This implements WG14 N2927 and WG14 N2930, which together define the
feature for typeof and typeof_unqual, which get the type of their
argument as either fully qualified or fully unqualified. The argument
to either operator is either a type name or an expression. If given a
type name, the type information is pulled directly from the given name.
If given an expression, the type information is pulled from the
expression. Recursive use of these operators is allowed and has the
expected behavior (the innermost operator is resolved to a type, and
that's used to resolve the next layer of typeof specifier, until a
fully resolved type is determined.
Note, we already supported typeof in GNU mode as a non-conforming
extension and we are *not* exposing typeof_unqual as a non-conforming
extension in that mode, nor are we exposing typeof or typeof_unqual as
a nonconforming extension in other language modes. The GNU variant of
typeof supports a form where the parentheses are elided from the
operator when given an expression (e.g., typeof 0 i = 12;). When in C2x
mode, we do not support this extension.
Differential Revision: https://reviews.llvm.org/D134286
This patch implements P0634r3 that removes the need for 'typename' in certain contexts.
For example,
```
template <typename T>
using foo = T::type; // ok
```
This is also allowed in previous language versions as an extension, because I think it's pretty useful. :)
Reviewed By: #clang-language-wg, erichkeane
Differential Revision: https://reviews.llvm.org/D53847
Apparently TransformDecl in TreeTransform can be called with a nullptr
for a Decl, so my casts were illegal. The fix here is to add an early
exit to my TransformDecl.
This reverts commit 95d94a6775.
This implements the deferred concepts instantiation, which should allow
the libstdc++ ranges to properly compile, and for the CRTP to work for
constrained functions.
Since the last attempt, this has fixed the issues from @wlei and
@mordante.
Differential Revision: https://reviews.llvm.org/D126907
This change allows us to represent in the AST some specific
circumstances where we substitute a template parameter type
which is part of the underlying type of a previous substitution.
This presently happens in some circumstances dealing with
substitution of defaulted parameters of template template
parameters, and in some other cases during concepts substitution.
The main motivation for this change is for the future use in the
implementation of template specialization resugaring, as this will
allow us to represent a substitution with sugared types.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D132816
Implement suggested fix for [[ https://cplusplus.github.io/CWG/issues/2628.html | DR2628. ]] Couldn't update the DR docs because there hasn't been a DR index since it was filed, but the tests still run in CI.
Note: I only transfer the constructor constraints, not the struct constraints. I think that's OK because the struct constraints are the same
for all constructors so they don't affect the overload resolution, and if they deduce to something that doesn't pass the constraints
we catch it anyway. So (hopefully) that should be more efficient without sacrificing correctness.
Closes:
https://github.com/llvm/llvm-project/issues/57646https://github.com/llvm/llvm-project/issues/43829
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D134145
It is possible that we can pass a null ParamType to
CheckNonTypeTemplateParameter -- the ParamType var can be reset to a null
type on Line 6940, and the followed bailout if is not entered.
Differential Revision: https://reviews.llvm.org/D134180
We change the template specialization of builtin templates to
behave like aliases.
Though unlike real alias templates, these might still produce a canonical
TemplateSpecializationType when some important argument is dependent.
For example, we can't do anything about make_integer_seq when the
count is dependent, or a type_pack_element when the index is dependent.
We change type deduction to not try to deduce canonical TSTs of
builtin templates.
We also change those buitin templates to produce substitution sugar,
just like a real instantiation would, making the resulting type correctly
represent the template arguments used to specialize the underlying template.
And make_integer_seq will now produce a TST for the specialization
of it's first argument, which we use as the underlying type of
the builtin alias.
When performing member access on the resulting type, it's now
possible to map from a Subst* node to the template argument
as-written used in a regular fashion, without special casing.
And this fixes a bunch of bugs with relation to these builtin
templates factoring into deduction.
Fixes GH42102 and GH51928.
Depends on D133261
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D133262
This continues D111283 by extending the getCommonSugaredType
implementation to also merge non-canonical type nodes.
We merge these nodes by going up starting from the canonical
node, calculating their merged properties on the way.
If we reach a pair that is too different, or which we could not
otherwise unify, we bail out and don't try to keep going on to
the next pair, in effect striping out all the remaining top-level
sugar nodes. This avoids mismatching 'companion' nodes, such as
ElaboratedType, so that they don't end up elaborating some other
unrelated thing.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D130308
After upgrading the type deduction machinery to retain type sugar in
D110216, we were left with a situation where there is no general
well behaved mechanism in Clang to unify the type sugar of multiple
deductions of the same type parameter.
So we ended up making an arbitrary choice: keep the sugar of the first
deduction, ignore subsequent ones.
In general, we already had this problem, but in a smaller scale.
The result of the conditional operator and many other binary ops
could benefit from such a mechanism.
This patch implements such a type sugar unification mechanism.
The basics:
This patch introduces a `getCommonSugaredType(QualType X, QualType Y)`
method to ASTContext which implements this functionality, and uses it
for unifying the results of type deduction and return type deduction.
This will return the most derived type sugar which occurs in both X and
Y.
Example:
Suppose we have these types:
```
using Animal = int;
using Cat = Animal;
using Dog = Animal;
using Tom = Cat;
using Spike = Dog;
using Tyke = Dog;
```
For `X = Tom, Y = Spike`, this will result in `Animal`.
For `X = Spike, Y = Tyke`, this will result in `Dog`.
How it works:
We take two types, X and Y, which we wish to unify as input.
These types must have the same (qualified or unqualified) canonical
type.
We dive down fast through top-level type sugar nodes, to the
underlying canonical node. If these canonical nodes differ, we
build a common one out of the two, unifying any sugar they had.
Note that this might involve a recursive call to unify any children
of those. We then return that canonical node, handling any qualifiers.
If they don't differ, we walk up the list of sugar type nodes we dived
through, finding the last identical pair, and returning that as the
result, again handling qualifiers.
Note that this patch will not unify sugar nodes if they are not
identical already. We will simply strip off top-level sugar nodes that
differ between X and Y. This sugar node unification will instead be
implemented in a subsequent patch.
This patch also implements a few users of this mechanism:
* Template argument deduction.
* Auto deduction, for functions returning auto / decltype(auto), with
special handling for initializer_list as well.
Further users will be implemented in a subsequent patch.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D111283
This reverts commit d200db3863, which causes a
clang crash. See https://reviews.llvm.org/D111283#3785755
Test case for convenience:
```
template <typename T>
using P = int T::*;
template <typename T, typename... A>
void j(P<T>, T, A...);
template <typename T>
void j(P<T>, T);
struct S {
int b;
};
void g(P<S> k, S s) { j(k, s); }
```
After upgrading the type deduction machinery to retain type sugar in
D110216, we were left with a situation where there is no general
well behaved mechanism in Clang to unify the type sugar of multiple
deductions of the same type parameter.
So we ended up making an arbitrary choice: keep the sugar of the first
deduction, ignore subsequent ones.
In general, we already had this problem, but in a smaller scale.
The result of the conditional operator and many other binary ops
could benefit from such a mechanism.
This patch implements such a type sugar unification mechanism.
The basics:
This patch introduces a `getCommonSugaredType(QualType X, QualType Y)`
method to ASTContext which implements this functionality, and uses it
for unifying the results of type deduction and return type deduction.
This will return the most derived type sugar which occurs in both X and
Y.
Example:
Suppose we have these types:
```
using Animal = int;
using Cat = Animal;
using Dog = Animal;
using Tom = Cat;
using Spike = Dog;
using Tyke = Dog;
```
For `X = Tom, Y = Spike`, this will result in `Animal`.
For `X = Spike, Y = Tyke`, this will result in `Dog`.
How it works:
We take two types, X and Y, which we wish to unify as input.
These types must have the same (qualified or unqualified) canonical
type.
We dive down fast through top-level type sugar nodes, to the
underlying canonical node. If these canonical nodes differ, we
build a common one out of the two, unifying any sugar they had.
Note that this might involve a recursive call to unify any children
of those. We then return that canonical node, handling any qualifiers.
If they don't differ, we walk up the list of sugar type nodes we dived
through, finding the last identical pair, and returning that as the
result, again handling qualifiers.
Note that this patch will not unify sugar nodes if they are not
identical already. We will simply strip off top-level sugar nodes that
differ between X and Y. This sugar node unification will instead be
implemented in a subsequent patch.
This patch also implements a few users of this mechanism:
* Template argument deduction.
* Auto deduction, for functions returning auto / decltype(auto), with
special handling for initializer_list as well.
Further users will be implemented in a subsequent patch.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D111283
Template arguments of template and declaration kind were being profiled
only by their canonical properties, which would cause incorrect
uniquing of constrained AutoTypes, leading to a crash in some cases.
This exposed some places in CheckTemplateArgumentList where non-canonical
arguments where being pushed into the resulting converted list.
We also throw in some asserts to catch early and explain the crashes.
Note that the fix for the 'declaration' kind is untestable at this point,
because there should be no cases right now in the AST where we try
to unique a non-canonical converted template argument.
This fixes GH55567.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D133072
In Sema::LookupTemplateName(...) seeks to assert that the ObjectType is complete
or being defined. If the type is incomplete it will attempt to unconditionally
cast it to a TagType and not all incomplete types are a TagType. For example the
type could be void or it could be an IncompleteArray.
This change adds an additional check to confirm it is a TagType before attempting
to check if it is incomplete or being defined
Differential Revision: https://reviews.llvm.org/D132712
This reverts commit d483730d8c.
This allegedly breaks a significant part of facebooks internal build.
Reverting while we wait for them to provide a reproducer of this from
@wlei.
This reverts commit 258c3aee54.
This should fix the libc++ issue that caused the revert, by re-designing
slightly how we determined when we should evaluate the constraints.
Additionally, many of the other components to the original patch (the
NFC parts) were committed separately to shrink the size of this patch
for review.
Differential Revision: https://reviews.llvm.org/D126907
Consider:
A == 5 && A != 5
IfA is 5, the old collectConjunctionTerms() would call itself again for
the LHS (which it ignores), then the RHS (which it also ignores) and
then just return without ever adding anything to the Terms array.
Differential Revision: https://reviews.llvm.org/D131070
In preperation of the deferred instantation progress, this patch
propagates the multi-level template argument lists further through the
API to reduce the size of that patch.
According to [basic.def.odr]p14, the same redeclarations in different TU
but not attached to a named module are allowed. But we didn't take care
of concept decl for this condition. This patch tries to fix this
problem.
Reviewed By: ilya-biryukov
Differention Revision: https://reviews.llvm.org/D130614
Otherwise we get invalid results for ODR checks. See changed test for an
example: despite the fact that we merge the first concept, its **uses**
were considered different by `Profile`, leading to redefinition errors.
After this change, canonical decl for a concept can come from a
different module and may not be visible. This behavior looks suspicious,
but does not break any tests. We might want to add a mechanism to make
the canonical concept declaration visible if we find code that relies on
this invariant.
Additionally make sure we always merge with the canonical declaration to
avoid chains of merged concepts being reported as redefinitions. An
example was added to the test.
Also change the order of includes in the test. Importing a moduralized
header before its textual part causes the include guard macro to be
exported and the corresponding `#include` becomes a no-op.
Reviewed By: ChuanqiXu
Differential Revision: https://reviews.llvm.org/D130585
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.
The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.
An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.
---
Troubleshooting list to deal with any breakage seen with this patch:
1) The most likely effect one would see by this patch is a change in how
a type is printed. The type printer will, by design and default,
print types as written. There are customization options there, but
not that many, and they mainly apply to how to print a type that we
somehow failed to track how it was written. This patch fixes a
problem where we failed to distinguish between a type
that was written without any elaborated-type qualifiers,
such as a 'struct'/'class' tags and name spacifiers such as 'std::',
and one that has been stripped of any 'metadata' that identifies such,
the so called canonical types.
Example:
```
namespace foo {
struct A {};
A a;
};
```
If one were to print the type of `foo::a`, prior to this patch, this
would result in `foo::A`. This is how the type printer would have,
by default, printed the canonical type of A as well.
As soon as you add any name qualifiers to A, the type printer would
suddenly start accurately printing the type as written. This patch
will make it print it accurately even when written without
qualifiers, so we will just print `A` for the initial example, as
the user did not really write that `foo::` namespace qualifier.
2) This patch could expose a bug in some AST matcher. Matching types
is harder to get right when there is sugar involved. For example,
if you want to match a type against being a pointer to some type A,
then you have to account for getting a type that is sugar for a
pointer to A, or being a pointer to sugar to A, or both! Usually
you would get the second part wrong, and this would work for a
very simple test where you don't use any name qualifiers, but
you would discover is broken when you do. The usual fix is to
either use the matcher which strips sugar, which is annoying
to use as for example if you match an N level pointer, you have
to put N+1 such matchers in there, beginning to end and between
all those levels. But in a lot of cases, if the property you want
to match is present in the canonical type, it's easier and faster
to just match on that... This goes with what is said in 1), if
you want to match against the name of a type, and you want
the name string to be something stable, perhaps matching on
the name of the canonical type is the better choice.
3) This patch could expose a bug in how you get the source range of some
TypeLoc. For some reason, a lot of code is using getLocalSourceRange(),
which only looks at the given TypeLoc node. This patch introduces a new,
and more common TypeLoc node which contains no source locations on itself.
This is not an inovation here, and some other, more rare TypeLoc nodes could
also have this property, but if you use getLocalSourceRange on them, it's not
going to return any valid locations, because it doesn't have any. The right fix
here is to always use getSourceRange() or getBeginLoc/getEndLoc which will dive
into the inner TypeLoc to get the source range if it doesn't find it on the
top level one. You can use getLocalSourceRange if you are really into
micro-optimizations and you have some outside knowledge that the TypeLocs you are
dealing with will always include some source location.
4) Exposed a bug somewhere in the use of the normal clang type class API, where you
have some type, you want to see if that type is some particular kind, you try a
`dyn_cast` such as `dyn_cast<TypedefType>` and that fails because now you have an
ElaboratedType which has a TypeDefType inside of it, which is what you wanted to match.
Again, like 2), this would usually have been tested poorly with some simple tests with
no qualifications, and would have been broken had there been any other kind of type sugar,
be it an ElaboratedType or a TemplateSpecializationType or a SubstTemplateParmType.
The usual fix here is to use `getAs` instead of `dyn_cast`, which will look deeper
into the type. Or use `getAsAdjusted` when dealing with TypeLocs.
For some reason the API is inconsistent there and on TypeLocs getAs behaves like a dyn_cast.
5) It could be a bug in this patch perhaps.
Let me know if you need any help!
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D112374
Currently the C++20 concepts are only merged in `ASTReader`, i.e. when
coming from different TU. This can causes ambiguious reference errors when
trying to access the same concept that should otherwise be merged.
Please see the added test for an example.
Note that we currently use `ASTContext::isSameEntity` to check for ODR
violations. However, it will not check that concept requirements match.
The same issue holds for mering concepts from different TUs, I added a
FIXME and filed a GH issue to track this:
https://github.com/llvm/llvm-project/issues/56310
Reviewed By: ChuanqiXu
Differential Revision: https://reviews.llvm.org/D128921
This reverts commit 7c51f02eff because it
stills breaks the LLDB tests. This was re-landed without addressing the
issue or even agreement on how to address the issue. More details and
discussion in https://reviews.llvm.org/D112374.
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.
The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.
An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.
---
Troubleshooting list to deal with any breakage seen with this patch:
1) The most likely effect one would see by this patch is a change in how
a type is printed. The type printer will, by design and default,
print types as written. There are customization options there, but
not that many, and they mainly apply to how to print a type that we
somehow failed to track how it was written. This patch fixes a
problem where we failed to distinguish between a type
that was written without any elaborated-type qualifiers,
such as a 'struct'/'class' tags and name spacifiers such as 'std::',
and one that has been stripped of any 'metadata' that identifies such,
the so called canonical types.
Example:
```
namespace foo {
struct A {};
A a;
};
```
If one were to print the type of `foo::a`, prior to this patch, this
would result in `foo::A`. This is how the type printer would have,
by default, printed the canonical type of A as well.
As soon as you add any name qualifiers to A, the type printer would
suddenly start accurately printing the type as written. This patch
will make it print it accurately even when written without
qualifiers, so we will just print `A` for the initial example, as
the user did not really write that `foo::` namespace qualifier.
2) This patch could expose a bug in some AST matcher. Matching types
is harder to get right when there is sugar involved. For example,
if you want to match a type against being a pointer to some type A,
then you have to account for getting a type that is sugar for a
pointer to A, or being a pointer to sugar to A, or both! Usually
you would get the second part wrong, and this would work for a
very simple test where you don't use any name qualifiers, but
you would discover is broken when you do. The usual fix is to
either use the matcher which strips sugar, which is annoying
to use as for example if you match an N level pointer, you have
to put N+1 such matchers in there, beginning to end and between
all those levels. But in a lot of cases, if the property you want
to match is present in the canonical type, it's easier and faster
to just match on that... This goes with what is said in 1), if
you want to match against the name of a type, and you want
the name string to be something stable, perhaps matching on
the name of the canonical type is the better choice.
3) This patch could exposed a bug in how you get the source range of some
TypeLoc. For some reason, a lot of code is using getLocalSourceRange(),
which only looks at the given TypeLoc node. This patch introduces a new,
and more common TypeLoc node which contains no source locations on itself.
This is not an inovation here, and some other, more rare TypeLoc nodes could
also have this property, but if you use getLocalSourceRange on them, it's not
going to return any valid locations, because it doesn't have any. The right fix
here is to always use getSourceRange() or getBeginLoc/getEndLoc which will dive
into the inner TypeLoc to get the source range if it doesn't find it on the
top level one. You can use getLocalSourceRange if you are really into
micro-optimizations and you have some outside knowledge that the TypeLocs you are
dealing with will always include some source location.
4) Exposed a bug somewhere in the use of the normal clang type class API, where you
have some type, you want to see if that type is some particular kind, you try a
`dyn_cast` such as `dyn_cast<TypedefType>` and that fails because now you have an
ElaboratedType which has a TypeDefType inside of it, which is what you wanted to match.
Again, like 2), this would usually have been tested poorly with some simple tests with
no qualifications, and would have been broken had there been any other kind of type sugar,
be it an ElaboratedType or a TemplateSpecializationType or a SubstTemplateParmType.
The usual fix here is to use `getAs` instead of `dyn_cast`, which will look deeper
into the type. Or use `getAsAdjusted` when dealing with TypeLocs.
For some reason the API is inconsistent there and on TypeLocs getAs behaves like a dyn_cast.
5) It could be a bug in this patch perhaps.
Let me know if you need any help!
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D112374
This reverts commit bdc6974f92 because it
breaks all the LLDB tests that import the std module.
import-std-module/array.TestArrayFromStdModule.py
import-std-module/deque-basic.TestDequeFromStdModule.py
import-std-module/deque-dbg-info-content.TestDbgInfoContentDequeFromStdModule.py
import-std-module/forward_list.TestForwardListFromStdModule.py
import-std-module/forward_list-dbg-info-content.TestDbgInfoContentForwardListFromStdModule.py
import-std-module/list.TestListFromStdModule.py
import-std-module/list-dbg-info-content.TestDbgInfoContentListFromStdModule.py
import-std-module/queue.TestQueueFromStdModule.py
import-std-module/stack.TestStackFromStdModule.py
import-std-module/vector.TestVectorFromStdModule.py
import-std-module/vector-bool.TestVectorBoolFromStdModule.py
import-std-module/vector-dbg-info-content.TestDbgInfoContentVectorFromStdModule.py
import-std-module/vector-of-vectors.TestVectorOfVectorsFromStdModule.py
https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/45301/
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.
The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.
An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D112374
See https://github.com/cplusplus/draft/pull/5204 for a detailed
background.
Simply, the test redundant-template-default-arg.cpp attached to this
patch should be accepted instead of being complained about the
redefinition.
Reviewed By: urnathan, rsmith, ChuanqiXu
Differential Revision: https://reviews.llvm.org/D118034
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.
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.
This includes a fix for the libc++ issue I ran across with friend
declarations not properly being identified as overloads.
This reverts commit 45c07db31c.
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.
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.
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.
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
This is the template version of https://reviews.llvm.org/D114251.
This patch introduces a new template name kind (UsingTemplateName). The
UsingTemplateName stores the found using-shadow decl (and underlying
template can be retrieved from the using-shadow decl). With the new
template name, we can be able to find the using decl that a template
typeloc (e.g. TemplateSpecializationTypeLoc) found its underlying template,
which is useful for tooling use cases (include cleaner etc).
This patch merely focuses on adding the node to the AST.
Next steps:
- support using-decl in qualified template name;
- update the clangd and other tools to use this new node;
- add ast matchers for matching different kinds of template names;
Differential Revision: https://reviews.llvm.org/D123127
Aaron Ballman