leonardchan created this revision.
leonardchan added reviewers: aaron.ballman, rsmith.
leonardchan added a project: clang.
We find it more valuable to warn on all instances we're removing the `noderef`
attribute from a pointer. This patch removes the type holes where we initially
didn't warn on C-style casts. For instances where removing `noderef` is
intended, users can still disable the warning on line granularity with pragmas.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D84202
Files:
clang/lib/Sema/SemaCast.cpp
clang/test/Frontend/noderef.cpp
Index: clang/test/Frontend/noderef.cpp
===================================================================
--- clang/test/Frontend/noderef.cpp
+++ clang/test/Frontend/noderef.cpp
@@ -120,20 +120,18 @@
void cast_from_void_ptr(NODEREF void *x) {
int *a = static_cast<int *>(x); // expected-warning{{casting to
dereferenceable pointer removes 'noderef' attribute}}
- // Allow regular C-style casts and C-style through reinterpret_casts to be
holes
- int *b = reinterpret_cast<int *>(x);
- int *c = (int *)x;
+ int *b = reinterpret_cast<int *>(x); // expected-warning{{casting to
dereferenceable pointer removes 'noderef' attribute}}
+ int *c = (int *)x; // expected-warning{{casting to dereferenceable pointer
removes 'noderef' attribute}}
}
void conversion_sequences() {
NODEREF int *x;
int *x2 = x; // expected-warning{{casting to
dereferenceable pointer removes 'noderef' attribute}}
int *x3 = static_cast<int *>(x); // expected-warning{{casting to
dereferenceable pointer removes 'noderef' attribute}}
- int *x4 = reinterpret_cast<int *>(x);
// Functional cast - This is exactly equivalent to a C-style cast.
typedef int *INT_PTR;
- int *x5 = INT_PTR(x);
+ int *x5 = INT_PTR(x); // expected-warning{{casting to dereferenceable
pointer removes 'noderef' attribute}}
NODEREF Child *child;
Child *child2 = dynamic_cast<Child *>(child); // expected-warning{{casting
to dereferenceable pointer removes 'noderef' attribute}}
Index: clang/lib/Sema/SemaCast.cpp
===================================================================
--- clang/lib/Sema/SemaCast.cpp
+++ clang/lib/Sema/SemaCast.cpp
@@ -164,9 +164,9 @@
void CheckNoDeref(Sema &S, const QualType FromType, const QualType ToType,
SourceLocation OpLoc) {
- if (const auto *PtrType = dyn_cast<PointerType>(FromType)) {
+ if (const auto *PtrType = FromType->getAs<PointerType>()) {
if (PtrType->getPointeeType()->hasAttr(attr::NoDeref)) {
- if (const auto *DestType = dyn_cast<PointerType>(ToType)) {
+ if (const auto *DestType = ToType->getAs<PointerType>()) {
if (!DestType->getPointeeType()->hasAttr(attr::NoDeref)) {
S.Diag(OpLoc, diag::warn_noderef_to_dereferenceable_pointer);
}
@@ -1032,6 +1032,8 @@
/// like this:
/// char *bytes = reinterpret_cast\<char*\>(int_ptr);
void CastOperation::CheckReinterpretCast() {
+ CheckNoDerefRAII NoderefCheck(*this);
+
if (ValueKind == VK_RValue && !isPlaceholder(BuiltinType::Overload))
SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
else
@@ -2489,6 +2491,7 @@
void CastOperation::CheckCXXCStyleCast(bool FunctionalStyle,
bool ListInitialization) {
assert(Self.getLangOpts().CPlusPlus);
+ CheckNoDerefRAII NoderefCheck(*this);
// Handle placeholders.
if (isPlaceholder()) {
Index: clang/test/Frontend/noderef.cpp
===================================================================
--- clang/test/Frontend/noderef.cpp
+++ clang/test/Frontend/noderef.cpp
@@ -120,20 +120,18 @@
void cast_from_void_ptr(NODEREF void *x) {
int *a = static_cast<int *>(x); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
- // Allow regular C-style casts and C-style through reinterpret_casts to be holes
- int *b = reinterpret_cast<int *>(x);
- int *c = (int *)x;
+ int *b = reinterpret_cast<int *>(x); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
+ int *c = (int *)x; // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
}
void conversion_sequences() {
NODEREF int *x;
int *x2 = x; // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
int *x3 = static_cast<int *>(x); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
- int *x4 = reinterpret_cast<int *>(x);
// Functional cast - This is exactly equivalent to a C-style cast.
typedef int *INT_PTR;
- int *x5 = INT_PTR(x);
+ int *x5 = INT_PTR(x); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
NODEREF Child *child;
Child *child2 = dynamic_cast<Child *>(child); // expected-warning{{casting to dereferenceable pointer removes 'noderef' attribute}}
Index: clang/lib/Sema/SemaCast.cpp
===================================================================
--- clang/lib/Sema/SemaCast.cpp
+++ clang/lib/Sema/SemaCast.cpp
@@ -164,9 +164,9 @@
void CheckNoDeref(Sema &S, const QualType FromType, const QualType ToType,
SourceLocation OpLoc) {
- if (const auto *PtrType = dyn_cast<PointerType>(FromType)) {
+ if (const auto *PtrType = FromType->getAs<PointerType>()) {
if (PtrType->getPointeeType()->hasAttr(attr::NoDeref)) {
- if (const auto *DestType = dyn_cast<PointerType>(ToType)) {
+ if (const auto *DestType = ToType->getAs<PointerType>()) {
if (!DestType->getPointeeType()->hasAttr(attr::NoDeref)) {
S.Diag(OpLoc, diag::warn_noderef_to_dereferenceable_pointer);
}
@@ -1032,6 +1032,8 @@
/// like this:
/// char *bytes = reinterpret_cast\<char*\>(int_ptr);
void CastOperation::CheckReinterpretCast() {
+ CheckNoDerefRAII NoderefCheck(*this);
+
if (ValueKind == VK_RValue && !isPlaceholder(BuiltinType::Overload))
SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
else
@@ -2489,6 +2491,7 @@
void CastOperation::CheckCXXCStyleCast(bool FunctionalStyle,
bool ListInitialization) {
assert(Self.getLangOpts().CPlusPlus);
+ CheckNoDerefRAII NoderefCheck(*this);
// Handle placeholders.
if (isPlaceholder()) {
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