Our error() and die() calls may report messages with
arbitrary data (e.g., filenames or even data from a remote
server). Let's make it harder to cause confusion with
mischievous filenames. E.g., try:
git rev-parse "$(printf "\rfatal: this argument is too sneaky")" --
or
git rev-parse "$(printf "\x1b[5mblinky\x1b[0m")" --
Let's block all ASCII control characters, with the exception
of TAB and LF. We use both in our own messages (and we are
necessarily sanitizing the complete output of snprintf here,
as we do not have access to the individual varargs). And TAB
and LF are unlikely to cause confusion (you could put
"\nfatal: sneaky\n" in your filename, but it would at least
not _cover up_ the message leading to it, unlike "\r").
We'll replace the characters with a "?", which is similar to
how "ls" behaves. It might be nice to do something less
lossy, like converting them to "\x" hex codes. But replacing
with a single character makes it easy to do in-place and
without worrying about length limitations. This feature
should kick in rarely enough that the "?" marks are almost
never seen.
We'll leave high-bit characters as-is, as they are likely to
be UTF-8 (though there may be some Unicode mischief you
could cause, which may require further patches).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reverts commit f4c3edc0b1.
The purpose of that commit was to let us write errors of
arbitrary length to stderr by skipping the intermediate
buffer and sending our varargs straight to fprintf. That
works, but it comes with a downside: we do not get access to
the varargs before they are sent to stderr.
On balance, it's not a good tradeoff. Error messages larger
than our 4K buffer are quite uncommon, and we've lost the
ability to make any modifications to the output (e.g., to
remove non-printable characters).
The only way to have both would be one of:
1. Write into a dynamic buffer. But this is a bad idea for
a low-level function that may be called when malloc()
has failed.
2. Do our own printf-format varargs parsing. This is too
complex to be worth the trouble.
Let's just revert that change and go back to a fixed buffer.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we call "die(fmt, args...)", we end up in vreportf with
two pieces of information:
1. The prefix "fatal: "
2. The original fmt and va_list of args.
We format item (2) into a temporary buffer, and then fprintf
the prefix and the temporary buffer, along with a newline.
This has the unfortunate side effect of truncating any error
messages that are longer than 4096 bytes.
Instead, let's use separate calls for the prefix and
newline, letting us hand the item (2) directly to vfprintf.
This is essentially undoing d048a96 (print
warning/error/fatal messages in one shot, 2007-11-09), which
tried to have the whole output end up in a single `write`
call.
But we can address this instead by explicitly requesting
line-buffering for the output handle, and by making sure
that the buffer is empty before we start (so that outputting
the prefix does not cause a flush due to hitting the buffer
limit).
We may still break the output into two writes if the content
is larger than our buffer, but there's not much we can do
there; depending on the stdio implementation, that might
have happened even with a single fprintf call.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The vreportf function always goes to stderr, but run-command
wants child errors to go to the parent's original stderr. To
solve this, commit a5487dd duplicates the stderr fd and
installs die and error handlers to direct the output
appropriately (which later turned into the vwritef
function). This has two downsides, though:
- we make multiple calls to write(), which contradicts the
"write at once" logic from d048a96 (print
warning/error/fatal messages in one shot, 2007-11-09).
- the custom handlers basically duplicate the normal
handlers. They're only a few lines of code, but we
should not have to repeat the magic "exit(128)", for
example.
We can solve the first by using fdopen() on the duplicated
descriptor. We can't pass this to vreportf, but we could
introduce a new vreportf_to to handle it.
However, to fix the second problem, we instead introduce a
new "set_error_handle" function, which lets the normal
vreportf calls output to a handle besides stderr. Thus we
can get rid of our custom handlers entirely, and just ask
the regular handlers to output to our new descriptor.
And as vwritef has no more callers, it can just go away.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A regression fix for the logic to detect die() handler triggering
itself recursively.
* jk/a-thread-only-dies-once:
run-command: use thread-aware die_is_recursing routine
usage: allow pluggable die-recursion checks
When any git code calls die or die_errno, we use a counter
to detect recursion into the die functions from any of the
helper functions. However, such a simple counter is not good
enough for threaded programs, which may call die from a
sub-thread, killing only the sub-thread (but incrementing
the counter for everyone).
Rather than try to deal with threads ourselves here, let's
just allow callers to plug in their own recursion-detection
function. This is similar to how we handle the die routine
(the caller plugs in a die routine which may kill only the
sub-thread).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When git is compiled with "gcc -Wuninitialized -O3", some
inlined calls provide an additional opportunity for the
compiler to do static analysis on variable initialization.
For example, with two functions like this:
int get_foo(int *foo)
{
if (something_that_might_fail() < 0)
return error("unable to get foo");
*foo = 0;
return 0;
}
void some_fun(void)
{
int foo;
if (get_foo(&foo) < 0)
return -1;
printf("foo is %d\n", foo);
}
If get_foo() is not inlined, then when compiling some_fun,
gcc sees only that a pointer to the local variable is
passed, and must assume that it is an out parameter that
is initialized after get_foo returns.
However, when get_foo() is inlined, the compiler may look at
all of the code together and see that some code paths in
get_foo() do not initialize the variable. As a result, it
prints a warning. But what the compiler can't see is that
error() always returns -1, and therefore we know that either
we return early from some_fun, or foo ends up initialized,
and the code is safe. The warning is a false positive.
If we can make the compiler aware that error() will always
return -1, it can do a better job of analysis. The simplest
method would be to inline the error() function. However,
this doesn't work, because gcc will not inline a variadc
function. We can work around this by defining a macro. This
relies on two gcc extensions:
1. Variadic macros (these are present in C99, but we do
not rely on that).
2. Gcc treats the "##" paste operator specially between a
comma and __VA_ARGS__, which lets our variadic macro
work even if no format parameters are passed to
error().
Since we are using these extra features, we hide the macro
behind an #ifdef. This is OK, though, because our goal was
just to help gcc.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is theoretically possible for a die handler to get into a state of
infinite recursion. For example, if a die handler called another function
which itself called die(). Let's at least detect this situation, inform the
user, and call exit.
Signed-off-by: Brandon Casey <bcasey@nvidia.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The new process's error output may be redirected elsewhere, but if
the exec fails, output should still go to the parent's stderr. This
has already been done for the die_routine. Do the same for
error_routine.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix warnings from 'make check'.
- These files don't include 'builtin.h' causing sparse to complain that
cmd_* isn't declared:
builtin/clone.c:364, builtin/fetch-pack.c:797,
builtin/fmt-merge-msg.c:34, builtin/hash-object.c:78,
builtin/merge-index.c:69, builtin/merge-recursive.c:22
builtin/merge-tree.c:341, builtin/mktag.c:156, builtin/notes.c:426
builtin/notes.c:822, builtin/pack-redundant.c:596,
builtin/pack-refs.c:10, builtin/patch-id.c:60, builtin/patch-id.c:149,
builtin/remote.c:1512, builtin/remote-ext.c:240,
builtin/remote-fd.c:53, builtin/reset.c:236, builtin/send-pack.c:384,
builtin/unpack-file.c:25, builtin/var.c:75
- These files have symbols which should be marked static since they're
only file scope:
submodule.c:12, diff.c:631, replace_object.c:92, submodule.c:13,
submodule.c:14, trace.c:78, transport.c:195, transport-helper.c:79,
unpack-trees.c:19, url.c:3, url.c:18, url.c:104, url.c:117, url.c:123,
url.c:129, url.c:136, thread-utils.c:21, thread-utils.c:48
- These files redeclare symbols to be different types:
builtin/index-pack.c:210, parse-options.c:564, parse-options.c:571,
usage.c:49, usage.c:58, usage.c:63, usage.c:72
- These files use a literal integer 0 when they really should use a NULL
pointer:
daemon.c:663, fast-import.c:2942, imap-send.c:1072, notes-merge.c:362
While we're in the area, clean up some unused #includes in builtin files
(mostly exec_cmd.h).
Signed-off-by: Stephen Boyd <bebarino@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There exist already a number of static functions named 'report', therefore,
the function name was changed.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The usage messages for some commands (such as 'git diff-tree')
are truncated because they don't fit in a fixed buffer of
1024 bytes.
It would be tempting to eliminate the buffer and the problem once
and for all by doing the output in three steps, but doing so could
(according to commit d048a96e) increase the likelyhood of messing
up the display.
So we just increase the size of the buffer.
Signed-off-by: Björn Gustavsson <bgustavsson@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some new callers would want to use printf-like formatting, when issuing
their usage messages. An option is to change usage() itself also be like
printf(), which would make it similar to die() and warn().
But usage() is typically fixed, as opposed to die() and warn() that gives
diagnostics depending on the situation. Indeed, the majority of strings
given by existing callsites to usage() are fixed strings. If we were to
make usage() take printf-style format, they all need to be changed to have
"%s" as their first argument.
So instead, introduce usagef() so that limited number of callers can use
it.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some compilers (including at least MSVC and ARM RVDS) supports
NORETURN on function declarations, but not on function pointers.
This patch makes it possible to define NORETURN for these compilers,
by splitting the NORETURN macro into two - one for function
declarations and one for function pointers.
Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Some compilers (including at least MSVC) support NORETURN
on function declarations, but only before the function-name.
This patch makes it possible to define NORETURN to something
meaningful for those compilers.
Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
[tr: handle border case where % is placed at end of buffer]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are many calls to die() that do, or should, report
strerror(errno) to indicate how the syscall they guard failed.
Introduce a small helper function for this case.
Note:
- POSIX says vsnprintf can modify errno in some unlikely cases, so we
have to use errno early.
- We take some care to pass the original format to die_routine(), in
case someone wants to call die_errno() with custom format
characters.
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Long messages like those from lockfile.c when a lock can't be
obtained truncate with only 256 bytes in the message buffer.
Bump it to 1024 to give more space for these longer cases.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This removes three functions that are not used anywhere.
Signed-off-by: Nanako Shiraishi <nanako3@lavabit.com>
Acked-by: Lars Hjemli <hjemli@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Not doing so is likely to create a messed up display when sent over the
sideband protocol.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This fixes a problem reported by Randal Schwartz:
>I finally tracked down all the (albeit inconsequential) errors I was getting
>on both OpenBSD and OSX. It's the warn() function in usage.c. There's
>warn(3) in BSD-style distros. It'd take a "great rename" to change it, but if
>someone with better C skills than I have could do that, my linker and I would
>appreciate it.
It was annoying to me, too, when I was doing some mergetool testing on
Mac OS X, so here's a fix.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: "Randal L. Schwartz" <merlyn@stonehenge.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Like the existing error() function the new warn() function can be
used to describe a situation that probably should not be occuring,
but which the user (and Git) can continue to work around without
running into too many problems.
An example situation is a bad commit SHA1 found in a reflog.
Attempting to read this record out of the reflog isn't really an
error as we have skipped over it in the past.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This patch makes the usage(), die() and error() handlers customizable.
Nothing in the git code itself uses that but many other libgit users
(like Git.pm) will.
This is implemented using the mutator functions primarily because you
cannot directly modifying global variables of libgit from a program that
dlopen()ed it, apparently. But having functions for that is a better API
anyway.
Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This attempts to clean up the way various compatibility
functions are defined and used.
- A new header file, git-compat-util.h, is introduced. This
looks at various NO_XXX and does necessary function name
replacements, equivalent of -Dstrcasestr=gitstrcasestr in the
Makefile.
- Those function name replacements are removed from the Makefile.
- Common features such as usage(), die(), xmalloc() are moved
from cache.h to git-compat-util.h; cache.h includes
git-compat-util.h itself.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Instead of "git status" ignoring (and hiding) potential errors from the
"git-update-index" call, make it exit if it fails, and show the error.
In order to do this, use the "-q" flag (to ignore not-up-to-date files)
and add a new "--unmerged" flag that allows unmerged entries in the index
without any errors.
This also avoids marking the index "changed" if an entry isn't actually
modified, and makes sure that we exit with an understandable error message
if the index is corrupt or unreadable. "read_cache()" no longer returns an
error for the caller to check.
Finally, make die() and usage() exit with recognizable error codes, if we
ever want to check the failure reason in scripts.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Add <limits.h> to the include files handled by "cache.h", and remove
extraneous #include directives from various .c files. The rule is that
"cache.h" gets all the basic stuff, so that we'll have as few system
dependencies as possible.
