[NFC][Alignment] Use MaybeAlign in CGCleanup/CGExpr

[CodeGen] Store element type in DominatingValue<RValue>

For aggregate rvalues, we need to store the element type in the
dominating value, so we can recover the element type for the
address.

[CodeGen] Rename deprecated Address constructor

To make uses of the deprecated constructor easier to spot, and to
ensure that no new uses are introduced, rename it to
Address::deprecated().

While d

[CodeGen] Rename deprecated Address constructor

To make uses of the deprecated constructor easier to spot, and to
ensure that no new uses are introduced, rename it to
Address::deprecated().

While doing the rename, I've filled in element types in cases
where it was relatively obvious, but we're still left with 135
calls to the deprecated constructor.

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Skip exception cleanups when the innermost scope is EHTerminateScope.

EHTerminateScope is used to implement C++ noexcept semantics. Per C++
[except.terminate], it is implemented-defined whether no,

Skip exception cleanups when the innermost scope is EHTerminateScope.

EHTerminateScope is used to implement C++ noexcept semantics. Per C++
[except.terminate], it is implemented-defined whether no, some, or all
cleanups are run prior to terminatation.

Therefore, the code to run cleanups on the way towards termination is
unnecessary, and may be omitted.

After this change, we will still run some cleanups: any cleanups in a
function called from the noexcept function will continue to run, while
those in the noexcept function itself will not.

(Commit attempt 2: check InnermostEHScope != stable_end() before accessing it.)

Differential Revision: https://reviews.llvm.org/D113620

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Revert "Skip exception cleanups when the innermost scope is EHTerminateScope."

Breaks tests on some platforms. Reverting while investigating.

This reverts commit a4e255f9c6d4458fa6e70394af626f3b65e

Revert "Skip exception cleanups when the innermost scope is EHTerminateScope."

Breaks tests on some platforms. Reverting while investigating.

This reverts commit a4e255f9c6d4458fa6e70394af626f3b65e0a26d.

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Skip exception cleanups when the innermost scope is EHTerminateScope.

EHTerminateScope is used to implement C++ noexcept semantics. Per C++
[except.terminate], it is implemented-defined whether no,

Skip exception cleanups when the innermost scope is EHTerminateScope.

EHTerminateScope is used to implement C++ noexcept semantics. Per C++
[except.terminate], it is implemented-defined whether no, some, or all
cleanups are run prior to terminatation.

Therefore, the code to run cleanups on the way towards termination is
unnecessary, and may be omitted.

After this change, we will still run some cleanups: any cleanups in a
function called from the noexcept function will continue to run, while
those in the noexcept function itself will not.

Differential Revision: https://reviews.llvm.org/D113620

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[Windows SEH]: Fix -O2 crash for Windows -EHa

This patch fixes a Windows -EHa crash induced by previous commit 797ad701522988e212495285dade8efac41a24d4.
The crash was caused by "LifetimeMarker" scop

[Windows SEH]: Fix -O2 crash for Windows -EHa

This patch fixes a Windows -EHa crash induced by previous commit 797ad701522988e212495285dade8efac41a24d4.
The crash was caused by "LifetimeMarker" scope (with option -O2) that should not be considered as SEH Scope.

This change also turns off -fasync-exceptions by default under -EHa option for now.

Differential Revision: https://reviews.llvm.org/D103664#2799944

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[CodeGen] Avoid unused variable warning in Release builds. NFCI.

[Windows SEH]: HARDWARE EXCEPTION HANDLING (MSVC -EHa) - Part 1

This patch is the Part-1 (FE Clang) implementation of HW Exception handling.

This new feature adds the support of Hardware Exception

[Windows SEH]: HARDWARE EXCEPTION HANDLING (MSVC -EHa) - Part 1

This patch is the Part-1 (FE Clang) implementation of HW Exception handling.

This new feature adds the support of Hardware Exception for Microsoft Windows
SEH (Structured Exception Handling).
This is the first step of this project; only X86_64 target is enabled in this patch.

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 described below.

Two intrinsic are created to track CPP object scopes; eha_scope_begin() and eha_scope_end().
_scope_begin() is immediately added after ctor() is called and EHStack is pushed.
So it must be an invoke, not a call. With that it's also guaranteed an
EH-cleanup-pad is created regardless whether there exists a call in this scope.
_scope_end is added before dtor(). These two intrinsics make the computation of
Block-State possible in downstream code gen pass, even in the presence of
ctor/dtor inlining.

Two intrinsic, seh_try_begin() and seh_try_end(), are added for C-code to mark
_try boundary and to prevent from exceptions being moved across _try boundary.
All memory instructions inside a _try are considered as 'volatile' to assure
2nd and 3rd rules for C-code above. This is a little sub-optimized. But it's
acceptable as the amount of code directly under _try is very small.

Part-2 (will be in Part-2 patch): 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.html
https://lists.llvm.org/pipermail/llvm-dev/2020-April/141338.html

Differential Revision: https://reviews.llvm.org/D80344/new/

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[CodeGen] Simplify the way lifetime of block captures is extended

Rather than pushing inactive cleanups for the block captures at the
entry of a full expression and activating them during the creati

[CodeGen] Simplify the way lifetime of block captures is extended

Rather than pushing inactive cleanups for the block captures at the
entry of a full expression and activating them during the creation of
the block literal, just call pushLifetimeExtendedDestroy to ensure the
cleanups are popped at the end of the scope enclosing the block
expression.

rdar://problem/63996471

Differential Revision: https://reviews.llvm.org/D81624

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Fix clang test failures from D77454

[Windows SEH] Fix abnormal-exits in _try

Summary:
Per Windows SEH Spec, except _leave, all other early exits of a _try (goto/return/continue/break) are considered abnormal exits. In those cases, th

[Windows SEH] Fix abnormal-exits in _try

Summary:
Per Windows SEH Spec, except _leave, all other early exits of a _try (goto/return/continue/break) are considered abnormal exits. In those cases, the first parameter passes to its _finally funclet should be TRUE to indicate an abnormal-termination.

One way to implement abnormal exits in _try is to invoke Windows runtime _local_unwind() (MSVC approach) that will invoke _dtor funclet where abnormal-termination flag is always TRUE when calling _finally. Obviously this approach is less optimal and is complicated to implement in Clang.

Clang today has a NormalCleanupDestSlot mechanism to dispatch multiple exits at the end of _try. Since _leave (or try-end fall-through) is always Indexed with 0 in that NormalCleanupDestSlot, this fix takes the advantage of that mechanism and just passes NormalCleanupDest ID as 1st Arg to _finally.

Reviewers: rnk, eli.friedman, JosephTremoulet, asmith, efriedma

Reviewed By: efriedma

Subscribers: efriedma, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77936

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[clang codegen][opaque pointers] Remove use of deprecated constructor

(See also D76269.)

[Alignment][Clang][NFC] Add CharUnits::getAsAlign

Summary:
This is a prerequisite to removing `llvm::GlobalObject::setAlignment(unsigned)`.
This is patch is part of a series to introduce an Alignmen

[Alignment][Clang][NFC] Add CharUnits::getAsAlign

Summary:
This is a prerequisite to removing `llvm::GlobalObject::setAlignment(unsigned)`.
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: jholewinski, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68274

llvm-svn: 373592

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[Alignment][NFC] Remove LoadInst::setAlignment(unsigned)

Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-

[Alignment][NFC] Remove LoadInst::setAlignment(unsigned)

Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet, jdoerfert

Subscribers: hiraditya, asbirlea, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D68142

llvm-svn: 373195

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[NFC] avoid AlignedCharArray in clang

As discussed in D65249, don't use AlignedCharArray or std::aligned_storage. Just use alignas(X) char Buf[Size];. This will allow me to remove AlignedCharArray e

[NFC] avoid AlignedCharArray in clang

As discussed in D65249, don't use AlignedCharArray or std::aligned_storage. Just use alignas(X) char Buf[Size];. This will allow me to remove AlignedCharArray entirely, and works on the current minimum version of Visual Studio.

llvm-svn: 367274

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[opaque pointer types] Cleanup CGBuilder's Create*GEP.

The various EltSize, Offset, DataLayout, and StructLayout arguments
are all computable from the Address's element type and the DataLayout
which

[opaque pointer types] Cleanup CGBuilder's Create*GEP.

The various EltSize, Offset, DataLayout, and StructLayout arguments
are all computable from the Address's element type and the DataLayout
which the CGBuilder already has access to.

After having previously asserted that the computed values are the same
as those passed in, now remove the redundant arguments from
CGBuilder's Create*GEP functions.

Differential Revision: https://reviews.llvm.org/D57767

llvm-svn: 353629

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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 ne

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

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[TI removal] Make `getTerminator()` return a generic `Instruction`.

This removes the primary remaining API producing `TerminatorInst` which
will reduce the rate at which code is introduced trying to

[TI removal] Make `getTerminator()` return a generic `Instruction`.

This removes the primary remaining API producing `TerminatorInst` which
will reduce the rate at which code is introduced trying to use it and
generally make it much easier to remove the remaining APIs across the
codebase.

Also clean up some of the stragglers that the previous mechanical update
of variables missed.

Users of LLVM and out-of-tree code generally will need to update any
explicit variable types to handle this. Replacing `TerminatorInst` with
`Instruction` (or `auto`) almost always works. Most of these edits were
made in prior commits using the perl one-liner:
```
perl -i -ple 's/TerminatorInst(\b.* = .*getTerminator\(\))/Instruction\1/g'
```

This also my break some rare use cases where people overload for both
`Instruction` and `TerminatorInst`, but these should be easily fixed by
removing the `TerminatorInst` overload.

llvm-svn: 344504

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Remove trailing space

sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338291

Support lifetime-extension of conditional temporaries.

llvm-svn: 337767

Call CreateTempAllocaWithoutCast for ActiveFlag

This is partial re-commit of r332982.

llvm-svn: 334879

[WebAssembly] Use Windows EH instructions for Wasm EH

Summary:
Because wasm control flow needs to be structured, using WinEH
instructions to support wasm EH brings several benefits. This patch
makes

[WebAssembly] Use Windows EH instructions for Wasm EH

Summary:
Because wasm control flow needs to be structured, using WinEH
instructions to support wasm EH brings several benefits. This patch
makes wasm EH uses Windows EH instructions, with some changes:
1. Because wasm uses a single catch block to catch all C++ exceptions,
this merges all catch clauses into a single catchpad, within which we
test the EH selector as in Itanium EH.
2. Generates a call to `__clang_call_terminate` in case a cleanup
throws. Wasm does not have a runtime to handle this.
3. In case there is no catch-all clause, inserts a call to
`__cxa_rethrow` at the end of a catchpad in order to unwind to an
enclosing EH scope.

Reviewers: majnemer, dschuff

Subscribers: jfb, sbc100, jgravelle-google, sunfish, cfe-commits

Differential Revision: https://reviews.llvm.org/D44931

llvm-svn: 333703

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Revert r332982 Call CreateTempMemWithoutCast for ActiveFlag

Due to regression on arm.

llvm-svn: 332991

Call CreateTempMemWithoutCast for ActiveFlag

Introduced CreateMemTempWithoutCast and CreateTemporaryAllocaWithoutCast to emit alloca
without casting to default addr space.

ActiveFlag is a temporary

Call CreateTempMemWithoutCast for ActiveFlag

Introduced CreateMemTempWithoutCast and CreateTemporaryAllocaWithoutCast to emit alloca
without casting to default addr space.

ActiveFlag is a temporary variable emitted for clean up. It is defined as AllocaInst* type and there is
a cast to AlllocaInst in SetActiveFlag. An alloca casted to generic pointer causes assertion in
SetActiveFlag.

Since there is only load/store of ActiveFlag, it is safe to use the original alloca, therefore use
CreateMemTempWithoutCast is called.

Differential Revision: https://reviews.llvm.org/D47099

llvm-svn: 332982

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