On Mon, Oct 11, 2021 at 2:46 PM Richard Smith <rich...@metafoo.co.uk> wrote:
> On Wed, 15 Sept 2021 at 13:52, David Blaikie <dblai...@gmail.com> wrote: > >> On Tue, Sep 14, 2021 at 10:04 AM Richard Smith <rich...@metafoo.co.uk> >> wrote: >> >>> On Mon, 13 Sept 2021 at 19:24, David Blaikie via cfe-commits < >>> cfe-commits@lists.llvm.org> wrote: >>> >>>> >>>> Author: David Blaikie >>>> Date: 2021-09-13T19:17:05-07:00 >>>> New Revision: 2bd84938470bf2e337801faafb8a67710f46429d >>>> >>>> URL: >>>> https://github.com/llvm/llvm-project/commit/2bd84938470bf2e337801faafb8a67710f46429d >>>> DIFF: >>>> https://github.com/llvm/llvm-project/commit/2bd84938470bf2e337801faafb8a67710f46429d.diff >>>> >>>> LOG: Improve type printing of const arrays to normalize array-of-const >>>> and const-array >>>> >>>> Since these map to the same effective type - render them the same/in the >>>> more legible way (const x[n]). >>>> >>> >>> Nice! >>> >>> >>>> Added: >>>> >>>> >>>> Modified: >>>> clang/lib/AST/TypePrinter.cpp >>>> clang/test/ARCMT/cxx-checking.mm >>>> clang/test/AST/ast-dump-APValue-arithmetic.cpp >>>> clang/test/AST/ast-dump-APValue-array.cpp >>>> clang/test/CXX/basic/basic.types/p10.cpp >>>> clang/test/Sema/assign.c >>>> clang/test/Sema/typedef-retain.c >>>> clang/test/SemaCXX/reinterpret-cast.cpp >>>> clang/test/SemaCXX/static-assert-cxx17.cpp >>>> >>>> Removed: >>>> >>>> >>>> >>>> >>>> ################################################################################ >>>> diff --git a/clang/lib/AST/TypePrinter.cpp >>>> b/clang/lib/AST/TypePrinter.cpp >>>> index aef1e4f3f4953..251db97c7db08 100644 >>>> --- a/clang/lib/AST/TypePrinter.cpp >>>> +++ b/clang/lib/AST/TypePrinter.cpp >>>> @@ -200,11 +200,12 @@ bool TypePrinter::canPrefixQualifiers(const Type >>>> *T, >>>> // type expands to a simple string. >>>> bool CanPrefixQualifiers = false; >>>> NeedARCStrongQualifier = false; >>>> - Type::TypeClass TC = T->getTypeClass(); >>>> + const Type *UnderlyingType = T; >>>> if (const auto *AT = dyn_cast<AutoType>(T)) >>>> - TC = AT->desugar()->getTypeClass(); >>>> + UnderlyingType = AT->desugar().getTypePtr(); >>>> if (const auto *Subst = dyn_cast<SubstTemplateTypeParmType>(T)) >>>> - TC = Subst->getReplacementType()->getTypeClass(); >>>> + UnderlyingType = Subst->getReplacementType().getTypePtr(); >>>> + Type::TypeClass TC = UnderlyingType->getTypeClass(); >>>> >>>> switch (TC) { >>>> case Type::Auto: >>>> @@ -243,6 +244,9 @@ bool TypePrinter::canPrefixQualifiers(const Type *T, >>>> >>>> case Type::ConstantArray: >>>> case Type::IncompleteArray: >>>> + return canPrefixQualifiers( >>>> + >>>> cast<ArrayType>(UnderlyingType)->getElementType().getTypePtr(), >>>> + NeedARCStrongQualifier); >>>> case Type::VariableArray: >>>> case Type::DependentSizedArray: >>>> >>> >>> Can we give these two cases the same treatment? >>> >> >> Handled the DependentSizedArray in >> https://github.com/llvm/llvm-project/commit/40acc0adad59ac39e9a7a02fcd93161298500c00 >> >> But per the comment in that commit I wasn't able to reproduce the problem >> with a variable array - though we could include it in the handling on >> principle/for consistency, even without a test/etc. Perhaps there's a way >> to test/provoke the behavior you might know that I couldn't figure out? >> >> Details from the commit: >> >> The VariableArray case I couldn't figure out how to test/provoke - >> you >> >> can't write/form a variable array in any context other than a local >> >> variable that I know of, and in that case `const int x[n]` is the >> >> normalized form already (array-of-const) and you can't use typedefs >> >> (since you can't typedef int[n] with variable 'n') to force the >> >> const-array AST that would produce the undesirable type printing "int >> >> const [n]". >> > > C has a fairly surprising rule here -- you actually can define a VLA type > in a local typedef. For example, > > void f(int n) { > typedef int arr[n]; > const arr x; > } > > ... is valid in C. In C++ mode, this produces: > > <source>:3:15: error: default initialization of an object of const type > 'const arr' (aka 'int const[n]') > > (note, 'int const[n]' not 'const int[n]'). > Oh, right, good to understand! Yep, fixed and tested with this: 39093279f2ede4af9048b89d048d7fe9182a50f8 Huh, funny diagnostic experience aside here: https://godbolt.org/z/W46b3qc49 void f(int i) { typedef int x[i]; const x y = {}; } <source>:2:19: error: variable-sized object may not be initialized typedef int x[i]; ^ With no pointer/note/etc to the 'y' variable - the typedef and variable could be quite far apart. The diagnostic would be hard to read/understand. > Oh, also - another quirk of array type printing that I'd be up for >> addressing if you've got an opinion on it: >> >> "int [n]" is printed with a space between the "int" and array. >> "int *const[n]" is printed without a space before the array (though both >> have a space after "int") >> >> ClangFormat formats these as "int[n]" and "int *const[n]" - with * >> left/right depending on ClangFormat's heuristics/configuration. >> >> Reckon we should remove the space in "int[n]"? >> > > I think we should make it consistent, one way or the other. Beyond that, > the decision seems somewhat arbitrary, but following clang-format seems > reasonable to me. I certainly would expect `int *[n]` rather than `int * > [n]`, which similarly suggests omitting the space here. > It looks like the cause is this: https://github.com/llvm/llvm-project/blob/40acc0adad59ac39e9a7a02fcd93161298500c00/clang/lib/AST/TypePrinter.cpp#L508 But there seem to be a lot of similar code with NonEmptyPH that presumably has similar effects - any idea why? Cases include: PointerBefore (changes 'char *' to 'char*' (though 'char *[N]' keeps the space before the '*') PointerAfter (ah, seems to be related to the closing ")" in "void (*const)" - so I would've /thought/ the leading "(" would be disabled by removing the NonEmptyPH in PointerBefore... but apparently not? So I'm not sure why the asymmetry here - might be more related to the PrevPHIsEmpty in printBefore(Type*, Qualifiers, raw_ostream)) BlockPointerBefore BlockPointerAfter LValueReferenceBefore LValueReferenceAfter RValueReferenceBefore RValueReferenceAfter MemberPointerBefore MemberPointerAfter ConstantArrayBefore IncompleteArrayBefore VariableArrayBefore DependentSizedArrayBefore FunctionProtoAfter FunctionNoProtoAfter Still playing around with some other cases here to better understand. I guess some stuff uses NonEmptyPlaceHolder for when, for instance, the qualifier has to go on the right ("void *const") so when printing the underlying pointer type, it has a non-empty place holder (the const) but the const itself has an empty placeholder (no variable name), etc. I'll try just removing the array ones, see what that looks like. NeedARCStrongQualifier = true; >>> >>> >>>> diff --git a/clang/test/ARCMT/cxx-checking.mm b/clang/test/ARCMT/ >>>> cxx-checking.mm >>>> index 952f3cdcbb79c..d6441def09b40 100644 >>>> --- a/clang/test/ARCMT/cxx-checking.mm >>>> +++ b/clang/test/ARCMT/cxx-checking.mm >>>> @@ -80,7 +80,7 @@ >>>> >>>> struct FlexibleArrayMember0 { >>>> int length; >>>> - id array[]; // expected-error{{flexible array member 'array' of type >>>> 'id __strong[]' with non-trivial destruction}} >>>> + id array[]; // expected-error{{flexible array member 'array' of type >>>> '__strong id []' with non-trivial destruction}} >>>> }; >>>> >>>> struct FlexibleArrayMember1 { >>>> >>>> diff --git a/clang/test/AST/ast-dump-APValue-arithmetic.cpp >>>> b/clang/test/AST/ast-dump-APValue-arithmetic.cpp >>>> index 835d8c8108346..e51c1cee04cfe 100644 >>>> --- a/clang/test/AST/ast-dump-APValue-arithmetic.cpp >>>> +++ b/clang/test/AST/ast-dump-APValue-arithmetic.cpp >>>> @@ -36,13 +36,13 @@ void Test() { >>>> // CHECK-NEXT: | |-value: ComplexFloat 3.141500e+00 + >>>> 4.200000e+01i >>>> >>>> constexpr _Complex int ArrayOfComplexInt[10] = {ComplexInt, >>>> ComplexInt, ComplexInt, ComplexInt}; >>>> - // CHECK: | `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} >>>> ArrayOfComplexInt '_Complex int const[10]' constexpr cinit >>>> + // CHECK: | `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} >>>> ArrayOfComplexInt 'const _Complex int [10]' constexpr cinit >>>> // CHECK-NEXT: | |-value: Array size=10 >>>> // CHECK-NEXT: | | |-elements: ComplexInt 42 + 24i, ComplexInt 42 >>>> + 24i, ComplexInt 42 + 24i, ComplexInt 42 + 24i >>>> // CHECK-NEXT: | | `-filler: 6 x ComplexInt 0 + 0i >>>> >>>> constexpr _Complex float ArrayOfComplexFloat[10] = {ComplexFloat, >>>> ComplexFloat, ComplexInt, ComplexInt}; >>>> - // CHECK: `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} >>>> ArrayOfComplexFloat '_Complex float const[10]' constexpr cinit >>>> + // CHECK: `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} >>>> ArrayOfComplexFloat 'const _Complex float [10]' constexpr cinit >>>> // CHECK-NEXT: |-value: Array size=10 >>>> // CHECK-NEXT: | |-elements: ComplexFloat 3.141500e+00 + >>>> 4.200000e+01i, ComplexFloat 3.141500e+00 + 4.200000e+01i, ComplexFloat >>>> 4.200000e+01 + 2.400000e+01i, ComplexFloat 4.200000e+01 + 2.400000e+01i >>>> // CHECK-NEXT: | `-filler: 6 x ComplexFloat 0.000000e+00 + >>>> 0.000000e+00i >>>> >>>> diff --git a/clang/test/AST/ast-dump-APValue-array.cpp >>>> b/clang/test/AST/ast-dump-APValue-array.cpp >>>> index f9b38ec332a5b..72e519208ac56 100644 >>>> --- a/clang/test/AST/ast-dump-APValue-array.cpp >>>> +++ b/clang/test/AST/ast-dump-APValue-array.cpp >>>> @@ -43,7 +43,7 @@ void Test() { >>>> constexpr float arr_f[3][5] = { >>>> {1, 2, 3, 4, 5}, >>>> }; >>>> - // CHECK: | `-VarDecl {{.*}} <line:{{.*}}, line:{{.*}}> line:{{.*}} >>>> arr_f 'float const[3][5]' constexpr cinit >>>> + // CHECK: | `-VarDecl {{.*}} <line:{{.*}}, line:{{.*}}> line:{{.*}} >>>> arr_f 'const float [3][5]' constexpr cinit >>>> // CHECK-NEXT: | |-value: Array size=3 >>>> // CHECK-NEXT: | | |-element: Array size=5 >>>> // CHECK-NEXT: | | | |-elements: Float 1.000000e+00, Float >>>> 2.000000e+00, Float 3.000000e+00, Float 4.000000e+00 >>>> @@ -52,7 +52,7 @@ void Test() { >>>> // CHECK-NEXT: | | `-filler: 5 x Float 0.000000e+00 >>>> >>>> constexpr S0 arr_s0[2] = {{1, 2}, {3, 4}}; >>>> - // CHECK: | `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} >>>> arr_s0 'S0 const[2]' constexpr cinit >>>> + // CHECK: | `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} >>>> arr_s0 'const S0 [2]' constexpr cinit >>>> // CHECK-NEXT: | |-value: Array size=2 >>>> // CHECK-NEXT: | | |-element: Struct >>>> // CHECK-NEXT: | | | `-field: Array size=2 >>>> @@ -62,12 +62,12 @@ void Test() { >>>> // CHECK-NEXT: | | `-elements: Int 3, Int 4 >>>> >>>> constexpr U0 arr_u0[2] = {{.i = 42}, {.f = 3.1415f}}; >>>> - // CHECK: | `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} >>>> arr_u0 'U0 const[2]' constexpr cinit >>>> + // CHECK: | `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} >>>> arr_u0 'const U0 [2]' constexpr cinit >>>> // CHECK-NEXT: | |-value: Array size=2 >>>> // CHECK-NEXT: | | `-elements: Union .i Int 42, Union .f Float >>>> 3.141500e+00 >>>> >>>> constexpr S1 arr_s1[2] = {}; >>>> - // CHECK: `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} >>>> arr_s1 'S1 const[2]' constexpr cinit >>>> + // CHECK: `-VarDecl {{.*}} <col:{{.*}}, col:{{.*}}> col:{{.*}} >>>> arr_s1 'const S1 [2]' constexpr cinit >>>> // CHECK-NEXT: |-value: Array size=2 >>>> // CHECK-NEXT: | |-element: Struct >>>> // CHECK-NEXT: | | |-field: Struct >>>> >>>> diff --git a/clang/test/CXX/basic/basic.types/p10.cpp >>>> b/clang/test/CXX/basic/basic.types/p10.cpp >>>> index aac07c76bed2e..eae0c6513ac24 100644 >>>> --- a/clang/test/CXX/basic/basic.types/p10.cpp >>>> +++ b/clang/test/CXX/basic/basic.types/p10.cpp >>>> @@ -32,7 +32,7 @@ struct Incomplete; // expected-note 2{{forward >>>> declaration of 'Incomplete'}} >>>> template<class T> struct ClassTemp {}; >>>> >>>> constexpr Incomplete incomplete = {}; // expected-error {{constexpr >>>> variable cannot have non-literal type 'const Incomplete'}} expected-note >>>> {{incomplete type 'const Incomplete' is not a literal type}} >>>> -constexpr Incomplete incomplete2[] = {}; // expected-error {{constexpr >>>> variable cannot have non-literal type 'Incomplete const[]'}} expected-note >>>> {{incomplete type 'Incomplete const[]' is not a literal type}} >>>> +constexpr Incomplete incomplete2[] = {}; // expected-error {{constexpr >>>> variable cannot have non-literal type 'const Incomplete []'}} expected-note >>>> {{incomplete type 'const Incomplete []' is not a literal type}} >>>> constexpr ClassTemp<int> classtemplate = {}; >>>> constexpr ClassTemp<int> classtemplate2[] = {}; >>>> >>>> >>>> diff --git a/clang/test/Sema/assign.c b/clang/test/Sema/assign.c >>>> index 3edd5d4feaf2e..d65f9bf26547e 100644 >>>> --- a/clang/test/Sema/assign.c >>>> +++ b/clang/test/Sema/assign.c >>>> @@ -13,7 +13,7 @@ typedef int arr[10]; >>>> void test3() { >>>> const arr b; // expected-note {{variable 'b' declared const >>>> here}} >>>> const int b2[10]; // expected-note {{variable 'b2' declared const >>>> here}} >>>> - b[4] = 1; // expected-error {{cannot assign to variable 'b' >>>> with const-qualified type 'const arr' (aka 'int const[10]')}} >>>> + b[4] = 1; // expected-error {{cannot assign to variable 'b' >>>> with const-qualified type 'const arr' (aka 'const int [10]')}} >>>> b2[4] = 1; // expected-error {{cannot assign to variable 'b2' >>>> with const-qualified type 'const int [10]'}} >>>> } >>>> >>>> >>>> diff --git a/clang/test/Sema/typedef-retain.c >>>> b/clang/test/Sema/typedef-retain.c >>>> index 70e2abc1da5b8..d4358bce5ee5b 100644 >>>> --- a/clang/test/Sema/typedef-retain.c >>>> +++ b/clang/test/Sema/typedef-retain.c >>>> @@ -17,7 +17,7 @@ typedef int a[5]; >>>> void test3() { >>>> typedef const a b; >>>> b r; // expected-note {{variable 'r' declared const here}} >>>> - r[0] = 10; // expected-error {{cannot assign to variable 'r' with >>>> const-qualified type 'b' (aka 'int const[5]')}} >>>> + r[0] = 10; // expected-error {{cannot assign to variable 'r' with >>>> const-qualified type 'b' (aka 'const int [5]')}} >>>> } >>>> >>>> int test4(const a y) { >>>> >>>> diff --git a/clang/test/SemaCXX/reinterpret-cast.cpp >>>> b/clang/test/SemaCXX/reinterpret-cast.cpp >>>> index 6a4bc91665448..f427af1efbafc 100644 >>>> --- a/clang/test/SemaCXX/reinterpret-cast.cpp >>>> +++ b/clang/test/SemaCXX/reinterpret-cast.cpp >>>> @@ -132,7 +132,7 @@ void const_arrays() { >>>> const STRING *s; >>>> const char *c; >>>> >>>> - (void)reinterpret_cast<char *>(s); // expected-error >>>> {{reinterpret_cast from 'const STRING *' (aka 'char const (*)[10]') to >>>> 'char *' casts away qualifiers}} >>>> + (void)reinterpret_cast<char *>(s); // expected-error >>>> {{reinterpret_cast from 'const STRING *' (aka 'const char (*)[10]') to >>>> 'char *' casts away qualifiers}} >>>> (void)reinterpret_cast<const STRING *>(c); >>>> } >>>> >>>> >>>> diff --git a/clang/test/SemaCXX/static-assert-cxx17.cpp >>>> b/clang/test/SemaCXX/static-assert-cxx17.cpp >>>> index fe02f8f29965f..d5601839bdd3e 100644 >>>> --- a/clang/test/SemaCXX/static-assert-cxx17.cpp >>>> +++ b/clang/test/SemaCXX/static-assert-cxx17.cpp >>>> @@ -94,7 +94,7 @@ void foo6() { >>>> static_assert(static_cast<const X<typename T::T> *>(nullptr)); >>>> // expected-error@-1{{static_assert failed due to requirement >>>> 'static_cast<const X<int> *>(nullptr)'}} >>>> static_assert((const X<typename T::T>[]){} == nullptr); >>>> - // expected-error@-1{{static_assert failed due to requirement >>>> '(X<int> const[0]){} == nullptr'}} >>>> + // expected-error@-1{{static_assert failed due to requirement >>>> '(const X<int> [0]){} == nullptr'}} >>>> static_assert(sizeof(X<decltype(X<typename T::T>().X<typename >>>> T::T>::~X())>) == 0); >>>> // expected-error@-1{{static_assert failed due to requirement >>>> 'sizeof(X<void>) == 0'}} >>>> static_assert(constexpr_return_false<typename T::T, typename >>>> T::U>()); >>>> >>>> >>>> >>>> _______________________________________________ >>>> cfe-commits mailing list >>>> cfe-commits@lists.llvm.org >>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >>>> >>>
_______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
