Commit Graph

38 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
Bruno Ricci eb10b065f2
[clang] Pass the NamedDecl* instead of the DeclarationName into many diagnostics.
Background:
-----------
There are two related argument types which can be sent into a diagnostic to
display the name of an entity: DeclarationName (ak_declarationname) or
NamedDecl* (ak_nameddecl) (there is also ak_identifierinfo for
IdentifierInfo*, but we are not concerned with it here).

A DeclarationName in a diagnostic will just be streamed to the output,
which will directly result in a call to DeclarationName::print.

A NamedDecl* in a diagnostic will also ultimately result in a call to
DeclarationName::print, but with two customisation points along the way:

The first customisation point is NamedDecl::getNameForDiagnostic which is
overloaded by FunctionDecl, ClassTemplateSpecializationDecl and
VarTemplateSpecializationDecl to print the template arguments, if any.

The second customisation point is NamedDecl::printName. By default it just
streams the stored DeclarationName into the output but it can be customised
to provide a user-friendly name for an entity. It is currently overloaded by
DecompositionDecl and MSGuidDecl.

What this patch does:
---------------------
For many diagnostics a DeclarationName is used instead of the NamedDecl*.
This bypasses the two customisation points mentioned above. This patches fix
this for diagnostics in Sema.cpp, SemaCast.cpp, SemaChecking.cpp, SemaDecl.cpp,
SemaDeclAttr.cpp, SemaDecl.cpp, SemaOverload.cpp and SemaStmt.cpp.

I have only modified diagnostics where I could construct a test-case which
demonstrates that the change is appropriate (either with this patch or the next
one).

Reviewed By: erichkeane, aaron.ballman

Differential Revision: https://reviews.llvm.org/D84656
2020-07-28 10:30:35 +01:00
Richard Smith 065fc1eafe PR45521: Preserve the value kind when performing a standard conversion
sequence on a glvalue expression.

If the sequence is supposed to perform an lvalue-to-rvalue conversion,
then one will be specified as the first conversion in the sequence.
Otherwise, one should not be invented.
2020-07-07 18:28:28 -07:00
Anastasia Stulova 1da9e4c910 [Sema] Improved diagnostic for qualifiers in reference binding
Improved wording and also simplified by using printing
method from qualifiers.

Differential Revision: https://reviews.llvm.org/D62914

llvm-svn: 364023
2019-06-21 10:50:02 +00:00
Nicolas Lesser 8217a2ab4f [C++11] Fix warning when dropping cv-qualifiers when assigning to a reference with a braced initializer list
llvm-svn: 336922
2018-07-12 17:43:49 +00:00
Richard Smith d186829093 Fix printing of reference-to-reference types.
Previously we would sometimes print these as 'T &&&' or even 'T &&&&'.

llvm-svn: 331137
2018-04-29 05:33:38 +00:00
Richard Trieu d3967635bc Fix typo from r237482. "to reference of type" --> "to reference to type"
llvm-svn: 237507
2015-05-16 01:39:39 +00:00
Richard Trieu f956a49e6d When emitting a dropped qualifier error, show which qualifiers are dropped.
llvm-svn: 237505
2015-05-16 01:27:03 +00:00
Richard Trieu 0ff51f39de Reverse the order of types in the reference dropping qualifiers error.
The error has the form ... 'int' ... 'const int' ... dropped qualifiers.  At
first glance, it appears that the const qualifier is added.  Reverse the types
so that the second type is less qualified than the first.

llvm-svn: 237482
2015-05-15 22:07:49 +00:00
Anastasia Stulova e8d88ac185 Reverted OpenCL2.0 atomic type commits r231932, r231935
(caused undesirable update of -std flag to use _Atomic)  

llvm-svn: 231942
2015-03-11 17:26:37 +00:00
Anastasia Stulova 0cb5d3333a OpenCL: CL2.0 atomic types
OpenCL C Spec v2.0 Section 6.13.11

- Made c11 _Atomic being accepted only for c11 compilations

- Implemented CL2.0 atomics by aliasing them to the corresponding c11 atomic types using implicit typedef

- Added diagnostics for atomics Khronos extension enabling

llvm-svn: 231932
2015-03-11 15:57:53 +00:00
Nathan Sidwell 44b21749b9 PR6037
Warn on inaccessible direct base

llvm-svn: 226423
2015-01-19 01:44:02 +00:00
Richard Smith 4025944307 PR13110: Add a -Wignored-qualifiers warning when ignoring a const, volatile, or
_Atomic qualifier applied to a reference type.

llvm-svn: 201620
2014-02-19 00:13:27 +00:00
Richard Smith 2eabf78eb6 When copy-initializing a temporary for a reference binding, don't allow use of
explicit constructors.

llvm-svn: 183879
2013-06-13 00:57:57 +00:00
Hans Wennborg d799a2b3b9 Better wording for reference self-initialization warning.
llvm-svn: 162198
2012-08-20 08:52:22 +00:00
Hans Wennborg e1fdb059c6 Warn about self-initialization of references.
Initializing a reference with itself, e.g. "int &a = a;" seems like a
very bad idea.

llvm-svn: 162093
2012-08-17 10:12:33 +00:00
Chandler Carruth 41c6dcc734 Fix a crash-on-valid that has been here for a very long time:
const int &x = x;

This crashed by inifinetly recursing within the lvalue evaluation
routine. I've added a (somewhat) braindead way of preventing this
recursion. If folks have better suggestions for how to avoid it I'm all
ears.

That said, we have some work to do. This doesn't trigger a single
warning for uninitialized, self-initialized or otherwise completely
wrong code. In some senses, the crash was almost better.

llvm-svn: 138239
2011-08-22 17:24:56 +00:00
John McCall 36459fdbad Add another case to the whitelist of cast kinds that can convert to bool.
Fixes PR8608.

llvm-svn: 119293
2010-11-16 00:12:50 +00:00
Chris Lattner 53fa04909c make clang print types as "const int *" instead of "int const*",
which is should have done from the beginning.  As usual, the most
fun with this sort of change is updating all the testcases.

llvm-svn: 113090
2010-09-05 00:04:01 +00:00
Douglas Gregor 3b05bdba5a Teach ASTContext::getUnqualifiedArrayType() how to look through
typedefs. As a drive-by, teach hit how to build VLA types, since those
will eventually be supported in C++.

llvm-svn: 103958
2010-05-17 18:45:21 +00:00
Douglas Gregor 454a5b65d4 Warn about non-aggregate classes with no user-declared constructors
that have reference or const scalar members, since those members can
never be initializer or modified. Fixes <rdar://problem/7804350>.

llvm-svn: 101316
2010-04-15 00:00:53 +00:00
John McCall 85f9055955 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
2010-03-10 11:27:22 +00:00
Anders Carlsson 8abde4b447 Diagnose binding a non-const reference to a vector element.
llvm-svn: 94963
2010-01-31 17:18:49 +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 3e1e527826 Reimplement reference initialization (C++ [dcl.init.ref]) using the
new notion of an "initialization sequence", which encapsulates the
computation of the initialization sequence along with diagnostic
information and the capability to turn the computed sequence into an
expression. At present, I've only switched one CheckReferenceInit
callers over to this new mechanism; more will follow.

Aside from (hopefully) being much more true to the standard, the
diagnostics provided by this reference-initialization code are a bit
better than before. Some examples:

p5-var.cpp:54:12: error: non-const lvalue reference to type 'struct
Derived'
      cannot bind to a value of unrelated type 'struct Base'
  Derived &dr2 = b; // expected-error{{non-const lvalue reference to
  ...
           ^     ~
p5-var.cpp:55:9: error: binding of reference to type 'struct Base' to
a value of
      type 'struct Base const' drops qualifiers
  Base &br3 = bc; // expected-error{{drops qualifiers}}
        ^     ~~

p5-var.cpp:57:15: error: ambiguous conversion from derived class
      'struct Diamond' to base class 'struct Base':
    struct Diamond -> struct Derived -> struct Base
    struct Diamond -> struct Derived2 -> struct Base
  Base &br5 = diamond; // expected-error{{ambiguous conversion from
      ...
              ^~~~~~~
p5-var.cpp:59:9: error: non-const lvalue reference to type 'long'
      cannot bind to
      a value of unrelated type 'int'
  long &lr = i; // expected-error{{non-const lvalue reference to type
      ...
        ^    ~

p5-var.cpp:74:9: error: non-const lvalue reference to type 'struct
Base' cannot
      bind to a temporary of type 'struct Base'
  Base &br1 = Base(); // expected-error{{non-const lvalue reference to
  ...
        ^     ~~~~~~

p5-var.cpp:102:9: error: non-const reference cannot bind to bit-field
'i'
  int & ir1 = (ib.i); // expected-error{{non-const reference cannot
  ...
        ^     ~~~~~~
p5-var.cpp:98:7: note: bit-field is declared here
  int i : 17; // expected-note{{bit-field is declared here}}
      ^

llvm-svn: 90992
2009-12-09 23:02:17 +00:00
Douglas Gregor 96ab942a69 Make C++ temporary-related expressions provide proper source-range information.
llvm-svn: 82665
2009-09-23 22:51:26 +00:00
Daniel Dunbar a45cf5b6b0 Rename clang to clang-cc.
Tests and drivers updated, still need to shuffle dirs.

llvm-svn: 67602
2009-03-24 02:24:46 +00:00
Sebastian Redl 0f8b23f71f Almost complete implementation of rvalue references. One bug, and a few unclear areas. Maybe Doug can shed some light on some of the fixmes.
llvm-svn: 67059
2009-03-16 23:22:08 +00:00
Douglas Gregor ec8806e8ec Removed the warning
warning: statement was disambiguated as declaration

because it is currently firing in cases where the declaration would
not actually parse as a statement. We'd love to bring this warning
back if we can make it more accurate.

llvm-svn: 61137
2008-12-17 16:19:15 +00:00
Chris Lattner e3d20d9545 Convert IdentifierInfo's to be printed the same as DeclarationNames
with implicit quotes around them.  This has a bunch of follow-on 
effects and requires tweaking to a whole lot of code.  This causes
a regression in two tests (xfailed) by causing it to emit things like:

  Line 10: duplicate interface declaration for category 'MyClass1' ('Category1')

instead of:

  Line 10: duplicate interface declaration for category 'MyClass1(Category1)'

I will fix this in a follow-up commit.

As part of this, I had to start switching stuff to use ->getDeclName() instead
of Decl::getName() for consistency.  This is good, but I was planning to do this
as an independent patch.  There will be several follow-on patches
to clean up some of the mess, but this patch is already too big.

llvm-svn: 59917
2008-11-23 21:45:46 +00:00
Douglas Gregor 66583c5ff3 Implement C++ DR 106 and C++ DR 540, both of which deal with
reference-collapsing. 

Implement diagnostic for formation of a reference to cv void.

Drop cv-qualifiers added to a reference type when the reference type
comes from a typedef.

llvm-svn: 58612
2008-11-03 15:51:28 +00:00
Douglas Gregor 9774aa13c7 Temporary disable the const-object-declaration-without-initializer check, because it depends on linkage-specifier semantics we don't yet have
llvm-svn: 58377
2008-10-29 13:50:18 +00:00
Douglas Gregor 8e1cf608dc Implement initialization of a reference (C++ [dcl.init.ref]) as part
of copy initialization. Other pieces of the puzzle:

  - Try/Perform-ImplicitConversion now handles implicit conversions
    that don't involve references.
  - Try/Perform-CopyInitialization uses
    CheckSingleAssignmentConstraints for C. PerformCopyInitialization
    is now used for all argument passing and returning values from a
    function.
  - Diagnose errors with declaring references and const values without
    an initializer. (Uses a new Action callback, ActOnUninitializedDecl).
  
We do not yet have implicit conversion sequences for reference
binding, which means that we don't have any overloading support for
reference parameters yet.

llvm-svn: 58353
2008-10-29 00:13:59 +00:00
Argyrios Kyrtzidis 3014572ea2 Move the C++ Sema tests into a separate SemaCXX directory.
llvm-svn: 54853
2008-08-16 20:53:59 +00:00