- Change FlattenedSpelling to use StringRef instead of std::String.
- Use range for loops and enumerate().
- Use ArrayRef<> instead of std::vector reference as function arguments.
- Use {} for all if/else branch bodies if one of them uses it.
By allowing AnnotateAttr to be applied to statements, users can place arbitrary information in the AST for later use.
For example, this can be used for HW-targeted language extensions that involve specialized loop annotations.
Split RecordKeeper `getAllDerivedDefinitions` family of functions into
two variants:
(a) non-const ones that return vectors of `Record *` and
(b) const ones, that return vector/ArrayRef of `const Record *`.
This will help gradual migration of TableGen backends to use
`const RecordKeeper` and by implication change code to work
with const pointers and better const correctness.
Existing backends are not yet compatible with the const family of
functions, so change them to use a non-constant `RecordKeeper`
reference, till they are migrated.
In 2acf77f987 code was added to use the
'full' name including syntax and scope.
Instead of building up a large string for each name, add syntax and
scope checks to the value expression in tablegen.
There is already code to generate expressions for target specific
attributes. This change refactors and adds to that code to include
syntax and scope checks.
The tablegen avoids generating the complicated expression unless there
are two attributes using the same name, otherwise the case values will
be as simple as before.
Removes the currently unused attributeHasStrictIdentifierArgAtIndex
function and the related tablegen.
In 92fc1eb0c1 the HLSLLoopHint attribute
was added with an 'unroll' spelling. There is an existing LoopHint
attribute with the same spelling. These attributes have different
arguments.
The tablegen used to produce checks on arguments uses only the attribute
name, making it impossible to return correct info for attribute with
different argument types but the same name.
Improve the situation by using a 'full' name that combines the syntax,
scope, and name. This allows, for example, #pragma unroll and
[[unroll(x)]] to coexist correctly even with different argument types.
Also fix a bug in the StrictEnumParameters tablegen. If will now
correctly specify each parameter instead of only the first.
Since `raw_string_ostream` doesn't own the string buffer, it is
desirable (in terms of memory safety) for users to directly reference
the string buffer rather than use `raw_string_ostream::str()`.
Work towards TODO item to remove `raw_string_ostream::str()`.
Virtual function pointer entries in v-tables are signed with address
discrimination in addition to declaration-based discrimination, where an
integer discriminator the string hash (see
`ptrauth_string_discriminator`) of the mangled name of the overridden
method. This notably provides diversity based on the full signature of
the overridden method, including the method name and parameter types.
This patch introduces ItaniumVTableContext logic to find the original
declaration of the overridden method.
On AArch64, these pointers are signed using the `IA` key (the
process-independent code key.)
V-table pointers can be signed with either no discrimination, or a
similar scheme using address and decl-based discrimination. In this
case, the integer discriminator is the string hash of the mangled
v-table identifier of the class that originally introduced the vtable
pointer.
On AArch64, these pointers are signed using the `DA` key (the
process-independent data key.)
Not using discrimination allows attackers to simply copy valid v-table
pointers from one object to another. However, using a uniform
discriminator of 0 does have positive performance and code-size
implications on AArch64, and diversity for the most important v-table
access pattern (virtual dispatch) is already better assured by the
signing schemas used on the virtual functions. It is also known that
some code in practice copies objects containing v-tables with `memcpy`,
and while this is not permitted formally, it is something that may be
invasive to eliminate.
This is controlled by:
```
-fptrauth-vtable-pointer-type-discrimination
-fptrauth-vtable-pointer-address-discrimination
```
In addition, this provides fine-grained controls in the
ptrauth_vtable_pointer attribute, which allows overriding the default
ptrauth schema for vtable pointers on a given class hierarchy, e.g.:
```
[[clang::ptrauth_vtable_pointer(no_authentication, no_address_discrimination,
no_extra_discrimination)]]
[[clang::ptrauth_vtable_pointer(default_key, default_address_discrimination,
custom_discrimination, 0xf00d)]]
```
The override is then mangled as a parametrized vendor extension:
```
"__vtptrauth" I
<key>
<addressDiscriminated>
<extraDiscriminator>
E
```
To support this attribute, this patch adds a small extension to the
attribute-emitter tablegen backend.
Note that there are known areas where signing is either missing
altogether or can be strengthened. Some will be addressed in later
changes (e.g., member function pointers, some RTTI).
`dynamic_cast` in particular is handled by emitting an artificial
v-table pointer load (in a way that always authenticates it) before the
runtime call itself, as the runtime doesn't have enough information
today to properly authenticate it. Instead, the runtime is currently
expected to strip the v-table pointer.
---------
Co-authored-by: John McCall <rjmccall@apple.com>
Co-authored-by: Ahmed Bougacha <ahmed@bougacha.org>
The resource class isn't HLSL specific, and we'll need to use it in the
DirectX backend as well.
I've also removed the "invalid" enum value since it isn't needed or
used, which necessitates fixing up the clang attr emitter to handle
external enum types that are fully covered by the attribute.
Now we can create a LocalDeclID directly with an integer without
verifying. It may be hard to refactor if we want to change the way we
serialize DeclIDs (See https://github.com/llvm/llvm-project/pull/95897).
Also it is hard for us to debug if someday someone construct a
LocalDeclID with an incorrect value.
So in this patch, I tried to unify the way we can construct a
LocalDeclID in ASTReader, where we will construct the LocalDeclID from
the serialized data. Also, now we can verify the constructed LocalDeclID
sooner in the new interface.
This patch changes the `LateParsed` field of `Attr` in `Attr.td` to be
an instantiation of the new `LateAttrParseKind` class. The instation can be one of the following:
* `LateAttrParsingNever` - Corresponds with the false value of `LateParsed` prior to this patch (the default for an attribute).
* `LateAttrParseStandard` - Corresponds with the true value of `LateParsed` prior to this patch.
* `LateAttrParseExperimentalExt` - A new mode described below.
`LateAttrParseExperimentalExt` is an experimental extension to
`LateAttrParseStandard`. Essentially this allows
`Parser::ParseGNUAttributes(...)` to distinguish between these cases:
1. Only `LateAttrParseExperimentalExt` attributes should be late parsed.
2. Both `LateAttrParseExperimentalExt` and `LateAttrParseStandard`
attributes should be late parsed.
Callers (and indirect callers) of `Parser::ParseGNUAttributes(...)`
indicate the desired behavior by setting a flag in the
`LateParsedAttrList` object that is passed to the function.
In addition to the above, a new driver and frontend flag
(`-fexperimental-late-parse-attributes`) with a corresponding LangOpt
(`ExperimentalLateParseAttributes`) is added that changes how
`LateAttrParseExperimentalExt` attributes are parsed.
* When the flag is disabled (default), in cases where only
`LateAttrParsingExperimentalOnly` late parsing is requested, the
attribute will be parsed immediately (i.e. **NOT** late parsed). This
allows the attribute to act just like a `LateAttrParseStandard`
attribute when the flag is disabled.
* When the flag is enabled, in cases where only
`LateAttrParsingExperimentalOnly` late parsing is requested, the
attribute will be late parsed.
The motivation behind this change is to allow the new `counted_by`
attribute (part of `-fbounds-safety`) to support late parsing but
**only** when `-fexperimental-late-parse-attributes` is enabled. This
attribute needs to support late parsing to allow it to refer to fields
later in a struct definition (or function parameters declared later).
However, there isn't a precedent for supporting late attribute parsing
in C so this flag allows the new behavior to exist in Clang but not be
on by default. This behavior was requested as part of the
`-fbounds-safety` RFC process
(https://discourse.llvm.org/t/rfc-enforcing-bounds-safety-in-c-fbounds-safety/70854/68).
This patch doesn't introduce any uses of `LateAttrParseExperimentalExt`.
This will be added for the `counted_by` attribute in a future patch
(https://github.com/llvm/llvm-project/pull/87596). A consequence is the
new behavior added in this patch is not yet testable. Hence, the lack of
tests covering the new behavior.
rdar://125400257
Previously, the LocalDeclID and GlobalDeclID are defined as:
```
using LocalDeclID = DeclID;
using GlobalDeclID = DeclID;
```
This is more or less concerning that we may misuse LocalDeclID and
GlobalDeclID without understanding it. There is also a FIXME saying
this.
This patch tries to turn LocalDeclID into a class to improve the type
safety here.
The attribute name "HLSLSemantics" is confusing, because semantics
aren't always the annotation that are applied to specific variables. The
name for this attribute needs to be less specific. This PR changes the
attribute name from HLSLSemantic to HLSLAnnotation, and changes the
associated function and variable names to support this conceptual
change.
The HLSLAnnotation attribute will never be output in ast-dump due to it
being parsed for the attribute that it represents. There is no
functional change, so there are no accompanying tests.
Original commit message:
"
Commit https://github.com/llvm/llvm-project/commit/46f3ade introduced a notion
of printing the attributes on the left to improve the printing of attributes
attached to variable declarations. The intent was to produce more GCC compatible
code because clang tends to print the attributes on the right hand side which is
not accepted by gcc.
This approach has increased the complexity in tablegen and the attrubutes
themselves as now the are supposed to know where they could appear. That lead to
mishandling of the `override` keyword which is modelled as an attribute in
clang.
This patch takes an inspiration from the existing approach and tries to keep the
position of the attributes as they were written. To do so we use simpler
heuristic which checks if the source locations of the attribute precedes the
declaration. If so, it is considered to be printed before the declaration.
Fixes https://github.com/llvm/llvm-project/issues/87151
"
The reason for the bot breakage is that attributes coming from ApiNotes are not
marked implicit even though they do not have source locations. This caused an
assert to trigger. This patch forces attributes with no source location
information to be printed on the left. That change is consistent to the overall
intent of the change to increase the chances for attributes to compile across
toolchains and at the same time the produced code to be as close as possible to
the one written by the user.
Commit https://github.com/llvm/llvm-project/commit/46f3ade introduced a
notion of printing the attributes on the left to improve the printing of
attributes attached to variable declarations. The intent was to produce
more GCC compatible code because clang tends to print the attributes on
the right hand side which is not accepted by gcc.
This approach has increased the complexity in tablegen and the
attrubutes themselves as now the are supposed to know where they could
appear. That lead to mishandling of the `override` keyword which is
modelled as an attribute in clang.
This patch takes an inspiration from the existing approach and tries to
keep the position of the attributes as they were written. To do so we
use simpler heuristic which checks if the source locations of the
attribute precedes the declaration. If so, it is considered to be
printed before the declaration.
Fixes https://github.com/llvm/llvm-project/issues/87151
The values for `__has_cpp_attribute` don't have to be guarded behind
`LangOpts.CPlusPlus` because `__has_cpp_attribute` isn't available if
Clang isn't in a C++ mode.
Fixes#82995
EnumArgument may be a string or an identifier. If it is a string, it
should be parsed as unevaluated string literal. Add IsString flag to
EnumArgument so that the parser can choose the correct parsing method.
Target-specific attributes that share spelling may have different
attribute "prototypes". For example, ARM's version of "interrupt"
attribute accepts a string enum, while MSP430's version accepts an
unsigned integer. Adjust ClangAttrEmitter so that the generated
`attributeStringLiteralListArg` returns the correct mask depending on
target triple.
It is worth noting that even after this change some string arguments are
still parsed as identifiers or, worse, as expressions. This is because
of some special logic in `ParseAttributeArgsCommon`. Fixing it is out of
scope of this patch.
GCC 14 defines `__arm_streaming` as a macro expanding to
`[[arm::streaming]]`. Due to the nested macro use, this gets expanded
prior to concatenation.
It doesn't look like C++ has a really clean way to prevent macro
expansion. The best I have found is to use `EMPTY ## X` where `EMPTY` is
an empty macro argument, so this is the hack I'm implementing here.
Fixes https://github.com/llvm/llvm-project/issues/78691.
This upstreams more of the Clang API Notes functionality that is
currently implemented in the Apple fork:
https://github.com/apple/llvm-project/tree/next/clang/lib/APINotes
This is the largest chunk of the API Notes functionality in the
upstreaming process. I will soon submit a follow-up patch to actually
enable usage of this functionality by having a Clang driver flag that
enables API Notes, along with tests.
This patch replaces the `__arm_new_za`, `__arm_shared_za` and
`__arm_preserves_za` attributes in favour of:
* `__arm_new("za")`
* `__arm_in("za")`
* `__arm_out("za")`
* `__arm_inout("za")`
* `__arm_preserves("za")`
As described in https://github.com/ARM-software/acle/pull/276.
One change is that `__arm_in/out/inout/preserves(S)` are all mutually
exclusive, whereas previously it was fine to write `__arm_shared_za
__arm_preserves_za`. This case is now represented with `__arm_in("za")`.
The current implementation uses the same LLVM attributes under the hood,
since `__arm_in/out/inout` are all variations of "shared ZA", so can use
the existing `aarch64_pstate_za_shared` attribute in LLVM.
#77941 will add support for the new "zt0" state as introduced
with SME2.
Rather than write a bunch of logic to shepherd between enums with the
same sets of values, add the ability for EnumArgument to refer to an
external enum in the first place.
1. The generated file contained a lot of duplicate switch cases, e.g.:
```
switch (Syntax) {
case AttributeCommonInfo::Syntax::AS_GNU:
return llvm::StringSwitch<int>(Name)
...
.Case("error", 1)
.Case("warning", 1)
.Case("error", 1)
.Case("warning", 1)
```
2. Some attributes were listed in wrong places, e.g.:
```
case AttributeCommonInfo::Syntax::AS_CXX11: {
if (ScopeName == "") {
return llvm::StringSwitch<int>(Name)
...
.Case("warn_unused_result", LangOpts.CPlusPlus11 ? 201907 : 0)
```
`warn_unused_result` is a non-standard attribute and should not be
available as [[warn_unused_result]].
3. Some attributes had the wrong version, e.g.:
```
case AttributeCommonInfo::Syntax::AS_CXX11: {
} else if (ScopeName == "gnu") {
return llvm::StringSwitch<int>(Name)
...
.Case("fallthrough", LangOpts.CPlusPlus11 ? 201603 : 0)
```
[[gnu::fallthrough]] is a non-standard spelling and should not have the
standard version. Instead, __has_cpp_attribute should return 1 for it.
There is another issue with attributes that share spellings, e.g.:
```
.Case("interrupt", true && (T.getArch() == llvm::Triple::arm || ...) ? 1 : 0)
.Case("interrupt", true && (T.getArch() == llvm::Triple::avr) ? 1 : 0)
...
.Case("interrupt", true && (T.getArch() == llvm::Triple::riscv32 || ...) ? 1 : 0)
```
As can be seen, __has_attribute(interrupt) would only return true for
ARM targets. This patch does not address this issue.
Differential Revision: https://reviews.llvm.org/D159393
This implements the [[msvc::no_unique_address]] attribute.
There is not ABI compatibility in this patch because the attribute is
relatively new and there's still some uncertainty in the MSVC version.
The recommit changes the attribute definitions so that instead of making
two separate attributes for no_unique_address
and msvc::no_unique_address, it modifies the attributes tablegen emitter
to allow spellings to be target-specific.
This reverts commit 71f9e7695b.
Inside `writePrettyPrintFunction()`, we check if we need to emit the
given argument:
```C++
if (!arg->isOptional() || arg->getIsOmitted() == "false") {
FoundNonOptArg = true;
continue;
}
```
For the `AssumeAligned` attribute, the second argument was optional, but
the `getIsOmitted()` returned `false`, thus we treated this argument as
**non-optional** in the end because of that disjunction.
It was because `getIsOmitted()` did not account for `Expr *` type, and
returned `false` on the fallthrough branch.
Fixes#67156
Currently there is no PrintOnLeft attribute set, which results in an
empty switch-case. When compiling this, MSVC issues a warning saying
that the switch-case is empty. Fix this by using a macro and checking
if this macro is defined or not.
Links to D157394
Previously clang AST prints the following declaration:
int fun_var_unused() {
int x __attribute__((unused)) = 0;
return x;
}
and
int __declspec(thread) x = 0;
as:
int fun_var_unused() {
int x = 0 __attribute__((unused));
return x;
}
and
int x = __declspec(thread) 0;
which is rejected by C/C++ parser. This patch modifies the logic to
print old C attributes for variables as:
int __attribute__((unused)) x = 0;
and the __declspec case as:
int __declspec(thread) x = 0;
Fixes: https://github.com/llvm/llvm-project/issues/59973
Previous version: D141714.
Differential Revision:https://reviews.llvm.org/D141714
The attributes changes were left out of Clang 17.
Attributes that used to take a string literal now accept an unevaluated
string literal instead, which means they reject numeric escape sequences
and strings literal with an encoding prefix - but the later was already
ill-formed in most cases.
We need to know that we are going to parse an unevaluated string literal
before we do - so we can reject numeric escape sequence,
so we derive from Attrs.td which attributes parameters are expected
to be string literals.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D156237
This does the rename for most internal uses of C2x, but does not rename
or reword diagnostics (those will be done in a follow-up).
I also updated standards references and citations to the final wording
in the standard.
This patch adds the Parse and Sema support for RegularKeyword attributes,
following on from a previous patch that added Attr.td support.
The patch is quite large. However, nothing outside the tests is
specific to the first RegularKeyword attribute (__arm_streaming).
The patch should therefore be a one-off, up-front cost. Other
attributes just need an entry in Attr.td and the usual Sema support.
The approach taken in the patch is that the keywords can be used with
any language version. If standard attributes were added in language
version Y, the keyword rules for version X<Y are the same as they were
for version Y (to the extent possible). Any extensions beyond Y are
handled in the same way for both keywords and attributes. This ensures
that existing C++11 successors like C++17 are not treated differently
from versions that have yet to be defined.
Some notes on the implementation:
* The patch emits errors rather than warnings for diagnostics that
relate to keywords.
* Where possible, the patch drops “attribute” from diagnostics
relating to keywords.
* One exception to the previous point is that warnings about C++
extensions do still mention attributes. The use there seemed OK
since the diagnostics are noting a change in the production rules.
* If a diagnostic string needs to be different for keywords and
attributes, the patch standardizes on passing the attribute/
name/token followed by 0 for attributes and 1 for keywords.
* Although the patch updates warn_attribute_wrong_decl_type_str,
warn_attribute_wrong_decl_type, and warn_attribute_wrong_decl_type,
only the error forms of these strings are used for keywords.
* I couldn't trigger the warnings in checkUnusedDeclAttributes,
even for existing attributes. An assert on the warnings caused
no failures in the testsuite. I think in practice all standard
attributes would be diagnosed before this.
* The patch drops a call to standardAttributesAllowed in
ParseFunctionDeclarator. This is because MaybeParseCXX11Attributes
checks the same thing itself, where appropriate.
* The new tests are based on c2x-attributes.c and
cxx0x-attributes.cpp. The C++ test also incorporates a version of
cxx11-base-spec-attributes.cpp. The FIXMEs are carried across from
the originals.
Differential Revision: https://reviews.llvm.org/D148702
Platform-specific language extensions often want to provide a way of
indicating that certain functions should be called in a different way,
compiled in a different way, or otherwise treated differently from a
“normal” function. Honoring these indications is often required for
correctness, rather being than an optimization/QoI thing.
If a function declaration has a property P that matters for correctness,
it will be ODR-incompatible with a function that does not have property P.
If a function type has a property P that affects the calling convention,
it will not be two-way compatible with a function type that does not
have property P. These properties therefore affect language semantics.
That in turn means that they cannot be treated as standard [[]]
attributes.
Until now, many of these properties have been specified using GNU-style
attributes instead. GNU attributes have traditionally been more lax
than standard attributes, with many of them having semantic meaning.
Examples include calling conventions and the vector_size attribute.
However, there is a big drawback to using GNU attributes for semantic
information: compilers that don't understand the attributes will
(by default) emit a warning rather than an error. They will go on to
compile the code as though the attributes weren't present, which will
inevitably lead to wrong code in most cases. For users who live
dangerously and disable the warning, this wrong code could even be
generated silently.
A more robust approach would be to specify the properties using
keywords, which older compilers would then reject. Some vendor-specific
extensions have already taken this approach. But traditionally, each
such keyword has been treated as a language extension in its own right.
This has three major drawbacks:
(1) The parsing rules need to be kept up-to-date as the language evolves.
(2) There are often corner cases that similar extensions handle differently.
(3) Each extension requires more custom code than a standard attribute.
The underlying problem for all three is that, unlike for true attributes,
there is no established template that extensions can reuse. The purpose
of this patch series is to try to provide such a template.
One option would have been to pick an existing keyword and do whatever
that keyword does. The problem with that is that most keywords only
apply to specific kinds of types, kinds of decls, etc., and so the
parsing rules are (for good reason) not generally applicable to all
types and decls.
Really, the “only” thing wrong with using standard attributes is that
standard attributes cannot affect semantics. In all other respects
they provide exactly what we need: a well-defined grammar that evolves
with the language, clear rules about what an attribute appertains to,
and so on.
This series therefore adds keyword “attributes” that can appear
exactly where a standard attribute can appear and that appertain
to exactly what a standard attribute would appertain to. The link is
mechanical and no opt-outs or variations are allowed. This should
make the keywords predictable for programmers who are already
familiar with standard attributes.
This does mean that these keywords will be accepted for parsing purposes
in many more places than necessary. Inappropriate uses will then be
diagnosed during semantic analysis. However, the compiler would need
to reject the keywords in those positions whatever happens, and treating
them as ostensible attributes shouldn't be any worse than the alternative.
In some cases it might even be better. For example, SME's
__arm_streaming attribute would make conceptual sense as a statement
attribute, so someone who takes a “try-it-and-see” approach might write:
__arm_streaming { …block-of-code…; }
In fact, we did consider supporting this originally. The reason for
rejecting it was that it was too difficult to implement, rather than
because it didn't make conceptual sense.
One slight disadvantage of the keyword-based approach is that it isn't
possible to use #pragma clang attribute with the keywords. Perhaps we
could add support for that in future, if it turns out to be useful.
For want of a better term, I've called the new attributes "regular"
keyword attributes (in the sense that their parsing is regular wrt
standard attributes), as opposed to "custom" keyword attributes that
have their own parsing rules.
This patch adds the Attr.td support for regular keyword attributes.
Adding an attribute with a RegularKeyword spelling causes tablegen
to define the associated tokens and to record that attributes created
with that syntax are regular keyword attributes rather than custom
keyword attributes.
A follow-on patch contains the main Parse and Sema support,
which is enabled automatically by the Attr.td definition.
Other notes:
* The series does not allow regular keyword attributes to take
arguments, but this could be added in future.
* I wondered about trying to use tablegen for
TypePrinter::printAttributedAfter too, but decided against it.
RegularKeyword is really a spelling-level classification rather
than an attribute-level classification, and in general, an attribute
could have both GNU and RegularKeyword spellings. In contrast,
printAttributedAfter is only given the attribute kind and the type
that results from applying the attribute. AFAIK, it doesn't have
access to the original attribute spelling. This means that some
attribute-specific or type-specific knowledge might be needed
to print the attribute in the best way.
* Generating the tokens automatically from Attr.td means that
pseudo's libgrammar does now depend on tablegen.
* The patch uses the SME __arm_streaming attribute as an example
for testing purposes. The attribute does not do anything at this
stage. Later SME-specific patches will add proper semantics for it,
and add other SME-related keyword attributes.
Differential Revision: https://reviews.llvm.org/D148700
Reported by Coverity:
AUTO_CAUSES_COPY
Unnecessary object copies can affect performance.
1. Inside "SemaDeclCXX.cpp" file, in <unnamed>::DiagnoseUninitializedFields(clang::Sema &, clang::CXXConstructorDecl const *): Using the auto keyword without an & causes the copy of an object of type CXXBaseSpecifier.
2. Inside "ClangAttrEmitter.cpp" file, in clang::EmitClangAttrParsedAttrImpl(llvm::RecordKeeper &, llvm::raw_ostream &): Using the auto keyword without an & causes the copy of an object of type pair.
3. Inside "Marshallers.h" file, in clang::ast_matchers::dynamic::internal::MapAnyOfBuilderDescriptor::buildMatcherCtor(clang::ast_matchers::dynamic::SourceRange, llvm::ArrayRef<clang::ast_matchers::dynamic::ParserValue>, clang::ast_matchers::dynamic::Diagnostics *): Using the auto keyword without an & causes the copy of an object of type ParserValue.
4. Inside "CGVTables.cpp" file, in clang::CodeGen::CodeGenModule::GetVCallVisibilityLevel(clang::CXXRecordDecl const *, llvm::DenseSet<clang::CXXRecordDecl const *, llvm::DenseMapInfo<clang::CXXRecordDecl const *, void>> &): Using the auto keyword without an & causes the copy of an object of type CXXBaseSpecifier.
5. Inside "ASTContext.cpp" file, in hasTemplateSpecializationInEncodedString(clang::Type const *, bool): Using the auto keyword without an & causes the copy of an object of type CXXBaseSpecifier.
6. Inside "ComputeDependence.cpp" file, in clang::computeDependence(clang::DependentScopeDeclRefExpr *): Using the auto keyword without an & causes the copy of an object of type TemplateArgumentLoc.
Reviewed By: tahonermann, erichkeane
Differential Revision: https://reviews.llvm.org/D148812
AttributeCommonInfo::isAlignasAttribute() was used in one place:
isCXX11Attribute(). The intention was for isAlignasAttribute()
to return true for the C++ alignas keyword. However, as a FIXME
noted, the function also returned true for the C _Alignas keyword.
This meant that isCXX11Attribute() returned true for _Alignas as
well as for alignas.
AttributeCommonInfos are now always constructed with an
AttributeCommonInfo::Form. We can use that Form to convey whether
a keyword is alignas or not.
The patch uses 1 bit of an 8-bit hole in the current layout
of AttributeCommonInfo. This might not be the best long-term design,
but it should be easy to adapt the layout if necessary (that is,
if other uses are found for the spare bits).
I don't know of a way of testing this (other than grep -c FIXME)
Differential Revision: https://reviews.llvm.org/D148105
