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 ...

Fix a few tests that were missing ':' on CHECK lines and weren't testing anything.

Found by `git grep '\/\/ CHECK-[^: ]* ' clang/test/ | grep -v RUN:`.

Also tweak CodeGenCXX/arm-swiftcall.cpp to st

Fix a few tests that were missing ':' on CHECK lines and weren't testing anything.

Found by `git grep '\/\/ CHECK-[^: ]* ' clang/test/ | grep -v RUN:`.

Also tweak CodeGenCXX/arm-swiftcall.cpp to still pass now that it checks more.

Differential Revision: https://reviews.llvm.org/D58061

llvm-svn: 353744

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Make two vtable tests tolerate C++11.

In C++11 we don't emit vtables as eagerly as we do for C++03, so
fiddle the tests to emit them when the test expects them.

Differential Revision: http://review

Make two vtable tests tolerate C++11.

In C++11 we don't emit vtables as eagerly as we do for C++03, so
fiddle the tests to emit them when the test expects them.

Differential Revision: http://reviews.llvm.org/D27994

llvm-svn: 290205

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Make -fdump-vtable-layouts print to stdout, not stderr

This makes it consistent with -fdump-record-layouts, which was moved to
outs() in r186219. My reasoning for going with stdout is that when one

Make -fdump-vtable-layouts print to stdout, not stderr

This makes it consistent with -fdump-record-layouts, which was moved to
outs() in r186219. My reasoning for going with stdout is that when one
of these options is present, the layouts are really a program output,
and shouldn't be interleaved with diagnostics, which are on stderr.

Reviewers: timurrrr

Differential Revision: http://llvm-reviews.chandlerc.com/D2127

llvm-svn: 194279

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... and actually run it

llvm-svn: 183309

Add a test for the breakage from r183298

llvm-svn: 183308

Unrevert the tests from r183298 as they pass with both old and new code

llvm-svn: 183306

Revert r183298 and r183300 as the former broke the virtual function lookup in libcxx __locale

llvm-svn: 183305

Get rid of VTableContext::ComputeMethodVTableIndices() and VTableContext::getNumVirtualFunctionPointers(); also add some tests for the VTable indices output to make sure we don't regress

llvm-svn: 1

Get rid of VTableContext::ComputeMethodVTableIndices() and VTableContext::getNumVirtualFunctionPointers(); also add some tests for the VTable indices output to make sure we don't regress

llvm-svn: 183298

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Note deleted functions when dumping vtables.

llvm-svn: 166056

For the annals of subtle but terrible bugs: fix a longstanding bug
in vtable layout where virtual methods inherited from virtual bases
could be assigned the same vcall adjustment slot if they shared

For the annals of subtle but terrible bugs: fix a longstanding bug
in vtable layout where virtual methods inherited from virtual bases
could be assigned the same vcall adjustment slot if they shared
a name and parameter signature but differed in their
cv-qualification. The code was already trying to handle this
case, but unfortunately used the ordinary type qualifiers
(which are always empty here) instead of the method qualifiers.
This seems like something that the API should discourage, but
I don't know how to carry that principle out in this instance.

Eliminate this function's need for an ASTContext while we're at it.

This bug affects the ABI, and fixing it brings us into accord with
the Itanium ABI (and GCC's implementation of it), but, obviously,
technically breaks full compatibility with previous releases of Clang.
Just letting you know.

llvm-svn: 153168

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Change CollectPrimaryBases to collect the bases in the right order. Fixes one half of PR9660.

llvm-svn: 129252

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

llvm-svn: 113092

Rework when and how vtables are emitted, by tracking where vtables are
"used" (e.g., we will refer to the vtable in the generated code) and
when they are defined (i.e., because we've seen the key fun

Rework when and how vtables are emitted, by tracking where vtables are
"used" (e.g., we will refer to the vtable in the generated code) and
when they are defined (i.e., because we've seen the key function
definition). Previously, we were effectively tracking "potential
definitions" rather than uses, so we were a bit too eager about emitting
vtables for classes without key functions.

The new scheme:
- For every use of a vtable, Sema calls MarkVTableUsed() to indicate
the use. For example, this occurs when calling a virtual member
function of the class, defining a constructor of that class type,
dynamic_cast'ing from that type to a derived class, casting
to/through a virtual base class, etc.
- For every definition of a vtable, Sema calls MarkVTableUsed() to
indicate the definition. This happens at the end of the translation
unit for classes whose key function has been defined (so we can
delay computation of the key function; see PR6564), and will also
occur with explicit template instantiation definitions.
- For every vtable defined/used, we mark all of the virtual member
functions of that vtable as defined/used, unless we know that the key
function is in another translation unit. This instantiates virtual
member functions when needed.
- At the end of the translation unit, Sema tells CodeGen (via the
ASTConsumer) which vtables must be defined (CodeGen will define
them) and which may be used (for which CodeGen will define the
vtables lazily).

From a language perspective, both the old and the new schemes are
permissible: we're allowed to instantiate virtual member functions
whenever we want per the standard. However, all other C++ compilers
were more lazy than we were, and our eagerness was both a performance
issue (we instantiated too much) and a portability problem (we broke
Boost test cases, which now pass).

Notes:
(1) There's a ton of churn in the tests, because the order in which
vtables get emitted to IR has changed. I've tried to isolate some of
the larger tests from these issues.
(2) Some diagnostics related to
implicitly-instantiated/implicitly-defined virtual member functions
have moved to the point of first use/definition. It's better this
way.
(3) I could use a review of the places where we MarkVTableUsed, to
see if I missed any place where the language effectively requires a
vtable.

Fixes PR7114 and PR6564.

llvm-svn: 103718

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Fix a bug where we would sometimes incorrectly mark an vtable function as unused.

llvm-svn: 101643

Split adding the primary virtual base offsets out into a separate pass. This fixes a bug where we would lay out virtual bases in the wrong order.

llvm-svn: 101373

Typo.

llvm-svn: 101015

Fix another bug where we wouldn't generate secondary vtables for construction vtables in some cases.

llvm-svn: 100998

Fix a bug where we were adding too many vcall offsets in some cases.

llvm-svn: 100985

Fix another vbase layout bug.

llvm-svn: 100952

Fix a bug where we would add the same function twice in a vtable.

llvm-svn: 100949

Simplify the virtual base layout code and fix a bug where we wouldn't store the offset for a virtual base.

llvm-svn: 100940