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>

diff --git a/editors/diff.c b/editors/diff.c
index e4d74abca2a879d556d7b9945ccaa5d88af1c4c1..a8ffcdd8dc6368264da5a09dd678c9731aa45ea5 100644 (file)
--- 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])) {