leonardchan updated this revision to Diff 257153.
leonardchan marked an inline comment as done.
leonardchan added a comment.
Updated to address comments and added an RAII class for easier checking before
exiting functions.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D77836/new/
https://reviews.llvm.org/D77836
Files:
clang/include/clang/Sema/Initialization.h
clang/lib/Sema/SemaCast.cpp
clang/lib/Sema/SemaInit.cpp
clang/test/Frontend/noderef.c
clang/test/Frontend/noderef.cpp
Index: clang/test/Frontend/noderef.cpp
===================================================================
--- clang/test/Frontend/noderef.cpp
+++ clang/test/Frontend/noderef.cpp
@@ -80,12 +80,28 @@
int member;
int NODEREF *member2;
int NODEREF member3; // expected-warning{{'noderef' can only be used on an array or pointer type}}
+ int *member4;
+
+ int func() { return member; }
+ virtual int func_virt() { return member; }
+
+ A(NODEREF int *x) : member4(x) {} // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
};
+class Child : public A {};
+
void MemberPointer() {
int NODEREF A::*var = &A::member; // expected-warning{{'noderef' can only be used on an array or pointer type}}
}
+int MethodCall(NODEREF A *a) { // expected-note{{a declared here}}
+ return a->func(); // expected-warning{{dereferencing a; was declared with a 'noderef' type}}
+}
+
+int ChildCall(NODEREF Child *child) { // expected-note{{child declared here}}
+ return child->func(); // expected-warning{{dereferencing child; was declared with a 'noderef' type}}
+}
+
template <class Ty>
class B {
Ty NODEREF *member;
@@ -100,3 +116,37 @@
int NODEREF *glob_ptr; // expected-note{{glob_ptr declared here}}
int glob_int = *glob_ptr; // expected-warning{{dereferencing glob_ptr; was declared with a 'noderef' type}}
+
+void cast_from_void_ptr(NODEREF void *x) {
+ int *a = static_cast<int *>(x); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
+ int *b = reinterpret_cast<int *>(x); // Allow C-style casts through reinterpret_casts to be a hole
+ int *c = (int *)x; // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
+}
+
+int *static_cast_from_same_ptr_type(NODEREF int *x) {
+ return static_cast<int *>(x); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
+}
+
+A *dynamic_cast_up(NODEREF Child *child) {
+ return dynamic_cast<A *>(child); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
+}
+
+Child *dynamic_cast_down(NODEREF A *a) {
+ return dynamic_cast<Child *>(a); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
+}
+
+A *dynamic_cast_side(NODEREF A *a) {
+ return dynamic_cast<A *>(a); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
+}
+
+void *dynamic_cast_to_void_ptr(NODEREF A *a) {
+ return dynamic_cast<void *>(a); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
+}
+
+int *const_cast_check(NODEREF const int *x) {
+ return const_cast<int *>(x); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
+}
+
+const int *const_cast_check(NODEREF int *x) {
+ return const_cast<const int *>(x); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
+}
Index: clang/test/Frontend/noderef.c
===================================================================
--- clang/test/Frontend/noderef.c
+++ clang/test/Frontend/noderef.c
@@ -207,3 +207,7 @@
do {} while (*p); // expected-warning{{dereferencing p; was declared with a 'noderef' type}}
return *p; // expected-warning{{dereferencing p; was declared with a 'noderef' type}}
}
+
+int *explicit_cast(NODEREF int *x) {
+ return (int *)x; // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
+}
Index: clang/lib/Sema/SemaInit.cpp
===================================================================
--- clang/lib/Sema/SemaInit.cpp
+++ clang/lib/Sema/SemaInit.cpp
@@ -8179,9 +8179,13 @@
if (const auto *ToPtrType = Step->Type->getAs<PointerType>()) {
if (FromPtrType->getPointeeType()->hasAttr(attr::NoDeref) &&
!ToPtrType->getPointeeType()->hasAttr(attr::NoDeref)) {
- S.Diag(CurInit.get()->getExprLoc(),
- diag::warn_noderef_to_dereferenceable_pointer)
- << CurInit.get()->getSourceRange();
+ // Do not check static casts here because they are checked earlier
+ // in Sema::ActOnCXXNamedCast()
+ if (!Kind.isStaticCast()) {
+ S.Diag(CurInit.get()->getExprLoc(),
+ diag::warn_noderef_to_dereferenceable_pointer)
+ << CurInit.get()->getSourceRange();
+ }
}
}
}
Index: clang/lib/Sema/SemaCast.cpp
===================================================================
--- clang/lib/Sema/SemaCast.cpp
+++ clang/lib/Sema/SemaCast.cpp
@@ -159,6 +159,30 @@
PlaceholderKind = (BuiltinType::Kind) 0;
}
};
+
+ void CheckNoDeref(Sema &S, const QualType FromType, const QualType ToType,
+ SourceLocation OpLoc) {
+ if (const auto *PtrType = dyn_cast<PointerType>(FromType)) {
+ if (PtrType->getPointeeType()->hasAttr(attr::NoDeref)) {
+ if (const auto *DestType = dyn_cast<PointerType>(ToType)) {
+ if (!DestType->getPointeeType()->hasAttr(attr::NoDeref)) {
+ S.Diag(OpLoc, diag::warn_noderef_to_dereferenceable_pointer);
+ }
+ }
+ }
+ }
+ }
+
+ struct CheckNoDerefRAII {
+ CheckNoDerefRAII(CastOperation &Op) : Op(Op) {}
+ ~CheckNoDerefRAII() {
+ if (!Op.SrcExpr.isInvalid())
+ CheckNoDeref(Op.Self, Op.SrcExpr.get()->getType(), Op.ResultType,
+ Op.OpRange.getBegin());
+ }
+
+ CastOperation &Op;
+ };
}
static void DiagnoseCastQual(Sema &Self, const ExprResult &SrcExpr,
@@ -229,7 +253,6 @@
unsigned &msg,
CastKind &Kind);
-
/// ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast's.
ExprResult
Sema::ActOnCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
@@ -708,6 +731,8 @@
/// Refer to C++ 5.2.7 for details. Dynamic casts are used mostly for runtime-
/// checked downcasts in class hierarchies.
void CastOperation::CheckDynamicCast() {
+ CheckNoDerefRAII noderef_check(*this);
+
if (ValueKind == VK_RValue)
SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
else if (isPlaceholder())
@@ -861,6 +886,8 @@
/// const char *str = "literal";
/// legacy_function(const_cast\<char*\>(str));
void CastOperation::CheckConstCast() {
+ CheckNoDerefRAII noderef_check(*this);
+
if (ValueKind == VK_RValue)
SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
else if (isPlaceholder())
@@ -1018,6 +1045,8 @@
/// Refer to C++ 5.2.9 for details. Static casts are mostly used for making
/// implicit conversions explicit and getting rid of data loss warnings.
void CastOperation::CheckStaticCast() {
+ CheckNoDerefRAII noderef_check(*this);
+
if (isPlaceholder()) {
checkNonOverloadPlaceholders();
if (SrcExpr.isInvalid())
@@ -2525,6 +2554,8 @@
OpRange, msg, Kind);
if (SrcExpr.isInvalid())
return;
+ CheckNoDeref(Self, SrcExpr.get()->getType(), ResultType,
+ OpRange.getBegin());
}
}
}
@@ -2948,6 +2979,8 @@
// -Wcast-qual
DiagnoseCastQual(Op.Self, Op.SrcExpr, Op.DestType);
+ CheckNoDeref(*this, Op.SrcExpr.get()->getType(), Op.ResultType, LPLoc);
+
return Op.complete(CStyleCastExpr::Create(Context, Op.ResultType,
Op.ValueKind, Op.Kind, Op.SrcExpr.get(),
&Op.BasePath, CastTypeInfo, LPLoc, RPLoc));
Index: clang/include/clang/Sema/Initialization.h
===================================================================
--- clang/include/clang/Sema/Initialization.h
+++ clang/include/clang/Sema/Initialization.h
@@ -689,6 +689,9 @@
return Context >= IC_StaticCast;
}
+ /// Determine whether this initialization is a static cast.
+ bool isStaticCast() const { return Context == IC_StaticCast; }
+
/// Determine whether this initialization is a C-style cast.
bool isCStyleOrFunctionalCast() const {
return Context >= IC_CStyleCast;
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