From 53e793837a36a54e765636b2cefec0c4d92d9a25 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Tue, 3 Aug 2004 23:13:20 +0000 Subject: (struct item, n_strings): Use size_t for sizes. (have_read_stdin, count_items, scan_zeros, detect_loop, recurse_tree, walk_tree, tsort, main): Use bool for booleans. (exit_status): Remove. (tsort): Return a success flag instead of storing into a global. (main): Use it. --- src/tsort.c | 66 ++++++++++++++++++++++++++++++------------------------------- 1 file changed, 32 insertions(+), 34 deletions(-) diff --git a/src/tsort.c b/src/tsort.c index 07a077062..5d12a3db1 100644 --- a/src/tsort.c +++ b/src/tsort.c @@ -54,8 +54,8 @@ struct item { const char *str; struct item *left, *right; - int balance; - int count; + int balance; /* -1, 0, or +1 */ + size_t count; struct item *qlink; struct successor *top; }; @@ -63,11 +63,8 @@ struct item /* The name this program was run with. */ char *program_name; -/* Nonzero if any of the input files are the standard input. */ -static int have_read_stdin; - -/* Nonzero if a nonfatal error has occurred. */ -static int exit_status; +/* True if any of the input files are the standard input. */ +static bool have_read_stdin; /* The head of the sorted list. */ static struct item *head = NULL; @@ -79,7 +76,7 @@ static struct item *zeros = NULL; static struct item *loop = NULL; /* The number of strings to sort. */ -static int n_strings = 0; +static size_t n_strings = 0; static struct option const long_options[] = { @@ -294,14 +291,14 @@ record_relation (struct item *j, struct item *k) } } -static int +static bool count_items (struct item *unused ATTRIBUTE_UNUSED) { n_strings++; - return 0; + return false; } -static int +static bool scan_zeros (struct item *k) { /* Ignore strings that have already been printed. */ @@ -315,12 +312,12 @@ scan_zeros (struct item *k) zeros = k; } - return 0; + return false; } /* Try to detect the loop. If we have detected that K is part of a loop, print the loop on standard error, remove a relation to break - the loop, and return non-zero. + the loop, and return true. The loop detection strategy is as follows: Realise that what we're dealing with is essentially a directed graph. If we find an item @@ -336,7 +333,7 @@ scan_zeros (struct item *k) loop has completely been constructed. If the loop was found, the global variable LOOP will be NULL. */ -static int +static bool detect_loop (struct item *k) { if (k->count > 0) @@ -390,7 +387,7 @@ detect_loop (struct item *k) /* Since we have found the loop, stop walking the tree. */ - return 1; + return true; } else { @@ -405,14 +402,14 @@ detect_loop (struct item *k) } } - return 0; + return false; } /* Recurse (sub)tree rooted at ROOT, calling ACTION for each node. - Stop when ACTION returns non-zero. */ + Stop when ACTION returns true. */ -static int -recurse_tree (struct item *root, int (*action) (struct item *)) +static bool +recurse_tree (struct item *root, bool (*action) (struct item *)) { if (root->left == NULL && root->right == NULL) return (*action) (root); @@ -420,32 +417,33 @@ recurse_tree (struct item *root, int (*action) (struct item *)) { if (root->left != NULL) if (recurse_tree (root->left, action)) - return 1; + return true; if ((*action) (root)) - return 1; + return true; if (root->right != NULL) if (recurse_tree (root->right, action)) - return 1; + return true; } - return 0; + return false; } /* Walk the tree specified by the head ROOT, calling ACTION for each node. */ static void -walk_tree (struct item *root, int (*action) (struct item *)) +walk_tree (struct item *root, bool (*action) (struct item *)) { if (root->right) recurse_tree (root->right, action); } -/* Do a topological sort on FILE. */ +/* Do a topological sort on FILE. Return true if successful. */ -static void +static bool tsort (const char *file) { + bool ok = true; struct item *root; struct item *j = NULL; struct item *k = NULL; @@ -458,7 +456,7 @@ tsort (const char *file) if (STREQ (file, "-")) { fp = stdin; - have_read_stdin = 1; + have_read_stdin = true; } else { @@ -528,12 +526,11 @@ tsort (const char *file) } /* T8. End of process. */ - assert (n_strings >= 0); if (n_strings > 0) { /* The input contains a loop. */ error (0, 0, _("%s: input contains a loop:"), file); - exit_status = 1; + ok = false; /* Print the loop and remove a relation to break it. */ do @@ -541,11 +538,14 @@ tsort (const char *file) while (loop); } } + + return ok; } int main (int argc, char **argv) { + bool ok; int opt; initialize_main (&argc, &argv); @@ -556,8 +556,6 @@ main (int argc, char **argv) atexit (close_stdout); - exit_status = 0; - parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE, VERSION, usage, AUTHORS, (char const *) NULL); @@ -570,7 +568,7 @@ main (int argc, char **argv) usage (EXIT_FAILURE); } - have_read_stdin = 0; + have_read_stdin = false; if (1 < argc - optind) { @@ -578,10 +576,10 @@ main (int argc, char **argv) usage (EXIT_FAILURE); } - tsort (optind == argc ? "-" : argv[optind]); + ok = tsort (optind == argc ? "-" : argv[optind]); if (have_read_stdin && fclose (stdin) == EOF) error (EXIT_FAILURE, errno, _("standard input")); - exit (exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE); + exit (ok ? EXIT_SUCCESS : EXIT_FAILURE); } -- cgit v1.2.3-70-g09d2