...when looking for a template instantiation with a non-type parameter of
unknown type and with a default value.
This can happen when a template non-type parameter has a broken
expression that gets replaced by a `RecoveryExpr`.
This patch addresses static analyzer concern where TSI could be
dereferenced after being assigned a null value from SubstType in
clang::TemplateDeclInstantiator::VisitUsingEnumDecl(clang::UsingEnumDecl
*).
The fix now checks null value of TSI after the call to SubstType and
return nullptr to prevent potential null pointer dereferences when
calling UsingEnumDecl::Create() and ensures safe execution.
Similar to the approach of handling nested class templates when building
a CTAD guide, we substitute the template parameters of a type alias
declaration with the instantiating template arguments in order to ensure
the guide eventually doesn't reference any outer template parameters.
For example,
```cpp
template <class T> struct Outer {
using Alias = S<T>;
template <class U> struct Inner {
Inner(Alias);
};
};
```
we used to retain the reference to T accidentally because the
TreeTransform does nothing on type alias Decls by default.
Fixes https://github.com/llvm/llvm-project/issues/94614
The noexcept specifiers of dependent lambdas would be transformed and
rebuilt, where the map of instantiation should also contain captured
variables in case they are used from the noexcept specifier.
I also uncovered another assertion failure while at it. However, I
decided to leave it as-is because 1) that doesn't appear to be the case
in the release version and 2) fixing that might lead to ABI breakage.
Anyhow, the case has been added to the test comment.
Fixes https://github.com/llvm/llvm-project/issues/95735
This patch moves documentation of `Sema` functions from `.cpp` files to `Sema.h` when there was no documentation in the latter, or it can be trivially subsumed. More complicated cases when there's less trivial divergence between documentation attached to declaration and the one attached to implementation are left for a later PR that would require review.
It appears that doxygen can find the documentation for a function defined out-of-line even if it's attached to an implementation, and not declaration. But other tools, e.g. clangd, are not as powerful. So this patch significantly improves autocompletion experience for (at least) clangd-based IDEs.
This patch moves language- and target-specific functions out of
`SemaDeclAttr.cpp`. As a consequence, `SemaAVR`, `SemaM68k`,
`SemaMSP430`, `SemaOpenCL`, `SemaSwift` were created (but they are not
the only languages and targets affected).
Notable things are that `Sema.h` actually grew a bit, because of
templated helpers that rely on `Sema` that I had to make available from
outside of `SemaDeclAttr.cpp`. I also had to left CUDA-related in
`SemaDeclAttr.cpp`, because it looks like HIP is building up on top of
CUDA attributes.
This is a follow-up to #93179 and continuation of efforts to split
`Sema` up. Additional context can be found in #84184 and #92682.
This patch introduces `SemaAMDGPU`, `SemaARM`, `SemaBPF`, `SemaHexagon`,
`SemaLoongArch`, `SemaMIPS`, `SemaNVPTX`, `SemaPPC`, `SemaSystemZ`,
`SemaWasm`. This continues previous efforts to split Sema up. Additional
context can be found in #84184 and #92682.
I decided to bundle target-specific components together because of their
low impact on `Sema`. That said, their impact on `SemaChecking.cpp` is
far from low, and I consider it a success.
Somewhat accidentally, I also moved Wasm- and AMDGPU-specific function
from `SemaDeclAttr.cpp`, because they were exposed in `Sema`. That went
well, and I consider it a success, too. I'd like to move the rest of
static target-specific functions out of `SemaDeclAttr.cpp` like we're
doing with built-ins in `SemaChecking.cpp` .
Fixes#71161
[D64087](https://reviews.llvm.org/D64087) updated some locations of the
instantiated method but forgot `DNLoc`.
`FunctionDecl::getNameInfo()` constructs a `DeclarationNameInfo` using
`Decl::Loc` as the beginning of the declaration name, and
`FunctionDecl::DNLoc` to compute the end of the declaration name. The
former was updated, but the latter was not, so
`DeclarationName::getSourceRange()` would return a range where the end
of the declaration name could come before its beginning.
Patch by Alejandro Alvarez Ayllon
Co-authored-by: steakhal
CPP-5166
Co-authored-by: Alejandro Alvarez Ayllon <alejandro.alvarez@sonarsource.com>
This is an enabler for https://github.com/llvm/llvm-project/pull/92855
This allows an NTTP default argument to be set as an arbitrary
TemplateArgument, not just an expression.
This allows template parameter packs to have default arguments in the
AST, even though the language proper doesn't support the syntax for it.
This allows NTTP default arguments to be other kinds of arguments, like
packs, integral constants, and such.
This is an enabler for a future patch.
This allows an type-parameter default argument to be set as an arbitrary
TemplateArgument, not just a type.
This allows template parameter packs to have default arguments in the
AST, even though the language proper doesn't support the syntax for it.
This will be used in a later patch which synthesizes template parameter
lists with arbitrary default arguments taken from template
specializations.
There are a few places we used SubsType, because we only had a type, now
we use SubstTemplateArgument.
SubstTemplateArgument was missing arguments for setting Instantiation
location and entity names.
Adding those is needed so we don't regress in diagnostics.
The following snippet causes a crash:
```
template<typename T>
struct A
{
bool operator<=>(const A&) const requires true = default;
};
bool f(A<int> a)
{
return a != A<int>();
}
```
This occurs because during the rewrite from `operator<=>` to
`operator==`, the "pattern" `operator<=>` function is set as the
instantiated from function for the newly created `operator==` function.
This is obviously incorrect, and this patch fixes it.
Our current method of storing the template arguments as written for
`(Class/Var)Template(Partial)SpecializationDecl` suffers from a number
of flaws:
- We use `TypeSourceInfo` to store `TemplateArgumentLocs` for class
template/variable template partial/explicit specializations. For
variable template specializations, this is a rather unintuitive hack (as
we store a non-type specialization as a type). Moreover, we don't ever
*need* the type as written -- in almost all cases, we only want the
template arguments (e.g. in tooling use-cases).
- The template arguments as written are stored in a number of redundant
data members. For example, `(Class/Var)TemplatePartialSpecialization`
have their own `ArgsAsWritten` member that stores an
`ASTTemplateArgumentListInfo` (the template arguments).
`VarTemplateSpecializationDecl` has yet _another_ redundant member
"`TemplateArgsInfo`" that also stores an `ASTTemplateArgumentListInfo`.
This patch eliminates all
`(Class/Var)Template(Partial)SpecializationDecl` members which store the
template arguments as written, and turns the `ExplicitInfo` member into
a `llvm::PointerUnion<const ASTTemplateArgumentListInfo*,
ExplicitInstantiationInfo*>` (to avoid unnecessary allocations when the
declaration isn't an explicit instantiation). The template arguments as
written are now accessed via `getTemplateArgsWritten` in all cases.
The "most breaking" change is to AST Matchers, insofar that `hasTypeLoc`
will no longer match class template specializations (since they no
longer store the type as written).
In the lambda function within
clang::Sema::InstantiateFunctionDefinition, the return value of a
function that may return null is now checked before dereferencing to
avoid potential null pointer dereference issues which can lead to
crashes or undefined behavior in the program.
Reapplies #87541 and #88311 (again) addressing the bug which caused
expressions naming overload sets to be incorrectly rebuilt, as well as
the bug which caused base class members to always be treated as overload
sets.
The primary change since #88311 is `UnresolvedLookupExpr::Create` is called directly in `BuildPossibleImplicitMemberExpr` with `KnownDependent` as `true` (which causes the expression type to be set to `ASTContext::DependentTy`). This ensures that any further semantic analysis involving the type of the potentially implicit class member access expression is deferred until instantiation.
This patch converts the enum into scoped enum, and moves it into its own header for the time being. It's definition is needed in `Sema.h`, and is going to be needed in upcoming `SemaObjC.h`. `Lookup.h` can't hold it, because it includes `Sema.h`.
This PR remove `InMaterializeTemporaryObjectContext` , because it's
redundant, materialize non-cv void prvalue temporaries in discarded
expressions can only appear under lifetime-extension context.
Signed-off-by: yronglin <yronglin777@gmail.com>
This patch adds a `Typename` bit-field to `TemplateTemplateParmDecl`
which stores whether the template template parameter was declared with
the `typename` keyword.
This patch fixes a crash that happens when '`this`' is referenced
(implicitly or explicitly) in a dependent class scope function template
specialization that instantiates to a static member function. For
example:
```
template<typename T>
struct A
{
template<typename U>
static void f();
template<>
void f<int>()
{
this; // causes crash during instantiation
}
};
template struct A<int>;
```
This happens because during instantiation of the function body,
`Sema::getCurrentThisType` will return a null `QualType` which we
rebuild the `CXXThisExpr` with. A similar problem exists for implicit
class member access expressions in such contexts (which shouldn't really
happen within templates anyways per [class.mfct.non.static]
p2, but changing that is non-trivial). This patch fixes the crash by building
`UnresolvedLookupExpr`s instead of `MemberExpr`s for these implicit
member accesses, which will then be correctly rebuilt as `MemberExpr`s
during instantiation.
I forgot to tidy up these lines that should've been done in the previous
commit, specifically:
1. Merge two `CodeSynthesisContext`s into one in `CheckTemplateIdType`.
2. Remove some gratuitous `Sema::` specifiers.
3. Rename the parameter `Template` to `Entity` to avoid confusion.
Try to fix https://github.com/llvm/llvm-project/issues/84368
When visiting class members in
`TemplateDeclInstantiator::VisitClassTemplateDecl` during
`Sema::InstantiateClass`, we miss to set attribute of friend declaration
if it is(`isFriend` is true). This will lead to
`Sema::AreConstraintExpressionsEqual` return false when invoked in
`MatchTemplateParameterKind`. Because it makes
`Sema::getTemplateInstantiationArgs` returns incorrect template
argument(`MultiLevelTemplateArgumentList`). When we handle
`CXXRecordDecl` In `Sema::getTemplateInstantiationArgs`, friend
declaration(its parent context is `FileContext`) makes us to choose
`LexicalDeclContext` not `DeclContext` and this is what we want.
Co-authored-by: huqizhi <836744285@qq.com>
A new function attribute named amdgpu_num_work_groups is added. This
attribute, which consists of three integers, allows programmers to let
the compiler know the number of workgroups to be launched in each of the
three dimensions and do optimizations based on that information.
---------
Co-authored-by: Jun Wang <jun.wang7@amd.com>
Fixes#54051
This patch implements the C++20 feature -- CTAD for alias templates (P1814R0, specified in https://eel.is/c++draft/over.match.class.deduct#3). It is an initial patch:
- it cover major pieces, thus it works for most cases;
- the big missing piece is to implement the associated constraints (over.match.class.deduct#3.3) for the synthesized deduction guides, see the FIXME in code and tests;
- Some enhancements on the TreeTransform&TemplateInstantiator to allow performing instantiation on `BuildingDeductionGuides` mode;
According to [dcl.type.elab] p4:
> If an _elaborated-type-specifier_ appears with the `friend` specifier
as an entire _member-declaration_, the _member-declaration_ shall have
one of the following forms:
> `friend` _class-key_ _nested-name-specifier_(opt) _identifier_ `;`
> `friend` _class-key_ _simple-template-id_ `;`
> `friend` _class-key_ _nested-name-specifier_ `template`(opt)
_simple-template-id_ `;`
Notably absent from this list is the `enum` form of an
_elaborated-type-specifier_ "`enum` _nested-name-specifier_(opt)
_identifier_", which appears to be intentional per the resolution of
CWG2363.
Most major implementations accept these declarations, so the diagnostic
is a pedantic warning across all C++ versions.
In addition to the trivial cases previously diagnosed in C++98, we now
diagnose cases where the _elaborated-type-specifier_ has a dependent
_nested-name-specifier_:
```
template<typename T>
struct A
{
enum class E;
};
struct B
{
template<typename T>
friend enum A<T>::E; // pedantic warning: elaborated enumeration type cannot be a friend
};
template<typename T>
struct C
{
friend enum T::E; // pedantic warning: elaborated enumeration type cannot be a friend
};
```
This patch removes on-stack `TemplateArgumentList`'s. They were primary used
to pass an `ArrayRef<TemplateArgument>` to
`Sema::getTemplateInstantiationArgs`, which had a `const
TemplateArgumentList*` parameter for the innermost template argument
list. Changing this parameter to an
`std::optional<ArrayRef<TemplateArgument>>` eliminates the need for
on-stack `TemplateArgumentList`'s, which in turn eliminates the need for
`TemplateArgumentList` to store a pointer to its template argument
storage (which is redundant in almost all cases, as it is an AST
allocated type).
We build up a `CXXFoldExpr` for immediately declared constraints as per
C++20 [temp.param]/4. This is done by
`formImmediatelyDeclaredConstraint` where an `EllipsisLoc` is essential
to determine whether this is a pack.
On the other hand, when attempting to instantiate a class template,
member templates might not be instantiated immediately, so we leave them
intact. For function templates with NTTPs, we reattach constraints if
possible so that they can be evaluated later. To properly form that, we
attempted to extract an ellipsis location if the param per se was a
parameter pack. Unfortunately, for the following NTTP case, we seemingly
failed to handle:
```cpp
template <Constraint auto... Pack>
void member();
```
The NTTPD Pack is neither an `ExpandedParameterPack` nor a
`PackExpansion` (its type does not expand anything). As a result, we end
up losing track of the constraints on packs, although we have them
inside the associated `CXXFoldExpr`.
This patch fixes that by extracting the ellipsis location out of the
previous constraint expression. Closes
https://github.com/llvm/llvm-project/issues/63837.
Despite CWG2497 not being resolved, it is reasonable to expect the
following code to compile (and which is supported by other compilers)
```cpp
template<typename T> constexpr T f();
constexpr int g() { return f<int>(); } // #1
template<typename T> constexpr T f() { return 123; }
int k[g()];
// #2
```
To that end, we eagerly instantiate all referenced specializations of
constexpr functions when they are defined.
We maintain a map of (pattern, [instantiations]) independent of
`PendingInstantiations` to avoid having to iterate that list after each
function definition.
We should apply the same logic to constexpr variables, but I wanted to
keep the PR small.
Fixes#73232
This change implements parsing for HLSL's parameter modifier keywords
`in`, `out` and `inout`. Because HLSL doesn't support references or
pointers, these keywords are used to allow parameters to be passed in
and out of functions.
This change only implements the parsing and AST support. In the HLSL
ASTs we represent `out` and `inout` parameters as references, and we
implement the semantics of by-value passing during IR generation.
In HLSL parameters marked `out` and `inout` are ambiguous in function
declarations, and `in`, `out` and `inout` may be ambiguous at call
sites.
This means a function may be defined as `fn(in T)` and `fn(inout T)` or
`fn(out T)`, but not `fn(inout T)` and `fn(out T)`. If a funciton `fn`
is declared with `in` and `inout` or `out` arguments, the call will be
ambiguous the same as a C++ call would be ambiguous given declarations
`fn(T)` and `fn(T&)`.
Fixes#59849
This change aims to fix
https://github.com/llvm/llvm-project/issues/70375
It appears to me that the logic here should be handling specializations
in general, not just partial specialization. It also seems that both the
comment before the block and the `isInstantiationOf(ClassTemplate,
SpecTemplate)` below agree with my judgement.
The issue might just be a mistake that someone mistaken specialization
as a special case of partial specializations, while it's actually the
other way around.
Needs some experts to comment here if this is the right fix.
The code that caused clang ICE is added as a test case.
Modifications:
- Skip the instantiation of the explicit-specifier during Decl
substitution if we are deducing template arguments and the
explicit-specifier is value dependent.
- Instantiate the explicit-specifier after the constraint checking
completes.
- Make `instantiateExplicitSpecifier` a member function in order to
instantiate the explicit-specifier in different stages.
This PR doesn’t defer the instantiation of the explicit specifier for
deduction guides, because I’m not familiar with deduction guides yet.
I’ll dig into it after this PR.
According to my local test, GCC 13 tuple works with this PR.
Fixes#59827.
---------
Co-authored-by: Erich Keane <ekeane@nvidia.com>
