[FPEnv] Allow CompoundStmt to keep FP options

This is a recommit of b822efc7404bf09ccfdc1ab7657475026966c3b2,
reverted in dc34d8df4c48b3a8f474360970cae8a58e6c84f0. The commit caused
fails because th

[FPEnv] Allow CompoundStmt to keep FP options

This is a recommit of b822efc7404bf09ccfdc1ab7657475026966c3b2,
reverted in dc34d8df4c48b3a8f474360970cae8a58e6c84f0. The commit caused
fails because the test ast-print-fp-pragmas.c did not specify particular
target, and it failed on targets which do not support constrained
intrinsics. The original commit message is below.

AST does not have special nodes for pragmas. Instead a pragma modifies
some state variables of Sema, which in turn results in modified
attributes of AST nodes. This technique applies to floating point
operations as well. Every AST node that can depend on FP options keeps
current set of them.

This technique works well for options like exception behavior or fast
math options. They represent instructions to the compiler how to modify
code generation for the affected nodes. However treatment of FP control
modes has problems with this technique. Modifying FP control mode
(like rounding direction) usually requires operations on hardware, like
writing to control registers. It must be done prior to the first
operation that depends on the control mode. In particular, such
operations are required for implementation of `pragma STDC FENV_ROUND`,
compiler should set up necessary rounding direction at the beginning of
compound statement where the pragma occurs. As there is no representation
for pragmas in AST, the code generation becomes a complicated task in
this case.

To solve this issue FP options are kept inside CompoundStmt. Unlike to FP
options in expressions, these does not affect any operation on FP values,
but only inform the codegen about the FP options that act in the body of
the statement. As all pragmas that modify FP environment may occurs only
at the start of compound statement or at global level, such solution
works for all relevant pragmas. The options are kept as a difference
from the options in the enclosing compound statement or default options,
it helps codegen to set only changed control modes.

Differential Revision: https://reviews.llvm.org/D123952

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Revert "[FPEnv] Allow CompoundStmt to keep FP options"

On some buildbots test `ast-print-fp-pragmas.c` fails, need to investigate it.

This reverts commit 0401fd12d4aa0553347fe34d666fb236d8719173.
T

Revert "[FPEnv] Allow CompoundStmt to keep FP options"

On some buildbots test `ast-print-fp-pragmas.c` fails, need to investigate it.

This reverts commit 0401fd12d4aa0553347fe34d666fb236d8719173.
This reverts commit b822efc7404bf09ccfdc1ab7657475026966c3b2.

show more ...

[FPEnv] Allow CompoundStmt to keep FP options

AST does not have special nodes for pragmas. Instead a pragma modifies
some state variables of Sema, which in turn results in modified
attributes of AST

[FPEnv] Allow CompoundStmt to keep FP options

AST does not have special nodes for pragmas. Instead a pragma modifies
some state variables of Sema, which in turn results in modified
attributes of AST nodes. This technique applies to floating point
operations as well. Every AST node that can depend on FP options keeps
current set of them.

This technique works well for options like exception behavior or fast
math options. They represent instructions to the compiler how to modify
code generation for the affected nodes. However treatment of FP control
modes has problems with this technique. Modifying FP control mode
(like rounding direction) usually requires operations on hardware, like
writing to control registers. It must be done prior to the first
operation that depends on the control mode. In particular, such
operations are required for implementation of `pragma STDC FENV_ROUND`,
compiler should set up necessary rounding direction at the beginning of
compound statement where the pragma occurs. As there is no representation
for pragmas in AST, the code generation becomes a complicated task in
this case.

To solve this issue FP options are kept inside CompoundStmt. Unlike to FP
options in expressions, these does not affect any operation on FP values,
but only inform the codegen about the FP options that act in the body of
the statement. As all pragmas that modify FP environment may occurs only
at the start of compound statement or at global level, such solution
works for all relevant pragmas. The options are kept as a difference
from the options in the enclosing compound statement or default options,
it helps codegen to set only changed control modes.

Differential Revision: https://reviews.llvm.org/D123952

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[JSONNodeDumper] Do not print mangled names for local variables (PR49111)

Mangled names are not meaningful for variables with local storage,
and may not be well defined (getting the mangled name for

[JSONNodeDumper] Do not print mangled names for local variables (PR49111)

Mangled names are not meaningful for variables with local storage,
and may not be well defined (getting the mangled name for VLA
crashes the mangler). As such, do not include them in the JSON
dump.

This allows running update_cc_test_checks on some OpenMP tests again.

Fixes https://github.com/llvm/llvm-project/issues/49111.

Differential Revision: https://reviews.llvm.org/D116169

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Implement if consteval (P1938)

Modify the IfStmt node to suppoort constant evaluated expressions.

Add a new ExpressionEvaluationContext::ImmediateFunctionContext to
keep track of immediate function

Implement if consteval (P1938)

Modify the IfStmt node to suppoort constant evaluated expressions.

Add a new ExpressionEvaluationContext::ImmediateFunctionContext to
keep track of immediate function contexts.

This proved easier/better/probably more efficient than walking the AST
backward as it allows diagnosing nested if consteval statements.

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Add dumping support for RequiresExpr.

In passing, fix an ast-print bug that inserted a spurious extra `;`
after a concept definition.

[clang] NFC: Rename rvalue to prvalue

This renames the expression value categories from rvalue to prvalue,
keeping nomenclature consistent with C++11 onwards.

C++ has the most complicated taxonomy

[clang] NFC: Rename rvalue to prvalue

This renames the expression value categories from rvalue to prvalue,
keeping nomenclature consistent with C++11 onwards.

C++ has the most complicated taxonomy here, and every other language
only uses a subset of it, so it's less confusing to use the C++ names
consistently, and mentally remap to the C names when working on that
context (prvalue -> rvalue, no xvalues, etc).

Renames:
* VK_RValue -> VK_PRValue
* Expr::isRValue -> Expr::isPRValue
* SK_QualificationConversionRValue -> SK_QualificationConversionPRValue
* JSON AST Dumper Expression nodes value category: "rvalue" -> "prvalue"

Signed-off-by: Matheus Izvekov <[email protected]>

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D103720

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JSONNodeDumper.cpp - VisitIntegerLiteral - avoid APSInt::toString std::string wrapper. NFCI

Pulled out of D103888 - use the underlying SmallString version directly

[clang] p1099 using enum part 2

This implements the 'using enum maybe-qualified-enum-tag ;' part of
1099. It introduces a new 'UsingEnumDecl', subclassed from
'BaseUsingDecl'. Much of the diff is th

[clang] p1099 using enum part 2

This implements the 'using enum maybe-qualified-enum-tag ;' part of
1099. It introduces a new 'UsingEnumDecl', subclassed from
'BaseUsingDecl'. Much of the diff is the boilerplate needed to get the
new class set up.

There is one case where we accept ill-formed, but I believe this is
merely an extended case of an existing bug, so consider it
orthogonal. AFAICT in class-scope the c++20 rule is that no 2 using
decls can bring in the same target decl ([namespace.udecl]/8). But we
already accept:

struct A { enum { a }; };
struct B : A { using A::a; };
struct C : B { using A::a;
using B::a; }; // same enumerator

this patch permits mixtures of 'using enum Bob;' and 'using Bob::member;' in the same way.

Differential Revision: https://reviews.llvm.org/D102241

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Reimplement __builtin_unique_stable_name-

The original version of this was reverted, and @rjmcall provided some
advice to architect a new solution. This is that solution.

This implements a builtin

Reimplement __builtin_unique_stable_name-

The original version of this was reverted, and @rjmcall provided some
advice to architect a new solution. This is that solution.

This implements a builtin to provide a unique name that is stable across
compilations of this TU for the purposes of implementing the library
component of the unnamed kernel feature of SYCL. It does this by
running the Itanium mangler with a few modifications.

Because it is somewhat common to wrap non-kernel-related lambdas in
macros that aren't present on the device (such as for logging), this
uniquely generates an ID for all lambdas involved in the naming of a
kernel. It uses the lambda-mangling number to do this, except replaces
this with its own number (starting at 10000 for readabililty reasons)
for lambdas used to name a kernel.

Additionally, this implements itself as constexpr with a slight catch:
if a name would be invalidated by the use of this lambda in a later
kernel invocation, it is diagnosed as an error (see the Sema tests).

Differential Revision: https://reviews.llvm.org/D103112

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[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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Fix null ptr crash dumping TemplateTemplateParmDecl

The following program winds up with
D->getDefaultArgStorage().getInheritedFrom() == nullptr
during dumping the TemplateTemplateParmDecl correspond

Fix null ptr crash dumping TemplateTemplateParmDecl

The following program winds up with
D->getDefaultArgStorage().getInheritedFrom() == nullptr
during dumping the TemplateTemplateParmDecl corresponding to the
template parameter of i.

template <typename>
struct R;
template <template <typename> class = R>
void i();

This patch fixes the null pointer dereference.

show more ...

Revert "[NFC, Refactor] Modernize StorageClass from Specifiers.h to a scoped enum (II)"

This reverts commit efc82c4ad2bcb256a4f4c20238d08cd3afba4d2d.

[NFC, Refactor] Modernize StorageClass from Specifiers.h to a scoped enum (II)

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D93765

[clang][NFC] Use SmallString instead of SmallVector<char

Simplifies code in some places and is more explicit about what is being used.
No additional includes were added here so no impact on compile

[clang][NFC] Use SmallString instead of SmallVector<char

Simplifies code in some places and is more explicit about what is being used.
No additional includes were added here so no impact on compile time.

show more ...

[Sema][AArch64] Support arm_sve_vector_bits attribute

This patch implements the semantics for the 'arm_sve_vector_bits' type
attribute, defined by the Arm C Language Extensions (ACLE) for SVE [1].
T

[Sema][AArch64] Support arm_sve_vector_bits attribute

This patch implements the semantics for the 'arm_sve_vector_bits' type
attribute, defined by the Arm C Language Extensions (ACLE) for SVE [1].
The purpose of this attribute is to define vector-length-specific (VLS)
versions of existing vector-length-agnostic (VLA) types.

The semantics were already implemented by D83551, although the
implementation approach has since changed to represent VLSTs as
VectorType in the AST and fixed-length vectors in the IR everywhere
except in function args/returns. This is described in the prototype
patch D85128 demonstrating the new approach.

The semantic changes added in D83551 are changed since the
AttributedType is replaced by VectorType in the AST. Minimal changes
were necessary in the previous patch as the canonical type for both VLA
and VLS was the same (i.e. sizeless), except in constructs such as
globals and structs where sizeless types are unsupported. This patch
reverts the changes that permitted VLS types that were represented as
sizeless types in such circumstances, and adds support for implicit
casting between VLA <-> VLS types as described in section 3.7.3.2 of the
ACLE.

Since the SVE builtin types for bool and uint8 are both represented as
BuiltinType::UChar in VLSTs, two new vector kinds are implemented to
distinguish predicate and data vectors.

[1] https://developer.arm.com/documentation/100987/latest

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D85736

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[clang] Rework how and when APValues are dumped

Currently APValues are dumped as a single string. This becomes quickly
completely unreadable since APValue is a tree-like structure. Even a simple
exa

[clang] Rework how and when APValues are dumped

Currently APValues are dumped as a single string. This becomes quickly
completely unreadable since APValue is a tree-like structure. Even a simple
example is not pretty:

struct S { int arr[4]; float f; };
constexpr S s = { .arr = {1,2}, .f = 3.1415f };
// Struct fields: Array: Int: 1, Int: 2, 2 x Int: 0, Float: 3.141500e+00

With this patch this becomes:

-Struct
|-field: Array size=4
| |-elements: Int 1, Int 2
| `-filler: 2 x Int 0
`-field: Float 3.141500e+00

Additionally APValues are currently only dumped as part of visiting a
ConstantExpr. This patch also dump the value of the initializer of constexpr
variable declarations:

constexpr int foo(int a, int b) { return a + b - 42; }
constexpr int a = 1, b = 2;
constexpr int c = foo(a, b) > 0 ? foo(a, b) : foo(b, a);
// VarDecl 0x62100008aec8 <col:3, col:57> col:17 c 'const int' constexpr cinit
// |-value: Int -39
// `-ConditionalOperator 0x62100008b4d0 <col:21, col:57> 'int'
// <snip>

Do the above by moving the dump functions to TextNodeDumper which already has
the machinery to display trees. The cases APValue::LValue, APValue::MemberPointer
and APValue::AddrLabelDiff are left as they were before (unimplemented).

We try to display multiple elements on the same line if they are considered to
be "simple". This is to avoid wasting large amounts of vertical space in an
example like:

constexpr int arr[8] = {0,1,2,3,4,5,6,7};
// VarDecl 0x62100008bb78 <col:3, col:42> col:17 arr 'int const[8]' constexpr cinit
// |-value: Array size=8
// | |-elements: Int 0, Int 1, Int 2, Int 3
// | `-elements: Int 4, Int 5, Int 6, Int 7

Differential Revision: https://reviews.llvm.org/D83183

Reviewed By: aaron.ballman

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[AST] Dump containsErrors bit for the Type.

Reviewers: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D81912

[clang] Rename Decl::isHidden() to isUnconditionallyVisible().

Also invert the sense of the return value.

As pointed out by the FIXME that this change resolves, isHidden() wasn't
a very accurate na

[clang] Rename Decl::isHidden() to isUnconditionallyVisible().

Also invert the sense of the return value.

As pointed out by the FIXME that this change resolves, isHidden() wasn't
a very accurate name for this function.

I haven't yet changed any of the strings that are output in
ASTDumper.cpp / JSONNodeDumper.cpp / TextNodeDumper.cpp in response to
whether isHidden() is set because

a) I'm not sure whether it's actually desired to change these strings
(would appreciate feedback on this), and

b) In any case, I'd like to get this pure rename out of the way first,
without any changes to tests. Changing the strings that are output in
the various ...Dumper.cpp files will require changes to quite a few
tests, and I'd like to make those in a separate change.

Differential Revision: https://reviews.llvm.org/D81392

Reviewed By: rsmith

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[clang][NFC] Generate the {Type,ArrayType,UnaryExprOrType,Expression}Traits...

...enumerations from TokenKinds.def and use the new macros from TokenKinds.def
to remove the hard-coded lists of traits

[clang][NFC] Generate the {Type,ArrayType,UnaryExprOrType,Expression}Traits...

...enumerations from TokenKinds.def and use the new macros from TokenKinds.def
to remove the hard-coded lists of traits.

All the information needed to generate these enumerations is already present
in TokenKinds.def. The motivation here is to be able to dump the trait spelling
without hard-coding the list in yet another place.

Note that this change the order of the enumerators in the enumerations (except
that in the TypeTrait enumeration all unary type traits are before all binary
type traits, and all binary type traits are before all n-ary type traits).

Apart from the aforementioned ordering which is relied upon, after this patch
no code in clang or in the various clang tools depend on the specific ordering
of the enumerators.

No functional changes intended.

Differential Revision: https://reviews.llvm.org/D81455

Reviewed By: aaron.ballman

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PR46209: properly determine whether a copy assignment operator is
trivial.

We previously took a shortcut by assuming that if a subobject had a
trivial copy assignment operator (with a few side-condi

PR46209: properly determine whether a copy assignment operator is
trivial.

We previously took a shortcut by assuming that if a subobject had a
trivial copy assignment operator (with a few side-conditions), we would
always invoke it, and could avoid going through overload resolution.
That turns out to not be correct in the presenve of ref-qualifiers (and
also won't be the case for copy-assignments with requires-clauses
either). Use the same logic for lazy declaration of copy-assignments
that we use for all other special member functions.

Previously committed as c57f8a3a20540fcf9fbf98c0a73f381ec32fce2a. This
now also includes an extension of LLDB's workaround for handling special
members without the help of Sema to cover copy assignments.

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Revert "PR46209: properly determine whether a copy assignment operator is"

This reverts commit c57f8a3a20540fcf9fbf98c0a73f381ec32fce2a.

PR46209: properly determine whether a copy assignment operator is
trivial.

We previously took a shortcut by assuming that if a subobject had a
trivial copy assignment operator (with a few side-condi

PR46209: properly determine whether a copy assignment operator is
trivial.

We previously took a shortcut by assuming that if a subobject had a
trivial copy assignment operator (with a few side-conditions), we would
always invoke it, and could avoid going through overload resolution.
That turns out to not be correct in the presenve of ref-qualifiers (and
also won't be the case for copy-assignments with requires-clauses
either). Use the same logic for lazy declaration of copy-assignments
that we use for all other special member functions.

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[clangd] Add access specifier information to hover contents

Summary:
For https://github.com/clangd/clangd/issues/382

This commit adds access specifier information to the hover
contents. For example

[clangd] Add access specifier information to hover contents

Summary:
For https://github.com/clangd/clangd/issues/382

This commit adds access specifier information to the hover
contents. For example, the hover information of a class field or
member function will now indicate if the field or member is private,
public, or protected. This can be particularly useful when a developer
is in the implementation file and wants to know if a particular member
definition is public or private.

Reviewers: kadircet

Reviewed By: kadircet

Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D80472

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[NFC] Refactoring PropertyAttributeKind for ObjCPropertyDecl and ObjCDeclSpec.

This is a code clean up of the PropertyAttributeKind and
ObjCPropertyAttributeKind enums in ObjCPropertyDecl and ObjCDe

[NFC] Refactoring PropertyAttributeKind for ObjCPropertyDecl and ObjCDeclSpec.

This is a code clean up of the PropertyAttributeKind and
ObjCPropertyAttributeKind enums in ObjCPropertyDecl and ObjCDeclSpec that are
exactly identical. This non-functional change consolidates these enums
into one. The changes are to many files across clang (and comments in LLVM) so
that everything refers to the new consolidated enum in DeclObjCCommon.h.

2nd Landing Attempt...

Differential Revision: https://reviews.llvm.org/D77233

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