Skip to content

[WebKit checkers] Treat std::bit_cast as a pointer conversion #137476

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
May 1, 2025
Merged

[WebKit checkers] Treat std::bit_cast as a pointer conversion #137476

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
c76e861
[WebKit checkers] Treat std::bit_cast as a pointer conversion
rniwa Apr 26, 2025
49f3566
Also fix TrivialFunctionAnalysisVisitor to recognize std::bit_cast as…
rniwa Apr 30, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 6 additions & 2 deletions clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -462,7 +462,7 @@ bool isPtrConversion(const FunctionDecl *F) {
const auto FunctionName = safeGetName(F);
if (FunctionName == "getPtr" || FunctionName == "WeakPtr" ||
FunctionName == "dynamicDowncast" || FunctionName == "downcast" ||
FunctionName == "checkedDowncast" ||
FunctionName == "checkedDowncast" || FunctionName == "bit_cast" ||
FunctionName == "uncheckedDowncast" || FunctionName == "bitwise_cast" ||
FunctionName == "bridge_cast" || FunctionName == "bridge_id_cast" ||
FunctionName == "dynamic_cf_cast" || FunctionName == "checked_cf_cast" ||
Expand Down Expand Up @@ -645,6 +645,10 @@ class TrivialFunctionAnalysisVisitor
auto *Callee = CE->getDirectCallee();
if (!Callee)
return false;

if (isPtrConversion(Callee))
return true;

const auto &Name = safeGetName(Callee);

if (Callee->isInStdNamespace() &&
Expand All @@ -658,7 +662,7 @@ class TrivialFunctionAnalysisVisitor
Name == "isMainThreadOrGCThread" || Name == "isMainRunLoop" ||
Name == "isWebThread" || Name == "isUIThread" ||
Name == "mayBeGCThread" || Name == "compilerFenceForCrash" ||
Name == "bitwise_cast" || isTrivialBuiltinFunction(Callee))
isTrivialBuiltinFunction(Callee))
return true;

return IsFunctionTrivial(Callee);
Expand Down
8 changes: 4 additions & 4 deletions clang/test/Analysis/Checkers/WebKit/call-args-checked-ptr.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -173,14 +173,14 @@ namespace param_formarding_function {

namespace casts {

CheckedObj* downcast(CheckedObj*) { return nullptr; }

template<class T>
T* bitwise_cast(T*) { return nullptr; }
CheckedObj* downcast(CheckedObj*);
template<class T> T* bitwise_cast(T*);
template<class T> T* bit_cast(T*);

void foo(CheckedObj* param) {
consume_ref_countable_ptr(downcast(param));
consume_ref_countable_ptr(bitwise_cast(param));
consume_ref_countable_ptr(bit_cast(param));
}
}
}
Expand Down
18 changes: 9 additions & 9 deletions clang/test/Analysis/Checkers/WebKit/call-args.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -173,15 +173,15 @@ namespace param_formarding_function {

namespace casts {

RefCountable* downcast(RefCountable*) { return nullptr; }

template<class T>
T* bitwise_cast(T*) { return nullptr; }

void foo(RefCountable* param) {
consume_ref_countable_ptr(downcast(param));
consume_ref_countable_ptr(bitwise_cast(param));
}
RefCountable* downcast(RefCountable*);
template<class T> T* bitwise_cast(T*);
template<class T> T* bit_cast(T*);

void foo(RefCountable* param) {
consume_ref_countable_ptr(downcast(param));
consume_ref_countable_ptr(bitwise_cast(param));
consume_ref_countable_ptr(bit_cast(param));
}
}
}

Expand Down
14 changes: 14 additions & 0 deletions clang/test/Analysis/Checkers/WebKit/uncounted-local-vars.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -205,6 +205,20 @@ void foo2() {
}
} // namespace guardian_casts

namespace casts {

RefCountable* provide() { return nullptr; }
RefCountable* downcast(RefCountable*);
template<class T> T* bitwise_cast(T*);
template<class T> T* bit_cast(T*);

void foo() {
auto* cast1 = downcast(provide());
auto* cast2 = bitwise_cast(provide());
auto* cast3 = bit_cast(provide());
}
} // namespace casts

namespace guardian_ref_conversion_operator {
void foo() {
Ref<RefCountable> rc;
Expand Down
5 changes: 5 additions & 0 deletions clang/test/Analysis/Checkers/WebKit/uncounted-obj-arg.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -77,6 +77,9 @@ T&& forward(T& arg);
template<typename T>
T&& move( T&& t );

template<typename ToType, typename FromType>
ToType bit_cast(FromType from);

#define offsetof(t, d) __builtin_offsetof(t, d)

} // namespace std
Expand Down Expand Up @@ -386,6 +389,7 @@ class RefCounted {
void trivial68() { point pt = { 1.0 }; }
unsigned trivial69() { return offsetof(OtherObj, children); }
DerivedNumber* trivial70() { [[clang::suppress]] return static_cast<DerivedNumber*>(number); }
unsigned trivial71() { return std::bit_cast<unsigned>(nullptr); }

static RefCounted& singleton() {
static RefCounted s_RefCounted;
Expand Down Expand Up @@ -577,6 +581,7 @@ class UnrelatedClass {
getFieldTrivial().trivial68(); // no-warning
getFieldTrivial().trivial69(); // no-warning
getFieldTrivial().trivial70(); // no-warning
getFieldTrivial().trivial71(); // no-warning

RefCounted::singleton().trivial18(); // no-warning
RefCounted::singleton().someFunction(); // no-warning
Expand Down