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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Author: kenton@google.com (Kenton Varda)
// Based on original Protocol Buffers design by
// Sanjay Ghemawat, Jeff Dean, and others.
#include <compiler/cpp/cpp_enum.h>
#include <cstdint>
#include <limits>
#include <map>
#include <compiler/cpp/cpp_helpers.h>
#include <compiler/cpp/cpp_names.h>
#include <io/printer.h>
#include <stubs/strutil.h>
namespace google {
namespace protobuf {
namespace compiler {
namespace cpp {
namespace {
// The GOOGLE_ARRAYSIZE constant is the max enum value plus 1. If the max enum value
// is kint32max, GOOGLE_ARRAYSIZE will overflow. In such cases we should omit the
// generation of the GOOGLE_ARRAYSIZE constant.
bool ShouldGenerateArraySize(const EnumDescriptor* descriptor) {
int32_t max_value = descriptor->value(0)->number();
for (int i = 0; i < descriptor->value_count(); i++) {
if (descriptor->value(i)->number() > max_value) {
max_value = descriptor->value(i)->number();
}
}
return max_value != std::numeric_limits<int32_t>::max();
}
// Returns the number of unique numeric enum values. This is less than
// descriptor->value_count() when there are aliased values.
int CountUniqueValues(const EnumDescriptor* descriptor) {
std::set<int> values;
for (int i = 0; i < descriptor->value_count(); ++i) {
values.insert(descriptor->value(i)->number());
}
return values.size();
}
} // namespace
EnumGenerator::EnumGenerator(const EnumDescriptor* descriptor,
const std::map<std::string, std::string>& vars,
const Options& options)
: descriptor_(descriptor),
classname_(ClassName(descriptor, false)),
options_(options),
generate_array_size_(ShouldGenerateArraySize(descriptor)),
variables_(vars) {
variables_["classname"] = classname_;
variables_["classtype"] = QualifiedClassName(descriptor_, options);
variables_["short_name"] = descriptor_->name();
variables_["nested_name"] = descriptor_->name();
variables_["resolved_name"] = ResolveKeyword(descriptor_->name());
variables_["prefix"] =
(descriptor_->containing_type() == NULL) ? "" : classname_ + "_";
}
EnumGenerator::~EnumGenerator() {}
void EnumGenerator::GenerateDefinition(io::Printer* printer) {
Formatter format(printer, variables_);
format("enum ${1$$classname$$}$ : int {\n", descriptor_);
format.Indent();
const EnumValueDescriptor* min_value = descriptor_->value(0);
const EnumValueDescriptor* max_value = descriptor_->value(0);
for (int i = 0; i < descriptor_->value_count(); i++) {
auto format_value = format;
format_value.Set("name", EnumValueName(descriptor_->value(i)));
// In C++, an value of -2147483648 gets interpreted as the negative of
// 2147483648, and since 2147483648 can't fit in an integer, this produces a
// compiler warning. This works around that issue.
format_value.Set("number", Int32ToString(descriptor_->value(i)->number()));
format_value.Set("deprecation",
DeprecatedAttribute(options_, descriptor_->value(i)));
if (i > 0) format_value(",\n");
format_value("${1$$prefix$$name$$}$ $deprecation$= $number$",
descriptor_->value(i));
if (descriptor_->value(i)->number() < min_value->number()) {
min_value = descriptor_->value(i);
}
if (descriptor_->value(i)->number() > max_value->number()) {
max_value = descriptor_->value(i);
}
}
if (descriptor_->file()->syntax() == FileDescriptor::SYNTAX_PROTO3) {
// For new enum semantics: generate min and max sentinel values equal to
// INT32_MIN and INT32_MAX
if (descriptor_->value_count() > 0) format(",\n");
format(
"$classname$_$prefix$INT_MIN_SENTINEL_DO_NOT_USE_ = "
"std::numeric_limits<$int32$>::min(),\n"
"$classname$_$prefix$INT_MAX_SENTINEL_DO_NOT_USE_ = "
"std::numeric_limits<$int32$>::max()");
}
format.Outdent();
format("\n};\n");
format(
"$dllexport_decl $bool $classname$_IsValid(int value);\n"
"constexpr $classname$ ${1$$prefix$$short_name$_MIN$}$ = "
"$prefix$$2$;\n"
"constexpr $classname$ ${1$$prefix$$short_name$_MAX$}$ = "
"$prefix$$3$;\n",
descriptor_, EnumValueName(min_value), EnumValueName(max_value));
if (generate_array_size_) {
format(
"constexpr int ${1$$prefix$$short_name$_ARRAYSIZE$}$ = "
"$prefix$$short_name$_MAX + 1;\n\n",
descriptor_);
}
if (HasDescriptorMethods(descriptor_->file(), options_)) {
format(
"$dllexport_decl $const ::$proto_ns$::EnumDescriptor* "
"$classname$_descriptor();\n");
}
// The _Name and _Parse functions. The lite implementation is table-based, so
// we make sure to keep the tables hidden in the .cc file.
if (!HasDescriptorMethods(descriptor_->file(), options_)) {
format("const std::string& $classname$_Name($classname$ value);\n");
}
// The _Name() function accepts the enum type itself but also any integral
// type.
format(
"template<typename T>\n"
"inline const std::string& $classname$_Name(T enum_t_value) {\n"
" static_assert(::std::is_same<T, $classname$>::value ||\n"
" ::std::is_integral<T>::value,\n"
" \"Incorrect type passed to function $classname$_Name.\");\n");
if (HasDescriptorMethods(descriptor_->file(), options_)) {
format(
" return ::$proto_ns$::internal::NameOfEnum(\n"
" $classname$_descriptor(), enum_t_value);\n");
} else {
format(
" return $classname$_Name(static_cast<$classname$>(enum_t_value));\n");
}
format("}\n");
if (HasDescriptorMethods(descriptor_->file(), options_)) {
format(
"inline bool $classname$_Parse(\n"
" ::PROTOBUF_NAMESPACE_ID::ConstStringParam name, $classname$* "
"value) "
"{\n"
" return ::$proto_ns$::internal::ParseNamedEnum<$classname$>(\n"
" $classname$_descriptor(), name, value);\n"
"}\n");
} else {
format(
"bool $classname$_Parse(\n"
" ::PROTOBUF_NAMESPACE_ID::ConstStringParam name, $classname$* "
"value);\n");
}
}
void EnumGenerator::GenerateGetEnumDescriptorSpecializations(
io::Printer* printer) {
Formatter format(printer, variables_);
format(
"template <> struct is_proto_enum< $classtype$> : ::std::true_type "
"{};\n");
if (HasDescriptorMethods(descriptor_->file(), options_)) {
format(
"template <>\n"
"inline const EnumDescriptor* GetEnumDescriptor< $classtype$>() {\n"
" return $classtype$_descriptor();\n"
"}\n");
}
}
void EnumGenerator::GenerateSymbolImports(io::Printer* printer) const {
Formatter format(printer, variables_);
format("typedef $classname$ $resolved_name$;\n");
for (int j = 0; j < descriptor_->value_count(); j++) {
std::string deprecated_attr =
DeprecatedAttribute(options_, descriptor_->value(j));
format(
"$1$static constexpr $resolved_name$ ${2$$3$$}$ =\n"
" $classname$_$3$;\n",
deprecated_attr, descriptor_->value(j),
EnumValueName(descriptor_->value(j)));
}
format(
"static inline bool $nested_name$_IsValid(int value) {\n"
" return $classname$_IsValid(value);\n"
"}\n"
"static constexpr $resolved_name$ ${1$$nested_name$_MIN$}$ =\n"
" $classname$_$nested_name$_MIN;\n"
"static constexpr $resolved_name$ ${1$$nested_name$_MAX$}$ =\n"
" $classname$_$nested_name$_MAX;\n",
descriptor_);
if (generate_array_size_) {
format(
"static constexpr int ${1$$nested_name$_ARRAYSIZE$}$ =\n"
" $classname$_$nested_name$_ARRAYSIZE;\n",
descriptor_);
}
if (HasDescriptorMethods(descriptor_->file(), options_)) {
format(
"static inline const ::$proto_ns$::EnumDescriptor*\n"
"$nested_name$_descriptor() {\n"
" return $classname$_descriptor();\n"
"}\n");
}
format(
"template<typename T>\n"
"static inline const std::string& $nested_name$_Name(T enum_t_value) {\n"
" static_assert(::std::is_same<T, $resolved_name$>::value ||\n"
" ::std::is_integral<T>::value,\n"
" \"Incorrect type passed to function $nested_name$_Name.\");\n"
" return $classname$_Name(enum_t_value);\n"
"}\n");
format(
"static inline bool "
"$nested_name$_Parse(::PROTOBUF_NAMESPACE_ID::ConstStringParam name,\n"
" $resolved_name$* value) {\n"
" return $classname$_Parse(name, value);\n"
"}\n");
}
void EnumGenerator::GenerateMethods(int idx, io::Printer* printer) {
Formatter format(printer, variables_);
if (HasDescriptorMethods(descriptor_->file(), options_)) {
format(
"const ::$proto_ns$::EnumDescriptor* $classname$_descriptor() {\n"
" ::$proto_ns$::internal::AssignDescriptors(&$desc_table$);\n"
" return $file_level_enum_descriptors$[$1$];\n"
"}\n",
idx);
}
format(
"bool $classname$_IsValid(int value) {\n"
" switch (value) {\n");
// Multiple values may have the same number. Make sure we only cover
// each number once by first constructing a set containing all valid
// numbers, then printing a case statement for each element.
std::set<int> numbers;
for (int j = 0; j < descriptor_->value_count(); j++) {
const EnumValueDescriptor* value = descriptor_->value(j);
numbers.insert(value->number());
}
for (std::set<int>::iterator iter = numbers.begin(); iter != numbers.end();
++iter) {
format(" case $1$:\n", Int32ToString(*iter));
}
format(
" return true;\n"
" default:\n"
" return false;\n"
" }\n"
"}\n"
"\n");
if (!HasDescriptorMethods(descriptor_->file(), options_)) {
// In lite mode (where descriptors are unavailable), we generate separate
// tables for mapping between enum names and numbers. The _entries table
// contains the bulk of the data and is sorted by name, while
// _entries_by_number is sorted by number and just contains pointers into
// _entries. The two tables allow mapping from name to number and number to
// name, both in time logarithmic in the number of enum entries. This could
// probably be made faster, but for now the tables are intended to be simple
// and compact.
//
// Enums with allow_alias = true support multiple entries with the same
// numerical value. In cases where there are multiple names for the same
// number, we treat the first name appearing in the .proto file as the
// canonical one.
std::map<std::string, int> name_to_number;
std::map<int, std::string> number_to_canonical_name;
for (int i = 0; i < descriptor_->value_count(); i++) {
const EnumValueDescriptor* value = descriptor_->value(i);
name_to_number.emplace(value->name(), value->number());
// The same number may appear with multiple names, so we use emplace() to
// let the first name win.
number_to_canonical_name.emplace(value->number(), value->name());
}
format(
"static ::$proto_ns$::internal::ExplicitlyConstructed<std::string> "
"$classname$_strings[$1$] = {};\n\n",
CountUniqueValues(descriptor_));
// We concatenate all the names for a given enum into one big string
// literal. If instead we store an array of string literals, the linker
// seems to put all enum strings for a given .proto file in the same
// section, which hinders its ability to strip out unused strings.
format("static const char $classname$_names[] =");
for (const auto& p : name_to_number) {
format("\n \"$1$\"", p.first);
}
format(";\n\n");
format(
"static const ::$proto_ns$::internal::EnumEntry $classname$_entries[] "
"= {\n");
int i = 0;
std::map<int, int> number_to_index;
int data_index = 0;
for (const auto& p : name_to_number) {
format(" { {$classname$_names + $1$, $2$}, $3$ },\n", data_index,
p.first.size(), p.second);
if (number_to_canonical_name[p.second] == p.first) {
number_to_index.emplace(p.second, i);
}
++i;
data_index += p.first.size();
}
format(
"};\n"
"\n"
"static const int $classname$_entries_by_number[] = {\n");
for (const auto& p : number_to_index) {
format(" $1$, // $2$ -> $3$\n", p.second, p.first,
number_to_canonical_name[p.first]);
}
format(
"};\n"
"\n");
format(
"const std::string& $classname$_Name(\n"
" $classname$ value) {\n"
" static const bool dummy =\n"
" ::$proto_ns$::internal::InitializeEnumStrings(\n"
" $classname$_entries,\n"
" $classname$_entries_by_number,\n"
" $1$, $classname$_strings);\n"
" (void) dummy;\n"
" int idx = ::$proto_ns$::internal::LookUpEnumName(\n"
" $classname$_entries,\n"
" $classname$_entries_by_number,\n"
" $1$, value);\n"
" return idx == -1 ? ::$proto_ns$::internal::GetEmptyString() :\n"
" $classname$_strings[idx].get();\n"
"}\n",
CountUniqueValues(descriptor_));
format(
"bool $classname$_Parse(\n"
" ::PROTOBUF_NAMESPACE_ID::ConstStringParam name, $classname$* "
"value) "
"{\n"
" int int_value;\n"
" bool success = ::$proto_ns$::internal::LookUpEnumValue(\n"
" $classname$_entries, $1$, name, &int_value);\n"
" if (success) {\n"
" *value = static_cast<$classname$>(int_value);\n"
" }\n"
" return success;\n"
"}\n",
descriptor_->value_count());
}
if (descriptor_->containing_type() != NULL) {
std::string parent = ClassName(descriptor_->containing_type(), false);
// Before C++17, we must define the static constants which were
// declared in the header, to give the linker a place to put them.
// But MSVC++ pre-2015 and post-2017 (version 15.5+) insists that we not.
format(
"#if (__cplusplus < 201703) && "
"(!defined(_MSC_VER) || (_MSC_VER >= 1900 && _MSC_VER < 1912))\n");
for (int i = 0; i < descriptor_->value_count(); i++) {
format("constexpr $classname$ $1$::$2$;\n", parent,
EnumValueName(descriptor_->value(i)));
}
format(
"constexpr $classname$ $1$::$nested_name$_MIN;\n"
"constexpr $classname$ $1$::$nested_name$_MAX;\n",
parent);
if (generate_array_size_) {
format("constexpr int $1$::$nested_name$_ARRAYSIZE;\n", parent);
}
format(
"#endif // (__cplusplus < 201703) && "
"(!defined(_MSC_VER) || (_MSC_VER >= 1900 && _MSC_VER < 1912))\n");
}
}
} // namespace cpp
} // namespace compiler
} // namespace protobuf
} // namespace google
|