CNA-BUG-067: Math argument failures throw a mix of Sharp Runtime and std:: exception types that differs between near-identical functions

CNA snapshot 009d40f5  ·  Known Issues › Current bugs  ·  source links pinned to 009d40f5

BoundingBox throws Sharp Runtime ArgumentException types as XNA does, but BoundingSphere::CreateFromPoints, BoundingFrustum::GetCorners and the perspective builders throw std::invalid_argument or std::out_of_range.

Identifier

CNA-BUG-067

Category

Bug

Subsystem

Math & geometry

Status

Open

Verified against

CNA 009d40f5 (009d40f5dd085c4e674d3479675fac84b12b3e0a)

Severity

Low (a triage suggestion, not a project priority)

Evidence basis

Source-verified: read at TARGET, not executed

Tests touching this area

Yes: see Current tests

Affected contract

The exception types thrown by the math module's argument checks (CreateFromPoints, GetCorners, the Matrix::CreatePerspective* builders and the indexed overloads)

Expected behaviour

XNA 4.0 throws the ArgumentException family for these argument errors (for example ArgumentOutOfRangeException from CreatePerspectiveFieldOfView, read from its IL). CNA's own CHECKLIST.md records System::ArgumentOutOfRangeException as the majority precedent for out-of-range indexers and lists the std::out_of_range outliers as a known, unresolved inconsistency.

Actual behaviour at TARGET

• BoundingBox::CreateFromPoints (empty list): System::ArgumentException; BoundingBox::GetCorners(std::vector<Vector3>&) (fewer than eight): System::ArgumentOutOfRangeException.
• BoundingSphere::CreateFromPoints (empty list): std::invalid_argument; BoundingFrustum::GetCorners(std::vector<Vector3>&): std::out_of_range.
• The ten guards in Matrix::CreatePerspective, CreatePerspectiveFieldOfView and CreatePerspectiveOffCenter: std::invalid_argument.
• The array overloads of Vector2/3/4::Transform and TransformNormal, Curve::ComputeTangent and the CurveKeyCollection index checks: std::out_of_range.

Sharp Runtime's System::ArgumentException derives from System::SystemException and System::Exception, i.e. from std::exception but not from std::invalid_argument (next at 41b918c9, not pinned by TARGET), so no single catch clause short of std::exception handles a math argument error. The C ABI maps all of them to CNA_RESULT_INVALID_ARGUMENT, with category RANGE for std::out_of_range and ARGUMENT for the others.

Source locations

• modules/math/src/BoundingBox.cpp — BoundingBox::CreateFromPoints and BoundingBox::GetCorners(std::vector<Vector3>&)
• modules/math/src/BoundingSphere.cpp — BoundingSphere::CreateFromPoints: std::invalid_argument
• modules/math/src/BoundingFrustum.cpp — BoundingFrustum::GetCorners(std::vector<Vector3>&): std::out_of_range
• modules/math/src/Matrix.cpp — the CreatePerspective* guards: std::invalid_argument
• CHECKLIST.md — the mixed out-of-range precedent recorded as a known, unresolved inconsistency
• modules/c-api/src/CnaCApiDetail.hpp — CallWithExceptionBarrier: the result and category per exception family

Evidence

Checked by reading at 009d40f5; nothing was built or executed for this entry. Every throw in modules/math/src was listed and classified; the tests assert each current type from both sides (BoundingBoxTests the System types, BoundingSphereTests, BoundingFrustumTests and MatrixTests the std types).

Focused reproduction

Illustrative; not compiled or run for this entry.

std::vector<Vector3> none;
try { BoundingBox::CreateFromPoints(none); }    catch (const System::ArgumentException&) { /* caught */ }
try { BoundingSphere::CreateFromPoints(none); } catch (const System::ArgumentException&) { /* not caught: std::invalid_argument */ }

Current tests

BoundingBoxTests.cpp expects System::ArgumentException and System::ArgumentOutOfRangeException; BoundingSphereTests.cpp expects std::invalid_argument; BoundingFrustumTests.cpp expects std::out_of_range; MatrixTests.cpp expects std::invalid_argument. The inconsistency is therefore pinned, not merely untested.

Regression test

Choose one family per XNA contract (the Sharp Runtime ArgumentException family, as CHECKLIST.md's majority precedent suggests), change the throw sites and the four suites' expectations together, and add C ABI checks that the result category stays stable.

Blast radius

C++ callers that catch a specific exception type around these functions. The C ABI result code is the same for every family; only the error category differs. Normal inputs are unaffected.

Workaround

Catch std::exception (or both families) around math calls that validate their arguments.