Only emit each filename once in a single .OPTIONAL line when -o is gi…

…ven.

(Saves several MB for kernel .depend files.)

usr.bin/mkdep/mkdep.c

@@ -1,4 +1,4 @@
-/* $NetBSD: mkdep.c,v 1.20 2003/11/11 10:55:24 dsl Exp $ */
+/* $NetBSD: mkdep.c,v 1.21 2003/12/07 20:22:49 dsl Exp $ */
 
 /*-
  * Copyright (c) 1999 The NetBSD Foundation, Inc.
@@ -44,7 +44,7 @@
 #if !defined(lint)
 __COPYRIGHT("@(#) Copyright (c) 1999 The NetBSD Foundation, Inc.\n\
  All rights reserved.\n");
-__RCSID("$NetBSD: mkdep.c,v 1.20 2003/11/11 10:55:24 dsl Exp $");
+__RCSID("$NetBSD: mkdep.c,v 1.21 2003/12/07 20:22:49 dsl Exp $");
 #endif /* not lint */
 
 #include <sys/mman.h>
@@ -63,9 +63,25 @@ __RCSID("$NetBSD: mkdep.c,v 1.20 2003/11/11 10:55:24 dsl Exp $");
 
 #include "findcc.h"
 
+typedef struct opt opt_t;
+struct opt {
+ opt_t *left;
+ opt_t *right;
+ int len;
+ int count;
+ char name[4];
+};
+
+/* tree of includes for -o processing */
+opt_t *opt;
+int width;
+
 #define DEFAULT_PATH _PATH_DEFPATH
 #define DEFAULT_FILENAME ".depend"
 
+static void save_for_optional(const char *, const char *);
+static int write_optional(int, opt_t *, int);
+
 
 static inline void *
 deconst(const void *p)
@@ -264,7 +280,14 @@ main(int argc, char **argv)
  break;
  }
  }
- if (colon != NULL && suffixes != NULL) {
+ if (colon == NULL) {
+ /* No dependency - just transcribe line */
+ write(dependfile, line, eol - line);
+ line = eol;
+ continue;
+ }
+ s = suffixes;
+ if (s != NULL) {
  /* Find the .o: */
  for (suf = colon - 2; ; suf--) {
  if (suf <= line) {
@@ -275,18 +298,12 @@ main(int argc, char **argv)
  continue;
  if (suf[0] != '.' || suf[1] != 'o')
  /* not a file.o: line */
- colon = NULL;
+ s = NULL;
  break;
  }
  }
- if (colon == NULL) {
- /* No dependency - just transcribe line */
- write(dependfile, line, eol - line);
- line = eol;
- continue;
- }
- if (suffixes != NULL) {
- for (s = suffixes; ; s = s1 + 1) {
+ if (s != NULL) {
+ for (; ; s = s1 + 1) {
  s1 = strpbrk(s, ", ");
  if (s1 == NULL)
  s1 = s + strlen(s);
@@ -300,15 +317,93 @@ main(int argc, char **argv)
  } else
  write(dependfile, line, eol - line);
 
- if (oflag) {
- write(dependfile, ".OPTIONAL", 9);
- write(dependfile, colon, eol - colon);
- }
+ if (oflag)
+ save_for_optional(colon + 1, eol);
  line = eol;
  }
  munmap(buf, sz);
  }
+
+ if (oflag && opt != NULL) {
+ write(dependfile, ".OPTIONAL:", 10);
+ width = 9;
+ sz = write_optional(dependfile, opt, 0);
+ /* 'depth' is about 39 for an i386 kernel */
+ /* fprintf(stderr, "Recursion depth %d\n", sz); */
+ }
  close(dependfile);
 
  exit(EXIT_SUCCESS);
 }
+
+
+/*
+ * Only save each file once - the kernel .depend is 3MB and there is
+ * no point doubling its size.
+ * The data seems to be 'random enough' so the simple binary tree
+ * only has a reasonable depth.
+ */
+static void
+save_for_optional(const char *start, const char *limit)
+{
+ opt_t **l, *n;
+ const char *name, *end;
+ int c;
+
+ while (start < limit && strchr(" \t\n\\", *start)) 
+ start++;
+ for (name = start; ; name = end) {
+ while (name < limit && strchr(" \t\n\\", *name)) 
+ name++;
+ for (end = name; end < limit && !strchr(" \t\n\\", *end);)
+ end++;
+ if (name >= limit)
+ break;
+ if (end[-1] == 'c' && end[-2] == '.' && name == start)
+ /* ignore dependency on the files own .c */
+ continue;
+ for (l = &opt;;) {
+ n = *l;
+ if (n == NULL) {
+ n = malloc(sizeof *n + (end - name));
+ n->left = n->right = 0;
+ n->len = end - name;
+ n->count = 1;
+ n->name[0] = ' ';
+ memcpy(n->name + 1, name, end - name);
+ *l = n;
+ break;
+ }
+ c = (end - name) - n->len;
+ if (c == 0)
+ c = memcmp(n->name + 1, name, (end - name));
+ if (c == 0) {
+ /* Duplicate */
+ n->count++;
+ break;
+ }
+ if (c < 0)
+ l = &n->left;
+ else
+ l = &n->right;
+ }
+ }
+}
+
+static int
+write_optional(int fd, opt_t *node, int depth)
+{
+ int d1 = ++depth;
+
+ if (node->left)
+ d1 = write_optional(fd, node->left, d1);
+ if (width > 76 - node->len) {
+ write(fd, " \\\n ", 4);
+ width = 1;
+ }
+ width += 1 + node->len;
+ write(fd, node->name, 1 + node->len);
+ if (node->right)
+ depth = write_optional(fd, node->right, depth);
+ return d1 > depth ? d1 : depth;
+}