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// Copyright 2020 The Dawn & Tint Authors
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "src/tint/lang/wgsl/resolver/validator.h"
#include <algorithm>
#include <bitset>
#include <limits>
#include <string_view>
#include <tuple>
#include <utility>
#include "src/tint/lang/core/fluent_types.h"
#include "src/tint/lang/core/parameter_usage.h"
#include "src/tint/lang/core/type/abstract_numeric.h"
#include "src/tint/lang/core/type/atomic.h"
#include "src/tint/lang/core/type/depth_multisampled_texture.h"
#include "src/tint/lang/core/type/depth_texture.h"
#include "src/tint/lang/core/type/input_attachment.h"
#include "src/tint/lang/core/type/multisampled_texture.h"
#include "src/tint/lang/core/type/pointer.h"
#include "src/tint/lang/core/type/reference.h"
#include "src/tint/lang/core/type/sampled_texture.h"
#include "src/tint/lang/core/type/sampler.h"
#include "src/tint/lang/core/type/storage_texture.h"
#include "src/tint/lang/core/type/texture_dimension.h"
#include "src/tint/lang/wgsl/ast/alias.h"
#include "src/tint/lang/wgsl/ast/assignment_statement.h"
#include "src/tint/lang/wgsl/ast/blend_src_attribute.h"
#include "src/tint/lang/wgsl/ast/break_statement.h"
#include "src/tint/lang/wgsl/ast/call_statement.h"
#include "src/tint/lang/wgsl/ast/continue_statement.h"
#include "src/tint/lang/wgsl/ast/disable_validation_attribute.h"
#include "src/tint/lang/wgsl/ast/discard_statement.h"
#include "src/tint/lang/wgsl/ast/for_loop_statement.h"
#include "src/tint/lang/wgsl/ast/id_attribute.h"
#include "src/tint/lang/wgsl/ast/if_statement.h"
#include "src/tint/lang/wgsl/ast/internal_attribute.h"
#include "src/tint/lang/wgsl/ast/interpolate_attribute.h"
#include "src/tint/lang/wgsl/ast/loop_statement.h"
#include "src/tint/lang/wgsl/ast/return_statement.h"
#include "src/tint/lang/wgsl/ast/switch_statement.h"
#include "src/tint/lang/wgsl/ast/traverse_expressions.h"
#include "src/tint/lang/wgsl/ast/unary_op_expression.h"
#include "src/tint/lang/wgsl/ast/variable_decl_statement.h"
#include "src/tint/lang/wgsl/ast/workgroup_attribute.h"
#include "src/tint/lang/wgsl/builtin_fn.h"
#include "src/tint/lang/wgsl/sem/array.h"
#include "src/tint/lang/wgsl/sem/break_if_statement.h"
#include "src/tint/lang/wgsl/sem/call.h"
#include "src/tint/lang/wgsl/sem/for_loop_statement.h"
#include "src/tint/lang/wgsl/sem/function.h"
#include "src/tint/lang/wgsl/sem/if_statement.h"
#include "src/tint/lang/wgsl/sem/loop_statement.h"
#include "src/tint/lang/wgsl/sem/materialize.h"
#include "src/tint/lang/wgsl/sem/member_accessor_expression.h"
#include "src/tint/lang/wgsl/sem/statement.h"
#include "src/tint/lang/wgsl/sem/struct.h"
#include "src/tint/lang/wgsl/sem/switch_statement.h"
#include "src/tint/lang/wgsl/sem/value_constructor.h"
#include "src/tint/lang/wgsl/sem/value_conversion.h"
#include "src/tint/lang/wgsl/sem/variable.h"
#include "src/tint/lang/wgsl/sem/while_statement.h"
#include "src/tint/utils/containers/map.h"
#include "src/tint/utils/containers/reverse.h"
#include "src/tint/utils/containers/transform.h"
#include "src/tint/utils/macros/defer.h"
#include "src/tint/utils/macros/scoped_assignment.h"
#include "src/tint/utils/math/math.h"
#include "src/tint/utils/text/string.h"
#include "src/tint/utils/text/string_stream.h"
#include "src/tint/utils/text/styled_text.h"
#include "src/tint/utils/text/text_style.h"
using namespace tint::core::fluent_types; // NOLINT
namespace tint::resolver {
namespace {
constexpr size_t kMaxFunctionParameters = 255;
constexpr size_t kMaxSwitchCaseSelectors = 16383;
constexpr size_t kMaxClipDistancesSize = 8;
bool IsValidStorageTextureDimension(core::type::TextureDimension dim) {
switch (dim) {
case core::type::TextureDimension::k1d:
case core::type::TextureDimension::k2d:
case core::type::TextureDimension::k2dArray:
case core::type::TextureDimension::k3d:
return true;
default:
return false;
}
}
bool IsValidStorageTextureTexelFormat(core::TexelFormat format) {
switch (format) {
case core::TexelFormat::kBgra8Unorm:
case core::TexelFormat::kR32Float:
case core::TexelFormat::kR32Sint:
case core::TexelFormat::kR32Uint:
case core::TexelFormat::kR8Unorm:
case core::TexelFormat::kRg32Float:
case core::TexelFormat::kRg32Sint:
case core::TexelFormat::kRg32Uint:
case core::TexelFormat::kRgba16Float:
case core::TexelFormat::kRgba16Sint:
case core::TexelFormat::kRgba16Uint:
case core::TexelFormat::kRgba32Float:
case core::TexelFormat::kRgba32Sint:
case core::TexelFormat::kRgba32Uint:
case core::TexelFormat::kRgba8Sint:
case core::TexelFormat::kRgba8Snorm:
case core::TexelFormat::kRgba8Uint:
case core::TexelFormat::kRgba8Unorm:
return true;
default:
return false;
}
}
template <typename CALLBACK>
void TraverseCallChain(const sem::Function* from, const sem::Function* to, CALLBACK&& callback) {
for (auto* f : from->TransitivelyCalledFunctions()) {
if (f == to) {
callback(f);
return;
}
if (f->TransitivelyCalledFunctions().Contains(to)) {
TraverseCallChain(f, to, callback);
callback(f);
return;
}
}
TINT_ICE() << "TraverseCallChain() 'from' does not transitively call 'to'";
}
} // namespace
Validator::Validator(
ProgramBuilder* builder,
SemHelper& sem,
const wgsl::Extensions& enabled_extensions,
const wgsl::AllowedFeatures& allowed_features,
const wgsl::ValidationMode mode,
const Hashmap<const core::type::Type*, const Source*, 8>& atomic_composite_info,
Hashset<TypeAndAddressSpace, 8>& valid_type_storage_layouts)
: symbols_(builder->Symbols()),
diagnostics_(builder->Diagnostics()),
sem_(sem),
enabled_extensions_(enabled_extensions),
allowed_features_(allowed_features),
mode_(mode),
atomic_composite_info_(atomic_composite_info),
valid_type_storage_layouts_(valid_type_storage_layouts) {
// Set default severities for filterable diagnostic rules.
diagnostic_filters_.Set(wgsl::CoreDiagnosticRule::kDerivativeUniformity,
wgsl::DiagnosticSeverity::kError);
diagnostic_filters_.Set(wgsl::ChromiumDiagnosticRule::kUnreachableCode,
wgsl::DiagnosticSeverity::kWarning);
}
Validator::~Validator() = default;
diag::Diagnostic& Validator::AddError(const Source& source) const {
return diagnostics_.AddError(source);
}
diag::Diagnostic& Validator::AddWarning(const Source& source) const {
return diagnostics_.AddWarning(source);
}
diag::Diagnostic& Validator::AddNote(const Source& source) const {
return diagnostics_.AddNote(source);
}
diag::Diagnostic* Validator::MaybeAddDiagnostic(wgsl::DiagnosticRule rule,
const Source& source) const {
auto severity = diagnostic_filters_.Get(rule);
if (severity != wgsl::DiagnosticSeverity::kOff) {
diag::Diagnostic d{};
d.severity = ToSeverity(severity);
d.source = source;
return &diagnostics_.Add(std::move(d));
}
return nullptr;
}
// https://gpuweb.github.io/gpuweb/wgsl/#plain-types-section
bool Validator::IsPlain(const core::type::Type* type) const {
return type->IsAnyOf<core::type::Scalar, core::type::Atomic, core::type::Vector,
core::type::Matrix, sem::Array, core::type::Struct>();
}
// https://gpuweb.github.io/gpuweb/wgsl/#fixed-footprint-types
bool Validator::IsFixedFootprint(const core::type::Type* type) const {
return Switch(
type, //
[&](const core::type::Vector*) { return true; }, //
[&](const core::type::Matrix*) { return true; }, //
[&](const core::type::Atomic*) { return true; },
[&](const sem::Array* arr) {
return !arr->Count()->Is<core::type::RuntimeArrayCount>() &&
IsFixedFootprint(arr->ElemType());
},
[&](const core::type::Struct* str) {
for (auto* member : str->Members()) {
if (!IsFixedFootprint(member->Type())) {
return false;
}
}
return true;
},
[&](Default) { return type->Is<core::type::Scalar>(); });
}
// https://gpuweb.github.io/gpuweb/wgsl.html#host-shareable-types
bool Validator::IsHostShareable(const core::type::Type* type) const {
if (type->IsAnyOf<core::type::I32, core::type::U32, core::type::F32, core::type::F16>()) {
return true;
}
return Switch(
type, //
[&](const core::type::Vector* vec) { return IsHostShareable(vec->Type()); },
[&](const core::type::Matrix* mat) { return IsHostShareable(mat->Type()); },
[&](const sem::Array* arr) { return IsHostShareable(arr->ElemType()); },
[&](const core::type::Struct* str) {
for (auto* member : str->Members()) {
if (!IsHostShareable(member->Type())) {
return false;
}
}
return true;
},
[&](const core::type::Atomic* atomic) { return IsHostShareable(atomic->Type()); });
}
// https://gpuweb.github.io/gpuweb/wgsl.html#storable-types
bool Validator::IsStorable(const core::type::Type* type) const {
return IsPlain(type) || type->IsAnyOf<core::type::Texture, core::type::Sampler>();
}
const ast::Statement* Validator::ClosestContinuing(bool stop_at_loop,
bool stop_at_switch,
sem::Statement* current_statement) const {
for (const auto* s = current_statement; s != nullptr; s = s->Parent()) {
if (stop_at_loop && s->Is<sem::LoopStatement>()) {
break;
}
if (stop_at_switch && s->Is<sem::SwitchStatement>()) {
break;
}
if (s->Is<sem::LoopContinuingBlockStatement>()) {
return s->Declaration();
}
if (auto* f = As<sem::ForLoopStatement>(s->Parent())) {
if (f->Declaration()->continuing == s->Declaration()) {
return s->Declaration();
}
if (stop_at_loop) {
break;
}
}
if (Is<sem::WhileStatement>(s->Parent())) {
if (stop_at_loop) {
break;
}
}
}
return nullptr;
}
bool Validator::Enables(VectorRef<const ast::Enable*> enables) const {
auto source_of = [&](wgsl::Extension ext) {
for (auto* enable : enables) {
for (auto* extension : enable->extensions) {
if (extension->name == ext) {
return extension->source;
}
}
}
return Source{};
};
// List of extensions that cannot be used together.
std::pair<wgsl::Extension, wgsl::Extension> incompatible[] = {
{
wgsl::Extension::kChromiumExperimentalPixelLocal,
wgsl::Extension::kChromiumExperimentalFramebufferFetch,
},
};
for (auto pair : incompatible) {
if (enabled_extensions_.Contains(pair.first) && enabled_extensions_.Contains(pair.second)) {
AddError(source_of(pair.first))
<< "extension " << style::Code(pair.first) << " cannot be used with extension "
<< style::Code(pair.second);
AddNote(source_of(pair.second)) << style::Code(pair.second) << " enabled here";
return false;
}
}
if (enabled_extensions_.Contains(wgsl::Extension::kSubgroupsF16)) {
if (!enabled_extensions_.Contains(wgsl::Extension::kSubgroups)) {
AddError(source_of(wgsl::Extension::kSubgroupsF16))
<< "extension " << style::Code("subgroups_f16")
<< " cannot be used without extension " << style::Code("subgroups");
return false;
}
if (!enabled_extensions_.Contains(wgsl::Extension::kF16)) {
AddError(source_of(wgsl::Extension::kSubgroupsF16))
<< "extension " << style::Code("subgroups_f16")
<< " cannot be used without extension " << style::Code("f16");
return false;
}
}
return true;
}
bool Validator::Atomic(const ast::TemplatedIdentifier* a, const core::type::Atomic* s) const {
// https://gpuweb.github.io/gpuweb/wgsl/#atomic-types
// T must be either u32 or i32.
if (!s->Type()->IsAnyOf<core::type::U32, core::type::I32>()) {
AddError(a->arguments[0]->source)
<< style::Type("atomic") << " only supports " << style::Type("i32") << " or "
<< style::Type("u32") << " types";
return false;
}
return true;
}
bool Validator::Pointer(const ast::TemplatedIdentifier* a, const core::type::Pointer* s) const {
if (s->AddressSpace() == core::AddressSpace::kUndefined) {
AddError(a->source) << "ptr missing address space";
return false;
}
if (s->AddressSpace() != core::AddressSpace::kHandle) {
if (s->StoreType()->Is<core::type::Texture>()) {
AddError(a->source) << "pointer can not be formed to a texture";
return false;
} else if (s->StoreType()->Is<core::type::Sampler>()) {
AddError(a->source) << "pointer can not be formed to a sampler";
return false;
}
}
if (a->arguments.Length() > 2) { // ptr<address-space, type [, access]>
// https://www.w3.org/TR/WGSL/#access-mode-defaults
// When writing a variable declaration or a pointer type in WGSL source:
// * For the storage address space, the access mode is optional, and defaults to read.
// * For other address spaces, the access mode must not be written.
if (s->AddressSpace() != core::AddressSpace::kStorage) {
AddError(a->source)
<< "only pointers in <storage> address space may specify an access mode";
return false;
}
}
if (auto* store_ty = s->StoreType(); !IsStorable(store_ty)) {
AddError(a->arguments[1]->source)
<< sem_.TypeNameOf(store_ty) + " cannot be used as the store type of a pointer";
return false;
}
return CheckTypeAccessAddressSpace(s->StoreType(), s->Access(), s->AddressSpace(), tint::Empty,
a->source);
}
bool Validator::StorageTexture(const core::type::StorageTexture* t, const Source& source) const {
switch (t->Access()) {
case core::Access::kRead:
if (!allowed_features_.features.count(
wgsl::LanguageFeature::kReadonlyAndReadwriteStorageTextures)) {
AddError(source) << "read-only storage textures require the "
"readonly_and_readwrite_storage_textures language feature, "
"which is not allowed in the current environment";
return false;
}
break;
case core::Access::kReadWrite:
if (!allowed_features_.features.count(
wgsl::LanguageFeature::kReadonlyAndReadwriteStorageTextures)) {
AddError(source) << "read-write storage textures require the "
"readonly_and_readwrite_storage_textures language feature, "
"which is not allowed in the current environment";
return false;
}
break;
case core::Access::kWrite:
break;
case core::Access::kUndefined:
AddError(source) << "storage texture missing access control";
return false;
}
if (DAWN_UNLIKELY(t->TexelFormat() == core::TexelFormat::kR8Unorm &&
!enabled_extensions_.Contains(wgsl::Extension::kChromiumInternalGraphite))) {
AddError(source) << style::Enum(core::TexelFormat::kR8Unorm) << " requires the "
<< style::Code(wgsl::Extension::kChromiumInternalGraphite) << " extension";
return false;
}
if (!IsValidStorageTextureDimension(t->Dim())) {
AddError(source) << "cube dimensions for storage textures are not supported";
return false;
}
if (!IsValidStorageTextureTexelFormat(t->TexelFormat())) {
AddError(source) << "image format must be one of the texel formats specified for storage "
"textures in https://gpuweb.github.io/gpuweb/wgsl/#texel-formats";
return false;
}
return true;
}
bool Validator::SampledTexture(const core::type::SampledTexture* t, const Source& source) const {
if (!t->Type()->UnwrapRef()->IsAnyOf<core::type::F32, core::type::I32, core::type::U32>()) {
AddError(source) << "texture_2d<type>: type must be f32, i32 or u32";
return false;
}
return true;
}
bool Validator::MultisampledTexture(const core::type::MultisampledTexture* t,
const Source& source) const {
if (t->Dim() != core::type::TextureDimension::k2d) {
AddError(source) << "only 2d multisampled textures are supported";
return false;
}
if (!t->Type()->UnwrapRef()->IsAnyOf<core::type::F32, core::type::I32, core::type::U32>()) {
AddError(source) << "texture_multisampled_2d<type>: type must be f32, i32 or u32";
return false;
}
return true;
}
bool Validator::InputAttachment(const core::type::InputAttachment* t, const Source& source) const {
if (!enabled_extensions_.Contains(wgsl::Extension::kChromiumInternalInputAttachments)) {
AddError(source) << "use of " << style::Type("input_attachment")
<< " requires enabling extension "
<< style::Code("chromium_internal_input_attachments");
return false;
}
if (!t->Type()->UnwrapRef()->IsAnyOf<core::type::F32, core::type::I32, core::type::U32>()) {
AddError(source) << "input_attachment<type>: type must be f32, i32 or u32";
return false;
}
return true;
}
bool Validator::InputAttachmentIndexAttribute(const ast::InputAttachmentIndexAttribute* attr,
const core::type::Type* type,
const Source& source) const {
if (!enabled_extensions_.Contains(wgsl::Extension::kChromiumInternalInputAttachments)) {
AddError(source) << "use of " << style::Attribute("@input_attachment_index")
<< " requires enabling extension "
<< style::Code("chromium_internal_input_attachments");
return false;
}
if (!type->Is<core::type::InputAttachment>()) {
std::string invalid_type = sem_.TypeNameOf(type);
AddError(source) << "cannot apply " << style::Attribute("@input_attachment_index")
<< " to declaration of type " << style::Type(invalid_type);
AddNote(attr->source) << style::Attribute("@input_attachment_index")
<< " must only be applied to declarations of "
<< style::Type("input_attachment") << " type";
return false;
}
return true;
}
bool Validator::Materialize(const core::type::Type* to,
const core::type::Type* from,
const Source& source) const {
if (core::type::Type::ConversionRank(from, to) == core::type::Type::kNoConversion) {
AddError(source) << "cannot convert value of type " << style::Type(sem_.TypeNameOf(from))
<< " to type " << style::Type(sem_.TypeNameOf(to));
return false;
}
return true;
}
bool Validator::VariableInitializer(const ast::Variable* v,
const core::type::Type* storage_ty,
const sem::ValueExpression* initializer) const {
auto* initializer_ty = initializer->Type();
auto* value_type = initializer_ty->UnwrapRef(); // Implicit load of RHS
// Value type has to match storage type
if (storage_ty != value_type) {
AddError(v->source) << "cannot initialize " << style::Keyword(v->Kind()) << " of type "
<< style::Type(sem_.TypeNameOf(storage_ty)) << " with value of type "
<< style::Type(sem_.TypeNameOf(initializer_ty));
return false;
}
return true;
}
bool Validator::AddressSpaceLayout(const core::type::Type* store_ty,
core::AddressSpace address_space,
Source source) const {
// https://gpuweb.github.io/gpuweb/wgsl/#storage-class-layout-constraints
auto is_uniform_struct_or_array = [address_space](const core::type::Type* ty) {
return address_space == core::AddressSpace::kUniform &&
ty->IsAnyOf<sem::Array, core::type::Struct>();
};
auto is_uniform_struct = [address_space](const core::type::Type* ty) {
return address_space == core::AddressSpace::kUniform && ty->Is<core::type::Struct>();
};
auto required_alignment_of = [&](const core::type::Type* ty) {
uint32_t actual_align = ty->Align();
uint32_t required_align = actual_align;
if (is_uniform_struct_or_array(ty)) {
required_align = tint::RoundUp(16u, actual_align);
}
return required_align;
};
auto member_name_of = [](const core::type::StructMember* sm) { return sm->Name().Name(); };
// Only validate the [type + address space] once
if (!valid_type_storage_layouts_.Add(TypeAndAddressSpace{store_ty, address_space})) {
return true;
}
if (!core::IsHostShareable(address_space)) {
return true;
}
auto note_usage = [&] {
AddNote(source) << style::Type(store_ty->FriendlyName()) << " used in address space "
<< style::Enum(address_space) << " here";
};
// Among three host-shareable address spaces, f16 is supported in "uniform" and
// "storage" address space, but not "push_constant" address space yet.
if (Is<core::type::F16>(store_ty->DeepestElement()) &&
address_space == core::AddressSpace::kPushConstant) {
AddError(source) << "using " << style::Type("f16") << " in " << style::Enum("push_constant")
<< " address space is not implemented yet";
return false;
}
if (auto* str = store_ty->As<sem::Struct>()) {
auto& str_source = str->Declaration()->name->source;
for (size_t i = 0; i < str->Members().Length(); ++i) {
auto* const m = str->Members()[i];
uint32_t required_align = required_alignment_of(m->Type());
// Recurse into the member type.
if (!AddressSpaceLayout(m->Type(), address_space, m->Declaration()->type->source)) {
AddNote(str_source) << "see layout of struct:\n" << str->Layout();
note_usage();
return false;
}
// Validate that member is at a valid byte offset
if (m->Offset() % required_align != 0 &&
!enabled_extensions_.Contains(
wgsl::Extension::kChromiumInternalRelaxedUniformLayout)) {
AddError(m->Declaration()->source)
<< "the offset of a struct member of type "
<< style::Type(m->Type()->UnwrapRef()->FriendlyName()) << " in address space "
<< style::Enum(address_space) << " must be a multiple of " << required_align
<< " bytes, but " << style::Variable(member_name_of(m))
<< " is currently at offset " << m->Offset() << ". Consider setting "
<< style::Attribute("@align") << style::Code("(", required_align, ")")
<< " on this member";
AddNote(str_source) << "see layout of struct:\n" << str->Layout();
if (auto* member_str = m->Type()->As<sem::Struct>()) {
AddNote(member_str->Declaration()->name->source)
<< "and layout of struct member:\n"
<< member_str->Layout();
}
note_usage();
return false;
}
// For uniform buffers, validate that the number of bytes between the previous member of
// type struct and the current is a multiple of 16 bytes.
auto* const prev_member = (i == 0) ? nullptr : str->Members()[i - 1];
if (prev_member && is_uniform_struct(prev_member->Type())) {
const uint32_t prev_to_curr_offset = m->Offset() - prev_member->Offset();
if (prev_to_curr_offset % 16 != 0 &&
!enabled_extensions_.Contains(
wgsl::Extension::kChromiumInternalRelaxedUniformLayout)) {
AddError(m->Declaration()->source)
<< style::Enum("uniform")
<< " storage requires that the number of bytes between the start of the "
"previous member of type struct and the current member be a "
"multiple of 16 bytes, but there are currently "
<< prev_to_curr_offset << " bytes between "
<< style::Variable(member_name_of(prev_member)) << " and "
<< style::Variable(member_name_of(m)) << ". Consider setting "
<< style::Attribute("@align") << style::Code("(16)") << " on this member";
AddNote(str_source) << "see layout of struct:\n" << str->Layout();
auto* prev_member_str = prev_member->Type()->As<sem::Struct>();
AddNote(prev_member_str->Declaration()->name->source)
<< "and layout of previous member struct:\n"
<< prev_member_str->Layout();
note_usage();
return false;
}
}
}
}
// For uniform buffer array members, validate that array elements are aligned to 16 bytes
if (auto* arr = store_ty->As<sem::Array>()) {
// Recurse into the element type.
// TODO(crbug.com/tint/1388): Ideally we'd pass the source for nested element type here, but
// we can't easily get that from the semantic node. We should consider recursing through the
// AST type nodes instead.
if (!AddressSpaceLayout(arr->ElemType(), address_space, source)) {
return false;
}
if (address_space == core::AddressSpace::kUniform &&
!enabled_extensions_.Contains(wgsl::Extension::kChromiumInternalRelaxedUniformLayout)) {
// We already validated that this array member is itself aligned to 16 bytes above, so
// we only need to validate that stride is a multiple of 16 bytes.
if (arr->Stride() % 16 != 0) {
// Since WGSL has no stride attribute, try to provide a useful hint for how the
// shader author can resolve the issue.
StyledText hint;
if (arr->ElemType()->Is<core::type::Scalar>()) {
hint << "Consider using a vector or struct as the element type instead.";
} else if (auto* vec = arr->ElemType()->As<core::type::Vector>();
vec && vec->Type()->Size() == 4) {
hint << "Consider using a vec4 instead.";
} else if (arr->ElemType()->Is<sem::Struct>()) {
hint << "Consider using the " << style::Attribute("@size")
<< " attribute on the last struct member.";
} else {
hint << "Consider wrapping the element type in a struct and using the "
<< style::Attribute("@size") << " attribute.";
}
AddError(source) << style::Enum("uniform")
<< " storage requires that array elements are aligned to 16 "
"bytes, but array element of type "
<< style::Type(arr->ElemType()->FriendlyName())
<< " has a stride of " << arr->Stride() << " bytes. " << hint;
return false;
}
}
}
return true;
}
bool Validator::LocalVariable(const sem::Variable* local) const {
auto* decl = local->Declaration();
if (IsArrayWithOverrideCount(local->Type())) {
RaiseArrayWithOverrideCountError(decl->type ? decl->type->source
: decl->initializer->source);
return false;
}
return Switch(
decl, //
[&](const ast::Var* var) {
if (IsValidationEnabled(var->attributes,
ast::DisabledValidation::kIgnoreAddressSpace)) {
if (!local->Type()->UnwrapRef()->IsConstructible()) {
AddError(var->type ? var->type->source : var->source)
<< "function-scope " << style::Keyword("var")
<< " must have a constructible type";
return false;
}
}
return Var(local);
}, //
[&](const ast::Let*) { return Let(local); }, //
[&](const ast::Const*) { return true; }, //
TINT_ICE_ON_NO_MATCH);
}
bool Validator::GlobalVariable(
const sem::GlobalVariable* global,
const Hashmap<OverrideId, const sem::Variable*, 8>& override_ids) const {
auto* decl = global->Declaration();
if (global->AddressSpace() != core::AddressSpace::kWorkgroup &&
IsArrayWithOverrideCount(global->Type())) {
RaiseArrayWithOverrideCountError(decl->type ? decl->type->source
: decl->initializer->source);
return false;
}
bool ok = Switch(
decl, //
[&](const ast::Var* var) {
if (auto* init = global->Initializer();
init && init->Stage() > core::EvaluationStage::kOverride) {
AddError(init->Declaration()->source)
<< "module-scope " << style::Keyword("var")
<< " initializer must be a constant or override-expression";
return false;
}
if (!var->declared_address_space && !global->Type()->UnwrapRef()->IsHandle()) {
AddError(decl->source) << "module-scope " << style::Keyword("var")
<< " declarations that are not of texture or sampler types "
"must provide an address space";
return false;
}
return Var(global);
},
[&](const ast::Override*) { return Override(global, override_ids); },
[&](const ast::Const*) { return Const(global); }, //
TINT_ICE_ON_NO_MATCH);
if (!ok) {
return false;
}
if (global->AddressSpace() == core::AddressSpace::kFunction) {
AddError(decl->source) << "module-scope " << style::Keyword("var")
<< " must not use address space " << style::Enum("function");
return false;
}
auto* input_attachment_index_attr =
ast::GetAttribute<ast::InputAttachmentIndexAttribute>(decl->attributes);
if (input_attachment_index_attr &&
!InputAttachmentIndexAttribute(input_attachment_index_attr, global->Type()->UnwrapRef(),
decl->source)) {
return false;
}
switch (global->AddressSpace()) {
case core::AddressSpace::kUniform:
case core::AddressSpace::kStorage:
case core::AddressSpace::kHandle: {
// https://gpuweb.github.io/gpuweb/wgsl/#resource-interface
// Each resource variable must be declared with both group and binding attributes.
if (!decl->HasBindingPoint()) {
AddError(decl->source)
<< "resource variables require " << style::Attribute("@group") << " and "
<< style::Attribute("@binding") << " attributes";
return false;
}
if (global->Type()->UnwrapRef()->Is<core::type::InputAttachment>() &&
!input_attachment_index_attr) {
AddError(decl->source)
<< style::Type("input_attachment") << " variables require "
<< style::Attribute("@input_attachment_index") << " attribute";
return false;
}
break;
}
default: {
auto* binding_attr = ast::GetAttribute<ast::BindingAttribute>(decl->attributes);
auto* group_attr = ast::GetAttribute<ast::GroupAttribute>(decl->attributes);
if (binding_attr || group_attr) {
// https://gpuweb.github.io/gpuweb/wgsl/#attribute-binding
// Must only be applied to a resource variable
AddError(decl->source)
<< "non-resource variables must not have " << style::Attribute("@group")
<< " or " << style::Attribute("@binding") << " attributes";
return false;
}
}
}
return true;
}
bool Validator::Var(const sem::Variable* v) const {
auto* var = v->Declaration()->As<ast::Var>();
auto* store_ty = v->Type()->UnwrapRef();
if (!IsStorable(store_ty)) {
AddError(var->source) << sem_.TypeNameOf(store_ty)
<< " cannot be used as the type of a var";
return false;
}
if (store_ty->IsHandle() && var->declared_address_space) {
// https://gpuweb.github.io/gpuweb/wgsl/#module-scope-variables
// If the store type is a texture type or a sampler type, then the variable declaration must
// not have a address space attribute. The address space will always be handle.
AddError(var->source) << "variables of type " << style::Type(sem_.TypeNameOf(store_ty))
<< " must not specify an address space";
return false;
}
if (var->declared_access) {
// https://www.w3.org/TR/WGSL/#access-mode-defaults
// When writing a variable declaration or a pointer type in WGSL source:
// * For the storage address space, the access mode is optional, and defaults to read.
// * For other address spaces, the access mode must not be written.
if (v->AddressSpace() != core::AddressSpace::kStorage) {
AddError(var->source)
<< "only variables in <storage> address space may specify an access mode";
return false;
}
}
if (var->initializer) {
switch (v->AddressSpace()) {
case core::AddressSpace::kPrivate:
case core::AddressSpace::kFunction:
break; // Allowed an initializer
default:
// https://gpuweb.github.io/gpuweb/wgsl/#var-and-let
// Optionally has an initializer expression, if the variable is in the private or
// function address spaces.
AddError(var->source)
<< "var of address space " << style::Enum(v->AddressSpace())
<< " cannot have an initializer. var initializers are only supported for the "
"address spaces "
<< style::Enum("private") << " and " << style::Enum("function");
return false;
}
}
if (!CheckTypeAccessAddressSpace(v->Type()->UnwrapRef(), v->Access(), v->AddressSpace(),
var->attributes, var->source)) {
return false;
}
if (IsValidationEnabled(var->attributes, ast::DisabledValidation::kIgnoreAddressSpace) &&
(v->AddressSpace() == core::AddressSpace::kIn ||
v->AddressSpace() == core::AddressSpace::kOut)) {
AddError(var->source) << "invalid use of input/output address space";
return false;
}
return true;
}
bool Validator::Let(const sem::Variable* v) const {
auto* decl = v->Declaration();
auto* storage_ty = v->Type()->UnwrapRef();
if (!(storage_ty->IsConstructible() || storage_ty->Is<core::type::Pointer>())) {
AddError(decl->source) << sem_.TypeNameOf(storage_ty) << " cannot be used as the type of a "
<< style::Keyword("let");
return false;
}
return true;
}
bool Validator::Override(const sem::GlobalVariable* v,
const Hashmap<OverrideId, const sem::Variable*, 8>& override_ids) const {
auto* decl = v->Declaration();
auto* storage_ty = v->Type()->UnwrapRef();
if (auto* init = v->Initializer(); init && init->Stage() > core::EvaluationStage::kOverride) {
AddError(init->Declaration()->source)
<< style::Keyword("override") << " initializer must be an override-expression";
return false;
}
if (auto id = v->Attributes().override_id) {
if (auto var = override_ids.Get(*id); var && *var != v) {
auto* attr = ast::GetAttribute<ast::IdAttribute>(v->Declaration()->attributes);
AddError(attr->source) << style::Attribute("@id") << " values must be unique";
AddNote(ast::GetAttribute<ast::IdAttribute>((*var)->Declaration()->attributes)->source)
<< "a override with an ID of " << id->value << " was previously declared here";
return false;
}
}
if (!storage_ty->Is<core::type::Scalar>()) {
AddError(decl->source) << sem_.TypeNameOf(storage_ty) << " cannot be used as the type of a "
<< style::Keyword("override");
return false;
}
return true;
}
bool Validator::Const(const sem::Variable*) const {
return true;
}
bool Validator::Parameter(const sem::Variable* var) const {
auto* decl = var->Declaration();
if (IsValidationDisabled(decl->attributes, ast::DisabledValidation::kFunctionParameter)) {
return true;
}
if (auto* ref = var->Type()->As<core::type::Pointer>()) {
if (IsValidationEnabled(decl->attributes, ast::DisabledValidation::kIgnoreAddressSpace)) {
bool ok = false;
auto sc = ref->AddressSpace();
switch (sc) {
case core::AddressSpace::kFunction:
case core::AddressSpace::kPrivate:
ok = true;
break;
case core::AddressSpace::kStorage:
case core::AddressSpace::kUniform:
case core::AddressSpace::kWorkgroup:
ok = allowed_features_.features.count(
wgsl::LanguageFeature::kUnrestrictedPointerParameters) != 0;
break;
default:
break;
}
if (!ok) {
AddError(decl->source) << "function parameter of pointer type cannot be in "
<< style::Enum(sc) << " address space";
return false;
}
}
}
if (IsPlain(var->Type())) {
if (!var->Type()->IsConstructible()) {
AddError(decl->type->source) << "type of function parameter must be constructible";
return false;
}
} else if (!var->Type()
->IsAnyOf<core::type::Texture, core::type::Sampler, core::type::Pointer>()) {
AddError(decl->source) << "type of function parameter cannot be "
<< sem_.TypeNameOf(var->Type());
return false;
}
return true;
}
bool Validator::BuiltinAttribute(const ast::BuiltinAttribute* attr,
const core::type::Type* storage_ty,
ast::PipelineStage stage,
const bool is_input,
const bool ignore_clip_distances_type_validation) const {
auto* type = storage_ty->UnwrapRef();
bool is_stage_mismatch = false;
bool is_output = !is_input;
auto builtin = attr->builtin;
auto err_builtin_type = [&](std::string_view required) {
AddError(attr->source) << "store type of " << style::Attribute("@builtin")
<< style::Code("(", style::Enum(builtin), ")") << " must be "
<< style::Type(required);
};
switch (builtin) {
case core::BuiltinValue::kPosition: {
if (stage != ast::PipelineStage::kNone &&
!((is_input && stage == ast::PipelineStage::kFragment) ||
(is_output && stage == ast::PipelineStage::kVertex))) {
is_stage_mismatch = true;
}
auto* vec = type->As<core::type::Vector>();
if (!(vec && vec->Width() == 4 && vec->Type()->Is<core::type::F32>())) {
err_builtin_type("vec4<f32>");
return false;
}
break;
}
case core::BuiltinValue::kGlobalInvocationId:
case core::BuiltinValue::kLocalInvocationId:
case core::BuiltinValue::kNumWorkgroups:
case core::BuiltinValue::kWorkgroupId:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kCompute && is_input)) {
is_stage_mismatch = true;
}
if (!(type->IsUnsignedIntegerVector() &&
type->As<core::type::Vector>()->Width() == 3)) {
err_builtin_type("vec3<u32>");
return false;
}
break;
case core::BuiltinValue::kFragDepth:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kFragment && !is_input)) {
is_stage_mismatch = true;
}
if (!type->Is<core::type::F32>()) {
err_builtin_type("f32");
return false;
}
break;
case core::BuiltinValue::kFrontFacing:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kFragment && is_input)) {
is_stage_mismatch = true;
}
if (!type->Is<core::type::Bool>()) {
err_builtin_type("bool");
return false;
}
break;
case core::BuiltinValue::kLocalInvocationIndex:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kCompute && is_input)) {
is_stage_mismatch = true;
}
if (!type->Is<core::type::U32>()) {
err_builtin_type("u32");
return false;
}
break;
case core::BuiltinValue::kVertexIndex:
case core::BuiltinValue::kInstanceIndex:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kVertex && is_input)) {
is_stage_mismatch = true;
}
if (!type->Is<core::type::U32>()) {
err_builtin_type("u32");
return false;
}
break;
case core::BuiltinValue::kSampleMask:
if (stage != ast::PipelineStage::kNone && !(stage == ast::PipelineStage::kFragment)) {
is_stage_mismatch = true;
}
if (!type->Is<core::type::U32>()) {
err_builtin_type("u32");
return false;
}
break;
case core::BuiltinValue::kSampleIndex:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kFragment && is_input)) {
is_stage_mismatch = true;
}
if (!type->Is<core::type::U32>()) {
err_builtin_type("u32");
return false;
}
break;
case core::BuiltinValue::kSubgroupInvocationId:
case core::BuiltinValue::kSubgroupSize:
if (!(enabled_extensions_.Contains(wgsl::Extension::kChromiumExperimentalSubgroups) ||
enabled_extensions_.Contains(wgsl::Extension::kSubgroups))) {
AddError(attr->source)
<< "use of " << style::Attribute("@builtin")
<< style::Code("(", style::Enum(builtin), ")")
<< " attribute requires enabling extension " << style::Code("subgroups");
return false;
}
if (!type->Is<core::type::U32>()) {
err_builtin_type("u32");
return false;
}
if (stage != ast::PipelineStage::kNone && !((stage == ast::PipelineStage::kCompute ||
stage == ast::PipelineStage::kFragment) &&
is_input)) {
AddError(attr->source)
<< style::Attribute("@builtin") << style::Code("(", style::Enum(builtin), ")")
<< " is only valid as a compute or fragment shader input";
return false;
}
break;
case core::BuiltinValue::kClipDistances: {
if (!enabled_extensions_.Contains(wgsl::Extension::kClipDistances)) {
AddError(attr->source)
<< "use of " << style::Attribute("@builtin")
<< style::Code("(", style::Enum(builtin), ")")
<< " requires enabling extension " << style::Code("clip_distances");
return false;
}
auto* arr = type->As<sem::Array>();
if (!ignore_clip_distances_type_validation &&
!(arr && arr->ElemType()->Is<core::type::F32>() &&
arr->ConstantCount().has_value() &&
*arr->ConstantCount() <= kMaxClipDistancesSize)) {
AddError(attr->source)
<< "store type of " << style::Attribute("@builtin")
<< style::Code("(", style::Enum(builtin), ")") << " must be "
<< style::Type("array<f32, N>") << " (N <= " << kMaxClipDistancesSize << ")";
return false;
}
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kVertex && !is_input)) {
is_stage_mismatch = true;
}
break;
}
default:
break;
}
if (is_stage_mismatch) {
AddError(attr->source) << style::Attribute("@builtin")
<< style::Code("(", style::Enum(builtin), ")")
<< " cannot be used for " << stage << " shader "
<< (is_input ? "input" : "output");
return false;
}
return true;
}
bool Validator::InterpolateAttribute(const ast::InterpolateAttribute* attr,
const core::type::Type* storage_ty,
const ast::PipelineStage stage) const {
if (stage == ast::PipelineStage::kCompute) {
AddError(attr->source) << style::Attribute("@", attr->Name())
<< " cannot be used by compute shaders";
return false;
}
auto* type = storage_ty->UnwrapRef();
auto i_type = attr->interpolation.type;
auto i_sampling = attr->interpolation.sampling;
if (DAWN_UNLIKELY(i_type == core::InterpolationType::kUndefined)) {
return false;
}
if (type->IsIntegerScalarOrVector() && i_type != core::InterpolationType::kFlat) {
AddError(attr->source) << "interpolation type must be " << style::Enum("flat")
<< " for integral user-defined IO types";
return false;
}
if (i_sampling != core::InterpolationSampling::kUndefined) {
bool is_first_or_either = i_sampling == core::InterpolationSampling::kFirst ||
i_sampling == core::InterpolationSampling::kEither;
if (i_type == core::InterpolationType::kFlat) {
if (!is_first_or_either) {
AddError(attr->source)
<< "flat interpolation can only use 'first' and 'either' sampling parameters";
return false;
}
if (mode_ == wgsl::ValidationMode::kCompat &&
i_sampling == core::InterpolationSampling::kFirst) {
AddError(attr->source) << "flat interpolation must use 'either' sampling parameter "
"in compatibility mode";
return false;
}
} else {
if (is_first_or_either) {
AddError(attr->source) << "'first' and 'either' sampling parameters can only be "
"used with flat interpolation";
return false;
}
if (mode_ == wgsl::ValidationMode::kCompat &&
i_sampling == core::InterpolationSampling::kSample) {
AddError(attr->source)
<< "use of '@interpolate(..., sample)' is not allowed in compatibility mode";
return false;
}
}
} else {
if (mode_ == wgsl::ValidationMode::kCompat && i_type == core::InterpolationType::kFlat) {
AddError(attr->source)
<< "flat interpolation must use 'either' sampling parameter in compatibility mode";
return false;
}
}
if (mode_ == wgsl::ValidationMode::kCompat && i_type == core::InterpolationType::kLinear) {
AddError(attr->source)
<< "use of '@interpolate(linear)' is not allowed in compatibility mode";
return false;
}
return true;
}
bool Validator::InvariantAttribute(const ast::InvariantAttribute* attr,
const ast::PipelineStage stage) const {
if (stage == ast::PipelineStage::kCompute) {
AddError(attr->source) << style::Attribute("@", attr->Name())
<< " cannot be used by compute shaders";
return false;
}
return true;
}
bool Validator::Function(const sem::Function* func, ast::PipelineStage stage) const {
auto* decl = func->Declaration();
for (auto* attr : decl->attributes) {
bool ok = Switch(
attr, //
[&](const ast::WorkgroupAttribute*) {
if (decl->PipelineStage() != ast::PipelineStage::kCompute) {
AddError(attr->source) << style::Attribute("@workgroup_size")
<< " is only valid for compute stages";
return false;
}
return true;
},
[&](const ast::MustUseAttribute*) {
if (func->ReturnType()->Is<core::type::Void>()) {
AddError(attr->source)
<< style::Attribute("@must_use")
<< " can only be applied to functions that return a value";
return false;
}
return true;
},
[&](Default) { return true; });
if (!ok) {
return false;
}
}
if (decl->params.Length() > kMaxFunctionParameters) {
AddError(decl->name->source) << "function declares " << decl->params.Length()
<< " parameters, maximum is " << kMaxFunctionParameters;
return false;
}
if (!func->ReturnType()->Is<core::type::Void>()) {
if (!func->ReturnType()->IsConstructible()) {
AddError(decl->return_type->source)
<< "function return type must be a constructible type";
return false;
}
if (decl->body) {
sem::Behaviors behaviors{sem::Behavior::kNext};
if (auto* last = decl->body->Last()) {
behaviors = sem_.Get(last)->Behaviors();
}
if (behaviors.Contains(sem::Behavior::kNext)) {
auto end_source = decl->body->source.End();
end_source.range.begin.column--;
AddError(end_source) << "missing return at end of function";
return false;
}
} else if (DAWN_UNLIKELY(IsValidationEnabled(
decl->attributes, ast::DisabledValidation::kFunctionHasNoBody))) {
TINT_ICE() << "function " << decl->name->symbol.NameView() << " has no body";
}
}
if (decl->IsEntryPoint()) {
if (!EntryPoint(func, stage)) {
return false;
}
}
// https://www.w3.org/TR/WGSL/#behaviors-rules
// a function behavior is always one of {}, or {Next}.
if (DAWN_UNLIKELY(func->Behaviors() != sem::Behaviors{} &&
func->Behaviors() != sem::Behavior::kNext)) {
auto name = decl->name->symbol.NameView();
TINT_ICE() << "function '" << name << "' behaviors are: " << func->Behaviors();
}
return true;
}
bool Validator::EntryPoint(const sem::Function* func, ast::PipelineStage stage) const {
auto* decl = func->Declaration();
// Use a lambda to validate the entry point attributes for a type.
// Persistent state is used to track which builtins and locations have already been seen, in
// order to catch conflicts.
// TODO(jrprice): This state could be stored in sem::Function instead, and then passed to
// sem::Function since it would be useful there too.
Hashset<core::BuiltinValue, 4> builtins;
Hashset<std::pair<uint32_t, uint32_t>, 8> locations_and_blend_srcs;
Hashset<uint32_t, 4> colors;
enum class ParamOrRetType {
kParameter,
kReturnType,
};
// Inner lambda that is applied to a type and all of its members.
auto validate_entry_point_attributes_inner = [&](VectorRef<const ast::Attribute*> attrs,
const core::type::Type* ty, Source source,
ParamOrRetType param_or_ret,
bool is_struct_member,
std::optional<uint32_t> location,
std::optional<uint32_t> blend_src,
std::optional<uint32_t> color) {
// Scan attributes for pipeline IO attributes.
// Check for overlap with attributes that have been seen previously.
const ast::Attribute* pipeline_io_attribute = nullptr;
const ast::LocationAttribute* location_attribute = nullptr;
const ast::ColorAttribute* color_attribute = nullptr;
const ast::BlendSrcAttribute* blend_src_attribute = nullptr;
const ast::InterpolateAttribute* interpolate_attribute = nullptr;
const ast::InvariantAttribute* invariant_attribute = nullptr;
bool ignore_clip_distances_type =
IsValidationDisabled(attrs, ast::DisabledValidation::kIgnoreClipDistancesType);
for (auto* attr : attrs) {
bool ok = Switch(
attr, //
[&](const ast::BuiltinAttribute* builtin_attr) {
auto builtin = builtin_attr->builtin;
if (pipeline_io_attribute) {
AddError(attr->source) << "multiple entry point IO attributes";
AddNote(pipeline_io_attribute->source)
<< "previously consumed "
<< style::Attribute("@", pipeline_io_attribute->Name());
return false;
}
pipeline_io_attribute = attr;
if (builtins.Contains(builtin)) {
AddError(decl->source)
<< style::Attribute("@builtin")
<< style::Code("(", style::Enum(builtin), ")")
<< " appears multiple times as pipeline "
<< (param_or_ret == ParamOrRetType::kParameter ? "input" : "output");
return false;
}
if (!BuiltinAttribute(builtin_attr, ty, stage,
/* is_input */ param_or_ret == ParamOrRetType::kParameter,
ignore_clip_distances_type)) {
return false;
}
builtins.Add(builtin);
return true;
},
[&](const ast::LocationAttribute* loc_attr) {
location_attribute = loc_attr;
if (pipeline_io_attribute) {
AddError(attr->source) << "multiple entry point IO attributes";
AddNote(pipeline_io_attribute->source)
<< "previously consumed "
<< style::Attribute("@", pipeline_io_attribute->Name());
return false;
}
pipeline_io_attribute = attr;
if (DAWN_UNLIKELY(!location.has_value())) {
TINT_ICE() << "@location has no value";
}
return LocationAttribute(loc_attr, ty, stage, source);
},
[&](const ast::BlendSrcAttribute* blend_src_attr) {
blend_src_attribute = blend_src_attr;
if (DAWN_UNLIKELY(!blend_src.has_value())) {
TINT_ICE() << "@blend_src has no value";
}
bool is_input = param_or_ret == ParamOrRetType::kParameter;
return BlendSrcAttribute(blend_src_attr, stage, is_input);
},
[&](const ast::ColorAttribute* col_attr) {
color_attribute = col_attr;
if (pipeline_io_attribute) {
AddError(attr->source) << "multiple entry point IO attributes";
AddNote(pipeline_io_attribute->source)
<< "previously consumed "
<< style::Attribute("@", pipeline_io_attribute->Name());
return false;
}
pipeline_io_attribute = attr;
bool is_input = param_or_ret == ParamOrRetType::kParameter;
if (DAWN_UNLIKELY(!color.has_value())) {
TINT_ICE() << "@color has no value";
}
return ColorAttribute(col_attr, ty, stage, source, is_input);
},
[&](const ast::InterpolateAttribute* interpolate) {
interpolate_attribute = interpolate;
return InterpolateAttribute(interpolate, ty, stage);
},
[&](const ast::InvariantAttribute* invariant) {
invariant_attribute = invariant;
return InvariantAttribute(invariant, stage);
},
[&](const ast::InternalAttribute* internal) {
pipeline_io_attribute = internal;
return true;
},
[&](Default) { return true; });
if (!ok) {
return false;
}
}
if (IsValidationEnabled(attrs, ast::DisabledValidation::kEntryPointParameter)) {
if (is_struct_member && ty->Is<core::type::Struct>()) {
AddError(source) << "nested structures cannot be used for entry point IO";
return false;
}
if (!ty->Is<core::type::Struct>() && !pipeline_io_attribute) {
auto& err = AddError(source) << "missing entry point IO attribute";
if (!is_struct_member) {
err << (param_or_ret == ParamOrRetType::kParameter ? " on parameter"
: " on return type");
}
return false;
}
if (pipeline_io_attribute && pipeline_io_attribute->Is<ast::LocationAttribute>()) {
if (ty->IsIntegerScalarOrVector() && !interpolate_attribute) {
if (decl->PipelineStage() == ast::PipelineStage::kVertex &&
param_or_ret == ParamOrRetType::kReturnType) {
AddError(source)
<< "integral user-defined vertex outputs must have a "
<< style::Attribute("@interpolate")
<< style::Code("(", style::Enum("flat"), ")") << " attribute";
return false;
}
if (decl->PipelineStage() == ast::PipelineStage::kFragment &&
param_or_ret == ParamOrRetType::kParameter) {
AddError(source)
<< "integral user-defined fragment inputs must have a "
<< style::Attribute("@interpolate")
<< style::Code("(", style::Enum("flat"), ")") << " attribute";
return false;
}
}
}
if (location_attribute) {
std::pair<uint32_t, uint32_t> location_and_blend_src(location.value(),
blend_src.value_or(0));
if (!locations_and_blend_srcs.Add(location_and_blend_src)) {
auto& err = AddError(location_attribute->source)
<< style::Attribute("@location")
<< style::Code("(", style::Literal(location.value()), ")");
if (blend_src_attribute) {
err << style::Attribute(" @blend_src")
<< style::Code("(", style::Literal(blend_src.value()), ")");
}
err << " appears multiple times";
return false;
}
}
if (color_attribute && !colors.Add(color.value())) {
AddError(color_attribute->source)
<< style::Attribute("@color")
<< style::Code("(", style::Literal(color.value()), ")")
<< " appears multiple times";
return false;
}
if (interpolate_attribute) {
if (!pipeline_io_attribute ||
!pipeline_io_attribute->Is<ast::LocationAttribute>()) {
AddError(interpolate_attribute->source)
<< style::Attribute("@interpolate") << " can only be used with "
<< style::Attribute("@location");
return false;
}
}
if (invariant_attribute) {
bool has_position = false;
if (pipeline_io_attribute) {
if (auto* builtin_attr = pipeline_io_attribute->As<ast::BuiltinAttribute>()) {
has_position = (builtin_attr->builtin == core::BuiltinValue::kPosition);
}
}
if (!has_position) {
AddError(invariant_attribute->source)
<< style::Attribute("@invariant") << " must be applied to a "
<< style::Attribute("@builtin")
<< style::Code("(", style::Enum("position"), ")");
return false;
}
}
}
return true;
};
// Outer lambda for validating the entry point attributes for a type.
auto validate_entry_point_attributes =
[&](VectorRef<const ast::Attribute*> attrs, const core::type::Type* ty, Source source,
ParamOrRetType param_or_ret, std::optional<uint32_t> location,
std::optional<uint32_t> blend_src, std::optional<uint32_t> color) {
if (!validate_entry_point_attributes_inner(attrs, ty, source, param_or_ret,
/*is_struct_member*/ false, location,
blend_src, color)) {
return false;
}
if (auto* str = ty->As<sem::Struct>()) {
for (auto* member : str->Members()) {
if (!validate_entry_point_attributes_inner(
member->Declaration()->attributes, member->Type(),
member->Declaration()->source, param_or_ret,
/*is_struct_member*/ true, member->Attributes().location,
member->Attributes().blend_src, member->Attributes().color)) {
AddNote(decl->source) << "while analyzing entry point "
<< style::Function(decl->name->symbol.NameView());
return false;
}
}
}
return true;
};
for (auto* param : func->Parameters()) {
auto* param_decl = param->Declaration();
auto& attrs = param->Attributes();
if (!validate_entry_point_attributes(param_decl->attributes, param->Type(),
param_decl->source, ParamOrRetType::kParameter,
attrs.location, attrs.blend_src, attrs.color)) {
return false;
}
}
// Clear IO sets after parameter validation. Builtin and location attributes in return types
// should be validated independently from those used in parameters.
builtins.Clear();
locations_and_blend_srcs.Clear();
if (!func->ReturnType()->Is<core::type::Void>()) {
if (!validate_entry_point_attributes(decl->return_type_attributes, func->ReturnType(),
decl->source, ParamOrRetType::kReturnType,
func->ReturnLocation(), func->ReturnIndex(),
/* color */ std::nullopt)) {
return false;
}
}
if (decl->PipelineStage() == ast::PipelineStage::kVertex &&
!builtins.Contains(core::BuiltinValue::kPosition)) {
// Check module-scope variables, as the SPIR-V sanitizer generates these.
bool found = false;
for (auto* global : func->TransitivelyReferencedGlobals()) {
if (auto* builtin_attr =
ast::GetAttribute<ast::BuiltinAttribute>(global->Declaration()->attributes)) {
if (builtin_attr->builtin == core::BuiltinValue::kPosition) {
found = true;
break;
}
}
}
if (!found) {
AddError(decl->source) << "a vertex shader must include the " << style::Enum("position")
<< " builtin in its return type";
return false;
}
}
if (decl->PipelineStage() == ast::PipelineStage::kCompute) {
if (!ast::HasAttribute<ast::WorkgroupAttribute>(decl->attributes)) {
AddError(decl->source) << "a compute shader must include "
<< style::Attribute("@workgroup_size") << " in its attributes";
return false;
}
}
// Validate there are no resource variable binding collisions
Hashmap<BindingPoint, const ast::Variable*, 8> binding_points;
for (auto* global : func->TransitivelyReferencedGlobals()) {
auto* var_decl = global->Declaration()->As<ast::Var>();
if (!var_decl) {
continue;
}
auto bp = global->Attributes().binding_point;
if (!bp) {
continue;
}
if (auto added = binding_points.Add(*bp, var_decl);
!added &&
IsValidationEnabled(decl->attributes,
ast::DisabledValidation::kBindingPointCollision) &&
IsValidationEnabled(added.value->attributes,
ast::DisabledValidation::kBindingPointCollision)) {
// https://gpuweb.github.io/gpuweb/wgsl/#resource-interface
// Bindings must not alias within a shader stage: two different variables in the
// resource interface of a given shader must not have the same group and binding values,
// when considered as a pair of values.
auto func_name = decl->name->symbol.NameView();
AddError(var_decl->source)
<< "entry point " << style::Function(func_name)
<< " references multiple variables that use the same resource binding "
<< style::Attribute("@group") << style::Code("(", style::Literal(bp->group), ")")
<< ", " << style::Attribute("@binding")
<< style::Code("(", style::Literal(bp->binding), ")");
AddNote(added.value->source) << "first resource binding usage declared here";
return false;
}
}
return true;
}
bool Validator::EvaluationStage(const sem::ValueExpression* expr,
core::EvaluationStage latest_stage,
std::string_view constraint) const {
if (expr->Stage() == core::EvaluationStage::kNotEvaluated) {
return true;
}
if (expr->Stage() > latest_stage) {
auto stage_name = [](core::EvaluationStage stage) -> std::string {
switch (stage) {
case core::EvaluationStage::kRuntime:
return "a runtime-expression";
case core::EvaluationStage::kOverride:
return "an override-expression";
case core::EvaluationStage::kConstant:
return "a const-expression";
case core::EvaluationStage::kNotEvaluated:
return "an unevaluated expression";
}
return "<unknown>";
};
AddError(expr->Declaration()->source)
<< constraint << " requires " << stage_name(latest_stage) << ", but expression is "
<< stage_name(expr->Stage());
if (auto* stmt = expr->Stmt()) {
if (auto* decl = As<ast::VariableDeclStatement>(stmt->Declaration())) {
if (decl->variable->Is<ast::Const>()) {
AddNote(decl->source) << "consider changing " << style::Keyword("const")
<< " to " << style::Keyword("let");
}
}
}
return false;
}
return true;
}
bool Validator::Statements(VectorRef<const ast::Statement*> stmts) const {
for (auto* stmt : stmts) {
if (!sem_.Get(stmt)->IsReachable()) {
if (auto* d = MaybeAddDiagnostic(wgsl::ChromiumDiagnosticRule::kUnreachableCode,
stmt->source)) {
*d << "code is unreachable";
if (d->severity >= diag::Severity::Error) {
return false;
}
}
break;
}
}
return true;
}
bool Validator::BinaryExpression(const ast::Node* node,
const core::BinaryOp op,
const tint::sem::ValueExpression* lhs,
const tint::sem::ValueExpression* rhs) const {
switch (op) {
case core::BinaryOp::kShiftLeft:
case core::BinaryOp::kShiftRight: {
// If lhs value is a concrete type, and rhs is a const-expression greater than or equal
// to the bit width of lhs, then it is a shader-creation error.
const auto* elem_type = lhs->Type()->UnwrapRef()->DeepestElement();
if (!elem_type->IsAbstract() && rhs->Stage() == core::EvaluationStage::kConstant) {
const uint32_t bit_width = elem_type->Size() * 8;
auto* rhs_val = rhs->ConstantValue();
for (size_t i = 0, n = rhs_val->NumElements(); i < n; i++) {
auto* shift_val = n == 1 ? rhs_val : rhs_val->Index(i);
if (shift_val->ValueAs<u32>() >= bit_width) {
AddError(node->source)
<< "shift " << (op == core::BinaryOp::kShiftLeft ? "left" : "right")
<< " value must be less than the bit width of the lhs, which is "
<< bit_width;
return false;
}
}
}
return true;
}
case core::BinaryOp::kDivide:
case core::BinaryOp::kModulo: {
// Integer division by zero should be checked for the partial evaluation case (only rhs
// is const). FP division by zero is only invalid when the whole expression is
// constant-evaluated.
if (rhs->Type()->IsIntegerScalarOrVector() &&
rhs->Stage() == core::EvaluationStage::kConstant) {
if (rhs->ConstantValue()->AnyZero()) {
AddError(node->source) << "integer division by zero is invalid";
return false;
}
}
return true;
}
default: {
return true;
}
}
}
bool Validator::BreakStatement(const sem::Statement* stmt,
sem::Statement* current_statement) const {
if (!stmt->FindFirstParent<sem::LoopBlockStatement, sem::CaseStatement>()) {
AddError(stmt->Declaration()->source) << "break statement must be in a loop or switch case";
return false;
}
if (ClosestContinuing(/*stop_at_loop*/ true, /* stop_at_switch */ true, current_statement) !=
nullptr) {
AddError(stmt->Declaration()->source)
<< style::Keyword("break") << " must not be used to exit from a continuing block. Use "
<< style::Keyword("break if") << " instead.";
return false;
}
return true;
}
bool Validator::ContinueStatement(const sem::Statement* stmt,
sem::Statement* current_statement) const {
if (auto* continuing = ClosestContinuing(/*stop_at_loop*/ true, /* stop_at_switch */ false,
current_statement)) {
AddError(stmt->Declaration()->source)
<< "continuing blocks must not contain a continue statement";
if (continuing != stmt->Declaration() && continuing != stmt->Parent()->Declaration()) {
AddNote(continuing->source) << "see continuing block here";
}
return false;
}
if (!stmt->FindFirstParent<sem::LoopBlockStatement>()) {
AddError(stmt->Declaration()->source) << "continue statement must be in a loop";
return false;
}
return true;
}
bool Validator::Call(const sem::Call* call, sem::Statement* current_statement) const {
if (!call->Target()->MustUse()) {
return true;
}
auto* expr = call->Declaration();
bool is_call_stmt =
current_statement && Is<ast::CallStatement>(current_statement->Declaration(),
[&](auto* stmt) { return stmt->expr == expr; });
if (is_call_stmt) {
// Call target is annotated with @must_use, but was used as a call statement.
Switch(
call->Target(), //
[&](const sem::Function* fn) {
AddError(call->Declaration()->source)
<< "ignoring return value of function "
<< style::Function(fn->Declaration()->name->symbol.NameView())
<< " annotated with " << style::Attribute("@must_use");
sem_.NoteDeclarationSource(fn->Declaration());
},
[&](const sem::BuiltinFn* b) {
AddError(call->Declaration()->source)
<< "ignoring return value of builtin " << style::Function(b->Fn());
},
[&](const sem::ValueConversion*) {
AddError(call->Declaration()->source) << "value conversion evaluated but not used";
},
[&](const sem::ValueConstructor*) {
AddError(call->Declaration()->source) << "value constructor evaluated but not used";
},
[&](Default) {
AddError(call->Declaration()->source) << "return value of call not used";
});
return false;
}
return true;
}
bool Validator::LoopStatement(const sem::LoopStatement* stmt) const {
if (stmt->Behaviors().Empty()) {
AddError(stmt->Declaration()->source.Begin()) << "loop does not exit";
return false;
}
return true;
}
bool Validator::ForLoopStatement(const sem::ForLoopStatement* stmt) const {
if (stmt->Behaviors().Empty()) {
AddError(stmt->Declaration()->source.Begin()) << "for-loop does not exit";
return false;
}
if (auto* cond = stmt->Condition()) {
auto* cond_ty = cond->Type()->UnwrapRef();
if (!cond_ty->Is<core::type::Bool>()) {
AddError(stmt->Condition()->Declaration()->source)
<< "for-loop condition must be bool, got " << sem_.TypeNameOf(cond_ty);
return false;
}
}
return true;
}
bool Validator::WhileStatement(const sem::WhileStatement* stmt) const {
if (stmt->Behaviors().Empty()) {
AddError(stmt->Declaration()->source.Begin()) << "while does not exit";
return false;
}
if (auto* cond = stmt->Condition()) {
auto* cond_ty = cond->Type()->UnwrapRef();
if (!cond_ty->Is<core::type::Bool>()) {
AddError(stmt->Condition()->Declaration()->source)
<< "while condition must be bool, got " << sem_.TypeNameOf(cond_ty);
return false;
}
}
return true;
}
bool Validator::BreakIfStatement(const sem::BreakIfStatement* stmt,
sem::Statement* current_statement) const {
auto* cond_ty = stmt->Condition()->Type()->UnwrapRef();
if (!cond_ty->Is<core::type::Bool>()) {
AddError(stmt->Condition()->Declaration()->source)
<< "break-if statement condition must be bool, got " << sem_.TypeNameOf(cond_ty);
return false;
}
for (const auto* s = current_statement; s != nullptr; s = s->Parent()) {
if (s->Is<sem::LoopStatement>()) {
break;
}
if (auto* continuing = s->As<sem::LoopContinuingBlockStatement>()) {
if (continuing->Declaration()->statements.Back() != stmt->Declaration()) {
AddError(stmt->Declaration()->source)
<< "break-if must be the last statement in a continuing block";
AddNote(s->Declaration()->source) << "see continuing block here";
return false;
}
return true;
}
}
AddError(stmt->Declaration()->source) << "break-if must be in a continuing block";
return false;
}
bool Validator::IfStatement(const sem::IfStatement* stmt) const {
auto* cond_ty = stmt->Condition()->Type()->UnwrapRef();
if (!cond_ty->Is<core::type::Bool>()) {
AddError(stmt->Condition()->Declaration()->source)
<< "if statement condition must be bool, got " << sem_.TypeNameOf(cond_ty);
return false;
}
return true;
}
bool Validator::BuiltinCall(const sem::Call* call) const {
if (call->Type()->Is<core::type::Void>()) {
bool is_call_statement = false;
// Some built-in call are not owned by a statement, e.g. a built-in called in global
// variable declaration. Calling no-return-value built-in in these context is invalid as
// well.
if (auto* call_stmt = call->Stmt()) {
if (auto* call_stmt_ast = As<ast::CallStatement>(call_stmt->Declaration())) {
if (call_stmt_ast->expr == call->Declaration()) {
is_call_statement = true;
}
}
}
if (!is_call_statement) {
// https://gpuweb.github.io/gpuweb/wgsl/#function-call-expr
// If the called function does not return a value, a function call statement should be
// used instead.
auto* builtin = call->Target()->As<sem::BuiltinFn>();
AddError(call->Declaration()->source)
<< "builtin function " << style::Function(builtin->Fn())
<< " does not return a value";
return false;
}
}
return true;
}
bool Validator::TextureBuiltinFn(const sem::Call* call) const {
auto* builtin = call->Target()->As<sem::BuiltinFn>();
if (!builtin) {
return false;
}
std::string func_name = builtin->str();
auto& signature = builtin->Signature();
if (mode_ == wgsl::ValidationMode::kCompat) {
if (builtin->Fn() == wgsl::BuiltinFn::kTextureLoad) {
auto* arg = call->Arguments()[0];
if (arg->Type()
->IsAnyOf<core::type::DepthTexture, core::type::DepthMultisampledTexture>()) {
AddError(arg->Declaration()->source)
<< "use of " << arg->Type()->FriendlyName()
<< " with textureLoad is not allowed in compatibility mode";
return false;
}
}
}
auto check_arg_is_constexpr = [&](core::ParameterUsage usage, int min, int max) {
auto signed_index = signature.IndexOf(usage);
if (signed_index < 0) {
return true;
}
auto index = static_cast<size_t>(signed_index);
auto* arg = call->Arguments()[index];
if (auto values = arg->ConstantValue()) {
if (auto* vector = values->Type()->As<core::type::Vector>()) {
for (size_t i = 0; i < vector->Width(); i++) {
auto value = values->Index(i)->ValueAs<AInt>();
if (value < min || value > max) {
AddError(arg->Declaration()->source)
<< "each component of the " << usage << " argument must be at least "
<< min << " and at most " << max << ". " << usage << " component " << i
<< " is " << value;
return false;
}
}
} else {
auto value = values->ValueAs<AInt>();
if (value < min || value > max) {
AddError(arg->Declaration()->source)
<< "the " << usage << " argument must be at least " << min
<< " and at most " << max << ". " << usage << " is " << value;
return false;
}
}
return true;
}
AddError(arg->Declaration()->source)
<< "the " << usage << " argument must be a const-expression";
return false;
};
return check_arg_is_constexpr(core::ParameterUsage::kOffset, -8, 7) &&
check_arg_is_constexpr(core::ParameterUsage::kComponent, 0, 3);
}
bool Validator::WorkgroupUniformLoad(const sem::Call* call) const {
auto* builtin = call->Target()->As<sem::BuiltinFn>();
if (!builtin) {
return false;
}
TINT_ASSERT(call->Arguments().Length() > 0);
auto* arg = call->Arguments()[0];
auto* ptr = arg->Type()->As<core::type::Pointer>();
TINT_ASSERT(ptr != nullptr);
auto* ty = ptr->StoreType();
if (ty->Is<core::type::Atomic>() || atomic_composite_info_.Contains(ty)) {
AddError(arg->Declaration()->source)
<< "workgroupUniformLoad must not be called with an argument that "
"contains an atomic type";
return false;
}
return true;
}
bool Validator::SubgroupBroadcast(const sem::Call* call) const {
auto* builtin = call->Target()->As<sem::BuiltinFn>();
if (!builtin) {
return false;
}
TINT_ASSERT(call->Arguments().Length() == 2);
auto* id = call->Arguments()[1];
auto* constant_value = id->ConstantValue();
if (!constant_value) {
AddError(id->Declaration()->source)
<< "the sourceLaneIndex argument of subgroupBroadcast must be a const-expression";
return false;
}
if (id->Type()->IsSignedIntegerScalar() && constant_value->ValueAs<i32>() < 0) {
AddError(id->Declaration()->source) << "the sourceLaneIndex argument of subgroupBroadcast "
"must be greater than or equal to zero";
return false;
}
return true;
}
bool Validator::QuadBroadcast(const sem::Call* call) const {
auto* builtin = call->Target()->As<sem::BuiltinFn>();
if (!builtin) {
return false;
}
TINT_ASSERT(call->Arguments().Length() == 2);
auto* id = call->Arguments()[1];
auto* constant_value = id->ConstantValue();
if (!constant_value) {
AddError(id->Declaration()->source)
<< "the id argument of quadBroadcast must be a const-expression";
return false;
}
if (id->Type()->IsSignedIntegerScalar() && constant_value->ValueAs<i32>() < 0) {
AddError(id->Declaration()->source)
<< "the id argument of quadBroadcast must be greater than or equal to zero";
return false;
}
return true;
}
bool Validator::RequiredFeaturesForBuiltinFn(const sem::Call* call) const {
const auto* builtin = call->Target()->As<sem::BuiltinFn>();
if (!builtin) {
return true;
}
if (builtin->IsSubgroup()) {
// The `chromium_experimental_subgroups` extension enables all subgroup features. Otherwise,
// we need `subgroups`, or `subgroups_f16` for f16 functions.
if (!enabled_extensions_.Contains(wgsl::Extension::kChromiumExperimentalSubgroups)) {
auto ext = wgsl::Extension::kSubgroups;
if (builtin->ReturnType()->DeepestElement()->Is<core::type::F16>()) {
ext = wgsl::Extension::kSubgroupsF16;
}
if (!enabled_extensions_.Contains(ext)) {
AddError(call->Declaration()->source)
<< "cannot call built-in function " << style::Function(builtin->Fn())
<< " without extension " << style::Code(wgsl::ToString(ext));
return false;
}
}
}
const auto feature = builtin->RequiredLanguageFeature();
if (feature != wgsl::LanguageFeature::kUndefined) {
if (!allowed_features_.features.count(feature)) {
AddError(call->Declaration()->source)
<< "built-in function " << style::Function(builtin->Fn()) << " requires the "
<< style::Code(wgsl::ToString(feature))
<< " language feature, which is not allowed in the current environment";
return false;
}
}
return true;
}
bool Validator::CheckF16Enabled(const Source& source) const {
// Validate if f16 type is allowed.
if (!enabled_extensions_.Contains(wgsl::Extension::kF16)) {
AddError(source) << style::Type("f16") << " type used without " << style::Code("f16")
<< " extension enabled";
return false;
}
return true;
}
bool Validator::FunctionCall(const sem::Call* call, sem::Statement* current_statement) const {
auto* decl = call->Declaration();
auto* target = call->Target()->As<sem::Function>();
auto sym = target->Declaration()->name->symbol;
auto name = sym.Name();
if (!current_statement) { // Function call at module-scope.
AddError(decl->source) << "functions cannot be called at module-scope";
return false;
}
if (target->Declaration()->IsEntryPoint()) {
// https://www.w3.org/TR/WGSL/#function-restriction
// An entry point must never be the target of a function call.
AddError(decl->source) << "entry point functions cannot be the target of a function call";
return false;
}
if (decl->args.Length() != target->Parameters().Length()) {
bool more = decl->args.Length() > target->Parameters().Length();
AddError(decl->source) << "too "
<< (more ? std::string("many") : std::string("few")) +
" arguments in call to "
<< style::Function(name) << ", expected "
<< target->Parameters().Length() << ", got "
<< call->Arguments().Length();
return false;
}
for (size_t i = 0; i < call->Arguments().Length(); ++i) {
const sem::Variable* param = target->Parameters()[i];
const ast::Expression* arg_expr = decl->args[i];
auto* param_type = param->Type();
auto* arg_type = sem_.TypeOf(arg_expr)->UnwrapRef();
if (param_type != arg_type) {
AddError(arg_expr->source) << "type mismatch for argument " << (i + 1) << " in call to "
<< style::Function(name) << ", expected "
<< style::Type(sem_.TypeNameOf(param_type)) << ", got "
<< style::Type(sem_.TypeNameOf(arg_type));
return false;
}
if (param_type->Is<core::type::Pointer>() &&
!allowed_features_.features.count(
wgsl::LanguageFeature::kUnrestrictedPointerParameters)) {
// https://gpuweb.github.io/gpuweb/wgsl/#function-restriction
// Each argument of pointer type to a user-defined function must have the same memory
// view as its root identifier.
// We can validate this by just comparing the store type of the argument with that of
// its root identifier, as these will match iff the memory view is the same.
auto* arg_store_type = arg_type->As<core::type::Pointer>()->StoreType();
auto* root = call->Arguments()[i]->RootIdentifier();
auto* root_ptr_ty = root->Type()->As<core::type::Pointer>();
auto* root_ref_ty = root->Type()->As<core::type::Reference>();
TINT_ASSERT(root_ptr_ty || root_ref_ty);
const core::type::Type* root_store_type;
if (root_ptr_ty) {
root_store_type = root_ptr_ty->StoreType();
} else {
root_store_type = root_ref_ty->StoreType();
}
if (root_store_type != arg_store_type &&
IsValidationEnabled(param->Declaration()->attributes,
ast::DisabledValidation::kIgnoreInvalidPointerArgument)) {
AddError(arg_expr->source) << "arguments of pointer type must not point to a "
"subset of the originating variable";
return false;
}
}
}
if (call->Type()->Is<core::type::Void>()) {
bool is_call_statement = false;
if (auto* call_stmt = As<ast::CallStatement>(call->Stmt()->Declaration())) {
if (call_stmt->expr == call->Declaration()) {
is_call_statement = true;
}
}
if (!is_call_statement) {
// https://gpuweb.github.io/gpuweb/wgsl/#function-call-expr
// If the called function does not return a value, a function call
// statement should be used instead.
AddError(decl->source)
<< "function " << style::Function(name) << " does not return a value";
return false;
}
}
return true;
}
bool Validator::StructureInitializer(const ast::CallExpression* ctor,
const core::type::Struct* struct_type) const {
if (!struct_type->IsConstructible()) {
AddError(ctor->source) << "structure constructor has non-constructible type";
return false;
}
if (ctor->args.Length() > 0) {
if (ctor->args.Length() != struct_type->Members().Length()) {
std::string fm = ctor->args.Length() < struct_type->Members().Length() ? "few" : "many";
AddError(ctor->source)
<< "structure constructor has too " << fm << " inputs: expected "
<< struct_type->Members().Length() << ", found " << ctor->args.Length();
return false;
}
for (auto* member : struct_type->Members()) {
auto* value = ctor->args[member->Index()];
auto* value_ty = sem_.TypeOf(value);
if (member->Type() != value_ty->UnwrapRef()) {
AddError(value->source)
<< "type in structure constructor does not match struct member type: expected "
<< style::Type(sem_.TypeNameOf(member->Type())) << ", found "
<< style::Type(sem_.TypeNameOf(value_ty));
return false;
}
}
}
return true;
}
bool Validator::ArrayConstructor(const ast::CallExpression* ctor,
const sem::Array* array_type) const {
auto& values = ctor->args;
auto* elem_ty = array_type->ElemType();
for (auto* value : values) {
auto* value_ty = sem_.TypeOf(value)->UnwrapRef();
if (core::type::Type::ConversionRank(value_ty, elem_ty) ==
core::type::Type::kNoConversion) {
AddError(value->source) << style::Type(sem_.TypeNameOf(value_ty))
<< " cannot be used to construct an array of "
<< style::Type(sem_.TypeNameOf(elem_ty));
return false;
}
}
auto* c = array_type->Count();
if (c->Is<core::type::RuntimeArrayCount>()) {
AddError(ctor->source) << "cannot construct a runtime-sized array";
return false;
}
if (c->IsAnyOf<sem::NamedOverrideArrayCount, sem::UnnamedOverrideArrayCount>()) {
AddError(ctor->source) << "cannot construct an array that has an override-expression count";
return false;
}
if (!elem_ty->IsConstructible()) {
AddError(ctor->source) << "array constructor has non-constructible element type";
return false;
}
if (DAWN_UNLIKELY(!c->Is<core::type::ConstantArrayCount>())) {
TINT_ICE() << "Invalid ArrayCount found";
}
const auto count = c->As<core::type::ConstantArrayCount>()->value;
if (!values.IsEmpty() && (values.Length() != count)) {
std::string fm = values.Length() < count ? "few" : "many";
AddError(ctor->source) << "array constructor has too " << fm << " elements: expected "
<< count << ", found " << values.Length();
return false;
}
return true;
}
bool Validator::Vector(const core::type::Type* el_ty, const Source& source) const {
if (!el_ty->Is<core::type::Scalar>()) {
AddError(source) << "vector element type must be " << style::Type("bool") << ", "
<< style::Type("f32") << ", " << style::Type("f16") << ", "
<< style::Type("i32") << " or " << style::Type("u32");
return false;
}
return true;
}
bool Validator::Matrix(const core::type::Type* el_ty, const Source& source) const {
if (!el_ty->IsFloatScalar()) {
AddError(source) << "matrix element type must be " << style::Type("f32") << " or "
<< style::Type("f16");
return false;
}
return true;
}
bool Validator::PipelineStages(VectorRef<sem::Function*> entry_points) const {
auto var_source = [&](const sem::Function* func, const sem::GlobalVariable* var) {
for (auto* user : var->Users()) {
if (user->Stmt() && func == user->Stmt()->Function()) {
return user->Declaration()->source;
}
}
return Source();
};
auto backtrace = [&](const sem::Function* func, const sem::Function* entry_point) {
if (func != entry_point) {
TraverseCallChain(entry_point, func, [&](const sem::Function* f) {
AddNote(f->Declaration()->source)
<< "called by function "
<< style::Function(f->Declaration()->name->symbol.NameView());
});
AddNote(entry_point->Declaration()->source)
<< "called by entry point "
<< style::Function(entry_point->Declaration()->name->symbol.NameView());
}
};
auto check_var_uses = [&](const sem::Function* func, const sem::Function* entry_point) {
auto var_decl_note = [&](const sem::GlobalVariable* var) {
AddNote(var->Declaration()->source) << "variable is declared here";
backtrace(func, entry_point);
};
auto stage = entry_point->Declaration()->PipelineStage();
for (auto* var : func->DirectlyReferencedGlobals()) {
Source source = var_source(func, var);
if ((stage != ast::PipelineStage::kCompute &&
var->AddressSpace() == core::AddressSpace::kWorkgroup) ||
(stage != ast::PipelineStage::kFragment &&
var->AddressSpace() == core::AddressSpace::kPixelLocal)) {
AddError(source) << "var with " << style::Enum(var->AddressSpace())
<< " address space cannot be used by " << stage
<< " pipeline stage";
var_decl_note(var);
return false;
}
if (stage == ast::PipelineStage::kVertex &&
var->AddressSpace() == core::AddressSpace::kStorage &&
var->Access() != core::Access::kRead) {
AddError(source) << "var with " << style::Enum(var->AddressSpace())
<< " address space and " << style::Enum(var->Access())
<< " access mode cannot be used by " << stage << " pipeline stage";
var_decl_note(var);
return false;
}
auto* storage = var->Type()->UnwrapRef()->As<core::type::StorageTexture>();
if (stage == ast::PipelineStage::kVertex && storage &&
storage->Access() != core::Access::kRead) {
AddError(source) << "storage texture with " << style::Enum(storage->Access())
<< " access mode cannot be used by " << stage << " pipeline stage";
var_decl_note(var);
return false;
}
}
return true;
};
auto check_builtin_calls = [&](const sem::Function* func, const sem::Function* entry_point) {
auto stage = entry_point->Declaration()->PipelineStage();
for (auto* builtin : func->DirectlyCalledBuiltins()) {
if (!builtin->SupportedStages().Contains(stage)) {
auto* call = func->FindDirectCallTo(builtin);
AddError(call ? call->Declaration()->source : func->Declaration()->source)
<< "built-in cannot be used by " << stage << " pipeline stage";
backtrace(func, entry_point);
return false;
}
}
return true;
};
auto check_no_discards = [&](const sem::Function* func, const sem::Function* entry_point) {
if (auto* discard = func->DiscardStatement()) {
auto stage = entry_point->Declaration()->PipelineStage();
AddError(discard->Declaration()->source)
<< "discard statement cannot be used in " << stage << " pipeline stage";
backtrace(func, entry_point);
return false;
}
return true;
};
auto check_func = [&](const sem::Function* func, const sem::Function* entry_point) {
if (!check_var_uses(func, entry_point)) {
return false;
}
if (!check_builtin_calls(func, entry_point)) {
return false;
}
if (entry_point->Declaration()->PipelineStage() != ast::PipelineStage::kFragment) {
if (!check_no_discards(func, entry_point)) {
return false;
}
}
return true;
};
for (auto* entry_point : entry_points) {
if (!check_func(entry_point, entry_point)) {
return false;
}
for (auto* func : entry_point->TransitivelyCalledFunctions()) {
if (!check_func(func, entry_point)) {
return false;
}
}
}
return true;
}
bool Validator::ModuleScopeVarUsages(VectorRef<sem::Function*> entry_points) const {
for (auto* entry_point : entry_points) {
if (!CheckNoMultipleModuleScopeVarsOfAddressSpace(entry_point,
core::AddressSpace::kPushConstant)) {
return false;
}
if (!CheckNoMultipleModuleScopeVarsOfAddressSpace(entry_point,
core::AddressSpace::kPixelLocal)) {
return false;
}
}
return true;
}
bool Validator::Array(const sem::Array* arr, const Source& el_source) const {
auto* el_ty = arr->ElemType();
if (!IsPlain(el_ty)) {
AddError(el_source) << sem_.TypeNameOf(el_ty)
<< " cannot be used as an element type of an array";
return false;
}
if (!IsFixedFootprint(el_ty)) {
AddError(el_source) << "an array element type cannot contain a runtime-sized array";
return false;
}
if (IsArrayWithOverrideCount(el_ty)) {
RaiseArrayWithOverrideCountError(el_source);
return false;
}
return true;
}
bool Validator::ArrayStrideAttribute(const ast::StrideAttribute* attr,
uint32_t el_size,
uint32_t el_align) const {
auto stride = attr->stride;
bool is_valid_stride = (stride >= el_size) && (stride >= el_align) && (stride % el_align == 0);
if (!is_valid_stride) {
// https://gpuweb.github.io/gpuweb/wgsl/#array-layout-rules
// Arrays decorated with the stride attribute must have a stride that is
// at least the size of the element type, and be a multiple of the
// element type's alignment value.
AddError(attr->source)
<< "arrays decorated with the stride attribute must have a stride that is at least the "
"size of the element type, and be a multiple of the element type's alignment value";
return false;
}
return true;
}
bool Validator::Alias(const ast::Alias*) const {
return true;
}
bool Validator::Structure(const sem::Struct* str, ast::PipelineStage stage) const {
if (str->Members().IsEmpty()) {
AddError(str->Declaration()->name->source) << "structures must have at least one member";
return false;
}
std::bitset<2> blend_src_appearance_mask;
const ast::BlendSrcAttribute* first_blend_src = nullptr;
const core::type::Type* first_blend_src_type = nullptr;
const ast::LocationAttribute* first_location_without_blend_src = nullptr;
Hashset<std::pair<uint32_t, std::optional<uint32_t>>, 8> locations_and_blend_srcs;
Hashset<uint32_t, 4> colors;
for (auto* member : str->Members()) {
if (auto* r = member->Type()->As<sem::Array>()) {
if (r->Count()->Is<core::type::RuntimeArrayCount>()) {
if (member != str->Members().Back()) {
AddError(member->Declaration()->source)
<< "runtime arrays may only appear as the last member of a struct";
return false;
}
}
if (IsArrayWithOverrideCount(member->Type())) {
RaiseArrayWithOverrideCountError(member->Declaration()->type->source);
return false;
}
} else if (!IsFixedFootprint(member->Type())) {
AddError(member->Declaration()->source)
<< "a struct that contains a runtime array cannot be nested inside another struct";
return false;
}
auto has_position = false;
const ast::BlendSrcAttribute* blend_src_attribute = nullptr;
const ast::LocationAttribute* location_attribute = nullptr;
const ast::ColorAttribute* color_attribute = nullptr;
const ast::InvariantAttribute* invariant_attribute = nullptr;
const ast::InterpolateAttribute* interpolate_attribute = nullptr;
bool ignore_clip_distances_type = IsValidationDisabled(
member->Declaration()->attributes, ast::DisabledValidation::kIgnoreClipDistancesType);
for (auto* attr : member->Declaration()->attributes) {
bool ok = Switch(
attr, //
[&](const ast::InvariantAttribute* invariant) {
invariant_attribute = invariant;
return InvariantAttribute(invariant, stage);
},
[&](const ast::LocationAttribute* location) {
location_attribute = location;
TINT_ASSERT(member->Attributes().location.has_value());
return LocationAttribute(location, member->Type(), stage,
member->Declaration()->source);
},
[&](const ast::BlendSrcAttribute* blend_src) {
blend_src_attribute = blend_src;
return BlendSrcAttribute(blend_src, stage);
},
[&](const ast::ColorAttribute* color) {
color_attribute = color;
return ColorAttribute(color, member->Type(), stage,
member->Declaration()->source);
},
[&](const ast::BuiltinAttribute* builtin_attr) {
if (!BuiltinAttribute(builtin_attr, member->Type(), stage,
/* is_input */ false, ignore_clip_distances_type)) {
return false;
}
if (builtin_attr->builtin == core::BuiltinValue::kPosition) {
has_position = true;
}
return true;
},
[&](const ast::InterpolateAttribute* interpolate) {
interpolate_attribute = interpolate;
return InterpolateAttribute(interpolate, member->Type(), stage);
},
[&](const ast::StructMemberSizeAttribute*) {
if (!member->Type()->HasCreationFixedFootprint()) {
AddError(attr->source)
<< style::Attribute("@size")
<< " can only be applied to members where the member's type size can "
"be fully determined at shader creation time";
return false;
}
return true;
},
[&](Default) { return true; });
if (!ok) {
return false;
}
}
if (invariant_attribute && !has_position) {
AddError(invariant_attribute->source)
<< style::Attribute("@invariant") << " must be applied to a position builtin";
return false;
}
if (blend_src_attribute) {
if (member->Attributes().location.value_or(1) != 0) {
AddError(blend_src_attribute->source)
<< style::Attribute("@blend_src") << " can only be used with "
<< style::Attribute("@location") << style::Code("(", style::Literal("0"), ")");
return false;
}
if (first_blend_src == nullptr) {
first_blend_src = blend_src_attribute;
first_blend_src_type = member->Type();
} else if (!first_blend_src_type->Equals(*member->Type())) {
AddError(blend_src_attribute->source)
<< "All the outputs with " << style::Attribute("@blend_src")
<< " must have same type";
return false;
}
TINT_ASSERT(member->Attributes().blend_src.has_value() &&
*member->Attributes().blend_src <= 1u);
uint32_t blend_src = *member->Attributes().blend_src;
blend_src_appearance_mask.set(blend_src);
} else if (location_attribute) {
first_location_without_blend_src = location_attribute;
}
if (first_blend_src && first_location_without_blend_src) {
AddError(member->Declaration()->source)
<< style::Attribute("@blend_src") << " and " << style::Attribute("@location")
<< " are used on one member while another member with "
<< style::Attribute("@location") << " doesn't use "
<< style::Attribute("@blend_src");
return false;
}
if (interpolate_attribute && !location_attribute) {
AddError(interpolate_attribute->source)
<< style::Attribute("@interpolate") << " can only be used with "
<< style::Attribute("@location");
return false;
}
// Ensure all locations and optional blend_src pairs are unique
if (location_attribute) {
uint32_t location = member->Attributes().location.value();
std::optional<uint32_t> blend_src = member->Attributes().blend_src;
if (!locations_and_blend_srcs.Add(std::make_pair(location, blend_src))) {
auto& err = AddError(location_attribute->source)
<< style::Attribute("@location")
<< style::Code("(", style::Literal(location), ")");
if (blend_src) {
err << style::Attribute(" @blend_src")
<< style::Code("(", style::Literal(blend_src.value()), ")");
}
err << " appears multiple times";
return false;
}
}
if (color_attribute) {
uint32_t color = member->Attributes().color.value();
if (!colors.Add(color)) {
AddError(color_attribute->source)
<< style::Attribute("@color") << style::Code("(", style::Literal(color), ")")
<< " appears multiple times";
return false;
}
}
}
if (first_blend_src != nullptr && !blend_src_appearance_mask.all()) {
for (uint32_t i = 0; i < blend_src_appearance_mask.size(); ++i) {
if (!blend_src_appearance_mask.test(i)) {
AddError(first_blend_src->source)
<< style::Attribute("@blend_src") << style::Code("(", style::Literal(i), ")")
<< " is missing when " << style::Attribute("@blend_src") << " is used";
}
}
return false;
}
return true;
}
bool Validator::LocationAttribute(const ast::LocationAttribute* attr,
const core::type::Type* type,
ast::PipelineStage stage,
const Source& source) const {
if (stage == ast::PipelineStage::kCompute) {
AddError(attr->source) << style::Attribute("@", attr->Name())
<< " cannot be used by compute shaders";
return false;
}
if (!type->IsNumericScalarOrVector()) {
std::string invalid_type = sem_.TypeNameOf(type);
AddError(source) << "cannot apply " << style::Attribute("@location")
<< " to declaration of type " << style::Type(invalid_type);
AddNote(attr->source)
<< style::Attribute("@location")
<< " must only be applied to declarations of numeric scalar or numeric vector type";
return false;
}
return true;
}
bool Validator::ColorAttribute(const ast::ColorAttribute* attr,
const core::type::Type* type,
ast::PipelineStage stage,
const Source& source,
const std::optional<bool> is_input) const {
if (!enabled_extensions_.Contains(wgsl::Extension::kChromiumExperimentalFramebufferFetch)) {
AddError(attr->source) << "use of " << style::Attribute("@color")
<< " requires enabling extension "
<< style::Code("chromium_experimental_framebuffer_fetch");
return false;
}
bool is_stage_non_fragment =
stage != ast::PipelineStage::kNone && stage != ast::PipelineStage::kFragment;
bool is_output = !is_input.value_or(true);
if (is_stage_non_fragment || is_output) {
AddError(attr->source) << style::Attribute("@color")
<< " can only be used for fragment shader input";
return false;
}
if (!type->IsNumericScalarOrVector()) {
std::string invalid_type = sem_.TypeNameOf(type);
AddError(source) << "cannot apply " << style::Attribute("@color")
<< " to declaration of type " << style::Type(invalid_type);
AddNote(attr->source)
<< style::Attribute("@color")
<< " must only be applied to declarations of numeric scalar or numeric vector type";
return false;
}
return true;
}
bool Validator::BlendSrcAttribute(const ast::BlendSrcAttribute* attr,
ast::PipelineStage stage,
const std::optional<bool> is_input) const {
if (!enabled_extensions_.Contains(wgsl::Extension::kDualSourceBlending)) {
AddError(attr->source) << "use of " << style::Attribute("@blend_src")
<< " requires enabling extension "
<< style::Code("dual_source_blending");
return false;
}
bool is_stage_non_fragment =
stage != ast::PipelineStage::kNone && stage != ast::PipelineStage::kFragment;
bool is_input_param = is_input.value_or(false);
if (is_stage_non_fragment || is_input_param) {
AddError(attr->source) << style::Attribute("@", attr->Name())
<< " can only be used for fragment shader output";
return false;
}
return true;
}
bool Validator::Return(const ast::ReturnStatement* ret,
const core::type::Type* func_type,
const core::type::Type* ret_type,
sem::Statement* current_statement) const {
if (func_type->UnwrapRef() != ret_type) {
AddError(ret->source)
<< "return statement type must match its function return type, returned "
<< style::Type(sem_.TypeNameOf(ret_type)) << ", expected "
<< style::Type(sem_.TypeNameOf(func_type));
return false;
}
auto* sem = sem_.Get(ret);
if (auto* continuing = ClosestContinuing(/*stop_at_loop*/ false, /* stop_at_switch */ false,
current_statement)) {
AddError(ret->source) << "continuing blocks must not contain a return statement";
if (continuing != sem->Declaration() && continuing != sem->Parent()->Declaration()) {
AddNote(continuing->source) << "see continuing block here";
}
return false;
}
return true;
}
bool Validator::SwitchStatement(const ast::SwitchStatement* s) {
if (s->body.Length() > kMaxSwitchCaseSelectors) {
AddError(s->source) << "switch statement has " << s->body.Length()
<< " case selectors, max is " << kMaxSwitchCaseSelectors;
return false;
}
auto* cond_ty = sem_.TypeOf(s->condition);
if (!cond_ty->IsIntegerScalar()) {
AddError(s->condition->source)
<< "switch statement selector expression must be of a scalar integer type";
return false;
}
const sem::CaseSelector* default_selector = nullptr;
Hashmap<int64_t, Source, 4> selectors;
for (auto* case_stmt : s->body) {
auto* case_sem = sem_.Get<sem::CaseStatement>(case_stmt);
for (auto* selector : case_sem->Selectors()) {
if (selector->IsDefault()) {
if (default_selector != nullptr) {
// More than one default clause
AddError(selector->Declaration()->source)
<< "switch statement must have exactly one default clause";
AddNote(default_selector->Declaration()->source) << "previous default case";
return false;
}
default_selector = selector;
continue;
}
auto* decl_ty = selector->Value()->Type();
if (cond_ty != decl_ty) {
AddError(selector->Declaration()->source)
<< "the case selector values must have the same type as the "
"selector expression.";
return false;
}
auto value = selector->Value()->ValueAs<u32>();
if (auto added = selectors.Add(value, selector->Declaration()->source); !added) {
auto& err = AddError(selector->Declaration()->source)
<< "duplicate switch case " << style::Literal;
if (decl_ty->IsAnyOf<core::type::I32, core::type::AbstractNumeric>()) {
err << i32(value);
} else {
err << value;
}
AddNote(added.value) << "previous case declared here";
return false;
}
}
}
if (default_selector == nullptr) {
// No default clause
AddError(s->source) << "switch statement must have a default clause";
return false;
}
return true;
}
bool Validator::Assignment(const ast::Statement* a, const core::type::Type* rhs_ty) const {
const ast::Expression* lhs;
const ast::Expression* rhs;
if (auto* assign = a->As<ast::AssignmentStatement>()) {
lhs = assign->lhs;
rhs = assign->rhs;
} else if (auto* compound = a->As<ast::CompoundAssignmentStatement>()) {
lhs = compound->lhs;
rhs = compound->rhs;
if (!BinaryExpression(a, compound->op, sem_.GetVal(lhs), sem_.GetVal(rhs))) {
return false;
}
} else {
TINT_ICE() << "invalid assignment statement";
}
if (lhs->Is<ast::PhonyExpression>()) {
// https://www.w3.org/TR/WGSL/#phony-assignment-section
auto* ty = rhs_ty->UnwrapRef();
if (!ty->IsConstructible() &&
!ty->IsAnyOf<core::type::Pointer, core::type::Texture, core::type::Sampler,
core::type::AbstractNumeric>()) {
AddError(rhs->source)
<< "cannot assign " << style::Type(sem_.TypeNameOf(rhs_ty)) << " to "
<< style::Code("_") << ". " << style::Code("_")
<< " can only be assigned a constructible, pointer, texture or sampler type";
return false;
}
return true; // RHS can be anything.
}
// https://gpuweb.github.io/gpuweb/wgsl/#assignment-statement
auto const* lhs_sem = sem_.GetVal(lhs);
auto const* lhs_ty = lhs_sem->Type();
auto* lhs_ref = lhs_ty->As<core::type::Reference>();
if (!lhs_ref) {
// LHS is not a reference, so it has no storage.
AddError(lhs->source) << "cannot assign to " << sem_.Describe(lhs_sem);
auto* expr = lhs;
while (expr) {
expr = Switch(
expr, //
[&](const ast::AccessorExpression* e) { return e->object; },
[&](const ast::IdentifierExpression* i) {
if (auto user = sem_.Get<sem::VariableUser>(i)) {
Switch(
user->Variable()->Declaration(), //
[&](const ast::Let* v) {
AddNote(user->Declaration()->source)
<< style::Variable("let") << " variables are immutable";
sem_.NoteDeclarationSource(v);
},
[&](const ast::Const* v) {
AddNote(user->Declaration()->source)
<< style::Variable("const") << " variables are immutable";
sem_.NoteDeclarationSource(v);
},
[&](const ast::Override* v) {
AddNote(user->Declaration()->source)
<< style::Variable("override") << " variables are immutable";
sem_.NoteDeclarationSource(v);
},
[&](const ast::Parameter* v) {
AddNote(user->Declaration()->source) << "parameters are immutable";
sem_.NoteDeclarationSource(v);
});
}
return nullptr;
});
}
return false;
}
auto* storage_ty = lhs_ref->StoreType();
auto* value_type = rhs_ty->UnwrapRef(); // Implicit load of RHS
// Value type has to match storage type
if (storage_ty != value_type) {
AddError(a->source) << "cannot assign " << style::Type(sem_.TypeNameOf(rhs_ty)) << " to "
<< style::Type(sem_.TypeNameOf(lhs_ty));
return false;
}
if (!storage_ty->IsConstructible()) {
AddError(a->source) << "storage type of assignment must be constructible";
return false;
}
if (lhs_ref->Access() == core::Access::kRead) {
AddError(a->source) << "cannot store into a read-only type "
<< style::Type(sem_.RawTypeNameOf(lhs_ty));
return false;
}
return true;
}
bool Validator::IncrementDecrementStatement(const ast::IncrementDecrementStatement* inc) const {
const ast::Expression* lhs = inc->lhs;
// https://gpuweb.github.io/gpuweb/wgsl/#increment-decrement
if (auto* var_user = sem_.Get<sem::VariableUser>(lhs)) {
auto* v = var_user->Variable()->Declaration();
bool errored = Switch(
v, //
[&](const ast::Parameter*) {
AddError(lhs->source) << "cannot modify function parameter";
return true;
},
[&](const ast::Let*) {
AddError(lhs->source) << "cannot modify " << style::Keyword("let");
return true;
},
[&](const ast::Override*) {
AddError(lhs->source) << "cannot modify " << style::Keyword("override");
return true;
});
if (errored) {
sem_.NoteDeclarationSource(v);
return false;
}
}
auto const* lhs_ty = sem_.TypeOf(lhs);
auto* lhs_ref = lhs_ty->As<core::type::Reference>();
if (!lhs_ref) {
// LHS is not a reference, so it has no storage.
AddError(lhs->source) << "cannot modify value of type "
<< style::Type(sem_.TypeNameOf(lhs_ty));
return false;
}
if (!lhs_ref->StoreType()->IsIntegerScalar()) {
const std::string kind = inc->increment ? "increment" : "decrement";
AddError(lhs->source) << kind << " statement can only be applied to an integer scalar";
return false;
}
if (lhs_ref->Access() == core::Access::kRead) {
AddError(inc->source) << "cannot modify read-only type "
<< style::Type(sem_.RawTypeNameOf(lhs_ty));
return false;
}
return true;
}
bool Validator::NoDuplicateAttributes(VectorRef<const ast::Attribute*> attributes) const {
Hashmap<const tint::TypeInfo*, Source, 8> seen;
tint::Vector<const ast::DiagnosticControl*, 8> diagnostic_controls;
for (auto* d : attributes) {
if (auto* diag = d->As<ast::DiagnosticAttribute>()) {
// Allow duplicate diagnostic attributes, and check for conflicts later.
diagnostic_controls.Push(&diag->control);
} else {
auto added = seen.Add(&d->TypeInfo(), d->source);
if (!added && !d->Is<ast::InternalAttribute>()) {
AddError(d->source) << "duplicate " << d->Name() << " attribute";
AddNote(added.value) << "first attribute declared here";
return false;
}
}
}
return DiagnosticControls(diagnostic_controls, "attribute", DiagnosticDuplicates::kDenied);
}
bool Validator::DiagnosticControls(VectorRef<const ast::DiagnosticControl*> controls,
const char* use,
DiagnosticDuplicates allow_duplicates) const {
// Make sure that no two diagnostic controls conflict.
// They conflict if the rule name is the same and the severity is different.
Hashmap<std::pair<Symbol, Symbol>, const ast::DiagnosticControl*, 8> diagnostics;
for (auto* dc : controls) {
auto category = dc->rule_name->category ? dc->rule_name->category->symbol : Symbol();
auto name = dc->rule_name->name->symbol;
auto diag_added = diagnostics.Add(std::make_pair(category, name), dc);
if (!diag_added) {
if (diag_added.value->severity != dc->severity) {
AddError(dc->rule_name->source) << "conflicting diagnostic " << use;
AddNote(diag_added.value->rule_name->source)
<< "severity of " << style::Code(dc->rule_name->String()) << " set to "
<< style::Code(dc->severity) << " here";
return false;
} else if (allow_duplicates == DiagnosticDuplicates::kDenied) {
AddError(dc->rule_name->source) << "duplicate diagnostic " << use;
AddNote(diag_added.value->rule_name->source) << "first " << use << " declared here";
return false;
}
}
}
return true;
}
bool Validator::IsValidationDisabled(VectorRef<const ast::Attribute*> attributes,
ast::DisabledValidation validation) const {
for (auto* attribute : attributes) {
if (auto* dv = attribute->As<ast::DisableValidationAttribute>()) {
if (dv->validation == validation) {
return true;
}
}
}
return false;
}
bool Validator::IsValidationEnabled(VectorRef<const ast::Attribute*> attributes,
ast::DisabledValidation validation) const {
return !IsValidationDisabled(attributes, validation);
}
bool Validator::IsArrayWithOverrideCount(const core::type::Type* ty) const {
if (auto* arr = ty->UnwrapRef()->As<sem::Array>()) {
if (arr->Count()->IsAnyOf<sem::NamedOverrideArrayCount, sem::UnnamedOverrideArrayCount>()) {
return true;
}
}
return false;
}
void Validator::RaiseArrayWithOverrideCountError(const Source& source) const {
AddError(source) << style::Type("array") << " with an " << style::Keyword("override")
<< " element count can only be used as the store type of a "
<< style::Keyword("var") << style::Code("<", style::Enum("workgroup"), ">");
}
std::string Validator::VectorPretty(uint32_t size, const core::type::Type* element_type) const {
core::type::Vector vec_type(element_type, size);
return vec_type.FriendlyName();
}
bool Validator::CheckTypeAccessAddressSpace(const core::type::Type* store_ty,
core::Access access,
core::AddressSpace address_space,
VectorRef<const tint::ast::Attribute*> attributes,
const Source& source) const {
if (!AddressSpaceLayout(store_ty, address_space, source)) {
return false;
}
switch (address_space) {
case core::AddressSpace::kPixelLocal:
if (auto* str = store_ty->As<sem::Struct>()) {
for (auto* member : str->Members()) {
using Allowed = std::tuple<core::type::I32, core::type::U32, core::type::F32>;
if (DAWN_UNLIKELY(!member->Type()->TypeInfo().IsAnyOfTuple<Allowed>())) {
AddError(member->Declaration()->source)
<< style::Keyword("struct") << " members used in the "
<< style::Enum("pixel_local")
<< " address space can only be of the type " << style::Type("i32")
<< ", " << style::Type("u32") << " or " << style::Type("f32");
AddNote(source) << style::Keyword("struct ")
<< style::Type(str->Name().Name()) << " used in the "
<< style::Enum("pixel_local") << " address space here";
return false;
}
}
} else if (DAWN_UNLIKELY(!store_ty->TypeInfo().Is<core::type::Struct>())) {
AddError(source) << style::Enum("pixel_local")
<< " variable only support struct storage types";
return false;
}
break;
case core::AddressSpace::kPushConstant:
if (DAWN_UNLIKELY(!enabled_extensions_.Contains(
wgsl::Extension::kChromiumExperimentalPushConstant) &&
IsValidationEnabled(attributes,
ast::DisabledValidation::kIgnoreAddressSpace))) {
AddError(source) << "use of variable address space " << style::Enum("push_constant")
<< " requires enabling extension "
<< style::Code("chromium_experimental_push_constant");
return false;
}
break;
case core::AddressSpace::kStorage:
if (DAWN_UNLIKELY(access == core::Access::kWrite)) {
// The access mode for the storage address space can only be 'read' or 'read_write'.
AddError(source) << "access mode " << style::Enum("write")
<< " is not valid for the " << style::Enum("storage")
<< " address space";
return false;
}
break;
default:
break;
}
auto atomic_error = [&] {
StyledText err;
if (address_space != core::AddressSpace::kStorage &&
address_space != core::AddressSpace::kWorkgroup) {
AddError(source) << style::Type("atomic") << " variables must have "
<< style::Enum("storage") << " or " << style::Enum("workgroup")
<< " address space";
return true;
}
if (address_space == core::AddressSpace::kStorage && access != core::Access::kReadWrite) {
AddError(source) << "atomic variables in " << style::Enum("storage")
<< " address space must have " << style::Enum("read_write")
<< " access mode";
return true;
}
return false;
};
auto check_sub_atomics = [&] {
if (auto atomic_use = atomic_composite_info_.Get(store_ty)) {
if (DAWN_UNLIKELY(atomic_error())) {
AddNote(**atomic_use)
<< "atomic sub-type of " << style::Type(sem_.TypeNameOf(store_ty))
<< " is declared here";
return false;
}
}
return true;
};
return Switch(
store_ty, //
[&](const core::type::Atomic*) {
if (DAWN_UNLIKELY(atomic_error())) {
return false;
}
return true;
},
[&](const core::type::Struct*) { return check_sub_atomics(); }, //
[&](const sem::Array*) { return check_sub_atomics(); }, //
[&](Default) { return true; });
}
bool Validator::CheckNoMultipleModuleScopeVarsOfAddressSpace(sem::Function* entry_point,
core::AddressSpace space) const {
// State checked and modified by check() so that it remembers previously seen push_constant
// variables for an entry-point.
const sem::Variable* seen_var = nullptr;
const sem::Function* seen_func = nullptr;
auto check = [&](const sem::Function* func, const sem::Function* ep) {
for (auto* var : func->DirectlyReferencedGlobals()) {
if (var->AddressSpace() != space || var == seen_var) {
continue;
}
if (seen_var == nullptr) {
seen_var = var;
seen_func = func;
continue;
}
AddError(ep->Declaration()->source)
<< "entry point " << style::Function(ep->Declaration()->name->symbol.NameView())
<< " uses two different " << style::Enum(space) << " variables.";
AddNote(var->Declaration()->source)
<< "first " << style::Enum(space) << " variable declaration is here";
if (func != ep) {
TraverseCallChain(ep, func, [&](const sem::Function* f) {
AddNote(f->Declaration()->source)
<< "called by function "
<< style::Function(f->Declaration()->name->symbol.NameView());
});
AddNote(ep->Declaration()->source)
<< "called by entry point "
<< style::Function(ep->Declaration()->name->symbol.NameView());
}
AddNote(seen_var->Declaration()->source)
<< "second " << style::Enum(space) << " variable declaration is here";
if (seen_func != ep) {
TraverseCallChain(ep, seen_func, [&](const sem::Function* f) {
AddNote(f->Declaration()->source)
<< "called by function "
<< style::Function(f->Declaration()->name->symbol.NameView());
});
AddNote(ep->Declaration()->source)
<< "called by entry point "
<< style::Function(ep->Declaration()->name->symbol.NameView());
}
return false;
}
return true;
};
if (!check(entry_point, entry_point)) {
return false;
}
for (auto* func : entry_point->TransitivelyCalledFunctions()) {
if (!check(func, entry_point)) {
return false;
}
}
return true;
}
} // namespace tint::resolver