Nieuw optieontleedsysteem, en migreer weerklank

3 files changed, 204 insertions, 43 deletions

diff --git a/src/util/option.c b/src/util/option.c
new file mode 100644
index 0000000..ef7a398
--- /dev/null
+++ b/src/util/option.c
@@ -0,0 +1,108 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include "option.h"
+#include "util/versie.h"
+#include "util/debug.h"
+
+
+/* static void debug_argv(int argc, char **argv) {
+  fprintf(stderr, "argv: <");
+  for (int i = 0; i < argc; i++) {
+    if (i != 0) fputc(',', stderr);
+    fprintf(stderr, "'%s'", argv[i]);
+  }
+  fprintf(stderr, ">\n");
+} */
+
+char** option_parse(int argc, char **argv, const struct option_spec *speclist) {
+  // fill table of specs
+  const struct option_spec *spectable[256] = {0};
+  for (const struct option_spec *spec = speclist; spec->kind != OPTSPECKIND_END; spec++) {
+    if (spectable[(uint8_t)spec->optc] != NULL) {
+      fprintf(stderr, "option_parse: dubbele specs\n");
+      abort();
+    }
+    spectable[(uint8_t)spec->optc] = spec;
+  }
+
+  // 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++) {
+    if (argv[opti][0] != '-') continue;  // skip non-options
+
+    // 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 '--'
+
+    for (int j = 1; argv[opti][j]; j++) {
+      const struct option_spec *spec = spectable[(uint8_t)argv[opti][j]];
+      if (!spec) {
+        fprintf(stderr, "%s: Ongeldige optie: -%c\n", argv[0], argv[opti][j]);
+        exit(1);
+      }
+
+      switch (spec->kind) {
+        case OPTSPECKIND_SETBOOL:
+          *spec->spec_sub.setbool.ptr = true;
+          break;
+
+        case OPTSPECKIND_CALL:
+          spec->spec_sub.call.fun();
+          break;
+
+        case OPTSPECKIND_CALLP:
+          spec->spec_sub.callp.fun(spec->spec_sub.callp.data);
+          break;
+
+        case OPTSPECKIND_HELPUSAGE:
+          printf(spec->spec_sub.helpusage.usagestr, argv[0]);
+          exit(0);
+
+        case OPTSPECKIND_VERSION:
+          drukkedoos_print_versie(stdout, argv[0]);
+          exit(0);
+
+        case OPTSPECKIND_END: abort(); // unreachable
+      }
+    }
+  }
+
+  DEBUG("last_option_index=%d npos_before_opts=%d\n", last_option_index, npos_before_opts);
+
+  // debug_argv(argc, argv);
+
+  // 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];
+  }
+
+  // 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 (readi > noptargs + 1) argv[noptargs + 1] = argv[readi];
+      noptargs++;
+    }
+  }
+
+  // debug_argv(argc, argv);
+
+  // write positional arguments after the option arguments
+  memcpy(argv + 1 + noptargs, posargs, npos_before_opts * sizeof(char*));
+
+  // debug_argv(argc, argv);
+
+  return argv + 1 + noptargs;
+}
diff --git a/src/util/option.h b/src/util/option.h
new file mode 100644
index 0000000..780a6e9
--- /dev/null
+++ b/src/util/option.h
@@ -0,0 +1,76 @@
+#pragma once
+
+#include <stdbool.h>
+
+
+enum option_spec_kind {
+  OPTSPECKIND_SETBOOL,
+  OPTSPECKIND_CALL,
+  OPTSPECKIND_CALLP,
+
+  OPTSPECKIND_HELPUSAGE,
+  OPTSPECKIND_VERSION,
+
+  OPTSPECKIND_END,  // end of spec list (rest of spec entry ignored)
+};
+
+// For usage info, see option_parse() below.
+struct option_spec {
+  char optc;  // short option character
+  // TODO: long options?
+
+  // From here, the fields should be filled in using the OPTION_* macros.
+  enum option_spec_kind kind;
+  union {
+    struct { bool *ptr; } setbool;
+    struct { void (*fun)(void); } call;
+    struct { void (*fun)(void*); void *data; } callp;
+    struct { const char *usagestr; } helpusage;
+    struct {} version;
+  } spec_sub;
+};
+
+// Takes a bool* and stores 'true' there if the flag is found.
+#define OPTION_SETBOOL(boolptr) \
+  OPTSPECKIND_SETBOOL, {.setbool={.ptr=(boolptr)}}
+
+// Takes a void(*)(void) and calls it every time the flag is found.
+#define OPTION_CALL(funptr) \
+  OPTSPECKIND_CALL, {.call={.fun=(funptr)}}
+
+// Takes a void(*)(void*) and a 'void *data', and calls the function with 'data'
+// every time the flag is found.
+#define OPTION_CALLP(funptr, dataptr) \
+  OPTSPECKIND_CALLP, {.callp={.fun=(funptr), .data=(dataptr)}}
+
+// 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) \
+  OPTSPECKIND_HELPUSAGE, {.helpusage={.usagestr=(usagestring)}}
+
+// Prints version of the tool and exits with code 0.
+#define OPTION_VERSION() \
+  OPTSPECKIND_VERSION, {.version={}}
+
+// This must be the final entry in the list of option specs; contrary to the
+// other OPTION_* macros, it is an _entire_ 'struct option_spec'.
+#define OPTION_SPEC_END {'\0', OPTSPECKIND_END, {}}
+
+// The spec must not contain duplicate entries for the same short option
+// character.
+// Reshuffles positional arguments to the end of the argument list; returns a
+// pointer to the first positional argument after reshuffling.
+//
+// The specs array is most conveniently declared as a C array:
+//
+//   const struct option_spec[] = {
+//     {'h', OPTION_HELPUSAGE("Gebruik: %s <args>\n")},
+//     {'V', OPTION_VERSION()},
+//     OPTION_SPEC_END
+//   }
+//
+// The individual option specs should be initialised with a brace-initialiser
+// containing the short option character followed by one of the OPTION_* macros,
+// as shown in the example above. See the comments above the macros for their
+// meaning. End the list with OPTION_SPEC_END.
+char** option_parse(int argc, char **argv, const struct option_spec *specs);
diff --git a/src/weerklank.c b/src/weerklank.c
index ad03389..18b8b59 100644
--- a/src/weerklank.c
+++ b/src/weerklank.c
@@ -1,22 +1,17 @@
 #include <stdio.h>
-#include <stdlib.h>
 #include <stdbool.h>
-#include <string.h>
 #include <ctype.h>
-#include <unistd.h>
-#include "util/versie.h"
-
-static void usage(FILE *f) {
-  fprintf(f,
-      "Gebruik: weerklank [-nehV] [touwtje]...\n"
-      "\n"
-      "Exporteer de touwtjes.\n"
-      "\n"
-      "  -n    Voeg geen nieuwe regel toe\n"
-      "  -e    Ontleed terugslagontsnappingen\n"
-      "  -h    Toon deze hulptekst\n"
-      "  -V    Toon versienummer\n");
-}
+#include "util/option.h"
+
+static const char *usage_string =
+  "Gebruik: %s [-nehV] [touwtje]...\n"
+  "\n"
+  "Exporteer de touwtjes.\n"
+  "\n"
+  "  -n    Voeg geen nieuwe regel toe\n"
+  "  -e    Ontleed terugslagontsnappingen\n"
+  "  -h    Toon deze hulptekst\n"
+  "  -V    Toon versienummer\n";
 
 struct options {
   bool nonewline;
@@ -25,33 +20,15 @@ struct options {
 
 // Returns pointer to argument array containing the file names
 static char** parse_options(int argc, char **argv, struct options *opts) {
-  int opt;
-  while ((opt = getopt(argc, argv, "nehV")) != -1) {
-    switch (opt) {
-      case 'n':
-        opts->nonewline = true;
-        break;
-
-      case 'e':
-        opts->unescape = true;
-        break;
-
-      case 'h':
-        usage(stdout);
-        exit(0);
-
-      case 'V':
-        drukkedoos_print_versie(stdout, "weerklank");
-        exit(0);
-
-      case '?':
-        fprintf(stderr, "weerklank: Ongeldige optie: -%c\n", optopt);
-        usage(stderr);
-        exit(1);
-    }
-  }
-
-  return argv + optind;
+  const struct option_spec spec[] = {
+    {'n', OPTION_SETBOOL(&opts->nonewline)},
+    {'e', OPTION_SETBOOL(&opts->unescape)},
+    {'h', OPTION_HELPUSAGE(usage_string)},
+    {'V', OPTION_VERSION()},
+    OPTION_SPEC_END
+  };
+
+  return option_parse(argc, argv, spec);
 }
 
 static const char lowercase_escapes[] = "\a\b\0\0\e\f\0\0\0\0\0\0\0\n\0\0\0\r\0\t\0\v\0\0\0\0";