Commit Graph

1710 Commits

Author SHA1 Message Date
Kazu Hirata 17d4bd3d78 [clang] Fix bugprone argument comments (NFC)
Identified with bugprone-argument-comment.
2022-01-09 00:19:49 -08:00
Simon Pilgrim e3e8799beb [AST] ASTContext::mergeTypes - pull out repeated getAs<> calls. NFC.
Avoids static-analyzer null dereference warnings.
2022-01-06 16:04:36 +00:00
Kazu Hirata 298367ee6e [clang] Use nullptr instead of 0 or NULL (NFC)
Identified with modernize-use-nullptr.
2021-12-29 08:34:20 -08:00
Kazu Hirata 76f0f1cc5c Use {DenseSet,SetVector,SmallPtrSet}::contains (NFC) 2021-12-24 21:43:06 -08:00
Sam McCall af27466c50 Reland "[AST] Add UsingType: a sugar type for types found via UsingDecl"
This reverts commit cc56c66f27.
Fixed a bad assertion, the target of a UsingShadowDecl must not have
*local* qualifiers, but it can be a typedef whose underlying type is qualified.
2021-12-20 18:03:15 +01:00
Sam McCall cc56c66f27 Revert "[AST] Add UsingType: a sugar type for types found via UsingDecl"
This reverts commit e1600db19d.

Breaks sanitizer tests, at least on windows:
https://lab.llvm.org/buildbot/#/builders/127/builds/21592/steps/4/logs/stdio
2021-12-20 17:53:56 +01:00
Sam McCall e1600db19d [AST] Add UsingType: a sugar type for types found via UsingDecl
Currently there's no way to find the UsingDecl that a typeloc found its
underlying type through. Compare to DeclRefExpr::getFoundDecl().

Design decisions:
- a sugar type, as there are many contexts this type of use may appear in
- UsingType is a leaf like TypedefType, the underlying type has no TypeLoc
- not unified with UnresolvedUsingType: a single name is appealing,
  but being sometimes-sugar is often fiddly.
- not unified with TypedefType: the UsingShadowDecl is not a TypedefNameDecl or
  even a TypeDecl, and users think of these differently.
- does not cover other rarer aliases like objc @compatibility_alias,
  in order to be have a concrete API that's easy to understand.
- implicitly desugared by the hasDeclaration ASTMatcher, to avoid
  breaking existing patterns and following the precedent of ElaboratedType.

Scope:
- This does not cover types associated with template names introduced by
  using declarations. A future patch should introduce a sugar TemplateName
  variant for this. (CTAD deduced types fall under this)
- There are enough AST matchers to fix the in-tree clang-tidy tests and
  probably any other matchers, though more may be useful later.

Caveats:
- This changes a fairly common pattern in the AST people may depend on matching.
  Previously, typeLoc(loc(recordType())) matched whether a struct was
  referred to by its original scope or introduced via using-decl.
  Now, the using-decl case is not matched, and needs a separate matcher.
  This is similar to the case of typedefs but nevertheless both adds
  complexity and breaks existing code.

Differential Revision: https://reviews.llvm.org/D114251
2021-12-20 17:15:38 +01:00
Chuanqi Xu c50a4b3f97 [Modules] Incorrect ODR detection for unresolved using type
Implement `getUnresolvedUsingType()` and don't create a new
`UnresolvedUsingType` when there is already canonical declaration.

This solved an incorrect ODR detection in modules for uresolved using
type.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D115792
2021-12-17 10:37:40 +08:00
Aaron Ballman 6c75ab5f66 Introduce _BitInt, deprecate _ExtInt
WG14 adopted the _ExtInt feature from Clang for C23, but renamed the
type to be _BitInt. This patch does the vast majority of the work to
rename _ExtInt to _BitInt, which accounts for most of its size. The new
type is exposed in older C modes and all C++ modes as a conforming
extension. However, there are functional changes worth calling out:

* Deprecates _ExtInt with a fix-it to help users migrate to _BitInt.
* Updates the mangling for the type.
* Updates the documentation and adds a release note to warn users what
is going on.
* Adds new diagnostics for use of _BitInt to call out when it's used as
a Clang extension or as a pre-C23 compatibility concern.
* Adds new tests for the new diagnostic behaviors.

I want to call out the ABI break specifically. We do not believe that
this break will cause a significant imposition for early adopters of
the feature, and so this is being done as a full break. If it turns out
there are critical uses where recompilation is not an option for some
reason, we can consider using ABI tags to ease the transition.
2021-12-06 12:52:01 -05:00
Erich Keane fc53eb69c2 Reapply 'Implement target_clones multiversioning'
See discussion in D51650, this change was a little aggressive in an
error while doing a 'while we were here', so this removes that error
condition, as it is apparently useful.

This reverts commit bb4934601d.
2021-11-29 06:30:01 -08:00
Wei Wang a075d67222 [Sema] fix nondeterminism in ASTContext::getDeducedTemplateSpecializationType
`DeducedTemplateSpecializationTypes` is a `llvm::FoldingSet<DeducedTemplateSpecializationType>` [1],
where `FoldingSetNodeID` is based on the values: {`TemplateName`, `QualType`, `IsDeducedAsDependent`},
those values are also used as `DeducedTemplateSpecializationType` constructor arguments.

A `FoldingSetNodeID` created by the static `DeducedTemplateSpecializationType::Profile` may not be equal
to`FoldingSetNodeID` created by a member `DeducedTemplateSpecializationType::Profile` of an instance
created with the same {`TemplateName`, `QualType`, `IsDeducedAsDependent`}, which makes
`DeducedTemplateSpecializationTypes` lookups nondeterministic.

Specifically, while `IsDeducedAsDependent` value is passes to the constructor, `IsDependent()` method on
the created instance may return a different value, because `IsDependent` is not saved as is:
```name=clang/include/clang/AST/Type.h
  DeducedTemplateSpecializationType(TemplateName Template,  QualType DeducedAsType, bool IsDeducedAsDependent)
      : DeducedType(DeducedTemplateSpecialization, DeducedAsType,
                    toTypeDependence(Template.getDependence()) | // <~  also considers `TemplateName` parameter
                        (IsDeducedAsDependent ? TypeDependence::DependentInstantiation : TypeDependence::None)),
```
For example, if an instance A with key `FoldingSetNodeID {A, B, false}` is inserted. Then a key
`FoldingSetNodeID {A, B, true}` is probed:
If it happens to correspond to the same bucket in `FoldingSet` as the first key, and `A.Profile()` returns
`FoldingSetNodeID {A, B, true}`, then it's a hit.
If the bucket for the second key is different from the first key, instance A is not considered at all, and it's
a no hit, even if `A.Profile()` returns  `FoldingSetNodeID {A, B, true}`.

Since `TemplateName`, `QualType` parameter values involve memory pointers, the lookup result depend on allocator,
and may differ from run to run. When this is used as part of modules compilation, it may result in "module out of date"
errors, if imported modules are built on different machines.

This makes `ASTContext::getDeducedTemplateSpecializationType` consider `Template.isDependent()` similar
`DeducedTemplateSpecializationType` constructor.

Tested on a very big codebase, by running modules compilations from directories with varied path length
(seem to affect allocator seed).

1. https://llvm.org/docs/ProgrammersManual.html#llvm-adt-foldingset-h

Patch by Wei Wang and Igor Sugak!

Reviewed By: bruno

Differential Revision: https://reviews.llvm.org/D112481
2021-11-19 13:22:07 -08:00
Matheus Izvekov c9e46219f3
[clang] retain type sugar in auto / template argument deduction
This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses the sugared type all the way
down. It would previously lose the sugar on first recursion.
* Undeduced AutoType will be properly canonicalized, including the constraint
template arguments.
* Remove the decltype node created from the decltype(auto) deduction.

As a result, we start seeing sugared types in a lot more test cases,
including some which showed very unfriendly `type-parameter-*-*` types.

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

Reviewed By: rsmith, #libc, ldionne

Differential Revision: https://reviews.llvm.org/D110216
2021-11-15 23:07:45 +01:00
Matheus Izvekov 6438a52df1
Revert "[clang] retain type sugar in auto / template argument deduction"
This reverts commit 4d8fff477e.
2021-11-15 00:29:05 +01:00
Matheus Izvekov 4d8fff477e
[clang] retain type sugar in auto / template argument deduction
This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses the sugared type all the way
down. It would previously lose the sugar on first recursion.
* Undeduced AutoType will be properly canonicalized, including the constraint
template arguments.
* Remove the decltype node created from the decltype(auto) deduction.

As a result, we start seeing sugared types in a lot more test cases,
including some which showed very unfriendly `type-parameter-*-*` types.

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

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D110216
2021-11-13 03:35:22 +01:00
Adrian Kuegel 1d7fdbbc18 Revert "[clang] retain type sugar in auto / template argument deduction"
This reverts commit 9b6036deed.
Breaks two libc++ tests.
2021-11-12 13:21:59 +01:00
Adrian Kuegel bb4934601d Revert "Implement target_clones multiversioning"
This reverts commit 9deab60ae7.
There is a possibly unintended semantic change.
2021-11-12 11:05:58 +01:00
Matheus Izvekov 9b6036deed
[clang] retain type sugar in auto / template argument deduction
This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses the sugared type all the way
down. It would previously lose the sugar on first recursion.
* Undeduced AutoType will be properly canonicalized, including the constraint
template arguments.
* Remove the decltype node created from the decltype(auto) deduction.

As a result, we start seeing sugared types in a lot more test cases,
including some which showed very unfriendly `type-parameter-*-*` types.

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

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D110216
2021-11-12 01:16:31 +01:00
Erich Keane 9deab60ae7 Implement target_clones multiversioning
As discussed here: https://lwn.net/Articles/691932/

GCC6.0 adds target_clones multiversioning. This functionality is
an odd cross between the cpu_dispatch and 'target' MV, but is compatible
with neither.

This attribute allows you to list all options, then emits a separately
optimized version of each function per-option (similar to the
cpu_specific attribute). It automatically generates a resolver, just
like the other two.

The mangling however, is... ODD to say the least. The mangling format
is:
<normal_mangling>.<option string>.<option ordinal>.

Differential Revision:https://reviews.llvm.org/D51650
2021-11-11 11:11:16 -08:00
Craig Topper 893efd0d66 [X86] Honor command line features along with cpu_specific attribute
If the feature is on the command line we should honor it for all
functions. I don't think we could reliably target a single function
for a less capable processor than what the rest of the program is
compiled for.

Fixes PR52407.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D113647
2021-11-11 09:06:22 -08:00
Kazu Hirata 16ceb44e62 [clang] Use llvm::{count,count_if,find_if,all_of,none_of} (NFC) 2021-10-25 09:14:45 -07:00
Bradley Smith 0ce46a1d43 [AArch64][Driver][SVE] Allow -msve-vector-bits=<n>+ syntax to mean no maximum vscale
This patch splits the existing SveVectorBits LangOpt into VScaleMin and
VScaleMax LangOpts such that we can represent such an option. The cc1
option has also been split into -mvscale-{min,max}=<n> options so that the
cc1 arguments better reflect the vscale_range IR attribute.

Differential Revision: https://reviews.llvm.org/D111790
2021-10-25 11:10:52 +00:00
Kazu Hirata d245f2e859 [clang] Use llvm::erase_if (NFC) 2021-10-17 13:50:29 -07:00
Kazu Hirata 10726992fa Use llvm::erase_value (NFC) 2021-10-16 23:31:21 -07:00
Arthur Eubanks d0a5f61c4f [clang] Support -clear-ast-before-backend without -disable-free
Previously without -disable-free, -clear-ast-before-backend would crash in ~ASTContext() due to various reasons.
This works around that by doing a lot of the cleanup ahead of the destructor so that the destructor doesn't actually do any manual cleanup if we've already cleaned up beforehand.

This actually does save a measurable amount of memory with -clear-ast-before-backend, although at an almost unnoticeable runtime cost:
https://llvm-compile-time-tracker.com/compare.php?from=5d755b32f2775b9219f6d6e2feda5e1417dc993b&to=58ef1c7ad7e2ad45f9c97597905a8cf05a26258c&stat=max-rss

Previously we weren't doing any cleanup with -disable-free, so I tried measuring the impact of always doing the cleanup and didn't measure anything noticeable on llvm-compile-time-tracker.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D111767
2021-10-14 13:43:53 -07:00
Nathan Sidwell 444ec0957c [clang] p0388 array list initialization overloads
This is the second part of p0388, dealing with overloads of list
initialization to incomplete array types.  It extends the handling
added in D103088 to permit incomplete arrays.  We have to record that
the conversion involved an incomplete array, and so (re-add) a bit flag
into the standard conversion sequence object.  Comparing such
conversion sequences requires knowing (a) the number of array elements
initialized and (b) whether the initialization is of an incomplete array.

This also updates the web page to indicate p0388 is implemented (there
is no feature macro).

Differential Revision: https://reviews.llvm.org/D103908
2021-10-12 07:35:21 -07:00
Nathan Sidwell dcd74716f9 [clang] p0388 conversion to incomplete array
This implements the new implicit conversion sequence to an incomplete
(unbounded) array type.  It is mostly Richard Smith's work, updated to
trunk, testcases added and a few bugs fixed found in such testing.

It is not a complete implementation of p0388.

Differential Revision: https://reviews.llvm.org/D102645
2021-10-12 07:35:20 -07:00
Qiu Chaofan 85e565898f [Clang] Enable _Complex __ibm128 type
fae0dfa implemented the new __ibm128 type, this patch enables its
complex form.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D109948
2021-10-09 10:48:44 +08:00
Qiu Chaofan 8a714722e2 [NFC] [Clang] Use global enum for explicit float mode
Currently, there're multiple float types that can be represented by
__attribute__((mode(xx))). It's parsed, and then a corresponding type is
created if available.

This refactor moves the enum for mode into a global enum class visible
to ASTContext.

Reviewed By: aaron.ballman, erichkeane

Differential Revision: https://reviews.llvm.org/D111391
2021-10-09 10:39:10 +08:00
Qiu Chaofan 00c0ce0655 [NFC] [Clang] Remove pre-computed complex float types
As discussed in D109948, pre-computing all complex float types is not
necessary and brings extra overhead. This patch removes these defined
types, and construct them in-place when needed.

Reviewed By: teemperor

Differential Revision: https://reviews.llvm.org/D111387
2021-10-08 15:52:16 +08:00
Kamau Bridgeman 8737c74fab [PowerPC][MMA] Allow MMA builtin types in pre-P10 compilation units
This patch allows the use of __vector_quad and __vector_pair, PPC MMA builtin
types, on all PowerPC 64-bit compilation units. When these types are
made available the builtins that use them automatically become available
so semantic checking for mma and pair vector memop __builtins is also
expanded to ensure these builtin function call are only allowed on
Power10 and new architectures. All related test cases are updated to
ensure test coverage.

Reviewed By: #powerpc, nemanjai

Differential Revision: https://reviews.llvm.org/D109599
2021-10-05 07:59:32 -05:00
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 60ab6861ed [clang] Fix a few more comment typos to cycle bots 2021-09-20 20:06:03 -04:00
Steven Wan 806ff3c4a4 [AIX] Check for typedef properly when getting preferred type align
The current check for typedef is naive and doesn't deal with any convoluted cases. This patch makes use of the new 'AlignRequirement' enum field from 'TypeInfo' to determine whether or not this is an 'aligned' attribute on a typedef.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D109387
2021-09-08 16:21:52 -04:00
Qiu Chaofan fae0dfa642 [Clang] Add __ibm128 type to represent ppc_fp128
Currently, we have no front-end type for ppc_fp128 type in IR. PowerPC
target generates ppc_fp128 type from long double now, but there's option
(-mabi=(ieee|ibm)longdouble) to control it and we're going to do
transition from IBM extended double-double ppc_fp128 to IEEE fp128 in
the future.

This patch adds type __ibm128 which always represents ppc_fp128 in IR,
as what GCC did for that type. Without this type in Clang, compilation
will fail if compiling against future version of libstdcxx (which uses
__ibm128 in headers).

Although all operations in backend for __ibm128 is done by software,
only PowerPC enables support for it.

There's something not implemented in this commit, which can be done in
future ones:

- Literal suffix for __ibm128 type. w/W is suitable as GCC documented.
- __attribute__((mode(IF))) should be for __ibm128.
- Complex __ibm128 type.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D93377
2021-09-06 18:00:58 +08:00
Steven Wan 73733ae526 TypeInfo records more information about align requirement
Extend the information preserved in `TypeInfo` by replacing the `AlignIsRequired` bool flag with a three-valued enum, the enum also indicates where the alignment attribute come from, which could be helpful in determining whether the attribute should overrule.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D108858
2021-08-28 19:47:48 -04:00
Johannes Doerfert 2930c839a5 [OpenMP][FIX] Allow declare variant to work with reference types
Reference types in the return or parameter position did cause the OpenMP
declare variant overload reasoning to give up. We should allow them as
we allow any other type.

This should fix the bug reported on the mailing list:
https://lists.llvm.org/pipermail/openmp-dev/2021-August/004094.html

Reviewed By: ABataev, pdhaliwal

Differential Revision: https://reviews.llvm.org/D108774
2021-08-27 13:12:14 -05:00
Gabor Bencze ad59735f9d Fix __has_unique_object_representations with no_unique_address
Fix incorrect behavior of `__has_unique_object_representations`
when using the no_unique_address attribute.
Based on the bug report: https://bugs.llvm.org/show_bug.cgi?id=47722

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D89649
2021-08-26 09:23:37 +02:00
Simon Pilgrim 5b72fb866c [AST] getDeclLocForCommentSearch - remove dead return. NFC.
Don't use an else-block as the previous if-block always returns, and remove the (now more obvious) dead return {}.
2021-08-20 12:32:29 +01:00
Steven Wan a91916500d [AIX] "aligned" attribute should not decrease type alignment returned by __alignof__
`__alignof__(x)` always returns `ABIAlign` if the "x" is marked `__attribute__((aligned()))`. However, the "aligned" attribute should only increase the alignment of a struct, or struct member, unless it's used together with the "packed" attribute, or used as a part of a typedef, in which case, the "aligned" attribute can both increase and decrease alignment.

Reviewed By: sfertile

Differential Revision: https://reviews.llvm.org/D107598
2021-08-05 18:18:58 -04:00
Matheus Izvekov 219790c1f5 [clang] fix canonicalization of nested name specifiers
See PR47174.

When canonicalizing nested name specifiers of the type kind,
the prefix for 'DependentTemplateSpecialization' types was being
dropped, leading to malformed types which would cause failures
when rebuilding template names.

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

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D107311
2021-08-03 22:39:48 +02:00
Matheus Izvekov 0c7cd4a873 [clang] NFC: refactor multiple implementations of getDecltypeForParenthesizedExpr
This cleanup patch refactors a bunch of functional duplicates of
getDecltypeForParenthesizedExpr into a common implementation.

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

Reviewed By: aaronpuchert

Differential Revision: https://reviews.llvm.org/D100713
2021-07-28 23:27:43 +02:00
Jun Ma 599b2f0037 [AArch64][SVE] Handle svbool_t VLST <-> VLAT/GNUT conversion
According to https://godbolt.org/z/q5rME1naY and acle, we found that
there are different SVE conversion behaviours between clang and gcc. It turns
out that llvm does not handle SVE predicates width properly.

This patch 1) checks SVE predicates width rightly with svbool_t type.
2) removes warning on svbool_t VLST <-> VLAT/GNUT conversion.
3) disables VLST <-> VLAT/GNUT conversion between SVE vectors and predicates
due to different width.

Differential Revision: https://reviews.llvm.org/D106333
2021-07-22 13:55:08 +08:00
Hsiangkai Wang 77bb82d068 [Clang][RISCV] Support half-precision floating point for RVV intrinsics.
Use _Float16 as the half-precision floating point type. Define a new
type specifier 'x' for the _Float16 type.

Differential Revision: https://reviews.llvm.org/D105001
2021-07-19 23:17:01 +08:00
Vassil Vassilev 11b47c103a Reland "[clang-repl] Implement partial translation units and error recovery."
Original commit message:

[clang-repl] Implement partial translation units and error recovery.

https://reviews.llvm.org/D96033 contained a discussion regarding efficient
modeling of error recovery. @rjmccall has outlined the key ideas:

Conceptually, we can split the translation unit into a sequence of partial
translation units (PTUs). Every declaration will be associated with a unique PTU
that owns it.

The first key insight here is that the owning PTU isn't always the "active"
(most recent) PTU, and it isn't always the PTU that the declaration
"comes from". A new declaration (that isn't a redeclaration or specialization of
anything) does belong to the active PTU. A template specialization, however,
belongs to the most recent PTU of all the declarations in its signature - mostly
that means that it can be pulled into a more recent PTU by its template
arguments.

The second key insight is that processing a PTU might extend an earlier PTU.
Rolling back the later PTU shouldn't throw that extension away. For example, if
the second PTU defines a template, and the third PTU requires that template to
be instantiated at float, that template specialization is still part of the
second PTU. Similarly, if the fifth PTU uses an inline function belonging to the
fourth, that definition still belongs to the fourth. When we go to emit code in
a new PTU, we map each declaration we have to emit back to its owning PTU and
emit it in a new module for just the extensions to that PTU. We keep track of
all the modules we've emitted for a PTU so that we can unload them all if we
decide to roll it back.

Most declarations/definitions will only refer to entities from the same or
earlier PTUs. However, it is possible (primarily by defining a
previously-declared entity, but also through templates or ADL) for an entity
that belongs to one PTU to refer to something from a later PTU. We will have to
keep track of this and prevent unwinding to later PTU when we recognize it.
Fortunately, this should be very rare; and crucially, we don't have to do the
bookkeeping for this if we've only got one PTU, e.g. in normal compilation.
Otherwise, PTUs after the first just need to record enough metadata to be able
to revert any changes they've made to declarations belonging to earlier PTUs,
e.g. to redeclaration chains or template specialization lists.

It should even eventually be possible for PTUs to provide their own slab
allocators which can be thrown away as part of rolling back the PTU. We can
maintain a notion of the active allocator and allocate things like Stmt/Expr
nodes in it, temporarily changing it to the appropriate PTU whenever we go to do
something like instantiate a function template. More care will be required when
allocating declarations and types, though.

We would want the PTU to be efficiently recoverable from a Decl; I'm not sure
how best to do that. An easy option that would cover most declarations would be
to make multiple TranslationUnitDecls and parent the declarations appropriately,
but I don't think that's good enough for things like member function templates,
since an instantiation of that would still be parented by its original class.
Maybe we can work this into the DC chain somehow, like how lexical DCs are.

We add a different kind of translation unit `TU_Incremental` which is a
complete translation unit that we might nonetheless incrementally extend later.
Because it is complete (and we might want to generate code for it), we do
perform template instantiation, but because it might be extended later, we don't
warn if it declares or uses undefined internal-linkage symbols.

This patch teaches clang-repl how to recover from errors by disconnecting the
most recent PTU and update the primary PTU lookup tables. For instance:

```./clang-repl
clang-repl> int i = 12; error;
In file included from <<< inputs >>>:1:
input_line_0:1:13: error: C++ requires a type specifier for all declarations
int i = 12; error;
            ^
error: Parsing failed.
clang-repl> int i = 13; extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=13
clang-repl> quit
```

Differential revision: https://reviews.llvm.org/D104918
2021-07-12 15:21:22 +00:00
Vassil Vassilev 5922f234c8 Revert "[clang-repl] Implement partial translation units and error recovery."
This reverts commit 6775fc6ffa.

It also reverts "[lldb] Fix compilation by adjusting to the new ASTContext signature."

This reverts commit 03a3f86071.

We see some failures on the lldb infrastructure, these changes might play a role
in it. Let's revert it now and see if the bots will become green.

Ref: https://reviews.llvm.org/D104918
2021-07-11 14:40:10 +00:00
Vassil Vassilev 6775fc6ffa [clang-repl] Implement partial translation units and error recovery.
https://reviews.llvm.org/D96033 contained a discussion regarding efficient
modeling of error recovery. @rjmccall has outlined the key ideas:

Conceptually, we can split the translation unit into a sequence of partial
translation units (PTUs). Every declaration will be associated with a unique PTU
that owns it.

The first key insight here is that the owning PTU isn't always the "active"
(most recent) PTU, and it isn't always the PTU that the declaration
"comes from". A new declaration (that isn't a redeclaration or specialization of
anything) does belong to the active PTU. A template specialization, however,
belongs to the most recent PTU of all the declarations in its signature - mostly
that means that it can be pulled into a more recent PTU by its template
arguments.

The second key insight is that processing a PTU might extend an earlier PTU.
Rolling back the later PTU shouldn't throw that extension away. For example, if
the second PTU defines a template, and the third PTU requires that template to
be instantiated at float, that template specialization is still part of the
second PTU. Similarly, if the fifth PTU uses an inline function belonging to the
fourth, that definition still belongs to the fourth. When we go to emit code in
a new PTU, we map each declaration we have to emit back to its owning PTU and
emit it in a new module for just the extensions to that PTU. We keep track of
all the modules we've emitted for a PTU so that we can unload them all if we
decide to roll it back.

Most declarations/definitions will only refer to entities from the same or
earlier PTUs. However, it is possible (primarily by defining a
previously-declared entity, but also through templates or ADL) for an entity
that belongs to one PTU to refer to something from a later PTU. We will have to
keep track of this and prevent unwinding to later PTU when we recognize it.
Fortunately, this should be very rare; and crucially, we don't have to do the
bookkeeping for this if we've only got one PTU, e.g. in normal compilation.
Otherwise, PTUs after the first just need to record enough metadata to be able
to revert any changes they've made to declarations belonging to earlier PTUs,
e.g. to redeclaration chains or template specialization lists.

It should even eventually be possible for PTUs to provide their own slab
allocators which can be thrown away as part of rolling back the PTU. We can
maintain a notion of the active allocator and allocate things like Stmt/Expr
nodes in it, temporarily changing it to the appropriate PTU whenever we go to do
something like instantiate a function template. More care will be required when
allocating declarations and types, though.

We would want the PTU to be efficiently recoverable from a Decl; I'm not sure
how best to do that. An easy option that would cover most declarations would be
to make multiple TranslationUnitDecls and parent the declarations appropriately,
but I don't think that's good enough for things like member function templates,
since an instantiation of that would still be parented by its original class.
Maybe we can work this into the DC chain somehow, like how lexical DCs are.

We add a different kind of translation unit `TU_Incremental` which is a
complete translation unit that we might nonetheless incrementally extend later.
Because it is complete (and we might want to generate code for it), we do
perform template instantiation, but because it might be extended later, we don't
warn if it declares or uses undefined internal-linkage symbols.

This patch teaches clang-repl how to recover from errors by disconnecting the
most recent PTU and update the primary PTU lookup tables. For instance:

```./clang-repl
clang-repl> int i = 12; error;
In file included from <<< inputs >>>:1:
input_line_0:1:13: error: C++ requires a type specifier for all declarations
int i = 12; error;
            ^
error: Parsing failed.
clang-repl> int i = 13; extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=13
clang-repl> quit
```

Differential revision: https://reviews.llvm.org/D104918
2021-07-11 10:23:41 +00:00
Peter Collingbourne e655e74a31 AST: Create __va_list in the std namespace even in C.
This ensures that the mangled type names match between C and C++,
which is significant when using -fsanitize=cfi-icall. Ideally we
wouldn't have created this namespace at all, but it's now part of
the ABI (e.g. in mangled names), so we can't change it.

Differential Revision: https://reviews.llvm.org/D104830
2021-06-23 18:59:10 -07:00
Nathan Sidwell b2d0c16e91 [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
2021-06-08 11:11:46 -07:00
Erich Keane d8e0ae9a76 [SYCL] Fix __builtin_sycl_unique_stable_name to work on windows/spir
In the case where the device is an itanium target, and the host is a
windows target, we were getting the names wrong, since in the itanium
case we filter by lambda-signature.

The fix is to always filter by the signature rather than just on
non-windows builds. I considered doing the reverse (that is, checking
the aux-triple), but doing so would result in duplicate lambda mangling
numbers (from linux reusing the same number for different signatures).
2021-06-02 13:16:14 -07:00
Erich Keane cb66bf2c6d Replace 'magic static' with a member variable for SCYL kernel names
I discovered when merging the __builtin_sycl_unique_stable_name into my
downstream that it is actually possible for the cc1 invocation to have
more than 1 Sema instance, if you pass it multiple input files, each
gets its own Sema instance and thus ASTContext instance.  The result was
that the call to Filter the SYCL kernels was using an
ItaniumMangleContext stored via a 'magic static', so it had an invalid
reference to ASTContext when processing the 2nd failure.

The failure is unfortunately flakey/transient, but the test that fails
was added anyway.

The magic-static was switched to a unique_ptr member variable in
ASTContext that is initialized when needed.
2021-05-27 13:46:31 -07:00