From 207cadacd3cef42fa918981423c951f49443f032 Mon Sep 17 00:00:00 2001
From: Rob Landley <rob@landley.net>
Date: Thu, 3 Oct 2013 03:18:00 -0500
Subject: Switch flag generation from shell to C.

This should actually generate FLAG_longopt 0 #defines for disabled bare
longopts (ala ls without --color). Put temporary executables under "generated"
(including instlist for install).
---
 scripts/mkflags.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 129 insertions(+)
 create mode 100644 scripts/mkflags.c

(limited to 'scripts/mkflags.c')

diff --git a/scripts/mkflags.c b/scripts/mkflags.c
new file mode 100644
index 00000000..eca59603
--- /dev/null
+++ b/scripts/mkflags.c
@@ -0,0 +1,129 @@
+// Take three word input lines on stdin (the three space separated words are
+// command name, option string with current config, option string from
+// allyesconfig; space separated, the last two are and double quotes)
+// and produce flag #defines to stdout.
+
+// This is intentionally crappy code because we control the inputs. It leaks
+// memory like a sieve and segfaults if malloc returns null, but does the job.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+struct flag {
+  struct flag *next;
+  char *command;
+  struct flag *lopt;
+};
+
+// Break down a command string into struct flag list.
+
+struct flag *digest(char *string)
+{
+  struct flag *list = NULL;
+
+  while (*string) {
+    // Groups must be at end.
+    if (*string == '[') break;
+
+    // Longopts
+    if (*string == '(') {
+      struct flag *new = calloc(sizeof(struct flag), 1);
+
+      new->command = ++string;
+
+      // Attach longopt to previous short opt, if any.
+      if (list && list->command) {
+        new->next = list->lopt;
+        list->lopt = new;
+      } else {
+        struct flag *blank = calloc(sizeof(struct flag), 1);
+
+        blank->next = list;
+        blank->lopt = new;
+        list = blank;
+      }
+      while (*++string != ')');  // An empty longopt () would break this.
+      *(string++) = 0;
+      continue;
+    }
+
+    if (strchr("?&^-:#|@*; ", *string)) string++;
+    else if (strchr("=<>", *string)) {
+      while (isdigit(*++string)) {
+        if (!list) {
+           string++;
+           break;
+        }
+      }
+    } else {
+      struct flag *new = calloc(sizeof(struct flag), 1);
+
+      new->command = string++;
+      new->next = list;
+      list = new;
+    }
+  }
+
+  return list;
+}
+
+int main(int argc, char *argv[])
+{
+  char command[256], flags[1023], allflags[1024];
+  unsigned bit;
+
+  for (;;) {
+    struct flag *flist, *aflist, *offlist;
+    unsigned bit = 0;
+
+    if (3 != fscanf(stdin, "%255s \"%1023[^\"]\" \"%1023[^\"]\"\n",
+                    command, flags, allflags)) break;
+
+    printf("// %s %s %s\n", command, flags, allflags);
+    flist = digest(flags);
+    offlist = aflist = digest(allflags);
+
+
+    printf("#ifdef CLEANUP_%s\n#undef CLEANUP_%s\n#undef FOR_%s\n#undef TT\n",
+           command, command, command);
+
+    while (offlist) {
+      struct flag *f = offlist->lopt;
+      while (f) {
+        printf("#undef FLAG_%s\n", f->command);
+        f = f->next;
+      }
+      if (offlist->command) printf("#undef FLAG_%c\n", *offlist->command);
+      offlist = offlist->next;
+    }
+    printf("#endif\n\n");
+
+    printf("#ifdef FOR_%s\n#define TT this.%s\n", command, command);
+
+    while (aflist) {
+      if (aflist->lopt) {
+        if (flist && flist->lopt &&
+            !strcmp(flist->lopt->command, aflist->lopt->command))
+        {
+          printf("#define FLAG_%s (1<<%d)\n", flist->lopt->command, bit);
+          flist->lopt = flist->lopt->next;
+        } else printf("#define FLAG_%s 0\n", aflist->lopt->command);
+        aflist->lopt = aflist->lopt->next;
+      } else {
+        if (flist && (!aflist->command || *aflist->command == *flist->command))
+        {
+          if (aflist->command)
+            printf("#define FLAG_%c (1<<%d)\n", *aflist->command, bit);
+          bit++;
+          flist = flist->next;
+        } else printf("#define FLAG_%c 0\n", *aflist->command);
+        aflist = aflist->next;
+      }
+    }
+    printf("#endif\n\n");
+  }
+
+  return fflush(0) && ferror(stdout);
+}
-- 
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