Commit Graph

4675 Commits

Author SHA1 Message Date
Igor Kudrin a38432cefb [CommandLine] Allow grouping options which can have values.
This patch allows all forms of values for options to be used at the end
of a group. With the fix, it is possible to follow the way GNU binutils
tools handle grouping options better. For example, the -j option can be
used with objdump in any of the following ways:

$ objdump -d -j .text a.o
$ objdump -d -j.text a.o
$ objdump -dj .text a.o
$ objdump -dj.text a.o

Differential Revision: https://reviews.llvm.org/D58711

llvm-svn: 355185
2019-03-01 09:22:42 +00:00
Igor Kudrin 875f05828d [CommandLine] Do not crash if an option has both ValueRequired and Grouping.
If an option, which requires a value, has a `cl::Grouping` formatting
modifier, it works well as far as it is used at the end of a group,
or as a separate argument. However, if the option appears accidentally
in the middle of a group, the program just crashes. This patch prints
an error message instead.

Differential Revision: https://reviews.llvm.org/D58499

llvm-svn: 355184
2019-03-01 09:20:56 +00:00
Alexandre Ganea 14d58f5986 Fix SupportTests.exe/AllocationTests/MappedMemoryTest.AllocAndReleaseHuge when the machine doesn't have large pages enabled.
llvm-svn: 355067
2019-02-28 03:42:07 +00:00
Alexandre Ganea 68c4827660 Fix non-Windows platforms build break introduced by r355065. Fixes:
In file included from /home/buildbots/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm/lib/Support/Memory.cpp:14:
/home/buildbots/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm/include/llvm/Support/Memory.h:38:14: error: private field 'Flags' is not used [-Werror,-Wunused-private-field]
    unsigned Flags = 0;
             ^
1 error generated.

llvm-svn: 355066
2019-02-28 03:03:07 +00:00
Alexandre Ganea b05ba93578 [Memory] Add basic support for large/huge memory pages
This patch introduces Memory::MF_HUGE_HINT which indicates that allocateMappedMemory() shall return a pointer to a large memory page.
However the flag is a hint because we're not guaranteed in any way that we will get back a large memory page. There are several restrictions:

- Large/huge memory pages aren't enabled by default on modern OSes (Windows 10 and Linux at least), and should be manually enabled/reserved.
- Once enabled, it should be kept in mind that large pages are physical only, they can't be swapped.
- Memory fragmentation can affect the availability of large pages, especially after running the OS for a long time and/or running along many other applications.

Memory::allocateMappedMemory() will fallback to 4KB pages if it can't allocate 2MB large pages (if Memory::MF_HUGE_HINT is provided)

Currently, Memory::MF_HUGE_HINT only works on Windows. The hint will be ignored on Linux, 4KB pages will always be returned.

Differential Revision: https://reviews.llvm.org/D58718

llvm-svn: 355065
2019-02-28 02:47:34 +00:00
Saleem Abdulrasool b67342e7cb Support: enable backtraces on Windows
Some platforms, e.g. Windows, support backtraces but don't have
BACKTRACE. Checking for BACKTRACE prevents Windows from having
backtraces.

Patch by Jason Mittertreiner!

llvm-svn: 354951
2019-02-27 03:21:50 +00:00
Ganesh Gopalasubramanian e172d7008d [X86] AMD znver2 enablement
This patch enables the following

1) AMD family 17h "znver2" tune flag (-march, -mcpu).
2) ISAs that are enabled for "znver2" architecture.
3) For the time being, it uses the znver1 scheduler model.
4) Tests are updated.
5) Scheduler descriptions are yet to be put in place.

Reviewers: craig.topper

Differential Revision: https://reviews.llvm.org/D58343

llvm-svn: 354897
2019-02-26 16:55:10 +00:00
Duncan P. N. Exon Smith e7b9464943 VFS: Avoid some unnecessary std::string copies
Thread Twine a little deeper through the VFS to avoid unnecessarily
constructing the same std::string twice in a parameter sequence:

    Twine -> std::string -> StringRef -> std::string

Changing a few parameters from StringRef to Twine avoids the early call
to `Twine::str()`.

llvm-svn: 354739
2019-02-23 23:48:47 +00:00
Daniel Sanders e1414d1760 Annotate timeline in Instruments with passes and other timed regions.
Summary:
Instruments is a useful tool for finding performance issues in LLVM but it can
be difficult to identify regions of interest on the timeline that we can use
to filter the profiler or allocations instrument. Xcode 10 and the latest
macOS/iOS/etc. added support for the os_signpost() API which allows us to
annotate the timeline with information that's meaningful to LLVM.

This patch causes timer start and end events to emit signposts. When used with
-time-passes, this causes the passes to be annotated on the Instruments timeline.
In addition to visually showing the duration of passes on the timeline, it also
allows us to filter the profile and allocations instrument down to an individual
pass allowing us to find the issues within that pass without being drowned out
by the noise from other parts of the compiler.

Using this in conjunction with the Time Profiler (in high frequency mode) and
the Allocations instrument is how I found the SparseBitVector that should have
been a BitVector and the DenseMap that could be replaced by a sorted vector a
couple months ago. I added NamedRegionTimers to TableGen and used the resulting
annotations to identify the slow portions of the Register Info Emitter. Some of
these were placed according to educated guesses while others were placed
according to hot functions from a previous profile. From there I filtered the
profile to a slow portion and the aforementioned issues stood out in the
profile.

To use this feature enable LLVM_SUPPORT_XCODE_SIGNPOSTS in CMake and run the
compiler under Instruments with -time-passes like so:
  instruments -t 'Time Profiler' bin/llc -time-passes -o - input.ll'
Then open the resulting trace in Instruments.

There was a talk at WWDC 2018 that explained the feature which can be found at
https://developer.apple.com/videos/play/wwdc2018/405/ if you'd like to know
more about it.

Reviewers: bogner

Reviewed By: bogner

Subscribers: jdoerfert, mgorny, kristina, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D52954

llvm-svn: 354365
2019-02-19 18:18:31 +00:00
Kristina Brooks 440f8f0c2b [LLVMSupport]: Remove a severely outdated README.
The LLVM Support library implementation has resided in
//llvm/lib/Support for a significant amount of time now,
with documentation having been updated with all references
to the "System library" being replaced with "Support library".

Since this file mirrors already existing documentation available
for Support library, includes dead links to documentation and
still refers to it as "System library", having it there is
confusing and updating it has very little point as it duplicates
information in documentation, except documentation is a lot more
up to date while this file has not been maintained.

Up to date documentation concerning this can be found here:
  http://llvm.org/docs/SupportLibrary.html

llvm-svn: 354209
2019-02-17 01:52:18 +00:00
Sam McCall 15e475e222 Reapply [VFS] Allow multiple RealFileSystem instances with independent CWDs.
This reverts commit r351091.
The original mac breakages are addressed by ensuring the root directory
we're working from is fully symlink-resolved before starting.

Differential Revision: https://reviews.llvm.org/D58169

llvm-svn: 354026
2019-02-14 12:57:01 +00:00
Andrew Ng d27cf27eb1 [Support] Fix TempFile::discard to not leave behind temporary files
Moved the remove of the temporary file to after the close to avoid
remove failures caused by ETXTBSY errors.

This issue was seen when FileOutputBuffer falls back to an in memory
buffer due to the inability to mmap the on disk file. This occurred when
running LLD on an Ubuntu VM in VirtualBox on a Windows host attempting
to write the output to a VirtualBox shared folder.

Differential Revision: https://reviews.llvm.org/D57960

llvm-svn: 354017
2019-02-14 11:08:49 +00:00
Craig Topper fa533f2152 [X86] Add 'mpx' to getHostCPUFeatures.
llvm-svn: 353974
2019-02-13 20:12:41 +00:00
Craig Topper 6829ca975d [X86] Add 'fxsr' to the getHostCPUFeatures detection code.
We implicitly mark this feature as enabled when the target is 64-bits, but our detection code for -march=native didn't support it so you can't detect it on 32-bit targets.

llvm-svn: 353963
2019-02-13 18:21:36 +00:00
Mikhail R. Gadelha 3289ccd848 This reverts commit 1440a848a635849b97f7a5cfa0ecc40d37451f5b.
and commit a1853e834c65751f92521f7481b15cf0365e796b.

They broke arm and aarch64

llvm-svn: 353590
2019-02-09 00:46:12 +00:00
Adrian Prantl e794db8817 Move SMTSolver dump() methods out-of-line.
This broke modularized non-local-submodule-visibility builds because
the function bodies pulled in extra dependencies.

llvm-svn: 353465
2019-02-07 21:03:18 +00:00
Jiong Wang 66b18e5755 [BPF] add code-gen support for JMP32 instructions
JMP32 instructions has been added to eBPF ISA. They are 32-bit variants of
existing BPF conditional jump instructions, but the comparison happens on
low 32-bit sub-register only, therefore some unnecessary extensions could
be saved.

JMP32 instructions will only be available for -mcpu=v3. Host probe hook has
been updated accordingly.

JMP32 instructions will only be enabled in code-gen when -mattr=+alu32
enabled, meaning compiling the program using sub-register mode.

For JMP32 encoding, it is a new instruction class, and is using the
reserved eBPF class number 0x6.

This patch has been tested by compiling and running kernel bpf selftests
with JMP32 enabled.

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 353384
2019-02-07 10:43:09 +00:00
Mikhail R. Gadelha eac500f0c3 Move the SMT API to LLVM
Moved everything SMT-related to LLVM and updated the cmake scripts.

Differential Revision: https://reviews.llvm.org/D54978

llvm-svn: 353373
2019-02-07 03:19:45 +00:00
Brad Smith 01227fea9e Add OpenBSD support to be able to get the thread name
llvm-svn: 353367
2019-02-07 02:06:58 +00:00
Peter Collingbourne 02fc3c696c build: Remove the cmake check for malloc.h.
As far as I can tell, malloc.h is only being used here to provide
a definition of mallinfo (malloc itself is declared in stdlib.h via
cstdlib). We already have a macro for whether mallinfo is available,
so switch to using that instead.

Differential Revision: https://reviews.llvm.org/D57807

llvm-svn: 353329
2019-02-06 19:20:47 +00:00
Thomas Preud'homme f929a0f81b Recommit: Add support for prefix-only CLI options
Summary:
Add support for options that always prefix their value, giving an error
if the value is in the next argument or if the option is given a value
assignment (ie. opt=val). This is the desired behavior for the -D option
of FileCheck for instance.

Copyright:
- Linaro (changes in version 2 of revision D55940)
- GraphCore (changes in later versions and introduced when creating
  D56549)

Reviewers: jdenny

Subscribers: llvm-commits, probinson, kristina, hiraditya,
JonChesterfield

Differential Revision: https://reviews.llvm.org/D56549

llvm-svn: 353172
2019-02-05 14:17:16 +00:00
James Henderson 9652652a32 [CommandLine] Don't print empty sentinel values from EnumValN lists in help text
In order to make an option value truly optional, both the ValueOptional
attribute and an empty-named value are required. Prior to this change,
this empty-named value appears in the command-line help text:

-some-option - some help text
  =v1        - description 1
  =v2        - description 2
  =          -

This change improves the help text for these sort of options in a number
of ways:

1) ValueOptional options with an empty-named value now print their help
   text twice: both without and then with '=<value>' after the name. The
   latter version then lists the allowed values after it.
2) Empty-named values with no help text in ValueOptional options are not
   listed in the permitted values.

-some-option         - some help text
-some-option=<value> - some help text
  =v1                - description 1
  =v2                - description 2

3) Otherwise empty-named options are printed as =<empty> rather than
   simply '='.
4) Option values without help text do not have the '-' separator
   printed.

-some-option=<value> - some help text
  =v1                - description 1
  =v2
  =<empty>           - description

It also tweaks the llvm-symbolizer -functions help text to not print a
trailing ':' as that looks bad combined with 1) above.

This is mostly a reland of r353048 which in turn was a reland of
r352750.

Reviewed by: ruiu, thopre, mstorsjo

Differential Revision: https://reviews.llvm.org/D57030

llvm-svn: 353053
2019-02-04 16:17:57 +00:00
James Henderson c9e6861a76 Revert r353048.
It was causing unexpected unit test failures on build bots.

llvm-svn: 353050
2019-02-04 15:09:58 +00:00
James Henderson d90b5a2e51 [CommandLine] Don't print empty sentinel values from EnumValN lists in help text
In order to make an option value truly optional, both the ValueOptional
attribute and an empty-named value are required. Prior to this change,
this empty-named value appears in the command-line help text:

-some-option - some help text
  =v1        - description 1
  =v2        - description 2
  =          -

This change improves the help text for these sort of options in a number
of ways:

1) ValueOptional options with an empty-named value now print their help
   text twice: both without and then with '=<value>' after the name. The
   latter version then lists the allowed values after it.
2) Empty-named values with no help text in ValueOptional options are not
   listed in the permitted values.

-some-option         - some help text
-some-option=<value> - some help text
  =v1                - description 1
  =v2                - description 2

3) Otherwise empty-named options are printed as =<empty> rather than
   simply '='.
4) Option values without help text do not have the '-' separator
   printed.

-some-option=<value> - some help text
  =v1                - description 1
  =v2
  =<empty>           - description

It also tweaks the llvm-symbolizer -functions help text to not print a
trailing ':' as that looks bad combined with 1) above.

This is mostly a reland of r352750.

Reviewed by: ruiu, thopre, mstorsjo

Differential Revision: https://reviews.llvm.org/D57030

llvm-svn: 353048
2019-02-04 14:48:33 +00:00
James Henderson 212833ce76 Revert r352750.
This was causing a build bot failure:
http://green.lab.llvm.org/green/job/clang-stage2-Rthinlto/15346/

llvm-svn: 352848
2019-02-01 10:38:40 +00:00
James Henderson 140f75f625 [CommandLine] Improve help text for cl::values style options
In order to make an option value truly optional, both the ValueOptional
and an empty-named value are required. This empty-named value appears in
the command-line help text, which is not ideal.

This change improves the help text for these sort of options in a number
of ways:
1) ValueOptional options with an empty-named value now print their help
text twice: both without and then with '=<value>' after the name. The
latter version then lists the allowed values after it.
2) Empty-named values with no help text in ValueOptional options are not
listed in the permitted values.
3) Otherwise empty-named options are printed as =<empty> rather than
simply '='.
4) Option values without help text do not have the '-' separator
printed.

It also tweaks the llvm-symbolizer -functions help text to not print a
trailing ':' as that looks bad combined with 1) above.

Reviewed by: thopre, ruiu

Differential Revision: https://reviews.llvm.org/D57030

llvm-svn: 352750
2019-01-31 13:58:48 +00:00
Thomas Preud'homme 5cb1193075 Revert "Add support for prefix-only CLI options"
This reverts commit r351038.

llvm-svn: 352310
2019-01-27 09:02:46 +00:00
Sam McCall 1e7491ea9c [JSON] Work around excess-precision issue when comparing T_Integer numbers.
Reviewers: bkramer

Subscribers: kristina, llvm-commits

Differential Revision: https://reviews.llvm.org/D57237

llvm-svn: 352204
2019-01-25 15:05:33 +00:00
Rui Ueyama 7c8fc8142e MemoryBlock: Do not automatically extend a given size to a multiple of page size.
Previously, MemoryBlock automatically extends a requested buffer size to a
multiple of page size because (I believe) doing it was thought to be harmless
and with that you could get more memory (on average 2KiB on 4KiB-page systems)
"for free".

That programming interface turned out to be error-prone. If you request N
bytes, you usually expect that a resulting object returns N for `size()`.
That's not the case for MemoryBlock.

Looks like there is only one place where we take the advantage of
allocating more memory than the requested size. So, with this patch, I
simply removed the automatic size expansion feature from MemoryBlock
and do it on the caller side when needed. MemoryBlock now always
returns a buffer whose size is equal to the requested size.

Differential Revision: https://reviews.llvm.org/D56941

llvm-svn: 351916
2019-01-23 02:03:26 +00:00
Rui Ueyama 21d451caa0 FileOutputBuffer: handle mmap(2) failure
If the underlying filesystem does not support mmap system call,
FileOutputBuffer may fail when it attempts to mmap an output temporary
file. This patch handles such situation.

Unfortunately, it looks like it is very hard to test this functionality
without a filesystem that doesn't support mmap using llvm-lit. I tested
this locally by passing an invalid parameter to mmap so that it fails and
falls back to the in-memory buffer. Maybe that's all what we can do.
I believe it is reasonable to submit this without a test.

Differential Revision: https://reviews.llvm.org/D56949

llvm-svn: 351883
2019-01-22 21:49:56 +00:00
Joel E. Denny 352695c336 [FileCheck] Suppress old -v/-vv diags if dumping input
The old diagnostic form of the trace produced by -v and -vv looks
like:

```
check1:1:8: remark: CHECK: expected string found in input
CHECK: abc
       ^
<stdin>:1:3: note: found here
; abc def
  ^~~
```

When dumping annotated input is requested (via -dump-input), I find
that this old trace is not useful and is sometimes harmful:

1. The old trace is mostly redundant because the same basic
   information also appears in the input dump's annotations.

2. The old trace buries any error diagnostic between it and the input
   dump, but I find it useful to see any error diagnostic up front.

3. FILECHECK_OPTS=-dump-input=fail requests annotated input dumps only
   for failed FileCheck calls.  However, I have to also add -v or -vv
   to get a full set of annotations, and that can produce massive
   output from all FileCheck calls in all tests.  That's a real
   problem when I run this in the IDE I use, which grinds to a halt as
   it tries to capture all that output.

When -dump-input=fail|always, this patch suppresses the old trace from
-v or -vv.  Error diagnostics still print as usual.  If you want the
old trace, perhaps to see variable expansions, you can set
-dump-input=none (the default).

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D55825

llvm-svn: 351881
2019-01-22 21:41:42 +00:00
Rui Ueyama 4063cfc745 FileOutputBuffer: Handle "-" as stdout.
I was honestly a bit surprised that we didn't do this before. This
patch is to handle "-" as the stdout so that if you pass `-o -` to
lld, for example, it writes an output to stdout instead of file `-`.

I thought that we might want to handle this at a higher level than
FileOutputBuffer, because if we land this patch, we can no longer
create a file whose name is `-` (there's a workaround though; you can
pass `./-` instead of `-`). However, because raw_fd_ostream already
handles `-` as a special file name, I think it's okay and actually
consistent to handle `-` as a special name in FileOutputBuffer.

Differential Revision: https://reviews.llvm.org/D56940

llvm-svn: 351852
2019-01-22 18:44:04 +00:00
Chandler Carruth 57b08b0944 Update more file headers across all of the LLVM projects in the monorepo
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351648
2019-01-19 10:56:40 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Rui Ueyama 8e7600dc43 Remove F_modify flag from FileOutputBuffer.
This code is dead. There is no use of the feature in the entire LLVM codebase.

Differential Revision: https://reviews.llvm.org/D56939

llvm-svn: 351613
2019-01-19 00:07:57 +00:00
Pavel Labath 47e9a21d34 [ADT] Add streaming operators for llvm::Optional
Summary:
The operators simply print the underlying value or "None".

The trickier part of this patch is making sure the streaming operators
work even in unit tests (which was my primary motivation, though I can
also see them being useful elsewhere). Since the stream operator was a
template, implicit conversions did not kick in, and our gtest glue code
was explicitly introducing an implicit conversion to make sure other
implicit conversions do not kick in :P. I resolve that by specializing
llvm_gtest::StreamSwitch for llvm:Optional<T>.

Reviewers: sammccall, dblaikie

Reviewed By: sammccall

Subscribers: mgorny, dexonsmith, kristina, llvm-commits

Differential Revision: https://reviews.llvm.org/D56795

llvm-svn: 351548
2019-01-18 12:52:03 +00:00
Erik Pilkington 5094e5ef8b NFC: Make the copies of the demangler byte-for-byte identical
With this patch, the copies of the files ItaniumDemangle.h,
StringView.h, and Utility.h are kept byte-for-byte in sync between
libcxxabi and llvm. All differences (namespaces, fallthrough, and
unreachable macros) are defined in each copies' DemanglerConfig.h.

This patch also adds a script to copy changes from libcxxabi
(cp-to-llvm.sh), and a README.txt explaining the situation.

Differential revision: https://reviews.llvm.org/D53538

llvm-svn: 351474
2019-01-17 20:37:51 +00:00
Pavel Labath 1ad53ca2b0 [Support] Remove error return value from one overload of fs::make_absolute
Summary:
The version of make_absolute which accepted a specific directory to use
as the "base" for the computation could never fail, even though it
returned a std::error_code. The reason for that seems to be historical
-- the CWD flavour (which can fail due to failure to retrieve CWD) was
there first, and the new version was implemented by extending that.

This removes the error return value from the non-CWD overload and
reimplements the CWD version on top of that. This enables us to remove
some dead code where people were pessimistically trying to handle the
errors returned from this function.

Reviewers: zturner, sammccall

Subscribers: hiraditya, kristina, llvm-commits

Differential Revision: https://reviews.llvm.org/D56599

llvm-svn: 351317
2019-01-16 09:55:32 +00:00
Dan Gohman 9299637d3c [WebAssembly] COWS has been renamed to WASI.
llvm-svn: 351297
2019-01-16 05:23:52 +00:00
Jonas Devlieghere 1a0ce65ad3 [VFS] Move RedirectingFileSystem interface into header (NFC)
This moves the RedirectingFileSystem into the header so it can be
extended. This is needed in LLDB we need a way to obtain the external
path to deal with FILE* and file descriptor APIs.

Discussion on the mailing list:
http://lists.llvm.org/pipermail/llvm-dev/2018-November/127755.html

Differential revision: https://reviews.llvm.org/D54277

llvm-svn: 351265
2019-01-15 22:36:41 +00:00
Craig Topper 99fcbf67d0 [Nios2] Remove Nios2 backend
As mentioned here http://lists.llvm.org/pipermail/llvm-dev/2019-January/129121.html This backend is incomplete and has not been maintained in several months.

Differential Revision: https://reviews.llvm.org/D56691

llvm-svn: 351231
2019-01-15 19:59:19 +00:00
Dan Gohman 1839dfd6d4 [WebAssembly] Support multilibs for wasm32 and add a wasm OS that uses it
This adds support for multilib paths for wasm32 targets, following
[Debian's Multiarch conventions], and also adds an experimental OS name in
order to test it.

[Debian's Multiarch conventions]: https://wiki.debian.org/Multiarch/

Differential Revision: https://reviews.llvm.org/D56553

llvm-svn: 351163
2019-01-15 06:58:13 +00:00
Amara Emerson e07cdb107e Revert "[VFS] Allow multiple RealFileSystem instances with independent CWDs."
This reverts commit r351079, r351069 and r351050 as it broken the greendragon bots on macOS.

llvm-svn: 351091
2019-01-14 18:32:09 +00:00
Sam McCall 7a99727c62 [VFS] Fix unused variable warning. NFC
llvm-svn: 351069
2019-01-14 14:13:24 +00:00
Sam McCall c2b310aedf [VFS] Allow multiple RealFileSystem instances with independent CWDs.
Summary:
Previously only one RealFileSystem instance was available, and its working
directory is shared with the process. This doesn't work well for multithreaded
programs that want to work with relative paths - the vfs::FileSystem is assumed
to provide the working directory, but a thread cannot control this exclusively.

The new vfs::createPhysicalFileSystem() factory copies the process's working
directory initially, and then allows it to be independently modified.

This implementation records the working directory path, and glues it to relative
paths to provide the correct absolute path to the sys::fs:: functions.
This will give different results in unusual situations (e.g. the CWD is moved).

The main alternative is the use of openat(), fstatat(), etc to ask the OS to
resolve paths relative to a directory handle which can be kept open. This is
more robust. There are two reasons not to do this initially:
1. these functions are not available on all supported Unixes, and are somewhere
   between difficult and unavailable on Windows. So we need a path-based
   fallback anyway.
2. this would mean also adding support at the llvm::sys::fs level, which is a
   larger project. My clearest idea is an OS-specific `BaseDirectory` object
   that can be optionally passed to functions there. Eventually this could be
   backed by either paths or a fd where openat() is supported.
   This is a large project, and demonstrating here that a path-based fallback
   works is a useful prerequisite.

There is some subtlety to the path-manipulation mechanism:
  - when setting the working directory, both Specified=makeAbsolute(path) and
    Resolved=realpath(path) are recorded. These may differ in the presence of
    symlinks.
  - getCurrentWorkingDirectory() and makeAbsolute() use Specified - this is
    similar to the behavior of $PWD and sys::path::current_path
  - IO operations like openFileForRead use Resolved. This is similar to the
    behavior of an openat() based implementation, that doesn't see changes
    in symlinks.
There may still be combinations of operations and FS states that yield unhelpful
behavior. This is hard to avoid with symlinks and FS abstractions :(

The caching behavior of the current working directory is removed in this patch.
getRealFileSystem() is now specified to link to the process CWD, so the caching
is incorrect.
The user who needed this so far is clangd, which will immediately switch to
createPhysicalFileSystem().

Reviewers: ilya-biryukov, bkramer, labath

Subscribers: ioeric, kadircet, kristina, llvm-commits

Differential Revision: https://reviews.llvm.org/D56545

llvm-svn: 351050
2019-01-14 10:56:35 +00:00
Thomas Preud'homme bc5e6ee87a Add support for prefix-only CLI options
Summary:
Add support for options that always prefix their value, giving an error
if the value is in the next argument or if the option is given a value
assignment (ie. opt=val). This is the desired behavior for the -D option
of FileCheck for instance.

Copyright:
- Linaro (changes in version 2 of revision D55940)
- GraphCore (changes in later versions and introduced when creating
  D56549)

Reviewers: jdenny

Subscribers: llvm-commits, probinson, kristina, hiraditya,
JonChesterfield

Differential Revision: https://reviews.llvm.org/D56549

llvm-svn: 351038
2019-01-14 09:28:53 +00:00
Zachary Turner 4e83923d83 Don't write #include "Windows/WindowsSupport.h" from the Windows dir.
This generates -Wnonportable-include-dir warnings, and doesn't need
to be there.  It seems this was just checked in on accident.

llvm-svn: 350655
2019-01-08 21:05:34 +00:00
David Bolvansky 90004149cc [NFC] Fixed extra semicolon warning
-This line, and those below, will be ignored--

M    lib/Support/Error.cpp

llvm-svn: 350162
2018-12-30 13:18:17 +00:00
Richard Trieu a87b70d1db Add vtable anchor to classes.
llvm-svn: 350142
2018-12-29 02:02:13 +00:00
Alexandre Ganea b536bf5299 Buildfix for r345516 (Clang compilation failing).
llvm-svn: 349518
2018-12-18 18:23:36 +00:00