Closing https://github.com/llvm/llvm-project/issues/56826.
The root cause for pr56826 is: when we collect the template args for the
friend, we need to judge if the friend lives in file context. However,
if the friend lives in ExportDecl lexically, the judgement here is
invalid.
The solution is easy. We should judge the non transparent context and
the ExportDecl is transparent context. So the solution should be good.
A main concern may be the patch doesn't handle all the places of the
same defect. I think it might not be bad since the patch itself should
be innocent.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D131651
Use of `ORIGINAL_PCH_DIR` record has been superseeded by making PCH/PCM files with relocatable paths at write time.
Removing this record is useful for producing an output-path-independent PCH file and enable sharing of the same PCH file even
when it was intended for a different output path.
Differential Revision: https://reviews.llvm.org/D131124
Sharing the FileManager between the importer and the module build should
only be an optimization. Add a cc1 option -fno-modules-share-filemanager
to allow us to test this. Fix the path to modulemap files, which
previously depended on the shared FileManager when using path mapped to
an external file in a VFS.
Differential Revision: https://reviews.llvm.org/D131076
This is successor for D125291. This revision would try to use
@llvm.threadlocal.address in clang to access TLS variable. The reason
why the OpenMP tests contains a lot of change is that they uses
utils/update_cc_test_checks.py to update their tests.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D129833
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 use of preferred_name would block implementing std
modules in libcxx. See https://github.com/llvm/llvm-project/issues/56490
for example.
The problem is pretty hard and it looks like we couldn't solve it in a
short time. So we sent this patch as a workaround to avoid blocking us
to modularize STL. This is intended to be fixed properly in the future.
Reviewed By: erichkeane, aaron.ballman, tahonermann
Differential Revision: https://reviews.llvm.org/D130331
The original implementation uses `ND->getFormalLinkage() <=
Linkage::InternalLinkage`. It is not right since the spec only says
internal linkage and it doesn't mention 'no linkage'. This matters when
we consider constructors. According to [class.ctor.general]p1,
constructors have no name so constructors have no linkage too.
Currently, the semantics of linkage in clang is slightly
different from the semantics in C++ spec. In C++ spec, only names
have linkage. So that all entities of the same should share
one linkage. But in clang, different entities of the same could
have different linkage.
It would break a use case where the template have external linkage and
its specialization have internal linkage due to its type argument is
internal linkage. The root cause is that the semantics of internal
linkage in clang is a mixed form of internal linkage and TU-local in
C++ spec. It is hard to solve the root problem and I tried to add a
workaround inplace.
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
Clang has traditionally allowed C programs to implicitly convert
integers to pointers and pointers to integers, despite it not being
valid to do so except under special circumstances (like converting the
integer 0, which is the null pointer constant, to a pointer). In C89,
this would result in undefined behavior per 3.3.4, and in C99 this rule
was strengthened to be a constraint violation instead. Constraint
violations are most often handled as an error.
This patch changes the warning to default to an error in all C modes
(it is already an error in C++). This gives us better security posture
by calling out potential programmer mistakes in code but still allows
users who need this behavior to use -Wno-error=int-conversion to retain
the warning behavior, or -Wno-int-conversion to silence the diagnostic
entirely.
Differential Revision: https://reviews.llvm.org/D129881
Diagnostic for `-Wauto-import` shouldn't be a warning because it doesn't
represent a potential problem in code that should be fixed. And the
emitted fix-it is likely to trigger `-Watimport-in-framework-header`
which makes it challenging to have a warning-free codebase. But it is
still useful to see how include directives are translated into modular
imports and which module a header belongs to, that's why keep it as a remark.
Keep `-Wauto-import` for now to allow a gradual migration for codebases
using `-Wno-auto-import`, e.g., `-Weverything -Wno-auto-import`.
rdar://79594287
Differential Revision: https://reviews.llvm.org/D130138
Currently, clang may meet an infinite loop in a very tricky case when it
iterates the default args. This patch tries to fix this by adding a
`fixed` check.
Previously, we forget to handle reachability for deduction guide.
The deduction guide is a hint to the compiler. And the deduction guide
should be able to use if the corresponding template decl is reachable.
Following some recent discussions, this changes the representation
of callbrs in IR. The current blockaddress arguments are replaced
with `!` label constraints that refer directly to callbr indirect
destinations:
; Before:
%res = callbr i8* asm "", "=r,r,i"(i8* %x, i8* blockaddress(@test8, %foo))
to label %asm.fallthrough [label %foo]
; After:
%res = callbr i8* asm "", "=r,r,!i"(i8* %x)
to label %asm.fallthrough [label %foo]
The benefit of this is that we can easily update the successors of
a callbr, without having to worry about also updating blockaddress
references. This should allow us to remove some limitations:
* Allow unrolling/peeling/rotation of callbr, or any other
clone-based optimizations
(https://github.com/llvm/llvm-project/issues/41834)
* Allow duplicate successors
(https://github.com/llvm/llvm-project/issues/45248)
This is just the IR representation change though, I will follow up
with patches to remove limtations in various transformation passes
that are no longer needed.
Differential Revision: https://reviews.llvm.org/D129288
This reverts commit 7c51f02effdbd0d5e12bfd26f9c3b2ab5687c93f 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 bdc6974f92304f4ed542241b9b89ba58ba6b20aa 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
There were two assertions in DefaultArgStorage::setInherited previously.
It requires the DefaultArgument is either empty or an argument value. It
would crash if it has a pointer refers to the previous declaration or
contains a chain to the previous declaration.
But there are edge cases could hit them actually. One is
InheritDefaultArguments.cppm that I found recently. Another one is pr31469.cpp,
which was created fives years ago.
This patch tries to fix the two failures by handling full cases in
DefaultArgStorage::setInherited.
This is guaranteed to not introduce any breaking change since it lives
in the path we wouldn't touch before. And the added assertions for
sameness should keep the correctness.
Reviewed By: v.g.vassilev
Differential Revision: https://reviews.llvm.org/D128974
parameters.
The current implementation to judge the similarity of TypeConstraint in
ASTContext::isSameTemplateParameter is problematic, it couldn't handle
the following case:
```C++
template <__integer_like _Tp, C<_Tp> Sentinel>
constexpr _Tp operator()(_Tp &&__t, Sentinel &&last) const {
return __t;
}
```
When we see 2 such declarations from different modules, we would judge
their similarity by `ASTContext::isSame*` methods. But problems come for
the TypeConstraint. Originally, we would profile each argument one by
one. But it is not right. Since the profiling result of `_Tp` would
refer to two different template type declarations. So it would get
different results. It is right since the `_Tp` in different modules
refers to different declarations indeed. So the same declaration in
different modules would meet incorrect our-checking results.
It is not the thing we want. We want to know if the TypeConstraint have
the same expression.
Reviewer: vsapsai, ilya-biryukov
Differential Revision: https://reviews.llvm.org/D129068
This addresses [cpp.include]/7
(when encountering #include header-name)
If the header identified by the header-name denotes an importable header, it
is implementation-defined whether the #include preprocessing directive is
instead replaced by an import directive.
In this implementation, include translation is performed _only_ for headers
in the Global Module fragment, so:
```
module;
#include "will-be-translated.h" // IFF the header unit is available.
export module M;
#include "will-not-be-translated.h" // even if the header unit is available
```
The reasoning is that, in general, includes in the module purview would not
be validly translatable (they would have to immediately follow the module
decl and without any other intervening decls). Otherwise that would violate
the rules on contiguous import directives.
This would be quite complex to track in the preprocessor, and for relatively
little gain (the user can 'import "will-not-be-translated.h";' instead.)
TODO: This is one area where it becomes increasingly difficult to disambiguate
clang modules in C++ from C++ standard modules. That needs to be addressed in
both the driver and the FE.
Differential Revision: https://reviews.llvm.org/D128981
The existing provision is not sufficient, it did not allow for the cases
where an implementation partition includes the primary module interface,
or for the case that an exported interface partition is contains a decl
that is then implemented in a regular implementation unit.
It is somewhat unfortunate that we have to compare top level module names
to achieve this, since built modules are not necessarily available.
TODO: It might be useful to cache a hash of the primary module name if
this test proves to be a significant load.
Differential Revision: https://reviews.llvm.org/D127624
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
When we do profiling in ASTContext::getAutoType, it wouldn't think about
the canonical declaration for the type constraint. It is bad since it
would cause a negative ODR mismatch while we already know the type
constraint declaration is a redeclaration for the previous one. Also it shouldn't be
bad to use the canonical declaration here.
Currently we do not in general merge attributes when importing decls from modules. This patch handles availability, but long term we need to properly handle all attributes.
I tried to use Sema::mergeDeclAttributes, but it caused test crashes as I don't think it expects to be called in this context. We really shouldn't have duplicate code for merging attributes long term, but for now this fixes availability. There's already a TODO for this in the declaration of ASTDeclReader::mergeInheritableAttributes.
Differential Revision: https://reviews.llvm.org/D127182
rdar://85820301
DebugTypeVisitor
This recommits d1346e2. I've added a line to the test case to enable it
only on assert builds.
Differential Revision: https://reviews.llvm.org/D125839
This reverts commit a544710cd43ba9f7729a613c58729f146e792a8e.
See discussion in D120540.
This breaks C++ Clang modules on Darwin and also more than a dozen
tests in the LLDB testsuite. I think we need to be more careful to
separate out the enabling of Clang C++ modules and C++20
modules. Either by having -fmodules-ts control the HaveModules flag,
or by adding a way to explicitly turn them off.
This patch allows user to use C++20 module by -fcxx-modules. Previously,
we could only use it under -std=c++20. Given that user could use C++20
coroutine standalonel by -fcoroutines-ts. It makes sense to offer an
option to use C++20 modules without enabling C++20.
Reviewed By: iains, MaskRay
Differential Revision: https://reviews.llvm.org/D120540
This patch allows user to use C++20 module by -fcxx-modules. Previously,
we could only use it under -std=c++20. Given that user could use C++20
coroutine standalonel by -fcoroutines-ts. It makes sense to offer an
option to use C++20 modules without enabling C++20.
Reviewed By: iains, MaskRay
Differential Revision: https://reviews.llvm.org/D120540
This diff changes the serialization of the `ORIGINAL_PCH_DIR`
entry in module files to be serialized relative to the module's
`BaseDirectory`. This will allow for the module to be relocatable
across machines.
The path is restored relative to the module's BaseDirectory on
deserialization.
Reviewed By: urnathan
Differential Revision: https://reviews.llvm.org/D124946
This diff changes the serialization of the `SUBMODULE_TOPHEADER`
entry in module files to be serialized relative to the module's
`BaseDirectory`. This matches the behavior of the
`SUBMODULE_HEADER` entry and will allow for the module to be
relocatable across machines.
The path is restored relative to the module's `BaseDirectory` on
deserialization.
Reviewed By: urnathan
Differential Revision: https://reviews.llvm.org/D124938
This diff adds a new frontend flag `-fmodule-file-home-is-cwd`.
The behavior of this flag is similar to
`-fmodule-map-file-home-is-cwd` but does not require the module
map files to be modified to have inputs relative to the cwd.
Instead the output modules will have their `BaseDirectory` set
to the cwd and will try and resolve paths relative to that.
The motiviation for this change is to support relocatable pcm
files that are built on different machines with different paths
without having to alter module map files, which is sometimes not
possible as they are provided by 3rd parties.
Reviewed By: urnathan
Differential Revision: https://reviews.llvm.org/D124874
