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🍒 [-Wunsafe-buffer-usage] Handle more null pointer constants #11754

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Merged
merged 1 commit into from
Nov 5, 2025
Merged

🍒 [-Wunsafe-buffer-usage] Handle more null pointer constants #11754

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3 changes: 2 additions & 1 deletion clang/lib/Analysis/UnsafeBufferUsage.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1028,7 +1028,8 @@ static bool isCountAttributedPointerArgumentSafeImpl(
PtrArgNoImp = DAE->getExpr()->IgnoreParenImpCasts();

// check form 0:
if (PtrArgNoImp->getType()->isNullPtrType()) {
if (PtrArgNoImp->isNullPointerConstant(Context,
Expr::NPC_ValueDependentIsNotNull)) {
if (isOrNull)
return true;
if (CountArg)
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20 changes: 19 additions & 1 deletion clang/test/SemaCXX/warn-unsafe-buffer-usage-count-attributed-pointer-argument.cpp
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Expand Up @@ -81,7 +81,7 @@ void cb_cint_42(const int *__counted_by(42) p);
// expected-note@+1 6{{consider using 'std::span' and passing '.first(...).data()' to the parameter 'p'}}
void cb_cint_multi(const int *__counted_by((a + b) * (c - d)) p, int a, int b, int c, int d);

// expected-note@+1 3{{consider using a safe container and passing '.data()' to the parameter 'p' and '.size()' to its dependent parameter 'size' or 'std::span' and passing '.first(...).data()' to the parameter 'p'}}
// expected-note@+1 +{{consider using a safe container and passing '.data()' to the parameter 'p' and '.size()' to its dependent parameter 'size' or 'std::span' and passing '.first(...).data()' to the parameter 'p'}}
void sb_void(void *__sized_by(size) p, size_t size);

// expected-note@+1 13{{consider using a safe container and passing '.data()' to the parameter 'p' and '.size()' to its dependent parameter 'size' or 'std::span' and passing '.first(...).data()' to the parameter 'p'}}
Expand Down Expand Up @@ -416,6 +416,24 @@ void nullptr_as_arg(size_t n) {
sbn_void(nullptr, n);
}

void zero_as_arg(size_t n) {
cb_int(0, 0);
cb_int(0, 42); // expected-warning{{unsafe assignment to function parameter of count-attributed type}}
cb_int(0, n); // expected-warning{{unsafe assignment to function parameter of count-attributed type}}

sb_void(0, 0);
sb_void(0, 42); // expected-warning{{unsafe assignment to function parameter of count-attributed type}}
sb_void(0, n); // expected-warning{{unsafe assignment to function parameter of count-attributed type}}

cbn_int(0, 0);
cbn_int(0, 42);
cbn_int(0, n);

sbn_void(0, 0);
sbn_void(0, 42);
sbn_void(0, n);
}

void single_variable() {
int Var;
int Arr[10];
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