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[PATCH v2 13/46] Guard against new pathspec magic in pathspec matching code

From
Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Date
Jul 14, 2013, 08:35 UTC
Message-ID
<1373790969-13000-14-git-send-email-pclouds@gmail.com>
In-Reply-To
<1373790969-13000-1-git-send-email-pclouds@gmail.com>

GUARD_PATHSPEC() marks pathspec-sensitive code, basically all those that touch anything in 'struct pathspec' except fields "nr" and "original". GUARD_PATHSPEC() is not supposed to fail. It's mainly to help the designers catch unsupported codepaths.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Documentation/technical/api-setup.txt | 19 +++++++++++++++++++
 builtin/diff.c                        |  2 ++
 dir.c                                 |  2 ++
 pathspec.h                            |  7 +++++++
 tree-diff.c                           | 19 +++++++++++++++++++
 tree-walk.c                           |  2 ++
 6 files changed, 51 insertions(+)
diff --git a/Documentation/technical/api-setup.txt b/Documentation/technical/api-setup.txt
index 90d1aff..540e455 100644
--- a/Documentation/technical/api-setup.txt
+++ b/Documentation/technical/api-setup.txt
@@ -28,3 +28,22 @@ parse_pathspec(). This function takes several arguments:
 - prefix and args come from cmd_* functions
 
 get_pathspec() is obsolete and should never be used in new code.
+
+parse_pathspec() helps catch unsupported features and reject them
+politely. At a lower level, different pathspec-related functions may
+not support the same set of features. Such pathspec-sensitive
+functions are guarded with GUARD_PATHSPEC(), which will die in an
+unfriendly way when an unsupported feature is requested.
+
+The command designers are supposed to make sure that GUARD_PATHSPEC()
+never dies. They have to make sure all unsupported features are caught
+by parse_pathspec(), not by GUARD_PATHSPEC. grepping GUARD_PATHSPEC()
+should give the designers all pathspec-sensitive codepaths and what
+features they support.
+
+A similar process is applied when a new pathspec magic is added. The
+designer lifts the GUARD_PATHSPEC restriction in the functions that
+support the new magic. At the same time (s)he has to make sure this
+new feature will be caught at parse_pathspec() in commands that cannot
+handle the new magic in some cases. grepping parse_pathspec() should
+help.
diff --git a/builtin/diff.c b/builtin/diff.c
index 9fc273d..6bb41af 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -367,6 +367,8 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 		}
 	}
 	if (rev.prune_data.nr) {
+		/* builtin_diff_b_f() */
+		GUARD_PATHSPEC(&rev.prune_data, PATHSPEC_FROMTOP);
 		if (!path)
 			path = rev.prune_data.items[0].match;
 		paths += rev.prune_data.nr;
diff --git a/dir.c b/dir.c
index e28bc0d..19978d3 100644
--- a/dir.c
+++ b/dir.c
@@ -340,6 +340,8 @@ int match_pathspec_depth(const struct pathspec *ps,
 {
 	int i, retval = 0;
 
+	GUARD_PATHSPEC(ps, PATHSPEC_FROMTOP | PATHSPEC_MAXDEPTH);
+
 	if (!ps->nr) {
 		if (!ps->recursive ||
 		    !(ps->magic & PATHSPEC_MAXDEPTH) ||
diff --git a/pathspec.h b/pathspec.h
index 2e427d7..6baf205 100644
--- a/pathspec.h
+++ b/pathspec.h
@@ -27,6 +27,13 @@ struct pathspec {
 	} *items;
 };
 
+#define GUARD_PATHSPEC(ps, mask) \
+	do { \
+		if ((ps)->magic & ~(mask))	       \
+			die("BUG:%s:%d: unsupported magic %x",	\
+			    __FILE__, __LINE__, (ps)->magic & ~(mask)); \
+	} while (0)
+
 /* parse_pathspec flags */
 #define PATHSPEC_PREFER_CWD (1<<0) /* No args means match cwd */
 #define PATHSPEC_PREFER_FULL (1<<1) /* No args means match everything */
diff --git a/tree-diff.c b/tree-diff.c
index 826512e..5a87614 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -198,6 +198,25 @@ static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, co
 	const char *paths[1];
 	int i;
 
+	/*
+	 * follow-rename code is very specific, we need exactly one
+	 * path. Magic that matches more than one path is not
+	 * supported.
+	 */
+	GUARD_PATHSPEC(&opt->pathspec, PATHSPEC_FROMTOP);
+#if 0
+	/*
+	 * We should reject wildcards as well. Unfortunately we
+	 * haven't got a reliable way to detect that 'foo\*bar' in
+	 * fact has no wildcards. nowildcard_len is merely a hint for
+	 * optimization. Let it slip for now until wildmatch is taught
+	 * about dry-run mode and returns wildcard info.
+	 */
+	if (opt->pathspec.has_wildcard)
+		die("BUG:%s:%d: wildcards are not supported",
+		    __FILE__, __LINE__);
+#endif
+
 	/* Remove the file creation entry from the diff queue, and remember it */
 	choice = q->queue[0];
 	q->nr = 0;
diff --git a/tree-walk.c b/tree-walk.c
index d399ca9..37b157e 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -636,6 +636,8 @@ enum interesting tree_entry_interesting(const struct name_entry *entry,
 	enum interesting never_interesting = ps->has_wildcard ?
 		entry_not_interesting : all_entries_not_interesting;
 
+	GUARD_PATHSPEC(ps, PATHSPEC_FROMTOP | PATHSPEC_MAXDEPTH);
+
 	if (!ps->nr) {
 		if (!ps->recursive ||
 		    !(ps->magic & PATHSPEC_MAXDEPTH) ||

-- 
1.8.2.83.gc99314b
Previous: Nguyễn Thái Ngọc DuyNext: Nguyễn Thái Ngọc Duy
Message 14 of 52 in “"struct pathspec" conversion and :(glob) and :(icase)”
  1. 00/46 "struct pathspec" conversion and :(glob) and :(icase)Nguyễn Thái Ngọc Duy, Jul 14, 2013
  2. 01/46 clean: remove unused variable "seen"Nguyễn Thái Ngọc Duy, Jul 14, 2013
  3. 02/46 Move struct pathspec and related functions to pathspec.[ch]Nguyễn Thái Ngọc Duy, Jul 14, 2013
  4. 03/46 pathspec: i18n-ize error strings in pathspec parsing codeNguyễn Thái Ngọc Duy, Jul 14, 2013
  5. 04/46 pathspec: add copy_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  6. 05/46 Add parse_pathspec() that converts cmdline args to struct pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  7. 06/46 parse_pathspec: save original pathspec for reportingNguyễn Thái Ngọc Duy, Jul 14, 2013
  8. 07/46 parse_pathspec: add PATHSPEC_PREFER_{CWD,FULL}Nguyễn Thái Ngọc Duy, Jul 14, 2013
  9. 08/46 Convert some get_pathspec() calls to parse_pathspec()Nguyễn Thái Ngọc Duy, Jul 14, 2013
  10. 09/46 parse_pathspec: add special flag for max_depth featureNguyễn Thái Ngọc Duy, Jul 14, 2013
  11. 10/46 parse_pathspec: support stripping submodule trailing slashesNguyễn Thái Ngọc Duy, Jul 14, 2013
  12. 11/46 parse_pathspec: support stripping/checking submodule pathsNguyễn Thái Ngọc Duy, Jul 14, 2013
  13. 12/46 parse_pathspec: support prefixing original patternsNguyễn Thái Ngọc Duy, Jul 14, 2013
  14. 13/46 Guard against new pathspec magic in pathspec matching codeNguyễn Thái Ngọc Duy, Jul 14, 2013
  15. 14/46 clean: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  16. 15/46 commit: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  17. 16/46 status: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  18. 17/46 rerere: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  19. 18/46 checkout: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  20. 19/46 rm: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  21. 20/46 ls-files: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  22. 21/46 archive: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  23. 22/46 check-ignore: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  24. 23/46 add: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  25. 24/46 reset: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  26. 25/46 line-log: convert to use parse_pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  27. 26/46 Convert read_cache_preload() to take struct pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  28. 27/46 Convert run_add_interactive to use struct pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  29. 28/46 Convert unmerge_cache to take struct pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  30. 29/46 checkout: convert read_tree_some to take struct pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  31. 30/46 Convert report_path_error to take struct pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  32. 31/46 Convert refresh_index to take struct pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  33. 32/46 Convert {read,fill}_directory to take struct pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  34. 33/46 Convert add_files_to_cache to take struct pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  35. 34/46 Convert common_prefix() to use struct pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  36. 35/46 Remove diff_tree_{setup,release}_pathsNguyễn Thái Ngọc Duy, Jul 14, 2013
  37. 36/46 Remove init_pathspec() in favor of parse_pathspec()Nguyễn Thái Ngọc Duy, Jul 14, 2013
  38. 37/46 Remove match_pathspec() in favor of match_pathspec_depth()Nguyễn Thái Ngọc Duy, Jul 14, 2013
  39. 38/46 tree-diff: remove the use of pathspec's raw[] in follow-rename codepathNguyễn Thái Ngọc Duy, Jul 14, 2013
  40. 39/46 Rename field "raw" to "_raw" in struct pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  41. 40/46 parse_pathspec: make sure the prefix part is wildcard-freeNguyễn Thái Ngọc Duy, Jul 14, 2013
  42. 41/46 parse_pathspec: preserve prefix length via PATHSPEC_PREFIX_ORIGINNguyễn Thái Ngọc Duy, Jul 14, 2013
  43. 42/46 Kill limit_pathspec_to_literal() as it's only used by parse_pathspec()Nguyễn Thái Ngọc Duy, Jul 14, 2013
  44. 43/46 pathspec: support :(literal) syntax for noglob pathspecNguyễn Thái Ngọc Duy, Jul 14, 2013
  45. 44/46 pathspec: make --literal-pathspecs disable pathspec magicNguyễn Thái Ngọc Duy, Jul 14, 2013
  46. 45/46 pathspec: support :(glob) syntaxNguyễn Thái Ngọc Duy, Jul 14, 2013
  47. 46/46 parse_pathspec: accept :(icase)path syntaxNguyễn Thái Ngọc Duy, Jul 14, 2013
  48. Eric SunshineJul 14, 2013
  49. Junio C HamanoJul 15, 2013
  50. Junio C HamanoJul 15, 2013
  51. "git fmt-merge-msg" usage (was [PATCH v2 00/46] "struct pathspec" conversion and :(glob) and :(icase))Michael Haggerty, Aug 16, 2013
  52. Junio C HamanoAug 18, 2013

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