From d244e4e3cb702dcb87f1c3c1232abd2fc936d8ec Mon Sep 17 00:00:00 2001
From: Tom Smeding <tom@tomsmeding.com>
Date: Sun, 8 Sep 2024 22:02:02 +0200
Subject: OPTION_WITHARG

---
 src/util/option.c | 51 ++++++++++++++++++++++++++++++++++++++++++++-------
 src/util/option.h |  8 ++++++++
 2 files changed, 52 insertions(+), 7 deletions(-)

diff --git a/src/util/option.c b/src/util/option.c
index 5efcbd7..2ad20d1 100644
--- a/src/util/option.c
+++ b/src/util/option.c
@@ -25,21 +25,34 @@ char** option_parse(int argc, char **argv, const struct option_spec *speclist) {
       abort();
     }
     spectable[(uint8_t)spec->optc] = spec;
+
+    if (spec->kind == OPTSPECKIND_WITHARG) {
+      *spec->spec_sub.witharg.dst = NULL;
+    }
   }
 
+  // option, option argument, or '--'.
+  bool *is_option = calloc(argc, 1);
+
   // parse options
   int last_option_index = 0;  // index of last option argument, treating '--' as option arg
   int npos_before_opts = 0;  // number of positional arguments before last_option_index
   int opti;
   for (opti = 1; opti < argc; opti++) {
+    DEBUG("opti = %d\n", opti);
+
     if (argv[opti][0] != '-') continue;  // skip non-options
 
+    is_option[opti] = true;
+
     // count an option argument even if it's '--'
     npos_before_opts += opti - (last_option_index + 1);
     last_option_index = opti;
 
     if (strcmp(argv[opti], "--") == 0) break;  // but don't try to parse '--'
 
+    bool skip_next_argument = false;
+
     for (int j = 1; argv[opti][j]; j++) {
       const struct option_spec *spec = spectable[(uint8_t)argv[opti][j]];
       if (!spec) {
@@ -60,6 +73,27 @@ char** option_parse(int argc, char **argv, const struct option_spec *speclist) {
           spec->spec_sub.callp.fun(spec->spec_sub.callp.data);
           break;
 
+        case OPTSPECKIND_WITHARG:
+          if (argv[opti][j+1] != '\0') {
+            fprintf(stderr, "%s: Optie -%c heeft een argument nodig, maar is niet de laatste op rij\n", argv[0], argv[opti][j]);
+            exit(1);
+          }
+
+          if (opti + 1 < argc) {
+            char **dst = spec->spec_sub.witharg.dst;
+            if (*dst) free(*dst);  // override any previous value
+
+            const size_t arglen = strlen(argv[opti+1]);
+            *dst = malloc(arglen + 1);
+            memcpy(*dst, argv[opti+1], arglen + 1);
+
+            skip_next_argument = true;
+          } else {
+            fprintf(stderr, "%s: Optie -%c heeft een argument nodig\n", argv[0], argv[opti][j]);
+            exit(1);
+          }
+          break;
+
         case OPTSPECKIND_HELPUSAGE:
           printf(spec->spec_sub.helpusage.usagestr, argv[0]);
           exit(0);
@@ -71,6 +105,12 @@ char** option_parse(int argc, char **argv, const struct option_spec *speclist) {
         case OPTSPECKIND_END: abort(); // unreachable
       }
     }
+
+    if (skip_next_argument) {
+      // skip next argument, but mark it as an option
+      last_option_index = ++opti;
+      is_option[opti] = true;
+    }
   }
 
   DEBUG("last_option_index=%d npos_before_opts=%d\n", last_option_index, npos_before_opts);
@@ -80,18 +120,13 @@ char** option_parse(int argc, char **argv, const struct option_spec *speclist) {
   // collect positional arguments that need to be reshuffled
   char *posargs[npos_before_opts];
   for (int i = 1, posi = 0; i < last_option_index; i++) {
-    // don't need to check for '--' here because '--' is an option argument and
-    // this loop doesn't go beyond it
-    if (argv[i][0] == '-') continue;
-
-    posargs[posi++] = argv[i];
+    if (!is_option[i]) posargs[posi++] = argv[i];
   }
 
   // move option arguments to the beginning
   int noptargs = 0;
   for (int readi = 1; readi <= last_option_index; readi++) {
-    // no need to check for '--' here
-    if (argv[readi][0] == '-') {
+    if (is_option[readi]) {
       if (readi > noptargs + 1) argv[noptargs + 1] = argv[readi];
       noptargs++;
     }
@@ -104,5 +139,7 @@ char** option_parse(int argc, char **argv, const struct option_spec *speclist) {
 
   // debug_argv(argc, argv);
 
+  free(is_option);
+
   return argv + 1 + noptargs;
 }
diff --git a/src/util/option.h b/src/util/option.h
index 780a6e9..a5a698b 100644
--- a/src/util/option.h
+++ b/src/util/option.h
@@ -7,6 +7,7 @@ enum option_spec_kind {
   OPTSPECKIND_SETBOOL,
   OPTSPECKIND_CALL,
   OPTSPECKIND_CALLP,
+  OPTSPECKIND_WITHARG,
 
   OPTSPECKIND_HELPUSAGE,
   OPTSPECKIND_VERSION,
@@ -25,6 +26,7 @@ struct option_spec {
     struct { bool *ptr; } setbool;
     struct { void (*fun)(void); } call;
     struct { void (*fun)(void*); void *data; } callp;
+    struct { char **dst; } witharg;
     struct { const char *usagestr; } helpusage;
     struct {} version;
   } spec_sub;
@@ -43,6 +45,12 @@ struct option_spec {
 #define OPTION_CALLP(funptr, dataptr) \
   OPTSPECKIND_CALLP, {.callp={.fun=(funptr), .data=(dataptr)}}
 
+// An option with an argument. Takes a char** and stores a newly malloc()ed
+// string in that pointer for the given argument. Later occurrences override any
+// previous ones, and NULL is written if the option never occurs.
+#define OPTION_WITHARG(argptr) \
+  OPTSPECKIND_WITHARG, {.witharg={.dst=(argptr)}}
+
 // Takes a printf format string with a single %s, which is substituted (by
 // printf) for argv[0]. Prints the formatted string and exits with code 0.
 #define OPTION_HELPUSAGE(usagestring) \
-- 
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