[clang] Fix covariant cv-qualification check to require the override function return type to have the same or less cv-qualification (#112713)

This prevents changing cv-qualification from const to vo

[clang] Fix covariant cv-qualification check to require the override function return type to have the same or less cv-qualification (#112713)

This prevents changing cv-qualification from const to volatile or vice
versa, for example.

https://eel.is/c++draft/class.virtual#8.3

Previously, we checked that the new type is the same or more qualified
to return an error, but the standard requires the new type to be the
same or less qualified and since the cv-qualification is only partially
ordered, we cannot rely on a check on whether it is more qualified to
return an error. Now, we reversed the condition to check whether the old
is at least as qualified, and return an error if it is not.

Also, adjusted the error name and message to clarify the requirement and
added a missing closing parenthesis.

Added tests to cover different use cases for classes with different
qualifications and also refactored them to make them easier to follow:
1. Use override to make sure the function names actually match.
2. Named the function in a more descriptive way to clarify what each use
case is checking.

Fixes: #111742

show more ...

[clang] When checking for covariant return types, make sure the pointers or references are to *classes* (#111856)

https://eel.is/c++draft/class.virtual#8.1

This prevents overriding methods with n

[clang] When checking for covariant return types, make sure the pointers or references are to *classes* (#111856)

https://eel.is/c++draft/class.virtual#8.1

This prevents overriding methods with non class return types that have
less cv-qualification.

Fixes: #111742

show more ...

[clang] Implement ElaboratedType sugaring for types written bare

Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which go

[clang] Implement ElaboratedType sugaring for types written bare

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

show more ...

Revert "[clang] Implement ElaboratedType sugaring for types written bare"

This reverts commit 7c51f02effdbd0d5e12bfd26f9c3b2ab5687c93f because it
stills breaks the LLDB tests. This was re-landed wi

Revert "[clang] Implement ElaboratedType sugaring for types written bare"

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.

show more ...

[clang] Implement ElaboratedType sugaring for types written bare

Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which go

[clang] Implement ElaboratedType sugaring for types written bare

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

show more ...

Revert "[clang] Implement ElaboratedType sugaring for types written bare"

This reverts commit bdc6974f92304f4ed542241b9b89ba58ba6b20aa because it
breaks all the LLDB tests that import the std module

Revert "[clang] Implement ElaboratedType sugaring for types written bare"

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/

show more ...

[clang] Implement ElaboratedType sugaring for types written bare

Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which go

[clang] Implement ElaboratedType sugaring for types written bare

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

show more ...

Mark DR1250 as implemented

We implemented this DR back in r258768 but forgot to mark it as
implemented.

llvm-svn: 259335

[Sema] Incomplete types are OK for covariant returns

Per C++14 [class.virtual]p8, it is OK for the return type's class type
to be incomplete so long as the return type is the same between the base
a

[Sema] Incomplete types are OK for covariant returns

Per C++14 [class.virtual]p8, it is OK for the return type's class type
to be incomplete so long as the return type is the same between the base
and complete classes.

This fixes PR26297.

llvm-svn: 258768

show more ...

PR6037
Warn on inaccessible direct base

llvm-svn: 226423

Remove the -cxx-abi command-line flag.

This makes the C++ ABI depend entirely on the target: MS ABI for -win32 triples,
Itanium otherwise. It's no longer possible to do weird combinations.

To be ab

Remove the -cxx-abi command-line flag.

This makes the C++ ABI depend entirely on the target: MS ABI for -win32 triples,
Itanium otherwise. It's no longer possible to do weird combinations.

To be able to run a test with a specific ABI without constraining it to a
specific triple, new substitutions are added to lit: %itanium_abi_triple and
%ms_abi_triple can be used to get the current target triple adjusted to the
desired ABI. For example, if the test suite is running with the i686-pc-win32
target, %itanium_abi_triple will expand to i686-pc-mingw32.

Differential Revision: http://llvm-reviews.chandlerc.com/D2545

llvm-svn: 199250

show more ...

Better diagnostic for static override when methods are thiscall by default

Methods are thiscall by default in the MS ABI, and also in MinGW targetting GCC 4.7 or later.

This changes the diagnostic

Better diagnostic for static override when methods are thiscall by default

Methods are thiscall by default in the MS ABI, and also in MinGW targetting GCC 4.7 or later.

This changes the diagnostic from the technically correct but hard to understand:

virtual function 'foo' has different calling convention attributes ('void ()') than the function it overrides (which has calling convention 'void () __attribute__((thiscall))')

to the more intuitive and also correct:

'static' member function 'foo' overrides a virtual function

We already have a test for this. Let's just run it in both ABI modes.

Differential Revision: http://llvm-reviews.chandlerc.com/D2375

llvm-svn: 197055

show more ...

Update all tests other than Driver/std.cpp to use -std=c++11 rather than
-std=c++0x. Patch by Ahmed Charles!

llvm-svn: 141900

Fix PR8767, improve diagnostic wording when allocating an object of an
abstract class type.

Patch by Stephen Hines, with a wording tweak from Doug applied by me.

llvm-svn: 125996

When parsing an out-of-line member function declaration, we must delay
access-control diagnostics which arise from the portion of the declarator
following the scope specifier, just in case access is

When parsing an out-of-line member function declaration, we must delay
access-control diagnostics which arise from the portion of the declarator
following the scope specifier, just in case access is granted by
friending the individual method. This can also happen with in-line
member function declarations of class templates due to templated-scope
friend declarations.

We were really playing fast-and-loose before with this sort of thing,
and it turned out to work because *most* friend functions are in file
scope. Making us delay regardless of context exposed several bugs with
how we were manipulating delay. I ended up needing a concept of a
context that's independent of the declarations in which it appears,
and then I actually had to make some things save contexts correctly,
but delay should be much cleaner now.

I also encapsulated all the delayed-diagnostics machinery in a single
subobject of Sema; this is a pattern we might want to consider rolling
out to other components of Sema.

llvm-svn: 125485

show more ...

Enhance the diagnostic for negative array sizes to include the
declaration name of the array when present. This ensures that
a poor-man's C++03 static_assert will include the user error message
often

Enhance the diagnostic for negative array sizes to include the
declaration name of the array when present. This ensures that
a poor-man's C++03 static_assert will include the user error message
often embedded in the name.

Update all the tests to reflect the new wording, and add a test for the
name behavior.

llvm-svn: 122802

show more ...

Diagnose when a 'static' member function overrides a virtual function
in a base class. Fixes PR8168.

llvm-svn: 116448

'const std::type_info*' instead of 'std::type_info const*'

llvm-svn: 113092

Turn access control on by default in -cc1.
Remove -faccess-control from -cc1; add -fno-access-control.
Make the driver pass -fno-access-control by default.
Update a bunch of tests to be correct under

Turn access control on by default in -cc1.
Remove -faccess-control from -cc1; add -fno-access-control.
Make the driver pass -fno-access-control by default.
Update a bunch of tests to be correct under access control.

llvm-svn: 100880

show more ...

When pretty-printing tag types, only print the tag if we're in C (and
therefore not creating ElaboratedTypes, which are still pretty-printed
with the written tag).

Most of these testcase changes wer

When pretty-printing tag types, only print the tag if we're in C (and
therefore not creating ElaboratedTypes, which are still pretty-printed
with the written tag).

Most of these testcase changes were done by script, so don't feel too
sorry for my fingers.

llvm-svn: 98149

show more ...

Defer covariance checks for dependent types. Add test cases that also ensure
they are re-checked on instantiation.

llvm-svn: 96217

Improve access control diagnostics. Perform access control on member-pointer
conversions. Fix an access-control bug where privileges were not considered
at intermediate points along the inheritance

Improve access control diagnostics. Perform access control on member-pointer
conversions. Fix an access-control bug where privileges were not considered
at intermediate points along the inheritance path. Prepare for friends.

llvm-svn: 95775

show more ...

No need to canonicalize the type and use dyn_cast. Also, correctly diagnose trying to override a function returning an lvalue reference with a function overriding an rvalue reference.

llvm-svn: 94183

Fix an obvious goof that caused us to only see the top level of return types
when checking for covariance. Added some fun test cases, fixes PR6110.

This felt obvious enough to just commit. ;] Let me

Fix an obvious goof that caused us to only see the top level of return types
when checking for covariance. Added some fun test cases, fixes PR6110.

This felt obvious enough to just commit. ;] Let me know if anything needs
tweaking.

llvm-svn: 94173

show more ...

Make sure that an overriding return type is complete before checking if it's covariant. Fixes PR5920.

llvm-svn: 92365