https://github.com/higher-performance updated
https://github.com/llvm/llvm-project/pull/141133
>From f384cb655ca7412f80427fafb47a26c74917b9ff Mon Sep 17 00:00:00 2001
From: higher-performance <higher.performance.git...@gmail.com>
Date: Thu, 22 May 2025 16:30:29 -0400
Subject: [PATCH 1/2] Include [[clang::require_explicit_initialization]]
warnings in system headers
Fixes #141103
---
.../clang/Basic/DiagnosticSemaKinds.td | 3 ++-
clang/test/SemaCXX/uninitialized.cpp | 27 ++++++++++++++++---
2 files changed, 25 insertions(+), 5 deletions(-)
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td
b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 0b2553d82153c..934f4453f02b9 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2479,7 +2479,8 @@ def note_uninit_reference_member : Note<
"uninitialized reference member is here">;
def warn_field_requires_explicit_init : Warning<
"field %select{%1|in %1}0 requires explicit initialization but is not "
- "explicitly initialized">, InGroup<UninitializedExplicitInit>;
+ "explicitly initialized">, InGroup<UninitializedExplicitInit>,
+ ShowInSystemHeader;
def warn_field_is_uninit : Warning<"field %0 is uninitialized when used here">,
InGroup<Uninitialized>;
def warn_base_class_is_uninit : Warning<
diff --git a/clang/test/SemaCXX/uninitialized.cpp
b/clang/test/SemaCXX/uninitialized.cpp
index c7cef3e06fb2b..98e1e93ec53cc 100644
--- a/clang/test/SemaCXX/uninitialized.cpp
+++ b/clang/test/SemaCXX/uninitialized.cpp
@@ -2,6 +2,23 @@
// RUN: %clang_cc1 -fsyntax-only -Wall -Wc++20-compat -Wuninitialized
-Wno-unused-value -Wno-unused-lambda-capture -Wno-uninitialized-const-reference
-std=c++1z -verify %s -fexperimental-new-constant-interpreter
// RUN: %clang_cc1 -fsyntax-only -Wall -Wc++20-compat -Wuninitialized
-Wno-unused-value -Wno-unused-lambda-capture -Wno-uninitialized-const-reference
-std=c++20 -verify %s
+#if defined(BE_THE_HEADER)
+
+// Wuninitialized-explicit-init should warn in system headers
(std::construct_at...) too.
+
+#pragma clang system_header
+namespace std {
+template <class T, class... U>
+constexpr T* construct_at(T* ptr, U&&... args) {
+ return ::new (static_cast<void*>(ptr)) T(static_cast<U&&>(args)...); //
#FIELD_EMBED2_CONSTRUCT_AT
+}
+}
+
+#else
+
+#define BE_THE_HEADER
+#include __FILE__
+
void* operator new(__SIZE_TYPE__, void*);
// definitions for std::move
@@ -1564,11 +1581,11 @@ void aggregate() {
explicit F(const char(&)[1]) : f1() {
// expected-warning@+1 {{field in 'Embed' requires explicit
initialization but is not explicitly initialized}} expected-note@#FIELD_EMBED2
{{'embed2' declared here}}
::new(static_cast<void*>(&f1)) decltype(f1);
- // expected-warning@+1 {{field in 'Embed' requires explicit
initialization but is not explicitly initialized}} expected-note@#FIELD_EMBED2
{{'embed2' declared here}}
- ::new(static_cast<void*>(&f1)) decltype(f1)();
+ // expected-warning@#FIELD_EMBED2_CONSTRUCT_AT {{field in 'Embed'
requires explicit initialization but is not explicitly initialized}}
expected-note@+1 {{in instantiation of function template specialization
'std::construct_at<Embed>' requested here}} expected-note@#FIELD_EMBED2
{{'embed2' declared here}}
+ std::construct_at(&f1);
#if __cplusplus >= 202002L
- // expected-warning@+1 {{field 'embed2' requires explicit initialization
but is not explicitly initialized}} expected-note@#FIELD_EMBED2 {{'embed2'
declared here}}
- ::new(static_cast<void*>(&f1)) decltype(f1)(1);
+ // expected-warning@#FIELD_EMBED2_CONSTRUCT_AT {{field 'embed2' requires
explicit initialization but is not explicitly initialized}} expected-note@+1
{{in instantiation of function template specialization
'std::construct_at<Embed, int>' requested here}} expected-note@#FIELD_EMBED2
{{'embed2' declared here}}
+ std::construct_at(&f1, 1);
#endif
// expected-warning@+1 {{field 'embed2' requires explicit initialization
but is not explicitly initialized}} expected-note@#FIELD_EMBED2 {{'embed2'
declared here}}
::new(static_cast<void*>(&f1)) decltype(f1){1};
@@ -1726,3 +1743,5 @@ void aggregate() {
InheritWithExplicit<Special> specialized_implicit; // no-warning
(void)specialized_implicit;
}
+
+#endif
>From c5d3605436197426f08724369c6e0acf534b6cab Mon Sep 17 00:00:00 2001
From: higher-performance <higher.performance.git...@gmail.com>
Date: Tue, 27 May 2025 16:37:01 -0400
Subject: [PATCH 2/2] Suppress [[clang::require_explicit_initialization]] in
unevaluated operands
---
clang/include/clang/Basic/AttrDocs.td | 6 +++---
clang/lib/Sema/SemaInit.cpp | 14 +++++++++-----
clang/test/Sema/uninit-variables.c | 2 ++
clang/test/SemaCXX/uninitialized.cpp | 2 ++
4 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/clang/include/clang/Basic/AttrDocs.td
b/clang/include/clang/Basic/AttrDocs.td
index 43442f177ab7b..fefdaba7f8bf5 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -1750,9 +1750,9 @@ to guard against use of uninitialized memory.
Rather, it is intended for use in "parameter-objects", used to simulate,
for example, the passing of named parameters.
-The attribute generates a warning when explicit initializers for such
-variables are not provided (this occurs regardless of whether any in-class
field
-initializers exist):
+Except inside unevaluated contexts, the attribute generates a warning when
+explicit initializers for such variables are not provided (this occurs
+regardless of whether any in-class field initializers exist):
.. code-block:: c++
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 0844cb4d6c3cd..95746b35f71ef 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -790,7 +790,8 @@ void InitListChecker::FillInEmptyInitForField(unsigned
Init, FieldDecl *Field,
return;
}
- if (!VerifyOnly && Field->hasAttr<ExplicitInitAttr>()) {
+ if (!VerifyOnly && Field->hasAttr<ExplicitInitAttr>() &&
+ !SemaRef.isUnevaluatedContext()) {
SemaRef.Diag(ILE->getExprLoc(), diag::warn_field_requires_explicit_init)
<< /* Var-in-Record */ 0 << Field;
SemaRef.Diag(Field->getLocation(), diag::note_entity_declared_at)
@@ -4631,7 +4632,8 @@ static void TryConstructorInitialization(Sema &S,
Kind.getKind() == InitializationKind::IK_Direct) &&
!(CtorDecl->isCopyOrMoveConstructor() && CtorDecl->isImplicit()) &&
DestRecordDecl->isAggregate() &&
- DestRecordDecl->hasUninitializedExplicitInitFields()) {
+ DestRecordDecl->hasUninitializedExplicitInitFields() &&
+ !S.isUnevaluatedContext()) {
S.Diag(Kind.getLocation(), diag::warn_field_requires_explicit_init)
<< /* Var-in-Record */ 1 << DestRecordDecl;
emitUninitializedExplicitInitFields(S, DestRecordDecl);
@@ -5995,7 +5997,8 @@ static void TryOrBuildParenListInitialization(
} else {
// We've processed all of the args, but there are still members that
// have to be initialized.
- if (!VerifyOnly && FD->hasAttr<ExplicitInitAttr>()) {
+ if (!VerifyOnly && FD->hasAttr<ExplicitInitAttr>() &&
+ !S.isUnevaluatedContext()) {
S.Diag(Kind.getLocation(), diag::warn_field_requires_explicit_init)
<< /* Var-in-Record */ 0 << FD;
S.Diag(FD->getLocation(), diag::note_entity_declared_at) << FD;
@@ -6617,7 +6620,7 @@ void InitializationSequence::InitializeFrom(Sema &S,
if (RecordDecl *Rec = DestType->getAsRecordDecl()) {
VarDecl *Var = dyn_cast_or_null<VarDecl>(Entity.getDecl());
if (Rec->hasUninitializedExplicitInitFields()) {
- if (Var && !Initializer) {
+ if (Var && !Initializer && !S.isUnevaluatedContext()) {
S.Diag(Var->getLocation(), diag::warn_field_requires_explicit_init)
<< /* Var-in-Record */ 1 << Rec;
emitUninitializedExplicitInitFields(S, Rec);
@@ -7481,7 +7484,8 @@ PerformConstructorInitialization(Sema &S,
if (RD && RD->isAggregate() && RD->hasUninitializedExplicitInitFields())
{
unsigned I = 0;
for (const FieldDecl *FD : RD->fields()) {
- if (I >= ConstructorArgs.size() && FD->hasAttr<ExplicitInitAttr>()) {
+ if (I >= ConstructorArgs.size() && FD->hasAttr<ExplicitInitAttr>() &&
+ !S.isUnevaluatedContext()) {
S.Diag(Loc, diag::warn_field_requires_explicit_init)
<< /* Var-in-Record */ 0 << FD;
S.Diag(FD->getLocation(), diag::note_entity_declared_at) << FD;
diff --git a/clang/test/Sema/uninit-variables.c
b/clang/test/Sema/uninit-variables.c
index 6d79d419f72e7..17e83de5f489a 100644
--- a/clang/test/Sema/uninit-variables.c
+++ b/clang/test/Sema/uninit-variables.c
@@ -580,4 +580,6 @@ void aggregate() {
struct with_explicit_flex_array f = {2}; // expected-warning {{field
'flex_arr' requires explicit initialization but is not explicitly initialized}}
expected-note@#FIELD_FLEX_ARR {{'flex_arr' declared here}}
(void)f;
+
+ (void)sizeof({ struct with_explicit_field a; a; }); // no warning --
unevaluated operand
}
diff --git a/clang/test/SemaCXX/uninitialized.cpp
b/clang/test/SemaCXX/uninitialized.cpp
index 98e1e93ec53cc..251e888f73973 100644
--- a/clang/test/SemaCXX/uninitialized.cpp
+++ b/clang/test/SemaCXX/uninitialized.cpp
@@ -1642,6 +1642,8 @@ void aggregate() {
S::foo(S{.s1 = 100, .s4 = 100});
S::foo(S{.s1 = 100}); // expected-warning {{field 's4' requires explicit
initialization but is not explicitly initialized}} expected-note@#FIELD_S4
{{'s4' declared here}}
+ (void)sizeof(S{}); // no warning -- unevaluated operand
+
S s{.s1 = 100, .s4 = 100};
(void)s;
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
