[clang] Changed Checks from TriviallyCopyable to TriviallyCopyConstructible (PR #76680)
Bhuminjay Soni via cfe-commits
cfe-commits at lists.llvm.org
Mon Jan 1 08:16:47 PST 2024
https://github.com/11happy updated https://github.com/llvm/llvm-project/pull/76680
>From 3c8dfcf96e732f4546f8019c0111fd873b233162 Mon Sep 17 00:00:00 2001
From: 11happy <soni5happy at gmail.com>
Date: Mon, 1 Jan 2024 19:53:45 +0530
Subject: [PATCH 1/2] Changed Checks from TriviallyCopyable to
TriviallyCopyConstructible
Signed-off-by: 11happy <soni5happy at gmail.com>
---
clang/include/clang/AST/DeclCXX.h | 3 +++
clang/include/clang/AST/Type.h | 3 +++
clang/lib/AST/DeclCXX.cpp | 13 ++++++++++
clang/lib/AST/Type.cpp | 43 +++++++++++++++++++++++++++++++
clang/lib/Sema/SemaStmt.cpp | 2 +-
5 files changed, 63 insertions(+), 1 deletion(-)
diff --git a/clang/include/clang/AST/DeclCXX.h b/clang/include/clang/AST/DeclCXX.h
index 432293583576b5..3ac0d6a9e083cd 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -1425,6 +1425,9 @@ class CXXRecordDecl : public RecordDecl {
/// (C++11 [class]p6).
bool isTriviallyCopyable() const;
+ /// Determine whether this class is considered trivially copyable per
+ bool isTriviallyCopyConstructible() const;
+
/// Determine whether this class is considered trivial.
///
/// C++11 [class]p6:
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 1afa693672860f..bce2256f96a828 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -917,6 +917,9 @@ class QualType {
/// Return true if this is a trivially copyable type (C++0x [basic.types]p9)
bool isTriviallyCopyableType(const ASTContext &Context) const;
+ /// Return true if this is a trivially copyable type
+ bool isTriviallyCopyConstructibleType(const ASTContext &Context) const;
+
/// Return true if this is a trivially relocatable type.
bool isTriviallyRelocatableType(const ASTContext &Context) const;
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index c944862fcefeee..98b0a6dc28ea2f 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -587,6 +587,19 @@ bool CXXRecordDecl::isTriviallyCopyable() const {
return true;
}
+bool CXXRecordDecl::isTriviallyCopyConstructible() const {
+
+ // A trivially copy constructible class is a class that:
+ // -- has no non-trivial copy constructors,
+ if (hasNonTrivialCopyConstructor())
+ return false;
+ // -- has a trivial destructor.
+ if (!hasTrivialDestructor())
+ return false;
+
+ return true;
+}
+
void CXXRecordDecl::markedVirtualFunctionPure() {
// C++ [class.abstract]p2:
// A class is abstract if it has at least one pure virtual function.
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 160a725939ccd4..9c8b25798a0a95 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -2644,6 +2644,49 @@ bool QualType::isTriviallyCopyableType(const ASTContext &Context) const {
return false;
}
+bool QualType::isTriviallyCopyConstructibleType(
+ const ASTContext &Context) const {
+ if ((*this)->isArrayType())
+ return Context.getBaseElementType(*this).isTriviallyCopyConstructibleType(
+ Context);
+
+ if (hasNonTrivialObjCLifetime())
+ return false;
+
+ // C++11 [basic.types]p9 - See Core 2094
+ // Scalar types, trivially copyable class types, arrays of such types, and
+ // cv-qualified versions of these types are collectively
+ // called trivially copy constructible types.
+
+ QualType CanonicalType = getCanonicalType();
+ if (CanonicalType->isDependentType())
+ return false;
+
+ if (CanonicalType->isSizelessBuiltinType())
+ return true;
+
+ // Return false for incomplete types after skipping any incomplete array types
+ // which are expressly allowed by the standard and thus our API.
+ if (CanonicalType->isIncompleteType())
+ return false;
+
+ // As an extension, Clang treats vector types as Scalar types.
+ if (CanonicalType->isScalarType() || CanonicalType->isVectorType())
+ return true;
+
+ if (const auto *RT = CanonicalType->getAs<RecordType>()) {
+ if (const auto *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
+ if (!ClassDecl->isTriviallyCopyConstructible())
+ return false;
+ }
+
+ return true;
+ }
+
+ // No other types can match.
+ return false;
+}
+
bool QualType::isTriviallyRelocatableType(const ASTContext &Context) const {
QualType BaseElementType = Context.getBaseElementType(*this);
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index f0b03db690843a..21efe25ed84a3d 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -3200,7 +3200,7 @@ static void DiagnoseForRangeConstVariableCopies(Sema &SemaRef,
// (The function `getTypeSize` returns the size in bits.)
ASTContext &Ctx = SemaRef.Context;
if (Ctx.getTypeSize(VariableType) <= 64 * 8 &&
- (VariableType.isTriviallyCopyableType(Ctx) ||
+ (VariableType.isTriviallyCopyConstructibleType(Ctx) ||
hasTrivialABIAttr(VariableType)))
return;
>From 57b50cb0fc242d994558ddcb8226c3a785763e87 Mon Sep 17 00:00:00 2001
From: 11happy <soni5happy at gmail.com>
Date: Mon, 1 Jan 2024 21:46:17 +0530
Subject: [PATCH 2/2] Added tests
Signed-off-by: 11happy <soni5happy at gmail.com>
---
...range-loop-analysis-trivially-copyable.cpp | 25 +++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/clang/test/SemaCXX/warn-range-loop-analysis-trivially-copyable.cpp b/clang/test/SemaCXX/warn-range-loop-analysis-trivially-copyable.cpp
index e345ef40aed9ca..8fa387908c3658 100644
--- a/clang/test/SemaCXX/warn-range-loop-analysis-trivially-copyable.cpp
+++ b/clang/test/SemaCXX/warn-range-loop-analysis-trivially-copyable.cpp
@@ -33,6 +33,17 @@ void test_TriviallyCopyable_64_bytes() {
for (const auto r : records)
(void)r;
}
+void test_TriviallyCopyConstructible_64_bytes() {
+ struct Record {
+ char a[64];
+ Record& operator=(Record const& other){return *this;};
+
+ };
+
+ Record records[8];
+ for (const auto r : records)
+ (void)r;
+}
void test_TriviallyCopyable_65_bytes() {
struct Record {
@@ -47,6 +58,19 @@ void test_TriviallyCopyable_65_bytes() {
(void)r;
}
+void test_TriviallyCopyConstructible_65_bytes() {
+ struct Record {
+ char a[65];
+ Record& operator=(Record const& other){return *this;};
+
+ };
+ // expected-warning at +3 {{loop variable 'r' creates a copy from type 'const Record'}}
+ // expected-note at +2 {{use reference type 'const Record &' to prevent copying}}
+ Record records[8];
+ for (const auto r : records)
+ (void)r;
+}
+
void test_NonTriviallyCopyable() {
struct Record {
Record() {}
@@ -87,3 +111,4 @@ void test_TrivialABI_65_bytes() {
for (const auto r : records)
(void)r;
}
+
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