552 Commits

Author SHA1 Message Date
cor3ntin
326657f567
[Clang] Address post commit feedbacks in #89906 (#90495)
* Fix a leak
* Fix a maybe unused warning
* Fix incorrect cxx_status entry
2024-04-29 22:11:09 +02:00
cor3ntin
6dd90616c4
[Clang] Implement C++26 Attributes for Structured Bindings (P0609R3) (#89906)
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p0609r3.pdf

We support this feature in all language mode.

maybe_unused applied to a binding makes the whole declaration unused.
2024-04-28 20:25:44 +02:00
Chuanqi Xu
d86cc73bbf [NFC] [Serialization] Avoid using DeclID directly as much as possible
This patch tries to remove all the direct use of DeclID except the real
low level reading and writing. All the use of DeclID is converted to
the use of LocalDeclID or GlobalDeclID. This is helpful to increase the
readability and type safety.
2024-04-25 14:59:09 +08:00
Chuanqi Xu
72b58146b1 Revert "[NFC] [Serialization] Avoid using DeclID directly as much as possible"
This reverts commit 42070a5c092ed420bf92ebf38229c594885e94c7.

I forgot to touch lldb.
2024-04-25 14:26:07 +08:00
Chuanqi Xu
42070a5c09 [NFC] [Serialization] Avoid using DeclID directly as much as possible
This patch tries to remove all the direct use of DeclID except the real
low level reading and writing. All the use of DeclID is converted to
the use of LocalDeclID or GlobalDeclID. This is helpful to increase the
readability and type safety.
2024-04-25 14:14:05 +08:00
Chuanqi Xu
c2a98fdeb3
[NFC] Move DeclID from serialization/ASTBitCodes.h to AST/DeclID.h (#89873)
Previously, the DeclID is defined in serialization/ASTBitCodes.h under
clang::serialization namespace. However, actually the DeclID is not
purely used in serialization part. The DeclID is already widely used in
AST and all around the clang project via classes like `LazyPtrDecl` or
calling `ExternalASTSource::getExernalDecl()`. All such uses are via the
raw underlying type of `DeclID` as `uint32_t`. This is not pretty good.

This patch moves the DeclID class family to a new header `AST/DeclID.h`
so that the whole project can use the wrapped class `DeclID`,
`GlobalDeclID` and `LocalDeclID` instead of the raw underlying type.
This can improve the readability and the type safety.
2024-04-25 13:53:22 +08:00
Chuanqi Xu
aac695da42 [NFC] [Serialization] Use semantical type 'DeclID' for 'CreateDeserialized'
Previously we use 'unsigned' as the type of ID in 'CreateDeserialized'.

And the type of `DeclID` in serialization is 'uint32_t', so there is
minor inconsistency.

Also more importantly, if we want to extend the type of DeclID from
uint32_t to uint64_t, we may be in trouble due to we forgot updating the
a lot of 'CreateDeserialized'.

So this patch tries to use semantical type 'DeclID' for
'*Decl::CreateDeserialized' to make sure it is tightly consistent.
2024-04-19 16:24:47 +08:00
Chuanqi Xu
d26dd58ca5 [StmtProfile] Don't profile the body of lambda expressions
Close https://github.com/llvm/llvm-project/issues/87609

We tried to profile the body of the lambda expressions in
https://reviews.llvm.org/D153957. But as the original comments show,
it is indeed dangerous. After we tried to skip calculating the ODR
hash values recently, we have fall into this trap twice.

So in this patch, I choose to not profile the body of the lambda
expression. The signature of the lambda is still profiled.
2024-04-16 15:41:26 +08:00
Nikolas Klauser
ed06b847d4
Revert "[Clang] Reduce the size of Decl and classes derived from it" (#88654)
Reverts llvm/llvm-project#87361

On 32 bit platforms there is only a single bit available in the
`DeclCtx`, resulting in an assertion failure.
2024-04-14 12:25:49 +02:00
Nikolas Klauser
c6f9c84e49
[Clang] Reduce the size of Decl and classes derived from it (#87361)
Class | Old size (in bytes) | New size (in bytes)

----------------------------------|---------------------|--------------------
Decl                              | 40                  | 32
AccessSpecDecl                    | 40                  | 40
BlockDecl                         | 128                 | 120
CapturedDecl                      | 88                  | 80
EmptyDecl                         | 40                  | 32
ExportDecl                        | 80                  | 72
ExternCContextDecl                | 72                  | 64
FileScopeAsmDecl                  | 56                  | 48
FriendDecl                        | 64                  | 56
FriendTemplateDecl                | 64                  | 64
ImplicitConceptSpecializationDecl | 40                  | 40
ImportDecl                        | 56                  | 48
LifetimeExtendedTemporaryDecl     | 72                  | 64
LinkageSpecDecl                   | 80                  | 72
NamedDecl                         | 48                  | 40
ObjCPropertyImplDecl              | 96                  | 88
PragmaCommentDecl                 | 40                  | 40
PragmaDetectMismatchDecl          | 48                  | 40
RequiresExprBodyDecl              | 72                  | 64
StaticAssertDecl                  | 64                  | 56
TopLevelStmtDecl                  | 88                  | 80
TranslationUnitDecl               | 104                 | 96
BaseUsingDecl                     | 56                  | 48
UsingDecl                         | 88                  | 80
UsingEnumDecl                     | 72                  | 64
HLSLBufferDecl                    | 96                  | 88
LabelDecl                         | 80                  | 72
NamespaceAliasDecl                | 96                  | 88
NamespaceDecl                     | 112                 | 104
ObjCCompatibleAliasDecl           | 56                  | 48
ObjCContainerDecl                 | 88                  | 80
ObjCMethodDecl                    | 136                 | 128
ObjCPropertyDecl                  | 128                 | 120
TemplateDecl                      | 64                  | 56
BuiltinTemplateDecl               | 72                  | 64
TypeDecl                          | 64                  | 56
UnresolvedUsingIfExistsDecl       | 48                  | 40
UsingDirectiveDecl                | 88                  | 80
UsingPackDecl                     | 64                  | 56
UsingShadowDecl                   | 80                  | 72
ValueDecl                         | 56                  | 48

When parsing libc++'s `<string>` header the used memory is reduced from
42.8MB to 42.5MB.
2024-04-14 12:08:30 +02:00
Chuanqi Xu
468dc32ff5 [NFC] Make DeclContext::noload_lookup() accept transparent context
Now the `DeclContext::noload_lookup()` asserts that 'this' is not a
transparent context. However, this is not consistent with
`DeclContext::lookup()`, which will lookup into its parent context if
'this' is a transparent context.

This patch makes the behavior of `DeclContext::noload_lookup()` to be
consistent with `DeclContext::lookup()`, to lookup into the parent
context if 'this' is a transparent context.
2024-04-03 15:03:07 +08:00
Chuanqi Xu
abfc5efb55 [NFC] [Decl] Introduce Decl::isFromExplicitGlobalModule
Introduce `Decl::isFromExplicitGlobalModule` to replace the
`D->getOwningModule() && D->getOwningModule()->isExplicitGlobalModule()`
pattern to save some typings.
2024-03-29 16:21:02 +08:00
Chuanqi Xu
3f6bc1adf8 [C++20] [Moduls] Avoid computing odr hash for functions from comparing constraint expression
Previously we disabled to compute ODR hash for declarations from the
global module fragment. However, we missed the case that the functions
lives in the concept requiments (see the attached the test files for
example). And the mismatch causes the potential crashment.

Due to we will set the function body as lazy after we deserialize it and
we will only take its body when needed. However, we don't allow to take
the body during deserializing. So it is actually potentially problematic
if we set the body as lazy first and computing the hash value of the
function, which requires to deserialize its body. So we will meet a
crash here.

This patch tries to solve the issue by not taking the body of the
function from GMF. Note that we can't skip comparing the constraint
expression from the GMF directly since it is an key part of the
function selecting and it may be the reason why we can't return 0
directly for `FunctionDecl::getODRHash()` from the GMF.
2024-03-11 11:39:21 +08:00
Stefan Gränitz
4b70d17bcf
[clang-repl] Names declared in if conditions and for-init statements are local to the inner context (#84150)
Make TopLevelStmtDecl a DeclContext so that variables defined in statements
are attached to the TopLevelDeclContext. This fixes redefinition errors
from variables declared in if conditions and for-init statements. These
must be local to the inner context (C++ 3.3.2p4), but they had generated
definitions on global scope instead.

This PR makes the TopLevelStmtDecl looking more like a FunctionDecl and
that's fine because the FunctionDecl is very close in terms of semantics.

Additionally, ActOnForStmt() requires a CompoundScope when processing a
NullStmt body.

---------

Co-authored-by: Vassil Vassilev <v.g.vassilev@gmail.com>
2024-03-07 14:27:04 +01:00
Fred Tingaud
c609211d91
[clang] Fix isInStdNamespace for Decl flagged extern c++ (#81776)
The MSVC STL implementation declares multiple classes using:

```cpp
namespace std {
  extern "C++" class locale {
    ...
  };
}
```

`isInStdNamespace` uses the first DeclContext to check whether a Decl is
inside the `std` namespace. Here, the first DeclContext of the `locale`
Decl is a LinkageSpecDecl so the method will return false.
We need to skip this LinkageSpecDecl to find the first DeclContext of
type Namespace and actually check whether we're in the `std` namespace.
2024-02-15 14:55:25 +01:00
Bill Wendling
00b6d032a2 [Clang] Implement the 'counted_by' attribute (#76348)
The 'counted_by' attribute is used on flexible array members. The
argument for the attribute is the name of the field member holding the
count of elements in the flexible array. This information is used to
improve the results of the array bound sanitizer and the
'__builtin_dynamic_object_size' builtin. The 'count' field member must
be within the same non-anonymous, enclosing struct as the flexible array
member. For example:

```
  struct bar;
  struct foo {
    int count;
    struct inner {
      struct {
        int count; /* The 'count' referenced by 'counted_by' */
      };
      struct {
        /* ... */
        struct bar *array[] __attribute__((counted_by(count)));
      };
    } baz;
  };
```

This example specifies that the flexible array member 'array' has the
number of elements allocated for it in 'count':

```
  struct bar;
  struct foo {
    size_t count;
     /* ... */
    struct bar *array[] __attribute__((counted_by(count)));
  };
```

This establishes a relationship between 'array' and 'count';
specifically that 'p->array' must have *at least* 'p->count' number of
elements available. It's the user's responsibility to ensure that this
relationship is maintained throughout changes to the structure.

In the following, the allocated array erroneously has fewer elements
than what's specified by 'p->count'. This would result in an
out-of-bounds access not not being detected:

```
  struct foo *p;

  void foo_alloc(size_t count) {
    p = malloc(MAX(sizeof(struct foo),
                   offsetof(struct foo, array[0]) + count *
                       sizeof(struct bar *)));
    p->count = count + 42;
  }
```

The next example updates 'p->count', breaking the relationship
requirement that 'p->array' must have at least 'p->count' number of
elements available:

```
  void use_foo(int index, int val) {
    p->count += 42;
    p->array[index] = val; /* The sanitizer can't properly check this access */
  }
```

In this example, an update to 'p->count' maintains the relationship
requirement:

```
  void use_foo(int index, int val) {
    if (p->count == 0)
      return;
    --p->count;
    p->array[index] = val;
  }
```
2024-01-16 14:26:12 -08:00
Rashmi Mudduluru
a511c1a9ec
Revert "[Clang] Implement the 'counted_by' attribute (#76348)"
This reverts commit 164f85db876e61cf4a3c34493ed11e8f5820f968.
2024-01-15 18:37:52 -08:00
Bill Wendling
164f85db87 [Clang] Implement the 'counted_by' attribute (#76348)
The 'counted_by' attribute is used on flexible array members. The
argument for the attribute is the name of the field member holding the
count of elements in the flexible array. This information is used to
improve the results of the array bound sanitizer and the
'__builtin_dynamic_object_size' builtin. The 'count' field member must
be within the same non-anonymous, enclosing struct as the flexible array
member. For example:

```
  struct bar;
  struct foo {
    int count;
    struct inner {
      struct {
        int count; /* The 'count' referenced by 'counted_by' */
      };
      struct {
        /* ... */
        struct bar *array[] __attribute__((counted_by(count)));
      };
    } baz;
  };
```

This example specifies that the flexible array member 'array' has the
number of elements allocated for it in 'count':

```
  struct bar;
  struct foo {
    size_t count;
     /* ... */
    struct bar *array[] __attribute__((counted_by(count)));
  };
```

This establishes a relationship between 'array' and 'count';
specifically that 'p->array' must have *at least* 'p->count' number of
elements available. It's the user's responsibility to ensure that this
relationship is maintained throughout changes to the structure.

In the following, the allocated array erroneously has fewer elements
than what's specified by 'p->count'. This would result in an
out-of-bounds access not not being detected:

```
  struct foo *p;

  void foo_alloc(size_t count) {
    p = malloc(MAX(sizeof(struct foo),
                   offsetof(struct foo, array[0]) + count *
                       sizeof(struct bar *)));
    p->count = count + 42;
  }
```

The next example updates 'p->count', breaking the relationship
requirement that 'p->array' must have at least 'p->count' number of
elements available:

```
  void use_foo(int index, int val) {
    p->count += 42;
    p->array[index] = val; /* The sanitizer can't properly check this access */
  }
```

In this example, an update to 'p->count' maintains the relationship
requirement:

```
  void use_foo(int index, int val) {
    if (p->count == 0)
      return;
    --p->count;
    p->array[index] = val;
  }
```
2024-01-10 22:20:31 -08:00
Nico Weber
2dce77201c Revert "[Clang] Implement the 'counted_by' attribute (#76348)"
This reverts commit fefdef808c230c79dca2eb504490ad0f17a765a5.

Breaks check-clang, see
https://github.com/llvm/llvm-project/pull/76348#issuecomment-1886029515

Also revert follow-on "[Clang] Update 'counted_by' documentation"

This reverts commit 4a3fb9ce27dda17e97341f28005a28836c909cfc.
2024-01-10 21:05:19 -05:00
Bill Wendling
fefdef808c
[Clang] Implement the 'counted_by' attribute (#76348)
The 'counted_by' attribute is used on flexible array members. The
argument for the attribute is the name of the field member holding the
count of elements in the flexible array. This information is used to
improve the results of the array bound sanitizer and the
'__builtin_dynamic_object_size' builtin. The 'count' field member must
be within the same non-anonymous, enclosing struct as the flexible array
member. For example:

```
  struct bar;
  struct foo {
    int count;
    struct inner {
      struct {
        int count; /* The 'count' referenced by 'counted_by' */
      };
      struct {
        /* ... */
        struct bar *array[] __attribute__((counted_by(count)));
      };
    } baz;
  };
```

This example specifies that the flexible array member 'array' has the
number of elements allocated for it in 'count':

```
  struct bar;
  struct foo {
    size_t count;
     /* ... */
    struct bar *array[] __attribute__((counted_by(count)));
  };
```

This establishes a relationship between 'array' and 'count';
specifically that 'p->array' must have *at least* 'p->count' number of
elements available. It's the user's responsibility to ensure that this
relationship is maintained throughout changes to the structure.

In the following, the allocated array erroneously has fewer elements
than what's specified by 'p->count'. This would result in an
out-of-bounds access not not being detected:

```
  struct foo *p;

  void foo_alloc(size_t count) {
    p = malloc(MAX(sizeof(struct foo),
                   offsetof(struct foo, array[0]) + count *
                       sizeof(struct bar *)));
    p->count = count + 42;
  }
```

The next example updates 'p->count', breaking the relationship
requirement that 'p->array' must have at least 'p->count' number of
elements available:

```
  void use_foo(int index, int val) {
    p->count += 42;
    p->array[index] = val; /* The sanitizer can't properly check this access */
  }
```

In this example, an update to 'p->count' maintains the relationship
requirement:

```
  void use_foo(int index, int val) {
    if (p->count == 0)
      return;
    --p->count;
    p->array[index] = val;
  }
```
2024-01-10 15:21:10 -08:00
Pol M
901a8160a8
[clang] Optimize castToDeclContext for 2% improvement in build times (#76825)
Optimize castToDeclContext for 2% improvement in build times
castToDeclContext is a heavily used function, and as such, it needs to
be kept as slim as feasible to preserve as much performance as possible.
To this end, it was observed that the function was generating suboptimal
assembly code, and putting the most common execution path in the longest
sequence of instructions. This patch addresses this by guiding the
compiler towards generating a lookup table of offsets, which can be used
to perform an addition on the pointer. This results in a 1-2%
improvement on debug builds (and a negligible improvement on release).

To achieve this, the switch was simplified to flatten the if statements
in the default branch. In order to make the values of the switch more
compact, encouraging LLVM to generate a look-up table instead of a jump
table, the AST TableGen generator was modified so it can take order
priority based on class inheritance. This combination allowed for a more
optimal generation of the function. Of note, 2 other functions with an
equivalent structure also needed to be modified.

Fixes #76824
2024-01-04 15:42:35 +01:00
Bill Wendling
cca4d6cfd2
Revert counted_by attribute feature (#75857)
There are many issues that popped up with the counted_by feature. The
patch #73730 has grown too large and approval is blocking Linux testing.

Includes reverts of:
commit 769bc11f684d ("[Clang] Implement the 'counted_by' attribute
(#68750)")
commit bc09ec696209 ("[CodeGen] Revamp counted_by calculations
(#70606)")
commit 1a09cfb2f35d ("[Clang] counted_by attr can apply only to C99
flexible array members (#72347)")
commit a76adfb992c6 ("[NFC][Clang] Refactor code to calculate flexible
array member size (#72790)")
commit d8447c78ab16 ("[Clang] Correct handling of negative and
out-of-bounds indices (#71877)")
Partial commit b31cd07de5b7 ("[Clang] Regenerate test checks (NFC)")

Closes #73168
Closes #75173
2023-12-18 15:16:09 -08:00
Bill Wendling
1a09cfb2f3
[Clang] counted_by attr can apply only to C99 flexible array members (#72347)
Ensure that we're dealing only with C99 flexible array members. I.e.
ones with incomplete types:

  struct s {
    int count;
    char array[]; /* note: no size specified */
  };

Authored-by: Bill Wendling <isanbard@gmail.com>
2023-11-15 08:27:06 -08:00
Chuanqi Xu
0f7aaeb324 [C++20] [Modules] Allow export from language linkage
Close https://github.com/llvm/llvm-project/issues/71347

Previously I misread the concept of module purview. I thought if a
declaration attached to a unnamed module, it can't be part of the module
purview. But after the issue report, I recognized that module purview is
more of a concept about locations instead of semantics.

Concretely, the things in the language linkage after module declarations
can be exported.

This patch refactors `Module::isModulePurview()` and introduces some
possible code cleanups.
2023-11-09 17:44:41 +08:00
Vlad Serebrennikov
65761200ce [clang][NFC] Refactor LinkageSpecDecl::LanguageIDs
This patch converts `LinkageSpecDecl::LanguageIDs` into scoped enum, and moves it to namespace scope, so that it can be forward-declared where required.
2023-11-01 16:44:34 +03:00
Bill Wendling
769bc11f68
[Clang] Implement the 'counted_by' attribute (#68750)
The 'counted_by' attribute is used on flexible array members. The
argument for the attribute is the name of the field member in the same
structure holding the count of elements in the flexible array. This
information can be used to improve the results of the array bound
sanitizer and the '__builtin_dynamic_object_size' builtin.

This example specifies the that the flexible array member 'array' has
the number of elements allocated for it in 'count':

  struct bar;
  struct foo {
    size_t count;
     /* ... */
    struct bar *array[] __attribute__((counted_by(count)));
  };

This establishes a relationship between 'array' and 'count',
specifically that 'p->array' must have *at least* 'p->count' number of
elements available. It's the user's responsibility to ensure that this
relationship is maintained through changes to the structure.

In the following, the allocated array erroneously has fewer elements
than what's specified by 'p->count'. This would result in an
out-of-bounds access not not being detected:

  struct foo *p;

  void foo_alloc(size_t count) {
    p = malloc(MAX(sizeof(struct foo),
                   offsetof(struct foo, array[0]) + count *
                       sizeof(struct bar *)));
    p->count = count + 42;
  }

The next example updates 'p->count', breaking the relationship
requirement that 'p->array' must have at least 'p->count' number of
elements available:

  struct foo *p;

  void foo_alloc(size_t count) {
    p = malloc(MAX(sizeof(struct foo),
                   offsetof(struct foo, array[0]) + count *
                       sizeof(struct bar *)));
    p->count = count + 42;
  }

  void use_foo(int index) {
    p->count += 42;
    p->array[index] = 0; /* The sanitizer cannot properly check this access */
  }

Reviewed By: nickdesaulniers, aaron.ballman

Differential Revision: https://reviews.llvm.org/D148381
2023-10-14 04:18:02 -07:00
alexfh
67b675ee55
Revert "[Clang] Implement the 'counted_by' attribute" (#68603)
This reverts commit 9a954c693573281407f6ee3f4eb1b16cc545033d, which
causes clang crashes when compiling with `-fsanitize=bounds`. See

9a954c6935 (commitcomment-129529574)
for details.
2023-10-09 20:53:48 +02:00
Krystian Stasiowski
3a3b84b180
[clang] remove ClassScopeFunctionSpecializationDecl (#66636)
This removes the `ClassScopeFunctionSpecializationDecl` `Decl` node, and
instead uses `DependentFunctionTemplateSpecializationInfo` to handle
such declarations. `DependentFunctionTemplateSpecializationInfo` is also
changed to store a `const ASTTemplateArgumentListInfo*` to be more in
line with `FunctionTemplateSpecializationInfo`.

This also changes `FunctionDecl::isFunctionTemplateSpecialization` to
return `true` for dependent specializations, and
`FunctionDecl::getTemplateSpecializationKind`/`FunctionDecl::getTemplateSpecializationKindForInstantiation`
to return `TSK_ExplicitSpecialization` for non-friend dependent
specializations (the same behavior as dependent class scope
`ClassTemplateSepcializationDecl` & `VarTemplateSepcializationDecl`).
2023-10-07 10:55:31 +04:00
Bill Wendling
9a954c6935 [Clang] Implement the 'counted_by' attribute
The 'counted_by' attribute is used on flexible array members. The
argument for the attribute is the name of the field member in the same
structure holding the count of elements in the flexible array. This
information can be used to improve the results of the array bound sanitizer
and the '__builtin_dynamic_object_size' builtin.

This example specifies the that the flexible array member 'array' has the
number of elements allocated for it in 'count':

  struct bar;
  struct foo {
    size_t count;
     /* ... */
    struct bar *array[] __attribute__((counted_by(count)));
  };

This establishes a relationship between 'array' and 'count', specifically
that 'p->array' must have *at least* 'p->count' number of elements available.
It's the user's responsibility to ensure that this relationship is maintained
through changes to the structure.

In the following, the allocated array erroneously has fewer elements than
what's specified by 'p->count'. This would result in an out-of-bounds access not
not being detected:

  struct foo *p;

  void foo_alloc(size_t count) {
    p = malloc(MAX(sizeof(struct foo),
                   offsetof(struct foo, array[0]) + count *
                       sizeof(struct bar *)));
    p->count = count + 42;
  }

The next example updates 'p->count', breaking the relationship requirement that
'p->array' must have at least 'p->count' number of elements available:

  struct foo *p;

  void foo_alloc(size_t count) {
    p = malloc(MAX(sizeof(struct foo),
                   offsetof(struct foo, array[0]) + count *
                       sizeof(struct bar *)));
    p->count = count + 42;
  }

  void use_foo(int index) {
    p->count += 42;
    p->array[index] = 0; /* The sanitizer cannot properly check this access */
  }

Reviewed By: nickdesaulniers, aaron.ballman

Differential Revision: https://reviews.llvm.org/D148381
2023-10-04 18:26:15 -07:00
Chuanqi Xu
52bc4b16cb [NFC] [C++20] [Modules] Refactor Sema::isModuleUnitOfCurrentTU into
Decl::isInAnotherModuleUnit

Refactor `Sema::isModuleUnitOfCurrentTU` to `Decl::isInAnotherModuleUnit`
to make code simpler a little bit. Note that although this patch
introduces a FIXME, this is an existing issue and this patch just tries
to describe it explicitly.
2023-05-23 10:52:22 +08:00
Chuanqi Xu
7f37066915 Revert "[NFC] [C++20] [Modules] Refactor Sema::isModuleUnitOfCurrentTU into"
This reverts commit f109b1016801e2b0dbee278f3c517057c0b1d441 as required
in
f109b10168 (commitcomment-113477829).
2023-05-16 10:47:53 +08:00
Chuanqi Xu
b6c7177145 [C++20] [Modules] Don't generate unused variables in other module units
even if its initializer has side effects

Close https://github.com/llvm/llvm-project/issues/61892

The variables whose initializer has side effects will be emitted even if
it is not used. But it shouldn't be true after we introduced modules.
The variables in other modules shouldn't be emitted if it is not used
even if its initializer has size effects.

Also this patch rename `Decl::isInCurrentModuleUnit` to
`Decl::isInAnotherModuleUnit` to make it closer to the semantics.
2023-05-10 17:41:58 +08:00
Chuanqi Xu
f109b10168 [NFC] [C++20] [Modules] Refactor Sema::isModuleUnitOfCurrentTU into
Decl::isInCurrentModuleUnit

Refactor `Sema::isModuleUnitOfCurrentTU` to `Decl::isInCurrentModuleUnit`
to make code simpler a little bit. Note that although this patch
introduces a FIXME, this is an existing issue and this patch just tries
to describe it explicitly.
2023-05-10 16:01:27 +08:00
Paulo Matos
8d0c889752 [clang][WebAssembly] Initial support for reference type funcref in clang
This is the funcref counterpart to 890146b. We introduce a new attribute
that marks a function pointer as a funcref. It also implements builtin
__builtin_wasm_ref_null_func(), that returns a null funcref value.

Differential Revision: https://reviews.llvm.org/D128440
2023-03-17 18:31:44 +01:00
Vassil Vassilev
dc4889357a [clang-repl] Support statements on global scope in incremental mode.
This patch teaches clang to parse statements on the global scope to allow:
```
./bin/clang-repl
clang-repl> int i = 12;
clang-repl> ++i;
clang-repl> extern "C" int printf(const char*,...);
clang-repl> printf("%d\n", i);
13
clang-repl> %quit
```

Generally, disambiguating between statements and declarations is a non-trivial
task for a C++ parser. The challenge is to allow both standard C++ to be
translated as if this patch does not exist and in the cases where the user typed
a statement to be executed as if it were in a function body.

Clang's Parser does pretty well in disambiguating between declarations and
expressions. We have added DisambiguatingWithExpression flag which allows us to
preserve the existing and optimized behavior where needed and implement the
extra rules for disambiguating. Only few cases require additional attention:
  * Constructors/destructors -- Parser::isConstructorDeclarator was used in to
    disambiguate between ctor-looking declarations and statements on the global
    scope(eg. `Ns::f()`).
  * The template keyword -- the template keyword can appear in both declarations
    and statements. This patch considers the template keyword to be a declaration
    starter which breaks a few cases in incremental mode which will be tackled
    later.
  * The inline (and similar) keyword -- looking at the first token in many cases
    allows us to classify what is a declaration.
  * Other language keywords and specifiers -- ObjC/ObjC++/OpenCL/OpenMP rely on
    pragmas or special tokens which will be handled in subsequent patches.

The patch conceptually models a "top-level" statement into a TopLevelStmtDecl.
The TopLevelStmtDecl is lowered into a void function with no arguments.
We attach this function to the global initializer list to execute the statement
blocks in the correct order.

Differential revision: https://reviews.llvm.org/D127284
2022-12-03 07:18:07 +00:00
Erich Keane
975740bf8d "Reapply "GH58368: Correct concept checking in a lambda defined in concept""
This reverts commit cecc9a92cfca71c1b6c2a35c5e302ab649496d11.

The problem ended up being how we were handling the lambda-context in
code generation: we were assuming any decl context here would be a
named-decl, but that isn't the case.  Instead, we just replace it with
the concept's owning context.

Differential Revision: https://reviews.llvm.org/D136451
2022-10-24 12:36:54 -07:00
Erich Keane
cecc9a92cf Revert "Reapply "GH58368: Correct concept checking in a lambda defined in concept"""
This reverts commit b876f6e2f28779211a829d7d4e841fe68885ae20.

Still getting build failures on PPC AIX that aren't obvious what is causing
them, so reverting while I try to figure this out.
2022-10-24 12:20:23 -07:00
Erich Keane
b876f6e2f2 Reapply "GH58368: Correct concept checking in a lambda defined in concept""
This reverts commit 52930162870fee52d0d9c07c5d66e5dce32b08e8.

Now with updating the ASTBitcodes to show that this AST is incompatible
from the last.
2022-10-24 11:46:54 -07:00
Erich Keane
5293016287 Revert "GH58368: Correct concept checking in a lambda defined in concept"
This reverts commit b7c922607c5ba93db8b893d4ba461052af8317b5.

This seems to cause some problems with some modules related things,
which makes me think I should have updated the version-major in
ast-bit-codes?  Going to revert to confirm this was a problem, then
change that and re-try a commit.
2022-10-24 10:21:22 -07:00
Erich Keane
b7c922607c GH58368: Correct concept checking in a lambda defined in concept
As that bug reports, the problem here is that the lambda's
'context-decl' was not set to the concept, and the lambda picked up
template arguments from the concept.  SO, we failed to get the correct
template arguments in SemaTemplateInstantiate.

However, a Concept Specialization is NOT a decl, its an expression, so
we weren't able to put the concept in the decl tree like we needed.
This patch introduces a ConceptSpecializationDecl, which is the smallest
type possible to use for this purpose, containing only the template
arguments.

The net memory impliciation of this is turning a
trailing-objects into a pointer to a type with trailing-objects,  so it
should be minor.

As future work, we may consider giving this type more responsibility, or
figuring out how to better merge duplicates, but as this is just a
template-argument collection at the moment, there isn't much value to
it.

Differential Revision: https://reviews.llvm.org/D136451
2022-10-24 06:32:18 -07:00
Erich Keane
6ebc3abd76 [NFC] Replace use of !isTranslationUnit && !isNamespace with !isFileContext
isFileContext is exactly equal to these two, so simplify the function.
2022-10-06 09:40:51 -07:00
Tom Honermann
4409a83c29 [clang] Correct handling of lambdas in lambda default arguments in dependent contexts.
Previously, a lambda expression in a dependent context with a default argument
containing an immediately invoked lambda expression would produce a closure
class object that, if invoked such that the default argument was used, resulted
in a compiler crash or one of the following assertion failures during code
generation. The failures occurred regardless of whether the lambda expressions
were dependent.

  clang/lib/CodeGen/CGCall.cpp:
  Assertion `(isGenericMethod || Ty->isVariablyModifiedType() || Ty.getNonReferenceType()->isObjCRetainableType() || getContext() .getCanonicalType(Ty.getNonReferenceType()) .getTypePtr() == getContext().getCanonicalType((*Arg)->getType()).getTypePtr()) && "type mismatch in call argument!"' failed.

  clang/lib/AST/Decl.cpp:
  Assertion `!Init->isValueDependent()' failed.

Default arguments in declarations in local context are instantiated along with
their enclosing function or variable template (since such declarations can't
be explicitly specialized). Previously, such instantiations were performed at
the same time that their associated parameters were instantiated. However, that
approach fails in cases like the following in which the context for the inner
lambda is the outer lambda, but construction of the outer lambda is dependent
on the parameters of the inner lambda. This change resolves this dependency by
delyaing instantiation of default arguments in local contexts until after
construction of the enclosing context.
  template <typename T>
  auto f() {
    return [](T = []{ return T{}; }()) { return 0; };
  }

Refactoring included with this change results in the same code now being used
to instantiate default arguments that appear in local context and those that
are only instantiated when used at a call site; previously, such code was
duplicated and out of sync.

Fixes https://github.com/llvm/llvm-project/issues/49178

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D133500
2022-10-04 09:04:54 -07:00
Tom Honermann
4247cdb568 [clang]: Add DeclContext::dumpAsDecl().
This change enables a declaration to be conveniently displayed within
a debugger when only a pointer to its DeclContext is available. For example,
in gdb:
  (gdb) p Ctx
  $1 = (const clang::DeclContext *) 0x14c1a580
  (gdb) p Ctx->dumpAsDecl()
  ClassTemplateSpecializationDecl 0x14c1a540 <t.cpp:1:1, line:7:1> line:2:8 struct ct
  `-TemplateArgument type 'int'
    `-BuiltinType 0x14bac420 'int'
  $2 = void

In the event that the pointed to DeclContext is invalid (that it has an
invalid DeclKind as a result of a dangling pointer, memory corruption, etc...)
it is not possible to dump its associated declaration. In this case, the
DeclContext will be reported as invalid. For example, in gdb:
  (gdb) p Ctx->dumpAsDecl()
  DeclContext 0x14c1a580 <unrecognized Decl kind 127>
  $3 = void
2022-10-03 17:25:44 -04:00
Erich Keane
939a3d22e2 [Concepts] Fix Concepts on generic lambda in a VarTemplateSpecDecl
As fallout of the Deferred Concept Instantiation patch (babdef27c5), we
got a number of reports of a regression, where we asserted when
instantiating a constraint on a generic lambda inside of a variable
template. See: https://github.com/llvm/llvm-project/issues/57958

The problem was that getTemplateInstantiationArgs function only walked
up declaration contexts, and missed that this is not necessarily the
case with a lambda (which can ALSO be in a separate context).

This patch refactors the getTemplateInstantiationArgs function in a way
that is hopefully more readable, and fixes the problem with the concepts
on a generic lambda.

Differential Revision: https://reviews.llvm.org/D134874
2022-10-03 12:44:21 -07:00
Xiang Li
782ac2182c [HLSL] Support cbuffer/tbuffer for hlsl.
This is first part for support cbuffer/tbuffer.

The format for cbuffer/tbuffer is
BufferType [Name] [: register(b#)] { VariableDeclaration [: packoffset(c#.xyzw)]; ... };

More details at https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-constants

New keyword 'cbuffer' and 'tbuffer' are added.
New AST node HLSLBufferDecl is added.
Build AST for simple cbuffer/tbuffer without attribute support.

The special thing is variables declared inside cbuffer is exposed into global scope.
So isTransparentContext should return true for HLSLBuffer.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D129883
2022-09-21 10:07:43 -07:00
Michael Buch
e456d2ba8b [clang][ASTImporter] DeclContext::localUncachedLookup: Continue lookup into decl chain when regular lookup fails
The uncached lookup is mainly used in the ASTImporter/LLDB code-path
where we're not allowed to load from external storage. When importing
a FieldDecl with a DeclContext that had no external visible storage
(but came from a Clang module or PCH) the above call to `lookup(Name)`
the regular `DeclContext::lookup` fails because:
1. `DeclContext::buildLookup` doesn't set `LookupPtr` for decls
   that came from a module
2. LLDB doesn't use the `SharedImporterState`

In such a case we would never continue with the "slow" path of iterating
through the decl chain on the DeclContext. In some cases this means that
ASTNodeImporter::VisitFieldDecl ends up importing a decl into the
DeclContext a second time.

The patch removes the short-circuit in the case where we don't find
any decls via the regular lookup.

**Tests**

* Un-skip the failing LLDB API tests

Differential Revision: https://reviews.llvm.org/D133945
2022-09-16 12:38:50 -04:00
Chuanqi Xu
0bc993edf4 [AST] [Modules] Introduce Decl::getNonTransparentDeclContext to handle exported friends
Closing https://github.com/llvm/llvm-project/issues/56826.

The root cause for pr56826 is: when we collect the template args for the
friend, we need to judge if the friend lives in file context. However,
if the friend lives in ExportDecl lexically, the judgement here is
invalid.

The solution is easy. We should judge the non transparent context and
the ExportDecl is transparent context. So the solution should be good.

A main concern may be the patch doesn't handle all the places of the
same defect. I think it might not be bad since the patch itself should
be innocent.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D131651
2022-08-12 11:50:35 +08:00
Erich Keane
70c62f4cad [NFC] give getParentFunctionOrMethod a 'Lexical' parameter
Split up from the deferred concepts implementation, this function is
useful for determining the containing function of a different function.
However, in some cases it is valuable to instead get the lexical parent.
This adds a parameter to the existing function to allow a 'Lexical'
parameter to instead select the lexical parent.
2022-07-22 12:52:26 -07:00
Erich Keane
258c3aee54 Revert "Re-apply "Deferred Concept Instantiation Implementation"""
This reverts commit befa8cf087dbb8159a4d9dc8fa4d6748d6d5049a.

Apparently this breaks some libc++ builds with an apparent assertion,
 so I'm looking into that .
2022-07-01 11:20:16 -07:00
Erich Keane
befa8cf087 Re-apply "Deferred Concept Instantiation Implementation""
This reverts commit d4d47e574ecae562ab32f8ac7fa3f4d424bb6574.

This fixes the lldb crash that was observed by ensuring that our
friend-'template contains reference to' TreeTransform properly handles a
TemplateDecl.
2022-07-01 06:51:38 -07:00