Commit Graph

512 Commits

Author SHA1 Message Date
Nico Weber 41597b92b1 Revert 332750, llvm part (see comment on D46910).
llvm-svn: 332823
2018-05-20 23:03:17 +00:00
Petr Hosek 24b61ac832 [Support] Avoid normalization in sys::getDefaultTargetTriple
The return value of sys::getDefaultTargetTriple, which is derived from
-DLLVM_DEFAULT_TRIPLE, is used to construct tool names, default target,
and in the future also to control the search path directly; as such it
should be used textually, without interpretation by LLVM.

Normalization of this value may lead to unexpected results, for example
if we configure LLVM with -DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-linux-gnu,
normalization will transform that value to x86_64--linux-gnu. Driver will
use that value to search for tools prefixed with x86_64--linux-gnu- which
may be confusing. This is also inconsistent with the behavior of the
--target flag which is taken as-is without any normalization and overrides
the value of LLVM_DEFAULT_TARGET_TRIPLE.

Users of sys::getDefaultTargetTriple already perform their own
normalization as needed, so this change shouldn't impact existing logic.

Differential Revision: https://reviews.llvm.org/D46910

llvm-svn: 332750
2018-05-18 18:33:07 +00:00
JF Bastien aa1333a91f Signal handling should be signal-safe
Summary:
Before this patch, signal handling wasn't signal safe. This leads to real-world
crashes. It used ManagedStatic inside of signals, this can allocate and can lead
to unexpected state when a signal occurs during llvm_shutdown (because
llvm_shutdown destroys the ManagedStatic). It also used cl::opt without custom
backing storage. Some de-allocation was performed as well. Acquiring a lock in a
signal handler is also a great way to deadlock.

We can't just disable signals on llvm_shutdown because the signals might do
useful work during that shutdown. We also can't just disable llvm_shutdown for
programs (instead of library uses of clang) because we'd have to then mark the
pointers as not leaked and make sure all the ManagedStatic uses are OK to leak
and remain so.

Move all of the code to lock-free datastructures instead, and avoid having any
of them in an inconsistent state. I'm not trying to be fancy, I'm not using any
explicit memory order because this code isn't hot. The only purpose of the
atomics is to guarantee that a signal firing on the same or a different thread
doesn't see an inconsistent state and crash. In some cases we might miss some
state (for example, we might fail to delete a temporary file), but that's fine.

Note that I haven't touched any of the backtrace support despite it not
technically being totally signal-safe. When that code is called we know
something bad is up and we don't expect to continue execution, so calling
something that e.g. sets errno is the least of our problems.

A similar patch should be applied to lib/Support/Windows/Signals.inc, but that
can be done separately.

Fix r332428 which I reverted in r332429. I originally used double-wide CAS
because I was lazy, but some platforms use a runtime function for that which
thankfully failed to link (it would have been bad for signal handlers
otherwise). I use a separate flag to guard the data instead.

<rdar://problem/28010281>

Reviewers: dexonsmith

Subscribers: steven_wu, llvm-commits
llvm-svn: 332496
2018-05-16 17:25:35 +00:00
JF Bastien b8931c1cf4 Revert "Signal handling should be signal-safe"
Some bots don't have double-pointer width compare-and-exchange. Revert for now.q

llvm-svn: 332429
2018-05-16 04:36:37 +00:00
JF Bastien 253aa8b099 Signal handling should be signal-safe
Summary:
Before this patch, signal handling wasn't signal safe. This leads to real-world
crashes. It used ManagedStatic inside of signals, this can allocate and can lead
to unexpected state when a signal occurs during llvm_shutdown (because
llvm_shutdown destroys the ManagedStatic). It also used cl::opt without custom
backing storage. Some de-allocation was performed as well. Acquiring a lock in a
signal handler is also a great way to deadlock.

We can't just disable signals on llvm_shutdown because the signals might do
useful work during that shutdown. We also can't just disable llvm_shutdown for
programs (instead of library uses of clang) because we'd have to then mark the
pointers as not leaked and make sure all the ManagedStatic uses are OK to leak
and remain so.

Move all of the code to lock-free datastructures instead, and avoid having any
of them in an inconsistent state. I'm not trying to be fancy, I'm not using any
explicit memory order because this code isn't hot. The only purpose of the
atomics is to guarantee that a signal firing on the same or a different thread
doesn't see an inconsistent state and crash. In some cases we might miss some
state (for example, we might fail to delete a temporary file), but that's fine.

Note that I haven't touched any of the backtrace support despite it not
technically being totally signal-safe. When that code is called we know
something bad is up and we don't expect to continue execution, so calling
something that e.g. sets errno is the least of our problems.

A similar patch should be applied to lib/Support/Windows/Signals.inc, but that
can be done separately.

<rdar://problem/28010281>

Reviewers: dexonsmith

Subscribers: aheejin, llvm-commits

Differential Revision: https://reviews.llvm.org/D46858

llvm-svn: 332428
2018-05-16 04:30:00 +00:00
JF Bastien 93bce5108b [NFC] Update comments
Don't prepend function or data name before each comment. Split into its own NFC patch as requested in D46858.

llvm-svn: 332323
2018-05-15 04:06:28 +00:00
Brian Gesiak 82de4e6b93 [Support] Add docs for 'openFileFor{Write,Read}'
Summary:
Add documentation for the LLVM Support functions `openFileForWrite` and
`openFileForRead`. The `openFileForRead` parameter `RealPath`, in
particular, I think warranted some explanation.

In addition, make the behavior of the functions more consistent across
platforms. Prior to this patch, Windows would set or not set the result
file descriptor based on the nature of the error, whereas Unix would
consistently set it to `-1` if the open failed. Make Windows
consistently set it to `-1` as well.

Test Plan:
1. `ninja check-llvm`
2. `ninja docs-llvm-html`

Reviewers: zturner, rnk, danielmartin, scanon

Reviewed By: danielmartin, scanon

Subscribers: scanon, danielmartin, llvm-commits

Differential Revision: https://reviews.llvm.org/D46499

llvm-svn: 332075
2018-05-11 01:47:27 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Aaron Smith 02caafd7e5 [support] Revert the changes made to Path.inc for the default Windows code page
Path.inc/widenPath tries to decode the path using both UTF-8 and the default Windows code page.
This is no longer necessary with the new InitLLVM method which ensures that the command line
arguemnts are already UTF-8 on Windows.
 

llvm-svn: 330266
2018-04-18 15:26:26 +00:00
Rui Ueyama e6ac9f5ec3 Rename sys::Process::GetArgumentVector -> sys::windows::GetCommandLineArguments
GetArgumentVector (or GetCommandLineArguments) is very Windows-specific.
I think it doesn't make much sense to provide that function from sys::Process.

I also made a change so that the function takes a BumpPtrAllocator
instead of a SpecificBumpPtrAllocator. The latter is the class to call
dtors, but since char * is trivially destructible, we should use the
former class.

Differential Revision: https://reviews.llvm.org/D45641

llvm-svn: 330216
2018-04-17 21:09:16 +00:00
Martin Storsjo 8293161712 [Support] Fix building for Windows on ARM
The commit in SVN r310001 that added support for this actually didn't
use the right struct field for the frame pointer - for ARM, there is
no register named Fp in the CONTEXT struct. On Windows, the R11
register is used as frame pointer.

Differential Revision: https://reviews.llvm.org/D45590

llvm-svn: 329991
2018-04-13 06:38:02 +00:00
Aaron Smith 8a5ea61886 Windows needs the current codepage instead of utf8 sometimes
Llvm-mc (and tools that use Path.inc on Windows) assume that strings are utf-8 
encoded, however, this is not always the case. On Windows the default codepage 
is not utf-8, so most of the time the strings are not utf-8 encoded.

The lld test 'format-binary-non-ascii' uses llvm-mc with a file with non-ascii 
characters in the name which is how this bug was found. The test fails when run 
using Python 3 because it uses properly encoded unicode strings (Python 2 actually 
ends up using a byte string which is not utf-8 encoded, so the test passes, but 
that's separate issue). 

Patch by Stella Stamenova!

llvm-svn: 329468
2018-04-07 00:32:59 +00:00
Nico Weber 868112181b Remove HAVE_LIBPSAPI, HAVE_SHELL32.
These used to be set in the old autoconf build, but the cmake build has had a
"TODO: actually check for these" comment since it was checked in, and they
were set to 1 on mingw unconditionally.  It seems safe to say that they always
exist under mingw, so just remove them and assume they're set exactly when on
mingw (with msvc, we use `pragma comment` instead of linking these via flags).

llvm-svn: 328992
2018-04-02 17:32:48 +00:00
Zachary Turner adad33011f [Support] Add WriteThroughMemoryBuffer.
This is like MemoryBuffer (read-only) and WritableMemoryBuffer
(writable private), but where the underlying file can be modified
after writing.  This is useful when you want to open a file, make
some targeted edits, and then write it back out.

Differential Revision: https://reviews.llvm.org/D44230

llvm-svn: 327057
2018-03-08 20:34:47 +00:00
Serge Pavlov 76d8ccee2e Report fatal error in the case of out of memory
This is the second part of recommit of r325224. The previous part was
committed in r325426, which deals with C++ memory allocation. Solution
for C memory allocation involved functions `llvm::malloc` and similar.
This was a fragile solution because it caused ambiguity errors in some
cases. In this commit the new functions have names like `llvm::safe_malloc`.

The relevant part of original comment is below, updated for new function
names.

Analysis of fails in the case of out of memory errors can be tricky on
Windows. Such error emerges at the point where memory allocation function
fails, but manifests itself when null pointer is used. These two points
may be distant from each other. Besides, next runs may not exhibit
allocation error.

In some cases memory is allocated by a call to some of C allocation
functions, malloc, calloc and realloc. They are used for interoperability
with C code, when allocated object has variable size and when it is
necessary to avoid call of constructors. In many calls the result is not
checked for null pointer. To simplify checks, new functions are defined
in the namespace 'llvm': `safe_malloc`, `safe_calloc` and `safe_realloc`.
They behave as corresponding standard functions but produce fatal error if
allocation fails. This change replaces the standard functions like 'malloc'
in the cases when the result of the allocation function is not checked
for null pointer.

Finally, there are plain C code, that uses malloc and similar functions. If
the result is not checked, assert statement is added.

Differential Revision: https://reviews.llvm.org/D43010

llvm-svn: 325551
2018-02-20 05:41:26 +00:00
Zachary Turner acd8791c26 Call FlushFileBuffers on output files.
There is a latent Windows kernel bug, the exact trigger
conditions are not well understood, which can cause a file
to be correctly written, but unable to be correctly read.

The workaround appears to be simply calling FlushFileBuffers.

Differential Revision: https://reviews.llvm.org/D42925

llvm-svn: 325274
2018-02-15 18:36:10 +00:00
Serge Pavlov 4500001905 Revert r325224 "Report fatal error in the case of out of memory"
It caused fails on some buildbots.

llvm-svn: 325227
2018-02-15 09:45:59 +00:00
Serge Pavlov 431502a675 Report fatal error in the case of out of memory
Analysis of fails in the case of out of memory errors can be tricky on
Windows. Such error emerges at the point where memory allocation function
fails, but manifests itself when null pointer is used. These two points
may be distant from each other. Besides, next runs may not exhibit
allocation error.

Usual programming practice does not require checking result of 'operator
new' because it throws 'std::bad_alloc' in the case of allocation error.
However, LLVM is usually built with exceptions turned off, so 'new' can
return null pointer. This change installs custom new handler, which causes
fatal error in the case of out of memory. The handler is installed
automatically prior to call to 'main' during construction of a static
object defined in 'lib/Support/ErrorHandling.cpp'. If the application does
not use this file, the handler may be installed manually by a call to
'llvm::install_out_of_memory_new_handler', declared in
'include/llvm/Support/ErrorHandling.h".

There are calls to C allocation functions, malloc, calloc and realloc.
They are used for interoperability with C code, when allocated object has
variable size and when it is necessary to avoid call of constructors. In
many calls the result is not checked against null pointer. To simplify
checks, new functions are defined in the namespace 'llvm' with the
same names as these C function. These functions produce fatal error if
allocation fails. User should use 'llvm::malloc' instead of 'std::malloc'
in order to use the safe variant. This change replaces 'std::malloc'
in the cases when the result of allocation function is not checked against
null pointer.

Finally, there are plain C code, that uses malloc and similar functions. If
the result is not checked, assert statements are added.

Differential Revision: https://reviews.llvm.org/D43010

llvm-svn: 325224
2018-02-15 09:20:26 +00:00
Eric Christopher 668e6b4b05 Typo fix SIBABRT -> SIGABRT.
Based on a patch by Henry Wong!

llvm-svn: 322902
2018-01-18 21:45:51 +00:00
Rafael Espindola 20569e96e9 Delete temp file if rename fails.
Without this when lld failed to replace the output file it would leave
the temporary behind. The problem is that the existing logic is

- cancel the delete flag
- rename

We have to cancel first to avoid renaming and then crashing and
deleting the old version. What is missing then is deleting the
temporary file if the rename fails.

This can be an issue on both unix and windows, but I am not sure how
to cause the rename to fail reliably on unix. I think it can be done
on ZFS since it has an ACL system similar to what windows uses, but
adding support for checking that in llvm-lit is probably not worth it.

llvm-svn: 319786
2017-12-05 16:40:56 +00:00
Rafael Espindola 3ecd20430c Use FILE_FLAG_DELETE_ON_CLOSE for TempFile on windows.
We won't see the temp file no more.

llvm-svn: 319137
2017-11-28 01:41:22 +00:00
Rafael Espindola bce112c9e9 Add an F_Delete flag.
For now this only changes the handle Access.

llvm-svn: 319121
2017-11-28 00:12:44 +00:00
Rafael Espindola 811d5e86a2 move static function. NFC
llvm-svn: 318729
2017-11-21 05:35:45 +00:00
Rafael Espindola 5908affee9 Split a rename_handle out of rename on windows.
llvm-svn: 318725
2017-11-21 01:52:44 +00:00
Rafael Espindola 8dc0e1095f Reorder static functions. NFC.
llvm-svn: 318584
2017-11-18 02:12:53 +00:00
Rafael Espindola 041299e3eb Split realPathFromHandle in two.
By having an UTF-16 version we avoid some code duplication in calling
GetFinalPathNameByHandleW.

llvm-svn: 318583
2017-11-18 02:05:59 +00:00
Lang Hames afcb70d031 [Support] Support NetBSD PaX MPROTECT in sys::Memory.
Removes AllocateRWX, setWritable and setExecutable from sys::Memory and
standardizes on allocateMappedMemory / protectMappedMemory. The
allocateMappedMemory method is updated to request full permissions for memory
blocks so that they can be marked executable later.

llvm-svn: 318464
2017-11-16 23:04:44 +00:00
Zachary Turner ab1ade496c Fix some undefined beahvior in FileMapping.
This was broken when building a 32-bit native toolchain, as
shifting a size_t right by 32 is UB when sizeof(size_t) == 8.

llvm-svn: 318462
2017-11-16 22:39:55 +00:00
Bob Haarman c6bb9380e0 [support] allocate exact size required for mapping in Support/Windws/Path.inc
Summary:
zturner suggested that mapped_file_region::init() on Windows seems to
create mappings that are larger than they need to be: Offset+Size
instead of Size. Indeed, that appears to be the case. I confirmed that
tests pass with mappings of just Size bytes, and fail with Size-1
bytes, suggesting that Size is indeed the correct value.

Reviewers: amccarth, zturner

Reviewed By: zturner

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D39876

llvm-svn: 317850
2017-11-10 00:17:31 +00:00
Bob Haarman d4e75f84e5 [support] remove tautological comparison in Support/Windows/Path.inc
Summary:
The removed code checks that we are able to handle a 64-bit number, but
the code we're calling takes two dwords (for a total of 64 bits), so this
is always true.

Reviewers: zturner, rnk, majnemer, compnerd

Reviewed By: zturner

Subscribers: amccarth, hiraditya, lebedev.ri, llvm-commits

Differential Revision: https://reviews.llvm.org/D39263

llvm-svn: 316814
2017-10-27 23:41:17 +00:00
Hans Wennborg 477c974bc8 Work around lack of Wine support for SetFileInformationByHandle harder
In r315079 I added a check for the ERROR_CALL_NOT_IMPLEMENTED error
code, but it turns out earlier versions of Wine just returned false
without setting any error code.

This patch handles the unset error code case.

llvm-svn: 315597
2017-10-12 17:38:22 +00:00
Hans Wennborg 17701ab5bd Support: Work around missing SetFileInformationByHandle on Wine
In r315079, fs::rename was reimplemented in terms of CreateFile and
SetFileInformationByHandle. Unfortunately, the latter isn't supported by
Wine. This adds a fallback to MoveFileEx for that case.

Differential Revision: https://reviews.llvm.org/D38817

llvm-svn: 315520
2017-10-11 22:04:14 +00:00
Peter Collingbourne b4f1b88551 WIN32_FIND_DATA -> WIN32_FIND_DATAW.
Should fix mingw bot.

llvm-svn: 315413
2017-10-11 02:09:06 +00:00
Peter Collingbourne 0dfdb44797 Support: Have directory_iterator::status() return FindFirstFileEx/FindNextFile results on Windows.
This allows clients to avoid an unnecessary fs::status() call on each
directory entry. Because the information returned by FindFirstFileEx
is a subset of the information returned by a regular status() call,
I needed to extract a base class from file_status that contains only
that information.

On my machine, this reduces the time required to enumerate a ThinLTO
cache directory containing 520k files from almost 4 minutes to less
than 2 seconds.

Differential Revision: https://reviews.llvm.org/D38716

llvm-svn: 315378
2017-10-10 22:19:46 +00:00
Peter Collingbourne 0f9e889881 Support: On Windows, use CreateFileW to delete files in sys::fs::remove().
This saves a call to stat().

Differential Revision: https://reviews.llvm.org/D38715

llvm-svn: 315351
2017-10-10 19:39:46 +00:00
Adrian McCarthy e6275c6edb Fix after r315079
Microsoft's debug implementation of std::copy checks if the destination is an
array and then does some bounds checking.  This was causing an assertion
failure in fs::rename_internal which copies to a buffer of the appropriate
size but that's type-punned to an array of length 1 for API compatibility
reasons.

Fix is to make make the destination a pointer rather than an array.

llvm-svn: 315222
2017-10-09 17:50:01 +00:00
Peter Collingbourne 80e31f1f84 Support: Rewrite Windows implementation of sys::fs::rename to be more POSIXy.
The current implementation of rename uses ReplaceFile if the
destination file already exists. According to the documentation for
ReplaceFile, the source file is opened without a sharing mode. This
means that there is a short interval of time between when ReplaceFile
renames the file and when it closes the file during which the
destination file cannot be opened.

This behaviour is not POSIX compliant because rename is supposed
to be atomic. It was also causing intermittent link failures when
linking with a ThinLTO cache; the ThinLTO cache implementation expects
all cache files to be openable.

This patch addresses that problem by re-implementing rename
using CreateFile and SetFileInformationByHandle. It is roughly a
reimplementation of ReplaceFile with a better sharing policy as well
as support for renaming in the case where the destination file does
not exist.

This implementation is still not fully POSIX. Specifically in the case
where the destination file is open at the point when rename is called,
there will be a short interval of time during which the destination
file will not exist. It isn't clear whether it is possible to avoid
this using the Windows API.

Differential Revision: https://reviews.llvm.org/D38570

llvm-svn: 315079
2017-10-06 17:14:36 +00:00
Roman Lebedev 1e053ab09a [support] mapped_file_region: and fix the windows code too
Followup for r314312 / r314313
Sorry, i really failed to fully grep all the codebase :/

llvm-svn: 314321
2017-09-27 17:24:34 +00:00
Alexander Kornienko 208eecd57f Convenience/safety fix for llvm::sys::Execute(And|No)Wait
Summary:
Change the type of the Redirects parameter of llvm::sys::ExecuteAndWait,
ExecuteNoWait and other APIs that wrap them from `const StringRef **` to
`ArrayRef<Optional<StringRef>>`, which is safer and simplifies the use of these
APIs (no more local StringRef variables just to get a pointer to).

Corresponding clang changes will be posted as a separate patch.

Reviewers: bkramer

Reviewed By: bkramer

Subscribers: vsk, llvm-commits

Differential Revision: https://reviews.llvm.org/D37563

llvm-svn: 313155
2017-09-13 17:03:37 +00:00
Alexander Kornienko 3ad84ee009 Minor style fixes in lib/Support/**/Program.(inc|cpp).
No functional changes intended.

llvm-svn: 312646
2017-09-06 16:28:33 +00:00
NAKAMURA Takumi a1e97a77f5 Untabify.
llvm-svn: 311875
2017-08-28 06:47:47 +00:00
Pirama Arumuga Nainar 3d48bb5fc2 [Support, Windows] Handle long paths with unix separators
Summary:
The function widenPath() for Windows also normalizes long path names by
iterating over the path's components and calling append().  The
assumption during the iteration that separators are not returned by the
iterator doesn't hold because the iterators do return a separator when
the path has a drive name.  Handle this case by ignoring separators
during iteration.

Reviewers: rnk

Subscribers: danalbert, srhines

Differential Revision: https://reviews.llvm.org/D36752

llvm-svn: 311382
2017-08-21 20:49:44 +00:00
Ben Dunbobbin ac6a5aab45 [Support] env vars with empty values on windows
An environment variable can be in one of three states:

1. undefined.
2. defined with a non-empty value.
3. defined but with an empty value.

The windows implementation did not support case 3
(it was not handling errors). The Linux implementation
is already correct.

Differential Revision: https://reviews.llvm.org/D36394

llvm-svn: 311174
2017-08-18 16:55:44 +00:00
Reid Kleckner cefb333582 [Support] Use FILE_SHARE_DELETE to fix RemoveFileOnSignal on Windows
Summary:
Tools like clang that use RemoveFileOnSignal on their output files
weren't actually able to clean up their outputs before this change.  Now
the call to llvm::sys::fs::remove succeeds and the temporary file is
deleted. This is a stop-gap to fix clang before implementing the
solution outlined in PR34070.

Reviewers: davide

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D36337

llvm-svn: 310137
2017-08-04 21:52:00 +00:00
Reid Kleckner af3e93ac93 [Support] Remove getPathFromOpenFD, it was unused
Summary:
It was added to support clang warnings about includes with case
mismatches, but it ended up not being necessary.

Reviewers: twoh, rafael

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D36328

llvm-svn: 310078
2017-08-04 17:43:49 +00:00
Martell Malone 346a5fdc9b Support: WOA64 and WOA Signals
Reviewers: rnk

Differential Revision: https://reviews.llvm.org/D21813

llvm-svn: 310001
2017-08-03 23:12:33 +00:00
Frederich Munch 5fdd2cbae8 Allow clients to specify search order of DynamicLibraries.
Summary: Different JITs and other clients of LLVM may have different needs in how symbol resolution should occur.

Reviewers: v.g.vassilev, lhames, karies

Reviewed By: v.g.vassilev

Subscribers: pcanal, llvm-commits

Differential Revision: https://reviews.llvm.org/D33529

llvm-svn: 307849
2017-07-12 21:22:45 +00:00
Alex Lorenz 215be39cab Update the Windows version of updateTripleOSVersion to account for
changes in r307372

llvm-svn: 307377
2017-07-07 10:08:52 +00:00
Alex Lorenz 3803df3dcd [Support] sys::getProcessTriple should return a macOS triple using
the system's version of macOS

sys::getProcessTriple returns LLVM_HOST_TRIPLE, whose system version might not
be the actual version of the system on which the compiler running. This commit
ensures that, for macOS, sys::getProcessTriple returns a triple with the
system's macOS version.

rdar://33177551

Differential Revision: https://reviews.llvm.org/D34446

llvm-svn: 307372
2017-07-07 09:53:47 +00:00
NAKAMURA Takumi fc7f3b7514 [CMake] Introduce LLVM_TARGET_TRIPLE_ENV as an option to override LLVM_DEFAULT_TARGET_TRIPLE at runtime.
No behavior is changed if LLVM_TARGET_TRIPLE_ENV is blank or undefined.

If LLVM_TARGET_TRIPLE_ENV is "TEST_TARGET_TRIPLE" and $TEST_TARGET_TRIPLE is not blank,
llvm::sys::getDefaultTargetTriple() returns $TEST_TARGET_TRIPLE.
Lit resets config.target_triple and config.environment[LLVM_TARGET_TRIPLE_ENV] to change the default target.

Without changing LLVM_DEFAULT_TARGET_TRIPLE nor rebuilding, lit can be run;

  TEST_TARGET_TRIPLE=i686-pc-win32 bin/llvm-lit -sv path/to/test/
  TEST_TARGET_TRIPLE=i686-pc-win32 ninja check-clang-tools

Differential Revision: https://reviews.llvm.org/D33662

llvm-svn: 305632
2017-06-17 03:19:08 +00:00