Commit Graph

4352 Commits

Author SHA1 Message Date
Jonas Devlieghere 425b248128 [ADT] Recognize ppc as valid architecture in target triple.
Until this patch, only `powerpc` and `ppc32` were recognized as valid
PowerPC 32-bit architectures in a target triple. This was incompatible
with the triple `ppc-apple-darwin` as returned for libObject. I found
out about this when working on a test case using a binary generated on
an old PowerBook G4.

We had the choice of either fix this in the Mach-O object parser or
in the Triple implementation. I chose the latter because it feels like
the most canonical place.

Differential revision: https://reviews.llvm.org/D43760

llvm-svn: 326182
2018-02-27 10:09:58 +00:00
Jonas Devlieghere 560ce2c70f Re-land: "[Support] Replace HashString with djbHash."
This patch removes the HashString function from StringExtraces and
replaces its uses with calls to djbHash from DJB.h.

This change is *almost* NFC. While the algorithm is identical, the
djbHash implementation in StringExtras used 0 as its default seed while
the implementation in DJB uses 5381. The latter has been shown to result
in less collisions and improved avalanching and is used by the DWARF
accelerator tables.

Because some test were implicitly relying on the hash order, I've
reverted to using zero as a seed for the following two files:

  lld/include/lld/Core/SymbolTable.h
  llvm/lib/Support/StringMap.cpp

Differential revision: https://reviews.llvm.org/D43615

llvm-svn: 326091
2018-02-26 15:16:42 +00:00
David Zarzycki f3fa88b288 Test commit
llvm-svn: 326085
2018-02-26 13:05:18 +00:00
Jonas Devlieghere 370bf3ef49 Revert "[Support] Replace HashString with djbHash."
It looks like some of our tests depend on the ordering of hashed values.
I'm reverting my changes while I try to reproduce and fix this locally.

Failing builds:

  lab.llvm.org:8011/builders/lld-x86_64-darwin13/builds/18388
  lab.llvm.org:8011/builders/clang-cmake-x86_64-sde-avx512-linux/builds/6743
  lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/15607

llvm-svn: 326082
2018-02-26 12:05:18 +00:00
Jonas Devlieghere b9ad175935 [Support] Replace HashString with djbHash.
This removes the HashString function from StringExtraces and replaces
its uses with calls to djbHash from DJB.h

This is *almost* NFC. While the algorithm is identical, the djbHash
implementation in StringExtras used 0 as its seed while the
implementation in DJB uses 5381. The latter has been shown to result in
less collisions and improved avalanching.

https://reviews.llvm.org/D43615
(cherry picked from commit 77f7f965bc9499a9ae768a296ca5a1f7347d1d2c)

llvm-svn: 326081
2018-02-26 11:30:13 +00:00
Hans Wennborg 35d6e944e1 llvm-config: Add advapi32 to --system-libs on Windows (PR36372)
llvm-svn: 325894
2018-02-23 12:20:26 +00:00
Pavel Labath 3b17b84b9c Resubmit r325107 (case folding DJB hash)
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

llvm-svn: 325732
2018-02-21 22:36:31 +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
Benjamin Kramer 92387a8744 [Support] Replace hand-written scope_exit with make_scope_exit.
No functionality change intended.

llvm-svn: 325460
2018-02-18 16:05:40 +00:00
Craig Topper 8d02be3bf3 [X86] Add 'sahf' to getHostCPUFeatures so -march=native will pick it up correctly.
Summary: We probably mostly get this right due to family/model/stepping mapping to CPU names. But we should detect it explicitly.

Reviewers: RKSimon, echristo, dim, spatel

Reviewed By: dim

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43418

llvm-svn: 325439
2018-02-17 16:52:49 +00:00
Serge Pavlov d48042efa8 Report fatal error in the case of out of memory
This is partial recommit of r325224, reverted in 325227. The relevant
part of original comment is below.

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".

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

llvm-svn: 325426
2018-02-17 10:21:33 +00:00
Tim Shen 89337750a0 [APInt] Fix extractBits to correctly handle Result.isSingleWord() case.
Summary: extractBits assumes that `!this->isSingleWord() implies !Result.isSingleWord()`, which may not necessarily be true. Handle both cases.

Reviewers: RKSimon

Subscribers: sanjoy, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D43363

llvm-svn: 325311
2018-02-16 01:44:36 +00:00
Zachary Turner 2061ad2f83 Silence warning about unused private variable.
llvm-svn: 325275
2018-02-15 18:46:59 +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 ce719a0def Specify namespace for realloc
llvm-svn: 325226
2018-02-15 09:35:36 +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
Pavel Labath 918f60056a Revert r325107 (case folding DJB hash) and subsequent build fix
The "knownValuesUnicode" test in the patch fails on ppc64 and arm64
bots. Reverting while I investigate.

llvm-svn: 325115
2018-02-14 11:06:39 +00:00
Pavel Labath f1440978a1 Implement a case-folding version of DJB hash
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

llvm-svn: 325107
2018-02-14 10:05:09 +00:00
Sam McCall 6358064d02 Fix off-by-one in set_thread_name which causes truncation to fail on Linux
llvm-svn: 325069
2018-02-13 23:23:59 +00:00
George Karpenkov 560b244c9b Make LLVM timer reprintable: that is, make more than one print action on the same timer feasible
Currently, each LLVM timer can be only printed once, as the act of
printing clears the timer.

Moreover, the current printing mechanism implicitly assumes that the
timer is stopped -- and prints zero otherwise.
This patch relaxes this assumption and makes printing statistics
multiple time a possibility.

Differential Revision: https://reviews.llvm.org/D43136

llvm-svn: 324788
2018-02-10 00:38:21 +00:00
Erich Keane 0299cc9db5 [ARM] Add 'fillValidCPUArchList' to ARM targets
This is a support change for a CFE change (https://reviews.llvm.org/D42978)
that allows march and -target-cpu to list the valid targets in a note. The changes
are limited to the ARM/AArch64, since this is the only target that gets the CPU
list from LLVM.

llvm-svn: 324623
2018-02-08 16:48:54 +00:00
Benjamin Kramer 351e9f3a73 [ADT] Replace sys::MemoryFence with standard atomics.
This is a bit faster in theory, in practice it's cold code that's only
active in !NDEBUG, so it probably doesn't make a difference. This is one
of the last users of our homegrown Atomic.h.

llvm-svn: 323999
2018-02-01 20:28:33 +00:00
Daniel Sanders 8c345dcb9b Add more initializers to quiet a clang warning
Summary:
`struct crashreporter_annotations_t` gained one more `uint64_t` field in
`CRASHREPORTER_ANNOTATIONS_VERSION` 5

causing an annoying clang warning:

```
llvm/lib/Support/PrettyStackTrace.cpp:92:65: warning: missing field 'abort_cause' initializer [-Wmissing-field-initializers]
        = { CRASHREPORTER_ANNOTATIONS_VERSION, 0, 0, 0, 0, 0, 0 };
                                                                ^
1 warning generated
```

Let's fix it.

Patch by Roman Tereshin

Reviewers: qcolombet, echristo, beanz, dexonsmith

Reviewed By: echristo

Subscribers: dsanders, dexonsmith, beanz, echristo, qcolombet, llvm-commits

Differential Revision: https://reviews.llvm.org/D42268

llvm-svn: 323777
2018-01-30 16:02:32 +00:00
Jonas Devlieghere 92ac9d3e1b [Support] Move DJB hash to support. NFC
This patch moves the DJB hash to support. This is consistent with other
hashing algorithms living there. The hash is used by the DWARF
accelerator tables. We're doing this now because the hashing function is
needed by dsymutil and we don't want to link against libBinaryFormat.

Differential revision: https://reviews.llvm.org/D42594

llvm-svn: 323616
2018-01-28 11:05:10 +00:00
Benjamin Kramer d15b2898d3 [Support] Move PrintEscapedString into the library its declaration is in
llvm-svn: 323558
2018-01-26 20:21:02 +00:00
Dan Gohman f2c1cae5cb [WebAssembly] Switch to *-wasm as the default target triple.
This makes wasm32-unknown-unknown-wasm the default, which supports
the .o file writer and the new linking ABI. To enable s2wasm-compatible
output, use the wasm32-unknown-unknown-elf triple.

llvm-svn: 323220
2018-01-23 16:55:44 +00:00
Rui Ueyama 322fcfee34 Revert r322595: Specify inline for isWhitespace in CommandLine.cpp
The original change was made based on a misunderstanding that
-DCMAKE_BUILD_TYPE=RelWithDebugInfo would produce the same executable
as -DCMAKE_BUILD_TYPE=Release modulo debug info. Turned out that's not
true -- it at least disables some optimizations such as function inlining.

llvm-svn: 323161
2018-01-22 23:27:50 +00:00
Petr Hosek cc7a8f14bd Fallback option for colorized output when terminfo isn't available
Try to detect the terminal color support by checking the value of the
TERM environment variable. This is not great, but it's better than
nothing when terminfo library isn't available, which may still be the
case on some Linux distributions.

Differential Revision: https://reviews.llvm.org/D42055

llvm-svn: 322962
2018-01-19 17:10:55 +00:00
Craig Topper 84b26b90d1 [X86] Add intrinsic support for the RDPID instruction
This adds a new instrinsic to support the rdpid instruction. The implementation is a bit weird because the intrinsic is defined as always returning 32-bits, but the assembler support thinks the instruction produces a 64-bit register in 64-bit mode. But really it zeros the upper 32 bits. So I had to add separate patterns where 64-bit mode uses an extract_subreg.

Differential Revision: https://reviews.llvm.org/D42205

llvm-svn: 322910
2018-01-18 23:52:31 +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
Peter Collingbourne 719c1f7405 Support: Add missing #include.
This #include is necessary to provide the definitions of _fpclass
and _FPCLASS_NZ when building with libc++.

llvm-svn: 322885
2018-01-18 20:49:33 +00:00
George Burgess IV 41e646d8ea [Support] Return an enum instead of an unsigned; NFC.
We seem to be (logically) returning ArchExtKinds here in all cases, so
the return type should reflect that.

The static_cast is necessary because `A.ID` is actually an `unsigned`,
presumably since we use `decltype(A)` to represent extended attributes
for both ARM and AArch64, which use distinct `ArchExtKinds`.

We can't trivially make the same change for ARM, because one of the
values it returns is the bitwise-or of two `ARM::ArchExtKind`s.

llvm-svn: 322613
2018-01-17 03:12:06 +00:00
Rui Ueyama af4ddd5a6e Specify inline for isWhitespace in CommandLine.cpp
Patch by Takuto Ikuta.

In chromium's component build, there are many directive sections and
commandline parsing takes much time.
This patch is for speed up of lld in RelWithDebInfo build by forcing
inline heavily called isWhitespace function.

10 times link perf stats of blink_core.dll changed like below.

master:
TotalSeconds: 9.8764878
TotalSeconds: 10.1455242
TotalSeconds: 10.075279
TotalSeconds: 10.3397347
TotalSeconds: 9.8361665
TotalSeconds: 9.9544441
TotalSeconds: 9.8960686
TotalSeconds: 9.8877865
TotalSeconds: 10.0551879
TotalSeconds: 10.0492254
Avg: 10.01159047

with this patch:
TotalSeconds: 8.8696762
TotalSeconds: 9.1021585
TotalSeconds: 9.0233893
TotalSeconds: 9.1886175
TotalSeconds: 9.156954
TotalSeconds: 9.0978564
TotalSeconds: 9.1316824
TotalSeconds: 8.8354606
TotalSeconds: 9.2549431
TotalSeconds: 9.4473085
Avg: 9.11080465

llvm-svn: 322595
2018-01-16 20:52:32 +00:00
Pavel Labath e04f8ab3fb [Support] Remove MemoryBuffer::getNewMemBuffer
all callers have been switched the the Writable version (which does not
require const_casting to be useful).

llvm-svn: 322475
2018-01-15 11:03:30 +00:00
Florian Hahn 4ed75a73e6 [TargetParser] Add missing armv8l ARMv8 variant.
This change adds the missing armv8l variant as an alias of armv8 architecture.
The issue was observed with several regressions in validation on armv8l
hardware (for instance ExecutionEngine/frem.ll failed due to lack of neon fpu).

Tested with regression testsuite passed without regression on ARM and x86_64.

Patch by Yvan Roux.

Reviewers: rengolin, rogfer01, olista01, fhahn

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D41859

llvm-svn: 322098
2018-01-09 17:49:25 +00:00
Davide Italiano 4762c069de [Support] Use realpath(3) instead of trying to open a file.
If we don't have read permissions on the directory the call would
fail.

<rdar://problem/35871293>

llvm-svn: 322095
2018-01-09 17:27:45 +00:00
Pavel Labath 9aaf5d3e71 [Support] Add WritableMemoryBuffer::getNewMemBuffer
Summary:
The idea is that it would replace
(non-Writable)MemoryBuffer::getNewMemBuffer, which is quite useless
unless you const_cast its contents to write to it (which all (both)
callers of this function were doing). This patch also fixes one of the usages in
COFFWriter. After fixing the other usage in clang, I plan to delete the old
function.

Reviewers: dblaikie, Bigcheese

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41540

llvm-svn: 322094
2018-01-09 17:26:06 +00:00
Serge Pavlov 9f0ac82f3b Added support for reading configuration files
Configuration file is read as a response file in which file names in
the nested constructs `@file` are resolved relative to the directory
where the including file resides. Lines in which the first non-whitespace
character is '#' are considered as comments and are skipped. Trailing
backslashes are used to concatenate lines in the same way as they
are used in shell scripts.

Differential Revision: https://reviews.llvm.org/D24926

llvm-svn: 321586
2017-12-30 15:37:46 +00:00
Serge Pavlov c15a438a21 Reverted 321580: Added support for reading configuration files
It caused buildbot fails.

llvm-svn: 321582
2017-12-30 09:15:59 +00:00
Serge Pavlov 0c1981ea0d Added support for reading configuration files
Configuration file is read as a response file in which file names in
the nested constructs `@file` are resolved relative to the directory
where the including file resides. Lines in which the first non-whitespace
character is '#' are considered as comments and are skipped. Trailing
backslashes are used to concatenate lines in the same way as they
are used in shell scripts.

Differential Revision: https://reviews.llvm.org/D24926

llvm-svn: 321580
2017-12-30 08:15:15 +00:00
Benjamin Kramer 3a13ed60ba Avoid int to string conversion in Twine or raw_ostream contexts.
Some output changes from uppercase hex to lowercase hex, no other functionality change intended.

llvm-svn: 321526
2017-12-28 16:58:54 +00:00
Rui Ueyama 6ec880d9b5 Improve performance TokenizeWindowsCommandLine
Patcy by Takuto Ikuta.

This patch reduces lld link time of chromium's blink_core.dll in
component build.

Total size of input argument in .directives become nearly 300MB in the
build and calling many strchr and assert becomes bottleneck.

On my desktop machine, 4 times stats of the link time are like below.
Improved around 10%.

This patch
TotalSeconds : 13.4918885
TotalSeconds : 13.9474257
TotalSeconds : 13.4941082
TotalSeconds : 13.6077962
Avg : 13.63530465

master
TotalSeconds : 15.6938531
TotalSeconds : 15.7022508
TotalSeconds : 15.9567202
TotalSeconds : 14.5851505
Avg : 15.48449365

Differential Revision: https://reviews.llvm.org/D41590

llvm-svn: 321479
2017-12-27 08:59:52 +00:00
Ben Dunbobbin bb534b15a9 [ThinLTO][CachePruning] explicitly disable pruning
In https://reviews.llvm.org/rL321077 and https://reviews.llvm.org/D41231 I fixed a regression in the c-api which prevented the pruning from being *effectively* disabled.

However this approach, helpfully recommended by @labath, is cleaner.
It is also nice to remove the weasel words about effectively disabling from the api comments.

Differential Revision: https://reviews.llvm.org/D41497

llvm-svn: 321376
2017-12-22 18:32:15 +00:00
Francis Visoiu Mistrih b2b961a3db [YAML] Fix UTF-8 handling
Previous YAML quoting patches broke UTF-8 printing in YAML: see https://reviews.llvm.org/D41290#961801.

Differential Revision: https://reviews.llvm.org/D41490

llvm-svn: 321283
2017-12-21 17:14:09 +00:00
Pavel Labath f13411ee98 [Support] Remove MemoryBuffer::getNewUninitMemBuffer
There is nothing useful that can be done with a read-only uninitialized
buffer without const_casting its contents to initialize it. A better
solution is to obtain a writable buffer
(WritableMemoryBuffer::getNewUninitMemBuffer), and then convert it to a
read-only buffer after initialization. All callers of this function have
already been updated to do this, so this function is now unused.

llvm-svn: 321257
2017-12-21 11:27:21 +00:00
Florian Hahn 3cfdaa30e2 [TargetParser] Check size before accessing architecture version.
Summary:
This fixes a crash when invalid -march options like `armv` are provided.

Based on a patch by Will Lovett.


Reviewers: rengolin, samparker, mcrosier

Reviewed By: samparker

Subscribers: aemerson, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D41429

llvm-svn: 321166
2017-12-20 11:32:43 +00:00
Adrian Prantl 0e6694d111 Silence a bunch of implicit fallthrough warnings
llvm-svn: 321114
2017-12-19 22:05:25 +00:00
Ben Dunbobbin 9ecb8b548c [Support][CachePruning] Disable cache pruning regression fix
borked by: rL284966 (see: https://reviews.llvm.org/D25730).

Previously, Interval was unsigned (see: CachePruning.h), replacing the type with std::chrono::seconds (which is signed) causes a regression in behaviour because the c-api intends negative values to translate to large positive intervals to *effectively* disable the pruning (see comments on: setCachePruningInterval()).

Differential Revision: https://reviews.llvm.org/D41231

llvm-svn: 321077
2017-12-19 14:42:38 +00:00
Pavel Labath 605636d872 [Support] Add WritableMemoryBuffer class
Summary:
The motivation here is LLDB, where we need to fixup relocations in
mmapped files before their contents can be read correctly.  The
MemoryBuffer class does exactly what we need, *except* that it maps the
file in read-only mode.

WritableMemoryBuffer reuses the existing machinery for opening and
mmapping a file. The only difference is in the argument to the
mapped_file_region constructor -- we create a private copy-on-write
mapping, so that we can make changes to the mapped data, but the changes
aren't carried over to the underlying file.

This patch is based on an initial version by Zachary Turner.

Reviewers: mehdi_amini, rnk, rafael, dblaikie, zturner

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D40291

llvm-svn: 321071
2017-12-19 12:15:50 +00:00