By default, CreateProcess() does not inherit any open file handles,
unless the bInheritHandles parameter is set to TRUE. Which we do need to
set because we need to pass in stdin/stdout/stderr to talk to the child
processes. Sadly, this means that all file handles (unless marked via
O_NOINHERIT) are inherited.
This lead to problems in GVFS Git, where a long-running read-object hook
is used to hydrate missing objects, and depending on the circumstances,
might only be called *after* Git opened a file handle.
Ideally, we would not open files without O_NOINHERIT unless *really*
necessary (i.e. when we want to pass the opened file handle as standard
handle into a child process), but apparently it is all-too-easy to
introduce incorrect open() calls: this happened, and prevented updating
a file after the read-object hook was started because the hook still
held a handle on said file.
Happily, there is a solution: as described in the "Old New Thing"
https://blogs.msdn.microsoft.com/oldnewthing/20111216-00/?p=8873 there
is a way, starting with Windows Vista, that lets us define precisely
which handles should be inherited by the child process.
And since we bumped the minimum Windows version for use with Git for
Windows to Vista with v2.10.1 (i.e. a *long* time ago), we can use this
method. So let's do exactly that.
We need to make sure that the list of handles to inherit does not
contain duplicates; Otherwise CreateProcessW() would fail with
ERROR_INVALID_ARGUMENT.
While at it, stop setting errno to ENOENT unless it really is the
correct value.
Also, fall back to not limiting handle inheritance under certain error
conditions (e.g. on Windows 7, which is a lot stricter in what handles
you can specify to limit to).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This patch should logically come before the patch which tries to limit
the list of file handles to be inherited by spawned processes, to avoid
introducing a regression before resolving it.
mingw: work around incorrect standard handles
For some reason, when being called via TortoiseGit the standard handles,
or at least what is returned by _get_osfhandle(0) for standard input,
can take on the value (HANDLE)-2 (which is not a legal value, according
to the documentation).
Even if this value is not documented anywhere, CreateProcess() seems to
work fine without complaints if hStdInput set to this value.
In contrast, the upcoming code to restrict which file handles get
inherited by spawned processes would result in `ERROR_INVALID_PARAMETER`
when including such handle values in the list.
To help this, special-case the value (HANDLE)-2 returned by
_get_osfhandle() and replace it with INVALID_HANDLE_VALUE, which will
hopefully let the handle inheritance restriction work even when called
from TortoiseGit.
This fixes https://github.com/git-for-windows/git/issues/1481
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Quite some time ago, a last plea to the XP users out there who want to
see Windows XP support in Git for Windows, asking them to get engaged
and help, vanished into the depths of the universe.
It is time to codify the ascent by the "silent majority" of XP users,
and mark the minimum Windows version required for Git for Windows as
Windows Vista.
This, incidentally, lets us use quite a few nice new APIs.
This also means that we no longer need the inet_pton() and inet_ntop()
emulation, and we no longer need to do the PROC_ADDR dance with the
`CreateSymbolicLinkW()` function, either.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Windows Vista (and later) actually have a working poll(), but we still
cannot use it because it only works on sockets.
So let's detect when we are targeting Windows Vista and undefine those
constants, and define `pollfd` so that we can declare our own pollfd
struct.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
From the documentation of said setting:
This boolean will enable fsync() when writing object files.
This is a total waste of time and effort on a filesystem that
orders data writes properly, but can be useful for filesystems
that do not use journalling (traditional UNIX filesystems) or
that only journal metadata and not file contents (OS X’s HFS+,
or Linux ext3 with "data=writeback").
The most common file system on Windows (NTFS) does not guarantee that
order, therefore a sudden loss of power (or any other event causing an
unclean shutdown) would cause corrupt files (i.e. files filled with
NULs). Therefore we need to change the default.
Note that the documentation makes it sound as if this causes really bad
performance. In reality, writing loose objects is something that is done
only rarely, and only a handful of files at a time.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Make fscache_enabled() function public rather than static.
Remove unneeded fscache_is_enabled() function.
Change is_fscache_enabled() macro to call fscache_enabled().
is_fscache_enabled() now takes a pathname so that the answer
is more precise and mean "is fscache enabled for this pathname",
since fscache only stores repo-relative paths and not absolute
paths, we can avoid attempting lookups for absolute paths.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
In Git for Windows' SDK, there is already a script to package Git for
Windows as a NuGet package, downloading nuget.exe if needed.
Let's just fall back to using that executable (if it is there) if
nuget.exe was not found in the PATH.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Teach read_directory_recursive() and add_excludes() to
be aware of optional fscache and avoid trying to open()
and fstat() non-existant ".gitignore" files in every
directory in the worktree.
The current code in add_excludes() calls open() and then
fstat() for a ".gitignore" file in each directory present
in the worktree. Change that when fscache is enabled to
call lstat() first and if present, call open().
This seems backwards because both lstat needs to do more
work than fstat. But when fscache is enabled, fscache will
already know if the .gitignore file exists and can completely
avoid the IO calls. This works because of the lstat diversion
to mingw_lstat when fscache is enabled.
This reduced status times on a 350K file enlistment of the
Windows repo on a NVMe SSD by 0.25 seconds.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
It was observed that the current implementation of of get_proc_addr()
fails to load the kernel32.dll with code ERROR_INVALID_PARAMETER.
Probably the reason is that kernel32.dll is already loaded. The
behavior was seen at Windows SP1, both 32bit and 64bit. Probably it
would behave same way in some or all other Windows versions.
This breaks all usages of "clone --local", including the automatic
tests where they call it.
The function CreateHardLink is available in all supported Windows
versions (since Windows XP), so there is no more need to resolve it
in runtime.
Signed-off-by: Max Kirillov <max@max630.net>
We have this loop where we try to remove the read-only attribute when
rename() fails and try again. If it fails again, let's not try to remove
the read-only attribute and try *again*.
This fixes https://github.com/git-for-windows/git/issues/1299
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Toolset v120 corresponds to Visual Studio 2013. We already used
dependencies that were hardcoded to v140 (i.e. Visual Studio 2015), so
let's just remove the cruft.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Teach the top-level git Makefile to use whatever VS compiler
tool chain is installed on the system.
When building git from the command line in a git-sdk BASH
window with MAKE, the shell environment has environment
variables for GCC tools, but not MSVC tools. MSVC bindings
are only avaliable from the various "VcVarsAll.bat" scripts
run by the "Developer Command Prompt" shortcuts.
Add compat/vcbuild/find_vs_env.bat to the Makefile. It
uses the various "VcVarsAll.bat" scripts in a background
Developer Command Prompt process to compute the proper
environment variables and publish them for use by the Makefile.
[jes: fixed typos, used %SystemRoot% instead of C:\WINDOWS]
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Dependencies such as cURL and OpenSSL are necessary to build and run
Git. Previously, we obtained those dependencies by fetching NuGet
packages.
However, it is notoriously hard to keep NuGet packages of C/C++
libraries up-to-date, as the toolsets for different Visual Studio
versions are different, and the NuGet packages would have to ship them
all.
That is the reason why the NuGet packages we use are quite old, and even
insecure in the case of cURL and OpenSSL (the versions contain known
security flaws that have been addressed by later versions for which no
NuGet packages are available).
The better way to handle this situation is to use the vcpkg system:
https://github.com/Microsoft/vcpkg
The idea is that a single Git repository contains enough supporting
files to build up-to-date versions of a large number of Open Source
libraries on demand, including cURL and OpenSSL.
We integrate this system via four new .bat files to
1) initialize the vcpkg system,
2) build the packages,
4) set up Git's Makefile system to find the build artifacts, and
3) copy the artifacts into the top-level directory
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Install required third-party DLLs next to EXEs.
Build and install release mode PDBs for git
executables allowing detailed stack traces
in the event of crash.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
The MINGW version of the main() wrapper gets away with declaring symbols
that were intentionally not exported. However, some of these symbols do
not actually exist in MSVC's UCRT.
So let's add an MSVC version of the main() wrapper that uses wmain() and
imports the UNICODE argv and environment. While at it, we pass our UTF-8
version of ARGV to the real main -- rather than overwriting __argv as is
done in the MINGW Version.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
This special-cases various signals that are not supported on Windows,
such as SIGPIPE. These cause the UCRT to throw asserts (at least in
debug mode).
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
This adds MSVC versions of getenv() and friends. These take UTF-8
arguments and return UTF-8 values, but use the UNICODE versions
of the CRT routines. This avoids the need to write to __environ
(which is only visible if you statically link to the CRT). This
also avoids the CP_ACP conversions performed inside the CRT.
It also avoids various memory leaks and problems.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
GCC and MSVC disagree about using the GCC extension _ANONYMOUS_UNION.
Simply skip that offending keyword when compiling with MSVC.
Signed-off-by: Philip Oakley <philipoakley@iee.org>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This constant is not defined in MSVC's headers.
In UCRT's fcntl.h, _O_RDONLY, _O_WRONLY and _O_RDWR are defined as 0, 1
and 2, respectively. Yes, that means that UCRT breaks with the tradition
that O_RDWR == O_RDONLY | O_WRONLY.
It is a perfectly legal way to define those constants, though, therefore
we need to take care of defining O_ACCMODE accordingly.
This is particularly important in order to keep our "open() can set
errno to EISDIR" emulation working: it tests that (flags & O_ACCMODE) is
not identical to O_RDONLY before going on to test specifically whether
the file for which open() reported EACCES is, in fact, a directory.
Signed-off-by: Philip Oakley <philipoakley@iee.org>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Support -Z flags ("specify PDB options"), only include -l args on link
commands, and force PDBs to be created.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
This commit contains a GNU Makefile and NuGet configuration scripts to
download and install the various third-party libraries that we will need
to build/link with when using VS2015 to build Git.
The file "compat/vcbuild/README_VS2015.txt" contains instructions for
using this.
In this commit, "compat/vcbuild/Makefile" contains hard-coded version
numbers of the packages we require. These are set to the current
versions as of the time of this commit. We use "nuget restore" to
install them explicitly using a "package.config". A future improvement
would try to use some of the automatic package management functions and
eliminate the need to specify exact versions. I tried, but could not
get this to work. NuGet was happy dowload "minimum requirements" rather
than "lastest" for dependencies -- and only look at one package at a
time. For example, both curl and openssl depend upon zlib and have
different minimums. It was unclear which version of zlib would be
installed and seemed to be dependent on the order of the top-level
packages. So, I'm skipping that for now.
We need to be very precise when specifying NuGet package versions: while
nuget.exe auto-completes a version, say, 1.0.2 to 1.0.2.0, we will want
to parse packages.config ourselves, to generate the Visual Studio
solution, and there we need the exact version number to be able to
generate the exact path to the correct .targets file.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
We no longer use any of MSVCRT's stat-functions, so there's no need to
stick to a CRT-compatible 'struct stat' either.
Define and use our own POSIX-2013-compatible 'struct stat' with nanosecond-
precision file times.
Note: Due to performance issues when using git variants with different file
time resolutions, this patch does *not* yet enable nanosecond precision in
the Makefile (use 'make USE_NSEC=1').
Signed-off-by: Karsten Blees <blees@dcon.de>
fstat() is the only stat-related CRT function for which we don't have a
full replacement yet (and thus the only reason to stick with MSVCRT's
'struct stat' definition).
Fully implement fstat(), in preparation of implementing a POSIX 2013
compatible 'struct stat' with nanosecond-precision file times.
Signed-off-by: Karsten Blees <blees@dcon.de>
The contract for the stat() and lstat() function is:
> stat(): stats the file pointed to by path and fills in buf.
> lstat(): is identical to stat(), except that if path is a symbolic link,
> then the link itself is stat-ed, not the file that it refers to.
stat() should always return the statistics of the file or directory a
symbolic link is pointing to. The lstat() function is used to get the
stats for the symlink. Hence the check should not be there.
Signed-off-by: Loris Chiocca <loris@chiocca.ch>
This is needed so that `_wchdir()` can be used with drive root
directories, e.g. C:\ (`_wchdir("C:")` fails to switch the directory
to the root directory).
This fixes https://github.com/msysgit/git/issues/359 (in Git for Windows
2.x only, though).
Likewise, `readlink()`'s semantics require a trailing slash for symbolic
links pointing to directories. Otherwise all checked out symbolic links
pointing to directories would be marked as modified even directly after a
fresh clone.
This fixes https://github.com/git-for-windows/git/issues/210
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Symlinks on Windows have a flag that indicates whether the target is a file
or a directory. Symlinks of wrong type simply don't work. This even affects
core Win32 APIs (e.g. DeleteFile() refuses to delete directory symlinks).
However, CreateFile() with FILE_FLAG_BACKUP_SEMANTICS doesn't seem to care.
Check the target type by first creating a tentative file symlink, opening
it, and checking the type of the resulting handle. If it is a directory,
recreate the symlink with the directory flag set.
It is possible to create symlinks before the target exists (or in case of
symlinks to symlinks: before the target type is known). If this happens,
create a tentative file symlink and postpone the directory decision: keep
a list of phantom symlinks to be processed whenever a new directory is
created in mingw_mkdir().
Limitations: This algorithm may fail if a link target changes from file to
directory or vice versa, or if the target directory is created in another
process.
Signed-off-by: Karsten Blees <blees@dcon.de>
Implement symlink() that always creates file symlinks. Fails with ENOSYS
if symlinks are disabled or unsupported.
Note: CreateSymbolicLinkW() was introduced with symlink support in Windows
Vista. For compatibility with Windows XP, we need to load it dynamically
and fail gracefully if it isnt's available.
Signed-off-by: Karsten Blees <blees@dcon.de>
Implement readlink() by reading NTFS reparse points. Works for symlinks
and directory junctions. If symlinks are disabled, fail with ENOSYS.
Signed-off-by: Karsten Blees <blees@dcon.de>
If symlinks are enabled, resolve all symlinks when changing directories,
as required by POSIX.
Note: Git's real_path() function bases its link resolution algorithm on
this property of chdir(). Unfortunately, the current directory on Windows
is limited to only MAX_PATH (260) characters. Therefore using symlinks and
long paths in combination may be problematic.
Note: GetFinalPathNameByHandleW() was introduced with symlink support in
Windows Vista. Thus, for compatibility with Windows XP, we need to load it
dynamically and behave gracefully if it isnt's available.
Signed-off-by: Karsten Blees <blees@dcon.de>
MSVCRT's _wrename() cannot rename symlinks over existing files: it returns
success without doing anything. Newer MSVCR*.dll versions probably do not
have this problem: according to CRT sources, they just call MoveFileEx()
with the MOVEFILE_COPY_ALLOWED flag.
Get rid of _wrename() and call MoveFileEx() with proper error handling.
Signed-off-by: Karsten Blees <blees@dcon.de>
_wunlink() / DeleteFileW() refuses to delete symlinks to directories. If
_wunlink() fails with ERROR_ACCESS_DENIED, try _wrmdir() as well.
Signed-off-by: Karsten Blees <blees@dcon.de>
BusyBox comes with a ton of applets ("applet" being the identical
concept to Git's "builtins"). And similar to Git's builtins, the applets
can be called via `busybox <command>`, or the BusyBox executable can be
copied/hard-linked to the command name.
The similarities do not end here. Just as with Git's builtins, it is
problematic that BusyBox' hard-linked applets cannot easily be put into
a .zip file: .zip archives have no concept of hard-links and therefore
would store identical copies (and also extract identical copies,
"inflating" the archive unnecessarily).
To counteract that issue, MinGit already ships without hard-linked
copies of the builtins, and the plan is to do the same with BusyBox'
applets: simply ship busybox.exe as single executable, without
hard-linked applets.
To accommodate that, Git is being taught by this commit a very special
trick, exploiting the fact that it is possible to call an executable
with a command-line whose argv[0] is different from the executable's
name: when `sh` is to be spawned, and no `sh` is found in the PATH, but
busybox.exe is, use that executable (with unchanged argv).
Likewise, if any executable to be spawned is not on the PATH, but
busybox.exe is found, parse the output of `busybox.exe --help` to find
out what applets are included, and if the command matches an included
applet name, use busybox.exe to execute it.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The main idea of this patch is that even if we have to look up the
absolute path of the script, if only the basename was specified as
argv[0], then we should use that basename on the command line, too, not
the absolute path.
This patch will also help with the upcoming patch where we automatically
substitute "sh ..." by "busybox sh ..." if "sh" is not in the PATH but
"busybox" is: we will do that by substituting the actual executable, but
still keep prepending "sh" to the command line.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Symlinks on Windows don't work the same way as on Unix systems. E.g. there
are different types of symlinks for directories and files, creating
symlinks requires administrative privileges etc.
By default, disable symlink support on Windows. I.e. users explicitly have
to enable it with 'git config [--system|--global] core.symlinks true'.
The test suite ignores system / global config files. Allow testing *with*
symlink support by checking if native symlinks are enabled in MSys2 (via
'MSYS=winsymlinks:nativestrict').
Reminder: This would need to be changed if / when we find a way to run the
test suite in a non-MSys-based shell (e.g. dash).
Signed-off-by: Karsten Blees <blees@dcon.de>
The retry pattern is duplicated in three places. It also seems to be too
hard to use: mingw_unlink() and mingw_rmdir() duplicate the code to retry,
and both of them do so incompletely. They also do not restore errno if the
user answers 'no'.
Introduce a retry_ask_yes_no() helper function that handles retry with
small delay, asking the user, and restoring errno.
mingw_unlink: include _wchmod in the retry loop (which may fail if the
file is locked exclusively).
mingw_rmdir: include special error handling in the retry loop.
Signed-off-by: Karsten Blees <blees@dcon.de>
