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
This was allowing getelementptr with offsets, which doesn't make
sense. My initial attempt to use stripPointerCasts broke a few tests
involving aliases; add a new targeted verifier test for aliases.
This also provides the fix from D138537 for free, and also adds
support for addrspacecast (D138538) for free. Merge the tests in from
those.
I'm not really sure why findBaseObject exists; it seems redundant with
stripPointerCasts* (I'm also not really sure why getelementptrs are
allowed off of functions).
With D135642 ignoring unregistered symbols, isTransitiveUsedByMetadataOnly added
by D101512 is no longer needed (the operation is potentially slow). There is a
`.addrsig_sym` directive for an only-used-by-metadata symbol but it does not
emit an entry.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D138362
This patch is the Part-2 (BE LLVM) implementation of HW Exception handling.
Part-1 (FE Clang) was committed in 797ad70152.
This new feature adds the support of Hardware Exception for Microsoft Windows
SEH (Structured Exception Handling).
Compiler options:
For clang-cl.exe, the option is -EHa, the same as MSVC.
For clang.exe, the extra option is -fasync-exceptions,
plus -triple x86_64-windows -fexceptions and -fcxx-exceptions as usual.
NOTE:: Without the -EHa or -fasync-exceptions, this patch is a NO-DIFF change.
The rules for C code:
For C-code, one way (MSVC approach) to achieve SEH -EHa semantic is to follow three rules:
First, no exception can move in or out of _try region., i.e., no "potential faulty
instruction can be moved across _try boundary.
Second, the order of exceptions for instructions 'directly' under a _try must be preserved
(not applied to those in callees).
Finally, global states (local/global/heap variables) that can be read outside of _try region
must be updated in memory (not just in register) before the subsequent exception occurs.
The impact to C++ code:
Although SEH is a feature for C code, -EHa does have a profound effect on C++
side. When a C++ function (in the same compilation unit with option -EHa ) is
called by a SEH C function, a hardware exception occurs in C++ code can also
be handled properly by an upstream SEH _try-handler or a C++ catch(...).
As such, when that happens in the middle of an object's life scope, the dtor
must be invoked the same way as C++ Synchronous Exception during unwinding process.
Design:
A natural way to achieve the rules above in LLVM today is to allow an EH edge
added on memory/computation instruction (previous iload/istore idea) so that
exception path is modeled in Flow graph preciously. However, tracking every
single memory instruction and potential faulty instruction can create many
Invokes, complicate flow graph and possibly result in negative performance
impact for downstream optimization and code generation. Making all
optimizations be aware of the new semantic is also substantial.
This design does not intend to model exception path at instruction level.
Instead, the proposed design tracks and reports EH state at BLOCK-level to
reduce the complexity of flow graph and minimize the performance-impact on CPP
code under -EHa option.
One key element of this design is the ability to compute State number at
block-level. Our algorithm is based on the following rationales:
A _try scope is always a SEME (Single Entry Multiple Exits) region as jumping
into a _try is not allowed. The single entry must start with a seh_try_begin()
invoke with a correct State number that is the initial state of the SEME.
Through control-flow, state number is propagated into all blocks. Side exits
marked by seh_try_end() will unwind to parent state based on existing SEHUnwindMap[].
Note side exits can ONLY jump into parent scopes (lower state number).
Thus, when a block succeeds various states from its predecessors, the lowest
State triumphs others. If some exits flow to unreachable, propagation on those
paths terminate, not affecting remaining blocks.
For CPP code, object lifetime region is usually a SEME as SEH _try.
However there is one rare exception: jumping into a lifetime that has Dtor but
has no Ctor is warned, but allowed:
Warning: jump bypasses variable with a non-trivial destructor
In that case, the region is actually a MEME (multiple entry multiple exits).
Our solution is to inject a eha_scope_begin() invoke in the side entry block to
ensure a correct State.
Implementation:
Part-1: Clang implementation (already in):
Please see commit 797ad70152).
Part-2 : LLVM implementation described below.
For both C++ & C-code, the state of each block is computed at the same place in
BE (WinEHPreparing pass) where all other EH tables/maps are calculated.
In addition to _scope_begin & _scope_end, the computation of block state also
rely on the existing State tracking code (UnwindMap and InvokeStateMap).
For both C++ & C-code, the state of each block with potential trap instruction
is marked and reported in DAG Instruction Selection pass, the same place where
the state for -EHsc (synchronous exceptions) is done.
If the first instruction in a reported block scope can trap, a Nop is injected
before this instruction. This nop is needed to accommodate LLVM Windows EH
implementation, in which the address in IPToState table is offset by +1.
(note the purpose of that is to ensure the return address of a call is in the
same scope as the call address.
The handler for catch(...) for -EHa must handle HW exception. So it is
'adjective' flag is reset (it cannot be IsStdDotDot (0x40) that only catches
C++ exceptions).
Suppress push/popTerminate() scope (from noexcept/noTHrow) so that HW
exceptions can be passed through.
Original llvm-dev [RFC] discussions can be found in these two threads below:
https://lists.llvm.org/pipermail/llvm-dev/2020-March/140541.htmlhttps://lists.llvm.org/pipermail/llvm-dev/2020-April/141338.html
Differential Revision: https://reviews.llvm.org/D102817/new/
Currently the only way to do this is to work with the instruction list directly.
This is part of a series of cleanup patches towards making BasicBlock::getInstList() private.
Differential Revision: https://reviews.llvm.org/D139142
Currently the only way to do this is to work with the instruction list directly.
This is part of a series of cleanup patches towards making BasicBlock::getInstList() private.
Differential Revision: https://reviews.llvm.org/D138977
Currently the only way to do this is to work with the instruction list directly.
This is part of a series of cleanup patches towards making BasicBlock::getInstList() private.
Differential Revision: https://reviews.llvm.org/D138875
Clang and gcc both reject trying to use ifunc with a function which
doesn't return a pointer type. Some opaque pointer tests were using
this, apparently by accident.
Fix replaceVariableLocationOp unconditionally replacing the first operand of a
dbg.assign.
Reviewed By: jryans
Differential Revision: https://reviews.llvm.org/D138561
This patch replaces:
return Optional<T>();
with:
return None;
to make the migration from llvm::Optional to std::optional easier.
Specifically, I can deprecate None (in my source tree, that is) to
identify all the instances of None that should be replaced with
std::nullopt.
Note that "return None" far outnumbers "return Optional<T>();". There
are more than 2000 instances of "return None" in our source tree.
All of the instances in this patch come from functions that return
Optional<T> except Archive::findSym and ASTNodeImporter::import, where
we return Expected<Optional<T>>. Note that we can construct
Expected<Optional<T>> from any parameter convertible to Optional<T>,
which None certainly is.
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
Differential Revision: https://reviews.llvm.org/D138464
This diff splits out (from LLVMCore) IR printing passes into IRPrinter.
This structure is similar to what we already have for IRReader and
enables us to avoid circular dependencies between LLVMCore and Analysis
(this is a preparation for https://reviews.llvm.org/D137768).
The legacy interface is left unchanged, once the legacy pass manager
is removed (in the future) we will be able to clean it up further.
The bazel build configuration has been updated as well.
Test plan:
1/ Tested the following cmake configurations: static/dynamic linking * lld/gold * clang/gcc
2/ bazel build --config=generic_clang @llvm-project//...
Differential revision: https://reviews.llvm.org/D138081
This was trying to auto-upgrade a read_register call with missing type
mangling. This first would break since getCalledFunction checks the
callee type is consistent, so this would assert there. After that,
the replacement code would die on the type mismatch. Be more
defensive and let the verifier code produce an error that the IR
is broken.
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
This reverts commit bf8381a8bc.
There is a layering violation: LLVMAnalysis depends on LLVMCore, so
LLVMCore should not include LLVMAnalysis header
llvm/Analysis/ModuleSummaryAnalysis.h
Enable using -module-summary with -S
(similarly to what currently can be achieved with opt <input> -o - | llvm-dis).
This is a recommit of ef9e62469.
Test plan: ninja check-all
Differential revision: https://reviews.llvm.org/D137768
Enable using -module-summary with -S
(similarly to what currently can be achieved with opt <input> -o - | llvm-dis).
Test plan: ninja check-all
Differential revision: https://reviews.llvm.org/D137768
Fixes https://github.com/llvm/llvm-project/issues/56544
AsmWriter always writes ", ..." when a tail call has a varargs argument. This patch only writes the ", " when there is an argument before the varargs argument.
I did not write a dedicated test this for this change, but I modified an existing test that will test for a regression.
Reviewed By: avogelsgesang
Differential Revision: https://reviews.llvm.org/D137893
Signed-off-by: Adrian Vogelsgesang <avogelsgesang@salesforce.com>
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
Fangrui Song