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zhangskz
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In OSS mode omit some extern template specializations. We have seen reports of
compilers falling over due to the size of translation units. PiperOrigin-RevId: 549653990
1 parent 87ffe68 commit 2ed49c9

9 files changed

Lines changed: 28 additions & 221 deletions

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‎src/google/protobuf/compiler/cpp/file.cc‎

Lines changed: 12 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -1242,11 +1242,18 @@ class FileGenerator::ForwardDeclarations {
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}
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void PrintTopLevelDecl(io::Printer* p, const Options& options) const {
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for (const auto& c : classes_) {
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p->Emit({{"class", QualifiedClassName(c.second, options)}}, R"cc(
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template <>
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$dllexport_decl $$class$* Arena::CreateMaybeMessage<$class$>(Arena*);
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)cc");
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if (ShouldGenerateExternSpecializations(options)) {
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for (const auto& c : classes_) {
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// To reduce total linker input size in large binaries we make these
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// functions extern and define then in the pb.cc file. This avoids bloat
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// in callers by having duplicate definitions of the template.
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// However, it increases the size of the pb.cc translation units so it
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// is a tradeoff.
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p->Emit({{"class", QualifiedClassName(c.second, options)}}, R"cc(
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template <>
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$dllexport_decl $$class$* Arena::CreateMaybeMessage<$class$>(Arena*);
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)cc");
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}
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}
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}
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‎src/google/protobuf/compiler/cpp/helpers.h‎

Lines changed: 8 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1008,6 +1008,14 @@ void GenerateUtf8CheckCodeForCord(io::Printer* p, const FieldDescriptor* field,
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const Options& options, bool for_parse,
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absl::string_view parameters);
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1011+
inline bool ShouldGenerateExternSpecializations(const Options& options) {
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// For OSS we omit the specializations to reduce codegen size.
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// Some compilers can't handle that much input in a single translation unit.
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// These specializations are just a link size optimization and do not affect
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// correctness or performance, so it is ok to omit them.
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return !options.opensource_runtime;
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}
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10111019
struct OneOfRangeImpl {
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struct Iterator {
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using iterator_category = std::forward_iterator_tag;

‎src/google/protobuf/compiler/cpp/message.cc‎

Lines changed: 8 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -2953,12 +2953,14 @@ void MessageGenerator::GenerateSourceInProto2Namespace(io::Printer* p) {
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auto v = p->WithVars(ClassVars(descriptor_, options_));
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auto t = p->WithVars(MakeTrackerCalls(descriptor_, options_));
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Formatter format(p);
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format(
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"template<> "
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"PROTOBUF_NOINLINE $classtype$*\n"
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"Arena::CreateMaybeMessage< $classtype$ >(Arena* arena) {\n"
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" return Arena::CreateMessageInternal< $classtype$ >(arena);\n"
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"}\n");
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if (ShouldGenerateExternSpecializations(options_)) {
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format(
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"template<> "
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"PROTOBUF_NOINLINE $classtype$*\n"
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"Arena::CreateMaybeMessage< $classtype$ >(Arena* arena) {\n"
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" return Arena::CreateMessageInternal< $classtype$ >(arena);\n"
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"}\n");
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}
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}
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void MessageGenerator::GenerateClear(io::Printer* p) {

‎src/google/protobuf/compiler/plugin.pb.cc‎

Lines changed: 0 additions & 16 deletions
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‎src/google/protobuf/compiler/plugin.pb.h‎

Lines changed: 0 additions & 8 deletions
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‎src/google/protobuf/cpp_features.pb.cc‎

Lines changed: 0 additions & 4 deletions
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‎src/google/protobuf/cpp_features.pb.h‎

Lines changed: 0 additions & 2 deletions
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‎src/google/protobuf/descriptor.pb.cc‎

Lines changed: 0 additions & 120 deletions
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‎src/google/protobuf/descriptor.pb.h‎

Lines changed: 0 additions & 60 deletions
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