1 files changed, 353 insertions, 0 deletions

diff --git a/tools/perf/util/path.c b/tools/perf/util/path.c
new file mode 100644
index 000000000000..a501a40dd2cb
--- /dev/null
+++ b/tools/perf/util/path.c
@@ -0,0 +1,353 @@
+/*
+ * I'm tired of doing "vsnprintf()" etc just to open a
+ * file, so here's a "return static buffer with printf"
+ * interface for paths.
+ *
+ * It's obviously not thread-safe. Sue me. But it's quite
+ * useful for doing things like
+ *
+ *   f = open(mkpath("%s/%s.perf", base, name), O_RDONLY);
+ *
+ * which is what it's designed for.
+ */
+#include "cache.h"
+
+static char bad_path[] = "/bad-path/";
+/*
+ * Two hacks:
+ */
+
+static char *get_perf_dir(void)
+{
+        return ".";
+}
+
+size_t strlcpy(char *dest, const char *src, size_t size)
+{
+        size_t ret = strlen(src);
+
+        if (size) {
+                size_t len = (ret >= size) ? size - 1 : ret;
+                memcpy(dest, src, len);
+                dest[len] = '\0';
+        }
+        return ret;
+}
+
+
+static char *get_pathname(void)
+{
+        static char pathname_array[4][PATH_MAX];
+        static int index;
+        return pathname_array[3 & ++index];
+}
+
+static char *cleanup_path(char *path)
+{
+        /* Clean it up */
+        if (!memcmp(path, "./", 2)) {
+                path += 2;
+                while (*path == '/')
+                        path++;
+        }
+        return path;
+}
+
+char *mksnpath(char *buf, size_t n, const char *fmt, ...)
+{
+        va_list args;
+        unsigned len;
+
+        va_start(args, fmt);
+        len = vsnprintf(buf, n, fmt, args);
+        va_end(args);
+        if (len >= n) {
+                strlcpy(buf, bad_path, n);
+                return buf;
+        }
+        return cleanup_path(buf);
+}
+
+static char *perf_vsnpath(char *buf, size_t n, const char *fmt, va_list args)
+{
+        const char *perf_dir = get_perf_dir();
+        size_t len;
+
+        len = strlen(perf_dir);
+        if (n < len + 1)
+                goto bad;
+        memcpy(buf, perf_dir, len);
+        if (len && !is_dir_sep(perf_dir[len-1]))
+                buf[len++] = '/';
+        len += vsnprintf(buf + len, n - len, fmt, args);
+        if (len >= n)
+                goto bad;
+        return cleanup_path(buf);
+bad:
+        strlcpy(buf, bad_path, n);
+        return buf;
+}
+
+char *perf_snpath(char *buf, size_t n, const char *fmt, ...)
+{
+        va_list args;
+        va_start(args, fmt);
+        (void)perf_vsnpath(buf, n, fmt, args);
+        va_end(args);
+        return buf;
+}
+
+char *perf_pathdup(const char *fmt, ...)
+{
+        char path[PATH_MAX];
+        va_list args;
+        va_start(args, fmt);
+        (void)perf_vsnpath(path, sizeof(path), fmt, args);
+        va_end(args);
+        return xstrdup(path);
+}
+
+char *mkpath(const char *fmt, ...)
+{
+        va_list args;
+        unsigned len;
+        char *pathname = get_pathname();
+
+        va_start(args, fmt);
+        len = vsnprintf(pathname, PATH_MAX, fmt, args);
+        va_end(args);
+        if (len >= PATH_MAX)
+                return bad_path;
+        return cleanup_path(pathname);
+}
+
+char *perf_path(const char *fmt, ...)
+{
+        const char *perf_dir = get_perf_dir();
+        char *pathname = get_pathname();
+        va_list args;
+        unsigned len;
+
+        len = strlen(perf_dir);
+        if (len > PATH_MAX-100)
+                return bad_path;
+        memcpy(pathname, perf_dir, len);
+        if (len && perf_dir[len-1] != '/')
+                pathname[len++] = '/';
+        va_start(args, fmt);
+        len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
+        va_end(args);
+        if (len >= PATH_MAX)
+                return bad_path;
+        return cleanup_path(pathname);
+}
+
+
+/* perf_mkstemp() - create tmp file honoring TMPDIR variable */
+int perf_mkstemp(char *path, size_t len, const char *template)
+{
+        const char *tmp;
+        size_t n;
+
+        tmp = getenv("TMPDIR");
+        if (!tmp)
+                tmp = "/tmp";
+        n = snprintf(path, len, "%s/%s", tmp, template);
+        if (len <= n) {
+                errno = ENAMETOOLONG;
+                return -1;
+        }
+        return mkstemp(path);
+}
+
+
+const char *make_relative_path(const char *abs, const char *base)
+{
+        static char buf[PATH_MAX + 1];
+        int baselen;
+        if (!base)
+                return abs;
+        baselen = strlen(base);
+        if (prefixcmp(abs, base))
+                return abs;
+        if (abs[baselen] == '/')
+                baselen++;
+        else if (base[baselen - 1] != '/')
+                return abs;
+        strcpy(buf, abs + baselen);
+        return buf;
+}
+
+/*
+ * It is okay if dst == src, but they should not overlap otherwise.
+ *
+ * Performs the following normalizations on src, storing the result in dst:
+ * - Ensures that components are separated by '/' (Windows only)
+ * - Squashes sequences of '/'.
+ * - Removes "." components.
+ * - Removes ".." components, and the components the precede them.
+ * Returns failure (non-zero) if a ".." component appears as first path
+ * component anytime during the normalization. Otherwise, returns success (0).
+ *
+ * Note that this function is purely textual.  It does not follow symlinks,
+ * verify the existence of the path, or make any system calls.
+ */
+int normalize_path_copy(char *dst, const char *src)
+{
+        char *dst0;
+
+        if (has_dos_drive_prefix(src)) {
+                *dst++ = *src++;
+                *dst++ = *src++;
+        }
+        dst0 = dst;
+
+        if (is_dir_sep(*src)) {
+                *dst++ = '/';
+                while (is_dir_sep(*src))
+                        src++;
+        }
+
+        for (;;) {
+                char c = *src;
+
+                /*
+                 * A path component that begins with . could be
+                 * special:
+                 * (1) "." and ends   -- ignore and terminate.
+                 * (2) "./"           -- ignore them, eat slash and continue.
+                 * (3) ".." and ends  -- strip one and terminate.
+                 * (4) "../"          -- strip one, eat slash and continue.
+                 */
+                if (c == '.') {
+                        if (!src[1]) {
+                                /* (1) */
+                                src++;
+                        } else if (is_dir_sep(src[1])) {
+                                /* (2) */
+                                src += 2;
+                                while (is_dir_sep(*src))
+                                        src++;
+                                continue;
+                        } else if (src[1] == '.') {
+                                if (!src[2]) {
+                                        /* (3) */
+                                        src += 2;
+                                        goto up_one;
+                                } else if (is_dir_sep(src[2])) {
+                                        /* (4) */
+                                        src += 3;
+                                        while (is_dir_sep(*src))
+                                                src++;
+                                        goto up_one;
+                                }
+                        }
+                }
+
+                /* copy up to the next '/', and eat all '/' */
+                while ((c = *src++) != '\0' && !is_dir_sep(c))
+                        *dst++ = c;
+                if (is_dir_sep(c)) {
+                        *dst++ = '/';
+                        while (is_dir_sep(c))
+                                c = *src++;
+                        src--;
+                } else if (!c)
+                        break;
+                continue;
+
+        up_one:
+                /*
+                 * dst0..dst is prefix portion, and dst[-1] is '/';
+                 * go up one level.
+                 */
+                dst--;  /* go to trailing '/' */
+                if (dst <= dst0)
+                        return -1;
+                /* Windows: dst[-1] cannot be backslash anymore */
+                while (dst0 < dst && dst[-1] != '/')
+                        dst--;
+        }
+        *dst = '\0';
+        return 0;
+}
+
+/*
+ * path = Canonical absolute path
+ * prefix_list = Colon-separated list of absolute paths
+ *
+ * Determines, for each path in prefix_list, whether the "prefix" really
+ * is an ancestor directory of path.  Returns the length of the longest
+ * ancestor directory, excluding any trailing slashes, or -1 if no prefix
+ * is an ancestor.  (Note that this means 0 is returned if prefix_list is
+ * "/".) "/foo" is not considered an ancestor of "/foobar".  Directories
+ * are not considered to be their own ancestors.  path must be in a
+ * canonical form: empty components, or "." or ".." components are not
+ * allowed.  prefix_list may be null, which is like "".
+ */
+int longest_ancestor_length(const char *path, const char *prefix_list)
+{
+        char buf[PATH_MAX+1];
+        const char *ceil, *colon;
+        int len, max_len = -1;
+
+        if (prefix_list == NULL || !strcmp(path, "/"))
+                return -1;
+
+        for (colon = ceil = prefix_list; *colon; ceil = colon+1) {
+                for (colon = ceil; *colon && *colon != PATH_SEP; colon++);
+                len = colon - ceil;
+                if (len == 0 || len > PATH_MAX || !is_absolute_path(ceil))
+                        continue;
+                strlcpy(buf, ceil, len+1);
+                if (normalize_path_copy(buf, buf) < 0)
+                        continue;
+                len = strlen(buf);
+                if (len > 0 && buf[len-1] == '/')
+                        buf[--len] = '\0';
+
+                if (!strncmp(path, buf, len) &&
+                    path[len] == '/' &&
+                    len > max_len) {
+                        max_len = len;
+                }
+        }
+
+        return max_len;
+}
+
+/* strip arbitrary amount of directory separators at end of path */
+static inline int chomp_trailing_dir_sep(const char *path, int len)
+{
+        while (len && is_dir_sep(path[len - 1]))
+                len--;
+        return len;
+}
+
+/*
+ * If path ends with suffix (complete path components), returns the
+ * part before suffix (sans trailing directory separators).
+ * Otherwise returns NULL.
+ */
+char *strip_path_suffix(const char *path, const char *suffix)
+{
+        int path_len = strlen(path), suffix_len = strlen(suffix);
+
+        while (suffix_len) {
+                if (!path_len)
+                        return NULL;
+
+                if (is_dir_sep(path[path_len - 1])) {
+                        if (!is_dir_sep(suffix[suffix_len - 1]))
+                                return NULL;
+                        path_len = chomp_trailing_dir_sep(path, path_len);
+                        suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
+                }
+                else if (path[--path_len] != suffix[--suffix_len])
+                        return NULL;
+        }
+
+        if (path_len && !is_dir_sep(path[path_len - 1]))
+                return NULL;
+        return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
+}