Summary:
This consists of four main parts:
- an type json::Expr representing JSON values of dynamic kind, which can be
composed, inspected, and modified
- a JSON parser from string -> json::Expr
- a JSON printer from json::Expr -> string, with optional pretty-printing
- a convention for mapping json::Expr <=> native types (fromJSON/toJSON)
Mapping functions are provided for primitives (e.g. int, vector) and the
ObjectMapper helper helps implement fromJSON for struct/object types.
Based on clangd's usage, a couple of places I'd appreciate review attention:
- fromJSON returns only bool. A richer error-signaling mechanism may be useful
to provide useful messages, or let recursive fromJSONs (containers/structs)
do careful error recovery.
- should json::obj be always explicitly written (like json::ary)
- there's no streaming parse API. I suspect there are some simple wins like
a callback API where the document is a long array, and each element is small.
But this can probably be bolted on easily when we see the need.
Reviewers: bkramer, labath
Subscribers: mgorny, ilya-biryukov, ioeric, MaskRay, llvm-commits
Differential Revision: https://reviews.llvm.org/D45753
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336534 91177308-0d34-0410-b5e6-96231b3b80d8
introducing llvm::trivially_{copy,move}_constructible type traits.
This uses a completely portable implementation of these traits provided
by Richard Smith. You can see it on compiler explorer in all its glory:
https://godbolt.org/g/QEDZjW
I have transcribed it, clang-formatted it, added some comments, and made
the tests fit into a unittest file.
I have also switched llvm::unique_function over to use these new, much
more portable traits. =D
Hopefully this will fix the build bot breakage from my prior commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336161 91177308-0d34-0410-b5e6-96231b3b80d8
We have ThreadPool, which can execute work asynchronously on N
background threads, but sometimes you need to make sure the work
is executed asynchronously but also serially. That is, if task
B is enqueued after task A, then task B should not begin until
task A has completed. This patch adds such a class.
Differential Revision: https://reviews.llvm.org/D48240
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335440 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This kind of functionality is useful to other project apart from clang.
LLDB works with version numbers a lot, but it does not have a convenient
abstraction for this. Moving this class to a lower level library allows
it to be freely used within LLDB.
Since this class is used in a lot of places in clang, and it used to be
in the clang namespace, it seemed appropriate to add it to the list of
adopted classes in LLVM.h to avoid prefixing all uses with "llvm::".
Also, I didn't find any tests specific for this class, so I wrote a
couple of quick ones for the more interesting bits of functionality.
Reviewers: zturner, erik.pilkington
Subscribers: mgorny, cfe-commits, llvm-commits
Differential Revision: https://reviews.llvm.org/D47887
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334399 91177308-0d34-0410-b5e6-96231b3b80d8
The issue was that the has function was generating different results depending
on the signedness of char on the host platform. This commit fixes the issue by
explicitly using an unsigned char type to prevent sign extension and
adds some extra tests.
The original commit message was:
This patch implements a variant of the DJB hash function which folds the
input according to the algorithm in the Dwarf 5 specification (Section
6.1.1.4.5), which in turn references the Unicode Standard (Section 5.18,
"Case Mappings").
To achieve this, I have added a llvm::sys::unicode::foldCharSimple
function, which performs this mapping. The implementation of this
function was generated from the CaseMatching.txt file from the Unicode
spec using a python script (which is also included in this patch). The
script tries to optimize the function by coalescing adjecant mappings
with the same shift and stride (terms I made up). Theoretically, it
could be made a bit smarter and merge adjecant blocks that were
interrupted by only one or two characters with exceptional mapping, but
this would save only a couple of branches, while it would greatly
complicate the implementation, so I deemed it was not worth it.
Since we assume that the vast majority of the input characters will be
US-ASCII, the folding hash function has a fast-path for handling these,
and only whips out the full decode+fold+encode logic if we encounter a
character outside of this range. It might be possible to implement the
folding directly on utf8 sequences, but this would also bring a lot of
complexity for the few cases where we will actually need to process
non-ascii characters.
Reviewers: JDevlieghere, aprantl, probinson, dblaikie
Subscribers: mgorny, hintonda, echristo, clayborg, vleschuk, llvm-commits
Differential Revision: https://reviews.llvm.org/D42740
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325732 91177308-0d34-0410-b5e6-96231b3b80d8
The "knownValuesUnicode" test in the patch fails on ppc64 and arm64
bots. Reverting while I investigate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325115 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch implements a variant of the DJB hash function which folds the
input according to the algorithm in the Dwarf 5 specification (Section
6.1.1.4.5), which in turn references the Unicode Standard (Section 5.18,
"Case Mappings").
To achieve this, I have added a llvm::sys::unicode::foldCharSimple
function, which performs this mapping. The implementation of this
function was generated from the CaseMatching.txt file from the Unicode
spec using a python script (which is also included in this patch). The
script tries to optimize the function by coalescing adjecant mappings
with the same shift and stride (terms I made up). Theoretically, it
could be made a bit smarter and merge adjecant blocks that were
interrupted by only one or two characters with exceptional mapping, but
this would save only a couple of branches, while it would greatly
complicate the implementation, so I deemed it was not worth it.
Since we assume that the vast majority of the input characters will be
US-ASCII, the folding hash function has a fast-path for handling these,
and only whips out the full decode+fold+encode logic if we encounter a
character outside of this range. It might be possible to implement the
folding directly on utf8 sequences, but this would also bring a lot of
complexity for the few cases where we will actually need to process
non-ascii characters.
Reviewers: JDevlieghere, aprantl, probinson, dblaikie
Subscribers: mgorny, hintonda, echristo, clayborg, vleschuk, llvm-commits
Differential Revision: https://reviews.llvm.org/D42740
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325107 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This did not work because the ExpectedHolder was trying to hold the
value in an Optional<T*>. Instead of trying to mimic the behavior of
Expected and try to make ExpectedHolder work with references and
non-references, I simply store the reference to the Expected object in
the holder.
I also add a bunch of tests for these matchers, which have helped me
flesh out some problems in my initial implementation of this patch, and
uncovered the fact that we are not consistent in quoting our values in
the matcher output (which I also fix).
Reviewers: zturner, chandlerc
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D40904
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320025 91177308-0d34-0410-b5e6-96231b3b80d8
We currently use target_link_libraries without an explicit scope
specifier (INTERFACE, PRIVATE or PUBLIC) when linking executables.
Dependencies added in this way apply to both the target and its
dependencies, i.e. they become part of the executable's link interface
and are transitive.
Transitive dependencies generally don't make sense for executables,
since you wouldn't normally be linking against an executable. This also
causes issues for generating install export files when using
LLVM_DISTRIBUTION_COMPONENTS. For example, clang has a lot of LLVM
library dependencies, which are currently added as interface
dependencies. If clang is in the distribution components but the LLVM
libraries it depends on aren't (which is a perfectly legitimate use case
if the LLVM libraries are being built static and there are therefore no
run-time dependencies on them), CMake will complain about the LLVM
libraries not being in export set when attempting to generate the
install export file for clang. This is reasonable behavior on CMake's
part, and the right thing is for LLVM's build system to explicitly use
PRIVATE dependencies for executables.
Unfortunately, CMake doesn't allow you to mix and match the keyword and
non-keyword target_link_libraries signatures for a single target; i.e.,
if a single call to target_link_libraries for a particular target uses
one of the INTERFACE, PRIVATE, or PUBLIC keywords, all other calls must
also be updated to use those keywords. This means we must do this change
in a single shot. I also fully expect to have missed some instances; I
tested by enabling all the projects in the monorepo (except dragonegg),
and configuring both with and without shared libraries, on both Darwin
and Linux, but I'm planning to rely on the buildbots for other
configurations (since it should be pretty easy to fix those).
Even after this change, we still have a lot of target_link_libraries
calls that don't specify a scope keyword, mostly for shared libraries.
I'm thinking about addressing those in a follow-up, but that's a
separate change IMO.
Differential Revision: https://reviews.llvm.org/D40823
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319840 91177308-0d34-0410-b5e6-96231b3b80d8
The difference from the previous version is the use of decltype, as the
implementation of std::result_of in libc++ did not work correctly for
variadic function like open(2).
Original summary:
This function retries an operation if it was interrupted by a signal
(failed with EINTR). It's inspired by the TEMP_FAILURE_RETRY macro in
glibc, but I've turned that into a template function. I've also added a
fail-value argument, to enable the function to be used with e.g.
fopen(3), which is documented to fail for any reason that open(2) can
fail (which includes EINTR).
The main user of this function will be lldb, but there were also a
couple of uses within llvm that I could simplify using this function.
Reviewers: zturner, silvas, joerg
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D33895
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306671 91177308-0d34-0410-b5e6-96231b3b80d8
The fix in r306003 uncovered a pretty fundamental problem that libc++
implementation of std::result_of does not handle the prototype of
open(2) correctly (presumably because it contains ...). This makes the
whole function unusable in its current form, so I am also reverting the
original commit (r305892), which introduced the function, at least until
I figure out a way to solve the libc++ issue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306005 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This function retries an operation if it was interrupted by a signal
(failed with EINTR). It's inspired by the TEMP_FAILURE_RETRY macro in
glibc, but I've turned that into a template function. I've also added a
fail-value argument, to enable the function to be used with e.g.
fopen(3), which is documented to fail for any reason that open(2) can
fail (which includes EINTR).
The main user of this function will be lldb, but there were also a
couple of uses within llvm that I could simplify using this function.
Reviewers: zturner, silvas, joerg
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D33895
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305892 91177308-0d34-0410-b5e6-96231b3b80d8
Instead use target_link_libraries directly. Thanks to
Juergen Ributzka for the suggestion, which fixes an issue
when llvm is configured with no targets.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305421 91177308-0d34-0410-b5e6-96231b3b80d8
Many times unit tests for different libraries would like to use
the same helper functions for checking common types of errors.
This patch adds a common library with helpers for testing things
in Support, and introduces helpers in here for integrating the
llvm::Error and llvm::Expected<T> classes with gtest and gmock.
Normally, we would just be able to write:
EXPECT_THAT(someFunction(), succeeded());
but due to some quirks in llvm::Error's move semantics, gmock
doesn't make this easy, so two macros EXPECT_THAT_ERROR() and
EXPECT_THAT_EXPECTED() are introduced to gloss over the difficulties.
Consider this an exception, and possibly only temporary as we
look for ways to improve this.
Differential Revision: https://reviews.llvm.org/D33059
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305395 91177308-0d34-0410-b5e6-96231b3b80d8
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304864 91177308-0d34-0410-b5e6-96231b3b80d8
We have to check gCrashRecoveryEnabled before using __try.
In other words, SEH works too well and we ended up recovering from
crashes in implicit module builds that we weren't supposed to. Only
libclang is supposed to enable CrashRecoveryContext to allow implicit
module builds to crash.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303279 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
It avoids problems when other libraries raise exceptions. In particular,
OutputDebugString raises an exception that the debugger is supposed to
catch and suppress. VEH kicks in first right now, and that is entirely
incorrect.
Unfortunately, GCC does not support SEH, so I've kept the old buggy VEH
codepath around. We could fix it with SetUnhandledExceptionFilter, but
that is not per-thread, so a well-behaved library shouldn't set it.
Reviewers: zturner
Subscribers: llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D33261
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303274 91177308-0d34-0410-b5e6-96231b3b80d8
libraries are properly unloaded when llvm_shutdown is called.
Summary:
This was mostly affecting usage of the JIT, where storing the library handles in
a set made iteration unordered/undefined. This lead to disagreement between the
JIT and native code as to what the address and implementation of particularly on
Windows with stdlib functions:
JIT: putenv_s("TEST", "VALUE") // called msvcrt.dll, putenv_s
JIT: getenv("TEST") -> "VALUE" // called msvcrt.dll, getenv
Native: getenv("TEST") -> NULL // called ucrt.dll, getenv
Also fixed is the issue of DynamicLibrary::getPermanentLibrary(0,0) on Windows
not giving priority to the process' symbols as it did on Unix.
Reviewers: chapuni, v.g.vassilev, lhames
Reviewed By: lhames
Subscribers: danalbert, srhines, mgorny, vsk, llvm-commits
Differential Revision: https://reviews.llvm.org/D30107
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301562 91177308-0d34-0410-b5e6-96231b3b80d8
libraries are properly unloaded when llvm_shutdown is called.
Summary:
This was mostly affecting usage of the JIT, where storing the library handles in
a set made iteration unordered/undefined. This lead to disagreement between the
JIT and native code as to what the address and implementation of particularly on
Windows with stdlib functions:
JIT: putenv_s("TEST", "VALUE") // called msvcrt.dll, putenv_s
JIT: getenv("TEST") -> "VALUE" // called msvcrt.dll, getenv
Native: getenv("TEST") -> NULL // called ucrt.dll, getenv
Also fixed is the issue of DynamicLibrary::getPermanentLibrary(0,0) on Windows
not giving priority to the process' symbols as it did on Unix.
Reviewers: chapuni, v.g.vassilev, lhames
Reviewed By: lhames
Subscribers: danalbert, srhines, mgorny, vsk, llvm-commits
Differential Revision: https://reviews.llvm.org/D30107
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301236 91177308-0d34-0410-b5e6-96231b3b80d8
The changes are causing the i686-mingw32 build to fail.
This reverts commit r301153, and the changes for a separate warning on i686-mingw32 in r301155 and r301156.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301157 91177308-0d34-0410-b5e6-96231b3b80d8
libraries are properly unloaded when llvm_shutdown is called.
Summary:
This was mostly affecting usage of the JIT, where storing the library handles in
a set made iteration unordered/undefined. This lead to disagreement between the
JIT and native code as to what the address and implementation of particularly on
Windows with stdlib functions:
JIT: putenv_s("TEST", "VALUE") // called msvcrt.dll, putenv_s
JIT: getenv("TEST") -> "VALUE" // called msvcrt.dll, getenv
Native: getenv("TEST") -> NULL // called ucrt.dll, getenv
Also fixed is the issue of DynamicLibrary::getPermanentLibrary(0,0) on Windows
not giving priority to the process' symbols as it did on Unix.
Reviewers: chapuni, v.g.vassilev, lhames
Reviewed By: lhames
Subscribers: danalbert, srhines, mgorny, vsk, llvm-commits
Differential Revision: https://reviews.llvm.org/D30107
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301153 91177308-0d34-0410-b5e6-96231b3b80d8
LLVM defines `PTHREAD_LIB` which is used by AddLLVM.cmake and various projects
to correctly link the threading library when needed. Unfortunately
`PTHREAD_LIB` is defined by LLVM's `config-ix.cmake` file which isn't installed
and therefore can't be used when configuring out-of-tree builds. This causes
such builds to fail since `pthread` isn't being correctly linked.
This patch attempts to fix that problem by renaming and exporting
`LLVM_PTHREAD_LIB` as part of`LLVMConfig.cmake`. I renamed `PTHREAD_LIB`
because It seemed likely to cause collisions with downstream users of
`LLVMConfig.cmake`.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294690 91177308-0d34-0410-b5e6-96231b3b80d8
Enable an ELFObjectFile to read the its arm build attributes to
produce a target triple with a specific ARM architecture.
llvm-objdump now uses this functionality to automatically produce
a more accurate target.
Differential Revision: https://reviews.llvm.org/D28769
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292366 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Revert [ARM] Fix ubig32_t read in ARMAttributeParser
Now using support functions to read data instead of trying to
perform casts.
===========================================================
Revert [ARM] Enable objdump to construct triple for ARM
Now that The ARMAttributeParser has been moved into the library,
it has been modified so that it can parse the attributes without
printing them and stores them in a map. ELFObjectFile now queries
the attributes to fill out the architecture details of a provided
triple for 'arm' and 'thumb' targets. llvm-objdump uses this new
functionality.
Subscribers: llvm-commits, samparker, aemerson, mgorny
Differential Revision: https://reviews.llvm.org/D28683
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291911 91177308-0d34-0410-b5e6-96231b3b80d8
Now that The ARMAttributeParser has been moved into the library,
it has been modified so that it can parse the attributes without
printing them and stores them in a map. ELFObjectFile now queries
the attributes to fill out the architecture details of a provided
triple for 'arm' and 'thumb' targets. llvm-objdump uses this new
functionality.
Differential Revision: https://reviews.llvm.org/D28281
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291898 91177308-0d34-0410-b5e6-96231b3b80d8
If we split a filename into `Name` and `Prefix`, `Prefix` is at most
145 bytes. We had a bug that didn't split a path correctly. This bug
was pointed out by Rafael in the post commit review.
This patch adds a unit test for TarWriter to verify the fix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291494 91177308-0d34-0410-b5e6-96231b3b80d8
GlobPattern is a class to handle glob pattern matching. Currently
only LLD is using that, but technically that feature is not specific
to linkers, so in this patch I move that file to LLVM.
Differential Revision: https://reviews.llvm.org/D27969
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290212 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
it's often the case when the rules in the SpecialCaseList
are of the form hel.o*bar. That gives us a chance to build
trigram index to quickly discard 99% of inputs without
running a full regex. A similar idea was used in Google Code Search
as described in the blog post:
https://swtch.com/~rsc/regexp/regexp4.html
The check is defeated, if there's at least one regex
more complicated than that. In this case, all inputs
will go through the regex. That said, the real-world
rules are often simple or can be simplied. That considerably
speeds up compiling Chromium with CFI and UBSan.
As measured on Chromium's content_message_generator.cc:
before, CFI: 44 s
after, CFI: 23 s
after, CFI, no blacklist: 23 s (~1% slower, but 3 runs were unable to show the difference)
after, regular compilation to bitcode: 23 s
Reviewers: pcc
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D27188
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288303 91177308-0d34-0410-b5e6-96231b3b80d8
This introduces a new type-safe general purpose formatting
library. It provides compile-time type safety, does not require
a format specifier (since the type is deduced), and provides
mechanisms for extending the format capability to user defined
types, and overriding the formatting behavior for existing types.
This patch additionally adds documentation for the API to the
LLVM programmer's manual.
Mailing List Thread:
http://lists.llvm.org/pipermail/llvm-dev/2016-October/105836.html
Differential Revision: https://reviews.llvm.org/D25587
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@286682 91177308-0d34-0410-b5e6-96231b3b80d8
This resubmits r284436 and r284437, which were reverted in
r284462 as they were breaking the AArch64 buildbot.
The breakage on AArch64 turned out to be a miscompile which is
still not fixed, but is actively tracked at llvm.org/pr30748.
This resubmission re-writes the code in a way so as to make the
miscompile not happen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285483 91177308-0d34-0410-b5e6-96231b3b80d8
This is a resubmission of r284590. The mingw build should be fixed now. The
problem was we were matching time_t with _localtime_64s, which was incorrect on
_USE_32BIT_TIME_T systems. Instead I use localtime_s, which should always
evaluate to the correct function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284720 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r284590 as it fails on the mingw buildbot. I think I know the
fix, but I cannot test it right now. Will reapply when I verify it works ok.
This reverts r284590.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284615 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
std::chrono mostly covers the functionality of llvm::sys::TimeValue and
lldb_private::TimeValue. This header adds a bit of utility functions and
typedefs, which make the usage of the library and porting code from TimeValues
easier.
Rationale:
- TimePoint typedef - precision of system_clock is implementation defined -
using a well-defined precision helps maintain consistency between platforms,
makes it interact better with existing TimeValue classes, and avoids cases
there a time point is implicitly convertible to a specific precision on some
platforms but not on others.
- system_clock::to_time_t only accepts time_points with the default system
precision (even though time_t has only second precision on all platforms we
support). To avoid the need for explicit casts, I have added a toTimeT()
wrapper function. toTimePoint(time_t) was not strictly necessary, but I have
added it for symmetry.
Reviewers: zturner, mehdi_amini
Subscribers: beanz, mgorny, llvm-commits, modocache
Differential Revision: https://reviews.llvm.org/D25416
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284590 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commits 284436 and 284437 because they still break AArch64 bots:
Value of: format_number(-10, IntegerStyle::Integer, 1)
Actual: "-0"
Expected: "-10"
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284462 91177308-0d34-0410-b5e6-96231b3b80d8
This resubmits commits 284425 and r284428, which were reverted
in r284429 due to some infinite recursion caused by an incorrect
selection of function overloads. Reproduced the failure on Linux
using GCC 4.8.4, and confirmed that with the new patch the tests
path on GCC as well as MSVC. So hopefully this fixes everything.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284436 91177308-0d34-0410-b5e6-96231b3b80d8
raw_ostream has not afforded a lot of flexibility in terms of
how to format numbers when outputting. Wrap this all up into
a set of low level helper functions that can be used to output
numbers with arbitrary precision, alignment, format, etc and
then update raw_ostream to use these functions.
This will be useful for upcoming improvements to llvm's string
formatting libraries, but are still useful independently.
Differential Revision: https://reviews.llvm.org/D25497
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284425 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This will be used by ThinLTO to set the amount of backend
parallelism, which performs better when restricted to the number
of physical cores (on X86 at least, where getHostNumPhysicalCores is
currently defined). If not available this falls back to
thread::hardware_concurrency.
Note I didn't add to the thread class since that is a typedef to
std::thread where available.
Reviewers: mehdi_amini
Subscribers: beanz, llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D25585
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284180 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
For now I have only added support for x86_64 Linux, but other systems
can be added incrementally.
This is to be used for setting the default parallelism for ThinLTO
backends (instead of thread::hardware_concurrency which includes
hyperthreading and is too aggressive). I'll send this as a follow-on
patch, and it will fall back to hardware_concurrency when the new
getHostNumPhysicalCores returns -1 (when not supported for a given
host system).
I also added an interface to MemoryBuffer to force reading a file
as a stream - this is required for /proc/cpuinfo which is a special
file that looks like a normal file but appears to have 0 size.
The existing readers of this file in Host.cpp are reading the first
1024 or so bytes from it, because the necessary info is near the top.
But for the new functionality we need to be able to read the entire
file. I can go back and change the other readers to use the new
getFileAsStream as a follow-on patch since it seems much more robust.
Added a unittest.
Reviewers: mehdi_amini
Subscribers: beanz, mgorny, llvm-commits, modocache
Differential Revision: https://reviews.llvm.org/D25564
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284138 91177308-0d34-0410-b5e6-96231b3b80d8
