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[-Wunsafe-buffer-usage] Fix a small bug recently found #102953

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Merged
merged 1 commit into from
Aug 15, 2024
Merged

[-Wunsafe-buffer-usage] Fix a small bug recently found #102953

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14 changes: 7 additions & 7 deletions clang/lib/Analysis/UnsafeBufferUsage.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -402,9 +402,9 @@ AST_MATCHER(CXXConstructExpr, isSafeSpanTwoParamConstruct) {

QualType Arg0Ty = Arg0->IgnoreImplicit()->getType();

if (Arg0Ty->isConstantArrayType()) {
const APSInt ConstArrSize =
APSInt(cast<ConstantArrayType>(Arg0Ty)->getSize());
if (auto *ConstArrTy =
Finder->getASTContext().getAsConstantArrayType(Arg0Ty)) {
const APSInt ConstArrSize = APSInt(ConstArrTy->getSize());

// Check form 4:
return Arg1CV && APSInt::compareValues(ConstArrSize, *Arg1CV) == 0;
Expand Down Expand Up @@ -2659,7 +2659,7 @@ static FixItList fixVarDeclWithArray(const VarDecl *D, const ASTContext &Ctx,

// Note: the code below expects the declaration to not use any type sugar like
// typedef.
if (auto CAT = dyn_cast<clang::ConstantArrayType>(D->getType())) {
if (auto CAT = Ctx.getAsConstantArrayType(D->getType())) {
const QualType &ArrayEltT = CAT->getElementType();
assert(!ArrayEltT.isNull() && "Trying to fix a non-array type variable!");
// FIXME: support multi-dimensional arrays
Expand Down Expand Up @@ -2792,9 +2792,9 @@ fixVariable(const VarDecl *VD, FixitStrategy::Kind K,
return {};
}
case FixitStrategy::Kind::Array: {
if (VD->isLocalVarDecl() &&
isa<clang::ConstantArrayType>(VD->getType().getCanonicalType()))
return fixVariableWithArray(VD, Tracker, Ctx, Handler);
if (VD->isLocalVarDecl())
if (auto CAT = Ctx.getAsConstantArrayType(VD->getType()))
return fixVariableWithArray(VD, Tracker, Ctx, Handler);

DEBUG_NOTE_DECL_FAIL(VD, " : not a local const-size array");
return {};
Expand Down
3 changes: 3 additions & 0 deletions clang/test/SemaCXX/warn-unsafe-buffer-usage-in-container-span-construct.cpp
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Expand Up @@ -79,6 +79,8 @@ namespace construct_wt_ptr_size {
unsigned Y = 10;
std::span<int> S = std::span{&X, 1}; // no-warning
int Arr[10];
typedef int TenInts_t[10];
TenInts_t Arr2;

S = std::span{&X, 2}; // expected-warning{{the two-parameter std::span construction is unsafe as it can introduce mismatch between buffer size and the bound information}}
S = std::span{new int[10], 10}; // no-warning
Expand All @@ -90,6 +92,7 @@ namespace construct_wt_ptr_size {
S = std::span{new int[10], 9}; // expected-warning{{the two-parameter std::span construction is unsafe as it can introduce mismatch between buffer size and the bound information}} // not smart enough to tell its safe
S = std::span{new int[10], Y}; // expected-warning{{the two-parameter std::span construction is unsafe as it can introduce mismatch between buffer size and the bound information}} // not smart enough to tell its safe
S = std::span{Arr, 10}; // no-warning
S = std::span{Arr2, 10}; // no-warning
S = std::span{Arr, Y}; // expected-warning{{the two-parameter std::span construction is unsafe as it can introduce mismatch between buffer size and the bound information}} // not smart enough to tell its safe
S = std::span{p, 0}; // no-warning
}
Expand Down
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