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32 Commits

Author SHA1 Message Date
Matheus Izvekov 15f3cd6bfc
[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
2022-07-27 11:10:54 +02:00
Jonas Devlieghere 888673b6e3
Revert "[clang] Implement ElaboratedType sugaring for types written bare"
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.
2022-07-14 21:17:48 -07:00
Matheus Izvekov 7c51f02eff
[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
2022-07-15 04:16:55 +02:00
Jonas Devlieghere 3968936b92
Revert "[clang] Implement ElaboratedType sugaring for types written bare"
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/
2022-07-13 09:20:30 -07:00
Matheus Izvekov bdc6974f92
[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
2022-07-13 02:10:09 +02:00
Richard Smith 9dbb0886ea Perform lvalue conversions on the left of a pseudo-destructor call 'p->~T()'.
Previously we failed to convert 'p' from array/function to pointer type,
and to represent the load of 'p' in the AST. The latter causes problems
for constant evaluation.
2020-10-14 22:09:01 -07:00
Richard Smith a5458bb0d6 Don't claim template names that name non-templates are undeclared. 2020-03-29 13:15:30 -07:00
Richard Smith 499b2a8d63 PR45294: Fix handling of assumed template names looked up in the lexical
scope.

There are a few contexts in which we assume a name is a template name;
if such a context is one where we should perform an unqualified lookup,
and lookup finds nothing, we would form a dependent template name even
if the name is not dependent. This happens in particular for the lookup
of a pseudo-destructor.

In passing, rename ActOnDependentTemplateName to just ActOnTemplateName
given that we apply it for non-dependent template names too.
2020-03-27 21:07:06 -07:00
Richard Smith 502915c619 PR45142: 'template ~X<T>' is ill-formed; reject it rather than crashing. 2020-03-23 15:07:06 -07:00
Richard Smith 0e3a487784 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.
2020-02-07 18:40:41 -08:00
Richard Smith 04f131da0b DR1753: Don't permit x.NS::~T() as a pseudo-destructor name.
When used as qualified names, pseudo-destructors are always named as if
they were members of the type, never as members of the namespace
enclosing the type.
2020-01-24 18:53:50 -08:00
Richard Smith 9e77f524b5 Fix handling of class member access into a vector type.
When handling a member access into a non-class, non-ObjC-object type, we
would perform a lookup into the surrounding scope as if for an
unqualified lookup. If the member access was followed by a '<' and this
lookup (or the typo-correction for it) found a template name, we'd treat
the member access as naming that template.

Now we treat such accesses as never naming a template if the type of the
object expression is of vector type, so that vector component accesses
are never misinterpreted as naming something else. This is not entirely
correct, since it is in fact valid to name a template from the enclosing
scope in this context, when invoking a pseudo-destructor for the vector
type via an alias template, but that's very much a corner case, and this
change leaves that case only as broken as the corresponding case for
Objective-C types is.

This incidentally adds support for dr2292, which permits a 'template'
keyword at the start of a member access naming a pseudo-destructor.

llvm-svn: 368940
2019-08-14 22:57:50 +00:00
Alex Lorenz 76377dcf99 Print nested name specifiers for typedefs and type aliases
Printing typedefs or type aliases using clang_getTypeSpelling() is missing the
namespace they are defined in. This is in contrast to other types that always
yield the full typename including namespaces.

Patch by Michael Reiher!

Differential Revision: https://reviews.llvm.org/D29944

llvm-svn: 297465
2017-03-10 15:04:58 +00:00
Alex Lorenz 56fb6fef50 [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
2017-01-20 15:38:58 +00:00
Eric Christopher 6e11073b3e Unify warnings/errors from "maybe you meant" to "did you mean".
llvm-svn: 233981
2015-04-02 22:10:06 +00:00
David Majnemer ced8bdf74a Sema: Parenthesized bound destructor member expressions can be called
We would wrongfully reject (a.~A)() in both the destructor and
pseudo-destructor cases.

This fixes PR22668.

llvm-svn: 230512
2015-02-25 17:36:15 +00:00
Richard Smith af41696bc4 Per [basic.lookup.classref]p3, in an expression of the form p->~type-name, the
type-name is looked up in the context of the complete postfix-expression. Don't
forget to pass the scope into this lookup when the type-name is a template-id;
it might name an alias template which can't be found within the class itself.

Bug spotted by Johannes Schaub on #llvm.

llvm-svn: 168011
2012-11-15 00:31:27 +00:00
David Blaikie 1d578782fa Support decltype in pseudo destructors and dependent destructor calls.
Reviewed by Eli Friedman.

llvm-svn: 146738
2011-12-16 16:03:09 +00:00
Douglas Gregor f39a8dd445 Don't crash when transforming an ill-formed pseudo-destructor
expression. Fixes PR11339.

llvm-svn: 144159
2011-11-09 02:19:47 +00:00
Douglas Gregor 4cf85a725a When clearing a LookupResult structure, clear out the naming class,
too. Fixes PR7900.

While I'm in this area, improve the diagnostic when the type being
destroyed doesn't match either of the types we found.

llvm-svn: 127041
2011-03-04 22:32:08 +00:00
John McCall b86a6b830e Allow pseudo-destructors to be called on qualified pointers. Patch by
Troy Straszheim!

llvm-svn: 105823
2010-06-11 17:36:40 +00:00
Douglas Gregor 0d5b0a1e5e ActOnPseudoDestructorExpr now performs all semantic analysis for
pseudo-destructor expressions, and builds the CXXPseudoDestructorExpr
node directly. Currently, this only affects pseudo-destructor
expressions when they are parsed, but not after template
instantiation. That's coming next...

Improve parsing of pseudo-destructor-names. When parsing the
nested-name-specifier and we hit the sequence of tokens X :: ~, query
the actual module to determine whether X is a type-name (in which case
the X :: is part of the pseudo-destructor-name but not the
nested-name-specifier) or not (in which case the X :: is part of the
nested-name-specifier). 

llvm-svn: 97058
2010-02-24 21:29:12 +00:00
Douglas Gregor 46841e1bd9 Implement crazy destructor name lookup semantics differently in
C++98/03 and C++0x, since the '0x semantics break valid C++98/03
code. This new mess is tracked by core issue 399, which is still
unresolved.

Fixes PR6358 and PR6359.

llvm-svn: 96836
2010-02-23 00:15:22 +00:00
Douglas Gregor 90d554ecb3 Implement support for parsing pseudo-destructor expression with a nested-name-specifier, e.g.,
typedef int Int;
  int *p;
  p->Int::~Int();

This weakens the invariant that the only types in nested-name-specifiers are tag types (restricted to class types in C++98/03). However, we weaken this invariant as little as possible, accepting arbitrary types in nested-name-specifiers only when we're in a member access expression that looks like a pseudo-destructor expression.

llvm-svn: 96743
2010-02-21 18:36:56 +00:00
Chandler Carruth 8f2548112e Commiting a revert from dgregor of a bit of destructor logic until we can
figure out how not to break lots of code using this. See PR6358 and PR6359 for
motivating examples. FIXME's left in the code and the test.

llvm-svn: 96733
2010-02-21 10:19:54 +00:00
Douglas Gregor fe17d2550b Improve parsing and instantiation of destructor names, so that we can
now cope with the destruction of types named as dependent templates,
e.g.,

  y->template Y<T>::~Y()

Nominally, we implement C++0x [basic.lookup.qual]p6. However, we don't
follow the letter of the standard here because that would fail to
parse

  template<typename T, typename U>
  X0<T, U>::~X0() { }

properly. The problem is captured in core issue 339, which gives some
(but not enough!) guidance. I expect to revisit this code when the
resolution of 339 is clear, and/or we start capturing better source
information for DeclarationNames.

Fixes PR6152.

llvm-svn: 96367
2010-02-16 19:09:40 +00:00
Daniel Dunbar 8fbe78f6fc Update tests to use %clang_cc1 instead of 'clang-cc' or 'clang -cc1'.
- This is designed to make it obvious that %clang_cc1 is a "test variable"
   which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
   can be useful to redefine what gets run as 'clang -cc1' (for example, to set
   a default target).

llvm-svn: 91446
2009-12-15 20:14:24 +00:00
Douglas Gregor a25d65d1b6 Implement C++ [basic.lookup.classref]p3, which states how the type
name 'T' is looked up in the expression

  t.~T()

Previously, we weren't looking into the type of "t", and therefore
would fail when T actually referred to an injected-class-name. Fixes
PR5530.

llvm-svn: 89493
2009-11-20 22:03:38 +00:00
Daniel Dunbar 8b57697954 Eliminate &&s in tests.
- 'for i in $(find . -type f); do sed -e 's#\(RUN:.*[^ ]\) *&& *$#\1#g' $i | FileUpdate $i; done', for the curious.

llvm-svn: 86430
2009-11-08 01:45:36 +00:00
Douglas Gregor bddb73fa1d If a destructor is referenced or a pseudo-destructor expression is
formed without a trailing '(', diagnose the error (these expressions
must be immediately called), emit a fix-it hint, and fix the code.

llvm-svn: 81015
2009-09-04 18:29:40 +00:00
Douglas Gregor ad8a336b40 Implement AST, semantics, and CodeGen for C++ pseudo-destructor
expressions, e.g.,

  p->~T()

when p is a pointer to a scalar type. 

We don't currently diagnose errors when pseudo-destructor expressions
are used in any way other than by forming a call.

llvm-svn: 81009
2009-09-04 17:36:40 +00:00
Anders Carlsson c24fc2949e More support for pseudo dtors.
llvm-svn: 80129
2009-08-26 19:22:42 +00:00