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// Protocol Buffers - Google's data interchange format
// Copyright 2023 Google LLC. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
#include "upb_generator/protoc-gen-upb_minitable.h"
#include <string.h>
#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <map>
#include <string>
#include <utility>
#include <vector>
#include "absl/container/flat_hash_set.h"
#include "absl/log/absl_check.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"
#include "absl/strings/substitute.h"
#include "google/protobuf/compiler/code_generator.h"
#include "upb/base/descriptor_constants.h"
#include "upb/mini_table/enum.h"
#include "upb/mini_table/field.h"
#include "upb/mini_table/internal/field.h"
#include "upb/mini_table/message.h"
#include "upb/reflection/def.hpp"
#include "upb/wire/types.h"
#include "upb_generator/common.h"
#include "upb_generator/file_layout.h"
// Must be last.
#include "upb/port/def.inc"
#include "upb_generator/plugin.h"
namespace upb {
namespace generator {
namespace {
// Returns fields in order of "hotness", eg. how frequently they appear in
// serialized payloads. Ideally this will use a profile. When we don't have
// that, we assume that fields with smaller numbers are used more frequently.
inline std::vector<upb::FieldDefPtr> FieldHotnessOrder(
upb::MessageDefPtr message) {
std::vector<upb::FieldDefPtr> fields;
size_t field_count = message.field_count();
fields.reserve(field_count);
for (size_t i = 0; i < field_count; i++) {
fields.push_back(message.field(i));
}
std::sort(fields.begin(), fields.end(),
[](upb::FieldDefPtr a, upb::FieldDefPtr b) {
return std::make_pair(!a.is_required(), a.number()) <
std::make_pair(!b.is_required(), b.number());
});
return fields;
}
std::string ExtensionIdentBase(upb::FieldDefPtr ext) {
UPB_ASSERT(ext.is_extension());
std::string ext_scope;
if (ext.extension_scope()) {
return MessageName(ext.extension_scope());
} else {
return ToCIdent(ext.file().package());
}
}
std::string ExtensionLayout(upb::FieldDefPtr ext) {
return absl::StrCat(ExtensionIdentBase(ext), "_", ext.name(), "_ext");
}
std::string MessagePtrName(upb::MessageDefPtr message) {
return MessageInitName(message) + "_ptr";
}
const char* kEnumsInit = "enums_layout";
const char* kExtensionsInit = "extensions_layout";
const char* kMessagesInit = "messages_layout";
typedef std::pair<std::string, uint64_t> TableEntry;
uint32_t GetWireTypeForField(upb::FieldDefPtr field) {
if (field.packed()) return kUpb_WireType_Delimited;
switch (field.type()) {
case kUpb_FieldType_Double:
case kUpb_FieldType_Fixed64:
case kUpb_FieldType_SFixed64:
return kUpb_WireType_64Bit;
case kUpb_FieldType_Float:
case kUpb_FieldType_Fixed32:
case kUpb_FieldType_SFixed32:
return kUpb_WireType_32Bit;
case kUpb_FieldType_Int64:
case kUpb_FieldType_UInt64:
case kUpb_FieldType_Int32:
case kUpb_FieldType_Bool:
case kUpb_FieldType_UInt32:
case kUpb_FieldType_Enum:
case kUpb_FieldType_SInt32:
case kUpb_FieldType_SInt64:
return kUpb_WireType_Varint;
case kUpb_FieldType_Group:
return kUpb_WireType_StartGroup;
case kUpb_FieldType_Message:
case kUpb_FieldType_String:
case kUpb_FieldType_Bytes:
return kUpb_WireType_Delimited;
}
UPB_UNREACHABLE();
}
uint32_t MakeTag(uint32_t field_number, uint32_t wire_type) {
return field_number << 3 | wire_type;
}
size_t WriteVarint32ToArray(uint64_t val, char* buf) {
size_t i = 0;
do {
uint8_t byte = val & 0x7fU;
val >>= 7;
if (val) byte |= 0x80U;
buf[i++] = byte;
} while (val);
return i;
}
uint64_t GetEncodedTag(upb::FieldDefPtr field) {
uint32_t wire_type = GetWireTypeForField(field);
uint32_t unencoded_tag = MakeTag(field.number(), wire_type);
char tag_bytes[10] = {0};
WriteVarint32ToArray(unencoded_tag, tag_bytes);
uint64_t encoded_tag = 0;
memcpy(&encoded_tag, tag_bytes, sizeof(encoded_tag));
// TODO: byte-swap for big endian.
return encoded_tag;
}
int GetTableSlot(upb::FieldDefPtr field) {
uint64_t tag = GetEncodedTag(field);
if (tag > 0x7fff) {
// Tag must fit within a two-byte varint.
return -1;
}
return (tag & 0xf8) >> 3;
}
bool TryFillTableEntry(const DefPoolPair& pools, upb::FieldDefPtr field,
TableEntry& ent) {
const upb_MiniTable* mt = pools.GetMiniTable64(field.containing_type());
const upb_MiniTableField* mt_f =
upb_MiniTable_FindFieldByNumber(mt, field.number());
std::string type = "";
std::string cardinality = "";
switch (upb_MiniTableField_Type(mt_f)) {
case kUpb_FieldType_Bool:
type = "b1";
break;
case kUpb_FieldType_Enum:
if (upb_MiniTableField_IsClosedEnum(mt_f)) {
// We don't have the means to test proto2 enum fields for valid values.
return false;
}
[[fallthrough]];
case kUpb_FieldType_Int32:
case kUpb_FieldType_UInt32:
type = "v4";
break;
case kUpb_FieldType_Int64:
case kUpb_FieldType_UInt64:
type = "v8";
break;
case kUpb_FieldType_Fixed32:
case kUpb_FieldType_SFixed32:
case kUpb_FieldType_Float:
type = "f4";
break;
case kUpb_FieldType_Fixed64:
case kUpb_FieldType_SFixed64:
case kUpb_FieldType_Double:
type = "f8";
break;
case kUpb_FieldType_SInt32:
type = "z4";
break;
case kUpb_FieldType_SInt64:
type = "z8";
break;
case kUpb_FieldType_String:
type = "s";
break;
case kUpb_FieldType_Bytes:
type = "b";
break;
case kUpb_FieldType_Message:
type = "m";
break;
default:
return false; // Not supported yet.
}
if (upb_MiniTableField_IsArray(mt_f)) {
cardinality = upb_MiniTableField_IsPacked(mt_f) ? "p" : "r";
} else if (upb_MiniTableField_IsScalar(mt_f)) {
cardinality = upb_MiniTableField_IsInOneof(mt_f) ? "o" : "s";
} else {
return false; // Not supported yet (ever?).
}
uint64_t expected_tag = GetEncodedTag(field);
// Data is:
//
// 48 32 16 0
// |--------|--------|--------|--------|--------|--------|--------|--------|
// | offset (16) |case offset (16) |presence| submsg | exp. tag (16) |
// |--------|--------|--------|--------|--------|--------|--------|--------|
//
// - |presence| is either hasbit index or field number for oneofs.
uint64_t data =
static_cast<uint64_t>(mt_f->UPB_PRIVATE(offset)) << 48 | expected_tag;
if (field.IsSequence()) {
// No hasbit/oneof-related fields.
}
if (field.real_containing_oneof()) {
uint64_t case_offset = ~mt_f->presence;
if (case_offset > 0xffff || field.number() > 0xff) return false;
data |= field.number() << 24;
data |= case_offset << 32;
} else {
uint64_t hasbit_index = 63; // No hasbit (set a high, unused bit).
if (mt_f->presence) {
hasbit_index = mt_f->presence;
if (hasbit_index > 31) return false;
}
data |= hasbit_index << 24;
}
if (field.ctype() == kUpb_CType_Message) {
uint64_t idx = mt_f->UPB_PRIVATE(submsg_index);
if (idx > 255) return false;
data |= idx << 16;
std::string size_ceil = "max";
size_t size = SIZE_MAX;
if (field.message_type().file() == field.file()) {
// We can only be guaranteed the size of the sub-message if it is in the
// same file as us. We could relax this to increase the speed of
// cross-file sub-message parsing if we are comfortable requiring that
// users compile all messages at the same time.
const upb_MiniTable* sub_mt = pools.GetMiniTable64(field.message_type());
size = sub_mt->UPB_PRIVATE(size) + 8;
}
std::vector<size_t> breaks = {64, 128, 192, 256};
for (auto brk : breaks) {
if (size <= brk) {
size_ceil = std::to_string(brk);
break;
}
}
ent.first = absl::Substitute("upb_p$0$1_$2bt_max$3b", cardinality, type,
expected_tag > 0xff ? "2" : "1", size_ceil);
} else {
ent.first = absl::Substitute("upb_p$0$1_$2bt", cardinality, type,
expected_tag > 0xff ? "2" : "1");
}
ent.second = data;
return true;
}
std::vector<TableEntry> FastDecodeTable(upb::MessageDefPtr message,
const DefPoolPair& pools) {
std::vector<TableEntry> table;
for (const auto field : FieldHotnessOrder(message)) {
TableEntry ent;
int slot = GetTableSlot(field);
// std::cerr << "table slot: " << field->number() << ": " << slot << "\n";
if (slot < 0) {
// Tag can't fit in the table.
continue;
}
if (!TryFillTableEntry(pools, field, ent)) {
// Unsupported field type or offset, hasbit index, etc. doesn't fit.
continue;
}
while ((size_t)slot >= table.size()) {
size_t size = std::max(static_cast<size_t>(1), table.size() * 2);
table.resize(size, TableEntry{"_upb_FastDecoder_DecodeGeneric", 0});
}
if (table[slot].first != "_upb_FastDecoder_DecodeGeneric") {
// A hotter field already filled this slot.
continue;
}
table[slot] = ent;
}
return table;
}
std::string ArchDependentSize(int64_t size32, int64_t size64) {
if (size32 == size64) return absl::StrCat(size32);
return absl::Substitute("UPB_SIZE($0, $1)", size32, size64);
}
std::string FieldInitializer(const DefPoolPair& pools, upb::FieldDefPtr field) {
return upb::generator::FieldInitializer(field, pools.GetField64(field),
pools.GetField32(field));
}
// Writes a single field into a .upb.c source file.
void WriteMessageField(upb::FieldDefPtr field,
const upb_MiniTableField* field64,
const upb_MiniTableField* field32, Output& output) {
output(" $0,\n", upb::generator::FieldInitializer(field, field64, field32));
}
std::string GetSub(upb::FieldDefPtr field, bool is_extension) {
if (auto message_def = field.message_type()) {
return absl::Substitute("{.UPB_PRIVATE(submsg) = &$0}",
is_extension ? MessageInitName(message_def)
: MessagePtrName(message_def));
}
if (auto enum_def = field.enum_subdef()) {
if (enum_def.is_closed()) {
return absl::Substitute("{.UPB_PRIVATE(subenum) = &$0}",
EnumInit(enum_def));
}
}
return std::string("{.UPB_PRIVATE(submsg) = NULL}");
}
bool IsCrossFile(upb::FieldDefPtr field) {
return field.message_type() != field.containing_type();
}
// Writes a single message into a .upb.c source file.
void WriteMessage(upb::MessageDefPtr message, const DefPoolPair& pools,
const MiniTableOptions& options, Output& output) {
std::string msg_name = ToCIdent(message.full_name());
std::string fields_array_ref = "NULL";
std::string submsgs_array_ref = "NULL";
std::string subenums_array_ref = "NULL";
const upb_MiniTable* mt_32 = pools.GetMiniTable32(message);
const upb_MiniTable* mt_64 = pools.GetMiniTable64(message);
std::map<int, std::string> subs;
absl::flat_hash_set<const upb_MiniTable*> seen;
// Construct map of sub messages by field number.
for (int i = 0; i < mt_64->UPB_PRIVATE(field_count); i++) {
const upb_MiniTableField* f = &mt_64->UPB_PRIVATE(fields)[i];
uint32_t index = f->UPB_PRIVATE(submsg_index);
if (index != kUpb_NoSub) {
const int f_number = upb_MiniTableField_Number(f);
upb::FieldDefPtr field = message.FindFieldByNumber(f_number);
auto pair = subs.emplace(index, GetSub(field, false));
ABSL_CHECK(pair.second);
if (options.one_output_per_message && field.IsSubMessage() &&
IsCrossFile(field) && !upb_MiniTableField_IsMap(f)) {
if (seen.insert(pools.GetMiniTable64(field.message_type())).second) {
output(
"__attribute__((weak)) const upb_MiniTable* $0 ="
" &UPB_PRIVATE(_kUpb_MiniTable_StaticallyTreeShaken);\n",
MessagePtrName(field.message_type()));
}
}
}
}
// Write upb_MiniTableSubInternal table for sub messages referenced from
// fields.
if (!subs.empty()) {
std::string submsgs_array_name = msg_name + "_submsgs";
submsgs_array_ref = "&" + submsgs_array_name + "[0]";
output("static const upb_MiniTableSubInternal $0[$1] = {\n",
submsgs_array_name, subs.size());
int i = 0;
for (const auto& pair : subs) {
ABSL_CHECK(pair.first == i++);
output(" $0,\n", pair.second);
}
output("};\n\n");
}
// Write upb_MiniTableField table.
if (mt_64->UPB_PRIVATE(field_count) > 0) {
std::string fields_array_name = msg_name + "__fields";
fields_array_ref = "&" + fields_array_name + "[0]";
output("static const upb_MiniTableField $0[$1] = {\n", fields_array_name,
mt_64->UPB_PRIVATE(field_count));
for (int i = 0; i < mt_64->UPB_PRIVATE(field_count); i++) {
WriteMessageField(message.FindFieldByNumber(
mt_64->UPB_PRIVATE(fields)[i].UPB_PRIVATE(number)),
&mt_64->UPB_PRIVATE(fields)[i],
&mt_32->UPB_PRIVATE(fields)[i], output);
}
output("};\n\n");
}
std::vector<TableEntry> table;
uint8_t table_mask = ~0;
table = FastDecodeTable(message, pools);
if (table.size() > 1) {
UPB_ASSERT((table.size() & (table.size() - 1)) == 0);
table_mask = (table.size() - 1) << 3;
}
std::string msgext = "kUpb_ExtMode_NonExtendable";
if (message.extension_range_count()) {
if (UPB_DESC(MessageOptions_message_set_wire_format)(message.options())) {
msgext = "kUpb_ExtMode_IsMessageSet";
} else {
msgext = "kUpb_ExtMode_Extendable";
}
}
output("const upb_MiniTable $0 = {\n", MessageInitName(message));
output(" $0,\n", submsgs_array_ref);
output(" $0,\n", fields_array_ref);
output(" $0, $1, $2, $3, UPB_FASTTABLE_MASK($4), $5,\n",
ArchDependentSize(mt_32->UPB_PRIVATE(size), mt_64->UPB_PRIVATE(size)),
mt_64->UPB_PRIVATE(field_count), msgext,
mt_64->UPB_PRIVATE(dense_below), table_mask,
mt_64->UPB_PRIVATE(required_count));
output("#ifdef UPB_TRACING_ENABLED\n");
output(" \"$0\",\n", message.full_name());
output("#endif\n");
if (!table.empty()) {
output(" UPB_FASTTABLE_INIT({\n");
for (const auto& ent : table) {
output(" {0x$1, &$0},\n", ent.first,
absl::StrCat(absl::Hex(ent.second, absl::kZeroPad16)));
}
output(" })\n");
}
output("};\n\n");
output("const upb_MiniTable* $0 = &$1;\n", MessagePtrName(message),
MessageInitName(message));
}
void WriteEnum(upb::EnumDefPtr e, Output& output) {
std::string values_init = "{\n";
const upb_MiniTableEnum* mt = e.mini_table();
uint32_t value_count =
(mt->UPB_PRIVATE(mask_limit) / 32) + mt->UPB_PRIVATE(value_count);
for (uint32_t i = 0; i < value_count; i++) {
absl::StrAppend(&values_init, " 0x",
absl::Hex(mt->UPB_PRIVATE(data)[i]), ",\n");
}
values_init += " }";
output(
R"cc(
const upb_MiniTableEnum $0 = {
$1,
$2,
$3,
};
)cc",
EnumInit(e), mt->UPB_PRIVATE(mask_limit), mt->UPB_PRIVATE(value_count),
values_init);
output("\n");
}
void WriteExtension(const DefPoolPair& pools, upb::FieldDefPtr ext,
Output& output) {
output("UPB_LINKARR_APPEND(upb_AllExts)\n");
output("const upb_MiniTableExtension $0 = {\n ", ExtensionLayout(ext));
output("$0,\n", FieldInitializer(pools, ext));
output(" &$0,\n", MessageInitName(ext.containing_type()));
output(" $0,\n", GetSub(ext, true));
output("\n};\n");
}
} // namespace
void WriteMiniTableHeader(const DefPoolPair& pools, upb::FileDefPtr file,
const MiniTableOptions& options, Output& output) {
EmitFileWarning(file.name(), output);
output(
"#ifndef $0_UPB_MINITABLE_H_\n"
"#define $0_UPB_MINITABLE_H_\n\n"
"#include \"upb/generated_code_support.h\"\n",
ToPreproc(file.name()));
for (int i = 0; i < file.public_dependency_count(); i++) {
if (i == 0) {
output("/* Public Imports. */\n");
}
output(
"#include \"$0\"\n",
MiniTableHeaderFilename(file.public_dependency(i), options.bootstrap));
if (i == file.public_dependency_count() - 1) {
output("\n");
}
}
output(
"\n"
"// Must be last.\n"
"#include \"upb/port/def.inc\"\n"
"\n"
"#ifdef __cplusplus\n"
"extern \"C\" {\n"
"#endif\n"
"\n");
const std::vector<upb::MessageDefPtr> this_file_messages =
SortedMessages(file);
const std::vector<upb::FieldDefPtr> this_file_exts = SortedExtensions(file);
for (auto message : this_file_messages) {
output("extern const upb_MiniTable $0;\n", MessageInitName(message));
output("extern const upb_MiniTable* $0;\n", MessagePtrName(message));
}
for (auto ext : this_file_exts) {
output("extern const upb_MiniTableExtension $0;\n", ExtensionLayout(ext));
}
output("\n");
std::vector<upb::EnumDefPtr> this_file_enums =
SortedEnums(file, kClosedEnums);
for (const auto enumdesc : this_file_enums) {
output("extern const upb_MiniTableEnum $0;\n", EnumInit(enumdesc));
}
output("extern const upb_MiniTableFile $0;\n\n", FileLayoutName(file));
output(
"#ifdef __cplusplus\n"
"} /* extern \"C\" */\n"
"#endif\n"
"\n"
"#include \"upb/port/undef.inc\"\n"
"\n"
"#endif /* $0_UPB_MINITABLE_H_ */\n",
ToPreproc(file.name()));
}
void WriteMiniTableSourceIncludes(upb::FileDefPtr file,
const MiniTableOptions& options,
Output& output) {
EmitFileWarning(file.name(), output);
output(
"#include <stddef.h>\n"
"#include \"upb/generated_code_support.h\"\n"
"#include \"$0\"\n",
MiniTableHeaderFilename(file, options.bootstrap));
for (int i = 0; i < file.dependency_count(); i++) {
if (options.strip_nonfunctional_codegen &&
google::protobuf::compiler::IsKnownFeatureProto(file.dependency(i).name())) {
// Strip feature imports for editions codegen tests.
continue;
}
output("#include \"$0\"\n",
MiniTableHeaderFilename(file.dependency(i), options.bootstrap));
}
output(
"\n"
"// Must be last.\n"
"#include \"upb/port/def.inc\"\n"
"\n");
output(
"extern const struct upb_MiniTable "
"UPB_PRIVATE(_kUpb_MiniTable_StaticallyTreeShaken);\n");
}
void WriteMiniTableSource(const DefPoolPair& pools, upb::FileDefPtr file,
const MiniTableOptions& options, Output& output) {
WriteMiniTableSourceIncludes(file, options, output);
std::vector<upb::MessageDefPtr> messages = SortedMessages(file);
std::vector<upb::FieldDefPtr> extensions = SortedExtensions(file);
std::vector<upb::EnumDefPtr> enums = SortedEnums(file, kClosedEnums);
if (options.one_output_per_message) {
for (auto message : messages) {
output("extern const upb_MiniTable* $0;\n", MessagePtrName(message));
}
for (const auto e : enums) {
output("extern const upb_MiniTableEnum $0;\n", EnumInit(e));
}
for (const auto ext : extensions) {
output("extern const upb_MiniTableExtension $0;\n", ExtensionLayout(ext));
}
} else {
for (auto message : messages) {
WriteMessage(message, pools, options, output);
}
for (const auto e : enums) {
WriteEnum(e, output);
}
for (const auto ext : extensions) {
WriteExtension(pools, ext, output);
}
}
// Messages.
if (!messages.empty()) {
output("static const upb_MiniTable *$0[$1] = {\n", kMessagesInit,
messages.size());
for (auto message : messages) {
output(" &$0,\n", MessageInitName(message));
}
output("};\n");
output("\n");
}
// Enums.
if (!enums.empty()) {
output("static const upb_MiniTableEnum *$0[$1] = {\n", kEnumsInit,
enums.size());
for (const auto e : enums) {
output(" &$0,\n", EnumInit(e));
}
output("};\n");
output("\n");
}
if (!extensions.empty()) {
// Extensions.
output(
"\n"
"static const upb_MiniTableExtension *$0[$1] = {\n",
kExtensionsInit, extensions.size());
for (auto ext : extensions) {
output(" &$0,\n", ExtensionLayout(ext));
}
output(
"};\n"
"\n");
}
output("const upb_MiniTableFile $0 = {\n", FileLayoutName(file));
output(" $0,\n", messages.empty() ? "NULL" : kMessagesInit);
output(" $0,\n", enums.empty() ? "NULL" : kEnumsInit);
output(" $0,\n", extensions.empty() ? "NULL" : kExtensionsInit);
output(" $0,\n", messages.size());
output(" $0,\n", enums.size());
output(" $0,\n", extensions.size());
output("};\n\n");
output("#include \"upb/port/undef.inc\"\n");
output("\n");
}
std::string MultipleSourceFilename(upb::FileDefPtr file,
absl::string_view full_name, int* i) {
*i += 1;
return absl::StrCat(StripExtension(file.name()), ".upb_weak_minitables/",
*i, ".upb.c");
}
void WriteMiniTableMultipleSources(const DefPoolPair& pools,
upb::FileDefPtr file,
const MiniTableOptions& options,
Plugin* plugin) {
std::vector<upb::MessageDefPtr> messages = SortedMessages(file);
std::vector<upb::FieldDefPtr> extensions = SortedExtensions(file);
std::vector<upb::EnumDefPtr> enums = SortedEnums(file, kClosedEnums);
int i = 0;
for (auto message : messages) {
Output output;
WriteMiniTableSourceIncludes(file, options, output);
WriteMessage(message, pools, options, output);
plugin->AddOutputFile(MultipleSourceFilename(file, message.full_name(), &i),
output.output());
}
for (const auto e : enums) {
Output output;
WriteMiniTableSourceIncludes(file, options, output);
WriteEnum(e, output);
plugin->AddOutputFile(MultipleSourceFilename(file, e.full_name(), &i),
output.output());
}
for (const auto ext : extensions) {
Output output;
WriteMiniTableSourceIncludes(file, options, output);
WriteExtension(pools, ext, output);
plugin->AddOutputFile(MultipleSourceFilename(file, ext.full_name(), &i),
output.output());
}
}
} // namespace generator
} // namespace upb