diff: make code more portable

function                                             old     new   delta
create_J                                            1835    1849     +14
diffreg                                             1268    1255     -13

Signed-off-by: Dan Fandrich <dan@coneharvesters.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 40 insertions, 27 deletions

diff --git a/editors/diff.c b/editors/diff.c
index e4d74abca..a8ffcdd8d 100644
--- a/editors/diff.c
+++ b/editors/diff.c
@@ -227,10 +227,12 @@ struct cand {
 
 static int search(const int *c, int k, int y, const struct cand *list)
 {
+        int i, j;
+
         if (list[c[k]].y < y)   /* quick look for typical case */
                 return k + 1;
 
-        for (int i = 0, j = k + 1;;) {
+        for (i = 0, j = k + 1;;) {
                 const int l = (i + j) >> 1;
                 if (l > i) {
                         const int t = list[c[l]].y;
@@ -265,11 +267,13 @@ static void stone(const int *a, int n, const int *b, int *J, int pref)
         int clistlen = 100;
         int k = 0;
         struct cand *clist = xzalloc(clistlen * sizeof(clist[0]));
+        struct cand cand;
+        struct cand *q;
         int *klist = xzalloc((n + 2) * sizeof(klist[0]));
         /*clist[0] = (struct cand){0}; - xzalloc did it */
         /*klist[0] = 0; */
 
-        for (struct cand cand = {1}; cand.x <= n; cand.x++) {
+        for (cand.x = 1; cand.x <= n; cand.x++) {
                 int j = a[cand.x], oldl = 0;
                 unsigned numtries = 0;
                 if (j == 0)
@@ -303,7 +307,7 @@ static void stone(const int *a, int n, const int *b, int *J, int pref)
                 } while ((cand.y = b[++j]) > 0 && numtries < bound);
         }
         /* Unravel */
-        for (struct cand *q = clist + klist[k]; q->y; q = clist + q->pred)
+        for (q = clist + klist[k]; q->y; q = clist + q->pred)
                 J[q->x + pref] = q->y + pref;
         free(klist);
         free(clist);
@@ -348,10 +352,11 @@ static void equiv(struct line *a, int n, struct line *b, int m, int *c)
 
 static void unsort(const struct line *f, int l, int *b)
 {
+        int i;
         int *a = xmalloc((l + 1) * sizeof(a[0]));
-        for (int i = 1; i <= l; i++)
+        for (i = 1; i <= l; i++)
                 a[f[i].serial] = f[i].value;
-        for (int i = 1; i <= l; i++)
+        for (i = 1; i <= l; i++)
                 b[i] = a[i];
         free(a);
 }
@@ -370,12 +375,13 @@ static int line_compar(const void *a, const void *b)
 
 static void fetch(FILE_and_pos_t *ft, const off_t *ix, int a, int b, int ch)
 {
-        for (int i = a; i <= b; i++) {
+        int i, j, col;
+        for (i = a; i <= b; i++) {
                 seek_ft(ft, ix[i - 1]);
                 putchar(ch);
                 if (option_mask32 & FLAG(T))
                         putchar('\t');
-                for (int j = 0, col = 0; j < ix[i] - ix[i - 1]; j++) {
+                for (j = 0, col = 0; j < ix[i] - ix[i - 1]; j++) {
                         int c = fgetc(ft->ft_fp);
                         if (c == EOF) {
                                 printf("\n\\ No newline at end of file\n");
@@ -410,19 +416,20 @@ static NOINLINE int *create_J(FILE_and_pos_t ft[2], int nlen[2], off_t *ix[2])
 {
         int *J, slen[2], *class, *member;
         struct line *nfile[2], *sfile[2];
-        int pref = 0, suff = 0;
+        int pref = 0, suff = 0, i, j, delta;
 
         /* Lines of both files are hashed, and in the process
          * their offsets are stored in the array ix[fileno]
          * where fileno == 0 points to the old file, and
          * fileno == 1 points to the new one.
          */
-        for (int i = 0; i < 2; i++) {
+        for (i = 0; i < 2; i++) {
                 unsigned hash;
                 token_t tok;
                 size_t sz = 100;
                 nfile[i] = xmalloc((sz + 3) * sizeof(nfile[i][0]));
                 /* ft gets here without the correct position, cant use seek_ft */
+                ft[i].ft_pos = 0;
                 fseeko(ft[i].ft_fp, 0, SEEK_SET);
 
                 nlen[i] = 0;
@@ -460,7 +467,7 @@ start:
                         nlen[i]--;
                 /* Now we copy the line offsets into ix */
                 ix[i] = xmalloc((nlen[i] + 2) * sizeof(ix[i][0]));
-                for (int j = 0; j < nlen[i] + 1; j++)
+                for (j = 0; j < nlen[i] + 1; j++)
                         ix[i][j] = nfile[i][j].offset;
         }
 
@@ -475,10 +482,10 @@ start:
          * the result being sorted and stored in sfile[fileno],
          * and their sizes are stored in slen[fileno]
          */
-        for (int j = 0; j < 2; j++) {
+        for (j = 0; j < 2; j++) {
                 sfile[j] = nfile[j] + pref;
                 slen[j] = nlen[j] - pref - suff;
-                for (int i = 0; i <= slen[j]; i++)
+                for (i = 0; i <= slen[j]; i++)
                         sfile[j][i].serial = i;
                 qsort(sfile[j] + 1, slen[j], sizeof(*sfile[j]), line_compar);
         }
@@ -512,7 +519,7 @@ start:
          * are initialized with 0 (no matches), so that function stone can
          * then assign them their right values
          */
-        for (int i = 0, delta = nlen[1] - nlen[0]; i <= nlen[0]; i++)
+        for (i = 0, delta = nlen[1] - nlen[0]; i <= nlen[0]; i++)
                 J[i] = i <= pref            ?  i :
                        i > (nlen[0] - suff) ? (i + delta) : 0;
         /* Here the magic is performed */
@@ -526,14 +533,14 @@ start:
          * which, due to limitations intrinsic to any hashing algorithm,
          * are different but ended up confounded as the same
          */
-        for (int i = 1; i <= nlen[0]; i++) {
+        for (i = 1; i <= nlen[0]; i++) {
                 if (!J[i])
                         continue;
 
                 seek_ft(&ft[0], ix[0][i - 1]);
                 seek_ft(&ft[1], ix[1][J[i] - 1]);
 
-                for (int j = J[i]; i <= nlen[0] && J[i] == j; i++, j++) {
+                for (j = J[i]; i <= nlen[0] && J[i] == j; i++, j++) {
                         token_t tok0 = 0, tok1 = 0;
                         do {
                                 tok0 = read_token(&ft[0], tok0);
@@ -555,13 +562,18 @@ static bool diff(FILE* fp[2], char *file[2])
 {
         int nlen[2];
         off_t *ix[2];
-        FILE_and_pos_t ft[2] = { { fp[0] }, { fp[1] } };
-        int *J = create_J(ft, nlen, ix);
-
-        bool anychange = false;
+        FILE_and_pos_t ft[2];
         typedef struct { int a, b; } vec_t[2];
         vec_t *vec = NULL;
         int i = 1, idx = -1;
+        bool anychange = false;
+        int *J;
+
+        ft[0].ft_fp = fp[0];
+        ft[1].ft_fp = fp[1];
+        /* note that ft[i].ft_pos is unintitalized, create_J()
+         * must not assume otherwise */
+        J = create_J(ft, nlen, ix);
 
         do {
                 bool nonempty = false;
@@ -660,9 +672,9 @@ static int diffreg(char *file[2])
 {
         FILE *fp[2] = { stdin, stdin };
         bool binary = false, differ = false;
-        int status = STATUS_SAME;
+        int status = STATUS_SAME, i;
 
-        for (int i = 0; i < 2; i++) {
+        for (i = 0; i < 2; i++) {
                 int fd = open_or_warn_stdin(file[i]);
                 if (fd == -1)
                         goto out;
@@ -688,7 +700,7 @@ static int diffreg(char *file[2])
                 const size_t sz = COMMON_BUFSIZE / 2;
                 char *const buf0 = bb_common_bufsiz1;
                 char *const buf1 = buf0 + sz;
-                int i, j;
+                int j, k;
                 i = fread(buf0, 1, sz, fp[0]);
                 j = fread(buf1, 1, sz, fp[1]);
                 if (i != j) {
@@ -697,7 +709,7 @@ static int diffreg(char *file[2])
                 }
                 if (i == 0)
                         break;
-                for (int k = 0; k < i; k++) {
+                for (k = 0; k < i; k++) {
                         if (!buf0[k] || !buf1[k])
                                 binary = true;
                         if (buf0[k] != buf1[k])
@@ -771,9 +783,10 @@ static int FAST_FUNC skip_dir(const char *filename,
 static void diffdir(char *p[2], const char *s_start)
 {
         struct dlist list[2];
+        int i;
 
         memset(&list, 0, sizeof(list));
-        for (int i = 0; i < 2; i++) {
+        for (i = 0; i < 2; i++) {
                 /*list[i].s = list[i].e = 0; - memset did it */
                 /*list[i].dl = NULL; */
 
@@ -815,7 +828,7 @@ static void diffdir(char *p[2], const char *s_start)
                 else {
                         char *fullpath[2], *path[2]; /* if -N */
 
-                        for (int i = 0; i < 2; i++) {
+                        for (i = 0; i < 2; i++) {
                                 if (pos == 0 || i == k) {
                                         path[i] = fullpath[i] = concat_path_file(p[i], dp[i]);
                                         stat(fullpath[i], &stb[i]);
@@ -883,7 +896,7 @@ static const char diff_longopts[] ALIGN1 =
 int diff_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int diff_main(int argc UNUSED_PARAM, char **argv)
 {
-        int gotstdin = 0;
+        int gotstdin = 0, i;
         char *file[2], *s_start = NULL;
         llist_t *L_arg = NULL;
 
@@ -900,7 +913,7 @@ int diff_main(int argc UNUSED_PARAM, char **argv)
         while (L_arg)
                 label[!!label[0]] = llist_pop(&L_arg);
         xfunc_error_retval = 2;
-        for (int i = 0; i < 2; i++) {
+        for (i = 0; i < 2; i++) {
                 file[i] = argv[i];
                 /* Compat: "diff file name_which_doesnt_exist" exits with 2 */
                 if (LONE_DASH(file[i])) {