aaron.ballman added a comment.
In D150528#4349711 <https://reviews.llvm.org/D150528#4349711>, @yronglin wrote:
> Sorry for the late reply and thanks for your tips! @aaron.ballman I followed
> your advice to update this patch, and below AST generated by clang:
>
> class alignas(void *) Foo {};
> _Alignas(void*) char align32array[128];
>
> template <typename T> class alignas(T) Bar {};
> template <unsigned N> class alignas(N) FooBar {};
>
> int main() {
> Bar<int> bar;
> FooBar<4> fooBar;
> return 0;
> }
>
>
>
> ➜ test ../rel/bin/clang++ -cc1 -triple x86_64-pc-linux -ast-dump
> ./alignas.cpp -std=c++11
> alignas _Alignas alignas alignasTranslationUnitDecl 0x14b043208 <<invalid
> sloc>> <invalid sloc>
> |-TypedefDecl 0x14b043a70 <<invalid sloc>> <invalid sloc> implicit
> __int128_t '__int128'
> | `-BuiltinType 0x14b0437d0 '__int128'
> |-TypedefDecl 0x14b043ae0 <<invalid sloc>> <invalid sloc> implicit
> __uint128_t 'unsigned __int128'
> | `-BuiltinType 0x14b0437f0 'unsigned __int128'
> |-TypedefDecl 0x14b043e58 <<invalid sloc>> <invalid sloc> implicit
> __NSConstantString '__NSConstantString_tag'
> | `-RecordType 0x14b043bd0 '__NSConstantString_tag'
> | `-CXXRecord 0x14b043b38 '__NSConstantString_tag'
> |-TypedefDecl 0x14b043ef0 <<invalid sloc>> <invalid sloc> implicit
> __builtin_ms_va_list 'char *'
> | `-PointerType 0x14b043eb0 'char *'
> | `-BuiltinType 0x14b0432b0 'char'
> |-TypedefDecl 0x14b087858 <<invalid sloc>> <invalid sloc> implicit
> __builtin_va_list '__va_list_tag[1]'
> | `-ConstantArrayType 0x14b087800 '__va_list_tag[1]' 1
> | `-RecordType 0x14b043fe0 '__va_list_tag'
> | `-CXXRecord 0x14b043f48 '__va_list_tag'
> |-CXXRecordDecl 0x14b0878e8 <./alignas.cpp:1:1, col:28> col:23 class Foo
> definition
> | |-DefinitionData pass_in_registers empty aggregate standard_layout
> trivially_copyable pod trivial literal has_constexpr_non_copy_move_ctor
> can_const_default_init
> | | |-DefaultConstructor exists trivial constexpr needs_implicit
> defaulted_is_constexpr
> | | |-CopyConstructor simple trivial has_const_param needs_implicit
> implicit_has_const_param
> | | |-MoveConstructor exists simple trivial needs_implicit
> | | |-CopyAssignment simple trivial has_const_param needs_implicit
> implicit_has_const_param
> | | |-MoveAssignment exists simple trivial needs_implicit
> | | `-Destructor simple irrelevant trivial needs_implicit
> | |-AlignedAttr 0x14b087a08 <col:7> alignas 'void *'
> | `-CXXRecordDecl 0x14b087a68 <col:1, col:23> col:23 implicit class Foo
> |-VarDecl 0x14b087be8 <line:2:1, col:38> col:22 align32array 'char[128]'
> | `-AlignedAttr 0x14b087c50 <col:1> _Alignas 'void *'
> |-ClassTemplateDecl 0x14b087e80 <line:4:1, col:45> col:40 Bar
> | |-TemplateTypeParmDecl 0x14b087cf8 <col:11, col:20> col:20 referenced
> typename depth 0 index 0 T
> | |-CXXRecordDecl 0x14b087df0 <col:23, col:45> col:40 class Bar definition
> | | |-DefinitionData empty aggregate standard_layout trivially_copyable pod
> trivial literal has_constexpr_non_copy_move_ctor can_const_default_init
> | | | |-DefaultConstructor exists trivial constexpr needs_implicit
> defaulted_is_constexpr
> | | | |-CopyConstructor simple trivial has_const_param needs_implicit
> implicit_has_const_param
> | | | |-MoveConstructor exists simple trivial needs_implicit
> | | | |-CopyAssignment simple trivial has_const_param needs_implicit
> implicit_has_const_param
> | | | |-MoveAssignment exists simple trivial needs_implicit
> | | | `-Destructor simple irrelevant trivial needs_implicit
> | | |-AlignedAttr 0x14b0880d0 <col:29> alignas 'T'
> | | `-CXXRecordDecl 0x14b088130 <col:23, col:40> col:40 implicit class Bar
> | `-ClassTemplateSpecializationDecl 0x14b09e200 <col:1, col:45> col:40
> class Bar definition
> | |-DefinitionData pass_in_registers empty aggregate standard_layout
> trivially_copyable pod trivial literal has_constexpr_non_copy_move_ctor
> can_const_default_init
> | | |-DefaultConstructor exists trivial constexpr defaulted_is_constexpr
> | | |-CopyConstructor simple trivial has_const_param
> implicit_has_const_param
> | | |-MoveConstructor exists simple trivial
> | | |-CopyAssignment simple trivial has_const_param needs_implicit
> implicit_has_const_param
> | | |-MoveAssignment exists simple trivial needs_implicit
> | | `-Destructor simple irrelevant trivial needs_implicit
> | |-TemplateArgument type 'int'
> | | `-BuiltinType 0x14b043310 'int'
> | |-AlignedAttr 0x14b09e458 <col:29> alignas 'int':'int'
> | |-CXXRecordDecl 0x14b09e520 <col:23, col:40> col:40 implicit class Bar
> | |-CXXConstructorDecl 0x14b09e5e0 <col:40> col:40 implicit used
> constexpr Bar 'void () noexcept' inline default trivial
> | | `-CompoundStmt 0x14b09eb48 <col:40>
> | |-CXXConstructorDecl 0x14b09e778 <col:40> col:40 implicit constexpr Bar
> 'void (const Bar<int> &)' inline default trivial noexcept-unevaluated
> 0x14b09e778
> | | `-ParmVarDecl 0x14b09e898 <col:40> col:40 'const Bar<int> &'
> | `-CXXConstructorDecl 0x14b09e978 <col:40> col:40 implicit constexpr Bar
> 'void (Bar<int> &&)' inline default trivial noexcept-unevaluated 0x14b09e978
> | `-ParmVarDecl 0x14b09ea98 <col:40> col:40 'Bar<int> &&'
> |-ClassTemplateDecl 0x14b088310 <line:5:1, col:48> col:40 FooBar
> | |-NonTypeTemplateParmDecl 0x14b0881f0 <col:11, col:20> col:20 referenced
> 'unsigned int' depth 0 index 0 N
> | |-CXXRecordDecl 0x14b088280 <col:23, col:48> col:40 class FooBar
> definition
> | | |-DefinitionData empty aggregate standard_layout trivially_copyable pod
> trivial literal has_constexpr_non_copy_move_ctor can_const_default_init
> | | | |-DefaultConstructor exists trivial constexpr needs_implicit
> defaulted_is_constexpr
> | | | |-CopyConstructor simple trivial has_const_param needs_implicit
> implicit_has_const_param
> | | | |-MoveConstructor exists simple trivial needs_implicit
> | | | |-CopyAssignment simple trivial has_const_param needs_implicit
> implicit_has_const_param
> | | | |-MoveAssignment exists simple trivial needs_implicit
> | | | `-Destructor simple irrelevant trivial needs_implicit
> | | |-AlignedAttr 0x14b088580 <col:29> alignas
> | | | `-DeclRefExpr 0x14b088260 <col:37> 'unsigned int' NonTypeTemplateParm
> 0x14b0881f0 'N' 'unsigned int'
> | | `-CXXRecordDecl 0x14b0885e0 <col:23, col:40> col:40 implicit class
> FooBar
> | `-ClassTemplateSpecializationDecl 0x14b09ed10 <col:1, col:48> col:40
> class FooBar definition
> | |-DefinitionData pass_in_registers empty aggregate standard_layout
> trivially_copyable pod trivial literal has_constexpr_non_copy_move_ctor
> can_const_default_init
> | | |-DefaultConstructor exists trivial constexpr defaulted_is_constexpr
> | | |-CopyConstructor simple trivial has_const_param
> implicit_has_const_param
> | | |-MoveConstructor exists simple trivial
> | | |-CopyAssignment simple trivial has_const_param needs_implicit
> implicit_has_const_param
> | | |-MoveAssignment exists simple trivial needs_implicit
> | | `-Destructor simple irrelevant trivial needs_implicit
> | |-TemplateArgument integral 4
> | |-AlignedAttr 0x14b09ef90 <col:29> alignas
> | | `-ConstantExpr 0x14b09ef70 <col:37> 'unsigned int'
> | | |-value: Int 4
> | | `-SubstNonTypeTemplateParmExpr 0x14b09ef48 <col:37> 'unsigned int'
> | | |-NonTypeTemplateParmDecl 0x14b0881f0 <col:11, col:20> col:20
> referenced 'unsigned int' depth 0 index 0 N
> | | `-IntegerLiteral 0x14b09ef28 <col:37> 'unsigned int' 4
> | |-CXXRecordDecl 0x14b09f058 <col:23, col:40> col:40 implicit class
> FooBar
> | |-CXXConstructorDecl 0x14980fc00 <col:40> col:40 implicit used
> constexpr FooBar 'void () noexcept' inline default trivial
> | | `-CompoundStmt 0x149810108 <col:40>
> | |-CXXConstructorDecl 0x14980fd68 <col:40> col:40 implicit constexpr
> FooBar 'void (const FooBar<4> &)' inline default trivial noexcept-unevaluated
> 0x14980fd68
> | | `-ParmVarDecl 0x14980fe88 <col:40> col:40 'const FooBar<4> &'
> | `-CXXConstructorDecl 0x14980ff68 <col:40> col:40 implicit constexpr
> FooBar 'void (FooBar<4> &&)' inline default trivial noexcept-unevaluated
> 0x14980ff68
> | `-ParmVarDecl 0x149810088 <col:40> col:40 'FooBar<4> &&'
> `-FunctionDecl 0x14b0886e0 <line:7:1, line:11:1> line:7:5 main 'int ()'
> `-CompoundStmt 0x1498101e8 <col:12, line:11:1>
> |-DeclStmt 0x14b09eca0 <line:8:3, col:15>
> | `-VarDecl 0x14b09e3b0 <col:3, col:12> col:12 bar
> 'Bar<int>':'Bar<int>' callinit
> | `-CXXConstructExpr 0x14b09ec78 <col:12> 'Bar<int>':'Bar<int>' 'void
> () noexcept'
> |-DeclStmt 0x1498101a0 <line:9:3, col:19>
> | `-VarDecl 0x14b09eec0 <col:3, col:13> col:13 fooBar
> 'FooBar<4>':'FooBar<4>' callinit
> | `-CXXConstructExpr 0x149810178 <col:13> 'FooBar<4>':'FooBar<4>'
> 'void () noexcept'
> `-ReturnStmt 0x1498101d8 <line:10:3, col:10>
> `-IntegerLiteral 0x1498101b8 <col:10> 'int' 0
>
> This AST dose not have a `UnaryExprOrTypeTraitExpr` in `alignas`, What do you
> think?
That is exactly what I would hope the AST would look like -- it's great! The
next step would be to add CodeGen tests to validate that the correct alignment
is emitted to LLVM IR with the type-base form.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D150528/new/
https://reviews.llvm.org/D150528
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
