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dawn / tint / ea3eee988528af5802707ee07d89c48eba4a6e85 / . / src / resolver / resolver.cc
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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/resolver/resolver.h"
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <limits>
#include <utility>
#include "src/ast/alias.h"
#include "src/ast/array.h"
#include "src/ast/assignment_statement.h"
#include "src/ast/bitcast_expression.h"
#include "src/ast/break_statement.h"
#include "src/ast/call_statement.h"
#include "src/ast/continue_statement.h"
#include "src/ast/depth_texture.h"
#include "src/ast/disable_validation_decoration.h"
#include "src/ast/discard_statement.h"
#include "src/ast/fallthrough_statement.h"
#include "src/ast/for_loop_statement.h"
#include "src/ast/if_statement.h"
#include "src/ast/internal_decoration.h"
#include "src/ast/interpolate_decoration.h"
#include "src/ast/loop_statement.h"
#include "src/ast/matrix.h"
#include "src/ast/override_decoration.h"
#include "src/ast/pointer.h"
#include "src/ast/return_statement.h"
#include "src/ast/sampled_texture.h"
#include "src/ast/sampler.h"
#include "src/ast/storage_texture.h"
#include "src/ast/struct_block_decoration.h"
#include "src/ast/switch_statement.h"
#include "src/ast/traverse_expressions.h"
#include "src/ast/type_name.h"
#include "src/ast/unary_op_expression.h"
#include "src/ast/variable_decl_statement.h"
#include "src/ast/vector.h"
#include "src/ast/workgroup_decoration.h"
#include "src/sem/array.h"
#include "src/sem/atomic_type.h"
#include "src/sem/call.h"
#include "src/sem/depth_multisampled_texture_type.h"
#include "src/sem/depth_texture_type.h"
#include "src/sem/for_loop_statement.h"
#include "src/sem/function.h"
#include "src/sem/if_statement.h"
#include "src/sem/loop_statement.h"
#include "src/sem/member_accessor_expression.h"
#include "src/sem/multisampled_texture_type.h"
#include "src/sem/pointer_type.h"
#include "src/sem/reference_type.h"
#include "src/sem/sampled_texture_type.h"
#include "src/sem/sampler_type.h"
#include "src/sem/statement.h"
#include "src/sem/storage_texture_type.h"
#include "src/sem/struct.h"
#include "src/sem/switch_statement.h"
#include "src/sem/type_constructor.h"
#include "src/sem/type_conversion.h"
#include "src/sem/variable.h"
#include "src/utils/defer.h"
#include "src/utils/math.h"
#include "src/utils/reverse.h"
#include "src/utils/scoped_assignment.h"
#include "src/utils/transform.h"
namespace tint {
namespace resolver {
Resolver::Resolver(ProgramBuilder* builder)
: builder_(builder),
diagnostics_(builder->Diagnostics()),
intrinsic_table_(IntrinsicTable::Create(*builder)) {}
Resolver::~Resolver() = default;
bool Resolver::Resolve() {
if (builder_->Diagnostics().contains_errors()) {
return false;
}
if (!DependencyGraph::Build(builder_->AST(), builder_->Symbols(),
builder_->Diagnostics(), dependencies_,
/* allow_out_of_order_decls*/ false)) {
return false;
}
bool result = ResolveInternal();
if (!result && !diagnostics_.contains_errors()) {
TINT_ICE(Resolver, diagnostics_)
<< "resolving failed, but no error was raised";
return false;
}
return result;
}
bool Resolver::ResolveInternal() {
Mark(&builder_->AST());
// Process everything else in the order they appear in the module. This is
// necessary for validation of use-before-declaration.
for (auto* decl : builder_->AST().GlobalDeclarations()) {
if (auto* td = decl->As<ast::TypeDecl>()) {
Mark(td);
if (!TypeDecl(td)) {
return false;
}
} else if (auto* func = decl->As<ast::Function>()) {
Mark(func);
if (!Function(func)) {
return false;
}
} else if (auto* var = decl->As<ast::Variable>()) {
Mark(var);
if (!GlobalVariable(var)) {
return false;
}
} else {
TINT_UNREACHABLE(Resolver, diagnostics_)
<< "unhandled global declaration: " << decl->TypeInfo().name;
return false;
}
}
AllocateOverridableConstantIds();
SetShadows();
if (!ValidatePipelineStages()) {
return false;
}
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 = [&]() -> sem::Type* {
if (ty->Is<ast::Void>()) {
return builder_->create<sem::Void>();
}
if (ty->Is<ast::Bool>()) {
return builder_->create<sem::Bool>();
}
if (ty->Is<ast::I32>()) {
return builder_->create<sem::I32>();
}
if (ty->Is<ast::U32>()) {
return builder_->create<sem::U32>();
}
if (ty->Is<ast::F32>()) {
return builder_->create<sem::F32>();
}
if (auto* t = ty->As<ast::Vector>()) {
if (auto* el = Type(t->type)) {
if (auto* vector = builder_->create<sem::Vector>(el, t->width)) {
if (ValidateVector(vector, t->source)) {
return vector;
}
}
}
return nullptr;
}
if (auto* t = ty->As<ast::Matrix>()) {
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 (ValidateMatrix(matrix, t->source)) {
return matrix;
}
}
}
}
return nullptr;
}
if (auto* t = ty->As<ast::Array>()) {
return Array(t);
}
if (auto* t = ty->As<ast::Atomic>()) {
if (auto* el = Type(t->type)) {
auto* a = builder_->create<sem::Atomic>(el);
if (!ValidateAtomic(t, a)) {
return nullptr;
}
return a;
}
return nullptr;
}
if (auto* t = ty->As<ast::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;
}
if (auto* t = ty->As<ast::Sampler>()) {
return builder_->create<sem::Sampler>(t->kind);
}
if (auto* t = ty->As<ast::SampledTexture>()) {
if (auto* el = Type(t->type)) {
return builder_->create<sem::SampledTexture>(t->dim, el);
}
return nullptr;
}
if (auto* t = ty->As<ast::MultisampledTexture>()) {
if (auto* el = Type(t->type)) {
return builder_->create<sem::MultisampledTexture>(t->dim, el);
}
return nullptr;
}
if (auto* t = ty->As<ast::DepthTexture>()) {
return builder_->create<sem::DepthTexture>(t->dim);
}
if (auto* t = ty->As<ast::DepthMultisampledTexture>()) {
return builder_->create<sem::DepthMultisampledTexture>(t->dim);
}
if (auto* t = ty->As<ast::StorageTexture>()) {
if (auto* el = Type(t->type)) {
if (!ValidateStorageTexture(t)) {
return nullptr;
}
return builder_->create<sem::StorageTexture>(t->dim, t->format,
t->access, el);
}
return nullptr;
}
if (ty->As<ast::ExternalTexture>()) {
return builder_->create<sem::ExternalTexture>();
}
if (auto* type = ResolvedSymbol<sem::Type>(ty)) {
return type;
}
TINT_UNREACHABLE(Resolver, diagnostics_)
<< "Unhandled ast::Type: " << ty->TypeInfo().name;
return nullptr;
}();
if (s) {
builder_->Sem().Add(ty, s);
}
return s;
}
sem::Variable* Resolver::Variable(const ast::Variable* var,
VariableKind kind,
uint32_t index /* = 0 */) {
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 = Expression(var->constructor);
if (!rhs) {
return nullptr;
}
// If the variable has no declared type, infer it from the RHS
if (!storage_ty) {
if (!var->is_const && kind == VariableKind::kGlobal) {
AddError("global var declaration must specify a type", var->source);
return nullptr;
}
storage_ty = rhs->Type()->UnwrapRef(); // Implicit load of RHS
}
} else if (var->is_const && kind != VariableKind::kParameter &&
!ast::HasDecoration<ast::OverrideDecoration>(var->decorations)) {
AddError("let declaration must have an initializer", var->source);
return nullptr;
} else if (!var->type) {
AddError(
(kind == VariableKind::kGlobal)
? "module scope var declaration requires a type and initializer"
: "function scope var declaration requires a type or initializer",
var->source);
return nullptr;
}
if (!storage_ty) {
TINT_ICE(Resolver, diagnostics_)
<< "failed to determine storage type for variable '" +
builder_->Symbols().NameFor(var->symbol) + "'\n"
<< "Source: " << var->source;
return nullptr;
}
auto storage_class = var->declared_storage_class;
if (storage_class == ast::StorageClass::kNone && !var->is_const) {
// No declared storage class. Infer from usage / type.
if (kind == VariableKind::kLocal) {
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 decoration. The
// storage class will always be handle.
storage_class = ast::StorageClass::kUniformConstant;
}
}
if (kind == VariableKind::kLocal && !var->is_const &&
storage_class != ast::StorageClass::kFunction &&
IsValidationEnabled(var->decorations,
ast::DisabledValidation::kIgnoreStorageClass)) {
AddError("function variable has a non-function storage class", var->source);
return nullptr;
}
auto access = var->declared_access;
if (access == ast::Access::kUndefined) {
access = DefaultAccessForStorageClass(storage_class);
}
auto* var_ty = storage_ty;
if (!var->is_const) {
// Variable declaration. Unlike `let`, `var` has storage.
// Variables are always of a reference type to the declared storage type.
var_ty =
builder_->create<sem::Reference>(storage_ty, storage_class, access);
}
if (rhs && !ValidateVariableConstructorOrCast(var, storage_class, storage_ty,
rhs->Type())) {
return nullptr;
}
if (!ApplyStorageClassUsageToType(
storage_class, const_cast<sem::Type*>(var_ty), var->source)) {
AddNote(
std::string("while instantiating ") +
((kind == VariableKind::kParameter) ? "parameter " : "variable ") +
builder_->Symbols().NameFor(var->symbol),
var->source);
return nullptr;
}
if (kind == VariableKind::kParameter) {
if (auto* ptr = var_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()),
var->source)) {
AddNote("while instantiating parameter " +
builder_->Symbols().NameFor(var->symbol),
var->source);
return nullptr;
}
}
}
switch (kind) {
case VariableKind::kGlobal: {
sem::BindingPoint binding_point;
if (auto bp = var->BindingPoint()) {
binding_point = {bp.group->value, bp.binding->value};
}
auto* override =
ast::GetDecoration<ast::OverrideDecoration>(var->decorations);
bool has_const_val = rhs && var->is_const && !override;
auto* global = builder_->create<sem::GlobalVariable>(
var, var_ty, storage_class, access,
has_const_val ? rhs->ConstantValue() : sem::Constant{},
binding_point);
if (override) {
global->SetIsOverridable();
if (override->has_value) {
global->SetConstantId(static_cast<uint16_t>(override->value));
}
}
global->SetConstructor(rhs);
builder_->Sem().Add(var, global);
return global;
}
case VariableKind::kLocal: {
auto* local = builder_->create<sem::LocalVariable>(
var, var_ty, storage_class, access, current_statement_,
(rhs && var->is_const) ? rhs->ConstantValue() : sem::Constant{});
builder_->Sem().Add(var, local);
local->SetConstructor(rhs);
return local;
}
case VariableKind::kParameter: {
auto* param = builder_->create<sem::Parameter>(var, index, var_ty,
storage_class, access);
builder_->Sem().Add(var, param);
return param;
}
}
TINT_UNREACHABLE(Resolver, diagnostics_)
<< "unhandled VariableKind " << static_cast<int>(kind);
return nullptr;
}
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::kUniformConstant:
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* var = decl->As<ast::Variable>();
if (!var) {
continue;
}
auto* override_deco =
ast::GetDecoration<ast::OverrideDecoration>(var->decorations);
if (!override_deco) {
continue;
}
uint16_t constant_id;
if (override_deco->has_value) {
constant_id = static_cast<uint16_t>(override_deco->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<sem::GlobalVariable>(var);
const_cast<sem::GlobalVariable*>(sem)->SetConstantId(constant_id);
}
}
void Resolver::SetShadows() {
for (auto it : dependencies_.shadows) {
auto* var = Sem(it.first);
if (auto* local = var->As<sem::LocalVariable>()) {
local->SetShadows(Sem(it.second));
}
if (auto* param = var->As<sem::Parameter>()) {
param->SetShadows(Sem(it.second));
}
}
} // namespace resolver
bool Resolver::GlobalVariable(const ast::Variable* var) {
auto* sem = Variable(var, VariableKind::kGlobal);
if (!sem) {
return false;
}
auto storage_class = sem->StorageClass();
if (!var->is_const && storage_class == ast::StorageClass::kNone) {
AddError("global variables must have a storage class", var->source);
return false;
}
if (var->is_const && storage_class != ast::StorageClass::kNone) {
AddError("global constants shouldn't have a storage class", var->source);
return false;
}
for (auto* deco : var->decorations) {
Mark(deco);
if (auto* override_deco = deco->As<ast::OverrideDecoration>()) {
// Track the constant IDs that are specified in the shader.
if (override_deco->has_value) {
constant_ids_.emplace(override_deco->value, sem);
}
}
}
if (!ValidateNoDuplicateDecorations(var->decorations)) {
return false;
}
if (!ValidateGlobalVariable(sem)) {
return false;
}
// TODO(bclayton): Call this at the end of resolve on all uniform and storage
// referenced structs
if (!ValidateStorageClassLayout(sem)) {
return false;
}
return true;
}
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* var = As<sem::Parameter>(
Variable(param, VariableKind::kParameter, parameter_index++));
if (!var) {
return nullptr;
}
for (auto* deco : param->decorations) {
Mark(deco);
}
if (!ValidateNoDuplicateDecorations(param->decorations)) {
return nullptr;
}
parameters.emplace_back(var);
auto* var_ty = const_cast<sem::Type*>(var->Type());
if (auto* str = var_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* deco : decl->decorations) {
Mark(deco);
}
if (!ValidateNoDuplicateDecorations(decl->decorations)) {
return nullptr;
}
for (auto* deco : decl->return_type_decorations) {
Mark(deco);
}
if (!ValidateNoDuplicateDecorations(decl->return_type_decorations)) {
return nullptr;
}
if (!ValidateFunction(func)) {
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 (int i = 0; i < 3; i++) {
ws[i].value = 1;
ws[i].overridable_const = nullptr;
}
auto* deco = ast::GetDecoration<ast::WorkgroupDecoration>(func->decorations);
if (!deco) {
return true;
}
auto values = deco->Values();
auto any_i32 = false;
auto any_u32 = false;
for (int i = 0; i < 3; i++) {
// Each argument to this decoration can either be a literal, an
// identifier for a module-scope constants, or nullptr if not specified.
auto* expr = values[i];
if (!expr) {
// Not specified, just use the default.
continue;
}
auto* expr_sem = Expression(expr);
if (!expr_sem) {
return false;
}
constexpr const char* kErrBadType =
"workgroup_size argument must be either literal or module-scope "
"constant of type i32 or u32";
constexpr const char* kErrInconsistentType =
"workgroup_size arguments must be of the same type, either i32 "
"or u32";
auto* ty = TypeOf(expr);
bool is_i32 = ty->UnwrapRef()->Is<sem::I32>();
bool is_u32 = ty->UnwrapRef()->Is<sem::U32>();
if (!is_i32 && !is_u32) {
AddError(kErrBadType, expr->source);
return false;
}
any_i32 = any_i32 || is_i32;
any_u32 = any_u32 || is_u32;
if (any_i32 && any_u32) {
AddError(kErrInconsistentType, expr->source);
return false;
}
sem::Constant value;
if (auto* user = Sem(expr)->As<sem::VariableUser>()) {
// We have an variable of a module-scope constant.
auto* decl = user->Variable()->Declaration();
if (!decl->is_const) {
AddError(kErrBadType, expr->source);
return false;
}
// Capture the constant if an [[override]] attribute is present.
if (ast::HasDecoration<ast::OverrideDecoration>(decl->decorations)) {
ws[i].overridable_const = decl;
}
if (decl->constructor) {
value = Sem(decl->constructor)->ConstantValue();
} else {
// No constructor means this value must be overriden by the user.
ws[i].value = 0;
continue;
}
} else if (expr->Is<ast::LiteralExpression>()) {
value = Sem(expr)->ConstantValue();
} else {
AddError(
"workgroup_size argument must be either a literal or a "
"module-scope constant",
values[i]->source);
return false;
}
if (!value) {
TINT_ICE(Resolver, diagnostics_)
<< "could not resolve constant workgroup_size constant value";
continue;
}
// Validate and set the default value for this dimension.
if (is_i32 ? value.Elements()[0].i32 < 1 : value.Elements()[0].u32 < 1) {
AddError("workgroup_size argument must be at least 1", values[i]->source);
return false;
}
ws[i].value = is_i32 ? static_cast<uint32_t>(value.Elements()[0].i32)
: value.Elements()[0].u32;
}
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 (!ValidateStatements(stmts)) {
return false;
}
return true;
}
sem::Statement* Resolver::Statement(const ast::Statement* stmt) {
if (stmt->Is<ast::CaseStatement>()) {
AddError("case statement can only be used inside a switch statement",
stmt->source);
return nullptr;
}
if (stmt->Is<ast::ElseStatement>()) {
TINT_ICE(Resolver, diagnostics_)
<< "Resolver::Statement() encountered an Else statement. Else "
"statements are embedded in If statements, so should never be "
"encountered as top-level statements";
return nullptr;
}
// Compound statements. These create their own sem::CompoundStatement
// bindings.
if (auto* b = stmt->As<ast::BlockStatement>()) {
return BlockStatement(b);
}
if (auto* l = stmt->As<ast::ForLoopStatement>()) {
return ForLoopStatement(l);
}
if (auto* l = stmt->As<ast::LoopStatement>()) {
return LoopStatement(l);
}
if (auto* i = stmt->As<ast::IfStatement>()) {
return IfStatement(i);
}
if (auto* s = stmt->As<ast::SwitchStatement>()) {
return SwitchStatement(s);
}
// Non-Compound statements
if (auto* a = stmt->As<ast::AssignmentStatement>()) {
return AssignmentStatement(a);
}
if (auto* b = stmt->As<ast::BreakStatement>()) {
return BreakStatement(b);
}
if (auto* c = stmt->As<ast::CallStatement>()) {
return CallStatement(c);
}
if (auto* c = stmt->As<ast::ContinueStatement>()) {
return ContinueStatement(c);
}
if (auto* d = stmt->As<ast::DiscardStatement>()) {
return DiscardStatement(d);
}
if (auto* f = stmt->As<ast::FallthroughStatement>()) {
return FallthroughStatement(f);
}
if (auto* r = stmt->As<ast::ReturnStatement>()) {
return ReturnStatement(r);
}
if (auto* v = stmt->As<ast::VariableDeclStatement>()) {
return VariableDeclStatement(v);
}
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, [&] {
for (auto* sel : stmt->selectors) {
Mark(sel);
}
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());
for (auto* else_stmt : stmt->else_statements) {
Mark(else_stmt);
auto* else_sem = ElseStatement(else_stmt);
if (!else_sem) {
return false;
}
sem->Behaviors().Add(else_sem->Behaviors());
}
if (stmt->else_statements.empty() ||
stmt->else_statements.back()->condition != nullptr) {
// 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 ValidateIfStatement(sem);
});
}
sem::ElseStatement* Resolver::ElseStatement(const ast::ElseStatement* stmt) {
auto* sem = builder_->create<sem::ElseStatement>(
stmt, current_compound_statement_, current_function_);
return StatementScope(stmt, sem, [&] {
if (auto* cond_expr = stmt->condition) {
auto* cond = Expression(cond_expr);
if (!cond) {
return false;
}
sem->SetCondition(cond);
// https://www.w3.org/TR/WGSL/#behaviors-rules
// if statements with else if branches are treated as if they were nested
// simple if/else statements
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());
return ValidateElseStatement(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);
if (!stmt->continuing->Empty()) {
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 true;
});
});
}
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 ValidateForLoopStatement(sem);
});
}
sem::Expression* Resolver::Expression(const ast::Expression* root) {
std::vector<const ast::Expression*> sorted;
bool mark_failed = false;
if (!ast::TraverseExpressions<ast::TraverseOrder::RightToLeft>(
root, diagnostics_, [&](const ast::Expression* expr) {
if (!Mark(expr)) {
mark_failed = true;
return ast::TraverseAction::Stop;
}
sorted.emplace_back(expr);
return ast::TraverseAction::Descend;
})) {
return nullptr;
}
if (mark_failed) {
return nullptr;
}
for (auto* expr : utils::Reverse(sorted)) {
sem::Expression* sem_expr = nullptr;
if (auto* array = expr->As<ast::IndexAccessorExpression>()) {
sem_expr = IndexAccessor(array);
} else if (auto* bin_op = expr->As<ast::BinaryExpression>()) {
sem_expr = Binary(bin_op);
} else if (auto* bitcast = expr->As<ast::BitcastExpression>()) {
sem_expr = Bitcast(bitcast);
} else if (auto* call = expr->As<ast::CallExpression>()) {
sem_expr = Call(call);
} else if (auto* ident = expr->As<ast::IdentifierExpression>()) {
sem_expr = Identifier(ident);
} else if (auto* literal = expr->As<ast::LiteralExpression>()) {
sem_expr = Literal(literal);
} else if (auto* member = expr->As<ast::MemberAccessorExpression>()) {
sem_expr = MemberAccessor(member);
} else if (auto* unary = expr->As<ast::UnaryOpExpression>()) {
sem_expr = UnaryOp(unary);
} else if (expr->Is<ast::PhonyExpression>()) {
sem_expr = builder_->create<sem::Expression>(
expr, builder_->create<sem::Void>(), current_statement_,
sem::Constant{});
} else {
TINT_ICE(Resolver, diagnostics_)
<< "unhandled expression type: " << expr->TypeInfo().name;
return nullptr;
}
if (!sem_expr) {
return nullptr;
}
// https://www.w3.org/TR/WGSL/#behaviors-rules
// an expression behavior is always either {Next} or {Next, Discard}
if (sem_expr->Behaviors() != sem::Behavior::kNext &&
sem_expr->Behaviors() != sem::Behaviors{sem::Behavior::kNext, // NOLINT
sem::Behavior::kDiscard} &&
!IsCallStatement(expr)) {
TINT_ICE(Resolver, diagnostics_)
<< expr->TypeInfo().name
<< " behaviors are: " << sem_expr->Behaviors();
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;
}
sem::Expression* Resolver::IndexAccessor(
const ast::IndexAccessorExpression* expr) {
auto* idx = Sem(expr->index);
auto* obj = Sem(expr->object);
auto* obj_raw_ty = obj->Type();
auto* obj_ty = obj_raw_ty->UnwrapRef();
const sem::Type* ty = nullptr;
if (auto* arr = obj_ty->As<sem::Array>()) {
ty = arr->ElemType();
} else if (auto* vec = obj_ty->As<sem::Vector>()) {
ty = vec->type();
} else if (auto* mat = obj_ty->As<sem::Matrix>()) {
ty = builder_->create<sem::Vector>(mat->type(), mat->rows());
} else {
AddError("cannot index type '" + TypeNameOf(obj_ty) + "'", expr->source);
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: '" +
TypeNameOf(idx_ty) + "'",
idx->Declaration()->source);
return nullptr;
}
if (obj_ty->IsAnyOf<sem::Array, sem::Matrix>()) {
if (!obj_raw_ty->Is<sem::Reference>()) {
// TODO(bclayton): expand this to allow any const_expr expression
// https://github.com/gpuweb/gpuweb/issues/1272
if (!idx->Declaration()->As<ast::IntLiteralExpression>()) {
AddError("index must be signed or unsigned integer literal",
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 val = EvaluateConstantValue(expr, ty);
auto* sem =
builder_->create<sem::Expression>(expr, ty, current_statement_, val);
sem->Behaviors() = idx->Behaviors() + obj->Behaviors();
return sem;
}
sem::Expression* Resolver::Bitcast(const ast::BitcastExpression* expr) {
auto* inner = Sem(expr->expr);
auto* ty = Type(expr->type);
if (!ty) {
return nullptr;
}
if (ty->Is<sem::Pointer>()) {
AddError("cannot cast to a pointer", expr->source);
return nullptr;
}
auto val = EvaluateConstantValue(expr, ty);
auto* sem =
builder_->create<sem::Expression>(expr, ty, current_statement_, val);
sem->Behaviors() = inner->Behaviors();
return sem;
}
sem::Call* Resolver::Call(const ast::CallExpression* expr) {
std::vector<const sem::Expression*> args(expr->args.size());
std::vector<const sem::Type*> arg_tys(args.size());
sem::Behaviors arg_behaviors;
for (size_t i = 0; i < expr->args.size(); i++) {
auto* arg = Sem(expr->args[i]);
if (!arg) {
return nullptr;
}
args[i] = arg;
arg_tys[i] = args[i]->Type();
arg_behaviors.Add(arg->Behaviors());
}
arg_behaviors.Remove(sem::Behavior::kNext);
auto type_ctor_or_conv = [&](const sem::Type* ty) -> sem::Call* {
// The call has resolved to a type constructor or cast.
if (args.size() == 1) {
auto* target = ty;
auto* source = args[0]->Type()->UnwrapRef();
if ((source != target) && //
((source->is_scalar() && target->is_scalar()) ||
(source->Is<sem::Vector>() && target->Is<sem::Vector>()) ||
(source->Is<sem::Matrix>() && target->Is<sem::Matrix>()))) {
// Note: Matrix types currently cannot be converted (the element type
// must only be f32). We implement this for the day we support other
// matrix element types.
return TypeConversion(expr, ty, args[0], arg_tys[0]);
}
}
return TypeConstructor(expr, ty, std::move(args), std::move(arg_tys));
};
// Resolve the target of the CallExpression to determine whether this is a
// function call, cast or type constructor expression.
if (expr->target.type) {
auto* ty = Type(expr->target.type);
if (!ty) {
return nullptr;
}
return type_ctor_or_conv(ty);
}
auto* ident = expr->target.name;
Mark(ident);
auto* resolved = ResolvedSymbol(ident);
if (auto* ty = As<sem::Type>(resolved)) {
return type_ctor_or_conv(ty);
}
if (auto* fn = As<sem::Function>(resolved)) {
return FunctionCall(expr, fn, std::move(args), arg_behaviors);
}
auto name = builder_->Symbols().NameFor(ident->symbol);
auto intrinsic_type = sem::ParseIntrinsicType(name);
if (intrinsic_type != sem::IntrinsicType::kNone) {
return IntrinsicCall(expr, intrinsic_type, std::move(args),
std::move(arg_tys));
}
TINT_ICE(Resolver, diagnostics_)
<< expr->source << " unresolved CallExpression target:\n"
<< "resolved: " << (resolved ? resolved->TypeInfo().name : "<null>")
<< "\n"
<< "name: " << builder_->Symbols().NameFor(ident->symbol);
return nullptr;
}
sem::Call* Resolver::IntrinsicCall(
const ast::CallExpression* expr,
sem::IntrinsicType intrinsic_type,
const std::vector<const sem::Expression*> args,
const std::vector<const sem::Type*> arg_tys) {
auto* intrinsic = intrinsic_table_->Lookup(intrinsic_type, std::move(arg_tys),
expr->source);
if (!intrinsic) {
return nullptr;
}
if (intrinsic->IsDeprecated()) {
AddWarning("use of deprecated intrinsic", expr->source);
}
auto* call = builder_->create<sem::Call>(expr, intrinsic, std::move(args),
current_statement_, sem::Constant{});
current_function_->AddDirectlyCalledIntrinsic(intrinsic);
if (IsTextureIntrinsic(intrinsic_type) &&
!ValidateTextureIntrinsicFunction(call)) {
return nullptr;
}
if (!ValidateIntrinsicCall(call)) {
return nullptr;
}
current_function_->AddDirectCall(call);
return call;
}
sem::Call* Resolver::FunctionCall(
const ast::CallExpression* expr,
sem::Function* target,
const std::vector<const sem::Expression*> args,
sem::Behaviors arg_behaviors) {
auto sym = expr->target.name->symbol;
auto name = builder_->Symbols().NameFor(sym);
auto* call = builder_->create<sem::Call>(expr, target, std::move(args),
current_statement_, sem::Constant{});
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);
}
}
target->AddCallSite(call);
call->Behaviors() = arg_behaviors + target->Behaviors();
if (!ValidateFunctionCall(call)) {
return nullptr;
}
return call;
}
sem::Call* Resolver::TypeConversion(const ast::CallExpression* expr,
const sem::Type* target,
const sem::Expression* arg,
const sem::Type* source) {
// It is not valid to have a type-cast call expression inside a call
// statement.
if (IsCallStatement(expr)) {
AddError("type cast evaluated but not used", expr->source);
return nullptr;
}
auto* call_target = utils::GetOrCreate(
type_conversions_, TypeConversionSig{target, source},
[&]() -> sem::TypeConversion* {
// Now that the argument types have been determined, make sure that they
// obey the conversion rules laid out in
// https://gpuweb.github.io/gpuweb/wgsl/#conversion-expr.
bool ok = true;
if (auto* vec_type = target->As<sem::Vector>()) {
ok = ValidateVectorConstructorOrCast(expr, vec_type);
} else if (auto* mat_type = target->As<sem::Matrix>()) {
// Note: Matrix types currently cannot be converted (the element type
// must only be f32). We implement this for the day we support other
// matrix element types.
ok = ValidateMatrixConstructorOrCast(expr, mat_type);
} else if (target->is_scalar()) {
ok = ValidateScalarConstructorOrCast(expr, target);
} else if (auto* arr_type = target->As<sem::Array>()) {
ok = ValidateArrayConstructorOrCast(expr, arr_type);
} else if (auto* struct_type = target->As<sem::Struct>()) {
ok = ValidateStructureConstructorOrCast(expr, struct_type);
} else {
AddError("type is not constructible", expr->source);
return nullptr;
}
if (!ok) {
return nullptr;
}
auto* param = builder_->create<sem::Parameter>(
nullptr, // declaration
0, // index
source->UnwrapRef(), // type
ast::StorageClass::kNone, // storage_class
ast::Access::kUndefined); // access
return builder_->create<sem::TypeConversion>(target, param);
});
if (!call_target) {
return nullptr;
}
auto val = EvaluateConstantValue(expr, target);
return builder_->create<sem::Call>(expr, call_target,
std::vector<const sem::Expression*>{arg},
current_statement_, val);
}
sem::Call* Resolver::TypeConstructor(
const ast::CallExpression* expr,
const sem::Type* ty,
const std::vector<const sem::Expression*> args,
const std::vector<const sem::Type*> arg_tys) {
// It is not valid to have a type-constructor call expression as a call
// statement.
if (IsCallStatement(expr)) {
AddError("type constructor evaluated but not used", expr->source);
return nullptr;
}
auto* call_target = utils::GetOrCreate(
type_ctors_, TypeConstructorSig{ty, arg_tys},
[&]() -> sem::TypeConstructor* {
// Now that the argument types have been determined, make sure that they
// obey the constructor type rules laid out in
// https://gpuweb.github.io/gpuweb/wgsl/#type-constructor-expr.
bool ok = true;
if (auto* vec_type = ty->As<sem::Vector>()) {
ok = ValidateVectorConstructorOrCast(expr, vec_type);
} else if (auto* mat_type = ty->As<sem::Matrix>()) {
ok = ValidateMatrixConstructorOrCast(expr, mat_type);
} else if (ty->is_scalar()) {
ok = ValidateScalarConstructorOrCast(expr, ty);
} else if (auto* arr_type = ty->As<sem::Array>()) {
ok = ValidateArrayConstructorOrCast(expr, arr_type);
} else if (auto* struct_type = ty->As<sem::Struct>()) {
ok = ValidateStructureConstructorOrCast(expr, struct_type);
} else {
AddError("type is not constructible", expr->source);
return nullptr;
}
if (!ok) {
return nullptr;
}
return builder_->create<sem::TypeConstructor>(
ty, utils::Transform(
arg_tys,
[&](const sem::Type* t, size_t i) -> const sem::Parameter* {
return builder_->create<sem::Parameter>(
nullptr, // declaration
i, // index
t->UnwrapRef(), // type
ast::StorageClass::kNone, // storage_class
ast::Access::kUndefined); // access
}));
});
if (!call_target) {
return nullptr;
}
auto val = EvaluateConstantValue(expr, ty);
return builder_->create<sem::Call>(expr, call_target, std::move(args),
current_statement_, val);
}
sem::Expression* Resolver::Literal(const ast::LiteralExpression* literal) {
auto* ty = TypeOf(literal);
if (!ty) {
return nullptr;
}
auto val = EvaluateConstantValue(literal, ty);
return builder_->create<sem::Expression>(literal, ty, current_statement_,
val);
}
sem::Expression* Resolver::Identifier(const ast::IdentifierExpression* expr) {
auto symbol = expr->symbol;
auto* resolved = ResolvedSymbol(expr);
if (auto* var = As<sem::Variable>(resolved)) {
auto* user =
builder_->create<sem::VariableUser>(expr, current_statement_, var);
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 = var->As<sem::GlobalVariable>()) {
current_function_->AddDirectlyReferencedGlobal(global);
}
}
var->AddUser(user);
return user;
}
if (Is<sem::Function>(resolved)) {
AddError("missing '(' for function call", expr->source.End());
return nullptr;
}
if (IsIntrinsic(symbol)) {
AddError("missing '(' for intrinsic 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 = TypeOf(expr->structure);
auto* storage_ty = structure->UnwrapRef();
const sem::Type* ret = nullptr;
std::vector<uint32_t> swizzle;
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());
}
return builder_->create<sem::StructMemberAccess>(
expr, ret, current_statement_, member);
}
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));
}
return builder_->create<sem::Swizzle>(expr, ret, current_statement_,
std::move(swizzle));
}
AddError(
"invalid member accessor expression. Expected vector or struct, got '" +
TypeNameOf(storage_ty) + "'",
expr->structure->source);
return nullptr;
}
sem::Expression* Resolver::Binary(const ast::BinaryExpression* expr) {
using Bool = sem::Bool;
using F32 = sem::F32;
using I32 = sem::I32;
using U32 = sem::U32;
using Matrix = sem::Matrix;
using Vector = sem::Vector;
auto* lhs = Sem(expr->lhs);
auto* rhs = Sem(expr->rhs);
auto* lhs_ty = lhs->Type()->UnwrapRef();
auto* rhs_ty = rhs->Type()->UnwrapRef();
auto* lhs_vec = lhs_ty->As<Vector>();
auto* lhs_vec_elem_type = lhs_vec ? lhs_vec->type() : nullptr;
auto* rhs_vec = rhs_ty->As<Vector>();
auto* rhs_vec_elem_type = rhs_vec ? rhs_vec->type() : nullptr;
const bool matching_vec_elem_types =
lhs_vec_elem_type && rhs_vec_elem_type &&
(lhs_vec_elem_type == rhs_vec_elem_type) &&
(lhs_vec->Width() == rhs_vec->Width());
const bool matching_types = matching_vec_elem_types || (lhs_ty == rhs_ty);
auto build = [&](const sem::Type* ty) {
auto val = EvaluateConstantValue(expr, ty);
auto* sem =
builder_->create<sem::Expression>(expr, ty, current_statement_, val);
sem->Behaviors() = lhs->Behaviors() + rhs->Behaviors();
return sem;
};
// Binary logical expressions
if (expr->IsLogicalAnd() || expr->IsLogicalOr()) {
if (matching_types && lhs_ty->Is<Bool>()) {
return build(lhs_ty);
}
}
if (expr->IsOr() || expr->IsAnd()) {
if (matching_types && lhs_ty->Is<Bool>()) {
return build(lhs_ty);
}
if (matching_types && lhs_vec_elem_type && lhs_vec_elem_type->Is<Bool>()) {
return build(lhs_ty);
}
}
// Arithmetic expressions
if (expr->IsArithmetic()) {
// Binary arithmetic expressions over scalars
if (matching_types && lhs_ty->is_numeric_scalar()) {
return build(lhs_ty);
}
// Binary arithmetic expressions over vectors
if (matching_types && lhs_vec_elem_type &&
lhs_vec_elem_type->is_numeric_scalar()) {
return build(lhs_ty);
}
// Binary arithmetic expressions with mixed scalar and vector operands
if (lhs_vec_elem_type && (lhs_vec_elem_type == rhs_ty)) {
if (expr->IsModulo()) {
if (rhs_ty->is_integer_scalar()) {
return build(lhs_ty);
}
} else if (rhs_ty->is_numeric_scalar()) {
return build(lhs_ty);
}
}
if (rhs_vec_elem_type && (rhs_vec_elem_type == lhs_ty)) {
if (expr->IsModulo()) {
if (lhs_ty->is_integer_scalar()) {
return build(rhs_ty);
}
} else if (lhs_ty->is_numeric_scalar()) {
return build(rhs_ty);
}
}
}
// Matrix arithmetic
auto* lhs_mat = lhs_ty->As<Matrix>();
auto* lhs_mat_elem_type = lhs_mat ? lhs_mat->type() : nullptr;
auto* rhs_mat = rhs_ty->As<Matrix>();
auto* rhs_mat_elem_type = rhs_mat ? rhs_mat->type() : nullptr;
// Addition and subtraction of float matrices
if ((expr->IsAdd() || expr->IsSubtract()) && lhs_mat_elem_type &&
lhs_mat_elem_type->Is<F32>() && rhs_mat_elem_type &&
rhs_mat_elem_type->Is<F32>() &&
(lhs_mat->columns() == rhs_mat->columns()) &&
(lhs_mat->rows() == rhs_mat->rows())) {
return build(rhs_ty);
}
if (expr->IsMultiply()) {
// Multiplication of a matrix and a scalar
if (lhs_ty->Is<F32>() && rhs_mat_elem_type &&
rhs_mat_elem_type->Is<F32>()) {
return build(rhs_ty);
}
if (lhs_mat_elem_type && lhs_mat_elem_type->Is<F32>() &&
rhs_ty->Is<F32>()) {
return build(lhs_ty);
}
// Vector times matrix
if (lhs_vec_elem_type && lhs_vec_elem_type->Is<F32>() &&
rhs_mat_elem_type && rhs_mat_elem_type->Is<F32>() &&
(lhs_vec->Width() == rhs_mat->rows())) {
return build(
builder_->create<sem::Vector>(lhs_vec->type(), rhs_mat->columns()));
}
// Matrix times vector
if (lhs_mat_elem_type && lhs_mat_elem_type->Is<F32>() &&
rhs_vec_elem_type && rhs_vec_elem_type->Is<F32>() &&
(lhs_mat->columns() == rhs_vec->Width())) {
return build(
builder_->create<sem::Vector>(rhs_vec->type(), lhs_mat->rows()));
}
// Matrix times matrix
if (lhs_mat_elem_type && lhs_mat_elem_type->Is<F32>() &&
rhs_mat_elem_type && rhs_mat_elem_type->Is<F32>() &&
(lhs_mat->columns() == rhs_mat->rows())) {
return build(builder_->create<sem::Matrix>(
builder_->create<sem::Vector>(lhs_mat_elem_type, lhs_mat->rows()),
rhs_mat->columns()));
}
}
// Comparison expressions
if (expr->IsComparison()) {
if (matching_types) {
// Special case for bools: only == and !=
if (lhs_ty->Is<Bool>() && (expr->IsEqual() || expr->IsNotEqual())) {
return build(builder_->create<sem::Bool>());
}
// For the rest, we can compare i32, u32, and f32
if (lhs_ty->IsAnyOf<I32, U32, F32>()) {
return build(builder_->create<sem::Bool>());
}
}
// Same for vectors
if (matching_vec_elem_types) {
if (lhs_vec_elem_type->Is<Bool>() &&
(expr->IsEqual() || expr->IsNotEqual())) {
return build(builder_->create<sem::Vector>(
builder_->create<sem::Bool>(), lhs_vec->Width()));
}
if (lhs_vec_elem_type->is_numeric_scalar()) {
return build(builder_->create<sem::Vector>(
builder_->create<sem::Bool>(), lhs_vec->Width()));
}
}
}
// Binary bitwise operations
if (expr->IsBitwise()) {
if (matching_types && lhs_ty->is_integer_scalar_or_vector()) {
return build(lhs_ty);
}
}
// Bit shift expressions
if (expr->IsBitshift()) {
// Type validation rules are the same for left or right shift, despite
// differences in computation rules (i.e. right shift can be arithmetic or
// logical depending on lhs type).
if (lhs_ty->IsAnyOf<I32, U32>() && rhs_ty->Is<U32>()) {
return build(lhs_ty);
}
if (lhs_vec_elem_type && lhs_vec_elem_type->IsAnyOf<I32, U32>() &&
rhs_vec_elem_type && rhs_vec_elem_type->Is<U32>()) {
return build(lhs_ty);
}
}
AddError("Binary expression operand types are invalid for this operation: " +
TypeNameOf(lhs_ty) + " " + FriendlyName(expr->op) + " " +
TypeNameOf(rhs_ty),
expr->source);
return nullptr;
}
sem::Expression* Resolver::UnaryOp(const ast::UnaryOpExpression* unary) {
auto* expr = Sem(unary->expr);
auto* expr_ty = expr->Type();
if (!expr_ty) {
return nullptr;
}
const sem::Type* ty = nullptr;
switch (unary->op) {
case ast::UnaryOp::kNot:
// Result type matches the deref'd inner type.
ty = expr_ty->UnwrapRef();
if (!ty->Is<sem::Bool>() && !ty->is_bool_vector()) {
AddError(
"cannot logical negate expression of type '" + TypeNameOf(expr_ty),
unary->expr->source);
return nullptr;
}
break;
case ast::UnaryOp::kComplement:
// Result type matches the deref'd inner type.
ty = expr_ty->UnwrapRef();
if (!ty->is_integer_scalar_or_vector()) {
AddError("cannot bitwise complement expression of type '" +
TypeNameOf(expr_ty),
unary->expr->source);
return nullptr;
}
break;
case ast::UnaryOp::kNegation:
// Result type matches the deref'd inner type.
ty = expr_ty->UnwrapRef();
if (!(ty->IsAnyOf<sem::F32, sem::I32>() ||
ty->is_signed_integer_vector() || ty->is_float_vector())) {
AddError("cannot negate expression of type '" + TypeNameOf(expr_ty),
unary->expr->source);
return nullptr;
}
break;
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 && TypeOf(array->object)->UnwrapRef()->Is<sem::Vector>()) ||
(member &&
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());
} 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());
} else {
AddError("cannot dereference expression of type '" +
TypeNameOf(expr_ty) + "'",
unary->expr->source);
return nullptr;
}
break;
}
auto val = EvaluateConstantValue(unary, ty);
auto* sem =
builder_->create<sem::Expression>(unary, ty, current_statement_, val);
sem->Behaviors() = expr->Behaviors();
return sem;
}
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::Type* Resolver::TypeOf(const ast::Expression* expr) {
auto* sem = Sem(expr);
return sem ? const_cast<sem::Type*>(sem->Type()) : nullptr;
}
std::string Resolver::TypeNameOf(const sem::Type* ty) {
return RawTypeNameOf(ty->UnwrapRef());
}
std::string Resolver::RawTypeNameOf(const sem::Type* ty) {
return ty->FriendlyName(builder_->Symbols());
}
sem::Type* Resolver::TypeOf(const ast::LiteralExpression* lit) {
if (lit->Is<ast::SintLiteralExpression>()) {
return builder_->create<sem::I32>();
}
if (lit->Is<ast::UintLiteralExpression>()) {
return builder_->create<sem::U32>();
}
if (lit->Is<ast::FloatLiteralExpression>()) {
return builder_->create<sem::F32>();
}
if (lit->Is<ast::BoolLiteralExpression>()) {
return builder_->create<sem::Bool>();
}
TINT_UNREACHABLE(Resolver, diagnostics_)
<< "Unhandled literal type: " << lit->TypeInfo().name;
return nullptr;
}
sem::Array* Resolver::Array(const ast::Array* arr) {
auto source = arr->source;
auto* elem_type = Type(arr->type);
if (!elem_type) {
return nullptr;
}
if (!IsPlain(elem_type)) { // Check must come before GetDefaultAlignAndSize()
AddError(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 (!ValidateNoDuplicateDecorations(arr->decorations)) {
return nullptr;
}
// Look for explicit stride via [[stride(n)]] decoration
uint32_t explicit_stride = 0;
for (auto* deco : arr->decorations) {
Mark(deco);
if (auto* sd = deco->As<ast::StrideDecoration>()) {
explicit_stride = sd->stride;
if (!ValidateArrayStrideDecoration(sd, el_size, el_align, source)) {
return nullptr;
}
continue;
}
AddError("decoration is not valid for array types", deco->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;
// Evaluate the constant array size expression.
// sem::Array uses a size of 0 for a runtime-sized array.
uint32_t count = 0;
if (auto* count_expr = arr->count) {
auto* count_sem = Expression(count_expr);
if (!count_sem) {
return nullptr;
}
auto size_source = count_expr->source;
auto* ty = count_sem->Type()->UnwrapRef();
if (!ty->is_integer_scalar()) {
AddError("array size must be integer scalar", size_source);
return nullptr;
}
if (auto* ident = count_expr->As<ast::IdentifierExpression>()) {
// Make sure the identifier is a non-overridable module-scope constant.
auto* var = ResolvedSymbol<sem::Variable>(ident);
if (!var || !var->Is<sem::GlobalVariable>() ||
!var->Declaration()->is_const) {
AddError("array size identifier must be a module-scope constant",
size_source);
return nullptr;
}
if (ast::HasDecoration<ast::OverrideDecoration>(
var->Declaration()->decorations)) {
AddError("array size expression must not be pipeline-overridable",
size_source);
return nullptr;
}
count_expr = var->Declaration()->constructor;
} else if (!count_expr->Is<ast::LiteralExpression>()) {
AddError(
"array size expression must be either a literal or a module-scope "
"constant",
size_source);
return nullptr;
}
auto count_val = count_sem->ConstantValue();
if (!count_val) {
TINT_ICE(Resolver, diagnostics_)
<< "could not resolve array size expression";
return nullptr;
}
if (ty->is_signed_integer_scalar() ? count_val.Elements()[0].i32 < 1
: count_val.Elements()[0].u32 < 1u) {
AddError("array size must be at least 1", size_source);
return nullptr;
}
count = count_val.Elements()[0].u32;
}
auto size = std::max<uint64_t>(count, 1) * stride;
if (size > std::numeric_limits<uint32_t>::max()) {
std::stringstream msg;
msg << "array size in bytes must not exceed 0x" << std::hex
<< std::numeric_limits<uint32_t>::max() << ", but is 0x" << std::hex
<< size;
AddError(msg.str(), arr->source);
return nullptr;
}
if (stride > std::numeric_limits<uint32_t>::max() ||
implicit_stride > std::numeric_limits<uint32_t>::max()) {
TINT_ICE(Resolver, diagnostics_)
<< "calculated array stride exceeds uint32";
return nullptr;
}
auto* out = builder_->create<sem::Array>(
elem_type, count, el_align, static_cast<uint32_t>(size),
static_cast<uint32_t>(stride), static_cast<uint32_t>(implicit_stride));
if (!ValidateArray(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 (!ValidateAlias(alias)) {
return nullptr;
}
return ty;
}
sem::Struct* Resolver::Structure(const ast::Struct* str) {
if (!ValidateNoDuplicateDecorations(str->decorations)) {
return nullptr;
}
for (auto* deco : str->decorations) {
Mark(deco);
}
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;
}
// Validate member type
if (!IsPlain(type)) {
AddError(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 (!ValidateNoDuplicateDecorations(member->decorations)) {
return nullptr;
}
bool has_offset_deco = false;
bool has_align_deco = false;
bool has_size_deco = false;
for (auto* deco : member->decorations) {
Mark(deco);
if (auto* o = deco->As<ast::StructMemberOffsetDecoration>()) {
// Offset decorations 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_deco = true;
} else if (auto* a = deco->As<ast::StructMemberAlignDecoration>()) {
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_deco = true;
} else if (auto* s = deco->As<ast::StructMemberSizeDecoration>()) {
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_deco = true;
}
}
if (has_offset_deco && (has_align_deco || has_size_deco)) {
AddError(
"offset decorations cannot be used with align or size decorations",
member->source);
return nullptr;
}
offset = utils::RoundUp(align, offset);
if (offset > std::numeric_limits<uint32_t>::max()) {
std::stringstream msg;
msg << "struct member has byte offset 0x" << std::hex << offset
<< ", but must not exceed 0x" << std::hex
<< std::numeric_limits<uint32_t>::max();
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 in bytes must not exceed 0x" << std::hex
<< std::numeric_limits<uint32_t>::max() << ", but is 0x" << std::hex
<< struct_size;
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;
}
}
}
if (!ValidateStructure(out)) {
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;
if (auto* value = stmt->value) {
auto* expr = Expression(value);
if (!expr) {
return false;
}
behaviors.Add(expr->Behaviors() - sem::Behavior::kNext);
}
// Validate after processing the return value expression so that its type is
// available for validation.
return ValidateReturn(stmt);
});
}
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();
auto* cond = Expression(stmt->condition);
if (!cond) {
return false;
}
behaviors = cond->Behaviors() - sem::Behavior::kNext;
for (auto* case_stmt : stmt->body) {
Mark(case_stmt);
auto* c = CaseStatement(case_stmt);
if (!c) {
return false;
}
behaviors.Add(c->Behaviors());
}
if (behaviors.Contains(sem::Behavior::kBreak)) {
behaviors.Add(sem::Behavior::kNext);
}
behaviors.Remove(sem::Behavior::kBreak, sem::Behavior::kFallthrough);
return ValidateSwitch(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* var = Variable(stmt->variable, VariableKind::kLocal);
if (!var) {
return false;
}
for (auto* deco : stmt->variable->decorations) {
Mark(deco);
if (!deco->Is<ast::InternalDecoration>()) {
AddError("decorations are not valid on local variables", deco->source);
return false;
}
}
if (current_block_) { // Not all statements are inside a block
current_block_->AddDecl(stmt->variable);
}
if (auto* ctor = var->Constructor()) {
sem->Behaviors() = ctor->Behaviors();
}
return ValidateVariable(var);
});
}
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;
}
auto* rhs = Expression(stmt->rhs);
if (!rhs) {
return false;
}
auto& behaviors = sem->Behaviors();
behaviors = rhs->Behaviors();
if (!stmt->lhs->Is<ast::PhonyExpression>()) {
behaviors.Add(lhs->Behaviors());
}
return ValidateAssignment(stmt);
});
}
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 ValidateBreakStatement(sem);
});
}
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::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 ValidateContinueStatement(sem);
});
}
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 ValidateDiscardStatement(sem);
});
}
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 ValidateFallthroughStatement(sem);
});
}
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 " << 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>()) {
return ApplyStorageClassUsageToType(
sc, const_cast<sem::Type*>(arr->ElemType()), usage);
}
if (ast::IsHostShareable(sc) && !IsHostShareable(ty)) {
std::stringstream err;
err << "Type '" << 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;
}
std::string Resolver::VectorPretty(uint32_t size,
const sem::Type* element_type) {
sem::Vector vec_type(element_type, size);
return vec_type.FriendlyName(builder_->Symbols());
}
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);
}
// https://gpuweb.github.io/gpuweb/wgsl/#plain-types-section
bool Resolver::IsPlain(const sem::Type* type) const {
return type->is_scalar() ||
type->IsAnyOf<sem::Atomic, sem::Vector, sem::Matrix, sem::Array,
sem::Struct>();
}
// https://gpuweb.github.io/gpuweb/wgsl.html#storable-types
bool Resolver::IsStorable(const sem::Type* type) const {
return IsPlain(type) || type->IsAnyOf<sem::Texture, sem::Sampler>();
}
// https://gpuweb.github.io/gpuweb/wgsl.html#host-shareable-types
bool Resolver::IsHostShareable(const sem::Type* type) const {
if (type->IsAnyOf<sem::I32, sem::U32, sem::F32>()) {
return true;
}
if (auto* vec = type->As<sem::Vector>()) {
return IsHostShareable(vec->type());
}
if (auto* mat = type->As<sem::Matrix>()) {
return IsHostShareable(mat->type());
}
if (auto* arr = type->As<sem::Array>()) {
return IsHostShareable(arr->ElemType());
}
if (auto* str = type->As<sem::Struct>()) {
for (auto* member : str->Members()) {
if (!IsHostShareable(member->Type())) {
return false;
}
}
return true;
}
if (auto* atomic = type->As<sem::Atomic>()) {
return IsHostShareable(atomic->Type());
}
return false;
}
bool Resolver::IsIntrinsic(Symbol symbol) const {
std::string name = builder_->Symbols().NameFor(symbol);
return sem::ParseIntrinsicType(name) != sem::IntrinsicType::kNone;
}
bool Resolver::IsCallStatement(const ast::Expression* expr) const {
return current_statement_ &&
Is<ast::CallStatement>(current_statement_->Declaration(),
[&](auto* stmt) { return stmt->expr == expr; });
}
const ast::Statement* Resolver::ClosestContinuing(bool stop_at_loop) const {
for (const auto* s = current_statement_; s != nullptr; s = s->Parent()) {
if (stop_at_loop && s->Is<sem::LoopStatement>()) {
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;
}
}
}
return nullptr;
}
////////////////////////////////////////////////////////////////////////////////
// Resolver::TypeConversionSig
////////////////////////////////////////////////////////////////////////////////
bool Resolver::TypeConversionSig::operator==(
const TypeConversionSig& rhs) const {
return target == rhs.target && source == rhs.source;
}
std::size_t Resolver::TypeConversionSig::Hasher::operator()(
const TypeConversionSig& sig) const {
return utils::Hash(sig.target, sig.source);
}
////////////////////////////////////////////////////////////////////////////////
// Resolver::TypeConstructorSig
////////////////////////////////////////////////////////////////////////////////
Resolver::TypeConstructorSig::TypeConstructorSig(
const sem::Type* ty,
const std::vector<const sem::Type*> params)
: type(ty), parameters(params) {}
Resolver::TypeConstructorSig::TypeConstructorSig(const TypeConstructorSig&) =
default;
Resolver::TypeConstructorSig::~TypeConstructorSig() = default;
bool Resolver::TypeConstructorSig::operator==(
const TypeConstructorSig& rhs) const {
return type == rhs.type && parameters == rhs.parameters;
}
std::size_t Resolver::TypeConstructorSig::Hasher::operator()(
const TypeConstructorSig& sig) const {
return utils::Hash(sig.type, sig.parameters);
}
} // namespace resolver
} // namespace tint