Commit Graph

1037 Commits

Author SHA1 Message Date
Erich Keane 3ff86f9610 [NFC] Start saving InstantiatedFromDecl in non-template functions
In cases where a non-template function is defined inside a function
template, we don't have information about the original uninstantiated
version.  In the case of concepts instantiation, we will need the
ability to get back to the original template.  This patch splits a piece
of the deferred concepts instantaition patch off to accomplish the
storage of this, with minor runtime overhead, and zero additional
storage.
2022-07-22 12:37:14 -07:00
Kazu Hirata cb2c8f694d [clang] Use value instead of getValue (NFC) 2022-07-13 23:39:33 -07:00
serge-sans-paille da6a14b91a [clang] Enforce instantiation of constexpr template functions during non-constexpr evaluation
Otherwise these functions are not instantiated and we end up with an undefined
symbol.

Fix #55560

Differential Revision: https://reviews.llvm.org/D128119
2022-07-10 08:40:03 +02:00
Erich Keane 258c3aee54 Revert "Re-apply "Deferred Concept Instantiation Implementation"""
This reverts commit befa8cf087.

Apparently this breaks some libc++ builds with an apparent assertion,
 so I'm looking into that .
2022-07-01 11:20:16 -07:00
Erich Keane befa8cf087 Re-apply "Deferred Concept Instantiation Implementation""
This reverts commit d4d47e574e.

This fixes the lldb crash that was observed by ensuring that our
friend-'template contains reference to' TreeTransform properly handles a
TemplateDecl.
2022-07-01 06:51:38 -07:00
Jonas Devlieghere d4d47e574e
Revert "Deferred Concept Instantiation Implementation"
This reverts commit 2f20743952 because it
triggers an assertion when building an LLDB test program:

  Assertion failed: (InstantiatingSpecializations.empty() && "failed to
  clean up an InstantiatingTemplate?"), function ~Sema, file
  /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/clang/lib/Sema/Sema.cpp,
  line 458.

More details in https://reviews.llvm.org/D126907.
2022-06-30 11:43:10 -07:00
Erich Keane 2f20743952 Deferred Concept Instantiation Implementation
This is a continuation of D119544.  Based on @rsmith 's feed back
showing me https://eel.is/c++draft/temp#friend-9, We should properly
handle friend functions now.

Differential Revision: https://reviews.llvm.org/D126907
2022-06-30 06:47:11 -07:00
Kazu Hirata 3b7c3a654c Revert "Don't use Optional::hasValue (NFC)"
This reverts commit aa8feeefd3.
2022-06-25 11:56:50 -07:00
Kazu Hirata aa8feeefd3 Don't use Optional::hasValue (NFC) 2022-06-25 11:55:57 -07:00
Kazu Hirata 06decd0b41 [clang] Use value_or instead of getValueOr (NFC) 2022-06-18 23:21:34 -07:00
Roy Jacobson 21eb1af469 [Concepts] Implement overload resolution for destructors (P0848)
This patch implements a necessary part of P0848, the overload resolution for destructors.
It is now possible to overload destructors based on constraints, and the eligible destructor
will be selected at the end of the class.

The approach this patch takes is to perform the overload resolution in Sema::ActOnFields
and to mark the selected destructor using a new property in FunctionDeclBitfields.

CXXRecordDecl::getDestructor is then modified to use this property to return the correct
destructor.

This closes https://github.com/llvm/llvm-project/issues/45614.

Reviewed By: #clang-language-wg, erichkeane

Differential Revision: https://reviews.llvm.org/D126194
2022-06-19 00:30:37 +03:00
Andrew Browne c7689fd552 [Clang] Fix memory leak due to TemplateArgumentListInfo used in AST node.
It looks like the leak is rooted at the allocation here:
1a155ee7de/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp (L3857)

The VarTemplateSpecializationDecl is allocated using placement new which uses the AST structure for ownership: 1a155ee7de/clang/lib/AST/DeclBase.cpp (L99)

The problem is the TemplateArgumentListInfo inside 1a155ee7de/clang/include/clang/AST/DeclTemplate.h (L2721)
This object contains a vector which does not use placement new: 1a155ee7de/clang/include/clang/AST/TemplateBase.h (L564)

Apparently ASTTemplateArgumentListInfo should be used instead 1a155ee7de/clang/include/clang/AST/TemplateBase.h (L575)

https://reviews.llvm.org/D125802#3551305

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D126944
2022-06-08 09:58:25 -07:00
Erich Keane 017abbb258 Revert ""Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation"""""
This reverts commit a425cac31e.

There is another libc++ test, that this time causes us to hit an
assertion. Reverting, likely for a while this time.
2022-05-09 09:12:05 -07:00
Erich Keane a425cac31e "Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation""""
This includes a fix for the libc++ issue I ran across with friend
declarations not properly being identified as overloads.

This reverts commit 45c07db31c.
2022-05-09 06:29:47 -07:00
Erich Keane 45c07db31c Revert "Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation"""
This reverts commit a97899108e.

The patch caused some problems with the libc++ `__range_adaptor_closure`
that I haven't been able to figure out the cause of, so I am reverting
while I figure out whether this is a solvable problem/issue with the
  CFE, or libc++ depending on an older 'incorrect' behavior.
2022-05-02 11:12:14 -07:00
Erich Keane a97899108e Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation""
This reverts commit 0c31da4838.

I've solved the issue with the PointerUnion by making the
`FunctionTemplateDecl` pointer be a NamedDecl, that could be a
`FunctionDecl` or `FunctionTemplateDecl` depending.  This is enforced
with an assert.
2022-05-02 07:49:26 -07:00
Erich Keane 0c31da4838 Revert "Deferred Concept Instantiation Implementation"
This reverts commit 4b6c2cd647.

The patch caused numerous ARM 32 bit build failures, since we added a
5th item to the PointerUnion, and went over the 2-bits available in the
32 bit pointers.
2022-05-02 06:25:38 -07:00
Erich Keane 4b6c2cd647 Deferred Concept Instantiation Implementation
As reported here: https://github.com/llvm/llvm-project/issues/44178

Concepts are not supposed to be instantiated until they are checked, so
this patch implements that and goes through significant amounts of work
to make sure we properly re-instantiate the concepts correctly.

Differential Revision: https://reviews.llvm.org/D119544
2022-05-02 05:49:15 -07:00
Richard Smith 72315d02c4 Treat `std::move`, `forward`, etc. as builtins.
This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.

We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.

This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.

We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.

In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.

The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.

This is a re-commit of
  fc30901096,
  a571f82a50,
  64c045e25b, and
  de6ddaeef3,
and reverts aa643f455a.
This change also includes a workaround for users using libc++ 3.1 and
earlier (!!), as apparently happens on AIX, where std::move sometimes
returns by value.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123345

Revert "Fixup D123950 to address revert of D123345"

This reverts commit aa643f455a.
2022-04-20 17:58:31 -07:00
David Tenty 98d911e01f Revert "Treat `std::move`, `forward`, etc. as builtins."
This reverts commit b27430f9f4 as the
    parent https://reviews.llvm.org/D123345 breaks the AIX CI:

    https://lab.llvm.org/buildbot/#/builders/214/builds/819
2022-04-20 19:14:37 -04:00
David Tenty de6ddaeef3 Revert "Don't treat 'T &forward(T&&)' as builtin."
This reverts commit e43c93dd63 as the
parent https://reviews.llvm.org/D123345 breaks the AIX CI.
2022-04-20 19:14:36 -04:00
Richard Smith e43c93dd63 Don't treat 'T &forward(T&&)' as builtin.
This allows the standard library to diagnose it properly. Suppress
warning in libc++ testsuite for unused result of call to std::forward.
2022-04-18 11:11:21 -07:00
Richard Smith b27430f9f4 Treat `std::move`, `forward`, etc. as builtins.
This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.

We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.

This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.

We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.

In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.

The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.

This is a re-commit of
  fc30901096,
  a571f82a50, and
  64c045e25b
which were reverted in
  e75d8b7037
due to a crasher bug where CodeGen would emit a builtin glvalue as an
rvalue if it constant-folds.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123345
2022-04-17 13:26:16 -07:00
Vitaly Buka e75d8b7037 Revert "Treat `std::move`, `forward`, and `move_if_noexcept` as builtins."
Revert "Extend support for std::move etc to also cover std::as_const and"
Revert "Update test to handle opaque pointers flag flip."

It crashes on libcxx tests https://lab.llvm.org/buildbot/#/builders/85/builds/8174

This reverts commit fc30901096.
This reverts commit a571f82a50.
This reverts commit 64c045e25b.
2022-04-16 00:27:51 -07:00
Richard Smith 64c045e25b Treat `std::move`, `forward`, and `move_if_noexcept` as builtins.
We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.

This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.

We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.

In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.

The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123345
2022-04-15 14:09:45 -07:00
Aaron Ballman 385e7df330 Correctly diagnose prototype redeclaration errors in C
We did not implement C99 6.7.5.3p15 fully in that we missed the rule
for compatible function types where a prior declaration has a prototype
and a subsequent definition (not just declaration) has an empty
identifier list or an identifier list with a mismatch in parameter
arity. This addresses that situation by issuing an error on code like:

void f(int);
void f() {} // type conflicts with previous declaration

(Note: we already diagnose the other type conflict situations
appropriately, this was the only situation we hadn't covered that I
could find.)
2022-04-13 08:21:31 -04:00
Hans Wennborg 40ad667013 [dllexport] odr-use constexpr default args for constructor closures
InstantiateDefaultCtorDefaultArgs() is supposed to mark default
constructor args as odr-used, since those args will be used when
emitting the constructor closure.

However, constexpr vars were not getting odr-used since
DoMarkVarDeclReferenced() defers them in MaybeODRUseExprs, and the code
was calling CleanupVarDeclMarking() which discarded those uses instead
of processing them.

(This came up in Chromium, crbug.com/1312086)

Differential revision: https://reviews.llvm.org/D123405
2022-04-11 16:23:01 +02:00
James Y Knight d614874900 [Clang] Implement __builtin_source_location.
This builtin returns the address of a global instance of the
`std::source_location::__impl` type, which must be defined (with an
appropriate shape) before calling the builtin.

It will be used to implement std::source_location in libc++ in a
future change. The builtin is compatible with GCC's implementation,
and libstdc++'s usage. An intentional divergence is that GCC declares
the builtin's return type to be `const void*` (for
ease-of-implementation reasons), while Clang uses the actual type,
`const std::source_location::__impl*`.

In order to support this new functionality, I've also added a new
'UnnamedGlobalConstantDecl'. This artificial Decl is modeled after
MSGuidDecl, and is used to represent a generic concept of an lvalue
constant with global scope, deduplicated by its value. It's possible
that MSGuidDecl itself, or some of the other similar sorts of things
in Clang might be able to be refactored onto this more-generic
concept, but there's enough special-case weirdness in MSGuidDecl that
I gave up attempting to share code there, at least for now.

Finally, for compatibility with libstdc++'s <source_location> header,
I've added a second exception to the "cannot cast from void* to T* in
constant evaluation" rule. This seems a bit distasteful, but feels
like the best available option.

Reviewers: aaron.ballman, erichkeane

Differential Revision: https://reviews.llvm.org/D120159
2022-03-28 18:29:02 -04:00
Corentin Jabot 3784e8ccfb [Clang] Fix Unevaluated Lambdas
Unlike other types, when lambdas are instanciated,
they are recreated from scratch.
When an unevaluated lambdas appear in the type of a function,
parameter it is instanciated in the wrong declaration context,
as parameters are transformed before the function.

To support lambda in function parameters, we try to
compute whether they are dependant without looking at the
declaration context.

This is a short term stopgap solution to avoid clang
iceing. A better fix might be to inject some kind of
transparent declaration with correctly computed dependency
for function parameters, variable templates, etc.

Fixes https://github.com/llvm/llvm-project/issues/50376
Fixes https://github.com/llvm/llvm-project/issues/51414
Fixes https://github.com/llvm/llvm-project/issues/51416
Fixes https://github.com/llvm/llvm-project/issues/51641
Fixes https://github.com/llvm/llvm-project/issues/54296

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D121532
2022-03-25 19:16:45 +01:00
Kristina Bessonova afbe54f2fe [clang] Fix wrong -Wunused-local-typedef warning within a template function
Partially fixes PR24883.

The patch sets Reference bit while instantiating a typedef if it
previously was found referenced.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D114382
2022-03-21 13:21:25 +02:00
Benjamin Kramer 5d2ce7663b Use llvm::append_range instead of push_back loops where applicable. NFCI. 2022-03-18 01:25:34 +01:00
Erich Keane 94623fb1c9 [NFC] move CheckInstantiatedFunctionTemplateConstraints to SemaConcepts.cpp
This is a Sema function that now no longer depends on any of the
functionality in SemaTemplateInstantiateDecl.cpp (as the static function
was moved to Sema in a previous NFC).  Moving it to SemaConcept means
that it and CheckFunctionConstraints can be changed to share more.
2022-03-03 11:47:20 -08:00
Erich Keane c601377b23 [NFC]Promote addInstantiatedParametersToScope to a private Sema function
This is used a few places in SemaTeplateInstantiateDecl, but is going
to be useful in SemaConcept.cpp as well. This patch switches it to be
a private function in Sema.

Differential Revision: https://reviews.llvm.org/D120729
2022-03-01 08:31:51 -08:00
David Stone 0bff3a9650 Lambdas are not necessarily locals. This resolves DR48250.
Differential Revision: https://reviews.llvm.org/D99134
2022-02-18 06:11:28 -08:00
Steffen Larsen ead1690d31 Allow parameter pack expansions and initializer lists in annotate attribute
These changes make the Clang parser recognize expression parameter pack
expansion and initializer lists in attribute arguments. Because
expression parameter pack expansion requires additional handling while
creating and instantiating templates, the support for them must be
explicitly supported through the AcceptsExprPack flag.

Handling expression pack expansions may require a delay to when the
arguments of an attribute are correctly populated. To this end,
attributes that are set to accept these - through setting the
AcceptsExprPack flag - will automatically have an additional variadic
expression argument member named DelayedArgs. This member is not
exposed the same way other arguments are but is set through the new
CreateWithDelayedArgs creator function generated for applicable
attributes.

To illustrate how to implement support for expression pack expansion
support, clang::annotate is made to support pack expansions. This is
done by making handleAnnotationAttr delay setting the actual attribute
arguments until after template instantiation if it was unable to
populate the arguments due to dependencies in the parsed expressions.
2022-02-08 13:38:07 -05:00
Kazu Hirata 17d4bd3d78 [clang] Fix bugprone argument comments (NFC)
Identified with bugprone-argument-comment.
2022-01-09 00:19:49 -08:00
David Pagan b0de656bdf Initial parsing/sema for 'align' clause
Added basic parsing/sema/serialization support for 'align' clause for use with
'allocate' directive.
2021-11-09 07:34:18 -05:00
Sam McCall 6a5e08cc4a [AST] injected-class-name is not a redecl, even in template specializations
Back in the mists of time, the CXXRecordDecl for the injected-class-name was
a redecl of the outer class itself.
This got changed in 470c454a61, but only for plain
classes: class template instantation was still detecting the injected-class-name
in the template body and marking its instantiation as a redecl.

This causes some subtle inconsistent behavior between the two, e.g.
hasDefinition() returns true for Foo<int>::Foo but false for Bar::Bar.
This is the root cause of PR51912.

Differential Revision: https://reviews.llvm.org/D112765
2021-11-02 14:37:45 +01:00
Mike Rice d8699391a4 [OPENMP51]Initial parsing/sema for append_args clause for 'declare variant'
Adds initial parsing and sema for the 'append_args' clause.

Note that an AST clause is not created as it instead adds its values
to the OMPDeclareVariantAttr.

Differential Revision: https://reviews.llvm.org/D111854
2021-10-25 09:38:50 -07:00
Simon Pilgrim b577126d62 [clang][sema] instantiateOMPDeclareVariantAttr - merge repeated VariantFuncRef.get() calls. NFCI.
Fixes scan-build warning about dead initialization
2021-10-14 12:51:34 +01:00
Mike Rice fb4c451001 [OPENMP51]Initial parsing/sema for adjust_args clause for 'declare variant'
Adds initial parsing and sema for the 'adjust_args' clause.

Note that an AST clause is not created as it instead adds its expressions
to the OMPDeclareVariantAttr.

Differential Revision: https://reviews.llvm.org/D99905
2021-10-13 09:34:09 -07:00
Matheus Izvekov 1f6458cb19
[clang] NFC: remove duplicated code around type constraint and templ arg subst
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D110726
2021-09-29 23:05:46 +02:00
Erich Keane 9324cc2ca9 Change __builtin_sycl_unique_stable_name to just use an Itanium mangling
After significant problems in our downstream with the previous
implementation, the SYCL standard has opted to make using macros/etc to
change kernel-naming-lambdas in any way UB (even passively). As a
result, we are able to just emit the itanium mangling.

However, this DOES require a little work in the CXXABI, as the microsoft
and itanium mangler use different numbering schemes for lambdas.  This
patch adds a pair of mangling contexts that use the normal 'itanium'
mangling strategy to fill in the "DeviceManglingNumber" used previously
by CUDA.

Differential Revision: https://reviews.llvm.org/D110281
2021-09-28 06:41:03 -07:00
Nico Weber bde305baf6 [clang] Fix a few comment more typos to cycle bots 2021-09-20 19:42:49 -04:00
Matheus Izvekov d98c34f4d7 [clang] fix error recovery ICE on copy elision when returing invalid variable
See PR51708.

Attempting copy elision in dependent contexts with invalid variable,
such as a variable with incomplete type, would cause a crash when attempting
to calculate it's alignment.

The fix is to just skip this optimization on invalid VarDecl, as otherwise this
provides no benefit to error recovery: This functionality does not try to
diagnose anything, it only calculates a flag which will affect where the
variable will be allocated during codegen.

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Reviewed By: rtrieu

Differential Revision: https://reviews.llvm.org/D109191
2021-09-03 20:34:08 +02:00
Melanie Blower bc5b5ea037 [clang][patch][FPEnv] Make initialization of C++ globals strictfp aware
@kpn pointed out that the global variable initialization functions didn't
have the "strictfp" metadata set correctly, and @rjmccall said that there
was buggy code in SetFPModel and StartFunction, this patch is to solve
those problems. When Sema creates a FunctionDecl, it sets the
FunctionDeclBits.UsesFPIntrin to "true" if the lexical FP settings
(i.e. a combination of command line options and #pragma float_control
settings) correspond to ConstrainedFP mode. That bit is used when CodeGen
starts codegen for a llvm function, and it translates into the
"strictfp" function attribute. See bugs.llvm.org/show_bug.cgi?id=44571

Reviewed By: Aaron Ballman

Differential Revision: https://reviews.llvm.org/D102343
2021-07-29 12:02:37 -04:00
Bruno Cardoso Lopes c9aaf34b8d [SemaCXX] Handle lack of TypeSourceInfo on special member functions in templated lambdas
During template instantiation involving templated lambdas, clang
could hit an assertion in `TemplateDeclInstantiator::SubstFunctionType`
since the functions are not associated with any `TypeSourceInfo`:

`assert(OldTInfo && "substituting function without type source info");`

This path is triggered when using templated lambdas like the one added as
a test to this patch. To fix this:

- Create `TypeSourceInfo`s for special members and make sure the template
instantiator can get through all patterns.
- Introduce a `SpecialMemberTypeInfoRebuilder` tree transform to rewrite
such member function arguments. Without this, we get errors like:

`error: only special member functions and comparison operators may be defaulted`

since `getDefaultedFunctionKind` can't properly recognize these functions
as special members as part of `SetDeclDefaulted`.

Fixes PR45828 and PR44848

Differential Revision: https://reviews.llvm.org/D88327
2021-06-22 17:26:05 -07:00
Matheus Izvekov 12c90e2e25 [clang] NRVO: Improvements and handling of more cases.
This expands NRVO propagation for more cases:

Parse analysis improvement:
* Lambdas and Blocks with dependent return type can have their variables
  marked as NRVO Candidates.

Variable instantiation improvements:
* Fixes crash when instantiating NRVO variables in Blocks.
* Functions, Lambdas, and Blocks which have auto return type have their
  variables' NRVO status propagated. For Blocks with non-auto return type,
  as a limitation, this propagation does not consider the actual return
  type.

This also implements exclusion of VarDecls which are references to
dependent types.

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Reviewed By: Quuxplusone

Differential Revision: https://reviews.llvm.org/D99696
2021-06-17 01:56:38 +02:00
Yaxun (Sam) Liu 79f9cfbc21 Do not merge LocalInstantiationScope for template specialization
A lambda in a function template may be recursively instantiated. The recursive
lambda will cause a lambda function instantiated multiple times, one inside another.
The inner LocalInstantiationScope should not be marked as MergeWithParentScope
since it already has references to locals properly substituted, otherwise it causes
assertion due to the check for duplicate locals in merged LocalInstantiationScope.

Reviewed by: Richard Smith

Differential Revision: https://reviews.llvm.org/D98068
2021-06-14 23:28:04 -04:00
Hans Wennborg c60dd3b262 Revert "[clang] NRVO: Improvements and handling of more cases."
This change caused build errors related to move-only __block variables,
see discussion on https://reviews.llvm.org/D99696

> This expands NRVO propagation for more cases:
>
> Parse analysis improvement:
> * Lambdas and Blocks with dependent return type can have their variables
>   marked as NRVO Candidates.
>
> Variable instantiation improvements:
> * Fixes crash when instantiating NRVO variables in Blocks.
> * Functions, Lambdas, and Blocks which have auto return type have their
>   variables' NRVO status propagated. For Blocks with non-auto return type,
>   as a limitation, this propagation does not consider the actual return
>   type.
>
> This also implements exclusion of VarDecls which are references to
> dependent types.
>
> Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
>
> Reviewed By: Quuxplusone
>
> Differential Revision: https://reviews.llvm.org/D99696

This also reverts the follow-on change which was hard to tease apart
form the one above:

> "[clang] Implement P2266 Simpler implicit move"
>
> This Implements [[http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2266r1.html|P2266 Simpler implicit move]].
>
> Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
>
> Reviewed By: Quuxplusone
>
> Differential Revision: https://reviews.llvm.org/D99005

This reverts commits 1e50c3d785 and
bf20631782.
2021-06-14 16:46:58 +02:00