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// Copyright 2020 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "src/tint/resolver/resolver.h"
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <limits>
#include <utility>
#include "src/tint/ast/alias.h"
#include "src/tint/ast/array.h"
#include "src/tint/ast/assignment_statement.h"
#include "src/tint/ast/bitcast_expression.h"
#include "src/tint/ast/break_statement.h"
#include "src/tint/ast/call_statement.h"
#include "src/tint/ast/continue_statement.h"
#include "src/tint/ast/depth_texture.h"
#include "src/tint/ast/disable_validation_attribute.h"
#include "src/tint/ast/discard_statement.h"
#include "src/tint/ast/fallthrough_statement.h"
#include "src/tint/ast/for_loop_statement.h"
#include "src/tint/ast/id_attribute.h"
#include "src/tint/ast/if_statement.h"
#include "src/tint/ast/internal_attribute.h"
#include "src/tint/ast/interpolate_attribute.h"
#include "src/tint/ast/loop_statement.h"
#include "src/tint/ast/matrix.h"
#include "src/tint/ast/pointer.h"
#include "src/tint/ast/return_statement.h"
#include "src/tint/ast/sampled_texture.h"
#include "src/tint/ast/sampler.h"
#include "src/tint/ast/storage_texture.h"
#include "src/tint/ast/switch_statement.h"
#include "src/tint/ast/traverse_expressions.h"
#include "src/tint/ast/type_name.h"
#include "src/tint/ast/unary_op_expression.h"
#include "src/tint/ast/variable_decl_statement.h"
#include "src/tint/ast/vector.h"
#include "src/tint/ast/while_statement.h"
#include "src/tint/ast/workgroup_attribute.h"
#include "src/tint/resolver/uniformity.h"
#include "src/tint/sem/abstract_float.h"
#include "src/tint/sem/abstract_int.h"
#include "src/tint/sem/array.h"
#include "src/tint/sem/atomic.h"
#include "src/tint/sem/call.h"
#include "src/tint/sem/depth_multisampled_texture.h"
#include "src/tint/sem/depth_texture.h"
#include "src/tint/sem/for_loop_statement.h"
#include "src/tint/sem/function.h"
#include "src/tint/sem/if_statement.h"
#include "src/tint/sem/index_accessor_expression.h"
#include "src/tint/sem/loop_statement.h"
#include "src/tint/sem/materialize.h"
#include "src/tint/sem/member_accessor_expression.h"
#include "src/tint/sem/module.h"
#include "src/tint/sem/multisampled_texture.h"
#include "src/tint/sem/pointer.h"
#include "src/tint/sem/reference.h"
#include "src/tint/sem/sampled_texture.h"
#include "src/tint/sem/sampler.h"
#include "src/tint/sem/statement.h"
#include "src/tint/sem/storage_texture.h"
#include "src/tint/sem/struct.h"
#include "src/tint/sem/switch_statement.h"
#include "src/tint/sem/type_constructor.h"
#include "src/tint/sem/type_conversion.h"
#include "src/tint/sem/variable.h"
#include "src/tint/sem/while_statement.h"
#include "src/tint/utils/defer.h"
#include "src/tint/utils/math.h"
#include "src/tint/utils/reverse.h"
#include "src/tint/utils/scoped_assignment.h"
#include "src/tint/utils/transform.h"
namespace tint::resolver {
Resolver::Resolver(ProgramBuilder* builder)
: builder_(builder),
diagnostics_(builder->Diagnostics()),
const_eval_(*builder),
intrinsic_table_(IntrinsicTable::Create(*builder)),
sem_(builder, dependencies_),
validator_(builder, sem_) {}
Resolver::~Resolver() = default;
bool Resolver::Resolve() {
if (builder_->Diagnostics().contains_errors()) {
return false;
}
// Pre-allocate the ast -> sem map with the total number of AST nodes.
builder_->Sem().Reserve(builder_->ASTNodes().Count());
if (!DependencyGraph::Build(builder_->AST(), builder_->Symbols(), builder_->Diagnostics(),
dependencies_)) {
return false;
}
bool result = ResolveInternal();
if (!result && !diagnostics_.contains_errors()) {
TINT_ICE(Resolver, diagnostics_) << "resolving failed, but no error was raised";
return false;
}
// Create the semantic module
builder_->Sem().SetModule(builder_->create<sem::Module>(
std::move(dependencies_.ordered_globals), std::move(enabled_extensions_)));
return result;
}
bool Resolver::ResolveInternal() {
Mark(&builder_->AST());
// Process all module-scope declarations in dependency order.
for (auto* decl : dependencies_.ordered_globals) {
Mark(decl);
if (!Switch<bool>(
decl, //
[&](const ast::Enable* e) { return Enable(e); },
[&](const ast::TypeDecl* td) { return TypeDecl(td); },
[&](const ast::Function* func) { return Function(func); },
[&](const ast::Variable* var) { return GlobalVariable(var); },
[&](Default) {
TINT_UNREACHABLE(Resolver, diagnostics_)
<< "unhandled global declaration: " << decl->TypeInfo().name;
return false;
})) {
return false;
}
}
AllocateOverridableConstantIds();
SetShadows();
if (!validator_.PipelineStages(entry_points_)) {
return false;
}
if (!enabled_extensions_.contains(ast::Extension::kChromiumDisableUniformityAnalysis)) {
if (!AnalyzeUniformity(builder_, dependencies_)) {
// TODO(jrprice): Reject programs that fail uniformity analysis.
}
}
bool result = true;
for (auto* node : builder_->ASTNodes().Objects()) {
if (marked_.count(node) == 0) {
TINT_ICE(Resolver, diagnostics_)
<< "AST node '" << node->TypeInfo().name << "' was not reached by the resolver\n"
<< "At: " << node->source << "\n"
<< "Pointer: " << node;
result = false;
}
}
return result;
}
sem::Type* Resolver::Type(const ast::Type* ty) {
Mark(ty);
auto* s = Switch(
ty, //
[&](const ast::Void*) { return builder_->create<sem::Void>(); },
[&](const ast::Bool*) { return builder_->create<sem::Bool>(); },
[&](const ast::I32*) { return builder_->create<sem::I32>(); },
[&](const ast::U32*) { return builder_->create<sem::U32>(); },
[&](const ast::F16* t) -> sem::F16* {
// Validate if f16 type is allowed.
if (!enabled_extensions_.contains(ast::Extension::kF16)) {
AddError("f16 used without 'f16' extension enabled", t->source);
return nullptr;
}
return builder_->create<sem::F16>();
},
[&](const ast::F32*) { return builder_->create<sem::F32>(); },
[&](const ast::Vector* t) -> sem::Vector* {
if (!t->type) {
AddError("missing vector element type", t->source.End());
return nullptr;
}
if (auto* el = Type(t->type)) {
if (auto* vector = builder_->create<sem::Vector>(el, t->width)) {
if (validator_.Vector(vector, t->source)) {
return vector;
}
}
}
return nullptr;
},
[&](const ast::Matrix* t) -> sem::Matrix* {
if (!t->type) {
AddError("missing matrix element type", t->source.End());
return nullptr;
}
if (auto* el = Type(t->type)) {
if (auto* column_type = builder_->create<sem::Vector>(el, t->rows)) {
if (auto* matrix = builder_->create<sem::Matrix>(column_type, t->columns)) {
if (validator_.Matrix(matrix, t->source)) {
return matrix;
}
}
}
}
return nullptr;
},
[&](const ast::Array* t) { return Array(t); },
[&](const ast::Atomic* t) -> sem::Atomic* {
if (auto* el = Type(t->type)) {
auto* a = builder_->create<sem::Atomic>(el);
if (!validator_.Atomic(t, a)) {
return nullptr;
}
return a;
}
return nullptr;
},
[&](const ast::Pointer* t) -> sem::Pointer* {
if (auto* el = Type(t->type)) {
auto access = t->access;
if (access == ast::kUndefined) {
access = DefaultAccessForStorageClass(t->storage_class);
}
return builder_->create<sem::Pointer>(el, t->storage_class, access);
}
return nullptr;
},
[&](const ast::Sampler* t) { return builder_->create<sem::Sampler>(t->kind); },
[&](const ast::SampledTexture* t) -> sem::SampledTexture* {
if (auto* el = Type(t->type)) {
auto* sem = builder_->create<sem::SampledTexture>(t->dim, el);
if (!validator_.SampledTexture(sem, t->source)) {
return nullptr;
}
return sem;
}
return nullptr;
},
[&](const ast::MultisampledTexture* t) -> sem::MultisampledTexture* {
if (auto* el = Type(t->type)) {
auto* sem = builder_->create<sem::MultisampledTexture>(t->dim, el);
if (!validator_.MultisampledTexture(sem, t->source)) {
return nullptr;
}
return sem;
}
return nullptr;
},
[&](const ast::DepthTexture* t) { return builder_->create<sem::DepthTexture>(t->dim); },
[&](const ast::DepthMultisampledTexture* t) {
return builder_->create<sem::DepthMultisampledTexture>(t->dim);
},
[&](const ast::StorageTexture* t) -> sem::StorageTexture* {
if (auto* el = Type(t->type)) {
if (!validator_.StorageTexture(t)) {
return nullptr;
}
return builder_->create<sem::StorageTexture>(t->dim, t->format, t->access, el);
}
return nullptr;
},
[&](const ast::ExternalTexture*) { return builder_->create<sem::ExternalTexture>(); },
[&](Default) {
auto* resolved = sem_.ResolvedSymbol(ty);
return Switch(
resolved, //
[&](sem::Type* type) { return type; },
[&](sem::Variable* var) {
auto name = builder_->Symbols().NameFor(var->Declaration()->symbol);
AddError("cannot use variable '" + name + "' as type", ty->source);
AddNote("'" + name + "' declared here", var->Declaration()->source);
return nullptr;
},
[&](sem::Function* func) {
auto name = builder_->Symbols().NameFor(func->Declaration()->symbol);
AddError("cannot use function '" + name + "' as type", ty->source);
AddNote("'" + name + "' declared here", func->Declaration()->source);
return nullptr;
},
[&](Default) {
if (auto* tn = ty->As<ast::TypeName>()) {
if (IsBuiltin(tn->name)) {
auto name = builder_->Symbols().NameFor(tn->name);
AddError("cannot use builtin '" + name + "' as type", ty->source);
return nullptr;
}
}
TINT_UNREACHABLE(Resolver, diagnostics_)
<< "Unhandled resolved type '"
<< (resolved ? resolved->TypeInfo().name : "<null>")
<< "' resolved from ast::Type '" << ty->TypeInfo().name << "'";
return nullptr;
});
});
if (s) {
builder_->Sem().Add(ty, s);
}
return s;
}
sem::Variable* Resolver::Variable(const ast::Variable* v, bool is_global) {
return Switch(
v, //
[&](const ast::Var* var) { return Var(var, is_global); },
[&](const ast::Let* let) { return Let(let, is_global); },
[&](const ast::Override* override) { return Override(override); },
[&](const ast::Const* const_) { return Const(const_, is_global); },
[&](Default) {
TINT_ICE(Resolver, diagnostics_)
<< "Resolver::GlobalVariable() called with a unknown variable type: "
<< v->TypeInfo().name;
return nullptr;
});
}
sem::Variable* Resolver::Let(const ast::Let* v, bool is_global) {
const sem::Type* ty = nullptr;
// If the variable has a declared type, resolve it.
if (v->type) {
ty = Type(v->type);
if (!ty) {
return nullptr;
}
}
if (!v->constructor) {
AddError("'let' declaration must have an initializer", v->source);
return nullptr;
}
auto* rhs = Materialize(Expression(v->constructor), ty);
if (!rhs) {
return nullptr;
}
// If the variable has no declared type, infer it from the RHS
if (!ty) {
ty = rhs->Type()->UnwrapRef(); // Implicit load of RHS
}
if (rhs && !validator_.VariableInitializer(v, ast::StorageClass::kNone, ty, rhs)) {
return nullptr;
}
if (!ApplyStorageClassUsageToType(ast::StorageClass::kNone, const_cast<sem::Type*>(ty),
v->source)) {
AddNote("while instantiating 'let' " + builder_->Symbols().NameFor(v->symbol), v->source);
return nullptr;
}
sem::Variable* sem = nullptr;
if (is_global) {
sem = builder_->create<sem::GlobalVariable>(
v, ty, sem::EvaluationStage::kRuntime, ast::StorageClass::kNone,
ast::Access::kUndefined, /* constant_value */ nullptr, sem::BindingPoint{});
} else {
sem = builder_->create<sem::LocalVariable>(v, ty, sem::EvaluationStage::kRuntime,
ast::StorageClass::kNone,
ast::Access::kUndefined, current_statement_,
/* constant_value */ nullptr);
}
sem->SetConstructor(rhs);
builder_->Sem().Add(v, sem);
return sem;
}
sem::Variable* Resolver::Override(const ast::Override* v) {
const sem::Type* ty = nullptr;
// If the variable has a declared type, resolve it.
if (v->type) {
ty = Type(v->type);
if (!ty) {
return nullptr;
}
}
const sem::Expression* rhs = nullptr;
// Does the variable have a constructor?
if (v->constructor) {
rhs = Materialize(Expression(v->constructor), ty);
if (!rhs) {
return nullptr;
}
// If the variable has no declared type, infer it from the RHS
if (!ty) {
ty = rhs->Type()->UnwrapRef(); // Implicit load of RHS
}
} else if (!ty) {
AddError("override declaration requires a type or initializer", v->source);
return nullptr;
}
if (rhs && !validator_.VariableInitializer(v, ast::StorageClass::kNone, ty, rhs)) {
return nullptr;
}
if (!ApplyStorageClassUsageToType(ast::StorageClass::kNone, const_cast<sem::Type*>(ty),
v->source)) {
AddNote("while instantiating 'override' " + builder_->Symbols().NameFor(v->symbol),
v->source);
return nullptr;
}
auto* sem = builder_->create<sem::GlobalVariable>(
v, ty, sem::EvaluationStage::kOverride, ast::StorageClass::kNone, ast::Access::kUndefined,
/* constant_value */ nullptr, sem::BindingPoint{});
if (auto* id = ast::GetAttribute<ast::IdAttribute>(v->attributes)) {
sem->SetConstantId(static_cast<uint16_t>(id->value));
}
sem->SetConstructor(rhs);
builder_->Sem().Add(v, sem);
return sem;
}
sem::Variable* Resolver::Const(const ast::Const* c, bool is_global) {
const sem::Type* ty = nullptr;
// If the variable has a declared type, resolve it.
if (c->type) {
ty = Type(c->type);
if (!ty) {
return nullptr;
}
}
if (!c->constructor) {
AddError("'const' declaration must have an initializer", c->source);
return nullptr;
}
const auto* rhs = Expression(c->constructor);
if (!rhs) {
return nullptr;
}
if (ty) {
// If an explicit type was specified, materialize to that type
rhs = Materialize(rhs, ty);
if (!rhs) {
return nullptr;
}
} else {
// If no type was specified, infer it from the RHS
ty = rhs->Type();
}
const auto value = rhs->ConstantValue();
if (!value) {
AddError("'const' initializer must be constant expression", c->constructor->source);
return nullptr;
}
if (!validator_.VariableInitializer(c, ast::StorageClass::kNone, ty, rhs)) {
return nullptr;
}
if (!ApplyStorageClassUsageToType(ast::StorageClass::kNone, const_cast<sem::Type*>(ty),
c->source)) {
AddNote("while instantiating 'const' " + builder_->Symbols().NameFor(c->symbol), c->source);
return nullptr;
}
auto* sem = is_global ? static_cast<sem::Variable*>(builder_->create<sem::GlobalVariable>(
c, ty, sem::EvaluationStage::kConstant, ast::StorageClass::kNone,
ast::Access::kUndefined, value, sem::BindingPoint{}))
: static_cast<sem::Variable*>(builder_->create<sem::LocalVariable>(
c, ty, sem::EvaluationStage::kConstant, ast::StorageClass::kNone,
ast::Access::kUndefined, current_statement_, value));
sem->SetConstructor(rhs);
builder_->Sem().Add(c, sem);
return sem;
}
sem::Variable* Resolver::Var(const ast::Var* var, bool is_global) {
const sem::Type* storage_ty = nullptr;
// If the variable has a declared type, resolve it.
if (auto* ty = var->type) {
storage_ty = Type(ty);
if (!storage_ty) {
return nullptr;
}
}
const sem::Expression* rhs = nullptr;
// Does the variable have a constructor?
if (var->constructor) {
rhs = Materialize(Expression(var->constructor), storage_ty);
if (!rhs) {
return nullptr;
}
// If the variable has no declared type, infer it from the RHS
if (!storage_ty) {
storage_ty = rhs->Type()->UnwrapRef(); // Implicit load of RHS
}
}
if (!storage_ty) {
AddError("var declaration requires a type or initializer", var->source);
return nullptr;
}
auto storage_class = var->declared_storage_class;
if (storage_class == ast::StorageClass::kNone) {
// No declared storage class. Infer from usage / type.
if (!is_global) {
storage_class = ast::StorageClass::kFunction;
} else if (storage_ty->UnwrapRef()->is_handle()) {
// 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 storage class attribute. The
// storage class will always be handle.
storage_class = ast::StorageClass::kHandle;
}
}
if (!is_global && storage_class != ast::StorageClass::kFunction &&
validator_.IsValidationEnabled(var->attributes,
ast::DisabledValidation::kIgnoreStorageClass)) {
AddError("function-scope 'var' declaration must use 'function' storage class", var->source);
return nullptr;
}
auto access = var->declared_access;
if (access == ast::Access::kUndefined) {
access = DefaultAccessForStorageClass(storage_class);
}
if (rhs && !validator_.VariableInitializer(var, storage_class, storage_ty, rhs)) {
return nullptr;
}
auto* var_ty = builder_->create<sem::Reference>(storage_ty, storage_class, access);
if (!ApplyStorageClassUsageToType(storage_class, var_ty, var->source)) {
AddNote("while instantiating 'var' " + builder_->Symbols().NameFor(var->symbol),
var->source);
return nullptr;
}
sem::Variable* sem = nullptr;
if (is_global) {
sem::BindingPoint binding_point;
if (auto bp = var->BindingPoint()) {
binding_point = {bp.group->value, bp.binding->value};
}
sem = builder_->create<sem::GlobalVariable>(var, var_ty, sem::EvaluationStage::kRuntime,
storage_class, access,
/* constant_value */ nullptr, binding_point);
} else {
sem = builder_->create<sem::LocalVariable>(var, var_ty, sem::EvaluationStage::kRuntime,
storage_class, access, current_statement_,
/* constant_value */ nullptr);
}
sem->SetConstructor(rhs);
builder_->Sem().Add(var, sem);
return sem;
}
sem::Parameter* Resolver::Parameter(const ast::Parameter* param, uint32_t index) {
auto add_note = [&] {
AddNote("while instantiating parameter " + builder_->Symbols().NameFor(param->symbol),
param->source);
};
for (auto* attr : param->attributes) {
Mark(attr);
}
if (!validator_.NoDuplicateAttributes(param->attributes)) {
return nullptr;
}
sem::Type* ty = Type(param->type);
if (!ty) {
return nullptr;
}
if (!ApplyStorageClassUsageToType(ast::StorageClass::kNone, ty, param->source)) {
add_note();
return nullptr;
}
if (auto* ptr = ty->As<sem::Pointer>()) {
// For MSL, we push module-scope variables into the entry point as pointer
// parameters, so we also need to handle their store type.
if (!ApplyStorageClassUsageToType(
ptr->StorageClass(), const_cast<sem::Type*>(ptr->StoreType()), param->source)) {
add_note();
return nullptr;
}
}
auto* sem = builder_->create<sem::Parameter>(param, index, ty, ast::StorageClass::kNone,
ast::Access::kUndefined);
builder_->Sem().Add(param, sem);
return sem;
}
ast::Access Resolver::DefaultAccessForStorageClass(ast::StorageClass storage_class) {
// https://gpuweb.github.io/gpuweb/wgsl/#storage-class
switch (storage_class) {
case ast::StorageClass::kStorage:
case ast::StorageClass::kUniform:
case ast::StorageClass::kHandle:
return ast::Access::kRead;
default:
break;
}
return ast::Access::kReadWrite;
}
void Resolver::AllocateOverridableConstantIds() {
// The next pipeline constant ID to try to allocate.
uint16_t next_constant_id = 0;
// Allocate constant IDs in global declaration order, so that they are
// deterministic.
// TODO(crbug.com/tint/1192): If a transform changes the order or removes an
// unused constant, the allocation may change on the next Resolver pass.
for (auto* decl : builder_->AST().GlobalDeclarations()) {
auto* override = decl->As<ast::Override>();
if (!override) {
continue;
}
uint16_t constant_id;
if (auto* id_attr = ast::GetAttribute<ast::IdAttribute>(override->attributes)) {
constant_id = static_cast<uint16_t>(id_attr->value);
} else {
// No ID was specified, so allocate the next available ID.
constant_id = next_constant_id;
while (constant_ids_.count(constant_id)) {
if (constant_id == UINT16_MAX) {
TINT_ICE(Resolver, builder_->Diagnostics())
<< "no more pipeline constant IDs available";
return;
}
constant_id++;
}
next_constant_id = constant_id + 1;
}
auto* sem = sem_.Get<sem::GlobalVariable>(override);
const_cast<sem::GlobalVariable*>(sem)->SetConstantId(constant_id);
}
}
void Resolver::SetShadows() {
for (auto it : dependencies_.shadows) {
Switch(
sem_.Get(it.first), //
[&](sem::LocalVariable* local) { local->SetShadows(sem_.Get(it.second)); },
[&](sem::Parameter* param) { param->SetShadows(sem_.Get(it.second)); });
}
}
sem::GlobalVariable* Resolver::GlobalVariable(const ast::Variable* v) {
auto* sem = As<sem::GlobalVariable>(Variable(v, /* is_global */ true));
if (!sem) {
return nullptr;
}
for (auto* attr : v->attributes) {
Mark(attr);
if (auto* id_attr = attr->As<ast::IdAttribute>()) {
// Track the constant IDs that are specified in the shader.
constant_ids_.emplace(id_attr->value, sem);
}
}
if (!validator_.NoDuplicateAttributes(v->attributes)) {
return nullptr;
}
if (!validator_.GlobalVariable(sem, constant_ids_, atomic_composite_info_)) {
return nullptr;
}
// TODO(bclayton): Call this at the end of resolve on all uniform and storage
// referenced structs
if (!validator_.StorageClassLayout(sem, valid_type_storage_layouts_)) {
return nullptr;
}
return sem;
}
sem::Function* Resolver::Function(const ast::Function* decl) {
uint32_t parameter_index = 0;
std::unordered_map<Symbol, Source> parameter_names;
std::vector<sem::Parameter*> parameters;
// Resolve all the parameters
for (auto* param : decl->params) {
Mark(param);
{ // Check the parameter name is unique for the function
auto emplaced = parameter_names.emplace(param->symbol, param->source);
if (!emplaced.second) {
auto name = builder_->Symbols().NameFor(param->symbol);
AddError("redefinition of parameter '" + name + "'", param->source);
AddNote("previous definition is here", emplaced.first->second);
return nullptr;
}
}
auto* p = Parameter(param, parameter_index++);
if (!p) {
return nullptr;
}
if (!validator_.Parameter(decl, p)) {
return nullptr;
}
parameters.emplace_back(p);
auto* p_ty = const_cast<sem::Type*>(p->Type());
if (auto* str = p_ty->As<sem::Struct>()) {
switch (decl->PipelineStage()) {
case ast::PipelineStage::kVertex:
str->AddUsage(sem::PipelineStageUsage::kVertexInput);
break;
case ast::PipelineStage::kFragment:
str->AddUsage(sem::PipelineStageUsage::kFragmentInput);
break;
case ast::PipelineStage::kCompute:
str->AddUsage(sem::PipelineStageUsage::kComputeInput);
break;
case ast::PipelineStage::kNone:
break;
}
}
}
// Resolve the return type
sem::Type* return_type = nullptr;
if (auto* ty = decl->return_type) {
return_type = Type(ty);
if (!return_type) {
return nullptr;
}
} else {
return_type = builder_->create<sem::Void>();
}
if (auto* str = return_type->As<sem::Struct>()) {
if (!ApplyStorageClassUsageToType(ast::StorageClass::kNone, str, decl->source)) {
AddNote(
"while instantiating return type for " + builder_->Symbols().NameFor(decl->symbol),
decl->source);
return nullptr;
}
switch (decl->PipelineStage()) {
case ast::PipelineStage::kVertex:
str->AddUsage(sem::PipelineStageUsage::kVertexOutput);
break;
case ast::PipelineStage::kFragment:
str->AddUsage(sem::PipelineStageUsage::kFragmentOutput);
break;
case ast::PipelineStage::kCompute:
str->AddUsage(sem::PipelineStageUsage::kComputeOutput);
break;
case ast::PipelineStage::kNone:
break;
}
}
auto* func = builder_->create<sem::Function>(decl, return_type, parameters);
builder_->Sem().Add(decl, func);
TINT_SCOPED_ASSIGNMENT(current_function_, func);
if (!WorkgroupSize(decl)) {
return nullptr;
}
if (decl->IsEntryPoint()) {
entry_points_.emplace_back(func);
}
if (decl->body) {
Mark(decl->body);
if (current_compound_statement_) {
TINT_ICE(Resolver, diagnostics_)
<< "Resolver::Function() called with a current compound statement";
return nullptr;
}
auto* body = StatementScope(decl->body, builder_->create<sem::FunctionBlockStatement>(func),
[&] { return Statements(decl->body->statements); });
if (!body) {
return nullptr;
}
func->Behaviors() = body->Behaviors();
if (func->Behaviors().Contains(sem::Behavior::kReturn)) {
// https://www.w3.org/TR/WGSL/#behaviors-rules
// We assign a behavior to each function: it is its body’s behavior
// (treating the body as a regular statement), with any "Return" replaced
// by "Next".
func->Behaviors().Remove(sem::Behavior::kReturn);
func->Behaviors().Add(sem::Behavior::kNext);
}
}
for (auto* attr : decl->attributes) {
Mark(attr);
}
if (!validator_.NoDuplicateAttributes(decl->attributes)) {
return nullptr;
}
for (auto* attr : decl->return_type_attributes) {
Mark(attr);
}
if (!validator_.NoDuplicateAttributes(decl->return_type_attributes)) {
return nullptr;
}
auto stage = current_function_ ? current_function_->Declaration()->PipelineStage()
: ast::PipelineStage::kNone;
if (!validator_.Function(func, stage)) {
return nullptr;
}
// If this is an entry point, mark all transitively called functions as being
// used by this entry point.
if (decl->IsEntryPoint()) {
for (auto* f : func->TransitivelyCalledFunctions()) {
const_cast<sem::Function*>(f)->AddAncestorEntryPoint(func);
}
}
return func;
}
bool Resolver::WorkgroupSize(const ast::Function* func) {
// Set work-group size defaults.
sem::WorkgroupSize ws;
for (size_t i = 0; i < 3; i++) {
ws[i].value = 1;
ws[i].overridable_const = nullptr;
}
auto* attr = ast::GetAttribute<ast::WorkgroupAttribute>(func->attributes);
if (!attr) {
return true;
}
auto values = attr->Values();
std::array<const sem::Expression*, 3> args = {};
std::array<const sem::Type*, 3> arg_tys = {};
size_t arg_count = 0;
constexpr const char* kErrBadExpr =
"workgroup_size argument must be either a literal, constant, or overridable of type "
"abstract-integer, i32 or u32";
for (size_t i = 0; i < 3; i++) {
// Each argument to this attribute can either be a literal, an identifier for a module-scope
// constants, or nullptr if not specified.
auto* value = values[i];
if (!value) {
break;
}
const auto* expr = Expression(value);
if (!expr) {
return false;
}
auto* ty = expr->Type();
if (!ty->IsAnyOf<sem::I32, sem::U32, sem::AbstractInt>()) {
AddError(kErrBadExpr, value->source);
return false;
}
args[i] = expr;
arg_tys[i] = ty;
arg_count++;
}
auto* common_ty = sem::Type::Common(arg_tys.data(), arg_count);
if (!common_ty) {
AddError("workgroup_size arguments must be of the same type, either i32 or u32",
attr->source);
return false;
}
// If all arguments are abstract-integers, then materialize to i32.
if (common_ty->Is<sem::AbstractInt>()) {
common_ty = builder_->create<sem::I32>();
}
for (size_t i = 0; i < arg_count; i++) {
auto* materialized = Materialize(args[i], common_ty);
if (!materialized) {
return false;
}
const sem::Constant* value = nullptr;
if (auto* user = args[i]->As<sem::VariableUser>()) {
// We have an variable of a module-scope constant.
auto* decl = user->Variable()->Declaration();
if (!decl->IsAnyOf<ast::Const, ast::Override>()) {
AddError(kErrBadExpr, values[i]->source);
return false;
}
// Capture the constant if it is pipeline-overridable.
if (decl->Is<ast::Override>()) {
ws[i].overridable_const = decl;
}
if (decl->constructor) {
value = sem_.Get(decl->constructor)->ConstantValue();
} else {
// No constructor means this value must be overriden by the user.
ws[i].value = 0;
continue;
}
} else if (values[i]->Is<ast::LiteralExpression>()) {
value = materialized->ConstantValue();
} else {
AddError(kErrBadExpr, values[i]->source);
return false;
}
if (!value) {
TINT_ICE(Resolver, diagnostics_)
<< "could not resolve constant workgroup_size constant value";
continue;
}
// validator_.Validate and set the default value for this dimension.
if (value->As<AInt>() < 1) {
AddError("workgroup_size argument must be at least 1", values[i]->source);
return false;
}
ws[i].value = value->As<uint32_t>();
}
current_function_->SetWorkgroupSize(std::move(ws));
return true;
}
bool Resolver::Statements(const ast::StatementList& stmts) {
sem::Behaviors behaviors{sem::Behavior::kNext};
bool reachable = true;
for (auto* stmt : stmts) {
Mark(stmt);
auto* sem = Statement(stmt);
if (!sem) {
return false;
}
// s1 s2:(B1∖{Next}) ∪ B2
sem->SetIsReachable(reachable);
if (reachable) {
behaviors = (behaviors - sem::Behavior::kNext) + sem->Behaviors();
}
reachable = reachable && sem->Behaviors().Contains(sem::Behavior::kNext);
}
current_statement_->Behaviors() = behaviors;
if (!validator_.Statements(stmts)) {
return false;
}
return true;
}
sem::Statement* Resolver::Statement(const ast::Statement* stmt) {
return Switch(
stmt,
// Compound statements. These create their own sem::CompoundStatement
// bindings.
[&](const ast::BlockStatement* b) { return BlockStatement(b); },
[&](const ast::ForLoopStatement* l) { return ForLoopStatement(l); },
[&](const ast::LoopStatement* l) { return LoopStatement(l); },
[&](const ast::WhileStatement* w) { return WhileStatement(w); },
[&](const ast::IfStatement* i) { return IfStatement(i); },
[&](const ast::SwitchStatement* s) { return SwitchStatement(s); },
// Non-Compound statements
[&](const ast::AssignmentStatement* a) { return AssignmentStatement(a); },
[&](const ast::BreakStatement* b) { return BreakStatement(b); },
[&](const ast::CallStatement* c) { return CallStatement(c); },
[&](const ast::CompoundAssignmentStatement* c) { return CompoundAssignmentStatement(c); },
[&](const ast::ContinueStatement* c) { return ContinueStatement(c); },
[&](const ast::DiscardStatement* d) { return DiscardStatement(d); },
[&](const ast::FallthroughStatement* f) { return FallthroughStatement(f); },
[&](const ast::IncrementDecrementStatement* i) { return IncrementDecrementStatement(i); },
[&](const ast::ReturnStatement* r) { return ReturnStatement(r); },
[&](const ast::VariableDeclStatement* v) { return VariableDeclStatement(v); },
// Error cases
[&](const ast::CaseStatement*) {
AddError("case statement can only be used inside a switch statement", stmt->source);
return nullptr;
},
[&](Default) {
AddError("unknown statement type: " + std::string(stmt->TypeInfo().name), stmt->source);
return nullptr;
});
}
sem::CaseStatement* Resolver::CaseStatement(const ast::CaseStatement* stmt) {
auto* sem =
builder_->create<sem::CaseStatement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
sem->Selectors().reserve(stmt->selectors.size());
for (auto* sel : stmt->selectors) {
auto* expr = Expression(sel);
if (!expr) {
return false;
}
sem->Selectors().emplace_back(expr);
}
Mark(stmt->body);
auto* body = BlockStatement(stmt->body);
if (!body) {
return false;
}
sem->SetBlock(body);
sem->Behaviors() = body->Behaviors();
return true;
});
}
sem::IfStatement* Resolver::IfStatement(const ast::IfStatement* stmt) {
auto* sem =
builder_->create<sem::IfStatement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
auto* cond = Expression(stmt->condition);
if (!cond) {
return false;
}
sem->SetCondition(cond);
sem->Behaviors() = cond->Behaviors();
sem->Behaviors().Remove(sem::Behavior::kNext);
Mark(stmt->body);
auto* body = builder_->create<sem::BlockStatement>(stmt->body, current_compound_statement_,
current_function_);
if (!StatementScope(stmt->body, body, [&] { return Statements(stmt->body->statements); })) {
return false;
}
sem->Behaviors().Add(body->Behaviors());
if (stmt->else_statement) {
Mark(stmt->else_statement);
auto* else_sem = Statement(stmt->else_statement);
if (!else_sem) {
return false;
}
sem->Behaviors().Add(else_sem->Behaviors());
} else {
// https://www.w3.org/TR/WGSL/#behaviors-rules
// if statements without an else branch are treated as if they had an
// empty else branch (which adds Next to their behavior)
sem->Behaviors().Add(sem::Behavior::kNext);
}
return validator_.IfStatement(sem);
});
}
sem::BlockStatement* Resolver::BlockStatement(const ast::BlockStatement* stmt) {
auto* sem = builder_->create<sem::BlockStatement>(
stmt->As<ast::BlockStatement>(), current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] { return Statements(stmt->statements); });
}
sem::LoopStatement* Resolver::LoopStatement(const ast::LoopStatement* stmt) {
auto* sem =
builder_->create<sem::LoopStatement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
Mark(stmt->body);
auto* body = builder_->create<sem::LoopBlockStatement>(
stmt->body, current_compound_statement_, current_function_);
return StatementScope(stmt->body, body, [&] {
if (!Statements(stmt->body->statements)) {
return false;
}
auto& behaviors = sem->Behaviors();
behaviors = body->Behaviors();
if (stmt->continuing) {
Mark(stmt->continuing);
auto* continuing = StatementScope(
stmt->continuing,
builder_->create<sem::LoopContinuingBlockStatement>(
stmt->continuing, current_compound_statement_, current_function_),
[&] { return Statements(stmt->continuing->statements); });
if (!continuing) {
return false;
}
behaviors.Add(continuing->Behaviors());
}
if (behaviors.Contains(sem::Behavior::kBreak)) { // Does the loop exit?
behaviors.Add(sem::Behavior::kNext);
} else {
behaviors.Remove(sem::Behavior::kNext);
}
behaviors.Remove(sem::Behavior::kBreak, sem::Behavior::kContinue);
return validator_.LoopStatement(sem);
});
});
}
sem::ForLoopStatement* Resolver::ForLoopStatement(const ast::ForLoopStatement* stmt) {
auto* sem = builder_->create<sem::ForLoopStatement>(stmt, current_compound_statement_,
current_function_);
return StatementScope(stmt, sem, [&] {
auto& behaviors = sem->Behaviors();
if (auto* initializer = stmt->initializer) {
Mark(initializer);
auto* init = Statement(initializer);
if (!init) {
return false;
}
behaviors.Add(init->Behaviors());
}
if (auto* cond_expr = stmt->condition) {
auto* cond = Expression(cond_expr);
if (!cond) {
return false;
}
sem->SetCondition(cond);
behaviors.Add(cond->Behaviors());
}
if (auto* continuing = stmt->continuing) {
Mark(continuing);
auto* cont = Statement(continuing);
if (!cont) {
return false;
}
behaviors.Add(cont->Behaviors());
}
Mark(stmt->body);
auto* body = builder_->create<sem::LoopBlockStatement>(
stmt->body, current_compound_statement_, current_function_);
if (!StatementScope(stmt->body, body, [&] { return Statements(stmt->body->statements); })) {
return false;
}
behaviors.Add(body->Behaviors());
if (stmt->condition || behaviors.Contains(sem::Behavior::kBreak)) { // Does the loop exit?
behaviors.Add(sem::Behavior::kNext);
} else {
behaviors.Remove(sem::Behavior::kNext);
}
behaviors.Remove(sem::Behavior::kBreak, sem::Behavior::kContinue);
return validator_.ForLoopStatement(sem);
});
}
sem::WhileStatement* Resolver::WhileStatement(const ast::WhileStatement* stmt) {
auto* sem =
builder_->create<sem::WhileStatement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
auto& behaviors = sem->Behaviors();
auto* cond = Expression(stmt->condition);
if (!cond) {
return false;
}
sem->SetCondition(cond);
behaviors.Add(cond->Behaviors());
Mark(stmt->body);
auto* body = builder_->create<sem::LoopBlockStatement>(
stmt->body, current_compound_statement_, current_function_);
if (!StatementScope(stmt->body, body, [&] { return Statements(stmt->body->statements); })) {
return false;
}
behaviors.Add(body->Behaviors());
// Always consider the while as having a 'next' behaviour because it has
// a condition. We don't check if the condition will terminate but it isn't
// valid to have an infinite loop in a WGSL program, so a non-terminating
// condition is already an invalid program.
behaviors.Add(sem::Behavior::kNext);
behaviors.Remove(sem::Behavior::kBreak, sem::Behavior::kContinue);
return validator_.WhileStatement(sem);
});
}
sem::Expression* Resolver::Expression(const ast::Expression* root) {
std::vector<const ast::Expression*> sorted;
constexpr size_t kMaxExpressionDepth = 512U;
bool failed = false;
if (!ast::TraverseExpressions<ast::TraverseOrder::RightToLeft>(
root, diagnostics_, [&](const ast::Expression* expr, size_t depth) {
if (depth > kMaxExpressionDepth) {
AddError(
"reached max expression depth of " + std::to_string(kMaxExpressionDepth),
expr->source);
failed = true;
return ast::TraverseAction::Stop;
}
if (!Mark(expr)) {
failed = true;
return ast::TraverseAction::Stop;
}
sorted.emplace_back(expr);
return ast::TraverseAction::Descend;
})) {
return nullptr;
}
if (failed) {
return nullptr;
}
for (auto* expr : utils::Reverse(sorted)) {
auto* sem_expr = Switch(
expr,
[&](const ast::IndexAccessorExpression* array) -> sem::Expression* {
return IndexAccessor(array);
},
[&](const ast::BinaryExpression* bin_op) -> sem::Expression* { return Binary(bin_op); },
[&](const ast::BitcastExpression* bitcast) -> sem::Expression* {
return Bitcast(bitcast);
},
[&](const ast::CallExpression* call) -> sem::Expression* { return Call(call); },
[&](const ast::IdentifierExpression* ident) -> sem::Expression* {
return Identifier(ident);
},
[&](const ast::LiteralExpression* literal) -> sem::Expression* {
return Literal(literal);
},
[&](const ast::MemberAccessorExpression* member) -> sem::Expression* {
return MemberAccessor(member);
},
[&](const ast::UnaryOpExpression* unary) -> sem::Expression* { return UnaryOp(unary); },
[&](const ast::PhonyExpression*) -> sem::Expression* {
return builder_->create<sem::Expression>(expr, builder_->create<sem::Void>(),
sem::EvaluationStage::kRuntime,
current_statement_,
/* constant_value */ nullptr,
/* has_side_effects */ false);
},
[&](Default) {
TINT_ICE(Resolver, diagnostics_)
<< "unhandled expression type: " << expr->TypeInfo().name;
return nullptr;
});
if (!sem_expr) {
return nullptr;
}
builder_->Sem().Add(expr, sem_expr);
if (expr == root) {
return sem_expr;
}
}
TINT_ICE(Resolver, diagnostics_) << "Expression() did not find root node";
return nullptr;
}
const sem::Expression* Resolver::Materialize(const sem::Expression* expr,
const sem::Type* target_type /* = nullptr */) {
if (!expr) {
return nullptr; // Allow for Materialize(Expression(blah))
}
// Helper for actually creating the the materialize node, performing the constant cast, updating
// the ast -> sem binding, and performing validation.
auto materialize = [&](const sem::Type* target_ty) -> sem::Materialize* {
auto* src_ty = expr->Type();
auto* decl = expr->Declaration();
if (!validator_.Materialize(target_ty, src_ty, decl->source)) {
return nullptr;
}
auto expr_val = expr->ConstantValue();
if (!expr_val) {
TINT_ICE(Resolver, builder_->Diagnostics())
<< decl->source << "Materialize(" << decl->TypeInfo().name
<< ") called on expression with no constant value";
return nullptr;
}
auto materialized_val = const_eval_.Convert(target_ty, expr_val, decl->source);
if (!materialized_val) {
// ConvertValue() has already failed and raised an diagnostic error.
return nullptr;
}
if (!materialized_val.Get()) {
TINT_ICE(Resolver, builder_->Diagnostics())
<< decl->source << "ConvertValue(" << builder_->FriendlyName(expr_val->Type())
<< " -> " << builder_->FriendlyName(target_ty) << ") returned invalid value";
return nullptr;
}
auto* m =
builder_->create<sem::Materialize>(expr, current_statement_, materialized_val.Get());
m->Behaviors() = expr->Behaviors();
builder_->Sem().Replace(decl, m);
return m;
};
// Helpers for constructing semantic types
auto i32 = [&] { return builder_->create<sem::I32>(); };
auto f32 = [&] { return builder_->create<sem::F32>(); };
auto i32v = [&](uint32_t width) { return builder_->create<sem::Vector>(i32(), width); };
auto f32v = [&](uint32_t width) { return builder_->create<sem::Vector>(f32(), width); };
auto f32m = [&](uint32_t columns, uint32_t rows) {
return builder_->create<sem::Matrix>(f32v(rows), columns);
};
// Type dispatch based on the expression type
return Switch<sem::Expression*>(
expr->Type(), //
[&](const sem::AbstractInt*) { return materialize(target_type ? target_type : i32()); },
[&](const sem::AbstractFloat*) { return materialize(target_type ? target_type : f32()); },
[&](const sem::Vector* v) {
return Switch(
v->type(), //
[&](const sem::AbstractInt*) {
return materialize(target_type ? target_type : i32v(v->Width()));
},
[&](const sem::AbstractFloat*) {
return materialize(target_type ? target_type : f32v(v->Width()));
},
[&](Default) { return expr; });
},
[&](const sem::Matrix* m) {
return Switch(
m->type(), //
[&](const sem::AbstractFloat*) {
return materialize(target_type ? target_type : f32m(m->columns(), m->rows()));
},
[&](Default) { return expr; });
},
[&](Default) { return expr; });
}
bool Resolver::MaterializeArguments(std::vector<const sem::Expression*>& args,
const sem::CallTarget* target) {
for (size_t i = 0, n = std::min(args.size(), target->Parameters().size()); i < n; i++) {
const auto* param_ty = target->Parameters()[i]->Type();
if (ShouldMaterializeArgument(param_ty)) {
auto* materialized = Materialize(args[i], param_ty);
if (!materialized) {
return false;
}
args[i] = materialized;
}
}
return true;
}
bool Resolver::ShouldMaterializeArgument(const sem::Type* parameter_ty) const {
const auto* param_el_ty = sem::Type::ElementOf(parameter_ty);
return param_el_ty && !param_el_ty->Is<sem::AbstractNumeric>();
}
sem::Expression* Resolver::IndexAccessor(const ast::IndexAccessorExpression* expr) {
auto* idx = Materialize(sem_.Get(expr->index));
if (!idx) {
return nullptr;
}
auto* obj = sem_.Get(expr->object);
auto* obj_raw_ty = obj->Type();
auto* obj_ty = obj_raw_ty->UnwrapRef();
auto* ty = Switch(
obj_ty, //
[&](const sem::Array* arr) { return arr->ElemType(); },
[&](const sem::Vector* vec) { return vec->type(); },
[&](const sem::Matrix* mat) {
return builder_->create<sem::Vector>(mat->type(), mat->rows());
},
[&](Default) {
AddError("cannot index type '" + sem_.TypeNameOf(obj_ty) + "'", expr->source);
return nullptr;
});
if (ty == nullptr) {
return nullptr;
}
auto* idx_ty = idx->Type()->UnwrapRef();
if (!idx_ty->IsAnyOf<sem::I32, sem::U32>()) {
AddError("index must be of type 'i32' or 'u32', found: '" + sem_.TypeNameOf(idx_ty) + "'",
idx->Declaration()->source);
return nullptr;
}
// If we're extracting from a reference, we return a reference.
if (auto* ref = obj_raw_ty->As<sem::Reference>()) {
ty = builder_->create<sem::Reference>(ty, ref->StorageClass(), ref->Access());
}
auto stage = sem::EarliestStage(obj->Stage(), idx->Stage());
auto val = const_eval_.Index(obj, idx);
bool has_side_effects = idx->HasSideEffects() || obj->HasSideEffects();
auto* sem = builder_->create<sem::IndexAccessorExpression>(
expr, ty, stage, obj, idx, current_statement_, std::move(val), has_side_effects,
obj->SourceVariable());
sem->Behaviors() = idx->Behaviors() + obj->Behaviors();
return sem;
}
sem::Expression* Resolver::Bitcast(const ast::BitcastExpression* expr) {
auto* inner = Materialize(sem_.Get(expr->expr));
if (!inner) {
return nullptr;
}
auto* ty = Type(expr->type);
if (!ty) {
return nullptr;
}
auto val = const_eval_.Bitcast(ty, inner);
auto stage = sem::EvaluationStage::kRuntime; // TODO(crbug.com/tint/1581)
auto* sem = builder_->create<sem::Expression>(expr, ty, stage, current_statement_,
std::move(val), inner->HasSideEffects());
sem->Behaviors() = inner->Behaviors();
if (!validator_.Bitcast(expr, ty)) {
return nullptr;
}
return sem;
}
sem::Call* Resolver::Call(const ast::CallExpression* expr) {
// A CallExpression can resolve to one of:
// * A function call.
// * A builtin call.
// * A type constructor.
// * A type conversion.
// Resolve all of the arguments, their types and the set of behaviors.
std::vector<const sem::Expression*> args(expr->args.size());
auto args_stage = sem::EvaluationStage::kConstant;
sem::Behaviors arg_behaviors;
for (size_t i = 0; i < expr->args.size(); i++) {
auto* arg = sem_.Get(expr->args[i]);
if (!arg) {
return nullptr;
}
args[i] = arg;
args_stage = sem::EarliestStage(args_stage, arg->Stage());
arg_behaviors.Add(arg->Behaviors());
}
arg_behaviors.Remove(sem::Behavior::kNext);
// Did any arguments have side effects?
bool has_side_effects =
std::any_of(args.begin(), args.end(), [](auto* e) { return e->HasSideEffects(); });
// ct_ctor_or_conv is a helper for building either a sem::TypeConstructor or sem::TypeConversion
// call for a CtorConvIntrinsic with an optional template argument type.
auto ct_ctor_or_conv = [&](CtorConvIntrinsic ty, const sem::Type* template_arg) -> sem::Call* {
auto arg_tys = utils::Transform(args, [](auto* arg) { return arg->Type(); });
auto ctor_or_conv = intrinsic_table_->Lookup(ty, template_arg, arg_tys, expr->source);
if (!ctor_or_conv.target) {
return nullptr;
}
if (!MaterializeArguments(args, ctor_or_conv.target)) {
return nullptr;
}
const sem::Constant* value = nullptr;
auto stage = sem::EarliestStage(ctor_or_conv.target->Stage(), args_stage);
if (stage == sem::EvaluationStage::kConstant) {
value = (const_eval_.*ctor_or_conv.const_eval_fn)(ctor_or_conv.target->ReturnType(),
args.data(), args.size());
}
return builder_->create<sem::Call>(expr, ctor_or_conv.target, stage, std::move(args),
current_statement_, value, has_side_effects);
};
// arr_or_str_ctor is a helper for building a sem::TypeConstructor for an array or structure
// constructor call target.
auto arr_or_str_ctor = [&](const sem::Type* ty,
const sem::CallTarget* call_target) -> sem::Call* {
if (!MaterializeArguments(args, call_target)) {
return nullptr;
}
auto stage = args_stage; // The evaluation stage of the call
const sem::Constant* value = nullptr; // The constant value for the call
if (stage == sem::EvaluationStage::kConstant) {
value = const_eval_.ArrayOrStructCtor(ty, args);
if (!value) {
// Constant evaluation failed.
// Can happen for expressions that will fail validation (later).
// Use the kRuntime EvaluationStage, as kConstant will trigger an assertion in the
// sem::Expression constructor, which checks that kConstant is paired with a
// constant value.
stage = sem::EvaluationStage::kRuntime;
}
}
return builder_->create<sem::Call>(expr, call_target, stage, std::move(args),
current_statement_, value, has_side_effects);
};
// ty_ctor_or_conv is a helper for building either a sem::TypeConstructor or sem::TypeConversion
// call for the given semantic type.
auto ty_ctor_or_conv = [&](const sem::Type* ty) {
return Switch(
ty, //
[&](const sem::Vector* v) {
return ct_ctor_or_conv(VectorCtorConvIntrinsic(v->Width()), v->type());
},
[&](const sem::Matrix* m) {
return ct_ctor_or_conv(MatrixCtorConvIntrinsic(m->columns(), m->rows()), m->type());
},
[&](const sem::I32*) { return ct_ctor_or_conv(CtorConvIntrinsic::kI32, nullptr); },
[&](const sem::U32*) { return ct_ctor_or_conv(CtorConvIntrinsic::kU32, nullptr); },
[&](const sem::F16*) { return ct_ctor_or_conv(CtorConvIntrinsic::kF16, nullptr); },
[&](const sem::F32*) { return ct_ctor_or_conv(CtorConvIntrinsic::kF32, nullptr); },
[&](const sem::Bool*) { return ct_ctor_or_conv(CtorConvIntrinsic::kBool, nullptr); },
[&](const sem::Array* arr) -> sem::Call* {
auto* call_target = utils::GetOrCreate(
array_ctors_, ArrayConstructorSig{{arr, args.size(), args_stage}},
[&]() -> sem::TypeConstructor* {
sem::ParameterList params(args.size());
for (size_t i = 0; i < args.size(); i++) {
params[i] = builder_->create<sem::Parameter>(
nullptr, // declaration
static_cast<uint32_t>(i), // index
arr->ElemType(), // type
ast::StorageClass::kNone, // storage_class
ast::Access::kUndefined); // access
}
return builder_->create<sem::TypeConstructor>(arr, std::move(params),
args_stage);
});
return arr_or_str_ctor(arr, call_target);
},
[&](const sem::Struct* str) -> sem::Call* {
auto* call_target = utils::GetOrCreate(
struct_ctors_, StructConstructorSig{{str, args.size(), args_stage}},
[&]() -> sem::TypeConstructor* {
sem::ParameterList params(std::min(args.size(), str->Members().size()));
for (size_t i = 0, n = params.size(); i < n; i++) {
params[i] = builder_->create<sem::Parameter>(
nullptr, // declaration
static_cast<uint32_t>(i), // index
str->Members()[i]->Type(), // type
ast::StorageClass::kNone, // storage_class
ast::Access::kUndefined); // access
}
return builder_->create<sem::TypeConstructor>(str, std::move(params),
args_stage);
});
return arr_or_str_ctor(str, call_target);
},
[&](Default) {
AddError("type is not constructible", expr->source);
return nullptr;
});
};
// ast::CallExpression has a target which is either an ast::Type or an ast::IdentifierExpression
sem::Call* call = nullptr;
if (expr->target.type) {
// ast::CallExpression has an ast::Type as the target.
// This call is either a type constructor or type conversion.
call = Switch(
expr->target.type,
[&](const ast::Vector* v) -> sem::Call* {
Mark(v);
// vector element type must be inferred if it was not specified.
sem::Type* template_arg = nullptr;
if (v->type) {
template_arg = Type(v->type);
if (!template_arg) {
return nullptr;
}
}
if (auto* c = ct_ctor_or_conv(VectorCtorConvIntrinsic(v->width), template_arg)) {
builder_->Sem().Add(expr->target.type, c->Target()->ReturnType());
return c;
}
return nullptr;
},
[&](const ast::Matrix* m) -> sem::Call* {
Mark(m);
// matrix element type must be inferred if it was not specified.
sem::Type* template_arg = nullptr;
if (m->type) {
template_arg = Type(m->type);
if (!template_arg) {
return nullptr;
}
}
if (auto* c = ct_ctor_or_conv(MatrixCtorConvIntrinsic(m->columns, m->rows),
template_arg)) {
builder_->Sem().Add(expr->target.type, c->Target()->ReturnType());
return c;
}
return nullptr;
},
[&](const ast::Type* ast) -> sem::Call* {
// Handler for AST types that do not have an optional element type.
if (auto* ty = Type(ast)) {
return ty_ctor_or_conv(ty);
}
return nullptr;
},
[&](Default) {
TINT_ICE(Resolver, diagnostics_)
<< expr->source << " unhandled CallExpression target:\n"
<< "type: "
<< (expr->target.type ? expr->target.type->TypeInfo().name : "<null>");
return nullptr;
});
} else {
// ast::CallExpression has an ast::IdentifierExpression as the target.
// This call is either a function call, builtin call, type constructor or type conversion.
auto* ident = expr->target.name;
Mark(ident);
auto* resolved = sem_.ResolvedSymbol(ident);
call = Switch<sem::Call*>(
resolved, //
[&](sem::Type* ty) {
// A type constructor or conversions.
// Note: Unlike the code path where we're resolving the call target from an
// ast::Type, all types must already have the element type explicitly specified, so
// there's no need to infer element types.
return ty_ctor_or_conv(ty);
},
[&](sem::Function* func) {
return FunctionCall(expr, func, std::move(args), arg_behaviors);
},
[&](sem::Variable* var) {
auto name = builder_->Symbols().NameFor(var->Declaration()->symbol);
AddError("cannot call variable '" + name + "'", ident->source);
AddNote("'" + name + "' declared here", var->Declaration()->source);
return nullptr;
},
[&](Default) -> sem::Call* {
auto name = builder_->Symbols().NameFor(ident->symbol);
auto builtin_type = sem::ParseBuiltinType(name);
if (builtin_type != sem::BuiltinType::kNone) {
return BuiltinCall(expr, builtin_type, std::move(args));
}
TINT_ICE(Resolver, diagnostics_)
<< expr->source << " unhandled CallExpression target:\n"
<< "resolved: " << (resolved ? resolved->TypeInfo().name : "<null>") << "\n"
<< "name: " << builder_->Symbols().NameFor(ident->symbol);
return nullptr;
});
}
if (!call) {
return nullptr;
}
return validator_.Call(call, current_statement_) ? call : nullptr;
}
sem::Call* Resolver::BuiltinCall(const ast::CallExpression* expr,
sem::BuiltinType builtin_type,
std::vector<const sem::Expression*> args) {
IntrinsicTable::Builtin builtin;
{
auto arg_tys = utils::Transform(args, [](auto* arg) { return arg->Type(); });
builtin = intrinsic_table_->Lookup(builtin_type, arg_tys, expr->source);
if (!builtin.sem) {
return nullptr;
}
}
if (!MaterializeArguments(args, builtin.sem)) {
return nullptr;
}
if (builtin.sem->IsDeprecated()) {
AddWarning("use of deprecated builtin", expr->source);
}
auto stage = builtin.sem->Stage();
if (stage == sem::EvaluationStage::kConstant) { // <-- Optimization
// If the builtin is not annotated with @const, then it can only be evaluated
// at runtime, in which case there's no point checking the evaluation stage of the
// arguments.
// The builtin is @const annotated. Check all arguments are also constant.
for (auto* arg : args) {
stage = sem::EarliestStage(stage, arg->Stage());
}
}
// If the builtin is @const, and all arguments have constant values, evaluate the builtin now.
const sem::Constant* value = nullptr;
if (stage == sem::EvaluationStage::kConstant) {
value = (const_eval_.*builtin.const_eval_fn)(builtin.sem->ReturnType(), args.data(),
args.size());
}
bool has_side_effects =
builtin.sem->HasSideEffects() ||
std::any_of(args.begin(), args.end(), [](auto* e) { return e->HasSideEffects(); });
auto* call = builder_->create<sem::Call>(expr, builtin.sem, stage, std::move(args),
current_statement_, value, has_side_effects);
if (current_function_) {
current_function_->AddDirectlyCalledBuiltin(builtin.sem);
current_function_->AddDirectCall(call);
}
if (!validator_.RequiredExtensionForBuiltinFunction(call, enabled_extensions_)) {
return nullptr;
}
if (IsTextureBuiltin(builtin_type)) {
if (!validator_.TextureBuiltinFunction(call)) {
return nullptr;
}
CollectTextureSamplerPairs(builtin.sem, call->Arguments());
}
if (!validator_.BuiltinCall(call)) {
return nullptr;
}
return call;
}
void Resolver::CollectTextureSamplerPairs(const sem::Builtin* builtin,
const std::vector<const sem::Expression*>& args) const {
// Collect a texture/sampler pair for this builtin.
const auto& signature = builtin->Signature();
int texture_index = signature.IndexOf(sem::ParameterUsage::kTexture);
if (texture_index == -1) {
TINT_ICE(Resolver, diagnostics_) << "texture builtin without texture parameter";
}
auto* texture = args[static_cast<size_t>(texture_index)]->As<sem::VariableUser>()->Variable();
if (!texture->Type()->UnwrapRef()->Is<sem::StorageTexture>()) {
int sampler_index = signature.IndexOf(sem::ParameterUsage::kSampler);
const sem::Variable* sampler =
sampler_index != -1
? args[static_cast<size_t>(sampler_index)]->As<sem::VariableUser>()->Variable()
: nullptr;
current_function_->AddTextureSamplerPair(texture, sampler);
}
}
sem::Call* Resolver::FunctionCall(const ast::CallExpression* expr,
sem::Function* target,
std::vector<const sem::Expression*> args,
sem::Behaviors arg_behaviors) {
auto sym = expr->target.name->symbol;
auto name = builder_->Symbols().NameFor(sym);
if (!MaterializeArguments(args, target)) {
return nullptr;
}
// TODO(crbug.com/tint/1420): For now, assume all function calls have side
// effects.
bool has_side_effects = true;
auto* call = builder_->create<sem::Call>(expr, target, sem::EvaluationStage::kRuntime,
std::move(args), current_statement_,
/* constant_value */ nullptr, has_side_effects);
target->AddCallSite(call);
call->Behaviors() = arg_behaviors + target->Behaviors();
if (!validator_.FunctionCall(call, current_statement_)) {
return nullptr;
}
if (current_function_) {
// Note: Requires called functions to be resolved first.
// This is currently guaranteed as functions must be declared before
// use.
current_function_->AddTransitivelyCalledFunction(target);
current_function_->AddDirectCall(call);
for (auto* transitive_call : target->TransitivelyCalledFunctions()) {
current_function_->AddTransitivelyCalledFunction(transitive_call);
}
// We inherit any referenced variables from the callee.
for (auto* var : target->TransitivelyReferencedGlobals()) {
current_function_->AddTransitivelyReferencedGlobal(var);
}
// Note: Validation *must* be performed before calling this method.
CollectTextureSamplerPairs(target, call->Arguments());
}
return call;
}
void Resolver::CollectTextureSamplerPairs(sem::Function* func,
const std::vector<const sem::Expression*>& args) const {
// Map all texture/sampler pairs from the target function to the
// current function. These can only be global or parameter
// variables. Resolve any parameter variables to the corresponding
// argument passed to the current function. Leave global variables
// as-is. Then add the mapped pair to the current function's list of
// texture/sampler pairs.
for (sem::VariablePair pair : func->TextureSamplerPairs()) {
const sem::Variable* texture = pair.first;
const sem::Variable* sampler = pair.second;
if (auto* param = texture->As<sem::Parameter>()) {
texture = args[param->Index()]->As<sem::VariableUser>()->Variable();
}
if (sampler) {
if (auto* param = sampler->As<sem::Parameter>()) {
sampler = args[param->Index()]->As<sem::VariableUser>()->Variable();
}
}
current_function_->AddTextureSamplerPair(texture, sampler);
}
}
sem::Expression* Resolver::Literal(const ast::LiteralExpression* literal) {
auto* ty = Switch(
literal,
[&](const ast::IntLiteralExpression* i) -> sem::Type* {
switch (i->suffix) {
case ast::IntLiteralExpression::Suffix::kNone:
return builder_->create<sem::AbstractInt>();
case ast::IntLiteralExpression::Suffix::kI:
return builder_->create<sem::I32>();
case ast::IntLiteralExpression::Suffix::kU:
return builder_->create<sem::U32>();
}
return nullptr;
},
[&](const ast::FloatLiteralExpression* f) -> sem::Type* {
switch (f->suffix) {
case ast::FloatLiteralExpression::Suffix::kNone:
return builder_->create<sem::AbstractFloat>();
case ast::FloatLiteralExpression::Suffix::kF:
return builder_->create<sem::F32>();
case ast::FloatLiteralExpression::Suffix::kH:
return builder_->create<sem::F16>();
}
return nullptr;
},
[&](const ast::BoolLiteralExpression*) { return builder_->create<sem::Bool>(); },
[&](Default) { return nullptr; });
if (ty == nullptr) {
TINT_UNREACHABLE(Resolver, builder_->Diagnostics())
<< "Unhandled literal type: " << literal->TypeInfo().name;
return nullptr;
}
if ((ty->Is<sem::F16>()) && (!enabled_extensions_.contains(tint::ast::Extension::kF16))) {
AddError("f16 literal used without 'f16' extension enabled", literal->source);
return nullptr;
}
auto val = const_eval_.Literal(ty, literal);
return builder_->create<sem::Expression>(literal, ty, sem::EvaluationStage::kConstant,
current_statement_, std::move(val),
/* has_side_effects */ false);
}
sem::Expression* Resolver::Identifier(const ast::IdentifierExpression* expr) {
auto symbol = expr->symbol;
auto* resolved = sem_.ResolvedSymbol(expr);
if (auto* variable = As<sem::Variable>(resolved)) {
auto* user = builder_->create<sem::VariableUser>(expr, current_statement_, variable);
if (current_statement_) {
// If identifier is part of a loop continuing block, make sure it
// doesn't refer to a variable that is bypassed by a continue statement
// in the loop's body block.
if (auto* continuing_block =
current_statement_->FindFirstParent<sem::LoopContinuingBlockStatement>()) {
auto* loop_block = continuing_block->FindFirstParent<sem::LoopBlockStatement>();
if (loop_block->FirstContinue()) {
auto& decls = loop_block->Decls();
// If our identifier is in loop_block->decls, make sure its index is
// less than first_continue
auto iter = std::find_if(decls.begin(), decls.end(),
[&symbol](auto* v) { return v->symbol == symbol; });
if (iter != decls.end()) {
auto var_decl_index =
static_cast<size_t>(std::distance(decls.begin(), iter));
if (var_decl_index >= loop_block->NumDeclsAtFirstContinue()) {
AddError("continue statement bypasses declaration of '" +
builder_->Symbols().NameFor(symbol) + "'",
loop_block->FirstContinue()->source);
AddNote("identifier '" + builder_->Symbols().NameFor(symbol) +
"' declared here",
(*iter)->source);
AddNote("identifier '" + builder_->Symbols().NameFor(symbol) +
"' referenced in continuing block here",
expr->source);
return nullptr;
}
}
}
}
}
if (current_function_) {
if (auto* global = variable->As<sem::GlobalVariable>()) {
current_function_->AddDirectlyReferencedGlobal(global);
}
} else if (variable->Declaration()->Is<ast::Var>()) {
// Use of a module-scope 'var' outside of a function.
// Note: The spec is currently vague around the rules here. See
// https://github.com/gpuweb/gpuweb/issues/3081. Remove this comment when resolved.
std::string desc = "var '" + builder_->Symbols().NameFor(symbol) + "' ";
AddError(desc + "cannot not be referenced at module-scope", expr->source);
AddNote(desc + "declared here", variable->Declaration()->source);
return nullptr;
}
variable->AddUser(user);
return user;
}
if (Is<sem::Function>(resolved)) {
AddError("missing '(' for function call", expr->source.End());
return nullptr;
}
if (IsBuiltin(symbol)) {
AddError("missing '(' for builtin call", expr->source.End());
return nullptr;
}
if (resolved->Is<sem::Type>()) {
AddError("missing '(' for type constructor or cast", expr->source.End());
return nullptr;
}
TINT_ICE(Resolver, diagnostics_)
<< expr->source << " unresolved identifier:\n"
<< "resolved: " << (resolved ? resolved->TypeInfo().name : "<null>") << "\n"
<< "name: " << builder_->Symbols().NameFor(symbol);
return nullptr;
}
sem::Expression* Resolver::MemberAccessor(const ast::MemberAccessorExpression* expr) {
auto* structure = sem_.TypeOf(expr->structure);
auto* storage_ty = structure->UnwrapRef();
auto* object = sem_.Get(expr->structure);
auto* source_var = object->SourceVariable();
const sem::Type* ret = nullptr;
std::vector<uint32_t> swizzle;
// Object may be a side-effecting expression (e.g. function call).
bool has_side_effects = object && object->HasSideEffects();
if (auto* str = storage_ty->As<sem::Struct>()) {
Mark(expr->member);
auto symbol = expr->member->symbol;
const sem::StructMember* member = nullptr;
for (auto* m : str->Members()) {
if (m->Name() == symbol) {
ret = m->Type();
member = m;
break;
}
}
if (ret == nullptr) {
AddError("struct member " + builder_->Symbols().NameFor(symbol) + " not found",
expr->source);
return nullptr;
}
// If we're extracting from a reference, we return a reference.
if (auto* ref = structure->As<sem::Reference>()) {
ret = builder_->create<sem::Reference>(ret, ref->StorageClass(), ref->Access());
}
auto* val = const_eval_.MemberAccess(object, member);
return builder_->create<sem::StructMemberAccess>(expr, ret, current_statement_, val, object,
member, has_side_effects, source_var);
}
if (auto* vec = storage_ty->As<sem::Vector>()) {
Mark(expr->member);
std::string s = builder_->Symbols().NameFor(expr->member->symbol);
auto size = s.size();
swizzle.reserve(s.size());
for (auto c : s) {
switch (c) {
case 'x':
case 'r':
swizzle.emplace_back(0);
break;
case 'y':
case 'g':
swizzle.emplace_back(1);
break;
case 'z':
case 'b':
swizzle.emplace_back(2);
break;
case 'w':
case 'a':
swizzle.emplace_back(3);
break;
default:
AddError("invalid vector swizzle character",
expr->member->source.Begin() + swizzle.size());
return nullptr;
}
if (swizzle.back() >= vec->Width()) {
AddError("invalid vector swizzle member", expr->member->source);
return nullptr;
}
}
if (size < 1 || size > 4) {
AddError("invalid vector swizzle size", expr->member->source);
return nullptr;
}
// All characters are valid, check if they're being mixed
auto is_rgba = [](char c) { return c == 'r' || c == 'g' || c == 'b' || c == 'a'; };
auto is_xyzw = [](char c) { return c == 'x' || c == 'y' || c == 'z' || c == 'w'; };
if (!std::all_of(s.begin(), s.end(), is_rgba) &&
!std::all_of(s.begin(), s.end(), is_xyzw)) {
AddError("invalid mixing of vector swizzle characters rgba with xyzw",
expr->member->source);
return nullptr;
}
if (size == 1) {
// A single element swizzle is just the type of the vector.
ret = vec->type();
// If we're extracting from a reference, we return a reference.
if (auto* ref = structure->As<sem::Reference>()) {
ret = builder_->create<sem::Reference>(ret, ref->StorageClass(), ref->Access());
}
} else {
// The vector will have a number of components equal to the length of
// the swizzle.
ret = builder_->create<sem::Vector>(vec->type(), static_cast<uint32_t>(size));
}
auto* val = const_eval_.Swizzle(ret, object, swizzle);
return builder_->create<sem::Swizzle>(expr, ret, current_statement_, val, object,
std::move(swizzle), has_side_effects, source_var);
}
AddError("invalid member accessor expression. Expected vector or struct, got '" +
sem_.TypeNameOf(storage_ty) + "'",
expr->structure->source);
return nullptr;
}
sem::Expression* Resolver::Binary(const ast::BinaryExpression* expr) {
const auto* lhs = sem_.Get(expr->lhs);
const auto* rhs = sem_.Get(expr->rhs);
auto* lhs_ty = lhs->Type()->UnwrapRef();
auto* rhs_ty = rhs->Type()->UnwrapRef();
auto stage = sem::EvaluationStage::kRuntime; // TODO(crbug.com/tint/1581)
auto op = intrinsic_table_->Lookup(expr->op, lhs_ty, rhs_ty, expr->source, false);
if (!op.result) {
return nullptr;
}
if (ShouldMaterializeArgument(op.lhs)) {
lhs = Materialize(lhs, op.lhs);
if (!lhs) {
return nullptr;
}
}
if (ShouldMaterializeArgument(op.rhs)) {
rhs = Materialize(rhs, op.rhs);
if (!rhs) {
return nullptr;
}
}
const sem::Constant* value = nullptr;
if (op.const_eval_fn) {
const sem::Expression* args[] = {lhs, rhs};
value = (const_eval_.*op.const_eval_fn)(op.result, args, 2u);
}
bool has_side_effects = lhs->HasSideEffects() || rhs->HasSideEffects();
auto* sem = builder_->create<sem::Expression>(expr, op.result, stage, current_statement_, value,
has_side_effects);
sem->Behaviors() = lhs->Behaviors() + rhs->Behaviors();
return sem;
}
sem::Expression* Resolver::UnaryOp(const ast::UnaryOpExpression* unary) {
const auto* expr = sem_.Get(unary->expr);
auto* expr_ty = expr->Type();
if (!expr_ty) {
return nullptr;
}
const sem::Type* ty = nullptr;
const sem::Variable* source_var = nullptr;
const sem::Constant* value = nullptr;
auto stage = sem::EvaluationStage::kRuntime;
switch (unary->op) {
case ast::UnaryOp::kAddressOf:
if (auto* ref = expr_ty->As<sem::Reference>()) {
if (ref->StoreType()->UnwrapRef()->is_handle()) {
AddError("cannot take the address of expression in handle storage class",
unary->expr->source);
return nullptr;
}
auto* array = unary->expr->As<ast::IndexAccessorExpression>();
auto* member = unary->expr->As<ast::MemberAccessorExpression>();
if ((array && sem_.TypeOf(array->object)->UnwrapRef()->Is<sem::Vector>()) ||
(member && sem_.TypeOf(member->structure)->UnwrapRef()->Is<sem::Vector>())) {
AddError("cannot take the address of a vector component", unary->expr->source);
return nullptr;
}
ty = builder_->create<sem::Pointer>(ref->StoreType(), ref->StorageClass(),
ref->Access());
source_var = expr->SourceVariable();
} else {
AddError("cannot take the address of expression", unary->expr->source);
return nullptr;
}
break;
case ast::UnaryOp::kIndirection:
if (auto* ptr = expr_ty->As<sem::Pointer>()) {
ty = builder_->create<sem::Reference>(ptr->StoreType(), ptr->StorageClass(),
ptr->Access());
source_var = expr->SourceVariable();
} else {
AddError("cannot dereference expression of type '" + sem_.TypeNameOf(expr_ty) + "'",
unary->expr->source);
return nullptr;
}
break;
default: {
auto op = intrinsic_table_->Lookup(unary->op, expr_ty, unary->source);
if (!op.result) {
return nullptr;
}
if (ShouldMaterializeArgument(op.parameter)) {
expr = Materialize(expr, op.parameter);
if (!expr) {
return nullptr;
}
}
stage = expr->Stage();
if (stage == sem::EvaluationStage::kConstant) {
if (op.const_eval_fn) {
value = (const_eval_.*op.const_eval_fn)(ty, &expr, 1u);
} else {
stage = sem::EvaluationStage::kRuntime;
}
}
ty = op.result;
break;
}
}
auto* sem = builder_->create<sem::Expression>(unary, ty, stage, current_statement_, value,
expr->HasSideEffects(), source_var);
sem->Behaviors() = expr->Behaviors();
return sem;
}
bool Resolver::Enable(const ast::Enable* enable) {
enabled_extensions_.add(enable->extension);
return true;
}
sem::Type* Resolver::TypeDecl(const ast::TypeDecl* named_type) {
sem::Type* result = nullptr;
if (auto* alias = named_type->As<ast::Alias>()) {
result = Alias(alias);
} else if (auto* str = named_type->As<ast::Struct>()) {
result = Structure(str);
} else {
TINT_UNREACHABLE(Resolver, diagnostics_) << "Unhandled TypeDecl";
}
if (!result) {
return nullptr;
}
builder_->Sem().Add(named_type, result);
return result;
}
sem::Array* Resolver::Array(const ast::Array* arr) {
auto source = arr->source;
auto* elem_type = Type(arr->type);
if (!elem_type) {
return nullptr;
}
if (!validator_.IsPlain(elem_type)) { // Check must come before GetDefaultAlignAndSize()
AddError(sem_.TypeNameOf(elem_type) + " cannot be used as an element type of an array",
source);
return nullptr;
}
uint32_t el_align = elem_type->Align();
uint32_t el_size = elem_type->Size();
if (!validator_.NoDuplicateAttributes(arr->attributes)) {
return nullptr;
}
// Look for explicit stride via @stride(n) attribute
uint32_t explicit_stride = 0;
for (auto* attr : arr->attributes) {
Mark(attr);
if (auto* sd = attr->As<ast::StrideAttribute>()) {
explicit_stride = sd->stride;
if (!validator_.ArrayStrideAttribute(sd, el_size, el_align, source)) {
return nullptr;
}
continue;
}
AddError("attribute is not valid for array types", attr->source);
return nullptr;
}
// Calculate implicit stride
uint64_t implicit_stride = utils::RoundUp<uint64_t>(el_align, el_size);
uint64_t stride = explicit_stride ? explicit_stride : implicit_stride;
int64_t count = 0; // sem::Array uses a size of 0 for a runtime-sized array.
// Evaluate the constant array size expression.
if (auto* count_expr = arr->count) {
const auto* count_sem = Materialize(Expression(count_expr));
if (!count_sem) {
return nullptr;
}
auto* count_val = count_sem->ConstantValue();
if (!count_val) {
AddError("array size must evaluate to a constant integer expression",
count_expr->source);
return nullptr;
}
if (auto* ty = count_val->Type(); !ty->is_integer_scalar()) {
AddError("array size must evaluate to a constant integer expression, but is type '" +
builder_->FriendlyName(ty) + "'",
count_expr->source);
return nullptr;
}
count = count_val->As<AInt>();
if (count < 1) {
AddError("array size (" + std::to_string(count) + ") must be greater than 0",
count_expr->source);
return nullptr;
}
}
auto size = std::max<uint64_t>(static_cast<uint32_t>(count), 1u) * stride;
if (size > std::numeric_limits<uint32_t>::max()) {
std::stringstream msg;
msg << "array size (0x" << std::hex << size << ") must not exceed 0xffffffff bytes";
AddError(msg.str(), arr->source);
return nullptr;
}
auto* out = builder_->create<sem::Array>(
elem_type, static_cast<uint32_t>(count), el_align, static_cast<uint32_t>(size),
static_cast<uint32_t>(stride), static_cast<uint32_t>(implicit_stride));
if (!validator_.Array(out, source)) {
return nullptr;
}
if (elem_type->Is<sem::Atomic>()) {
atomic_composite_info_.emplace(out, arr->type->source);
} else {
auto found = atomic_composite_info_.find(elem_type);
if (found != atomic_composite_info_.end()) {
atomic_composite_info_.emplace(out, found->second);
}
}
return out;
}
sem::Type* Resolver::Alias(const ast::Alias* alias) {
auto* ty = Type(alias->type);
if (!ty) {
return nullptr;
}
if (!validator_.Alias(alias)) {
return nullptr;
}
return ty;
}
sem::Struct* Resolver::Structure(const ast::Struct* str) {
if (!validator_.NoDuplicateAttributes(str->attributes)) {
return nullptr;
}
for (auto* attr : str->attributes) {
Mark(attr);
}
sem::StructMemberList sem_members;
sem_members.reserve(str->members.size());
// Calculate the effective size and alignment of each field, and the overall
// size of the structure.
// For size, use the size attribute if provided, otherwise use the default
// size for the type.
// For alignment, use the alignment attribute if provided, otherwise use the
// default alignment for the member type.
// Diagnostic errors are raised if a basic rule is violated.
// Validation of storage-class rules requires analysing the actual variable
// usage of the structure, and so is performed as part of the variable
// validation.
uint64_t struct_size = 0;
uint64_t struct_align = 1;
std::unordered_map<Symbol, const ast::StructMember*> member_map;
for (auto* member : str->members) {
Mark(member);
auto result = member_map.emplace(member->symbol, member);
if (!result.second) {
AddError("redefinition of '" + builder_->Symbols().NameFor(member->symbol) + "'",
member->source);
AddNote("previous definition is here", result.first->second->source);
return nullptr;
}
// Resolve member type
auto* type = Type(member->type);
if (!type) {
return nullptr;
}
// validator_.Validate member type
if (!validator_.IsPlain(type)) {
AddError(sem_.TypeNameOf(type) + " cannot be used as the type of a structure member",
member->source);
return nullptr;
}
uint64_t offset = struct_size;
uint64_t align = type->Align();
uint64_t size = type->Size();
if (!validator_.NoDuplicateAttributes(member->attributes)) {
return nullptr;
}
bool has_offset_attr = false;
bool has_align_attr = false;
bool has_size_attr = false;
for (auto* attr : member->attributes) {
Mark(attr);
if (auto* o = attr->As<ast::StructMemberOffsetAttribute>()) {
// Offset attributes are not part of the WGSL spec, but are emitted
// by the SPIR-V reader.
if (o->offset < struct_size) {
AddError("offsets must be in ascending order", o->source);
return nullptr;
}
offset = o->offset;
align = 1;
has_offset_attr = true;
} else if (auto* a = attr->As<ast::StructMemberAlignAttribute>()) {
if (a->align <= 0 || !utils::IsPowerOfTwo(a->align)) {
AddError("align value must be a positive, power-of-two integer", a->source);
return nullptr;
}
align = a->align;
has_align_attr = true;
} else if (auto* s = attr->As<ast::StructMemberSizeAttribute>()) {
if (s->size < size) {
AddError("size must be at least as big as the type's size (" +
std::to_string(size) + ")",
s->source);
return nullptr;
}
size = s->size;
has_size_attr = true;
}
}
if (has_offset_attr && (has_align_attr || has_size_attr)) {
AddError("offset attributes cannot be used with align or size attributes",
member->source);
return nullptr;
}
offset = utils::RoundUp(align, offset);
if (offset > std::numeric_limits<uint32_t>::max()) {
std::stringstream msg;
msg << "struct member offset (0x" << std::hex << offset << ") must not exceed 0x"
<< std::hex << std::numeric_limits<uint32_t>::max() << " bytes";
AddError(msg.str(), member->source);
return nullptr;
}
auto* sem_member = builder_->create<sem::StructMember>(
member, member->symbol, type, static_cast<uint32_t>(sem_members.size()),
static_cast<uint32_t>(offset), static_cast<uint32_t>(align),
static_cast<uint32_t>(size));
builder_->Sem().Add(member, sem_member);
sem_members.emplace_back(sem_member);
struct_size = offset + size;
struct_align = std::max(struct_align, align);
}
uint64_t size_no_padding = struct_size;
struct_size = utils::RoundUp(struct_align, struct_size);
if (struct_size > std::numeric_limits<uint32_t>::max()) {
std::stringstream msg;
msg << "struct size (0x" << std::hex << struct_size << ") must not exceed 0xffffffff bytes";
AddError(msg.str(), str->source);
return nullptr;
}
if (struct_align > std::numeric_limits<uint32_t>::max()) {
TINT_ICE(Resolver, diagnostics_) << "calculated struct stride exceeds uint32";
return nullptr;
}
auto* out = builder_->create<sem::Struct>(
str, str->name, sem_members, static_cast<uint32_t>(struct_align),
static_cast<uint32_t>(struct_size), static_cast<uint32_t>(size_no_padding));
for (size_t i = 0; i < sem_members.size(); i++) {
auto* mem_type = sem_members[i]->Type();
if (mem_type->Is<sem::Atomic>()) {
atomic_composite_info_.emplace(out, sem_members[i]->Declaration()->source);
break;
} else {
auto found = atomic_composite_info_.find(mem_type);
if (found != atomic_composite_info_.end()) {
atomic_composite_info_.emplace(out, found->second);
break;
}
}
const_cast<sem::StructMember*>(sem_members[i])->SetStruct(out);
}
auto stage = current_function_ ? current_function_->Declaration()->PipelineStage()
: ast::PipelineStage::kNone;
if (!validator_.Structure(out, stage)) {
return nullptr;
}
return out;
}
sem::Statement* Resolver::ReturnStatement(const ast::ReturnStatement* stmt) {
auto* sem =
builder_->create<sem::Statement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
auto& behaviors = current_statement_->Behaviors();
behaviors = sem::Behavior::kReturn;
const sem::Type* value_ty = nullptr;
if (auto* value = stmt->value) {
const auto* expr = Expression(value);
if (!expr) {
return false;
}
if (auto* ret_ty = current_function_->ReturnType(); !ret_ty->Is<sem::Void>()) {
expr = Materialize(expr, ret_ty);
if (!expr) {
return false;
}
}
behaviors.Add(expr->Behaviors() - sem::Behavior::kNext);
value_ty = expr->Type()->UnwrapRef();
} else {
value_ty = builder_->create<sem::Void>();
}
// Validate after processing the return value expression so that its type
// is available for validation.
return validator_.Return(stmt, current_function_->ReturnType(), value_ty,
current_statement_);
});
}
sem::SwitchStatement* Resolver::SwitchStatement(const ast::SwitchStatement* stmt) {
auto* sem = builder_->create<sem::SwitchStatement>(stmt, current_compound_statement_,
current_function_);
return StatementScope(stmt, sem, [&] {
auto& behaviors = sem->Behaviors();
const auto* cond = Expression(stmt->condition);
if (!cond) {
return false;
}
behaviors = cond->Behaviors() - sem::Behavior::kNext;
auto* cond_ty = cond->Type()->UnwrapRef();
utils::UniqueVector<const sem::Type*> types;
types.add(cond_ty);
std::vector<sem::CaseStatement*> cases;
cases.reserve(stmt->body.size());
for (auto* case_stmt : stmt->body) {
Mark(case_stmt);
auto* c = CaseStatement(case_stmt);
if (!c) {
return false;
}
for (auto* expr : c->Selectors()) {
types.add(expr->Type()->UnwrapRef());
}
cases.emplace_back(c);
behaviors.Add(c->Behaviors());
sem->Cases().emplace_back(c);
}
// Determine the common type across all selectors and the switch expression
// This must materialize to an integer scalar (non-abstract).
auto* common_ty = sem::Type::Common(types.data(), types.size());
if (!common_ty || !common_ty->is_integer_scalar()) {
// No common type found or the common type was abstract.
// Pick i32 and let validation deal with any mismatches.
common_ty = builder_->create<sem::I32>();
}
cond = Materialize(cond, common_ty);
if (!cond) {
return false;
}
for (auto* c : cases) {
for (auto*& sel : c->Selectors()) { // Note: pointer reference
sel = Materialize(sel, common_ty);
if (!sel) {
return false;
}
}
}
if (behaviors.Contains(sem::Behavior::kBreak)) {
behaviors.Add(sem::Behavior::kNext);
}
behaviors.Remove(sem::Behavior::kBreak, sem::Behavior::kFallthrough);
return validator_.SwitchStatement(stmt);
});
}
sem::Statement* Resolver::VariableDeclStatement(const ast::VariableDeclStatement* stmt) {
auto* sem =
builder_->create<sem::Statement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
Mark(stmt->variable);
auto* variable = Variable(stmt->variable, /* is_global */ false);
if (!variable) {
return false;
}
for (auto* attr : stmt->variable->attributes) {
Mark(attr);
if (!attr->Is<ast::InternalAttribute>()) {
AddError("attributes are not valid on local variables", attr->source);
return false;
}
}
if (current_block_) { // Not all statements are inside a block
current_block_->AddDecl(stmt->variable);
}
if (auto* ctor = variable->Constructor()) {
sem->Behaviors() = ctor->Behaviors();
}
return validator_.LocalVariable(variable);
});
}
sem::Statement* Resolver::AssignmentStatement(const ast::AssignmentStatement* stmt) {
auto* sem =
builder_->create<sem::Statement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
auto* lhs = Expression(stmt->lhs);
if (!lhs) {
return false;
}
const bool is_phony_assignment = stmt->lhs->Is<ast::PhonyExpression>();
const auto* rhs = Expression(stmt->rhs);
if (!rhs) {
return false;
}
if (!is_phony_assignment) {
rhs = Materialize(rhs, lhs->Type()->UnwrapRef());
if (!rhs) {
return false;
}
}
auto& behaviors = sem->Behaviors();
behaviors = rhs->Behaviors();
if (!is_phony_assignment) {
behaviors.Add(lhs->Behaviors());
}
return validator_.Assignment(stmt, sem_.TypeOf(stmt->rhs));
});
}
sem::Statement* Resolver::BreakStatement(const ast::BreakStatement* stmt) {
auto* sem =
builder_->create<sem::Statement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
sem->Behaviors() = sem::Behavior::kBreak;
return validator_.BreakStatement(sem, current_statement_);
});
}
sem::Statement* Resolver::CallStatement(const ast::CallStatement* stmt) {
auto* sem =
builder_->create<sem::Statement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
if (auto* expr = Expression(stmt->expr)) {
sem->Behaviors() = expr->Behaviors();
return true;
}
return false;
});
}
sem::Statement* Resolver::CompoundAssignmentStatement(
const ast::CompoundAssignmentStatement* stmt) {
auto* sem =
builder_->create<sem::Statement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
auto* lhs = Expression(stmt->lhs);
if (!lhs) {
return false;
}
auto* rhs = Expression(stmt->rhs);
if (!rhs) {
return false;
}
sem->Behaviors() = rhs->Behaviors() + lhs->Behaviors();
auto* lhs_ty = lhs->Type()->UnwrapRef();
auto* rhs_ty = rhs->Type()->UnwrapRef();
auto* ty = intrinsic_table_->Lookup(stmt->op, lhs_ty, rhs_ty, stmt->source, true).result;
if (!ty) {
return false;
}
return validator_.Assignment(stmt, ty);
});
}
sem::Statement* Resolver::ContinueStatement(const ast::ContinueStatement* stmt) {
auto* sem =
builder_->create<sem::Statement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
sem->Behaviors() = sem::Behavior::kContinue;
// Set if we've hit the first continue statement in our parent loop
if (auto* block = sem->FindFirstParent<sem::LoopBlockStatement>()) {
if (!block->FirstContinue()) {
const_cast<sem::LoopBlockStatement*>(block)->SetFirstContinue(
stmt, block->Decls().size());
}
}
return validator_.ContinueStatement(sem, current_statement_);
});
}
sem::Statement* Resolver::DiscardStatement(const ast::DiscardStatement* stmt) {
auto* sem =
builder_->create<sem::Statement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
sem->Behaviors() = sem::Behavior::kDiscard;
current_function_->SetHasDiscard();
return validator_.DiscardStatement(sem, current_statement_);
});
}
sem::Statement* Resolver::FallthroughStatement(const ast::FallthroughStatement* stmt) {
auto* sem =
builder_->create<sem::Statement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
sem->Behaviors() = sem::Behavior::kFallthrough;
return validator_.FallthroughStatement(sem);
});
}
sem::Statement* Resolver::IncrementDecrementStatement(
const ast::IncrementDecrementStatement* stmt) {
auto* sem =
builder_->create<sem::Statement>(stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
auto* lhs = Expression(stmt->lhs);
if (!lhs) {
return false;
}
sem->Behaviors() = lhs->Behaviors();
return validator_.IncrementDecrementStatement(stmt);
});
}
bool Resolver::ApplyStorageClassUsageToType(ast::StorageClass sc,
sem::Type* ty,
const Source& usage) {
ty = const_cast<sem::Type*>(ty->UnwrapRef());
if (auto* str = ty->As<sem::Struct>()) {
if (str->StorageClassUsage().count(sc)) {
return true; // Already applied
}
str->AddUsage(sc);
for (auto* member : str->Members()) {
if (!ApplyStorageClassUsageToType(sc, member->Type(), usage)) {
std::stringstream err;
err << "while analysing structure member " << sem_.TypeNameOf(str) << "."
<< builder_->Symbols().NameFor(member->Declaration()->symbol);
AddNote(err.str(), member->Declaration()->source);
return false;
}
}
return true;
}
if (auto* arr = ty->As<sem::Array>()) {
if (arr->IsRuntimeSized() && sc != ast::StorageClass::kStorage) {
AddError(
"runtime-sized arrays can only be used in the <storage> storage "
"class",
usage);
return false;
}
return ApplyStorageClassUsageToType(sc, const_cast<sem::Type*>(arr->ElemType()), usage);
}
if (ast::IsHostShareable(sc) && !validator_.IsHostShareable(ty)) {
std::stringstream err;
err << "Type '" << sem_.TypeNameOf(ty) << "' cannot be used in storage class '" << sc
<< "' as it is non-host-shareable";
AddError(err.str(), usage);
return false;
}
return true;
}
template <typename SEM, typename F>
SEM* Resolver::StatementScope(const ast::Statement* ast, SEM* sem, F&& callback) {
builder_->Sem().Add(ast, sem);
auto* as_compound = As<sem::CompoundStatement, CastFlags::kDontErrorOnImpossibleCast>(sem);
auto* as_block = As<sem::BlockStatement, CastFlags::kDontErrorOnImpossibleCast>(sem);
TINT_SCOPED_ASSIGNMENT(current_statement_, sem);
TINT_SCOPED_ASSIGNMENT(current_compound_statement_,
as_compound ? as_compound : current_compound_statement_);
TINT_SCOPED_ASSIGNMENT(current_block_, as_block ? as_block : current_block_);
if (!callback()) {
return nullptr;
}
return sem;
}
bool Resolver::Mark(const ast::Node* node) {
if (node == nullptr) {
TINT_ICE(Resolver, diagnostics_) << "Resolver::Mark() called with nullptr";
return false;
}
if (marked_.emplace(node).second) {
return true;
}
TINT_ICE(Resolver, diagnostics_) << "AST node '" << node->TypeInfo().name
<< "' was encountered twice in the same AST of a Program\n"
<< "At: " << node->source << "\n"
<< "Pointer: " << node;
return false;
}
void Resolver::AddError(const std::string& msg, const Source& source) const {
diagnostics_.add_error(diag::System::Resolver, msg, source);
}
void Resolver::AddWarning(const std::string& msg, const Source& source) const {
diagnostics_.add_warning(diag::System::Resolver, msg, source);
}
void Resolver::AddNote(const std::string& msg, const Source& source) const {
diagnostics_.add_note(diag::System::Resolver, msg, source);
}
bool Resolver::IsBuiltin(Symbol symbol) const {
std::string name = builder_->Symbols().NameFor(symbol);
return sem::ParseBuiltinType(name) != sem::BuiltinType::kNone;
}
} // namespace tint::resolver