| // 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/add_block_attribute.h" |
| |
| #include <unordered_set> |
| #include <utility> |
| |
| #include "src/tint/program_builder.h" |
| #include "src/tint/sem/variable.h" |
| #include "src/tint/utils/hashmap.h" |
| #include "src/tint/utils/hashset.h" |
| |
| TINT_INSTANTIATE_TYPEINFO(tint::transform::AddBlockAttribute); |
| TINT_INSTANTIATE_TYPEINFO(tint::transform::AddBlockAttribute::BlockAttribute); |
| |
| namespace tint::transform { |
| |
| AddBlockAttribute::AddBlockAttribute() = default; |
| |
| AddBlockAttribute::~AddBlockAttribute() = default; |
| |
| Transform::ApplyResult AddBlockAttribute::Apply(const Program* src, |
| const DataMap&, |
| DataMap&) const { |
| ProgramBuilder b; |
| CloneContext ctx{&b, src, /* auto_clone_symbols */ true}; |
| |
| auto& sem = src->Sem(); |
| |
| // A map from a type in the source program to a block-decorated wrapper that contains it in the |
| // destination program. |
| utils::Hashmap<const type::Type*, const ast::Struct*, 8> wrapper_structs; |
| |
| // Process global 'var' declarations that are buffers. |
| bool made_changes = false; |
| for (auto* global : src->AST().GlobalVariables()) { |
| auto* var = sem.Get(global); |
| if (!builtin::IsHostShareable(var->AddressSpace())) { |
| // Not declared in a host-sharable address space |
| continue; |
| } |
| |
| made_changes = true; |
| |
| auto* ty = var->Type()->UnwrapRef(); |
| auto* str = ty->As<sem::Struct>(); |
| |
| // Always try to wrap the buffer type into a struct. We can not do so only if it is a struct |
| // but without a fixed footprint, i.e. contains a runtime-sized array as its member. Note |
| // that such struct type can be only used as storage buffer variables' type. Also note that |
| // any buffer struct type that may be nested by another type must have a fixed footprint, |
| // therefore will be wrapped. |
| bool needs_wrapping = !str || // Type is not a structure |
| str->HasFixedFootprint(); // Struct has a fixed footprint |
| |
| if (needs_wrapping) { |
| const char* kMemberName = "inner"; |
| |
| auto* wrapper = wrapper_structs.GetOrCreate(ty, [&] { |
| auto* block = b.ASTNodes().Create<BlockAttribute>(b.ID(), b.AllocateNodeID()); |
| auto wrapper_name = src->Symbols().NameFor(global->name->symbol) + "_block"; |
| auto* ret = b.create<ast::Struct>( |
| b.Ident(b.Symbols().New(wrapper_name)), |
| utils::Vector{b.Member(kMemberName, CreateASTTypeFor(ctx, ty))}, |
| utils::Vector{block}); |
| ctx.InsertBefore(src->AST().GlobalDeclarations(), global, ret); |
| return ret; |
| }); |
| ctx.Replace(global->type.expr, b.Expr(wrapper->name->symbol)); |
| |
| // Insert a member accessor to get the original type from the wrapper at |
| // any usage of the original variable. |
| for (auto* user : var->Users()) { |
| ctx.Replace(user->Declaration(), |
| b.MemberAccessor(ctx.Clone(global->name->symbol), kMemberName)); |
| } |
| } else { |
| // Add a block attribute to this struct directly. |
| auto* block = b.ASTNodes().Create<BlockAttribute>(b.ID(), b.AllocateNodeID()); |
| ctx.InsertFront(str->Declaration()->attributes, block); |
| } |
| } |
| |
| if (!made_changes) { |
| return SkipTransform; |
| } |
| |
| ctx.Clone(); |
| return Program(std::move(b)); |
| } |
| |
| AddBlockAttribute::BlockAttribute::BlockAttribute(ProgramID pid, ast::NodeID nid) |
| : Base(pid, nid, utils::Empty) {} |
| AddBlockAttribute::BlockAttribute::~BlockAttribute() = default; |
| std::string AddBlockAttribute::BlockAttribute::InternalName() const { |
| return "block"; |
| } |
| |
| const AddBlockAttribute::BlockAttribute* AddBlockAttribute::BlockAttribute::Clone( |
| CloneContext* ctx) const { |
| return ctx->dst->ASTNodes().Create<AddBlockAttribute::BlockAttribute>( |
| ctx->dst->ID(), ctx->dst->AllocateNodeID()); |
| } |
| |
| } // namespace tint::transform |