0;
+        char **envs = NULL;
+        unsigned int ndirs = 0;
+        char **dirs = NULL;
+        void *p;
+
+        int ret;
+        int longidx;
+        while ((ret = getopt_long(argc, argv, "", longopts, &longidx)) != -1) {
+                switch (ret) {
+                case opt_wasi_dir:
+                        ndirs++;
+                        p = realloc(dirs, ndirs * sizeof(*dirs));
+                        if (p == NULL) {
+                                goto fail;
+                        }
+                        dirs = p;
+                        dirs[ndirs - 1] = optarg;
+                        break;
+                case opt_wasi_env:
+                        nenvs++;
+                        p = realloc(envs, nenvs * sizeof(*envs));
+                        if (p == NULL) {
+                                goto fail;
+                        }
+                        envs = p;
+                        envs[nenvs - 1] = optarg;
+                        break;
+                default:
+                        goto fail;
+                }
+        }
+        argc -= optind;
+        argv += optind;
+        if (argc < 1) {
+                goto fail;
+        }
+        const char *filename = argv[0];
+
+        a->filename = filename;
+        a->ndirs = ndirs;
+        a->dirs = dirs;
+        a->nenvs = nenvs;
+        a->envs = envs;
+        a->argc = argc;
+        a->argv = argv;
+        return 0;
+fail:
+        free(envs);
+        free(dirs);
+        return 1;
+}

examples/runwasi/runwasi_cli_args.h

@@ -0,0 +1,12 @@
+
+struct runwasi_cli_args {
+        const char *filename;
+        unsigned int ndirs;
+        char **dirs;
+        unsigned int nenvs;
+        char **envs;
+        int argc;
+        char **argv;
+};
+
+int runwasi_cli_args_parse(int argc, char **argv, struct runwasi_cli_args *a);