git/pathspec.c
Stefan Beller 2d81c48fa7 pathspec: give better message for submodule related pathspec error
Every once in a while someone complains to the mailing list to have
run into this weird assertion[1]. The usual response from the mailing
list is link to old discussions[2], and acknowledging the problem
stating it is known.

This patch accomplishes two things:

  1. Switch assert() to die("BUG") to give a more readable message.

  2. Take one of the cases where we hit a BUG and turn it into a normal
     "there was something wrong with the input" message.

     This assertion triggered for cases where there wasn't a programming
     bug, but just bogus input. In particular, if the user asks for a
     pathspec that is inside a submodule, we shouldn't assert() or
     die("BUG"); we should tell the user their request is bogus.

     The only reason we did not check for it, is the expensive nature
     of such a check, so callers avoid setting the flag
     PATHSPEC_STRIP_SUBMODULE_SLASH_EXPENSIVE. However when we die due
     to bogus input, the expense of CPU cycles spent outweighs the user
     wondering what went wrong, so run that check unconditionally before
     dying with a more generic error message.

Note: There is a case (e.g. "git -C submodule add .") in which we call
strip_submodule_slash_expensive, as git-add requests it via the flag
PATHSPEC_STRIP_SUBMODULE_SLASH_EXPENSIVE, but the assert used to
trigger nevertheless, because the flag PATHSPEC_LITERAL was not set,
such that we executed

	if (item->nowildcard_len < prefixlen)
		item->nowildcard_len = prefixlen;

and prefixlen was not adapted (e.g. it was computed from "submodule/")
So in the die_inside_submodule_path function we also need handle paths,
that were stripped before, i.e. are the exact submodule path. This
is why the conditions in die_inside_submodule_path are slightly
different than in strip_submodule_slash_expensive.

[1] https://www.google.com/search?q=item-%3Enowildcard_len
[2] http://git.661346.n2.nabble.com/assert-failed-in-submodule-edge-case-td7628687.html
    https://www.spinics.net/lists/git/msg249473.html

Helped-by: Jeff King <peff@peff.net>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-09 15:19:22 -08:00

581 lines
15 KiB
C

#include "cache.h"
#include "dir.h"
#include "pathspec.h"
/*
* Finds which of the given pathspecs match items in the index.
*
* For each pathspec, sets the corresponding entry in the seen[] array
* (which should be specs items long, i.e. the same size as pathspec)
* to the nature of the "closest" (i.e. most specific) match found for
* that pathspec in the index, if it was a closer type of match than
* the existing entry. As an optimization, matching is skipped
* altogether if seen[] already only contains non-zero entries.
*
* If seen[] has not already been written to, it may make sense
* to use find_pathspecs_matching_against_index() instead.
*/
void add_pathspec_matches_against_index(const struct pathspec *pathspec,
char *seen)
{
int num_unmatched = 0, i;
/*
* Since we are walking the index as if we were walking the directory,
* we have to mark the matched pathspec as seen; otherwise we will
* mistakenly think that the user gave a pathspec that did not match
* anything.
*/
for (i = 0; i < pathspec->nr; i++)
if (!seen[i])
num_unmatched++;
if (!num_unmatched)
return;
for (i = 0; i < active_nr; i++) {
const struct cache_entry *ce = active_cache[i];
ce_path_match(ce, pathspec, seen);
}
}
/*
* Finds which of the given pathspecs match items in the index.
*
* This is a one-shot wrapper around add_pathspec_matches_against_index()
* which allocates, populates, and returns a seen[] array indicating the
* nature of the "closest" (i.e. most specific) matches which each of the
* given pathspecs achieves against all items in the index.
*/
char *find_pathspecs_matching_against_index(const struct pathspec *pathspec)
{
char *seen = xcalloc(pathspec->nr, 1);
add_pathspec_matches_against_index(pathspec, seen);
return seen;
}
/*
* Magic pathspec
*
* Possible future magic semantics include stuff like:
*
* { PATHSPEC_RECURSIVE, '*', "recursive" },
* { PATHSPEC_REGEXP, '\0', "regexp" },
*
*/
static struct pathspec_magic {
unsigned bit;
char mnemonic; /* this cannot be ':'! */
const char *name;
} pathspec_magic[] = {
{ PATHSPEC_FROMTOP, '/', "top" },
{ PATHSPEC_LITERAL, '\0', "literal" },
{ PATHSPEC_GLOB, '\0', "glob" },
{ PATHSPEC_ICASE, '\0', "icase" },
{ PATHSPEC_EXCLUDE, '!', "exclude" },
};
static void prefix_magic(struct strbuf *sb, int prefixlen, unsigned magic)
{
int i;
strbuf_addstr(sb, ":(");
for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
if (magic & pathspec_magic[i].bit) {
if (sb->buf[sb->len - 1] != '(')
strbuf_addch(sb, ',');
strbuf_addstr(sb, pathspec_magic[i].name);
}
strbuf_addf(sb, ",prefix:%d)", prefixlen);
}
static inline int get_literal_global(void)
{
static int literal = -1;
if (literal < 0)
literal = git_env_bool(GIT_LITERAL_PATHSPECS_ENVIRONMENT, 0);
return literal;
}
static inline int get_glob_global(void)
{
static int glob = -1;
if (glob < 0)
glob = git_env_bool(GIT_GLOB_PATHSPECS_ENVIRONMENT, 0);
return glob;
}
static inline int get_noglob_global(void)
{
static int noglob = -1;
if (noglob < 0)
noglob = git_env_bool(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, 0);
return noglob;
}
static inline int get_icase_global(void)
{
static int icase = -1;
if (icase < 0)
icase = git_env_bool(GIT_ICASE_PATHSPECS_ENVIRONMENT, 0);
return icase;
}
static int get_global_magic(int element_magic)
{
int global_magic = 0;
if (get_literal_global())
global_magic |= PATHSPEC_LITERAL;
/* --glob-pathspec is overridden by :(literal) */
if (get_glob_global() && !(element_magic & PATHSPEC_LITERAL))
global_magic |= PATHSPEC_GLOB;
if (get_glob_global() && get_noglob_global())
die(_("global 'glob' and 'noglob' pathspec settings are incompatible"));
if (get_icase_global())
global_magic |= PATHSPEC_ICASE;
if ((global_magic & PATHSPEC_LITERAL) &&
(global_magic & ~PATHSPEC_LITERAL))
die(_("global 'literal' pathspec setting is incompatible "
"with all other global pathspec settings"));
/* --noglob-pathspec adds :(literal) _unless_ :(glob) is specified */
if (get_noglob_global() && !(element_magic & PATHSPEC_GLOB))
global_magic |= PATHSPEC_LITERAL;
return global_magic;
}
/*
* Parse the pathspec element looking for long magic
*
* saves all magic in 'magic'
* if prefix magic is used, save the prefix length in 'prefix_len'
* returns the position in 'elem' after all magic has been parsed
*/
static const char *parse_long_magic(unsigned *magic, int *prefix_len,
const char *elem)
{
const char *pos;
const char *nextat;
for (pos = elem + 2; *pos && *pos != ')'; pos = nextat) {
size_t len = strcspn(pos, ",)");
int i;
if (pos[len] == ',')
nextat = pos + len + 1; /* handle ',' */
else
nextat = pos + len; /* handle ')' and '\0' */
if (!len)
continue;
if (starts_with(pos, "prefix:")) {
char *endptr;
*prefix_len = strtol(pos + 7, &endptr, 10);
if (endptr - pos != len)
die(_("invalid parameter for pathspec magic 'prefix'"));
continue;
}
for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
if (strlen(pathspec_magic[i].name) == len &&
!strncmp(pathspec_magic[i].name, pos, len)) {
*magic |= pathspec_magic[i].bit;
break;
}
}
if (ARRAY_SIZE(pathspec_magic) <= i)
die(_("Invalid pathspec magic '%.*s' in '%s'"),
(int) len, pos, elem);
}
if (*pos != ')')
die(_("Missing ')' at the end of pathspec magic in '%s'"),
elem);
pos++;
return pos;
}
/*
* Parse the pathspec element looking for short magic
*
* saves all magic in 'magic'
* returns the position in 'elem' after all magic has been parsed
*/
static const char *parse_short_magic(unsigned *magic, const char *elem)
{
const char *pos;
for (pos = elem + 1; *pos && *pos != ':'; pos++) {
char ch = *pos;
int i;
if (!is_pathspec_magic(ch))
break;
for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
if (pathspec_magic[i].mnemonic == ch) {
*magic |= pathspec_magic[i].bit;
break;
}
}
if (ARRAY_SIZE(pathspec_magic) <= i)
die(_("Unimplemented pathspec magic '%c' in '%s'"),
ch, elem);
}
if (*pos == ':')
pos++;
return pos;
}
static const char *parse_element_magic(unsigned *magic, int *prefix_len,
const char *elem)
{
if (elem[0] != ':' || get_literal_global())
return elem; /* nothing to do */
else if (elem[1] == '(')
/* longhand */
return parse_long_magic(magic, prefix_len, elem);
else
/* shorthand */
return parse_short_magic(magic, elem);
}
static void strip_submodule_slash_cheap(struct pathspec_item *item)
{
if (item->len >= 1 && item->match[item->len - 1] == '/') {
int i = cache_name_pos(item->match, item->len - 1);
if (i >= 0 && S_ISGITLINK(active_cache[i]->ce_mode)) {
item->len--;
item->match[item->len] = '\0';
}
}
}
static void strip_submodule_slash_expensive(struct pathspec_item *item)
{
int i;
for (i = 0; i < active_nr; i++) {
struct cache_entry *ce = active_cache[i];
int ce_len = ce_namelen(ce);
if (!S_ISGITLINK(ce->ce_mode))
continue;
if (item->len <= ce_len || item->match[ce_len] != '/' ||
memcmp(ce->name, item->match, ce_len))
continue;
if (item->len == ce_len + 1) {
/* strip trailing slash */
item->len--;
item->match[item->len] = '\0';
} else {
die(_("Pathspec '%s' is in submodule '%.*s'"),
item->original, ce_len, ce->name);
}
}
}
static void die_inside_submodule_path(struct pathspec_item *item)
{
int i;
for (i = 0; i < active_nr; i++) {
struct cache_entry *ce = active_cache[i];
int ce_len = ce_namelen(ce);
if (!S_ISGITLINK(ce->ce_mode))
continue;
if (item->len < ce_len ||
!(item->match[ce_len] == '/' || item->match[ce_len] == '\0') ||
memcmp(ce->name, item->match, ce_len))
continue;
die(_("Pathspec '%s' is in submodule '%.*s'"),
item->original, ce_len, ce->name);
}
}
/*
* Perform the initialization of a pathspec_item based on a pathspec element.
*/
static void init_pathspec_item(struct pathspec_item *item, unsigned flags,
const char *prefix, int prefixlen,
const char *elt)
{
unsigned magic = 0, element_magic = 0;
const char *copyfrom = elt;
char *match;
int pathspec_prefix = -1;
/* PATHSPEC_LITERAL_PATH ignores magic */
if (flags & PATHSPEC_LITERAL_PATH) {
magic = PATHSPEC_LITERAL;
} else {
copyfrom = parse_element_magic(&element_magic,
&pathspec_prefix,
elt);
magic |= element_magic;
magic |= get_global_magic(element_magic);
}
item->magic = magic;
if (pathspec_prefix >= 0 &&
(prefixlen || (prefix && *prefix)))
die("BUG: 'prefix' magic is supposed to be used at worktree's root");
if ((magic & PATHSPEC_LITERAL) && (magic & PATHSPEC_GLOB))
die(_("%s: 'literal' and 'glob' are incompatible"), elt);
/* Create match string which will be used for pathspec matching */
if (pathspec_prefix >= 0) {
match = xstrdup(copyfrom);
prefixlen = pathspec_prefix;
} else if (magic & PATHSPEC_FROMTOP) {
match = xstrdup(copyfrom);
prefixlen = 0;
} else {
match = prefix_path_gently(prefix, prefixlen,
&prefixlen, copyfrom);
if (!match)
die(_("%s: '%s' is outside repository"), elt, copyfrom);
}
item->match = match;
item->len = strlen(item->match);
item->prefix = prefixlen;
/*
* Prefix the pathspec (keep all magic) and assign to
* original. Useful for passing to another command.
*/
if ((flags & PATHSPEC_PREFIX_ORIGIN) &&
prefixlen && !get_literal_global()) {
struct strbuf sb = STRBUF_INIT;
/* Preserve the actual prefix length of each pattern */
prefix_magic(&sb, prefixlen, element_magic);
strbuf_addstr(&sb, match);
item->original = strbuf_detach(&sb, NULL);
} else {
item->original = xstrdup(elt);
}
if (flags & PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP)
strip_submodule_slash_cheap(item);
if (flags & PATHSPEC_STRIP_SUBMODULE_SLASH_EXPENSIVE)
strip_submodule_slash_expensive(item);
if (magic & PATHSPEC_LITERAL) {
item->nowildcard_len = item->len;
} else {
item->nowildcard_len = simple_length(item->match);
if (item->nowildcard_len < prefixlen)
item->nowildcard_len = prefixlen;
}
item->flags = 0;
if (magic & PATHSPEC_GLOB) {
/*
* FIXME: should we enable ONESTAR in _GLOB for
* pattern "* * / * . c"?
*/
} else {
if (item->nowildcard_len < item->len &&
item->match[item->nowildcard_len] == '*' &&
no_wildcard(item->match + item->nowildcard_len + 1))
item->flags |= PATHSPEC_ONESTAR;
}
/* sanity checks, pathspec matchers assume these are sane */
if (item->nowildcard_len > item->len ||
item->prefix > item->len) {
/*
* This case can be triggered by the user pointing us to a
* pathspec inside a submodule, which is an input error.
* Detect that here and complain, but fallback in the
* non-submodule case to a BUG, as we have no idea what
* would trigger that.
*/
die_inside_submodule_path(item);
die ("BUG: item->nowildcard_len > item->len || item->prefix > item->len)");
}
}
static int pathspec_item_cmp(const void *a_, const void *b_)
{
struct pathspec_item *a, *b;
a = (struct pathspec_item *)a_;
b = (struct pathspec_item *)b_;
return strcmp(a->match, b->match);
}
static void NORETURN unsupported_magic(const char *pattern,
unsigned magic)
{
struct strbuf sb = STRBUF_INIT;
int i;
for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
const struct pathspec_magic *m = pathspec_magic + i;
if (!(magic & m->bit))
continue;
if (sb.len)
strbuf_addstr(&sb, ", ");
if (m->mnemonic)
strbuf_addf(&sb, _("'%s' (mnemonic: '%c')"),
m->name, m->mnemonic);
else
strbuf_addf(&sb, "'%s'", m->name);
}
/*
* We may want to substitute "this command" with a command
* name. E.g. when add--interactive dies when running
* "checkout -p"
*/
die(_("%s: pathspec magic not supported by this command: %s"),
pattern, sb.buf);
}
/*
* Given command line arguments and a prefix, convert the input to
* pathspec. die() if any magic in magic_mask is used.
*/
void parse_pathspec(struct pathspec *pathspec,
unsigned magic_mask, unsigned flags,
const char *prefix, const char **argv)
{
struct pathspec_item *item;
const char *entry = argv ? *argv : NULL;
int i, n, prefixlen, warn_empty_string, nr_exclude = 0;
memset(pathspec, 0, sizeof(*pathspec));
if (flags & PATHSPEC_MAXDEPTH_VALID)
pathspec->magic |= PATHSPEC_MAXDEPTH;
/* No arguments, no prefix -> no pathspec */
if (!entry && !prefix)
return;
if ((flags & PATHSPEC_PREFER_CWD) &&
(flags & PATHSPEC_PREFER_FULL))
die("BUG: PATHSPEC_PREFER_CWD and PATHSPEC_PREFER_FULL are incompatible");
/* No arguments with prefix -> prefix pathspec */
if (!entry) {
if (flags & PATHSPEC_PREFER_FULL)
return;
if (!(flags & PATHSPEC_PREFER_CWD))
die("BUG: PATHSPEC_PREFER_CWD requires arguments");
pathspec->items = item = xcalloc(1, sizeof(*item));
item->match = xstrdup(prefix);
item->original = xstrdup(prefix);
item->nowildcard_len = item->len = strlen(prefix);
item->prefix = item->len;
pathspec->nr = 1;
return;
}
n = 0;
warn_empty_string = 1;
while (argv[n]) {
if (*argv[n] == '\0' && warn_empty_string) {
warning(_("empty strings as pathspecs will be made invalid in upcoming releases. "
"please use . instead if you meant to match all paths"));
warn_empty_string = 0;
}
n++;
}
pathspec->nr = n;
ALLOC_ARRAY(pathspec->items, n);
item = pathspec->items;
prefixlen = prefix ? strlen(prefix) : 0;
for (i = 0; i < n; i++) {
entry = argv[i];
init_pathspec_item(item + i, flags, prefix, prefixlen, entry);
if (item[i].magic & PATHSPEC_EXCLUDE)
nr_exclude++;
if (item[i].magic & magic_mask)
unsupported_magic(entry, item[i].magic & magic_mask);
if ((flags & PATHSPEC_SYMLINK_LEADING_PATH) &&
has_symlink_leading_path(item[i].match, item[i].len)) {
die(_("pathspec '%s' is beyond a symbolic link"), entry);
}
if (item[i].nowildcard_len < item[i].len)
pathspec->has_wildcard = 1;
pathspec->magic |= item[i].magic;
}
if (nr_exclude == n)
die(_("There is nothing to exclude from by :(exclude) patterns.\n"
"Perhaps you forgot to add either ':/' or '.' ?"));
if (pathspec->magic & PATHSPEC_MAXDEPTH) {
if (flags & PATHSPEC_KEEP_ORDER)
die("BUG: PATHSPEC_MAXDEPTH_VALID and PATHSPEC_KEEP_ORDER are incompatible");
QSORT(pathspec->items, pathspec->nr, pathspec_item_cmp);
}
}
void copy_pathspec(struct pathspec *dst, const struct pathspec *src)
{
int i;
*dst = *src;
ALLOC_ARRAY(dst->items, dst->nr);
COPY_ARRAY(dst->items, src->items, dst->nr);
for (i = 0; i < dst->nr; i++) {
dst->items[i].match = xstrdup(src->items[i].match);
dst->items[i].original = xstrdup(src->items[i].original);
}
}
void clear_pathspec(struct pathspec *pathspec)
{
int i;
for (i = 0; i < pathspec->nr; i++) {
free(pathspec->items[i].match);
free(pathspec->items[i].original);
}
free(pathspec->items);
pathspec->items = NULL;
pathspec->nr = 0;
}