git/Makefile, branch v2.25.2

Merge branch 'jk/asan-build-fix' into maint

2020-02-14T20:42:29Z

Work around test breakages caused by custom regex engine used in libasan, when address sanitizer is used with more recent versions of gcc and clang. * jk/asan-build-fix: Makefile: use compat regex with SANITIZE=address

Makefile: use compat regex with SANITIZE=address

2020-01-16T22:19:39Z

Recent versions of the gcc and clang Address Sanitizer produce test failures related to regexec(). This triggers with gcc-10 and clang-8 (but not gcc-9 nor clang-7). Running: make CC=gcc-10 SANITIZE=address test results in failures in t4018, t3206, and t4062. The cause seems to be that when built with ASan, we use a different version of regexec() than normal. And this version doesn't understand the REG_STARTEND flag. Here's my evidence supporting that. The failure in t4062 is an ASan warning: expecting success of 4062.2 '-G matches': git diff --name-only -G "^(0{64}){64}$" HEAD^ >out && test 4096-zeroes.txt = "$(cat out)" ================================================================= ==672994==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7fa76f672000 at pc 0x7fa7726f75b6 bp 0x7ffe41bdda70 sp 0x7ffe41bdd220 READ of size 4097 at 0x7fa76f672000 thread T0 #0 0x7fa7726f75b5 (/lib/x86_64-linux-gnu/libasan.so.6+0x4f5b5) #1 0x562ae0c9c40e in regexec_buf /home/peff/compile/git/git-compat-util.h:1117 #2 0x562ae0c9c40e in diff_grep /home/peff/compile/git/diffcore-pickaxe.c:52 #3 0x562ae0c9cc28 in pickaxe_match /home/peff/compile/git/diffcore-pickaxe.c:166 [...] In this case we're looking in a buffer which was mmap'd via reuse_worktree_file(), and whose size is 4096 bytes. But libasan's regex tries to look at byte 4097 anyway! If we tweak Git like this: diff --git a/diff.c b/diff.c index 8e2914c031..cfae60c120 100644 --- a/diff.c +++ b/diff.c @@ -3880,7 +3880,7 @@ static int reuse_worktree_file(struct index_state *istate, */ if (ce_uptodate(ce) || (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0))) - return 1; + return 0; return 0; } to use a regular buffer (with a trailing NUL) instead of an mmap, then the complaint goes away. The other failures are actually diff output with an incorrect funcname header. If I instrument xdiff to show the funcname matching like so: diff --git a/xdiff-interface.c b/xdiff-interface.c index 8509f9ea22..f6c3dc1986 100644 --- a/xdiff-interface.c +++ b/xdiff-interface.c @@ -197,6 +197,7 @@ struct ff_regs { struct ff_reg { regex_t re; int negate; + char *printable; } *array; }; @@ -218,7 +219,12 @@ static long ff_regexp(const char *line, long len, for (i = 0; i < regs->nr; i++) { struct ff_reg *reg = regs->array + i; - if (!regexec_buf(®->re, line, len, 2, pmatch, 0)) { + int ret = regexec_buf(®->re, line, len, 2, pmatch, 0); + warning("regexec %s:\n regex: %s\n buf: %.*s", + ret == 0 ? "matched" : "did not match", + reg->printable, + (int)len, line); + if (!ret) { if (reg->negate) return -1; break; @@ -264,6 +270,7 @@ void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags) expression = value; if (regcomp(®->re, expression, cflags)) die("Invalid regexp to look for hunk header: %s", expression); + reg->printable = xstrdup(expression); free(buffer); value = ep + 1; } then when compiling with ASan and gcc-10, running the diff from t4018.66 produces this: $ git diff -U1 cpp-skip-access-specifiers warning: regexec did not match: regex: ^[ ]*[A-Za-z_][A-Za-z_0-9]*:[[:space:]]*($|/[/*]) buf: private: warning: regexec matched: regex: ^((::[[:space:]]*)?[A-Za-z_].*)$ buf: private: diff --git a/cpp-skip-access-specifiers b/cpp-skip-access-specifiers index 4d4a9db..ebd6f42 100644 --- a/cpp-skip-access-specifiers +++ b/cpp-skip-access-specifiers @@ -6,3 +6,3 @@ private: void DoSomething(); int ChangeMe; }; void DoSomething(); - int ChangeMe; + int IWasChanged; }; That first regex should match (and is negated, so it should be telling us _not_ to match "private:"). But it wouldn't if regexec() is looking at the whole buffer, and not just the length-limited line we've fed to regexec_buf(). So this is consistent again with REG_STARTEND being ignored. The correct output (compiling without ASan, or gcc-9 with Asan) looks like this: warning: regexec matched: regex: ^[ ]*[A-Za-z_][A-Za-z_0-9]*:[[:space:]]*($|/[/*]) buf: private: [...more lines that we end up not using...] warning: regexec matched: regex: ^((::[[:space:]]*)?[A-Za-z_].*)$ buf: class RIGHT : public Baseclass diff --git a/cpp-skip-access-specifiers b/cpp-skip-access-specifiers index 4d4a9db..ebd6f42 100644 --- a/cpp-skip-access-specifiers +++ b/cpp-skip-access-specifiers @@ -6,3 +6,3 @@ class RIGHT : public Baseclass void DoSomething(); - int ChangeMe; + int IWasChanged; }; So it really does seem like libasan's regex engine is ignoring REG_STARTEND. We should be able to work around it by compiling with NO_REGEX, which would use our local regexec(). But to make matters even more interesting, this isn't enough by itself. Because ASan has support from the compiler, it doesn't seem to intercept our call to regexec() at the dynamic library level. It actually recognizes when we are compiling a call to regexec() and replaces it with ASan-specific code at that point. And unlike most of our other compat code, where we might have git_mmap() or similar, the actual symbol name in the compiled compat/regex code is regexec(). So just compiling with NO_REGEX isn't enough; we still end up in libasan! We can work around that by having the preprocessor replace regexec with git_regexec (both in the callers and in the actual implementation), and we truly end up with a call to our custom regex code, even when compiling with ASan. That's probably a good thing to do anyway, as it means anybody looking at the symbols later (e.g., in a debugger) would have a better indication of which function is which. So we'll do the same for the other common regex functions (even though just regexec() is enough to fix this ASan problem). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Merge branch 'js/add-p-in-c'

2019-12-25T19:22:01Z

The effort to move "git-add--interactive" to C continues. * js/add-p-in-c: built-in add -p: show helpful hint when nothing can be staged built-in add -p: only show the applicable parts of the help text built-in add -p: implement the 'q' ("quit") command built-in add -p: implement the '/' ("search regex") command built-in add -p: implement the 'g' ("goto") command built-in add -p: implement hunk editing strbuf: add a helper function to call the editor "on an strbuf" built-in add -p: coalesce hunks after splitting them built-in add -p: implement the hunk splitting feature built-in add -p: show different prompts for mode changes and deletions built-in app -p: allow selecting a mode change as a "hunk" built-in add -p: handle deleted empty files built-in add -p: support multi-file diffs built-in add -p: offer a helpful error message when hunk navigation failed built-in add -p: color the prompt and the help text built-in add -p: adjust hunk headers as needed built-in add -p: show colored hunks by default built-in add -i: wire up the new C code for the `patch` command built-in add -i: start implementing the `patch` functionality in C

Merge branch 'jc/drop-gen-hdrs'

2019-12-25T19:22:00Z

Code cleanup. * jc/drop-gen-hdrs: Makefile: drop GEN_HDRS

Merge branch 'ds/sparse-cone'

2019-12-25T19:21:58Z

Management of sparsely checked-out working tree has gained a dedicated "sparse-checkout" command. * ds/sparse-cone: (21 commits) sparse-checkout: improve OS ls compatibility sparse-checkout: respect core.ignoreCase in cone mode sparse-checkout: check for dirty status sparse-checkout: update working directory in-process for 'init' sparse-checkout: cone mode should not interact with .gitignore sparse-checkout: write using lockfile sparse-checkout: use in-process update for disable subcommand sparse-checkout: update working directory in-process sparse-checkout: sanitize for nested folders unpack-trees: add progress to clear_ce_flags() unpack-trees: hash less in cone mode sparse-checkout: init and set in cone mode sparse-checkout: use hashmaps for cone patterns sparse-checkout: add 'cone' mode trace2: add region in clear_ce_flags sparse-checkout: create 'disable' subcommand sparse-checkout: add '--stdin' option to set subcommand sparse-checkout: 'set' subcommand clone: add --sparse mode sparse-checkout: create 'init' subcommand ...

fix-typo: consecutive-word duplications

2019-12-16T19:53:11Z

Correct unintentional duplication(s) of words, such as "the the", and "can can" etc. The changes are only applied to cases where it's fixing what is clearly wrong or prone to misunderstanding, as suggested by the reviewers. Helped-by: Johannes Schindelin Helped-by: Denton Liu Helped-by: Junio C Hamano Signed-off-by: ryenus Signed-off-by: Junio C Hamano

Makefile: drop GEN_HDRS

2019-12-13T23:15:34Z

When ebb7baf0 ("Makefile: add a hdr-check target", 2018-09-19) implemented hdr-check target, it wanted to leave some header files exempt from the stricter check the target implements, and added GEN_HDRS macro. This however is probably a bad move for two reasons: - If we value the header cleanliness check, we eventually want to teach our header generating scripts to produce clean headers. Keeping the blanket "generated headers can be left as dirty as we want" exception does not nudge us in the right direction. - There is a list of generated header files, GENERATED_H, which is used to keep track of dependencies. Presence of GEN_HDRS that is too similarly named would confuse developers who are adding new generated header files which list to add theirs. - Even though unicode-width.h could be generated using a contrib/ script, as far as our build infrastructure is concerned, it is a source file that is tracked in the source control system. Its presence in GEN_HDRS list is doubly misleading. Get rid of GEN_HDRS, which is used only once to list the headers we do not run hdr-check test on, and instead explicitly list that the ones, either tracked or generated, that we exempt from the test. This allows GENERATED_H to be the sole "here are build artifact header files that are expendable" list, so use it in the clean target to $(RM) them. Signed-off-by: Junio C Hamano

built-in add -i: start implementing the `patch` functionality in C

2019-12-13T20:37:13Z

In the previous steps, we re-implemented the main loop of `git add -i` in C, and most of the commands. Notably, we left out the actual functionality of `patch`, as the relevant code makes up more than half of `git-add--interactive.perl`, and is actually pretty independent of the rest of the commands. With this commit, we start to tackle that `patch` part. For better separation of concerns, we keep the code in a separate file, `add-patch.c`. The new code is still guarded behind the `add.interactive.useBuiltin` config setting, and for the moment, it can only be called via `git add -p`. The actual functionality follows the original implementation of 5cde71d64aff (git-add --interactive, 2006-12-10), but not too closely (for example, we use string offsets rather than copying strings around, and after seeing whether the `k` and `j` commands are applicable, in the C version we remember which previous/next hunk was undecided, and use it rather than looking again when the user asked to jump). As a further deviation from that commit, We also use a comma instead of a slash to separate the available commands in the prompt, as the current version of the Perl script does this, and we also add a line about the question mark ("print help") to the help text. While it is tempting to use this conversion of `git add -p` as an excuse to work on `apply_all_patches()` so that it does _not_ want to read a file from `stdin` or from a file, but accepts, say, an `strbuf` instead, we will refrain from this particular rabbit hole at this stage. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano

Merge branch 'js/builtin-add-i'

2019-12-05T20:52:43Z

The beginning of rewriting "git add -i" in C. * js/builtin-add-i: built-in add -i: implement the `help` command built-in add -i: use color in the main loop built-in add -i: support `?` (prompt help) built-in add -i: show unique prefixes of the commands built-in add -i: implement the main loop built-in add -i: color the header in the `status` command built-in add -i: implement the `status` command diff: export diffstat interface Start to implement a built-in version of `git add --interactive`

sparse-checkout: create builtin with 'list' subcommand

2019-11-22T07:11:43Z

The sparse-checkout feature is mostly hidden to users, as its only documentation is supplementary information in the docs for 'git read-tree'. In addition, users need to know how to edit the .git/info/sparse-checkout file with the right patterns, then run the appropriate 'git read-tree -mu HEAD' command. Keeping the working directory in sync with the sparse-checkout file requires care. Begin an effort to make the sparse-checkout feature a porcelain feature by creating a new 'git sparse-checkout' builtin. This builtin will be the preferred mechanism for manipulating the sparse-checkout file and syncing the working directory. The documentation provided is adapted from the "git read-tree" documentation with a few edits for clarity in the new context. Extra sections are added to hint toward a future change to a more restricted pattern set. Helped-by: Elijah Newren Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano