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 <[email protected]>

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 <[email protected]>

Differential Revision: https://reviews.llvm.org/D112374

show more ...

[clang] Stop providing builtin overload candidate for relational function pointer comparisons

Word on the grapevine was that the committee had some discussion that
ended with unanimous agreement on

[clang] Stop providing builtin overload candidate for relational function pointer comparisons

Word on the grapevine was that the committee had some discussion that
ended with unanimous agreement on eliminating relational function pointer comparisons.

We wanted to be bold and just ban all of them cold turkey.
But then we chickened out at the last second and are going for
eliminating just the spaceship overload candidate instead, for now.

See D104680 for reference.

This should be fine and "safe", because the only possible semantic change this
would cause is that overload resolution could possibly be ambiguous if
there was another viable candidate equally as good.

But to save face a little we are going to:
* Issue an "error" for three-way comparisons on function pointers.
But all this is doing really is changing one vague error message,
from an "invalid operands to binary expression" into an
"ordered comparison of function pointers", which sounds more like we mean business.
* Otherwise "warn" that comparing function pointers like that is totally
not cool (unless we are told to keep quiet about this).

Signed-off-by: Matheus Izvekov <[email protected]>

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D104892

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[Clang] -Wunused-but-set-parameter and -Wunused-but-set-variable

These are intended to mimic warnings available in gcc.

Differential Revision: https://reviews.llvm.org/D100581

Revert "[Clang] -Wunused-but-set-parameter and -Wunused-but-set-variable"

This reverts commit 14dfb3831c425c7f22540a2160424224008c257e.

More false positives, see D100581.

[Clang] -Wunused-but-set-parameter and -Wunused-but-set-variable

These are intended to mimic warnings available in gcc.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D100581

Revert "[Clang] -Wunused-but-set-parameter and -Wunused-but-set-variable"

This reverts commit 9b0501abc7b515b740fb5ee929817442dd3029a5.

False positives reported in D100581.

[Clang] -Wunused-but-set-parameter and -Wunused-but-set-variable

These are intended to mimic warnings available in gcc.

-Wunused-but-set-variable is triggered in the case of a variable which
appear

[Clang] -Wunused-but-set-parameter and -Wunused-but-set-variable

These are intended to mimic warnings available in gcc.

-Wunused-but-set-variable is triggered in the case of a variable which
appears on the LHS of an assignment but not otherwise used.

For instance:

void f() {
int x;
x = 0;
}

-Wunused-but-set-parameter works similarly, but for function parameters
instead of variables.

In C++, they are triggered only for scalar types; otherwise, they are
triggered for all types. This is gcc's behavior.

-Wunused-but-set-parameter is controlled by -Wextra, while
-Wunused-but-set-variable is controlled by -Wunused. This is slightly
different from gcc's behavior, but seems most consistent with clang's
behavior for -Wunused-parameter and -Wunused-variable.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D100581

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PR12350: Handle remaining cases permitted by CWG DR 244.

Also add extension warnings for the cases that are disallowed by the
current rules for destructor name lookup, refactor and simplify the
look

PR12350: Handle remaining cases permitted by CWG DR 244.

Also add extension warnings for the cases that are disallowed by the
current rules for destructor name lookup, refactor and simplify the
lookup code, and improve the diagnostic quality when lookup fails.

The special case we previously supported for converting
p->N::S<int>::~S() from naming a class template into naming a
specialization thereof is subsumed by a more general rule here (which is
also consistent with Clang's historical behavior and that of other
compilers): if we can't find a suitable S in N, also look in N::S<int>.

The extension warnings are off by default, except for a warning when
lookup for p->N::S::~T() looks for T in scope instead of in N (or N::S).
That seems sufficiently heinous to warn on by default, especially since
we can't support it for a dependent nested-name-specifier.

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Replace remaining user-visible mentions of C++1z with C++17.

llvm-svn: 310804

[Sema] Improve the error diagnostic for dot destructor calls on pointer objects

This commit improves the mismatched destructor type error by detecting when the
destructor call has used a '.' instead

[Sema] Improve the error diagnostic for dot destructor calls on pointer objects

This commit improves the mismatched destructor type error by detecting when the
destructor call has used a '.' instead of a '->' on a pointer to the destructed
type. The diagnostic now suggests to use '->' instead of '.', and adds a fixit
where appropriate.

rdar://28766702

Differential Revision: https://reviews.llvm.org/D25817

llvm-svn: 292615

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Make some diagnostic tests C++11 clean.

Differential Revision: http://reviews.llvm.org/D27794

llvm-svn: 290262

Undo accidental comit

llvm-svn: 290121

Make a few OpenMP tests "C++11 clean."

Reviewed by abataev (in D27794)

llvm-svn: 290120

Promote a warning on ill-formed code (redeclaration missing an exception
specification) to an error. No compiler other than Clang seems to allow this,
and it doesn't seem like a useful thing to accep

Promote a warning on ill-formed code (redeclaration missing an exception
specification) to an error. No compiler other than Clang seems to allow this,
and it doesn't seem like a useful thing to accept as an extension in general.

The current behavior was added for PR5957, where the problem was specifically
related to mismatches of the exception specification on the implicitly-declared
global operator new and delete. To retain that workaround, we downgrade the
error to an ExtWarn when the declaration is of a replaceable global allocation
function.

Now that this is an error, stop trying (and failing) to recover from a missing
computed noexcept specification. That recovery didn't work, and led to crashes
in code like the added testcase.

llvm-svn: 248867

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Move fixit for const init from note to diag, weaken to warning in MS mode.

r235046 turned "extern __declspec(selectany) int a;" from a declaration into
a definition to fix PR23242 (required for comp

Move fixit for const init from note to diag, weaken to warning in MS mode.

r235046 turned "extern __declspec(selectany) int a;" from a declaration into
a definition to fix PR23242 (required for compatibility with mc.exe output).
However, this broke parsing Windows headers: A d3d11 headers contain something
like

struct SomeStruct {};
extern const __declspec(selectany) SomeStruct some_struct;

This is now a definition, and const objects either need an explicit default
ctor or an initializer so this errors out with

d3d11.h(1065,48) :
error: default initialization of an object of const type
'const CD3D11_DEFAULT' without a user-provided default constructor

(cl.exe just doesn't implement this rule, independent of selectany.)

To work around this, weaken this error into a warning for selectany decls
in microsoft mode, and recover with zero-initialization.

Doing this is a bit hairy since it adds a fixit on an error emitted
by InitializationSequence – this means it needs to build a correct AST, which
in turn means InitializationSequence::Failed() cannot return true when this
fixit is applied. As a workaround, the patch adds a fixit member to
InitializationSequence, and InitializationSequence::Perform() prints the
diagnostic if the fixit member is set right after its call to Diagnose.
That function is usually called when InitializationSequences are used –
InitListChecker::PerformEmptyInit() doesn't call it, but the InitListChecker
case never performs default-initialization, so this is technically OK.

This is the alternative, original fix for PR20208 that got reviewed in the
thread "[patch] Improve diagnostic on default-initializing const variables
(PR20208)". This change basically reverts r213725, adds the original fix for
PR20208, and makes the error a warning in Microsoft mode.

llvm-svn: 235166

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Unify warnings/errors from "maybe you meant" to "did you mean".

llvm-svn: 233981

PR21969: Improve diagnostics for a conversion function that has any pieces of a
declared return type (including a trailing-return-type in C++14).

llvm-svn: 224561

Suggest fix-it for missing '{' after base-clause

llvm-svn: 218468

Add error, recovery and fixit for "~A::A() {...}".

llvm-svn: 217302

[C++1z] Implement N4051: 'typename' is permitted instead of 'class' when declaring a template template parameter.

llvm-svn: 211031

Refactor all the checking for missing 'template<>'s when a declaration has a
template-id after its scope specifier into a single place.

llvm-svn: 206442

A few small cleanups to r187504. Thanks to dblaikie for the assist.

llvm-svn: 187521