[clang] eec9431 - [Clang] Added explanation why a is trivial copyable evaluated to false. (#142341)
via cfe-commits
cfe-commits at lists.llvm.org
Sat Jun 7 00:55:43 PDT 2025
Author: Shamshura Egor
Date: 2025-06-07T09:55:40+02:00
New Revision: eec9431d37e22a627c78e2f345d41a9a40e0c1c0
URL: https://github.com/llvm/llvm-project/commit/eec9431d37e22a627c78e2f345d41a9a40e0c1c0
DIFF: https://github.com/llvm/llvm-project/commit/eec9431d37e22a627c78e2f345d41a9a40e0c1c0.diff
LOG: [Clang] Added explanation why a is trivial copyable evaluated to false. (#142341)
Added:
Modified:
clang/include/clang/Basic/DiagnosticSemaKinds.td
clang/lib/Sema/SemaTypeTraits.cpp
clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp
clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp
Removed:
################################################################################
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 8ba3bb099d741..e963612f387ef 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1764,7 +1764,8 @@ def err_user_defined_msg_constexpr : Error<
// Type traits explanations
def note_unsatisfied_trait : Note<"%0 is not %enum_select<TraitName>{"
- "%TriviallyRelocatable{trivially relocatable}"
+ "%TriviallyRelocatable{trivially relocatable}|"
+ "%TriviallyCopyable{trivially copyable}"
"}1">;
def note_unsatisfied_trait_reason
@@ -1774,8 +1775,10 @@ def note_unsatisfied_trait_reason
"%HasArcLifetime{has an ARC lifetime qualifier}|"
"%VLA{is a variably-modified type}|"
"%VBase{has a virtual base %1}|"
- "%NRBase{has a non-trivially-relocatable base %1}|"
- "%NRField{has a non-trivially-relocatable member %1 of type %2}|"
+ "%NTRBase{has a non-trivially-relocatable base %1}|"
+ "%NTRField{has a non-trivially-relocatable member %1 of type %2}|"
+ "%NTCBase{has a non-trivially-copyable base %1}|"
+ "%NTCField{has a non-trivially-copyable member %1 of type %2}|"
"%DeletedDtr{has a %select{deleted|user-provided}1 destructor}|"
"%UserProvidedCtr{has a user provided %select{copy|move}1 "
"constructor}|"
diff --git a/clang/lib/Sema/SemaTypeTraits.cpp b/clang/lib/Sema/SemaTypeTraits.cpp
index b849bbe94af62..330f2aa750a09 100644
--- a/clang/lib/Sema/SemaTypeTraits.cpp
+++ b/clang/lib/Sema/SemaTypeTraits.cpp
@@ -11,8 +11,10 @@
//===----------------------------------------------------------------------===//
#include "clang/AST/DeclCXX.h"
+#include "clang/AST/Type.h"
#include "clang/Basic/DiagnosticParse.h"
#include "clang/Basic/DiagnosticSema.h"
+#include "clang/Basic/TypeTraits.h"
#include "clang/Sema/EnterExpressionEvaluationContext.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
@@ -1938,6 +1940,7 @@ static std::optional<TypeTrait> StdNameToTypeTrait(StringRef Name) {
return llvm::StringSwitch<std::optional<TypeTrait>>(Name)
.Case("is_trivially_relocatable",
TypeTrait::UTT_IsCppTriviallyRelocatable)
+ .Case("is_trivially_copyable", TypeTrait::UTT_IsTriviallyCopyable)
.Default(std::nullopt);
}
@@ -2013,15 +2016,15 @@ static void DiagnoseNonTriviallyRelocatableReason(Sema &SemaRef,
<< B.getSourceRange();
if (!SemaRef.IsCXXTriviallyRelocatableType(B.getType()))
SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
- << diag::TraitNotSatisfiedReason::NRBase << B.getType()
+ << diag::TraitNotSatisfiedReason::NTRBase << B.getType()
<< B.getSourceRange();
}
for (const FieldDecl *Field : D->fields()) {
if (!Field->getType()->isReferenceType() &&
!SemaRef.IsCXXTriviallyRelocatableType(Field->getType()))
SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
- << diag::TraitNotSatisfiedReason::NRField << Field << Field->getType()
- << Field->getSourceRange();
+ << diag::TraitNotSatisfiedReason::NTRField << Field
+ << Field->getType() << Field->getSourceRange();
}
if (D->hasDeletedDestructor())
SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
@@ -2099,6 +2102,82 @@ static void DiagnoseNonTriviallyRelocatableReason(Sema &SemaRef,
SemaRef.Diag(D->getLocation(), diag::note_defined_here) << D;
}
+static void DiagnoseNonTriviallyCopyableReason(Sema &SemaRef,
+ SourceLocation Loc,
+ const CXXRecordDecl *D) {
+ for (const CXXBaseSpecifier &B : D->bases()) {
+ assert(B.getType()->getAsCXXRecordDecl() && "invalid base?");
+ if (B.isVirtual())
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::VBase << B.getType()
+ << B.getSourceRange();
+ if (!B.getType().isTriviallyCopyableType(D->getASTContext())) {
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::NTCBase << B.getType()
+ << B.getSourceRange();
+ }
+ }
+ for (const FieldDecl *Field : D->fields()) {
+ if (!Field->getType().isTriviallyCopyableType(Field->getASTContext()))
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::NTCField << Field
+ << Field->getType() << Field->getSourceRange();
+ }
+ CXXDestructorDecl *Dtr = D->getDestructor();
+ if (D->hasDeletedDestructor() || (Dtr && !Dtr->isTrivial()))
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::DeletedDtr
+ << !D->hasDeletedDestructor() << D->getDestructor()->getSourceRange();
+
+ for (const CXXMethodDecl *Method : D->methods()) {
+ if (Method->isTrivial() || !Method->isUserProvided()) {
+ continue;
+ }
+ auto SpecialMemberKind =
+ SemaRef.getDefaultedFunctionKind(Method).asSpecialMember();
+ switch (SpecialMemberKind) {
+ case CXXSpecialMemberKind::CopyConstructor:
+ case CXXSpecialMemberKind::MoveConstructor:
+ case CXXSpecialMemberKind::CopyAssignment:
+ case CXXSpecialMemberKind::MoveAssignment: {
+ bool IsAssignment =
+ SpecialMemberKind == CXXSpecialMemberKind::CopyAssignment ||
+ SpecialMemberKind == CXXSpecialMemberKind::MoveAssignment;
+ bool IsMove =
+ SpecialMemberKind == CXXSpecialMemberKind::MoveConstructor ||
+ SpecialMemberKind == CXXSpecialMemberKind::MoveAssignment;
+
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << (IsAssignment ? diag::TraitNotSatisfiedReason::UserProvidedAssign
+ : diag::TraitNotSatisfiedReason::UserProvidedCtr)
+ << IsMove << Method->getSourceRange();
+ break;
+ }
+ default:
+ break;
+ }
+ }
+}
+
+static void DiagnoseNonTriviallyCopyableReason(Sema &SemaRef,
+ SourceLocation Loc, QualType T) {
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait)
+ << T << diag::TraitName::TriviallyCopyable;
+
+ if (T->isReferenceType())
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::Ref;
+
+ const CXXRecordDecl *D = T->getAsCXXRecordDecl();
+ if (!D || D->isInvalidDecl())
+ return;
+
+ if (D->hasDefinition())
+ DiagnoseNonTriviallyCopyableReason(SemaRef, Loc, D);
+
+ SemaRef.Diag(D->getLocation(), diag::note_defined_here) << D;
+}
+
void Sema::DiagnoseTypeTraitDetails(const Expr *E) {
E = E->IgnoreParenImpCasts();
if (E->containsErrors())
@@ -2113,6 +2192,9 @@ void Sema::DiagnoseTypeTraitDetails(const Expr *E) {
case UTT_IsCppTriviallyRelocatable:
DiagnoseNonTriviallyRelocatableReason(*this, E->getBeginLoc(), Args[0]);
break;
+ case UTT_IsTriviallyCopyable:
+ DiagnoseNonTriviallyCopyableReason(*this, E->getBeginLoc(), Args[0]);
+ break;
default:
break;
}
diff --git a/clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp b/clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp
index 90cff1e66000c..498e202e26265 100644
--- a/clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp
+++ b/clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp
@@ -12,6 +12,14 @@ struct is_trivially_relocatable {
template <typename T>
constexpr bool is_trivially_relocatable_v = __builtin_is_cpp_trivially_relocatable(T);
+
+template <typename T>
+struct is_trivially_copyable {
+ static constexpr bool value = __is_trivially_copyable(T);
+};
+
+template <typename T>
+constexpr bool is_trivially_copyable_v = __is_trivially_copyable(T);
#endif
#ifdef STD2
@@ -25,6 +33,17 @@ using is_trivially_relocatable = __details_is_trivially_relocatable<T>;
template <typename T>
constexpr bool is_trivially_relocatable_v = __builtin_is_cpp_trivially_relocatable(T);
+
+template <typename T>
+struct __details_is_trivially_copyable {
+ static constexpr bool value = __is_trivially_copyable(T);
+};
+
+template <typename T>
+using is_trivially_copyable = __details_is_trivially_copyable<T>;
+
+template <typename T>
+constexpr bool is_trivially_copyable_v = __is_trivially_copyable(T);
#endif
@@ -45,6 +64,15 @@ using is_trivially_relocatable = __details_is_trivially_relocatable<T>;
template <typename T>
constexpr bool is_trivially_relocatable_v = is_trivially_relocatable<T>::value;
+
+template <typename T>
+struct __details_is_trivially_copyable : bool_constant<__is_trivially_copyable(T)> {};
+
+template <typename T>
+using is_trivially_copyable = __details_is_trivially_copyable<T>;
+
+template <typename T>
+constexpr bool is_trivially_copyable_v = is_trivially_copyable<T>::value;
#endif
}
@@ -60,6 +88,18 @@ static_assert(std::is_trivially_relocatable_v<int&>);
// expected-note at -1 {{'int &' is not trivially relocatable}} \
// expected-note at -1 {{because it is a reference type}}
+static_assert(std::is_trivially_copyable<int>::value);
+
+static_assert(std::is_trivially_copyable<int&>::value);
+// expected-error-re at -1 {{static assertion failed due to requirement 'std::{{.*}}is_trivially_copyable<int &>::value'}} \
+// expected-note at -1 {{'int &' is not trivially copyable}} \
+// expected-note at -1 {{because it is a reference type}}
+static_assert(std::is_trivially_copyable_v<int&>);
+// expected-error at -1 {{static assertion failed due to requirement 'std::is_trivially_copyable_v<int &>'}} \
+// expected-note at -1 {{'int &' is not trivially copyable}} \
+// expected-note at -1 {{because it is a reference type}}
+
+
namespace test_namespace {
using namespace std;
static_assert(is_trivially_relocatable<int&>::value);
@@ -70,6 +110,15 @@ namespace test_namespace {
// expected-error at -1 {{static assertion failed due to requirement 'is_trivially_relocatable_v<int &>'}} \
// expected-note at -1 {{'int &' is not trivially relocatable}} \
// expected-note at -1 {{because it is a reference type}}
+
+ static_assert(is_trivially_copyable<int&>::value);
+ // expected-error-re at -1 {{static assertion failed due to requirement '{{.*}}is_trivially_copyable<int &>::value'}} \
+ // expected-note at -1 {{'int &' is not trivially copyable}} \
+ // expected-note at -1 {{because it is a reference type}}
+ static_assert(is_trivially_copyable_v<int&>);
+ // expected-error at -1 {{static assertion failed due to requirement 'is_trivially_copyable_v<int &>'}} \
+ // expected-note at -1 {{'int &' is not trivially copyable}} \
+ // expected-note at -1 {{because it is a reference type}}
}
@@ -82,6 +131,14 @@ concept C = std::is_trivially_relocatable_v<T>; // #concept2
template <C T> void g(); // #cand2
+template <typename T>
+requires std::is_trivially_copyable<T>::value void f2(); // #cand3
+
+template <typename T>
+concept C2 = std::is_trivially_copyable_v<T>; // #concept4
+
+template <C2 T> void g2(); // #cand4
+
void test() {
f<int&>();
// expected-error at -1 {{no matching function for call to 'f'}} \
@@ -97,5 +154,20 @@ void test() {
// expected-note@#concept2 {{because 'std::is_trivially_relocatable_v<int &>' evaluated to false}} \
// expected-note@#concept2 {{'int &' is not trivially relocatable}} \
// expected-note@#concept2 {{because it is a reference type}}
+
+ f2<int&>();
+ // expected-error at -1 {{no matching function for call to 'f2'}} \
+ // expected-note@#cand3 {{candidate template ignored: constraints not satisfied [with T = int &]}} \
+ // expected-note-re@#cand3 {{because '{{.*}}is_trivially_copyable<int &>::value' evaluated to false}} \
+ // expected-note@#cand3 {{'int &' is not trivially copyable}} \
+ // expected-note@#cand3 {{because it is a reference type}}
+
+ g2<int&>();
+ // expected-error at -1 {{no matching function for call to 'g2'}} \
+ // expected-note@#cand4 {{candidate template ignored: constraints not satisfied [with T = int &]}} \
+ // expected-note@#cand4 {{because 'int &' does not satisfy 'C2'}} \
+ // expected-note@#concept4 {{because 'std::is_trivially_copyable_v<int &>' evaluated to false}} \
+ // expected-note@#concept4 {{'int &' is not trivially copyable}} \
+ // expected-note@#concept4 {{because it is a reference type}}
}
}
diff --git a/clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp b/clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp
index d9cab20f4febd..0256569fcca5f 100644
--- a/clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp
+++ b/clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp
@@ -144,3 +144,149 @@ static_assert(__builtin_is_cpp_trivially_relocatable(U2));
// expected-note@#tr-U2 {{'U2' defined here}}
}
+
+namespace trivially_copyable {
+struct B {
+ virtual ~B();
+};
+struct S : virtual B { // #tc-S
+ S();
+ int & a;
+ const int ci;
+ B & b;
+ B c;
+ ~S();
+};
+static_assert(__is_trivially_copyable(S));
+// expected-error at -1 {{static assertion failed due to requirement '__is_trivially_copyable(trivially_copyable::S)'}} \
+// expected-note at -1 {{'S' is not trivially copyable}} \
+// expected-note at -1 {{because it has a virtual base 'B'}} \
+// expected-note at -1 {{because it has a non-trivially-copyable base 'B'}} \
+// expected-note at -1 {{because it has a non-trivially-copyable member 'c' of type 'B'}} \
+// expected-note at -1 {{because it has a non-trivially-copyable member 'b' of type 'B &'}} \
+// expected-note at -1 {{because it has a non-trivially-copyable member 'a' of type 'int &'}} \
+// expected-note at -1 {{because it has a user-provided destructor}}
+// expected-note@#tc-S {{'S' defined here}}
+
+struct S2 { // #tc-S2
+ S2(S2&&);
+ S2& operator=(const S2&);
+};
+static_assert(__is_trivially_copyable(S2));
+// expected-error at -1 {{static assertion failed due to requirement '__is_trivially_copyable(trivially_copyable::S2)'}} \
+// expected-note at -1 {{'S2' is not trivially copyable}} \
+// expected-note at -1 {{because it has a user provided move constructor}} \
+// expected-note at -1 {{because it has a user provided copy assignment operator}} \
+// expected-note@#tc-S2 {{'S2' defined here}}
+
+struct S3 {
+ ~S3() = delete;
+};
+static_assert(__is_trivially_copyable(S3));
+
+struct S4 { // #tc-S4
+ ~S4();
+ B b;
+};
+static_assert(__is_trivially_copyable(S4));
+// expected-error at -1 {{static assertion failed due to requirement '__is_trivially_copyable(trivially_copyable::S4)'}} \
+// expected-note at -1 {{'S4' is not trivially copyable}} \
+// expected-note at -1 {{because it has a non-trivially-copyable member 'b' of type 'B'}} \
+// expected-note at -1 {{because it has a user-provided destructor}} \
+// expected-note@#tc-S4 {{'S4' defined here}}
+
+struct B1 {
+ int & a;
+};
+
+struct B2 {
+ int & a;
+};
+
+struct S5 : virtual B1, virtual B2 { // #tc-S5
+};
+static_assert(__is_trivially_copyable(S5));
+// expected-error at -1 {{static assertion failed due to requirement '__is_trivially_copyable(trivially_copyable::S5)'}} \
+// expected-note at -1 {{'S5' is not trivially copyable}} \
+// expected-note at -1 {{because it has a virtual base 'B1'}} \
+// expected-note at -1 {{because it has a virtual base 'B2'}} \
+// expected-note@#tc-S5 {{'S5' defined here}}
+
+struct B3 {
+ ~B3();
+};
+
+struct B4 {
+ ~B4();
+};
+
+struct S6 : B3, B4 { // #tc-S6
+};
+static_assert(__is_trivially_copyable(S6));
+// expected-error at -1 {{static assertion failed due to requirement '__is_trivially_copyable(trivially_copyable::S6)'}} \
+// expected-note at -1 {{because it has a non-trivially-copyable base 'B3'}} \
+// expected-note at -1 {{because it has a non-trivially-copyable base 'B4'}} \
+// expected-note at -1 {{because it has a user-provided destructor}} \
+// expected-note at -1 {{'S6' is not trivially copyable}} \
+// expected-note@#tc-S6 {{'S6' defined here}}
+
+struct S7 { // #tc-S7
+ S7(const S7&);
+};
+static_assert(__is_trivially_copyable(S7));
+// expected-error at -1 {{static assertion failed due to requirement '__is_trivially_copyable(trivially_copyable::S7)'}} \
+// expected-note at -1 {{because it has a user provided copy constructor}} \
+// expected-note at -1 {{'S7' is not trivially copyable}} \
+// expected-note@#tc-S7 {{'S7' defined here}}
+
+struct S8 { // #tc-S8
+ S8(S8&&);
+};
+static_assert(__is_trivially_copyable(S8));
+// expected-error at -1 {{static assertion failed due to requirement '__is_trivially_copyable(trivially_copyable::S8)'}} \
+// expected-note at -1 {{because it has a user provided move constructor}} \
+// expected-note at -1 {{'S8' is not trivially copyable}} \
+// expected-note@#tc-S8 {{'S8' defined here}}
+
+struct S9 { // #tc-S9
+ S9& operator=(const S9&);
+};
+static_assert(__is_trivially_copyable(S9));
+// expected-error at -1 {{static assertion failed due to requirement '__is_trivially_copyable(trivially_copyable::S9)'}} \
+// expected-note at -1 {{because it has a user provided copy assignment operator}} \
+// expected-note at -1 {{'S9' is not trivially copyable}} \
+// expected-note@#tc-S9 {{'S9' defined here}}
+
+struct S10 { // #tc-S10
+ S10& operator=(S10&&);
+};
+static_assert(__is_trivially_copyable(S10));
+// expected-error at -1 {{static assertion failed due to requirement '__is_trivially_copyable(trivially_copyable::S10)'}} \
+// expected-note at -1 {{because it has a user provided move assignment operator}} \
+// expected-note at -1 {{'S10' is not trivially copyable}} \
+// expected-note@#tc-S10 {{'S10' defined here}}
+
+struct B5 : B4 {
+};
+
+struct B6 : B5 {
+};
+
+struct S11 : B6 { // #tc-S11
+};
+static_assert(__is_trivially_copyable(S11));
+// expected-error at -1 {{static assertion failed due to requirement '__is_trivially_copyable(trivially_copyable::S11)'}} \
+// expected-note at -1 {{because it has a non-trivially-copyable base 'B6'}} \
+// expected-note at -1 {{'S11' is not trivially copyable}} \
+// expected-note@#tc-S11 {{'S11' defined here}}
+
+struct S12 : B6 { // #tc-S12
+ ~S12() = delete;
+};
+static_assert(__is_trivially_copyable(S12));
+// expected-error at -1 {{static assertion failed due to requirement '__is_trivially_copyable(trivially_copyable::S12)'}} \
+// expected-note at -1 {{because it has a non-trivially-copyable base 'B6'}} \
+// expected-note at -1 {{because it has a deleted destructor}} \
+// expected-note at -1 {{'S12' is not trivially copyable}} \
+// expected-note@#tc-S12 {{'S12' defined here}}
+}
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