Commit Graph

1492 Commits

Author SHA1 Message Date
Fangrui Song 89fae41ef1 [IR] llvm::Optional => std::optional
Many llvm/IR/* files have been migrated by other contributors.
This migrates most remaining files.
2022-12-05 04:13:11 +00:00
Krzysztof Parzyszek 0ca43d4488 DebugInfoMetadata: convert Optional to std::optional 2022-12-04 11:52:02 -06:00
Kazu Hirata e9e64f7c9e [Bitcode] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-02 20:36:05 -08:00
Kazu Hirata f960b935cc [Reader] Use std::optional in BitcodeReader.cpp (NFC)
This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-11-25 11:33:20 -08:00
Matt Arsenault 0d527e56a5 GlobalIFunc: Make ifunc respect function address spaces 2022-11-22 21:42:44 -05:00
Teresa Johnson 9eacbba290 Restore "[MemProf] ThinLTO summary support" with more fixes
This restores commit 98ed423361 and
follow on fix 00c22351ba, which were
reverted in 5d938eb6f7 due to an
MSVC bot failure. I've included a fix for that failure.

Differential Revision: https://reviews.llvm.org/D135714
2022-11-16 09:42:41 -08:00
Jeremy Morse 5d938eb6f7 Revert "Restore "[MemProf] ThinLTO summary support" with fixes"
This reverts commit 00c22351ba.
This reverts commit 98ed423361.

Seemingly MSVC has some kind of issue with this patch, in terms of linking:

  https://lab.llvm.org/buildbot/#/builders/123/builds/14137

I'll post more detail on D135714 momentarily.
2022-11-16 11:21:02 +00:00
Teresa Johnson 98ed423361 Restore "[MemProf] ThinLTO summary support" with fixes
This restores 4745945500, which was
reverted in commit 452a14efc8, along with
fixes for a couple of bot failures.
2022-11-15 08:55:17 -08:00
Teresa Johnson 452a14efc8 Revert "[MemProf] ThinLTO summary support"
This reverts commit 4745945500.

Revert while I try to fix a couple of non-Linux build failures.
2022-11-15 07:39:40 -08:00
Teresa Johnson 4745945500 [MemProf] ThinLTO summary support
Implements the ThinLTO summary support for memprof related metadata.

This includes support for the assembly format, and for building the
summary from IR during ModuleSummaryAnalysis.

To reduce space in both the bitcode format and the in memory index,
we do 2 things:
1. We keep a single vector of all uniq stack id hashes, and record the
   index into this vector in the callsite and allocation memprof
   summaries.
2. When building the combined index during the LTO link, the callsite
   and allocation memprof summaries are only kept on the FunctionSummary
   of the prevailing copy.

Differential Revision: https://reviews.llvm.org/D135714
2022-11-15 06:45:12 -08:00
Nikita Popov feda983ff8 [TableGen] Use MemoryEffects to represent intrinsic memory effects (NFCI)
The TableGen implementation was using a homegrown implementation of
FunctionModRefInfo. This switches it to use MemoryEffects instead.
This makes the code simpler, and will allow exposing the full
representational power of MemoryEffects in the future. Among other
things, this will allow us to map IntrHasSideEffects to an
inaccessiblemem readwrite, rather than just ignoring it entirely
in most cases.

To avoid layering issues, this moves the ModRef.h header from IR
to Support, so that it can be included in the TableGen layer.

Differential Revision: https://reviews.llvm.org/D137641
2022-11-14 10:52:04 +01:00
OCHyams a2620e00ff [Assignment Tracking][3/*] Add DIAssignID metadata boilerplate
The Assignment Tracking debug-info feature is outlined in this RFC:

https://discourse.llvm.org/t/
rfc-assignment-tracking-a-better-way-of-specifying-variable-locations-in-ir

Add the DIAssignID metadata attachment boilerplate. Includes a textual-bitcode
roundtrip test and tests that the verifier and parser catch badly formed IR.

This piece of metadata links together stores (used as an attachment) and the
yet-to-be-added llvm.dbg.assign debug intrinsic (used as an operand).

Reviewed By: jmorse

Differential Revision: https://reviews.llvm.org/D132222
2022-11-07 09:05:56 +00:00
Nikita Popov 304f1d59ca [IR] Switch everything to use memory attribute
This switches everything to use the memory attribute proposed in
https://discourse.llvm.org/t/rfc-unify-memory-effect-attributes/65579.
The old argmemonly, inaccessiblememonly and inaccessiblemem_or_argmemonly
attributes are dropped. The readnone, readonly and writeonly attributes
are restricted to parameters only.

The old attributes are auto-upgraded both in bitcode and IR.
The bitcode upgrade is a policy requirement that has to be retained
indefinitely. The IR upgrade is mainly there so it's not necessary
to update all tests using memory attributes in this patch, which
is already large enough. We could drop that part after migrating
tests, or retain it longer term, to make it easier to import IR
from older LLVM versions.

High-level Function/CallBase APIs like doesNotAccessMemory() or
setDoesNotAccessMemory() are mapped transparently to the memory
attribute. Code that directly manipulates attributes (e.g. via
AttributeList) on the other hand needs to switch to working with
the memory attribute instead.

Differential Revision: https://reviews.llvm.org/D135780
2022-11-04 10:21:38 +01:00
OCHyams fac26edae5 Revert "[Assignment Tracking][3/*] Add DIAssignID metadata boilerplate"
This reverts commit c285df77e9b78f971f9cd9d025248c20b030cc2a.

A sanitizer bot found an issue:
https://lab.llvm.org/buildbot/#/builders/5/builds/28809/steps/13/logs/stdio
2022-11-03 13:46:00 +00:00
OCHyams e53c4c6d86 [Assignment Tracking][3/*] Add DIAssignID metadata boilerplate
The Assignment Tracking debug-info feature is outlined in this RFC:

https://discourse.llvm.org/t/
rfc-assignment-tracking-a-better-way-of-specifying-variable-locations-in-ir

Add the DIAssignID metadata attachment boilerplate. Includes a textual-bitcode
roundtrip test and tests that the verifier and parser catch badly formed IR.

This piece of metadata links together stores (used as an attachment) and the
yet-to-be-added llvm.dbg.assign debug intrinsic (used as an operand).

Reviewed By: jmorse

Differential Revision: https://reviews.llvm.org/D132222
2022-11-03 11:24:18 +00:00
Nikita Popov e9754f0211 [IR] Add support for memory attribute
This implements IR and bitcode support for the memory attribute,
as specified in https://reviews.llvm.org/D135597.

The new attribute is not used for anything yet (and as such, the
old memory attributes are unaffected).

Differential Revision: https://reviews.llvm.org/D135592
2022-10-21 12:11:25 +02:00
Nikita Popov c028329787 [Bitcode] Remove redundant intrinsic remangling (NFCI)
UpgradeIntrinsicFunction() is supposed to handle this already.
2022-10-21 11:50:09 +02:00
Teresa Johnson 646e25d051 [BitcodeReader] Convert pair to triple in preparation for MemProf (NFC)
Extracted from D135714 which adds summary support for MemProf. We will
need a 3rd tuple member in the ValueIdToValueInfoMap, this patch makes a
number of NFC changes to the existing clients of that map to reflect the
conversion of pair to tuple.
2022-10-19 13:34:30 -07:00
Ben Dunbobbin 7eee2a2d44 [IR] Don't allow DLL storage-class and local linkage
Disallow this meaningless combination. Doing so simplifies analysis
of LLVM code w.r.t t DLL storage-class, and prevents mistakes with
DLL storage class.

- Change the assembler to reject DLL storage class on symbols with
  local linkage.
- Change the bitcode reader to clear the DLL Storage class when the
  linkage is local for auto-upgrading
- Update LangRef.

There is an existing restriction on non-default visibility and local
linkage which this is modelled on.

Differential Review: https://reviews.llvm.org/D134784
2022-09-30 00:26:01 +01:00
Nikita Popov 96cb7c2273 [ConstantExpr] Remove fneg expression
As part of https://discourse.llvm.org/t/rfc-remove-most-constant-expressions/63179,
this removes the fneg constant expression (which is, incidentally,
the only unary operator expression).

Differential Revision: https://reviews.llvm.org/D133418
2022-09-08 10:24:55 +02:00
Nikita Popov d452d5e2de [Bitcode] Fix constexpr autoupgrade for arrays and structs
While vectors use insertelement, structs and arrays should use
insertvalue.
2022-09-07 12:47:21 +02:00
Kazu Hirata 258531b7ac Remove redundant initialization of Optional (NFC) 2022-08-20 21:18:28 -07:00
Fangrui Song de9d80c1c5 [llvm] LLVM_FALLTHROUGH => [[fallthrough]]. NFC
With C++17 there is no Clang pedantic warning or MSVC C5051.
2022-08-08 11:24:15 -07:00
Kazu Hirata a2d4501718 [llvm] Fix comment typos (NFC) 2022-08-07 00:16:14 -07:00
Ellis Hoag 12e78ff881 [InstrProf] Add the skipprofile attribute
As discussed in [0], this diff adds the `skipprofile` attribute to
prevent the function from being profiled while allowing profiled
functions to be inlined into it. The `noprofile` attribute remains
unchanged.

The `noprofile` attribute is used for functions where it is
dangerous to add instrumentation to while the `skipprofile` attribute is
used to reduce code size or performance overhead.

[0] https://discourse.llvm.org/t/why-does-the-noprofile-attribute-restrict-inlining/64108

Reviewed By: phosek

Differential Revision: https://reviews.llvm.org/D130807
2022-08-04 08:45:27 -07:00
Nuno Lopes fffabd5348 [NFC] Switch a few uses of undef to poison as placeholders for unreachable code 2022-07-30 13:55:56 +01:00
Arthur Eubanks 2eade1dba4 [WPD] Use new llvm.public.type.test intrinsic for potentially publicly visible classes
Turning on opaque pointers has uncovered an issue with WPD where we currently pattern match away `assume(type.test)` in WPD so that a later LTT doesn't resolve the type test to undef and introduce an `assume(false)`. The pattern matching can fail in cases where we transform two `assume(type.test)`s into `assume(phi(type.test.1, type.test.2))`.

Currently we create `assume(type.test)` for all virtual calls that might be devirtualized. This is to support `-Wl,--lto-whole-program-visibility`.

To prevent this, all virtual calls that may not be in the same LTO module instead use a new `llvm.public.type.test` intrinsic in place of the `llvm.type.test`. Then when we know if `-Wl,--lto-whole-program-visibility` is passed or not, we can either replace all `llvm.public.type.test` with `llvm.type.test`, or replace all `llvm.public.type.test` with `true`. This prevents WPD from trying to pattern match away `assume(type.test)` for public virtual calls when failing the pattern matching will result in miscompiles.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D128955
2022-07-26 08:01:08 -07:00
Kazu Hirata 3112987d5c Remove unused forward declarations (NFC) 2022-07-17 15:37:48 -07:00
Nikita Popov 2a721374ae [IR] Don't use blockaddresses as callbr arguments
Following some recent discussions, this changes the representation
of callbrs in IR. The current blockaddress arguments are replaced
with `!` label constraints that refer directly to callbr indirect
destinations:

    ; Before:
    %res = callbr i8* asm "", "=r,r,i"(i8* %x, i8* blockaddress(@test8, %foo))
    to label %asm.fallthrough [label %foo]
    ; After:
    %res = callbr i8* asm "", "=r,r,!i"(i8* %x)
    to label %asm.fallthrough [label %foo]

The benefit of this is that we can easily update the successors of
a callbr, without having to worry about also updating blockaddress
references. This should allow us to remove some limitations:

* Allow unrolling/peeling/rotation of callbr, or any other
  clone-based optimizations
  (https://github.com/llvm/llvm-project/issues/41834)
* Allow duplicate successors
  (https://github.com/llvm/llvm-project/issues/45248)

This is just the IR representation change though, I will follow up
with patches to remove limtations in various transformation passes
that are no longer needed.

Differential Revision: https://reviews.llvm.org/D129288
2022-07-15 10:18:17 +02:00
Nikita Popov 159feac1c0 [Bitcode] Report metadata decoding error more gracefully 2022-07-14 16:50:33 +02:00
Mitch Phillips 90e5a8ac47 Remove 'no_sanitize_memtag'. Add 'sanitize_memtag'.
For MTE globals, we should have clang emit the attribute for all GV's
that it creates, and then use that in the upcoming AArch64 global
tagging IR pass. We need a positive attribute for this sanitizer (rather
than implicit sanitization of all globals) because it needs to interact
with other parts of LLVM, including:

  1. Suppressing certain global optimisations (like merging),
  2. Emitting extra directives by the ASM writer, and
  3. Putting extra information in the symbol table entries.

While this does technically make the LLVM IR / bitcode format
non-backwards-compatible, nobody should have used this attribute yet,
because it's a no-op.

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D128950
2022-07-13 08:54:41 -07:00
Nick Desaulniers 2240d72f15 [X86] initial -mfunction-return=thunk-extern support
Adds support for:
* `-mfunction-return=<value>` command line flag, and
* `__attribute__((function_return("<value>")))` function attribute

Where the supported <value>s are:
* keep (disable)
* thunk-extern (enable)

thunk-extern enables clang to change ret instructions into jmps to an
external symbol named __x86_return_thunk, implemented as a new
MachineFunctionPass named "x86-return-thunks", keyed off the new IR
attribute fn_ret_thunk_extern.

The symbol __x86_return_thunk is expected to be provided by the runtime
the compiled code is linked against and is not defined by the compiler.
Enabling this option alone doesn't provide mitigations without
corresponding definitions of __x86_return_thunk!

This new MachineFunctionPass is very similar to "x86-lvi-ret".

The <value>s "thunk" and "thunk-inline" are currently unsupported. It's
not clear yet that they are necessary: whether the thunk pattern they
would emit is beneficial or used anywhere.

Should the <value>s "thunk" and "thunk-inline" become necessary,
x86-return-thunks could probably be merged into x86-retpoline-thunks
which has pre-existing machinery for emitting thunks (which could be
used to implement the <value> "thunk").

Has been found to build+boot with corresponding Linux
kernel patches. This helps the Linux kernel mitigate RETBLEED.
* CVE-2022-23816
* CVE-2022-28693
* CVE-2022-29901

See also:
* "RETBLEED: Arbitrary Speculative Code Execution with Return
Instructions."
* AMD SECURITY NOTICE AMD-SN-1037: AMD CPU Branch Type Confusion
* TECHNICAL GUIDANCE FOR MITIGATING BRANCH TYPE CONFUSION REVISION 1.0
  2022-07-12
* Return Stack Buffer Underflow / Return Stack Buffer Underflow /
  CVE-2022-29901, CVE-2022-28693 / INTEL-SA-00702

SystemZ may eventually want to support "thunk-extern" and "thunk"; both
options are used by the Linux kernel's CONFIG_EXPOLINE.

This functionality has been available in GCC since the 8.1 release, and
was backported to the 7.3 release.

Many thanks for folks that provided discrete review off list due to the
embargoed nature of this hardware vulnerability. Many Bothans died to
bring us this information.

Link: https://www.youtube.com/watch?v=IF6HbCKQHK8
Link: https://github.com/llvm/llvm-project/issues/54404
Link: https://gcc.gnu.org/legacy-ml/gcc-patches/2018-01/msg01197.html
Link: https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/advisory-guidance/return-stack-buffer-underflow.html
Link: https://arstechnica.com/information-technology/2022/07/intel-and-amd-cpus-vulnerable-to-a-new-speculative-execution-attack/?comments=1
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ce114c866860aa9eae3f50974efc68241186ba60
Link: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00702.html
Link: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00707.html

Reviewed By: aaron.ballman, craig.topper

Differential Revision: https://reviews.llvm.org/D129572
2022-07-12 09:17:54 -07:00
Nicolai Hähnle ede600377c ManagedStatic: remove many straightforward uses in llvm
(Reapply after revert in e9ce1a5880 due to
Fuchsia test failures. Removed changes in lib/ExecutionEngine/ other
than error categories, to be checked in more detail and reapplied
separately.)

Bulk remove many of the more trivial uses of ManagedStatic in the llvm
directory, either by defining a new getter function or, in many cases,
moving the static variable directly into the only function that uses it.

Differential Revision: https://reviews.llvm.org/D129120
2022-07-10 10:29:15 +02:00
Nicolai Hähnle e9ce1a5880 Revert "ManagedStatic: remove many straightforward uses in llvm"
This reverts commit e6f1f06245.

Reverting due to a failure on the fuchsia-x86_64-linux buildbot.
2022-07-10 09:54:30 +02:00
Nicolai Hähnle e6f1f06245 ManagedStatic: remove many straightforward uses in llvm
Bulk remove many of the more trivial uses of ManagedStatic in the llvm
directory, either by defining a new getter function or, in many cases,
moving the static variable directly into the only function that uses it.

Differential Revision: https://reviews.llvm.org/D129120
2022-07-10 09:15:08 +02:00
Shilei Tian 1023ddaf77 [LLVM] Add the support for fmax and fmin in atomicrmw instruction
This patch adds the support for `fmax` and `fmin` operations in `atomicrmw`
instruction. For now (at least in this patch), the instruction will be expanded
to CAS loop. There are already a couple of targets supporting the feature. I'll
create another patch(es) to enable them accordingly.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D127041
2022-07-06 10:57:53 -04:00
Nikita Popov 11950efe06 [ConstExpr] Remove div/rem constant expressions
D128820 stopped creating div/rem constant expressions by default;
this patch removes support for them entirely.

The getUDiv(), getExactUDiv(), getSDiv(), getExactSDiv(), getURem()
and getSRem() on ConstantExpr are removed, and ConstantExpr::get()
now only accepts binary operators for which
ConstantExpr::isSupportedBinOp() returns true. Uses of these methods
may be replaced either by corresponding IRBuilder methods, or
ConstantFoldBinaryOpOperands (if a constant result is required).

On the C API side, LLVMConstUDiv, LLVMConstExactUDiv, LLVMConstSDiv,
LLVMConstExactSDiv, LLVMConstURem and LLVMConstSRem are removed and
corresponding LLVMBuild methods should be used.

Importantly, this also means that constant expressions can no longer
trap! This patch still keeps the canTrap() method to minimize diff --
I plan to drop it in a separate NFC patch.

Differential Revision: https://reviews.llvm.org/D129148
2022-07-06 10:11:34 +02:00
Fangrui Song 67854f9ed0 Use value_or instead of getValueOr. NFC 2022-06-29 21:55:02 -07:00
Nikita Popov 1271b8f57a [Bitcode] Restore bitcast expression auto-upgrade
Restore the autoupgrade from bitcast to ptrtoint+inttoptr, which
was lost as part of D127729.

This fixes the backwards compatibility issue noted in:
https://reviews.llvm.org/D127729#inline-1236519
2022-06-29 14:35:56 +02:00
Nikita Popov f5bab24afe [ValueList] Include Error.h (NFC)
Hopefully fixes clang-ppc64-aix. Apparently std::function can't
be instantiated with a forward declared type in some environments.
2022-06-28 13:26:20 +02:00
Nikita Popov 941c8e0ea5 [Bitcode] Support expanding constant expressions into instructions
This implements an autoupgrade from constant expressions to
instructions, which is needed for
https://discourse.llvm.org/t/rfc-remove-most-constant-expressions/63179.

The basic approach is that constant expressions (CST_CODE_CE_*
records) now initially only create a BitcodeConstant value that
holds opcode, flags and operands IDs. Then, when the value actually
gets used, it can be converted either into a constant expression
(if that expression type is still supported) or into a sequence of
instructions. As currently all expressions are still supported,
-expand-constant-exprs is added for testing purposes, to force
expansion.

PHI nodes require special handling, because the constant expression
needs to be evaluated on the incoming edge. We do this by putting
it into a temporary block and then wiring it up appropriately
afterwards (for non-critical edges, we could also move the
instructions into the predecessor).

This also removes the need for the forward referenced constants
machinery, as the BitcodeConstants only hold value IDs. At the
point where the value is actually materialized, no forward
references are needed anymore.

Differential Revision: https://reviews.llvm.org/D127729
2022-06-28 11:09:46 +02:00
Kazu Hirata 7a47ee51a1 [llvm] Don't use Optional::getValue (NFC) 2022-06-20 22:45:45 -07:00
Kazu Hirata 0916d96d12 Don't use Optional::hasValue (NFC) 2022-06-20 20:17:57 -07:00
Nikita Popov 7cc4d4497c [BitcodeReader] Remove unnecessary argument defaults (NFC)
This is an internal method that is always called with all arguments.
2022-06-15 13:24:13 +02:00
Chuanqi Xu 735e6c40b5 [Coroutines] Convert coroutine.presplit to enum attr
This is required by @nikic in https://reviews.llvm.org/D127383 to
decrease the cost to check whether a function is a coroutine and this
fixes a FIXME too.

Reviewed By: rjmccall, ezhulenev

Differential Revision: https://reviews.llvm.org/D127471
2022-06-14 14:23:46 +08:00
Vitaly Buka 665617182c [Bitcode] Don't use UINT_MAX for missing SanitizerMetadata
Looks like comment on D126100 was unnoticed.
2022-06-10 18:20:55 -07:00
Mitch Phillips 8db981d463 Add sanitizer-specific GlobalValue attributes.
Plan is the migrate the global variable metadata for sanitizers, that's
currently carried around generally in the 'llvm.asan.globals' section,
onto the global variable itself.

This patch adds the attribute and plumbs it through the LLVM IR and
bitcode formats, but is a no-op other than that so far.

Reviewed By: vitalybuka, kstoimenov

Differential Revision: https://reviews.llvm.org/D126100
2022-06-10 12:28:18 -07:00
Augie Fackler 42861faa8e attributes: introduce allockind attr for describing allocator fn behavior
I chose to encode the allockind information in a string constant because
otherwise we would get a bit of an explosion of keywords to deal with
the possible permutations of allocation function types.

I'm not sure that CodeGen.h is the correct place for this enum, but it
seemed to kind of match the UWTableKind enum so I put it in the same
place. Constructive suggestions on a better location most certainly
encouraged.

Differential Revision: https://reviews.llvm.org/D123088
2022-05-31 10:01:17 -04:00
Ahmed Bougacha 362b4066f0 [ObjCARC] Drop nullary clang.arc.attachedcall bundles in autoupgrade.
In certain use-cases, these can be emitted by old compilers, but the
operand is now always required.  These are only used for optimizations,
so it's safe to drop them if they happen to have the now-invalid format.
The semantically-required call is already a separate instruction.

Differential Revision: https://reviews.llvm.org/D123811
2022-05-20 15:27:29 -07:00
Arthur Eubanks 470910c4ad [OpaquePtr][BitcodeReader] Explicitly turn off opaque pointers if we see a typed pointer
Followup to D125735 on the bitcode reader side.

Reviewed By: #opaque-pointers, nikic

Differential Revision: https://reviews.llvm.org/D125736
2022-05-17 08:43:02 -07:00