From: Tim Kientzle Date: Sun, 30 Aug 2009 23:31:25 +0000 (-0400) Subject: New tree.c/tree.h compiles and seems minimally functional on X-Git-Tag: v2.8.0~405 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a095c60ddef97d8a4cb2becf252983a0d6b80c26;p=thirdparty%2Flibarchive.git New tree.c/tree.h compiles and seems minimally functional on both Windows and Posix platforms. More testing is needed, of course. SVN-Revision: 1402 --- diff --git a/tar/tree.c b/tar/tree.c index e06cb5300..eef0d2ae3 100644 --- a/tar/tree.c +++ b/tar/tree.c @@ -18,6 +18,7 @@ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. @@ -42,12 +43,39 @@ * indicating how to get back to the parent (via chdir("..") for a * regular dir or via fchdir(2) for a symlink). */ -#include "bsdtar_platform.h" -__FBSDID("$FreeBSD: src/usr.bin/tar/tree.c,v 1.9 2008/11/27 05:49:52 kientzle Exp $"); +//#include "bsdtar_platform.h" +//__FBSDID("$FreeBSD: src/usr.bin/tar/tree.c,v 1.9 2008/11/27 05:49:52 kientzle Exp $"); + +#if defined(_WIN32) +#define HAVE_SYS_STAT_H 1 +#define HAVE_DIRECT_H 1 +//#define HAVE_DIRENT_H 1 +#define HAVE_ERRNO_H 1 +#define HAVE_FCNTL_H 1 +#define HAVE_STDLIB_H 1 +#define HAVE_STRING_H 1 +//#define HAVE_UNISTD_H 1 +#define HAVE_WINDOWS_H 1 + +#elif defined(__FreeBSD__) +#define HAVE_SYS_STAT_H 1 +//#define HAVE_DIRECT_H 1 +#define HAVE_DIRENT_H 1 +#define HAVE_ERRNO_H 1 +#define HAVE_FCHDIR 1 +#define HAVE_FCNTL_H 1 +#define HAVE_STDLIB_H 1 +#define HAVE_STRING_H 1 +#define HAVE_UNISTD_H 1 +//#define HAVE_WINDOWS_H 1 +#endif #ifdef HAVE_SYS_STAT_H #include #endif +#ifdef HAVE_DIRECT_H +#include +#endif #ifdef HAVE_DIRENT_H #include #endif @@ -66,6 +94,12 @@ __FBSDID("$FreeBSD: src/usr.bin/tar/tree.c,v 1.9 2008/11/27 05:49:52 kientzle Ex #ifdef HAVE_UNISTD_H #include #endif +#ifdef HAVE_WINDOWS_H +#include +#define DIRSEP '\\' +#else +#define DIRSEP '/' +#endif #include "tree.h" @@ -76,27 +110,38 @@ __FBSDID("$FreeBSD: src/usr.bin/tar/tree.c,v 1.9 2008/11/27 05:49:52 kientzle Ex */ struct tree_entry { + int depth; struct tree_entry *next; struct tree_entry *parent; char *name; size_t dirname_length; dev_t dev; ino_t ino; + int flags; + /* How to return back to the parent of a symlink. */ #ifdef HAVE_FCHDIR - int fd; + int symlink_parent_fd; #elif defined(_WIN32) && !defined(__CYGWIN__) - char *fullpath; + char *symlink_parent_path; #else #error fchdir function required. #endif - int flags; }; /* Definitions for tree_entry.flags bitmap. */ #define isDir 1 /* This entry is a regular directory. */ #define isDirLink 2 /* This entry is a symbolic link to a directory. */ -#define needsPreVisit 4 /* This entry needs to be previsited. */ -#define needsPostVisit 8 /* This entry needs to be postvisited. */ +#define needsFirstVisit 4 /* This is an initial entry. */ +#define needsDescent 8 /* This entry needs to be previsited. */ +#define needsOpen 16 /* This is a directory that needs to be opened. */ +#define needsAscent 32 /* This entry needs to be postvisited. */ + +/* + * On Windows, "first visit" is handled as a pattern to be handed to + * _findfirst(). This is consistent with Windows conventions that + * file patterns are handled within the application. On Posix, + * "first visit" is just returned to the client. + */ /* * Local data for this package. @@ -104,21 +149,26 @@ struct tree_entry { struct tree { struct tree_entry *stack; struct tree_entry *current; +#ifdef HAVE_WINDOWS_H + HANDLE d; +#define INVALID_DIR_HANDLE INVALID_HANDLE_VALUE + WIN32_FIND_DATA findData; +#else DIR *d; -#ifdef HAVE_FCHDIR - int initialDirFd; -#elif defined(_WIN32) && !defined(__CYGWIN__) - char *initialDir; +#define INVALID_DIR_HANDLE NULL + struct dirent *de; #endif int flags; int visit_type; int tree_errno; /* Error code from last failed operation. */ + /* Dynamically-sized buffer for holding path */ char *buff; - const char *basename; size_t buff_length; - size_t path_length; - size_t dirname_length; + + const char *basename; /* Last path element */ + size_t dirname_length; /* Leading dir length */ + size_t path_length; /* Total path length */ int depth; int openCount; @@ -129,10 +179,16 @@ struct tree { }; /* Definitions for tree.flags bitmap. */ -#define needsReturn 8 /* Marks first entry as not having been returned yet. */ #define hasStat 16 /* The st entry is set. */ #define hasLstat 32 /* The lst entry is set. */ +#if defined(_WIN32) && !defined(__CYGWIN__) +static int +tree_dir_next_windows(struct tree *t, const char *pattern); +#else +static int +tree_dir_next_posix(struct tree *t); +#endif #ifdef HAVE_DIRENT_D_NAMLEN /* BSD extension; avoids need for a strlen() call. */ @@ -141,25 +197,31 @@ struct tree { #define D_NAMELEN(dp) (strlen((dp)->d_name)) #endif -#if 0 #include void tree_dump(struct tree *t, FILE *out) { + char buff[300]; struct tree_entry *te; fprintf(out, "\tdepth: %d\n", t->depth); fprintf(out, "\tbuff: %s\n", t->buff); - fprintf(out, "\tpwd: "); fflush(stdout); system("pwd"); - fprintf(out, "\taccess: %s\n", t->basename); + fprintf(out, "\tpwd: %s\n", getcwd(buff, sizeof(buff))); + fprintf(out, "\tbasename: %s\n", t->basename); fprintf(out, "\tstack:\n"); for (te = t->stack; te != NULL; te = te->next) { - fprintf(out, "\t\tte->name: %s%s%s\n", te->name, - te->flags & needsPreVisit ? "" : " *", - t->current == te ? " (current)" : ""); + fprintf(out, "\t\t%s%d:\"%s\" %s%s%s%s%s\n", + t->current == te ? "*" : " ", + te->depth, + te->name, + te->flags & needsFirstVisit ? "V" : "", + te->flags & needsDescent ? "D" : "", + te->flags & needsOpen ? "O" : "", + te->flags & needsAscent ? "A" : "", + (t->current == te && t->d) ? "+" : "" + ); } } -#endif /* * Add a directory path to the current stack. @@ -172,19 +234,23 @@ tree_push(struct tree *t, const char *path) te = malloc(sizeof(*te)); memset(te, 0, sizeof(*te)); te->next = t->stack; + te->parent = t->current; + if (te->parent) + te->depth = te->parent->depth + 1; t->stack = te; #ifdef HAVE_FCHDIR - te->fd = -1; + te->symlink_parent_fd = -1; + te->name = strdup(path); #elif defined(_WIN32) && !defined(__CYGWIN__) - te->fullpath = NULL; + te->symlink_parent_path = NULL; + te->name = _strdup(path); #endif - te->name = strdup(path); - te->flags = needsPreVisit | needsPostVisit; + te->flags = needsDescent | needsOpen | needsAscent; te->dirname_length = t->dirname_length; } /* - * Append a name to the current path. + * Append a name to the current dir path. */ static void tree_append(struct tree *t, const char *name, size_t name_length) @@ -194,7 +260,8 @@ tree_append(struct tree *t, const char *name, size_t name_length) if (t->buff != NULL) t->buff[t->dirname_length] = '\0'; /* Strip trailing '/' from name, unless entire name is "/". */ - while (name_length > 1 && name[name_length - 1] == '/') + while (name_length > 1 && + (name[name_length - 1] == '/' || name[name_length - 1] == '/')) name_length--; /* Resize pathname buffer as needed. */ @@ -203,15 +270,21 @@ tree_append(struct tree *t, const char *name, size_t name_length) if (t->buff_length < 1024) t->buff_length = 1024; t->buff = realloc(t->buff, t->buff_length); + if (t->buff == NULL) + abort(); } p = t->buff + t->dirname_length; t->path_length = t->dirname_length + name_length; /* Add a separating '/' if it's needed. */ - if (t->dirname_length > 0 && p[-1] != '/') { - *p++ = '/'; + if (t->dirname_length > 0 && p[-1] != '/' && p[-1] != '\\') { + *p++ = DIRSEP; t->path_length ++; } +#if defined(_WIN32) && !defined(__CYGWIN__) + strncpy_s(p, t->buff_length - (p - t->buff), name, name_length); +#else strncpy(p, name, name_length); +#endif p[name_length] = '\0'; t->basename = p; } @@ -226,19 +299,17 @@ tree_open(const char *path) t = malloc(sizeof(*t)); memset(t, 0, sizeof(*t)); - tree_append(t, path, strlen(path)); +// tree_append(t, path, strlen(path)); + /* First item is set up a lot like a symlink traversal. */ + tree_push(t, path); + t->stack->flags = needsFirstVisit | isDirLink; #ifdef HAVE_FCHDIR - t->initialDirFd = open(".", O_RDONLY); + t->stack->symlink_parent_fd = open(".", O_RDONLY); + t->openCount++; #elif defined(_WIN32) && !defined(__CYGWIN__) - t->initialDir = getcwd(NULL, 0); + t->stack->symlink_parent_path = _getcwd(NULL, 0); #endif - /* - * During most of the traversal, items are set up and then - * returned immediately from tree_next(). That doesn't work - * for the very first entry, so we set a flag for this special - * case. - */ - t->flags = needsReturn; + t->d = INVALID_DIR_HANDLE; return (t); } @@ -255,22 +326,26 @@ tree_ascend(struct tree *t) t->depth--; if (te->flags & isDirLink) { #ifdef HAVE_FCHDIR - if (fchdir(te->fd) != 0) { + if (fchdir(te->symlink_parent_fd) != 0) { t->tree_errno = errno; r = TREE_ERROR_FATAL; } - close(te->fd); + close(te->symlink_parent_fd); #elif defined(_WIN32) && !defined(__CYGWIN__) - if (chdir(te->fullpath) != 0) { + if (SetCurrentDirectory(te->symlink_parent_path) == 0) { t->tree_errno = errno; r = TREE_ERROR_FATAL; } - free(te->fullpath); - te->fullpath = NULL; + free(te->symlink_parent_path); + te->symlink_parent_path = NULL; #endif t->openCount--; } else { +#if defined(_WIN32) && !defined(__CYGWIN__) + if (SetCurrentDirectory("..") == 0) { +#else if (chdir("..") != 0) { +#endif t->tree_errno = errno; r = TREE_ERROR_FATAL; } @@ -286,16 +361,18 @@ tree_pop(struct tree *t) { struct tree_entry *te; - t->buff[t->dirname_length] = '\0'; + if (t->buff) + t->buff[t->dirname_length] = '\0'; if (t->stack == t->current && t->current != NULL) t->current = t->current->parent; te = t->stack; t->stack = te->next; t->dirname_length = te->dirname_length; - t->basename = t->buff + t->dirname_length; - /* Special case: starting dir doesn't skip leading '/'. */ - if (t->dirname_length > 0) - t->basename++; + if (t->buff) { + t->basename = t->buff + t->dirname_length; + while (t->basename[0] == '/' || t->basename[0] == '\\') + t->basename++; + } free(te->name); free(te); } @@ -306,7 +383,6 @@ tree_pop(struct tree *t) int tree_next(struct tree *t) { - struct dirent *de = NULL; int r; /* If we're called again after a fatal error, that's an API @@ -314,92 +390,177 @@ tree_next(struct tree *t) if (t->visit_type == TREE_ERROR_FATAL) { fprintf(stderr, "Unable to continue traversing" " directory heirarchy after a fatal error."); - *(int *)0 = 1; /* Deliberate SEGV; NULL pointer dereference. */ - exit(1); /* In case the SEGV didn't work. */ - } - - /* Handle the startup case by returning the initial entry. */ - if (t->flags & needsReturn) { - t->flags &= ~needsReturn; - return (t->visit_type = TREE_REGULAR); + abort(); } while (t->stack != NULL) { /* If there's an open dir, get the next entry from there. */ - while (t->d != NULL) { - de = readdir(t->d); - if (de == NULL) { - closedir(t->d); - t->d = NULL; - } else if (de->d_name[0] == '.' - && de->d_name[1] == '\0') { - /* Skip '.' */ - } else if (de->d_name[0] == '.' - && de->d_name[1] == '.' - && de->d_name[2] == '\0') { - /* Skip '..' */ - } else { - /* - * Append the path to the current path - * and return it. - */ - tree_append(t, de->d_name, D_NAMELEN(de)); - t->flags &= ~hasLstat; - t->flags &= ~hasStat; - return (t->visit_type = TREE_REGULAR); - } + if (t->d != INVALID_DIR_HANDLE) { +#if defined(_WIN32) && !defined(__CYGWIN__) + r = tree_dir_next_windows(t, NULL); +#else + r = tree_dir_next_posix(t); +#endif + if (r == 0) + continue; + return (r); } - /* If the current dir needs to be visited, set it up. */ - if (t->stack->flags & needsPreVisit) { + if (t->stack->flags & needsFirstVisit) { +#if defined(_WIN32) && !defined(__CYGWIN__) + char *d = strdup(t->stack->name); + char *p, *pattern; + tree_pop(t); + if ((p = strrchr(d, '\\')) != NULL) { + pattern = strdup(p + 1); + p[1] = '\0'; + chdir(d); + tree_append(t, d, strlen(d)); + } else { + abort(); + } + r = tree_dir_next_windows(t, pattern); + free(pattern); + if (r == 0) + continue; + return (r); +#else + /* Top stack item needs a regular visit. */ t->current = t->stack; tree_append(t, t->stack->name, strlen(t->stack->name)); - t->stack->flags &= ~needsPreVisit; + t->dirname_length = t->path_length; + tree_pop(t); + return (t->visit_type = TREE_REGULAR); +#endif + } else if (t->stack->flags & needsDescent) { + /* Top stack item is dir to descend into. */ + t->current = t->stack; + tree_append(t, t->stack->name, strlen(t->stack->name)); + t->stack->flags &= ~needsDescent; /* If it is a link, set up fd for the ascent. */ if (t->stack->flags & isDirLink) { #ifdef HAVE_FCHDIR - t->stack->fd = open(".", O_RDONLY); -#elif defined(_WIN32) && !defined(__CYGWIN__) - t->stack->fullpath = getcwd(NULL, 0); -#endif + t->stack->symlink_parent_fd = open(".", O_RDONLY); t->openCount++; if (t->openCount > t->maxOpenCount) t->maxOpenCount = t->openCount; +#elif defined(_WIN32) && !defined(__CYGWIN__) + t->stack->symlink_parent_path = _getcwd(NULL, 0); +#endif } t->dirname_length = t->path_length; - if (chdir(t->stack->name) != 0) { +#if defined(_WIN32) && !defined(__CYGWIN__) + if (t->path_length == 259 || !SetCurrentDirectory(t->stack->name) != 0) +#else + if (chdir(t->stack->name) != 0) +#endif + { /* chdir() failed; return error */ tree_pop(t); t->tree_errno = errno; return (t->visit_type = TREE_ERROR_DIR); } t->depth++; - t->d = opendir("."); - if (t->d == NULL) { + return (t->visit_type = TREE_POSTDESCENT); + } else if (t->stack->flags & needsOpen) { + t->stack->flags &= ~needsOpen; +#if defined(_WIN32) && !defined(__CYGWIN__) + r = tree_dir_next_windows(t, "*"); +#else + r = tree_dir_next_posix(t); +#endif + if (r == 0) + continue; + return (r); + } else if (t->stack->flags & needsAscent) { + /* Top stack item is dir and we're done with it. */ + r = tree_ascend(t); + tree_pop(t); + t->visit_type = r != 0 ? r : TREE_POSTASCENT; + return (t->visit_type); + } else { + /* Top item on stack is dead. */ + tree_pop(t); + t->flags &= ~hasLstat; + t->flags &= ~hasStat; + } + } + return (t->visit_type = 0); +} + +#if defined(_WIN32) && !defined(__CYGWIN__) +static int +tree_dir_next_windows(struct tree *t, const char *pattern) +{ + const char *name; + size_t namelen; + int r; + + for (;;) { + if (pattern != NULL) { + t->d = FindFirstFile(pattern, &t->findData); + if (t->d == INVALID_DIR_HANDLE) { r = tree_ascend(t); /* Undo "chdir" */ tree_pop(t); t->tree_errno = errno; t->visit_type = r != 0 ? r : TREE_ERROR_DIR; return (t->visit_type); } - t->flags &= ~hasLstat; - t->flags &= ~hasStat; - t->basename = "."; - return (t->visit_type = TREE_POSTDESCENT); + pattern = NULL; + } else if (!FindNextFile(t->d, &t->findData)) { + FindClose(t->d); + t->d = INVALID_DIR_HANDLE; + return (0); } + name = t->findData.cFileName; + namelen = strlen(name); + t->flags &= ~hasLstat; + t->flags &= ~hasStat; + if (name[0] == '.' && name[1] == '\0') + continue; + if (name[0] == '.' && name[1] == '.' && name[2] == '\0') + continue; + tree_append(t, name, namelen); + return (t->visit_type = TREE_REGULAR); + } +} +#else +static int +tree_dir_next_posix(struct tree *t) +{ + int r; + const char *name; + size_t namelen; - /* We've done everything necessary for the top stack entry. */ - if (t->stack->flags & needsPostVisit) { - r = tree_ascend(t); + if (t->d == NULL) { + if ((t->d = opendir(".")) == NULL) { + r = tree_ascend(t); /* Undo "chdir" */ tree_pop(t); - t->flags &= ~hasLstat; - t->flags &= ~hasStat; - t->visit_type = r != 0 ? r : TREE_POSTASCENT; + t->tree_errno = errno; + t->visit_type = r != 0 ? r : TREE_ERROR_DIR; return (t->visit_type); } } - return (t->visit_type = 0); + for (;;) { + t->de = readdir(t->d); + if (t->de == NULL) { + closedir(t->d); + t->d = INVALID_DIR_HANDLE; + return (0); + } + name = t->de->d_name; + namelen = D_NAMELEN(t->de); + t->flags &= ~hasLstat; + t->flags &= ~hasStat; + if (name[0] == '.' && name[1] == '\0') + continue; + if (name[0] == '.' && name[1] == '.' && name[2] == '\0') + continue; + tree_append(t, name, namelen); + return (t->visit_type = TREE_REGULAR); + } } +#endif /* * Return error code. @@ -436,7 +597,7 @@ const struct stat * tree_current_stat(struct tree *t) { if (!(t->flags & hasStat)) { - if (stat(t->basename, &t->st) != 0) + if (stat(tree_current_access_path(t), &t->st) != 0) return NULL; t->flags |= hasStat; } @@ -449,12 +610,16 @@ tree_current_stat(struct tree *t) const struct stat * tree_current_lstat(struct tree *t) { +#if defined(_WIN32) + return (tree_current_stat(t)); +#else if (!(t->flags & hasLstat)) { - if (lstat(t->basename, &t->lst) != 0) + if (lstat(tree_current_access_path(t), &t->lst) != 0) return NULL; t->flags |= hasLstat; } return (&t->lst); +#endif } /* @@ -463,8 +628,10 @@ tree_current_lstat(struct tree *t) int tree_current_is_dir(struct tree *t) { +#if defined(_WIN32) + return (t->findData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY); +#else const struct stat *st; - /* * If we already have lstat() info, then try some * cheap tests to determine if this is a dir. @@ -489,6 +656,7 @@ tree_current_is_dir(struct tree *t) return 0; /* Use the definitive test. Hopefully this is cached. */ return (S_ISDIR(st->st_mode)); +#endif } /* @@ -499,6 +667,11 @@ tree_current_is_dir(struct tree *t) int tree_current_is_physical_dir(struct tree *t) { +#if defined(_WIN32) + if (tree_current_is_physical_link(t)) + return (0); + return (tree_current_is_dir(t)); +#else const struct stat *st; /* @@ -522,6 +695,7 @@ tree_current_is_physical_dir(struct tree *t) return 0; /* Use the definitive test. Hopefully this is cached. */ return (S_ISDIR(st->st_mode)); +#endif } /* @@ -530,10 +704,15 @@ tree_current_is_physical_dir(struct tree *t) int tree_current_is_physical_link(struct tree *t) { +#if defined(_WIN32) + return ((t->findData.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) + && (t->findData.dwReserved0 == IO_REPARSE_TAG_SYMLINK)); +#else const struct stat *st = tree_current_lstat(t); if (st == NULL) return 0; return (S_ISLNK(st->st_mode)); +#endif } /* @@ -583,7 +762,8 @@ tree_close(struct tree *t) tree_pop(t); if (t->buff) free(t->buff); - /* chdir() back to where we started. */ + /* TODO: Ensure that premature close() resets cwd */ +#if 0 #ifdef HAVE_FCHDIR if (t->initialDirFd >= 0) { int s = fchdir(t->initialDirFd); @@ -593,10 +773,11 @@ tree_close(struct tree *t) } #elif defined(_WIN32) && !defined(__CYGWIN__) if (t->initialDir != NULL) { - chdir(t->initialDir); + SetCurrentDir(t->initialDir); free(t->initialDir); t->initialDir = NULL; } +#endif #endif free(t); } diff --git a/tar/tree.h b/tar/tree.h index 30d96fe3b..9a7e0d307 100644 --- a/tar/tree.h +++ b/tar/tree.h @@ -53,16 +53,17 @@ void tree_close(struct tree *); /* * tree_next() returns Zero if there is no next entry, non-zero if - * there is. Note that directories are potentially visited three - * times. Directories are always visited first as part of enumerating - * their parent. If tree_descend() is invoked at that time, the - * directory is added to a work list and will subsequently be visited - * two more times: once just after descending into the directory and - * again just after ascending back to the parent. + * there is. Note that directories are visited three times. + * Directories are always visited first as part of enumerating their + * parent; that is a "regular" visit. If tree_descend() is invoked at + * that time, the directory is added to a work list and will + * subsequently be visited two more times: once just after descending + * into the directory ("postdescent") and again just after ascending + * back to the parent ("postascent"). * * TREE_ERROR_DIR is returned if the descent failed (because the * directory couldn't be opened, for instance). This is returned - * instead of TREE_PREVISIT/TREE_POSTVISIT. TREE_ERROR_DIR is not a + * instead of TREE_POSTDESCENT/TREE_POSTASCENT. TREE_ERROR_DIR is not a * fatal error, but it does imply that the relevant subtree won't be * visited. TREE_ERROR_FATAL is returned for an error that left the * traversal completely hosed. Right now, this is only returned for @@ -96,10 +97,23 @@ void tree_descend(struct tree *); int tree_current_depth(struct tree *); /* - * The current full pathname, length of the full pathname, - * and a name that can be used to access the file. - * Because tree does use chdir extensively, the access path is - * almost never the same as the full current path. + * The current full pathname, length of the full pathname, and a name + * that can be used to access the file. Because tree does use chdir + * extensively, the access path is almost never the same as the full + * current path. + * + * TODO: Flesh out this interface to provide other information. In + * particular, Windows can provide file size, mode, and some permission + * information without invoking stat() at all. + * + * TODO: On platforms that support it, use openat()-style operations + * to eliminate the chdir() operations entirely while still supporting + * arbitrarily deep traversals. This makes access_path troublesome to + * support, of course, which means we'll need a rich enough interface + * that clients can function without it. (In particular, we'll need + * tree_current_open() that returns an open file descriptor.) + * + * TODO: Provide tree_current_archive_entry(). */ const char *tree_current_path(struct tree *); size_t tree_current_pathlen(struct tree *);