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// 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/writer/wgsl/generator_impl.h"
#include <algorithm>
#include "src/tint/ast/access.h"
#include "src/tint/ast/alias.h"
#include "src/tint/ast/array.h"
#include "src/tint/ast/atomic.h"
#include "src/tint/ast/bool.h"
#include "src/tint/ast/bool_literal_expression.h"
#include "src/tint/ast/call_statement.h"
#include "src/tint/ast/depth_texture.h"
#include "src/tint/ast/external_texture.h"
#include "src/tint/ast/f32.h"
#include "src/tint/ast/float_literal_expression.h"
#include "src/tint/ast/i32.h"
#include "src/tint/ast/id_attribute.h"
#include "src/tint/ast/internal_attribute.h"
#include "src/tint/ast/interpolate_attribute.h"
#include "src/tint/ast/invariant_attribute.h"
#include "src/tint/ast/matrix.h"
#include "src/tint/ast/module.h"
#include "src/tint/ast/multisampled_texture.h"
#include "src/tint/ast/pointer.h"
#include "src/tint/ast/sampled_texture.h"
#include "src/tint/ast/stage_attribute.h"
#include "src/tint/ast/storage_texture.h"
#include "src/tint/ast/stride_attribute.h"
#include "src/tint/ast/struct_member_align_attribute.h"
#include "src/tint/ast/struct_member_offset_attribute.h"
#include "src/tint/ast/struct_member_size_attribute.h"
#include "src/tint/ast/type_name.h"
#include "src/tint/ast/u32.h"
#include "src/tint/ast/variable_decl_statement.h"
#include "src/tint/ast/vector.h"
#include "src/tint/ast/void.h"
#include "src/tint/ast/workgroup_attribute.h"
#include "src/tint/sem/struct.h"
#include "src/tint/utils/math.h"
#include "src/tint/utils/scoped_assignment.h"
#include "src/tint/writer/float_to_string.h"
namespace tint::writer::wgsl {
GeneratorImpl::GeneratorImpl(const Program* program) : TextGenerator(program) {}
GeneratorImpl::~GeneratorImpl() = default;
bool GeneratorImpl::Generate() {
// Generate enable directives before any other global declarations.
for (auto enable : program_->AST().Enables()) {
if (!EmitEnable(enable)) {
return false;
}
}
if (!program_->AST().Enables().empty()) {
line();
}
// Generate global declarations in the order they appear in the module.
for (auto* decl : program_->AST().GlobalDeclarations()) {
if (decl->Is<ast::Enable>()) {
continue;
}
if (!Switch(
decl, //
[&](const ast::TypeDecl* td) { return EmitTypeDecl(td); },
[&](const ast::Function* func) { return EmitFunction(func); },
[&](const ast::Variable* var) { return EmitVariable(line(), var); },
[&](Default) {
TINT_UNREACHABLE(Writer, diagnostics_);
return false;
})) {
return false;
}
if (decl != program_->AST().GlobalDeclarations().back()) {
line();
}
}
return true;
}
bool GeneratorImpl::EmitEnable(const ast::Enable* enable) {
auto out = line();
out << "enable " << enable->extension << ";";
return true;
}
bool GeneratorImpl::EmitTypeDecl(const ast::TypeDecl* ty) {
return Switch(
ty,
[&](const ast::Alias* alias) { //
auto out = line();
out << "type " << program_->Symbols().NameFor(alias->name) << " = ";
if (!EmitType(out, alias->type)) {
return false;
}
out << ";";
return true;
},
[&](const ast::Struct* str) { //
return EmitStructType(str);
},
[&](Default) { //
diagnostics_.add_error(diag::System::Writer,
"unknown declared type: " + std::string(ty->TypeInfo().name));
return false;
});
}
bool GeneratorImpl::EmitExpression(std::ostream& out, const ast::Expression* expr) {
return Switch(
expr,
[&](const ast::IndexAccessorExpression* a) { //
return EmitIndexAccessor(out, a);
},
[&](const ast::BinaryExpression* b) { //
return EmitBinary(out, b);
},
[&](const ast::BitcastExpression* b) { //
return EmitBitcast(out, b);
},
[&](const ast::CallExpression* c) { //
return EmitCall(out, c);
},
[&](const ast::IdentifierExpression* i) { //
return EmitIdentifier(out, i);
},
[&](const ast::LiteralExpression* l) { //
return EmitLiteral(out, l);
},
[&](const ast::MemberAccessorExpression* m) { //
return EmitMemberAccessor(out, m);
},
[&](const ast::PhonyExpression*) { //
out << "_";
return true;
},
[&](const ast::UnaryOpExpression* u) { //
return EmitUnaryOp(out, u);
},
[&](Default) {
diagnostics_.add_error(diag::System::Writer, "unknown expression type");
return false;
});
}
bool GeneratorImpl::EmitIndexAccessor(std::ostream& out, const ast::IndexAccessorExpression* expr) {
bool paren_lhs =
!expr->object->IsAnyOf<ast::IndexAccessorExpression, ast::CallExpression,
ast::IdentifierExpression, ast::MemberAccessorExpression>();
if (paren_lhs) {
out << "(";
}
if (!EmitExpression(out, expr->object)) {
return false;
}
if (paren_lhs) {
out << ")";
}
out << "[";
if (!EmitExpression(out, expr->index)) {
return false;
}
out << "]";
return true;
}
bool GeneratorImpl::EmitMemberAccessor(std::ostream& out,
const ast::MemberAccessorExpression* expr) {
bool paren_lhs =
!expr->structure->IsAnyOf<ast::IndexAccessorExpression, ast::CallExpression,
ast::IdentifierExpression, ast::MemberAccessorExpression>();
if (paren_lhs) {
out << "(";
}
if (!EmitExpression(out, expr->structure)) {
return false;
}
if (paren_lhs) {
out << ")";
}
out << ".";
return EmitExpression(out, expr->member);
}
bool GeneratorImpl::EmitBitcast(std::ostream& out, const ast::BitcastExpression* expr) {
out << "bitcast<";
if (!EmitType(out, expr->type)) {
return false;
}
out << ">(";
if (!EmitExpression(out, expr->expr)) {
return false;
}
out << ")";
return true;
}
bool GeneratorImpl::EmitCall(std::ostream& out, const ast::CallExpression* expr) {
if (expr->target.name) {
if (!EmitExpression(out, expr->target.name)) {
return false;
}
} else if (expr->target.type) {
if (!EmitType(out, expr->target.type)) {
return false;
}
} else {
TINT_ICE(Writer, diagnostics_) << "CallExpression target had neither a name or type";
return false;
}
out << "(";
bool first = true;
const auto& args = expr->args;
for (auto* arg : args) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitExpression(out, arg)) {
return false;
}
}
out << ")";
return true;
}
bool GeneratorImpl::EmitLiteral(std::ostream& out, const ast::LiteralExpression* lit) {
return Switch(
lit,
[&](const ast::BoolLiteralExpression* l) { //
out << (l->value ? "true" : "false");
return true;
},
[&](const ast::FloatLiteralExpression* l) { //
// f16 literals are also emitted as float value with suffix "h".
// Note that all normal and subnormal f16 values are normal f32 values, and since NaN
// and Inf are not allowed to be spelled in literal, it should be fine to emit f16
// literals in this way.
out << FloatToBitPreservingString(static_cast<float>(l->value)) << l->suffix;
return true;
},
[&](const ast::IntLiteralExpression* l) { //
out << l->value << l->suffix;
return true;
},
[&](Default) { //
diagnostics_.add_error(diag::System::Writer, "unknown literal type");
return false;
});
}
bool GeneratorImpl::EmitIdentifier(std::ostream& out, const ast::IdentifierExpression* expr) {
out << program_->Symbols().NameFor(expr->symbol);
return true;
}
bool GeneratorImpl::EmitFunction(const ast::Function* func) {
if (func->attributes.size()) {
if (!EmitAttributes(line(), func->attributes)) {
return false;
}
}
{
auto out = line();
out << "fn " << program_->Symbols().NameFor(func->symbol) << "(";
bool first = true;
for (auto* v : func->params) {
if (!first) {
out << ", ";
}
first = false;
if (!v->attributes.empty()) {
if (!EmitAttributes(out, v->attributes)) {
return false;
}
out << " ";
}
out << program_->Symbols().NameFor(v->symbol) << " : ";
if (!EmitType(out, v->type)) {
return false;
}
}
out << ")";
if (!func->return_type->Is<ast::Void>() || !func->return_type_attributes.empty()) {
out << " -> ";
if (!func->return_type_attributes.empty()) {
if (!EmitAttributes(out, func->return_type_attributes)) {
return false;
}
out << " ";
}
if (!EmitType(out, func->return_type)) {
return false;
}
}
if (func->body) {
out << " {";
}
}
if (func->body) {
if (!EmitStatementsWithIndent(func->body->statements)) {
return false;
}
line() << "}";
}
return true;
}
bool GeneratorImpl::EmitImageFormat(std::ostream& out, const ast::TexelFormat fmt) {
switch (fmt) {
case ast::TexelFormat::kInvalid:
diagnostics_.add_error(diag::System::Writer, "unknown image format");
return false;
default:
out << fmt;
}
return true;
}
bool GeneratorImpl::EmitAccess(std::ostream& out, const ast::Access access) {
switch (access) {
case ast::Access::kRead:
out << "read";
return true;
case ast::Access::kWrite:
out << "write";
return true;
case ast::Access::kReadWrite:
out << "read_write";
return true;
default:
break;
}
diagnostics_.add_error(diag::System::Writer, "unknown access");
return false;
}
bool GeneratorImpl::EmitType(std::ostream& out, const ast::Type* ty) {
return Switch(
ty,
[&](const ast::Array* ary) {
for (auto* attr : ary->attributes) {
if (auto* stride = attr->As<ast::StrideAttribute>()) {
out << "@stride(" << stride->stride << ") ";
}
}
out << "array<";
if (!EmitType(out, ary->type)) {
return false;
}
if (!ary->IsRuntimeArray()) {
out << ", ";
if (!EmitExpression(out, ary->count)) {
return false;
}
}
out << ">";
return true;
},
[&](const ast::Bool*) {
out << "bool";
return true;
},
[&](const ast::F32*) {
out << "f32";
return true;
},
[&](const ast::F16*) {
out << "f16";
return true;
},
[&](const ast::I32*) {
out << "i32";
return true;
},
[&](const ast::Matrix* mat) {
out << "mat" << mat->columns << "x" << mat->rows;
if (auto* el_ty = mat->type) {
out << "<";
if (!EmitType(out, el_ty)) {
return false;
}
out << ">";
}
return true;
},
[&](const ast::Pointer* ptr) {
out << "ptr<" << ptr->storage_class << ", ";
if (!EmitType(out, ptr->type)) {
return false;
}
if (ptr->access != ast::Access::kUndefined) {
out << ", ";
if (!EmitAccess(out, ptr->access)) {
return false;
}
}
out << ">";
return true;
},
[&](const ast::Atomic* atomic) {
out << "atomic<";
if (!EmitType(out, atomic->type)) {
return false;
}
out << ">";
return true;
},
[&](const ast::Sampler* sampler) {
out << "sampler";
if (sampler->IsComparison()) {
out << "_comparison";
}
return true;
},
[&](const ast::ExternalTexture*) {
out << "texture_external";
return true;
},
[&](const ast::Texture* texture) {
out << "texture_";
bool ok = Switch(
texture,
[&](const ast::DepthTexture*) { //
out << "depth_";
return true;
},
[&](const ast::DepthMultisampledTexture*) { //
out << "depth_multisampled_";
return true;
},
[&](const ast::SampledTexture*) { //
/* nothing to emit */
return true;
},
[&](const ast::MultisampledTexture*) { //
out << "multisampled_";
return true;
},
[&](const ast::StorageTexture*) { //
out << "storage_";
return true;
},
[&](Default) { //
diagnostics_.add_error(diag::System::Writer, "unknown texture type");
return false;
});
if (!ok) {
return false;
}
switch (texture->dim) {
case ast::TextureDimension::k1d:
out << "1d";
break;
case ast::TextureDimension::k2d:
out << "2d";
break;
case ast::TextureDimension::k2dArray:
out << "2d_array";
break;
case ast::TextureDimension::k3d:
out << "3d";
break;
case ast::TextureDimension::kCube:
out << "cube";
break;
case ast::TextureDimension::kCubeArray:
out << "cube_array";
break;
default:
diagnostics_.add_error(diag::System::Writer, "unknown texture dimension");
return false;
}
return Switch(
texture,
[&](const ast::SampledTexture* sampled) { //
out << "<";
if (!EmitType(out, sampled->type)) {
return false;
}
out << ">";
return true;
},
[&](const ast::MultisampledTexture* ms) { //
out << "<";
if (!EmitType(out, ms->type)) {
return false;
}
out << ">";
return true;
},
[&](const ast::StorageTexture* storage) { //
out << "<";
if (!EmitImageFormat(out, storage->format)) {
return false;
}
out << ", ";
if (!EmitAccess(out, storage->access)) {
return false;
}
out << ">";
return true;
},
[&](Default) { //
return true;
});
},
[&](const ast::U32*) {
out << "u32";
return true;
},
[&](const ast::Vector* vec) {
out << "vec" << vec->width;
if (auto* el_ty = vec->type) {
out << "<";
if (!EmitType(out, el_ty)) {
return false;
}
out << ">";
}
return true;
},
[&](const ast::Void*) {
out << "void";
return true;
},
[&](const ast::TypeName* tn) {
out << program_->Symbols().NameFor(tn->name);
return true;
},
[&](Default) {
diagnostics_.add_error(diag::System::Writer,
"unknown type in EmitType: " + std::string(ty->TypeInfo().name));
return false;
});
}
bool GeneratorImpl::EmitStructType(const ast::Struct* str) {
if (str->attributes.size()) {
if (!EmitAttributes(line(), str->attributes)) {
return false;
}
}
line() << "struct " << program_->Symbols().NameFor(str->name) << " {";
auto add_padding = [&](uint32_t size) {
line() << "@size(" << size << ")";
// Note: u32 is the smallest primitive we currently support. When WGSL
// supports smaller types, this will need to be updated.
line() << UniqueIdentifier("padding") << " : u32,";
};
increment_indent();
uint32_t offset = 0;
for (auto* mem : str->members) {
// TODO(crbug.com/tint/798) move the @offset attribute handling to the
// transform::Wgsl sanitizer.
if (auto* mem_sem = program_->Sem().Get(mem)) {
offset = utils::RoundUp(mem_sem->Align(), offset);
if (uint32_t padding = mem_sem->Offset() - offset) {
add_padding(padding);
offset += padding;
}
offset += mem_sem->Size();
}
// Offset attributes no longer exist in the WGSL spec, but are emitted
// by the SPIR-V reader and are consumed by the Resolver(). These should not
// be emitted, but instead struct padding fields should be emitted.
ast::AttributeList attributes_sanitized;
attributes_sanitized.reserve(mem->attributes.size());
for (auto* attr : mem->attributes) {
if (!attr->Is<ast::StructMemberOffsetAttribute>()) {
attributes_sanitized.emplace_back(attr);
}
}
if (!attributes_sanitized.empty()) {
if (!EmitAttributes(line(), attributes_sanitized)) {
return false;
}
}
auto out = line();
out << program_->Symbols().NameFor(mem->symbol) << " : ";
if (!EmitType(out, mem->type)) {
return false;
}
out << ",";
}
decrement_indent();
line() << "}";
return true;
}
bool GeneratorImpl::EmitVariable(std::ostream& out, const ast::Variable* v) {
if (!v->attributes.empty()) {
if (!EmitAttributes(out, v->attributes)) {
return false;
}
out << " ";
}
bool ok = Switch(
v, //
[&](const ast::Var* var) {
out << "var";
auto sc = var->declared_storage_class;
auto ac = var->declared_access;
if (sc != ast::StorageClass::kNone || ac != ast::Access::kUndefined) {
out << "<" << sc;
if (ac != ast::Access::kUndefined) {
out << ", ";
if (!EmitAccess(out, ac)) {
return false;
}
}
out << ">";
}
return true;
},
[&](const ast::Let*) {
out << "let";
return true;
},
[&](const ast::Override*) {
out << "override";
return true;
},
[&](const ast::Const*) {
out << "const";
return true;
},
[&](Default) {
TINT_ICE(Writer, diagnostics_) << "unhandled variable type " << v->TypeInfo().name;
return false;
});
if (!ok) {
return false;
}
out << " " << program_->Symbols().NameFor(v->symbol);
if (auto* ty = v->type) {
out << " : ";
if (!EmitType(out, ty)) {
return false;
}
}
if (v->constructor != nullptr) {
out << " = ";
if (!EmitExpression(out, v->constructor)) {
return false;
}
}
out << ";";
return true;
}
bool GeneratorImpl::EmitAttributes(std::ostream& out, const ast::AttributeList& attrs) {
bool first = true;
for (auto* attr : attrs) {
if (!first) {
out << " ";
}
first = false;
out << "@";
bool ok = Switch(
attr,
[&](const ast::WorkgroupAttribute* workgroup) {
auto values = workgroup->Values();
out << "workgroup_size(";
for (size_t i = 0; i < 3; i++) {
if (values[i]) {
if (i > 0) {
out << ", ";
}
if (!EmitExpression(out, values[i])) {
return false;
}
}
}
out << ")";
return true;
},
[&](const ast::StageAttribute* stage) {
out << stage->stage;
return true;
},
[&](const ast::BindingAttribute* binding) {
out << "binding(" << binding->value << ")";
return true;
},
[&](const ast::GroupAttribute* group) {
out << "group(" << group->value << ")";
return true;
},
[&](const ast::LocationAttribute* location) {
out << "location(" << location->value << ")";
return true;
},
[&](const ast::BuiltinAttribute* builtin) {
out << "builtin(" << builtin->builtin << ")";
return true;
},
[&](const ast::InterpolateAttribute* interpolate) {
out << "interpolate(" << interpolate->type;
if (interpolate->sampling != ast::InterpolationSampling::kNone) {
out << ", " << interpolate->sampling;
}
out << ")";
return true;
},
[&](const ast::InvariantAttribute*) {
out << "invariant";
return true;
},
[&](const ast::IdAttribute* override_deco) {
out << "id(" << override_deco->value << ")";
return true;
},
[&](const ast::StructMemberSizeAttribute* size) {
out << "size(" << size->size << ")";
return true;
},
[&](const ast::StructMemberAlignAttribute* align) {
out << "align(" << align->align << ")";
return true;
},
[&](const ast::StrideAttribute* stride) {
out << "stride(" << stride->stride << ")";
return true;
},
[&](const ast::InternalAttribute* internal) {
out << "internal(" << internal->InternalName() << ")";
return true;
},
[&](Default) {
TINT_ICE(Writer, diagnostics_)
<< "Unsupported attribute '" << attr->TypeInfo().name << "'";
return false;
});
if (!ok) {
return false;
}
}
return true;
}
bool GeneratorImpl::EmitBinary(std::ostream& out, const ast::BinaryExpression* expr) {
out << "(";
if (!EmitExpression(out, expr->lhs)) {
return false;
}
out << " ";
if (!EmitBinaryOp(out, expr->op)) {
return false;
}
out << " ";
if (!EmitExpression(out, expr->rhs)) {
return false;
}
out << ")";
return true;
}
bool GeneratorImpl::EmitBinaryOp(std::ostream& out, const ast::BinaryOp op) {
switch (op) {
case ast::BinaryOp::kAnd:
out << "&";
break;
case ast::BinaryOp::kOr:
out << "|";
break;
case ast::BinaryOp::kXor:
out << "^";
break;
case ast::BinaryOp::kLogicalAnd:
out << "&&";
break;
case ast::BinaryOp::kLogicalOr:
out << "||";
break;
case ast::BinaryOp::kEqual:
out << "==";
break;
case ast::BinaryOp::kNotEqual:
out << "!=";
break;
case ast::BinaryOp::kLessThan:
out << "<";
break;
case ast::BinaryOp::kGreaterThan:
out << ">";
break;
case ast::BinaryOp::kLessThanEqual:
out << "<=";
break;
case ast::BinaryOp::kGreaterThanEqual:
out << ">=";
break;
case ast::BinaryOp::kShiftLeft:
out << "<<";
break;
case ast::BinaryOp::kShiftRight:
out << ">>";
break;
case ast::BinaryOp::kAdd:
out << "+";
break;
case ast::BinaryOp::kSubtract:
out << "-";
break;
case ast::BinaryOp::kMultiply:
out << "*";
break;
case ast::BinaryOp::kDivide:
out << "/";
break;
case ast::BinaryOp::kModulo:
out << "%";
break;
case ast::BinaryOp::kNone:
diagnostics_.add_error(diag::System::Writer, "missing binary operation type");
return false;
}
return true;
}
bool GeneratorImpl::EmitUnaryOp(std::ostream& out, const ast::UnaryOpExpression* expr) {
switch (expr->op) {
case ast::UnaryOp::kAddressOf:
out << "&";
break;
case ast::UnaryOp::kComplement:
out << "~";
break;
case ast::UnaryOp::kIndirection:
out << "*";
break;
case ast::UnaryOp::kNot:
out << "!";
break;
case ast::UnaryOp::kNegation:
out << "-";
break;
}
out << "(";
if (!EmitExpression(out, expr->expr)) {
return false;
}
out << ")";
return true;
}
bool GeneratorImpl::EmitBlock(const ast::BlockStatement* stmt) {
line() << "{";
if (!EmitStatementsWithIndent(stmt->statements)) {
return false;
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitStatement(const ast::Statement* stmt) {
return Switch(
stmt, //
[&](const ast::AssignmentStatement* a) { return EmitAssign(a); },
[&](const ast::BlockStatement* b) { return EmitBlock(b); },
[&](const ast::BreakStatement* b) { return EmitBreak(b); },
[&](const ast::CallStatement* c) {
auto out = line();
if (!EmitCall(out, c->expr)) {
return false;
}
out << ";";
return true;
},
[&](const ast::CompoundAssignmentStatement* c) { return EmitCompoundAssign(c); },
[&](const ast::ContinueStatement* c) { return EmitContinue(c); },
[&](const ast::DiscardStatement* d) { return EmitDiscard(d); },
[&](const ast::FallthroughStatement* f) { return EmitFallthrough(f); },
[&](const ast::IfStatement* i) { return EmitIf(i); },
[&](const ast::IncrementDecrementStatement* l) { return EmitIncrementDecrement(l); },
[&](const ast::LoopStatement* l) { return EmitLoop(l); },
[&](const ast::ForLoopStatement* l) { return EmitForLoop(l); },
[&](const ast::WhileStatement* l) { return EmitWhile(l); },
[&](const ast::ReturnStatement* r) { return EmitReturn(r); },
[&](const ast::SwitchStatement* s) { return EmitSwitch(s); },
[&](const ast::VariableDeclStatement* v) { return EmitVariable(line(), v->variable); },
[&](Default) {
diagnostics_.add_error(diag::System::Writer,
"unknown statement type: " + std::string(stmt->TypeInfo().name));
return false;
});
}
bool GeneratorImpl::EmitStatements(const ast::StatementList& stmts) {
for (auto* s : stmts) {
if (!EmitStatement(s)) {
return false;
}
}
return true;
}
bool GeneratorImpl::EmitStatementsWithIndent(const ast::StatementList& stmts) {
ScopedIndent si(this);
return EmitStatements(stmts);
}
bool GeneratorImpl::EmitAssign(const ast::AssignmentStatement* stmt) {
auto out = line();
if (!EmitExpression(out, stmt->lhs)) {
return false;
}
out << " = ";
if (!EmitExpression(out, stmt->rhs)) {
return false;
}
out << ";";
return true;
}
bool GeneratorImpl::EmitBreak(const ast::BreakStatement*) {
line() << "break;";
return true;
}
bool GeneratorImpl::EmitCase(const ast::CaseStatement* stmt) {
if (stmt->IsDefault()) {
line() << "default: {";
} else {
auto out = line();
out << "case ";
bool first = true;
for (auto* selector : stmt->selectors) {
if (!first) {
out << ", ";
}
first = false;
if (!EmitLiteral(out, selector)) {
return false;
}
}
out << ": {";
}
if (!EmitStatementsWithIndent(stmt->body->statements)) {
return false;
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitCompoundAssign(const ast::CompoundAssignmentStatement* stmt) {
auto out = line();
if (!EmitExpression(out, stmt->lhs)) {
return false;
}
out << " ";
if (!EmitBinaryOp(out, stmt->op)) {
return false;
}
out << "= ";
if (!EmitExpression(out, stmt->rhs)) {
return false;
}
out << ";";
return true;
}
bool GeneratorImpl::EmitContinue(const ast::ContinueStatement*) {
line() << "continue;";
return true;
}
bool GeneratorImpl::EmitFallthrough(const ast::FallthroughStatement*) {
line() << "fallthrough;";
return true;
}
bool GeneratorImpl::EmitIf(const ast::IfStatement* stmt) {
{
auto out = line();
out << "if (";
if (!EmitExpression(out, stmt->condition)) {
return false;
}
out << ") {";
}
if (!EmitStatementsWithIndent(stmt->body->statements)) {
return false;
}
const ast::Statement* e = stmt->else_statement;
while (e) {
if (auto* elseif = e->As<ast::IfStatement>()) {
{
auto out = line();
out << "} else if (";
if (!EmitExpression(out, elseif->condition)) {
return false;
}
out << ") {";
}
if (!EmitStatementsWithIndent(elseif->body->statements)) {
return false;
}
e = elseif->else_statement;
} else {
line() << "} else {";
if (!EmitStatementsWithIndent(e->As<ast::BlockStatement>()->statements)) {
return false;
}
break;
}
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitIncrementDecrement(const ast::IncrementDecrementStatement* stmt) {
auto out = line();
if (!EmitExpression(out, stmt->lhs)) {
return false;
}
out << (stmt->increment ? "++" : "--") << ";";
return true;
}
bool GeneratorImpl::EmitDiscard(const ast::DiscardStatement*) {
line() << "discard;";
return true;
}
bool GeneratorImpl::EmitLoop(const ast::LoopStatement* stmt) {
line() << "loop {";
increment_indent();
if (!EmitStatements(stmt->body->statements)) {
return false;
}
if (stmt->continuing && !stmt->continuing->Empty()) {
line();
line() << "continuing {";
if (!EmitStatementsWithIndent(stmt->continuing->statements)) {
return false;
}
line() << "}";
}
decrement_indent();
line() << "}";
return true;
}
bool GeneratorImpl::EmitForLoop(const ast::ForLoopStatement* stmt) {
TextBuffer init_buf;
if (auto* init = stmt->initializer) {
TINT_SCOPED_ASSIGNMENT(current_buffer_, &init_buf);
if (!EmitStatement(init)) {
return false;
}
}
TextBuffer cont_buf;
if (auto* cont = stmt->continuing) {
TINT_SCOPED_ASSIGNMENT(current_buffer_, &cont_buf);
if (!EmitStatement(cont)) {
return false;
}
}
{
auto out = line();
out << "for";
{
ScopedParen sp(out);
switch (init_buf.lines.size()) {
case 0: // No initializer
break;
case 1: // Single line initializer statement
out << TrimSuffix(init_buf.lines[0].content, ";");
break;
default: // Block initializer statement
for (size_t i = 1; i < init_buf.lines.size(); i++) {
// Indent all by the first line
init_buf.lines[i].indent += current_buffer_->current_indent;
}
out << TrimSuffix(init_buf.String(), "\n");
break;
}
out << "; ";
if (auto* cond = stmt->condition) {
if (!EmitExpression(out, cond)) {
return false;
}
}
out << "; ";
switch (cont_buf.lines.size()) {
case 0: // No continuing
break;
case 1: // Single line continuing statement
out << TrimSuffix(cont_buf.lines[0].content, ";");
break;
default: // Block continuing statement
for (size_t i = 1; i < cont_buf.lines.size(); i++) {
// Indent all by the first line
cont_buf.lines[i].indent += current_buffer_->current_indent;
}
out << TrimSuffix(cont_buf.String(), "\n");
break;
}
}
out << " {";
}
if (!EmitStatementsWithIndent(stmt->body->statements)) {
return false;
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitWhile(const ast::WhileStatement* stmt) {
{
auto out = line();
out << "while";
{
ScopedParen sp(out);
auto* cond = stmt->condition;
if (!EmitExpression(out, cond)) {
return false;
}
}
out << " {";
}
if (!EmitStatementsWithIndent(stmt->body->statements)) {
return false;
}
line() << "}";
return true;
}
bool GeneratorImpl::EmitReturn(const ast::ReturnStatement* stmt) {
auto out = line();
out << "return";
if (stmt->value) {
out << " ";
if (!EmitExpression(out, stmt->value)) {
return false;
}
}
out << ";";
return true;
}
bool GeneratorImpl::EmitSwitch(const ast::SwitchStatement* stmt) {
{
auto out = line();
out << "switch(";
if (!EmitExpression(out, stmt->condition)) {
return false;
}
out << ") {";
}
{
ScopedIndent si(this);
for (auto* s : stmt->body) {
if (!EmitCase(s)) {
return false;
}
}
}
line() << "}";
return true;
}
} // namespace tint::writer::wgsl