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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/validator/validator_impl.h"
#include <cassert>
#include <unordered_set>
#include "src/ast/call_statement.h"
#include "src/ast/function.h"
#include "src/ast/int_literal.h"
#include "src/ast/intrinsic.h"
#include "src/ast/sint_literal.h"
#include "src/ast/struct.h"
#include "src/ast/switch_statement.h"
#include "src/ast/type/array_type.h"
#include "src/ast/type/i32_type.h"
#include "src/ast/type/struct_type.h"
#include "src/ast/type/u32_type.h"
#include "src/ast/type/void_type.h"
#include "src/ast/uint_literal.h"
#include "src/ast/variable_decl_statement.h"
namespace tint {
ValidatorImpl::ValidatorImpl() = default;
ValidatorImpl::~ValidatorImpl() = default;
void ValidatorImpl::set_error(const Source& src, const std::string& msg) {
error_ += std::to_string(src.range.begin.line) + ":" +
std::to_string(src.range.begin.column) + ": " + msg;
}
bool ValidatorImpl::Validate(const ast::Module* module) {
if (!module) {
return false;
}
function_stack_.push_scope();
if (!ValidateGlobalVariables(module->global_variables())) {
return false;
}
if (!ValidateConstructedTypes(module->constructed_types())) {
return false;
}
if (!ValidateFunctions(module->functions())) {
return false;
}
if (!ValidateEntryPoint(module->functions())) {
return false;
}
function_stack_.pop_scope();
return true;
}
bool ValidatorImpl::ValidateConstructedTypes(
const std::vector<ast::type::Type*>& constructed_types) {
for (auto* const ct : constructed_types) {
if (ct->IsStruct()) {
auto* st = ct->AsStruct();
for (auto* member : st->impl()->members()) {
if (member->type()->UnwrapAll()->IsArray()) {
auto* r = member->type()->UnwrapAll()->AsArray();
if (r->IsRuntimeArray() && member != st->impl()->members().back()) {
set_error(member->source(),
"v-0015: runtime arrays may only appear as the last "
"member of a struct: '" +
member->name() + "'");
return false;
}
}
}
}
}
return true;
}
bool ValidatorImpl::ValidateGlobalVariables(
const ast::VariableList& global_vars) {
for (auto* var : global_vars) {
if (variable_stack_.has(var->name())) {
set_error(var->source(),
"v-0011: redeclared global identifier '" + var->name() + "'");
return false;
}
if (!var->is_const() && var->storage_class() == ast::StorageClass::kNone) {
set_error(var->source(),
"v-0022: global variables must have a storage class");
return false;
}
if (var->is_const() &&
!(var->storage_class() == ast::StorageClass::kNone)) {
set_error(var->source(),
"v-global01: global constants shouldn't have a storage class");
return false;
}
variable_stack_.set_global(var->name(), var);
}
return true;
}
bool ValidatorImpl::ValidateFunctions(const ast::FunctionList& funcs) {
for (auto* func : funcs) {
if (function_stack_.has(func->name())) {
set_error(func->source(),
"v-0016: function names must be unique '" + func->name() + "'");
return false;
}
function_stack_.set(func->name(), func);
current_function_ = func;
if (!ValidateFunction(func)) {
return false;
}
current_function_ = nullptr;
}
return true;
}
bool ValidatorImpl::ValidateEntryPoint(const ast::FunctionList& funcs) {
auto shader_is_present = false;
for (auto* func : funcs) {
if (func->IsEntryPoint()) {
shader_is_present = true;
if (!func->params().empty()) {
set_error(func->source(),
"v-0023: Entry point function must accept no parameters: '" +
func->name() + "'");
return false;
}
if (!func->return_type()->IsVoid()) {
set_error(func->source(),
"v-0024: Entry point function must return void: '" +
func->name() + "'");
return false;
}
auto stage_deco_count = 0;
for (auto* deco : func->decorations()) {
if (deco->IsStage()) {
stage_deco_count++;
}
}
if (stage_deco_count > 1) {
set_error(
func->source(),
"v-0020: only one stage decoration permitted per entry point");
return false;
}
}
}
if (!shader_is_present) {
set_error(Source{},
"v-0003: At least one of vertex, fragment or compute shader must "
"be present");
return false;
}
return true;
}
bool ValidatorImpl::ValidateFunction(const ast::Function* func) {
variable_stack_.push_scope();
for (auto* param : func->params()) {
variable_stack_.set(param->name(), param);
}
if (!ValidateStatements(func->body())) {
return false;
}
variable_stack_.pop_scope();
if (!current_function_->return_type()->IsVoid()) {
if (!func->get_last_statement() ||
!func->get_last_statement()->IsReturn()) {
set_error(func->source(),
"v-0002: non-void function must end with a return statement");
return false;
}
}
return true;
}
bool ValidatorImpl::ValidateReturnStatement(const ast::ReturnStatement* ret) {
// TODO(sarahM0): update this when this issue resolves:
// https://github.com/gpuweb/gpuweb/issues/996
ast::type::Type* func_type = current_function_->return_type();
ast::type::VoidType void_type;
auto* ret_type =
ret->has_value() ? ret->value()->result_type()->UnwrapAll() : &void_type;
if (func_type->type_name() != ret_type->type_name()) {
set_error(ret->source(),
"v-000y: return statement type must match its function return "
"type, returned '" +
ret_type->type_name() + "', expected '" +
func_type->type_name() + "'");
return false;
}
return true;
}
bool ValidatorImpl::ValidateStatements(const ast::BlockStatement* block) {
if (!block) {
return false;
}
for (auto* stmt : *block) {
if (!ValidateStatement(stmt)) {
return false;
}
}
return true;
}
bool ValidatorImpl::ValidateDeclStatement(
const ast::VariableDeclStatement* decl) {
auto name = decl->variable()->name();
bool is_global = false;
if (variable_stack_.get(name, nullptr, &is_global)) {
std::string error_number = "v-0014: ";
if (is_global) {
error_number = "v-0013: ";
}
set_error(decl->source(),
error_number + "redeclared identifier '" + name + "'");
return false;
}
variable_stack_.set(name, decl->variable());
if (decl->variable()->type()->UnwrapAll()->IsArray()) {
if (decl->variable()->type()->UnwrapAll()->AsArray()->IsRuntimeArray()) {
set_error(decl->source(),
"v-0015: runtime arrays may only appear as the last "
"member of a struct: '" +
decl->variable()->name() + "'");
return false;
}
}
return true;
}
bool ValidatorImpl::ValidateStatement(const ast::Statement* stmt) {
if (!stmt) {
return false;
}
if (stmt->IsVariableDecl()) {
auto* v = stmt->AsVariableDecl();
bool constructor_valid =
v->variable()->has_constructor()
? ValidateExpression(v->variable()->constructor())
: true;
return constructor_valid && ValidateDeclStatement(stmt->AsVariableDecl());
}
if (stmt->IsAssign()) {
return ValidateAssign(stmt->AsAssign());
}
if (stmt->IsReturn()) {
return ValidateReturnStatement(stmt->AsReturn());
}
if (stmt->IsCall()) {
return ValidateCallExpr(stmt->AsCall()->expr());
}
if (stmt->IsSwitch()) {
return ValidateSwitch(stmt->AsSwitch());
}
if (stmt->IsCase()) {
return ValidateCase(stmt->AsCase());
}
return true;
}
bool ValidatorImpl::ValidateSwitch(const ast::SwitchStatement* s) {
if (!ValidateExpression(s->condition())) {
return false;
}
auto* cond_type = s->condition()->result_type()->UnwrapAll();
if (!(cond_type->IsI32() || cond_type->IsU32())) {
set_error(s->condition()->source(),
"v-0025: switch statement selector expression must be of a "
"scalar integer type");
return false;
}
int default_counter = 0;
std::unordered_set<int32_t> selector_set;
for (auto* case_stmt : s->body()) {
if (!ValidateStatement(case_stmt)) {
return false;
}
if (case_stmt->IsDefault()) {
default_counter++;
}
for (auto* selector : case_stmt->selectors()) {
if (cond_type != selector->type()) {
set_error(case_stmt->source(),
"v-0026: the case selector values must have the same "
"type as the selector expression.");
return false;
}
auto v = static_cast<int32_t>(selector->type()->IsU32()
? selector->AsUint()->value()
: selector->AsSint()->value());
if (selector_set.count(v)) {
auto v_str = selector->type()->IsU32() ? selector->AsUint()->to_str()
: selector->AsSint()->to_str();
set_error(case_stmt->source(),
"v-0027: a literal value must not appear more than once in "
"the case selectors for a switch statement: '" +
v_str + "'");
return false;
}
selector_set.emplace(v);
}
}
if (default_counter != 1) {
set_error(s->source(),
"v-0008: switch statement must have exactly one default clause");
return false;
}
auto* last_clause = s->body().back();
auto* last_stmt_of_last_clause = last_clause->AsCase()->body()->last();
if (last_stmt_of_last_clause && last_stmt_of_last_clause->IsFallthrough()) {
set_error(last_stmt_of_last_clause->source(),
"v-0028: a fallthrough statement must not appear as "
"the last statement in last clause of a switch");
return false;
}
return true;
}
bool ValidatorImpl::ValidateCase(const ast::CaseStatement* c) {
if (!ValidateStatement(c->body())) {
return false;
}
return true;
}
bool ValidatorImpl::ValidateCallExpr(const ast::CallExpression* expr) {
if (!expr) {
// TODO(sarahM0): Here and other Validate.*: figure out whether return
// false or true
return false;
}
if (expr->func()->IsIdentifier()) {
auto* ident = expr->func()->AsIdentifier();
auto func_name = ident->name();
if (ident->IsIntrinsic()) {
// TODO(sarahM0): validate intrinsics - tied with type-determiner
} else {
if (!function_stack_.has(func_name)) {
set_error(expr->source(),
"v-0005: function must be declared before use: '" +
func_name + "'");
return false;
}
if (func_name == current_function_->name()) {
set_error(expr->source(),
"v-0004: recursion is not allowed: '" + func_name + "'");
return false;
}
}
} else {
set_error(expr->source(), "Invalid function call expression");
return false;
}
return true;
}
bool ValidatorImpl::ValidateAssign(const ast::AssignmentStatement* a) {
if (!a) {
return false;
}
if (!(ValidateConstant(a))) {
return false;
}
if (!(ValidateExpression(a->lhs()) && ValidateExpression(a->rhs()))) {
return false;
}
if (!ValidateResultTypes(a)) {
return false;
}
return true;
}
bool ValidatorImpl::ValidateConstant(const ast::AssignmentStatement* assign) {
if (!assign) {
return false;
}
if (assign->lhs()->IsIdentifier()) {
ast::Variable* var;
auto* ident = assign->lhs()->AsIdentifier();
if (variable_stack_.get(ident->name(), &var)) {
if (var->is_const()) {
set_error(assign->source(), "v-0021: cannot re-assign a constant: '" +
ident->name() + "'");
return false;
}
}
}
return true;
}
bool ValidatorImpl::ValidateResultTypes(const ast::AssignmentStatement* a) {
if (!a->lhs()->result_type() || !a->rhs()->result_type()) {
set_error(a->source(), "result_type() is nullptr");
return false;
}
auto* lhs_result_type = a->lhs()->result_type()->UnwrapAll();
auto* rhs_result_type = a->rhs()->result_type()->UnwrapAll();
if (lhs_result_type != rhs_result_type) {
// TODO(sarahM0): figur out what should be the error number.
set_error(a->source(), "v-000x: invalid assignment of '" +
lhs_result_type->type_name() + "' to '" +
rhs_result_type->type_name() + "'");
return false;
}
return true;
}
bool ValidatorImpl::ValidateExpression(const ast::Expression* expr) {
if (!expr) {
return false;
}
if (expr->IsIdentifier()) {
return ValidateIdentifier(expr->AsIdentifier());
}
if (expr->IsCall()) {
return ValidateCallExpr(expr->AsCall());
}
return true;
}
bool ValidatorImpl::ValidateIdentifier(const ast::IdentifierExpression* ident) {
ast::Variable* var;
if (!variable_stack_.get(ident->name(), &var)) {
set_error(ident->source(),
"v-0006: '" + ident->name() + "' is not declared");
return false;
}
return true;
}
} // namespace tint