ahatanak created this revision.
ahatanak added a reviewer: rjmccall.
Issue a warning when non-trivial C structs (structs with '__weak' or '__strong'
fields) are copied or initialized by calls to memset, bzero, memcpy, and
memmove. This is similar to gcc's -Wclass-memaccess warning. It might be better
to add support for -Wclass-memaccess and make it cover both C and C++ structs
that are non-trivial.
rdar://problem/36124208
Repository:
rC Clang
https://reviews.llvm.org/D45310
Files:
include/clang/AST/NonTrivialCStructTypeVisitor.h
include/clang/Basic/DiagnosticSemaKinds.td
lib/CodeGen/CGNonTrivialStruct.cpp
lib/Sema/SemaChecking.cpp
test/SemaObjC/warn-nontrivial-struct-memaccess.m
Index: test/SemaObjC/warn-nontrivial-struct-memaccess.m
===================================================================
--- /dev/null
+++ test/SemaObjC/warn-nontrivial-struct-memaccess.m
@@ -0,0 +1,39 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fobjc-runtime-has-weak -x objective-c -fobjc-arc -verify %s
+
+void *memset(void *, int, __SIZE_TYPE__);
+void bzero(void *, __SIZE_TYPE__);
+void *memcpy(void *, const void *, __SIZE_TYPE__);
+void *memmove(void *, const void *, __SIZE_TYPE__);
+
+struct Trivial {
+ int f0;
+ volatile int f1;
+};
+
+struct NonTrivial0 {
+ int f0;
+ __weak id f1; // expected-note 2 {{non-trivial to default-initialize}} expected-note 2 {{non-trivial to copy}}
+ volatile int f2;
+ id f3[10]; // expected-note 2 {{non-trivial to default-initialize}} expected-note 2 {{non-trivial to copy}}
+};
+
+struct NonTrivial1 {
+ id f0; // expected-note 2 {{non-trivial to default-initialize}} expected-note 2 {{non-trivial to copy}}
+ int f1;
+ struct NonTrivial0 f2;
+};
+
+void testTrivial(struct Trivial *d, struct Trivial *s) {
+ memset(d, 0, sizeof(struct Trivial));
+ bzero(d, sizeof(struct Trivial));
+ memcpy(d, s, sizeof(struct Trivial));
+ memmove(d, s, sizeof(struct Trivial));
+}
+
+void testNonTrivial1(struct NonTrivial1 *d, struct NonTrivial1 *s) {
+ memset(d, 0, sizeof(struct NonTrivial1)); // expected-warning {{that is not trivial to primitive-default-initialize}} expected-note {{explicitly cast the pointer to silence}}
+ memset((void *)d, 0, sizeof(struct NonTrivial1));
+ bzero(d, sizeof(struct NonTrivial1)); // expected-warning {{that is not trivial to primitive-default-initialize}} expected-note {{explicitly cast the pointer to silence}}
+ memcpy(d, s, sizeof(struct NonTrivial1)); // expected-warning {{that is not trivial to primitive-copy}} expected-note {{explicitly cast the pointer to silence}}
+ memmove(d, s, sizeof(struct NonTrivial1)); // expected-warning {{that is not trivial to primitive-copy}} expected-note {{explicitly cast the pointer to silence}}
+}
Index: lib/Sema/SemaChecking.cpp
===================================================================
--- lib/Sema/SemaChecking.cpp
+++ lib/Sema/SemaChecking.cpp
@@ -28,6 +28,7 @@
#include "clang/AST/ExprObjC.h"
#include "clang/AST/ExprOpenMP.h"
#include "clang/AST/NSAPI.h"
+#include "clang/AST/NonTrivialCStructTypeVisitor.h"
#include "clang/AST/OperationKinds.h"
#include "clang/AST/Stmt.h"
#include "clang/AST/TemplateBase.h"
@@ -7321,6 +7322,78 @@
return QualType();
}
+namespace {
+
+struct SearchNonTrivialToInitializeField : DefaultInitializedTypeVisitor<SearchNonTrivialToInitializeField> {
+ SearchNonTrivialToInitializeField(const Expr *E, Sema &S) : E(E), S(S) {}
+ void visitARCStrong(QualType FT, SourceLocation SL) {
+ S.DiagRuntimeBehavior(SL, E,
+ S.PDiag(diag::note_nontrivial_field) << 1);
+ }
+ void visitARCWeak(QualType FT, SourceLocation SL) {
+ S.DiagRuntimeBehavior(SL, E,
+ S.PDiag(diag::note_nontrivial_field) << 1);
+ }
+ void visitStruct(QualType FT, SourceLocation SL) {
+ for (const FieldDecl *FD : FT->castAs<RecordType>()->getDecl()->fields())
+ visit(FD->getType(), FD->getLocation());
+ }
+ void visitArray(QualType::PrimitiveDefaultInitializeKind PDIK, QualType FT,
+ SourceLocation SL) {
+ const auto *AT = getContext().getAsConstantArrayType(FT);
+ visit(PDIK, getContext().getBaseElementType(AT), SL);
+ }
+ void visitTrivial(QualType FT, SourceLocation SL) {}
+
+ static void diag(QualType RT, const Expr *E, Sema &S) {
+ SearchNonTrivialToInitializeField(E, S).visitStruct(RT, SourceLocation());
+ }
+
+ ASTContext &getContext() {
+ return S.getASTContext();
+ }
+
+ const Expr *E;
+ Sema &S;
+};
+
+struct SearchNonTrivialToCopyField : CopiedTypeVisitor<SearchNonTrivialToCopyField, false> {
+ SearchNonTrivialToCopyField(const Expr *E, Sema &S) : E(E), S(S) {}
+ void visitARCStrong(QualType FT, SourceLocation SL) {
+ S.DiagRuntimeBehavior(SL, E,
+ S.PDiag(diag::note_nontrivial_field) << 0);
+ }
+ void visitARCWeak(QualType FT, SourceLocation SL) {
+ S.DiagRuntimeBehavior(SL, E,
+ S.PDiag(diag::note_nontrivial_field) << 0);
+ }
+ void visitStruct(QualType FT, SourceLocation SL) {
+ for (const FieldDecl *FD : FT->castAs<RecordType>()->getDecl()->fields())
+ visit(FD->getType(), FD->getLocation());
+ }
+ void visitArray(QualType::PrimitiveCopyKind PCK, QualType FT,
+ SourceLocation SL) {
+ const auto *AT = getContext().getAsConstantArrayType(FT);
+ visit(PCK, getContext().getBaseElementType(AT), SL);
+ }
+ void preVisit(QualType::PrimitiveCopyKind PCK, QualType FT, SourceLocation SL) {}
+ void visitTrivial(QualType FT, SourceLocation SL) {}
+ void visitVolatileTrivial(QualType FT, SourceLocation SL) {}
+
+ static void diag(QualType RT, const Expr *E, Sema &S) {
+ SearchNonTrivialToCopyField(E, S).visitStruct(RT, SourceLocation());
+ }
+
+ ASTContext &getContext() {
+ return S.getASTContext();
+ }
+
+ const Expr *E;
+ Sema &S;
+};
+
+}
+
/// \brief Check for dangerous or invalid arguments to memset().
///
/// This issues warnings on known problematic, dangerous or unspecified
@@ -7486,7 +7559,23 @@
PDiag(diag::warn_arc_object_memaccess)
<< ArgIdx << FnName << PointeeTy
<< Call->getCallee()->getSourceRange());
- else
+ else if (const auto *RT = PointeeTy->getAs<RecordType>()) {
+ if ((BId == Builtin::BImemset || BId == Builtin::BIbzero) &&
+ RT->getDecl()->isNonTrivialToPrimitiveDefaultInitialize()) {
+ DiagRuntimeBehavior(Dest->getExprLoc(), Dest,
+ PDiag(diag::warn_cstruct_memaccess) << ArgIdx << FnName
+ << PointeeTy << 0);
+ SearchNonTrivialToInitializeField::diag(PointeeTy, Dest, *this);
+ } else if ((BId == Builtin::BImemcpy || BId == Builtin::BImemmove) &&
+ RT->getDecl()->isNonTrivialToPrimitiveCopy()) {
+ DiagRuntimeBehavior(Dest->getExprLoc(), Dest,
+ PDiag(diag::warn_cstruct_memaccess) << ArgIdx << FnName
+ << PointeeTy << 1);
+ SearchNonTrivialToCopyField::diag(PointeeTy, Dest, *this);
+ } else {
+ continue;
+ }
+ } else
continue;
DiagRuntimeBehavior(
Index: lib/CodeGen/CGNonTrivialStruct.cpp
===================================================================
--- lib/CodeGen/CGNonTrivialStruct.cpp
+++ lib/CodeGen/CGNonTrivialStruct.cpp
@@ -14,6 +14,7 @@
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
+#include "clang/AST/NonTrivialCStructTypeVisitor.h"
#include "llvm/Support/ScopedPrinter.h"
#include <array>
@@ -31,101 +32,6 @@
enum { DstIdx = 0, SrcIdx = 1 };
const char *ValNameStr[2] = {"dst", "src"};
-template <class Derived, class RetTy = void> struct DestructedTypeVisitor {
- template <class... Ts> RetTy visit(QualType FT, Ts &&... Args) {
- return asDerived().visit(FT.isDestructedType(), FT,
- std::forward<Ts>(Args)...);
- }
-
- template <class... Ts>
- RetTy visit(QualType::DestructionKind DK, QualType FT, Ts &&... Args) {
- if (asDerived().getContext().getAsArrayType(FT))
- return asDerived().visitArray(DK, FT, std::forward<Ts>(Args)...);
-
- switch (DK) {
- case QualType::DK_objc_strong_lifetime:
- return asDerived().visitARCStrong(FT, std::forward<Ts>(Args)...);
- case QualType::DK_nontrivial_c_struct:
- return asDerived().visitStruct(FT, std::forward<Ts>(Args)...);
- case QualType::DK_none:
- return asDerived().visitTrivial(FT, std::forward<Ts>(Args)...);
- case QualType::DK_cxx_destructor:
- return asDerived().visitCXXDestructor(FT, std::forward<Ts>(Args)...);
- case QualType::DK_objc_weak_lifetime:
- return asDerived().visitARCWeak(FT, std::forward<Ts>(Args)...);
- }
-
- llvm_unreachable("unknown destruction kind");
- }
-
- Derived &asDerived() { return static_cast<Derived &>(*this); }
-};
-
-template <class Derived, class RetTy = void>
-struct DefaultInitializedTypeVisitor {
- template <class... Ts> RetTy visit(QualType FT, Ts &&... Args) {
- return asDerived().visit(FT.isNonTrivialToPrimitiveDefaultInitialize(), FT,
- std::forward<Ts>(Args)...);
- }
-
- template <class... Ts>
- RetTy visit(QualType::PrimitiveDefaultInitializeKind PDIK, QualType FT,
- Ts &&... Args) {
- if (asDerived().getContext().getAsArrayType(FT))
- return asDerived().visitArray(PDIK, FT, std::forward<Ts>(Args)...);
-
- switch (PDIK) {
- case QualType::PDIK_ARCStrong:
- return asDerived().visitARCStrong(FT, std::forward<Ts>(Args)...);
- case QualType::PDIK_ARCWeak:
- return asDerived().visitARCWeak(FT, std::forward<Ts>(Args)...);
- case QualType::PDIK_Struct:
- return asDerived().visitStruct(FT, std::forward<Ts>(Args)...);
- case QualType::PDIK_Trivial:
- return asDerived().visitTrivial(FT, std::forward<Ts>(Args)...);
- }
-
- llvm_unreachable("unknown default-initialize kind");
- }
-
- Derived &asDerived() { return static_cast<Derived &>(*this); }
-};
-
-template <class Derived, bool IsMove, class RetTy = void>
-struct CopiedTypeVisitor {
- template <class... Ts> RetTy visit(QualType FT, Ts &&... Args) {
- QualType::PrimitiveCopyKind PCK =
- IsMove ? FT.isNonTrivialToPrimitiveDestructiveMove()
- : FT.isNonTrivialToPrimitiveCopy();
- return asDerived().visit(PCK, FT, std::forward<Ts>(Args)...);
- }
-
- template <class... Ts>
- RetTy visit(QualType::PrimitiveCopyKind PCK, QualType FT, Ts &&... Args) {
- asDerived().preVisit(PCK, FT, std::forward<Ts>(Args)...);
-
- if (asDerived().getContext().getAsArrayType(FT))
- return asDerived().visitArray(PCK, FT, std::forward<Ts>(Args)...);
-
- switch (PCK) {
- case QualType::PCK_ARCStrong:
- return asDerived().visitARCStrong(FT, std::forward<Ts>(Args)...);
- case QualType::PCK_ARCWeak:
- return asDerived().visitARCWeak(FT, std::forward<Ts>(Args)...);
- case QualType::PCK_Struct:
- return asDerived().visitStruct(FT, std::forward<Ts>(Args)...);
- case QualType::PCK_Trivial:
- return asDerived().visitTrivial(FT, std::forward<Ts>(Args)...);
- case QualType::PCK_VolatileTrivial:
- return asDerived().visitVolatileTrivial(FT, std::forward<Ts>(Args)...);
- }
-
- llvm_unreachable("unknown primitive copy kind");
- }
-
- Derived &asDerived() { return static_cast<Derived &>(*this); }
-};
-
template <class Derived> struct StructVisitor {
StructVisitor(ASTContext &Ctx) : Ctx(Ctx) {}
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -612,6 +612,13 @@
"'%2'">;
def warn_builtin_unknown : Warning<"use of unknown builtin %0">,
InGroup<ImplicitFunctionDeclare>, DefaultError;
+def warn_cstruct_memaccess : Warning<
+ "%select{destination for|source of|first operand of|second operand of}0 this "
+ "%1 call is a pointer to record %2 that is not trivial to "
+ "%select{primitive-default-initialize|primitive-copy}3">,
+ InGroup<DiagGroup<"cstruct-memaccess">>;
+def note_nontrivial_field : Note<
+ "field is non-trivial to %select{copy|default-initialize}0">;
def warn_dyn_class_memaccess : Warning<
"%select{destination for|source of|first operand of|second operand of}0 this "
"%1 call is a pointer to %select{|class containing a }2dynamic class %3; "
Index: include/clang/AST/NonTrivialCStructTypeVisitor.h
===================================================================
--- /dev/null
+++ include/clang/AST/NonTrivialCStructTypeVisitor.h
@@ -0,0 +1,118 @@
+//===--- TypeVisitor.h - Visitor for Type subclasses ------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the TypeVisitor interface.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_NON_TRIVIAL_CSTRUCT_TYPE_VISITOR_H
+#define LLVM_CLANG_NON_TRIVIAL_CSTRUCT_TYPE_VISITOR_H
+
+#include "clang/AST/Type.h"
+
+namespace clang {
+
+template <class Derived, class RetTy = void> struct DestructedTypeVisitor {
+ template <class... Ts> RetTy visit(QualType FT, Ts &&... Args) {
+ return asDerived().visit(FT.isDestructedType(), FT,
+ std::forward<Ts>(Args)...);
+ }
+
+ template <class... Ts>
+ RetTy visit(QualType::DestructionKind DK, QualType FT, Ts &&... Args) {
+ if (asDerived().getContext().getAsArrayType(FT))
+ return asDerived().visitArray(DK, FT, std::forward<Ts>(Args)...);
+
+ switch (DK) {
+ case QualType::DK_objc_strong_lifetime:
+ return asDerived().visitARCStrong(FT, std::forward<Ts>(Args)...);
+ case QualType::DK_nontrivial_c_struct:
+ return asDerived().visitStruct(FT, std::forward<Ts>(Args)...);
+ case QualType::DK_none:
+ return asDerived().visitTrivial(FT, std::forward<Ts>(Args)...);
+ case QualType::DK_cxx_destructor:
+ return asDerived().visitCXXDestructor(FT, std::forward<Ts>(Args)...);
+ case QualType::DK_objc_weak_lifetime:
+ return asDerived().visitARCWeak(FT, std::forward<Ts>(Args)...);
+ }
+
+ llvm_unreachable("unknown destruction kind");
+ }
+
+ Derived &asDerived() { return static_cast<Derived &>(*this); }
+};
+
+template <class Derived, class RetTy = void>
+struct DefaultInitializedTypeVisitor {
+ template <class... Ts> RetTy visit(QualType FT, Ts &&... Args) {
+ return asDerived().visit(FT.isNonTrivialToPrimitiveDefaultInitialize(), FT,
+ std::forward<Ts>(Args)...);
+ }
+
+ template <class... Ts>
+ RetTy visit(QualType::PrimitiveDefaultInitializeKind PDIK, QualType FT,
+ Ts &&... Args) {
+ if (asDerived().getContext().getAsArrayType(FT))
+ return asDerived().visitArray(PDIK, FT, std::forward<Ts>(Args)...);
+
+ switch (PDIK) {
+ case QualType::PDIK_ARCStrong:
+ return asDerived().visitARCStrong(FT, std::forward<Ts>(Args)...);
+ case QualType::PDIK_ARCWeak:
+ return asDerived().visitARCWeak(FT, std::forward<Ts>(Args)...);
+ case QualType::PDIK_Struct:
+ return asDerived().visitStruct(FT, std::forward<Ts>(Args)...);
+ case QualType::PDIK_Trivial:
+ return asDerived().visitTrivial(FT, std::forward<Ts>(Args)...);
+ }
+
+ llvm_unreachable("unknown default-initialize kind");
+ }
+
+ Derived &asDerived() { return static_cast<Derived &>(*this); }
+};
+
+template <class Derived, bool IsMove, class RetTy = void>
+struct CopiedTypeVisitor {
+ template <class... Ts> RetTy visit(QualType FT, Ts &&... Args) {
+ QualType::PrimitiveCopyKind PCK =
+ IsMove ? FT.isNonTrivialToPrimitiveDestructiveMove()
+ : FT.isNonTrivialToPrimitiveCopy();
+ return asDerived().visit(PCK, FT, std::forward<Ts>(Args)...);
+ }
+
+ template <class... Ts>
+ RetTy visit(QualType::PrimitiveCopyKind PCK, QualType FT, Ts &&... Args) {
+ asDerived().preVisit(PCK, FT, std::forward<Ts>(Args)...);
+
+ if (asDerived().getContext().getAsArrayType(FT))
+ return asDerived().visitArray(PCK, FT, std::forward<Ts>(Args)...);
+
+ switch (PCK) {
+ case QualType::PCK_ARCStrong:
+ return asDerived().visitARCStrong(FT, std::forward<Ts>(Args)...);
+ case QualType::PCK_ARCWeak:
+ return asDerived().visitARCWeak(FT, std::forward<Ts>(Args)...);
+ case QualType::PCK_Struct:
+ return asDerived().visitStruct(FT, std::forward<Ts>(Args)...);
+ case QualType::PCK_Trivial:
+ return asDerived().visitTrivial(FT, std::forward<Ts>(Args)...);
+ case QualType::PCK_VolatileTrivial:
+ return asDerived().visitVolatileTrivial(FT, std::forward<Ts>(Args)...);
+ }
+
+ llvm_unreachable("unknown primitive copy kind");
+ }
+
+ Derived &asDerived() { return static_cast<Derived &>(*this); }
+};
+
+} // end namespace clang
+
+#endif
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