[flang-commits] [flang] 7358c26 - [flang] Check for overflows in RESHAPE folding (#68342)
via flang-commits
flang-commits at lists.llvm.org
Mon Oct 30 10:25:25 PDT 2023
Author: Leandro Lupori
Date: 2023-10-30T14:25:21-03:00
New Revision: 7358c26d6acaa6c393623fde7cbc70372d0c67a8
URL: https://github.com/llvm/llvm-project/commit/7358c26d6acaa6c393623fde7cbc70372d0c67a8
DIFF: https://github.com/llvm/llvm-project/commit/7358c26d6acaa6c393623fde7cbc70372d0c67a8.diff
LOG: [flang] Check for overflows in RESHAPE folding (#68342)
TotalElementCount() was modified to return std::optional<uint64_t>,
where std::nullopt means overflow occurred. Besides the additional
check in RESHAPE folding, all callers of TotalElementCount() were
changed, to also check for overflows.
Added:
Modified:
flang/include/flang/Evaluate/constant.h
flang/include/flang/Evaluate/initial-image.h
flang/lib/Evaluate/constant.cpp
flang/lib/Evaluate/fold-designator.cpp
flang/lib/Evaluate/fold-implementation.h
flang/lib/Evaluate/initial-image.cpp
flang/lib/Semantics/data-to-inits.cpp
flang/test/Semantics/reshape.f90
Removed:
################################################################################
diff --git a/flang/include/flang/Evaluate/constant.h b/flang/include/flang/Evaluate/constant.h
index 04474e2f49a0f88..8c841918bccbe89 100644
--- a/flang/include/flang/Evaluate/constant.h
+++ b/flang/include/flang/Evaluate/constant.h
@@ -46,7 +46,8 @@ inline int GetRank(const ConstantSubscripts &s) {
return static_cast<int>(s.size());
}
-std::size_t TotalElementCount(const ConstantSubscripts &);
+// Returns the number of elements of shape, if no overflow occurs.
+std::optional<uint64_t> TotalElementCount(const ConstantSubscripts &shape);
// Validate dimension re-ordering like ORDER in RESHAPE.
// On success, return a vector that can be used as dimOrder in
diff --git a/flang/include/flang/Evaluate/initial-image.h b/flang/include/flang/Evaluate/initial-image.h
index e1f9a68acb00c20..dc9a9bfbfdf2203 100644
--- a/flang/include/flang/Evaluate/initial-image.h
+++ b/flang/include/flang/Evaluate/initial-image.h
@@ -22,7 +22,14 @@ namespace Fortran::evaluate {
class InitialImage {
public:
- enum Result { Ok, NotAConstant, OutOfRange, SizeMismatch, LengthMismatch };
+ enum Result {
+ Ok,
+ NotAConstant,
+ OutOfRange,
+ SizeMismatch,
+ LengthMismatch,
+ TooManyElems
+ };
explicit InitialImage(std::size_t bytes) : data_(bytes) {}
InitialImage(InitialImage &&that) = default;
@@ -60,7 +67,11 @@ class InitialImage {
if (offset < 0 || offset + bytes > data_.size()) {
return OutOfRange;
} else {
- auto elements{TotalElementCount(x.shape())};
+ auto optElements{TotalElementCount(x.shape())};
+ if (!optElements) {
+ return TooManyElems;
+ }
+ auto elements{*optElements};
auto elementBytes{bytes > 0 ? bytes / elements : 0};
if (elements * elementBytes != bytes) {
return SizeMismatch;
diff --git a/flang/lib/Evaluate/constant.cpp b/flang/lib/Evaluate/constant.cpp
index 0e0d412118d3bb2..a3bdefb76a414c0 100644
--- a/flang/lib/Evaluate/constant.cpp
+++ b/flang/lib/Evaluate/constant.cpp
@@ -80,8 +80,18 @@ ConstantSubscript ConstantBounds::SubscriptsToOffset(
return offset;
}
-std::size_t TotalElementCount(const ConstantSubscripts &shape) {
- return static_cast<std::size_t>(GetSize(shape));
+std::optional<uint64_t> TotalElementCount(const ConstantSubscripts &shape) {
+ uint64_t size{1};
+ for (auto dim : shape) {
+ CHECK(dim >= 0);
+ uint64_t osize{size};
+ size = osize * dim;
+ if (size > std::numeric_limits<decltype(dim)>::max() ||
+ (dim != 0 && size / dim != osize)) {
+ return std::nullopt;
+ }
+ }
+ return static_cast<uint64_t>(GetSize(shape));
}
bool ConstantBounds::IncrementSubscripts(
@@ -135,7 +145,7 @@ template <typename RESULT, typename ELEMENT>
ConstantBase<RESULT, ELEMENT>::ConstantBase(
std::vector<Element> &&x, ConstantSubscripts &&sh, Result res)
: ConstantBounds(std::move(sh)), result_{res}, values_(std::move(x)) {
- CHECK(size() == TotalElementCount(shape()));
+ CHECK(TotalElementCount(shape()) && size() == *TotalElementCount(shape()));
}
template <typename RESULT, typename ELEMENT>
@@ -149,7 +159,9 @@ bool ConstantBase<RESULT, ELEMENT>::operator==(const ConstantBase &that) const {
template <typename RESULT, typename ELEMENT>
auto ConstantBase<RESULT, ELEMENT>::Reshape(
const ConstantSubscripts &dims) const -> std::vector<Element> {
- std::size_t n{TotalElementCount(dims)};
+ std::optional<uint64_t> optN{TotalElementCount(dims)};
+ CHECK(optN);
+ uint64_t n{*optN};
CHECK(!empty() || n == 0);
std::vector<Element> elements;
auto iter{values().cbegin()};
@@ -209,7 +221,8 @@ template <int KIND>
Constant<Type<TypeCategory::Character, KIND>>::Constant(ConstantSubscript len,
std::vector<Scalar<Result>> &&strings, ConstantSubscripts &&sh)
: ConstantBounds(std::move(sh)), length_{len} {
- CHECK(strings.size() == TotalElementCount(shape()));
+ CHECK(TotalElementCount(shape()) &&
+ strings.size() == *TotalElementCount(shape()));
values_.assign(strings.size() * length_,
static_cast<typename Scalar<Result>::value_type>(' '));
ConstantSubscript at{0};
@@ -236,7 +249,9 @@ bool Constant<Type<TypeCategory::Character, KIND>>::empty() const {
template <int KIND>
std::size_t Constant<Type<TypeCategory::Character, KIND>>::size() const {
if (length_ == 0) {
- return TotalElementCount(shape());
+ std::optional<uint64_t> n{TotalElementCount(shape())};
+ CHECK(n);
+ return *n;
} else {
return static_cast<ConstantSubscript>(values_.size()) / length_;
}
@@ -274,7 +289,9 @@ auto Constant<Type<TypeCategory::Character, KIND>>::Substring(
template <int KIND>
auto Constant<Type<TypeCategory::Character, KIND>>::Reshape(
ConstantSubscripts &&dims) const -> Constant<Result> {
- std::size_t n{TotalElementCount(dims)};
+ std::optional<uint64_t> optN{TotalElementCount(dims)};
+ CHECK(optN);
+ uint64_t n{*optN};
CHECK(!empty() || n == 0);
std::vector<Element> elements;
ConstantSubscript at{0},
diff --git a/flang/lib/Evaluate/fold-designator.cpp b/flang/lib/Evaluate/fold-designator.cpp
index 7298b0a2fb10c56..6952436681f753c 100644
--- a/flang/lib/Evaluate/fold-designator.cpp
+++ b/flang/lib/Evaluate/fold-designator.cpp
@@ -373,7 +373,9 @@ ConstantObjectPointer ConstantObjectPointer::From(
FoldingContext &context, const Expr<SomeType> &expr) {
auto extents{GetConstantExtents(context, expr)};
CHECK(extents);
- std::size_t elements{TotalElementCount(*extents)};
+ std::optional<uint64_t> optElements{TotalElementCount(*extents)};
+ CHECK(optElements);
+ uint64_t elements{*optElements};
CHECK(elements > 0);
int rank{GetRank(*extents)};
ConstantSubscripts at(rank, 1);
diff --git a/flang/lib/Evaluate/fold-implementation.h b/flang/lib/Evaluate/fold-implementation.h
index 2a40018cd5a3865..868b7b6990fd384 100644
--- a/flang/lib/Evaluate/fold-implementation.h
+++ b/flang/lib/Evaluate/fold-implementation.h
@@ -492,7 +492,13 @@ Expr<TR> FoldElementalIntrinsicHelper(FoldingContext &context,
CHECK(rank == GetRank(shape));
// Compute all the scalar values of the results
std::vector<Scalar<TR>> results;
- if (TotalElementCount(shape) > 0) {
+ std::optional<uint64_t> n{TotalElementCount(shape)};
+ if (!n) {
+ context.messages().Say(
+ "Too many elements in elemental intrinsic function result"_err_en_US);
+ return Expr<TR>{std::move(funcRef)};
+ }
+ if (*n > 0) {
ConstantBounds bounds{shape};
ConstantSubscripts resultIndex(rank, 1);
ConstantSubscripts argIndex[]{std::get<I>(*args)->lbounds()...};
@@ -879,33 +885,40 @@ template <typename T> Expr<T> Folder<T>::RESHAPE(FunctionRef<T> &&funcRef) {
context_.messages().Say(
"'shape=' argument must not have a negative extent"_err_en_US);
} else {
- int rank{GetRank(shape.value())};
- std::size_t resultElements{TotalElementCount(shape.value())};
- std::optional<std::vector<int>> dimOrder;
- if (order) {
- dimOrder = ValidateDimensionOrder(rank, *order);
- }
- std::vector<int> *dimOrderPtr{dimOrder ? &dimOrder.value() : nullptr};
- if (order && !dimOrder) {
- context_.messages().Say("Invalid 'order=' argument in RESHAPE"_err_en_US);
- } else if (resultElements > source->size() && (!pad || pad->empty())) {
+ std::optional<uint64_t> optResultElement{TotalElementCount(shape.value())};
+ if (!optResultElement) {
context_.messages().Say(
- "Too few elements in 'source=' argument and 'pad=' "
- "argument is not present or has null size"_err_en_US);
+ "'shape=' argument has too many elements"_err_en_US);
} else {
- Constant<T> result{!source->empty() || !pad
- ? source->Reshape(std::move(shape.value()))
- : pad->Reshape(std::move(shape.value()))};
- ConstantSubscripts subscripts{result.lbounds()};
- auto copied{result.CopyFrom(*source,
- std::min(source->size(), resultElements), subscripts, dimOrderPtr)};
- if (copied < resultElements) {
- CHECK(pad);
- copied += result.CopyFrom(
- *pad, resultElements - copied, subscripts, dimOrderPtr);
+ int rank{GetRank(shape.value())};
+ uint64_t resultElements{*optResultElement};
+ std::optional<std::vector<int>> dimOrder;
+ if (order) {
+ dimOrder = ValidateDimensionOrder(rank, *order);
+ }
+ std::vector<int> *dimOrderPtr{dimOrder ? &dimOrder.value() : nullptr};
+ if (order && !dimOrder) {
+ context_.messages().Say(
+ "Invalid 'order=' argument in RESHAPE"_err_en_US);
+ } else if (resultElements > source->size() && (!pad || pad->empty())) {
+ context_.messages().Say(
+ "Too few elements in 'source=' argument and 'pad=' "
+ "argument is not present or has null size"_err_en_US);
+ } else {
+ Constant<T> result{!source->empty() || !pad
+ ? source->Reshape(std::move(shape.value()))
+ : pad->Reshape(std::move(shape.value()))};
+ ConstantSubscripts subscripts{result.lbounds()};
+ auto copied{result.CopyFrom(*source,
+ std::min(source->size(), resultElements), subscripts, dimOrderPtr)};
+ if (copied < resultElements) {
+ CHECK(pad);
+ copied += result.CopyFrom(
+ *pad, resultElements - copied, subscripts, dimOrderPtr);
+ }
+ CHECK(copied == resultElements);
+ return Expr<T>{std::move(result)};
}
- CHECK(copied == resultElements);
- return Expr<T>{std::move(result)};
}
}
// Invalid, prevent re-folding
@@ -944,14 +957,19 @@ template <typename T> Expr<T> Folder<T>::SPREAD(FunctionRef<T> &&funcRef) {
ConstantSubscripts shape{source->shape()};
shape.insert(shape.begin() + *dim - 1, *ncopies);
Constant<T> spread{source->Reshape(std::move(shape))};
- std::vector<int> dimOrder;
- for (int j{0}; j < sourceRank; ++j) {
- dimOrder.push_back(j < *dim - 1 ? j : j + 1);
- }
- dimOrder.push_back(*dim - 1);
- ConstantSubscripts at{spread.lbounds()}; // all 1
- spread.CopyFrom(*source, TotalElementCount(spread.shape()), at, &dimOrder);
- return Expr<T>{std::move(spread)};
+ std::optional<uint64_t> n{TotalElementCount(spread.shape())};
+ if (!n) {
+ context_.messages().Say("Too many elements in SPREAD result"_err_en_US);
+ } else {
+ std::vector<int> dimOrder;
+ for (int j{0}; j < sourceRank; ++j) {
+ dimOrder.push_back(j < *dim - 1 ? j : j + 1);
+ }
+ dimOrder.push_back(*dim - 1);
+ ConstantSubscripts at{spread.lbounds()}; // all 1
+ spread.CopyFrom(*source, *n, at, &dimOrder);
+ return Expr<T>{std::move(spread)};
+ }
}
// Invalid, prevent re-folding
return MakeInvalidIntrinsic(std::move(funcRef));
diff --git a/flang/lib/Evaluate/initial-image.cpp b/flang/lib/Evaluate/initial-image.cpp
index a0fe4ec95da94d7..3b0d738c422d4f4 100644
--- a/flang/lib/Evaluate/initial-image.cpp
+++ b/flang/lib/Evaluate/initial-image.cpp
@@ -18,7 +18,11 @@ auto InitialImage::Add(ConstantSubscript offset, std::size_t bytes,
if (offset < 0 || offset + bytes > data_.size()) {
return OutOfRange;
} else {
- auto elements{TotalElementCount(x.shape())};
+ auto optElements{TotalElementCount(x.shape())};
+ if (!optElements) {
+ return TooManyElems;
+ }
+ auto elements{*optElements};
auto elementBytes{bytes > 0 ? bytes / elements : 0};
if (elements * elementBytes != bytes) {
return SizeMismatch;
@@ -89,7 +93,9 @@ class AsConstantHelper {
}
using Const = Constant<T>;
using Scalar = typename Const::Element;
- std::size_t elements{TotalElementCount(extents_)};
+ std::optional<uint64_t> optElements{TotalElementCount(extents_)};
+ CHECK(optElements);
+ uint64_t elements{*optElements};
std::vector<Scalar> typedValue(elements);
auto elemBytes{ToInt64(type_.MeasureSizeInBytes(
context_, GetRank(extents_) > 0, charLength_))};
diff --git a/flang/lib/Semantics/data-to-inits.cpp b/flang/lib/Semantics/data-to-inits.cpp
index bc2d8147e91b556..86f5f399310c0f3 100644
--- a/flang/lib/Semantics/data-to-inits.cpp
+++ b/flang/lib/Semantics/data-to-inits.cpp
@@ -462,6 +462,8 @@ bool DataInitializationCompiler<DSV>::InitElement(
"DATA statement value '%s' for '%s' has the wrong length"_warn_en_US,
folded.AsFortran(), DescribeElement());
return true;
+ } else if (status == evaluate::InitialImage::TooManyElems) {
+ exprAnalyzer_.Say("DATA statement has too many elements"_err_en_US);
} else {
CHECK(exprAnalyzer_.context().AnyFatalError());
}
diff --git a/flang/test/Semantics/reshape.f90 b/flang/test/Semantics/reshape.f90
index fb5e0023e2716e8..ea302ceed66aad8 100644
--- a/flang/test/Semantics/reshape.f90
+++ b/flang/test/Semantics/reshape.f90
@@ -49,6 +49,10 @@ program reshaper
integer, parameter :: array21(I64_MAX - 2 : I64_MAX) = [1, 2, 3]
integer, parameter :: array22(2) = RESHAPE(array21, [2])
+ integer(8), parameter :: huge_shape(2) = [I64_MAX, I64_MAX]
+ !ERROR: 'shape=' argument has too many elements
+ integer :: array23(I64_MAX, I64_MAX) = RESHAPE([1, 2, 3], huge_shape)
+
!ERROR: Size of 'shape=' argument must not be greater than 15
CALL ext_sub(RESHAPE([(n, n=1,20)], &
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]))
More information about the flang-commits
mailing list