Commit Graph

23 Commits

Author SHA1 Message Date
Ævar Arnfjörð Bjarmason
5cf88fd8b0 git-compat-util.h: use "UNUSED", not "UNUSED(var)"
As reported in [1] the "UNUSED(var)" macro introduced in
2174b8c75de (Merge branch 'jk/unused-annotation' into next,
2022-08-24) breaks coccinelle's parsing of our sources in files where
it occurs.

Let's instead partially go with the approach suggested in [2] of
making this not take an argument. As noted in [1] "coccinelle" will
ignore such tokens in argument lists that it doesn't know about, and
it's less of a surprise to syntax highlighters.

This undoes the "help us notice when a parameter marked as unused is
actually use" part of 9b24034754 (git-compat-util: add UNUSED macro,
2022-08-19), a subsequent commit will further tweak the macro to
implement a replacement for that functionality.

1. https://lore.kernel.org/git/220825.86ilmg4mil.gmgdl@evledraar.gmail.com/
2. https://lore.kernel.org/git/220819.868rnk54ju.gmgdl@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-01 10:49:48 -07:00
Jeff King
02c3c59e62 hashmap: mark unused callback parameters
Hashmap comparison functions must conform to a particular callback
interface, but many don't use all of their parameters. Especially the
void cmp_data pointer, but some do not use keydata either (because they
can easily form a full struct to pass when doing lookups). Let's mark
these to make -Wunused-parameter happy.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 12:18:55 -07:00
Phillip Wood
0f584debc7 terminal: restore settings on SIGTSTP
If the user suspends git while it is waiting for a keypress reset the
terminal before stopping and restore the settings when git resumes. If
the user tries to resume in the background print an error
message (taking care to use async safe functions) before stopping
again. Ideally we would reprint the prompt for the user when git
resumes but this patch just restarts the read().

The signal handler is established with sigaction() rather than using
sigchain_push() as this allows us to control the signal mask when the
handler is invoked and ensure SA_RESTART is used to restart the
read() when resuming.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-16 12:24:44 -07:00
Phillip Wood
6606d99bae terminal: work around macos poll() bug
On macos the builtin "add -p" does not handle keys that generate
escape sequences because poll() does not work with terminals
there. Switch to using select() on non-windows platforms to work
around this.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-16 12:24:44 -07:00
Phillip Wood
e4938ce3cc terminal: don't assume stdin is /dev/tty
read_key_without_echo() reads from stdin but uses /dev/tty when it
disables echo. This is unfortunate as there no guarantee that stdin is
the same device as /dev/tty. The perl version of "add -p" uses stdin
when it sets the terminal mode, this commit does the same for the
builtin version. There is still a difference between the perl and
builtin versions though - the perl version will ignore any errors when
setting the terminal mode[1] and will still read single bytes when
stdin is not a terminal. The builtin version displays a warning if
setting the terminal mode fails and switches to reading a line at a
time.

[1] b061c913bb/ReadKey.xs (L1090)

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-16 12:24:43 -07:00
Phillip Wood
02af15dec5 terminal: use flags for save_term()
The next commit will add another flag in addition to the existing
full_duplex so change the function signature to take a flags
argument. Also alter the functions that call save_term() so that they
can pass flags down to it.

The choice to use an enum for tho bitwise flags is because gdb will
display the symbolic names of all the flags that are set rather than
the integer value.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-16 12:24:43 -07:00
Phillip Wood
2c6860211f terminal: set VMIN and VTIME in non-canonical mode
If VMIN and VTIME are both set to zero then the terminal performs
non-blocking reads which means that read_key_without_echo() returns
EOF if there is no key press pending. This results in the user being
unable to select anything when running "git add -p".  Fix this by
explicitly setting VMIN and VTIME when enabling non-canonical mode.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-23 13:30:06 -08:00
Phillip Wood
f7da756566 terminal: pop signal handler when terminal is restored
When disable_bits() changes the terminal attributes it uses
sigchain_push_common() to restore the terminal if a signal is received
before restore_term() is called. However there is no corresponding
call to sigchain_pop_common() when the settings are restored so the
signal handler is left on the sigchain stack. This leaves the stack
unbalanced so code such as

sigchain_push_common(my_handler);
...
read_key_without_echo(...);
...
sigchain_pop_common();

pops the handler pushed by disable_bits() rather than the one it
intended to. Additionally "git add -p" changes the terminal settings
every time it reads a key press so the stack can grow significantly.

In order to fix this save_term() now sets up the signal handler so
restore_term() can unconditionally call sigchain_pop_common(). There
are no callers of save_term() outside of terminal.c as the only
external caller was removed by e3f7e01b50 ("Revert "editor: save and
reset terminal after calling EDITOR"", 2021-11-22). Any future callers
of save_term() should benefit from having the signal handler set up
for them.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-23 13:30:06 -08:00
Phillip Wood
24d7ce383a terminal: always reset terminal when reading without echo
Break out of the loop to ensure restore_term() is called before
returning.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-23 13:30:06 -08:00
Carlo Marcelo Arenas Belón
e22b245ea5 terminal: teach git how to save/restore its terminal settings
Currently, git will share its console with all its children (unless
they create their own), and is therefore possible that any of them
that might change the settings for it could affect its operations once
completed.

Refactor the platform specific functionality to save the terminal
settings and expand it to also do so for the output handler.

This will allow for the state of the terminal to be saved and
restored around a child that might misbehave (ex vi) which will
be implemented next.

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-06 08:53:00 -07:00
Jeff King
ef8d7ac42a strvec: convert more callers away from argv_array name
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).

This patch converts remaining files from the first half of the alphabet,
to keep the diff to a manageable size.

The conversion was done purely mechanically with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe '
    s/ARGV_ARRAY/STRVEC/g;
    s/argv_array/strvec/g;
  '

and then selectively staging files with "git add '[abcdefghjkl]*'".
We'll deal with any indentation/style fallouts separately.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:18 -07:00
Johannes Schindelin
12acdf573a built-in add -p: handle Escape sequences more efficiently
When `interactive.singlekey = true`, we react immediately to keystrokes,
even to Escape sequences (e.g. when pressing a cursor key).

The problem with Escape sequences is that we do not really know when
they are done, and as a heuristic we poll standard input for half a
second to make sure that we got all of it.

While waiting half a second is not asking for a whole lot, it can become
quite annoying over time, therefore with this patch, we read the
terminal capabilities (if available) and extract known Escape sequences
from there, then stop polling immediately when we detected that the user
pressed a key that generated such a known sequence.

This recapitulates the remaining part of b5cc003253 (add -i: ignore
terminal escape sequences, 2011-05-17).

Note: We do *not* query the terminal capabilities directly. That would
either require a lot of platform-specific code, or it would require
linking to a library such as ncurses.

Linking to a library in the built-ins is something we try very hard to
avoid (we even kicked the libcurl dependency to a non-built-in remote
helper, just to shave off a tiny fraction of a second from Git's startup
time). And the platform-specific code would be a maintenance nightmare.

Even worse: in Git for Windows' case, we would need to query MSYS2
pseudo terminals, which `git.exe` simply cannot do (because it is
intentionally *not* an MSYS2 program).

To address this, we simply spawn `infocmp -L -1` and parse its output
(which works even in Git for Windows, because that helper is included in
the end-user facing installations).

This is done only once, as in the Perl version, but it is done only when
the first Escape sequence is encountered, not upon startup of `git add
-i`; This saves on startup time, yet makes reacting to the first Escape
sequence slightly more sluggish. But it allows us to keep the
terminal-related code encapsulated in the `compat/terminal.c` file.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00
Johannes Schindelin
e118f06396 built-in add -p: handle Escape sequences in interactive.singlekey mode
This recapitulates part of b5cc003253 (add -i: ignore terminal escape
sequences, 2011-05-17):

    add -i: ignore terminal escape sequences

    On the author's terminal, the up-arrow input sequence is ^[[A, and
    thus fat-fingering an up-arrow into 'git checkout -p' is quite
    dangerous: git-add--interactive.perl will ignore the ^[ and [
    characters and happily treat A as "discard everything".

    As a band-aid fix, use Term::Cap to get all terminal capabilities.
    Then use the heuristic that any capability value that starts with ^[
    (i.e., \e in perl) must be a key input sequence.  Finally, given an
    input that starts with ^[, read more characters until we have read a
    full escape sequence, then return that to the caller.  We use a
    timeout of 0.5 seconds on the subsequent reads to avoid getting stuck
    if the user actually input a lone ^[.

    Since none of the currently recognized keys start with ^[, the net
    result is that the sequence as a whole will be ignored and the help
    displayed.

Note that we leave part for later which uses "Term::Cap to get all
terminal capabilities", for several reasons:

1. it is actually not really necessary, as the timeout of 0.5 seconds
   should be plenty sufficient to catch Escape sequences,

2. it is cleaner to keep the change to special-case Escape sequences
   separate from the change that reads all terminal capabilities to
   speed things up, and

3. in practice, relying on the terminal capabilities is a bit overrated,
   as the information could be incomplete, or plain wrong. For example,
   in this developer's tmux sessions, the terminal capabilities claim
   that the "cursor up" sequence is ^[M, but the actual sequence
   produced by the "cursor up" key is ^[[A.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00
Johannes Schindelin
a5e46e6b01 terminal: add a new function to read a single keystroke
Typically, input on the command-line is line-based. It is actually not
really easy to get single characters (or better put: keystrokes).

We provide two implementations here:

- One that handles `/dev/tty` based systems as well as native Windows.
  The former uses the `tcsetattr()` function to put the terminal into
  "raw mode", which allows us to read individual keystrokes, one by one.
  The latter uses `stty.exe` to do the same, falling back to direct
  Win32 Console access.

  Thanks to the refactoring leading up to this commit, this is a single
  function, with the platform-specific details hidden away in
  conditionally-compiled code blocks.

- A fall-back which simply punts and reads back an entire line.

Note that the function writes the keystroke into an `strbuf` rather than
a `char`, in preparation for reading Escape sequences (e.g. when the
user hit an arrow key). This is also required for UTF-8 sequences in
case the keystroke corresponds to a non-ASCII letter.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00
Johannes Schindelin
9ea416cb51 terminal: accommodate Git for Windows' default terminal
Git for Windows' Git Bash runs in MinTTY by default, which does not have
a Win32 Console instance, but uses MSYS2 pseudo terminals instead.

This is a problem, as Git for Windows does not want to use the MSYS2
emulation layer for Git itself, and therefore has no direct way to
interact with that pseudo terminal.

As a workaround, use the `stty` utility (which is included in Git for
Windows, and which *is* an MSYS2 program, so it knows how to deal with
the pseudo terminal).

Note: If Git runs in a regular CMD or PowerShell window, there *is* a
regular Win32 Console to work with. This is not a problem for the MSYS2
`stty`: it copes with this scenario just fine.

Also note that we introduce support for more bits than would be
necessary for a mere `disable_echo()` here, in preparation for the
upcoming `enable_non_canonical()` function.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00
Johannes Schindelin
94ac3c31f7 terminal: make the code of disable_echo() reusable
We are about to introduce the function `enable_non_canonical()`, which
shares almost the complete code with `disable_echo()`.

Let's prepare for that, by refactoring out that shared code.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00
Junio C Hamano
8f309aeb82 strbuf: introduce strbuf_getline_{lf,nul}()
The strbuf_getline() interface allows a byte other than LF or NUL as
the line terminator, but this is only because I wrote these
codepaths anticipating that there might be a value other than NUL
and LF that could be useful when I introduced line_termination long
time ago.  No useful caller that uses other value has emerged.

By now, it is clear that the interface is overly broad without a
good reason.  Many codepaths have hardcoded preference to read
either LF terminated or NUL terminated records from their input, and
then call strbuf_getline() with LF or NUL as the third parameter.

This step introduces two thin wrappers around strbuf_getline(),
namely, strbuf_getline_lf() and strbuf_getline_nul(), and
mechanically rewrites these call sites to call either one of
them.  The changes contained in this patch are:

 * introduction of these two functions in strbuf.[ch]

 * mechanical conversion of all callers to strbuf_getline() with
   either '\n' or '\0' as the third parameter to instead call the
   respective thin wrapper.

After this step, output from "git grep 'strbuf_getline('" would
become a lot smaller.  An interim goal of this series is to make
this an empty set, so that we can have strbuf_getline_crlf() take
over the shorter name strbuf_getline().

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-15 10:12:51 -08:00
Jonathan Nieder
380395d094 mingw: rename WIN32 cpp macro to GIT_WINDOWS_NATIVE
Throughout git, it is assumed that the WIN32 preprocessor symbol is
defined on native Windows setups (mingw and msvc) and not on Cygwin.
On Cygwin, most of the time git can pretend this is just another Unix
machine, and Windows-specific magic is generally counterproductive.

Unfortunately Cygwin *does* define the WIN32 symbol in some headers.
Best to rely on a new git-specific symbol GIT_WINDOWS_NATIVE instead,
defined as follows:

	#if defined(WIN32) && !defined(__CYGWIN__)
	# define GIT_WINDOWS_NATIVE
	#endif

After this change, it should be possible to drop the
CYGWIN_V15_WIN32API setting without any negative effect.

[rj: %s/WINDOWS_NATIVE/GIT_WINDOWS_NATIVE/g ]

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-08 12:14:35 -07:00
Erik Faye-Lund
afb43561b8 mingw: reuse tty-version of git_terminal_prompt
The getpass-implementation we use on Windows isn't at all ideal;
it works in raw-mode (as opposed to cooked mode), and as a result
does not deal correcly with deletion, arrow-keys etc.

Instead, use cooked mode to read a line at the time, allowing the
C run-time to process the input properly.

Since we set files to be opened in binary-mode by default on
Windows, introduce a FORCE_TEXT macro that expands to the "t"
modifier that forces the terminal to be opened in text-mode so we
do not have to deal with CRLF issues.

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-12-04 08:03:08 -08:00
Erik Faye-Lund
67fe735653 compat/terminal: separate input and output handles
On Windows, the terminal cannot be opened in read-write mode, so
we need distinct pairs for reading and writing. Since this works
fine on other platforms as well, always open them in pairs.

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-12-04 08:02:55 -08:00
Erik Faye-Lund
9df92e6369 compat/terminal: factor out echo-disabling
By moving the echo-disabling code to a separate function, we can
implement OS-specific versions of it for non-POSIX platforms.

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-12-04 08:01:59 -08:00
Jeff King
67ba123fd1 terminal: seek when switching between reading and writing
When a stdio stream is opened in update mode (e.g., "w+"),
the C standard forbids switching between reading or writing
without an intervening positioning function. Many
implementations are lenient about this, but Solaris libc
will flush the recently-read contents to the output buffer.
In this instance, that meant writing the non-echoed password
that the user just typed to the terminal.

Fix it by inserting a no-op fseek between the read and
write.

The opposite direction (writing followed by reading) is also
disallowed, but our intervening fflush is an acceptable
positioning function for that alternative.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-08-06 22:11:47 -07:00
Jeff King
21aeafceda add generic terminal prompt function
When we need to prompt the user for input interactively, we
want to access their terminal directly. We can't rely on
stdio because it may be connected to pipes or files, rather
than the terminal. Instead, we use "getpass()", because it
abstracts the idea of prompting and reading from the
terminal.  However, it has some problems:

  1. It never echoes the typed characters, which makes it OK
     for passwords but annoying for other input (like usernames).

  2. Some implementations of getpass() have an extremely
     small input buffer (e.g., Solaris 8 is reported to
     support only 8 characters).

  3. Some implementations of getpass() will fall back to
     reading from stdin (e.g., glibc). We explicitly don't
     want this, because our stdin may be connected to a pipe
     speaking a particular protocol, and reading will
     disrupt the protocol flow (e.g., the remote-curl
     helper).

  4. Some implementations of getpass() turn off signals, so
     that hitting "^C" on the terminal does not break out of
     the password prompt. This can be a mild annoyance.

Instead, let's provide an abstract "git_terminal_prompt"
function that addresses these concerns. This patch includes
an implementation based on /dev/tty, enabled by setting
HAVE_DEV_TTY. The fallback is to use getpass() as before.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-12-12 16:09:38 -08:00