| // Copyright 2021 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/transform/single_entry_point.h" |
| |
| #include <unordered_set> |
| #include <utility> |
| |
| #include "src/tint/program_builder.h" |
| #include "src/tint/sem/function.h" |
| #include "src/tint/sem/variable.h" |
| |
| TINT_INSTANTIATE_TYPEINFO(tint::transform::SingleEntryPoint); |
| TINT_INSTANTIATE_TYPEINFO(tint::transform::SingleEntryPoint::Config); |
| |
| namespace tint::transform { |
| |
| SingleEntryPoint::SingleEntryPoint() = default; |
| |
| SingleEntryPoint::~SingleEntryPoint() = default; |
| |
| Transform::ApplyResult SingleEntryPoint::Apply(const Program* src, |
| const DataMap& inputs, |
| DataMap&) const { |
| ProgramBuilder b; |
| CloneContext ctx{&b, src, /* auto_clone_symbols */ true}; |
| |
| auto* cfg = inputs.Get<Config>(); |
| if (cfg == nullptr) { |
| b.Diagnostics().add_error(diag::System::Transform, |
| "missing transform data for " + std::string(TypeInfo().name)); |
| return Program(std::move(b)); |
| } |
| |
| // Find the target entry point. |
| const ast::Function* entry_point = nullptr; |
| for (auto* f : src->AST().Functions()) { |
| if (!f->IsEntryPoint()) { |
| continue; |
| } |
| if (src->Symbols().NameFor(f->symbol) == cfg->entry_point_name) { |
| entry_point = f; |
| break; |
| } |
| } |
| if (entry_point == nullptr) { |
| b.Diagnostics().add_error(diag::System::Transform, |
| "entry point '" + cfg->entry_point_name + "' not found"); |
| return Program(std::move(b)); |
| } |
| |
| auto& sem = src->Sem(); |
| |
| // Build set of referenced module-scope variables for faster lookups later. |
| std::unordered_set<const ast::Variable*> referenced_vars; |
| for (auto* var : sem.Get(entry_point)->TransitivelyReferencedGlobals()) { |
| referenced_vars.emplace(var->Declaration()); |
| } |
| |
| // Clone any module-scope variables, types, and functions that are statically referenced by the |
| // target entry point. |
| for (auto* decl : src->AST().GlobalDeclarations()) { |
| Switch( |
| decl, // |
| [&](const ast::TypeDecl* ty) { |
| // TODO(jrprice): Strip unused types. |
| b.AST().AddTypeDecl(ctx.Clone(ty)); |
| }, |
| [&](const ast::Override* override) { |
| if (referenced_vars.count(override)) { |
| if (!ast::HasAttribute<ast::IdAttribute>(override->attributes)) { |
| // If the override doesn't already have an @id() attribute, add one |
| // so that its allocated ID so that it won't be affected by other |
| // stripped away overrides |
| auto* global = sem.Get(override); |
| const auto* id = b.Id(global->OverrideId()); |
| ctx.InsertFront(override->attributes, id); |
| } |
| b.AST().AddGlobalVariable(ctx.Clone(override)); |
| } |
| }, |
| [&](const ast::Var* var) { |
| if (referenced_vars.count(var)) { |
| b.AST().AddGlobalVariable(ctx.Clone(var)); |
| } |
| }, |
| [&](const ast::Const* c) { |
| // Always keep 'const' declarations, as these can be used by attributes and array |
| // sizes, which are not tracked as transitively used by functions. They also don't |
| // typically get emitted by the backend unless they're actually used. |
| b.AST().AddGlobalVariable(ctx.Clone(c)); |
| }, |
| [&](const ast::Function* func) { |
| if (sem.Get(func)->HasAncestorEntryPoint(entry_point->symbol)) { |
| b.AST().AddFunction(ctx.Clone(func)); |
| } |
| }, |
| [&](const ast::Enable* ext) { b.AST().AddEnable(ctx.Clone(ext)); }, |
| [&](Default) { |
| TINT_UNREACHABLE(Transform, b.Diagnostics()) |
| << "unhandled global declaration: " << decl->TypeInfo().name; |
| }); |
| } |
| |
| // Clone the entry point. |
| b.AST().AddFunction(ctx.Clone(entry_point)); |
| |
| return Program(std::move(b)); |
| } |
| |
| SingleEntryPoint::Config::Config(std::string entry_point) : entry_point_name(entry_point) {} |
| |
| SingleEntryPoint::Config::Config(const Config&) = default; |
| SingleEntryPoint::Config::~Config() = default; |
| SingleEntryPoint::Config& SingleEntryPoint::Config::operator=(const Config&) = default; |
| |
| } // namespace tint::transform |