diff options
Diffstat (limited to 'dir.c')
| -rw-r--r-- | dir.c | 401 |
1 files changed, 401 insertions, 0 deletions
@@ -0,0 +1,401 @@ +/* Directory hashing for GNU Make. +Copyright (C) 1988, 1989, 1991 Free Software Foundation, Inc. +This file is part of GNU Make. + +GNU Make is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Make is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Make; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include "make.h" + +#if defined (USGr3) && !defined (DIRENT) +#define DIRENT +#endif /* USGr3 */ +#if defined (Xenix) && !defined (SYSNDIR) +#define SYSNDIR +#endif /* Xenix */ + +#if defined (POSIX) || defined (DIRENT) || defined (__GNU_LIBRARY__) +#include <dirent.h> +#define direct dirent +#define D_NAMLEN(d) strlen((d)->d_name) +#else /* not POSIX or DIRENT */ +#define D_NAMLEN(d) ((d)->d_namlen) +#if defined (USG) && !defined (sgi) +#if defined (SYSNDIR) +#include <sys/ndir.h> +#else /* SYSNDIR */ +#include "ndir.h" +#endif /* not SYSNDIR */ +#else /* not USG */ +#include <sys/dir.h> +#endif /* USG */ +#endif /* POSIX or DIRENT or __GNU_LIBRARY__ */ + +#if defined (POSIX) && !defined (__GNU_LIBRARY__) +/* Posix does not require that the d_ino field be present, and some + systems do not provide it. */ +#define REAL_DIR_ENTRY(dp) 1 +#else +#define REAL_DIR_ENTRY(dp) (dp->d_ino != 0) +#endif /* POSIX */ + +/* Hash table of directories. */ + +struct directory + { + struct directory *next; + char *name; /* Name of the directory. */ + struct dirfile **files; /* Files in this directory. */ + DIR *dirstream; /* Stream reading this directory. */ + }; + +#ifndef DIRECTORY_BUCKETS +#define DIRECTORY_BUCKETS 23 +#endif + +static struct directory *directories[DIRECTORY_BUCKETS]; + + +/* Never have more than this many directories open at once. */ + +#define MAX_OPEN_DIRECTORIES 10 + +static unsigned int open_directories = 0; + + +/* Hash table of files in each directory. */ + +struct dirfile + { + struct dirfile *next; + char *name; /* Name of the file. */ + char impossible; /* This file is impossible. */ + }; + +#ifndef DIRFILE_BUCKETS +#define DIRFILE_BUCKETS 1007 +#endif + +/* Find the directory named NAME and return its `struct directory'. */ + +static struct directory * +find_directory (name) + register char *name; +{ + register unsigned int hash = 0; + register char *p; + register struct directory *dir; + + for (p = name; *p != '\0'; ++p) + HASH (hash, *p); + hash %= DIRECTORY_BUCKETS; + + for (dir = directories[hash]; dir != 0; dir = dir->next) + if (streq (dir->name, name)) + break; + + if (dir == 0) + { + /* The directory was not found. Create a new entry + for it and start its directory stream reading. */ + dir = (struct directory *) xmalloc (sizeof (struct directory)); + dir->next = directories[hash]; + directories[hash] = dir; + dir->name = savestring (name, p - name); + dir->dirstream = opendir (name); + if (dir->dirstream == 0) + /* Couldn't open the directory. Mark this by + setting the `files' member to a nil pointer. */ + dir->files = 0; + else + { + /* Allocate an array of hash buckets for files and zero it. */ + dir->files = (struct dirfile **) + xmalloc (sizeof (struct dirfile) * DIRFILE_BUCKETS); + bzero ((char *) dir->files, + sizeof (struct dirfile) * DIRFILE_BUCKETS); + + /* Keep track of how many directories are open. */ + ++open_directories; + if (open_directories == MAX_OPEN_DIRECTORIES) + /* Read the entire directory and then close it. */ + (void) dir_file_exists_p (dir->name, (char *) 0); + } + } + + return dir; +} + +/* Return 1 if the name FILENAME in directory DIRNAME + is entered in the dir hash table. + FILENAME must contain no slashes. */ + +int +dir_file_exists_p (dirname, filename) + register char *dirname; + register char *filename; +{ + register unsigned int hash; + register char *p; + register struct directory *dir; + register struct dirfile *df; + register struct direct *d; + dir = find_directory (dirname); + + if (dir->files == 0) + /* The directory could not be opened. */ + return 0; + + hash = 0; + if (filename != 0) + { + if (*filename == '\0') + /* Checking if the directory exists. */ + return 1; + + for (p = filename; *p != '\0'; ++p) + HASH (hash, *p); + hash %= DIRFILE_BUCKETS; + + /* Search the list of hashed files. */ + + for (df = dir->files[hash]; df != 0; df = df->next) + if (streq (df->name, filename)) + return !df->impossible; + } + + /* The file was not found in the hashed list. + Try to read the directory further. */ + + if (dir->dirstream == 0) + /* The directory has been all read in. */ + return 0; + + while ((d = readdir (dir->dirstream)) != 0) + { + /* Enter the file in the hash table. */ + register unsigned int newhash = 0; + register unsigned int i; + + if (!REAL_DIR_ENTRY (d)) + continue; + + for (i = 0; i < D_NAMLEN(d); ++i) + HASH (newhash, d->d_name[i]); + newhash %= DIRFILE_BUCKETS; + + df = (struct dirfile *) xmalloc (sizeof (struct dirfile)); + df->next = dir->files[newhash]; + dir->files[newhash] = df; + df->name = savestring (d->d_name, D_NAMLEN(d)); + df->impossible = 0; + + /* Check if the name matches the one we're searching for. */ + if (filename != 0 + && newhash == hash && streq (d->d_name, filename)) + return 1; + } + + /* If the directory has been completely read in, + close the stream and reset the pointer to nil. */ + if (d == 0) + { + --open_directories; + closedir (dir->dirstream); + dir->dirstream = 0; + } + + return 0; +} + +/* Return 1 if the file named NAME exists. */ + +int +file_exists_p (name) + register char *name; +{ + char *dirend; + char *dirname; + +#ifndef NO_ARCHIVES + if (ar_name (name)) + return ar_member_date (name) != (time_t) -1; +#endif + + dirend = rindex (name, '/'); + if (dirend == 0) + return dir_file_exists_p (".", name); + + dirname = (char *) alloca (dirend - name + 1); + bcopy (name, dirname, dirend - name); + dirname[dirend - name] = '\0'; + return dir_file_exists_p (dirname, dirend + 1); +} + +/* Mark FILENAME as `impossible' for `file_impossible_p'. + This means an attempt has been made to search for FILENAME + as an intermediate file, and it has failed. */ + +void +file_impossible (filename) + register char *filename; +{ + char *dirend; + register char *p = filename; + register unsigned int hash; + register struct directory *dir; + register struct dirfile *new; + + dirend = rindex (p, '/'); + if (dirend == 0) + dir = find_directory ("."); + else + { + char *dirname = (char *) alloca (dirend - p + 1); + bcopy (p, dirname, dirend - p); + dirname[dirend - p] = '\0'; + dir = find_directory (dirname); + filename = p = dirend + 1; + } + + for (hash = 0; *p != '\0'; ++p) + HASH (hash, *p); + hash %= DIRFILE_BUCKETS; + + if (dir->files == 0) + { + /* The directory was not opened; we must allocate the hash buckets. */ + dir->files = (struct dirfile **) + xmalloc (sizeof (struct dirfile) * DIRFILE_BUCKETS); + bzero ((char *) dir->files, sizeof (struct dirfile) * DIRFILE_BUCKETS); + } + + /* Make a new entry and put it in the table. */ + + new = (struct dirfile *) xmalloc (sizeof (struct dirfile)); + new->next = dir->files[hash]; + dir->files[hash] = new; + new->name = savestring (filename, strlen (filename)); + new->impossible = 1; +} + +/* Return nonzero if FILENAME has been marked impossible. */ + +int +file_impossible_p (filename) + char *filename; +{ + char *dirend; + register char *p = filename; + register unsigned int hash; + register struct directory *dir; + register struct dirfile *next; + + dirend = rindex (filename, '/'); + if (dirend == 0) + dir = find_directory ("."); + else + { + char *dirname = (char *) alloca (dirend - filename + 1); + bcopy (p, dirname, dirend - p); + dirname[dirend - p] = '\0'; + dir = find_directory (dirname); + p = dirend + 1; + } + + if (dir->files == 0) + /* There are no files entered for this directory. */ + return 0; + + for (hash = 0; *p != '\0'; ++p) + HASH (hash, *p); + hash %= DIRFILE_BUCKETS; + + for (next = dir->files[hash]; next != 0; next = next->next) + if (streq (filename, next->name)) + return next->impossible; + + return 0; +} + +/* Return the already allocated name in the + directory hash table that matches DIR. */ + +char * +dir_name (dir) + char *dir; +{ + return find_directory (dir)->name; +} + +/* Print the data base of directories. */ + +void +print_dir_data_base () +{ + register unsigned int i, dirs, files, impossible; + register struct directory *dir; + + puts ("\n# Directories\n"); + + dirs = files = impossible = 0; + for (i = 0; i < DIRECTORY_BUCKETS; ++i) + for (dir = directories[i]; dir != 0; dir = dir->next) + { + ++dirs; + if (dir->files == 0) + printf ("# %s: could not be opened.\n", dir->name); + else + { + register unsigned int f = 0, im = 0; + register unsigned int j; + register struct dirfile *df; + for (j = 0; j < DIRFILE_BUCKETS; ++j) + for (df = dir->files[j]; df != 0; df = df->next) + if (df->impossible) + ++im; + else + ++f; + printf ("# %s: ", dir->name); + if (f == 0) + fputs ("No", stdout); + else + printf ("%u", f); + fputs (" files, ", stdout); + if (im == 0) + fputs ("no", stdout); + else + printf ("%u", im); + fputs (" impossibilities", stdout); + if (dir->dirstream == 0) + puts ("."); + else + puts (" so far."); + files += f; + impossible += im; + } + } + + fputs ("\n# ", stdout); + if (files == 0) + fputs ("No", stdout); + else + printf ("%u", files); + fputs (" files, ", stdout); + if (impossible == 0) + fputs ("no", stdout); + else + printf ("%u", impossible); + printf (" impossibilities in %u directories.\n", dirs); +} |