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Reduced nesting in GenerateByteSize: slight readability improvements …
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…in generated code.

GenerateByteSize itself remains deeply nested, but by factoring out one part of
the loop, at least we make the part that generates UpdateByteSize a bit more
readable.

Making the callsite of MayEmitIfNonDefaultCheck less nested actually resulted
in slight readability improvements also in the generated code, namely of the
form:

@@ -10563,8 +10559,7 @@ PROTOBUF_NOINLINE void OneStringEdition:
            {
             // string data = 1;
-            cached_has_bits =
-                this_._impl_._has_bits_[0];
+            cached_has_bits = this_._impl_._has_bits_[0];
             if (cached_has_bits & 0x00000001u) {
	       total_size += 1 + ::proto2::internal::WireFormatLite::StringSize(
                                               this_._internal_data());

These readability improvements should be kept IMO -- they make the generated
protobuf C++ code slightly easier to read.

PiperOrigin-RevId: 655180880
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@tonyliaoss @copybara-github
tonyliaoss authored and copybara-github committed Jul 23, 2024
1 parent a0387c1 commit 162a740
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Showing 5 changed files with 59 additions and 61 deletions.
4 changes: 2 additions & 2 deletions editions/golden/compare_cpp_codegen_failure.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -30,9 +30,9 @@
{
- // optional int32 int32_field = 1;
+ // int32 int32_field = 1;
cached_has_bits =
this_._impl_._has_bits_[0];
cached_has_bits = this_._impl_._has_bits_[0];
if (cached_has_bits & 0x00000001u) {
total_size += ::_pbi::WireFormatLite::Int32SizePlusOne(
[ FAILED ] third_party/protobuf/editions/golden/simple_proto3.pb.cc
[ RUN ] third_party/protobuf/editions/golden/simple_proto3.pb.h
@@ @@
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2 changes: 1 addition & 1 deletion editions/golden/compare_cpp_codegen_failure.xml
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Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,7 @@
<testsuites tests="1" name="AllTests">
<testsuite name="EditionsCodegenTests">
<testcase name="third_party/protobuf/editions/golden/simple_proto3.pb.cc" status="run" result="completed" classname="DiffTest">
<failure message="Value of: third_party/protobuf/editions/golden/simple_proto3.pb.cc&#x0A;Expected: &#x0A;// Generated by the protocol buffer compiler. DO NOT EDIT!&#x0A;// NO CHECKED-IN PROTOBUF GENCODE&#x0A;// source: third_party/protobuf/editions/golden/simple_proto3.proto&#x0A;// Protobuf C++ Version: 0.20240718.0&#x0A;&#x0A;#include &quot;third_party/protobuf/editions/golden/simple_proto3.pb.h&quot;&#x0A;&#x0A;#include &lt;algorithm&gt;&#x0A;#include &lt;type_traits&gt;&#x0A;#include &quot;third_party/protobuf/io/coded_stream.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_tctable_impl.h&quot;&#x0A;#include &quot;third_party/protobuf/extension_set.h&quot;&#x0A;#include &quot;third_party/protobuf/wire_format_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/io/zero_copy_stream_impl_lite.h&quot;&#x0A;// @@protoc_insertion_point(includes)&#x0A;&#x0A;// Must be included last.&#x0A;, with the difference:&#x0A;@@ @@&#x0A; ::_pbi::TcParser::GetTable&lt;::protobuf_editions_test::golden::SimpleProto3&gt;(), // to_prefetch&#x0A; #endif // PROTOBUF_PREFETCH_PARSE_TABLE&#x0A; }, {{&#x0A;- // optional int32 int32_field = 1;&#x0A;+ // int32 int32_field = 1;&#x0A; {::_pbi::TcParser::FastV32S1,&#x0A; {8, 0, 0, PROTOBUF_FIELD_OFFSET(SimpleProto3, _impl_.int32_field_)}},&#x0A; }}, {{&#x0A; 65535, 65535&#x0A; }}, {{&#x0A;- // optional int32 int32_field = 1;&#x0A;+ // int32 int32_field = 1;&#x0A; {PROTOBUF_FIELD_OFFSET(SimpleProto3, _impl_.int32_field_), _Internal::kHasBitsOffset + 0, 0,&#x0A; (0 | ::_fl::kFcOptional | ::_fl::kInt32)},&#x0A; }},&#x0A;@@ @@&#x0A; (void)cached_has_bits;&#x0A; &#x0A; cached_has_bits = this_._impl_._has_bits_[0];&#x0A;- // optional int32 int32_field = 1;&#x0A;+ // int32 int32_field = 1;&#x0A; if (cached_has_bits &amp; 0x00000001u) {&#x0A; target = ::proto2::internal::WireFormatLite::&#x0A; WriteInt32ToArrayWithField&lt;1&gt;(&#x0A;@@ @@&#x0A; (void)cached_has_bits;&#x0A; &#x0A; {&#x0A;- // optional int32 int32_field = 1;&#x0A;+ // int32 int32_field = 1;&#x0A; cached_has_bits =&#x0A; this_._impl_._has_bits_[0];&#x0A; if (cached_has_bits &amp; 0x00000001u) {" type=""></failure>
<failure message="Value of: third_party/protobuf/editions/golden/simple_proto3.pb.cc&#x0A;Expected: &#x0A;// Generated by the protocol buffer compiler. DO NOT EDIT!&#x0A;// NO CHECKED-IN PROTOBUF GENCODE&#x0A;// source: third_party/protobuf/editions/golden/simple_proto3.proto&#x0A;// Protobuf C++ Version: 0.20240718.0&#x0A;&#x0A;#include &quot;third_party/protobuf/editions/golden/simple_proto3.pb.h&quot;&#x0A;&#x0A;#include &lt;algorithm&gt;&#x0A;#include &lt;type_traits&gt;&#x0A;#include &quot;third_party/protobuf/io/coded_stream.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_tctable_impl.h&quot;&#x0A;#include &quot;third_party/protobuf/extension_set.h&quot;&#x0A;#include &quot;third_party/protobuf/wire_format_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/io/zero_copy_stream_impl_lite.h&quot;&#x0A;// @@protoc_insertion_point(includes)&#x0A;&#x0A;// Must be included last.&#x0A;, with the difference:&#x0A;@@ @@&#x0A; ::_pbi::TcParser::GetTable&lt;::protobuf_editions_test::golden::SimpleProto3&gt;(), // to_prefetch&#x0A; #endif // PROTOBUF_PREFETCH_PARSE_TABLE&#x0A; }, {{&#x0A;- // optional int32 int32_field = 1;&#x0A;+ // int32 int32_field = 1;&#x0A; {::_pbi::TcParser::FastV32S1,&#x0A; {8, 0, 0, PROTOBUF_FIELD_OFFSET(SimpleProto3, _impl_.int32_field_)}},&#x0A; }}, {{&#x0A; 65535, 65535&#x0A; }}, {{&#x0A;- // optional int32 int32_field = 1;&#x0A;+ // int32 int32_field = 1;&#x0A; {PROTOBUF_FIELD_OFFSET(SimpleProto3, _impl_.int32_field_), _Internal::kHasBitsOffset + 0, 0,&#x0A; (0 | ::_fl::kFcOptional | ::_fl::kInt32)},&#x0A; }},&#x0A;@@ @@&#x0A; (void)cached_has_bits;&#x0A; &#x0A; cached_has_bits = this_._impl_._has_bits_[0];&#x0A;- // optional int32 int32_field = 1;&#x0A;+ // int32 int32_field = 1;&#x0A; if (cached_has_bits &amp; 0x00000001u) {&#x0A; target = ::proto2::internal::WireFormatLite::&#x0A; WriteInt32ToArrayWithField&lt;1&gt;(&#x0A;@@ @@&#x0A; (void)cached_has_bits;&#x0A; &#x0A; {&#x0A;- // optional int32 int32_field = 1;&#x0A;+ // int32 int32_field = 1;&#x0A; cached_has_bits = this_._impl_._has_bits_[0];&#x0A; if (cached_has_bits &amp; 0x00000001u) {&#x0A; total_size += ::_pbi::WireFormatLite::Int32SizePlusOne(" type=""></failure>
</testcase>
<testcase name="third_party/protobuf/editions/golden/simple_proto3.pb.h" status="run" result="completed" classname="DiffTest">
<failure message="Value of: third_party/protobuf/editions/golden/simple_proto3.pb.h&#x0A;Expected: &#x0A;// Generated by the protocol buffer compiler. DO NOT EDIT!&#x0A;// NO CHECKED-IN PROTOBUF GENCODE&#x0A;// source: third_party/protobuf/editions/golden/simple_proto3.proto&#x0A;// Protobuf C++ Version: 0.20240718.0&#x0A;&#x0A;#ifndef GOOGLE_PROTOBUF_INCLUDED_third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;#define GOOGLE_PROTOBUF_INCLUDED_third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;&#x0A;#include &lt;limits&gt;&#x0A;#include &lt;string&gt;&#x0A;#include &lt;type_traits&gt;&#x0A;#include &lt;utility&gt;&#x0A;&#x0A;#include &quot;third_party/protobuf/runtime_version.h&quot;&#x0A;#if PROTOBUF_VERSION != 20240718&#x0A;#error &quot;Protobuf C++ gencode is built with an incompatible version of&quot;&#x0A;#error &quot;Protobuf C++ headers/runtime. See&quot;&#x0A;#error &quot;https://protobuf.dev/support/cross-version-runtime-guarantee/#cpp&quot;&#x0A;#endif&#x0A;#include &quot;third_party/protobuf/io/coded_stream.h&quot;&#x0A;#include &quot;third_party/protobuf/arena.h&quot;&#x0A;#include &quot;third_party/protobuf/arenastring.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_tctable_decl.h&quot;&#x0A;#include &quot;third_party/protobuf/generated_message_util.h&quot;&#x0A;#include &quot;third_party/protobuf/metadata_lite.h&quot;&#x0A;#include &quot;third_party/protobuf/message_lite.h&quot;&#x0A;// @@protoc_insertion_point(includes)&#x0A;&#x0A;// Must be included last.&#x0A;&#x0A;#endif // GOOGLE_PROTOBUF_INCLUDED_third_5fparty_2fprotobuf_2feditions_2fgolden_2fsimple_5fproto3_2eproto_2epb_2eh&#x0A;, with the difference:&#x0A;@@ @@&#x0A; enum : int {&#x0A; kInt32FieldFieldNumber = 1,&#x0A; };&#x0A;- // optional int32 int32_field = 1;&#x0A;+ // int32 int32_field = 1;&#x0A; bool has_int32_field() const;&#x0A; void clear_int32_field() ;&#x0A; ::int32_t int32_field() const;&#x0A;@@ @@&#x0A; &#x0A; // SimpleProto3&#x0A; &#x0A;-// optional int32 int32_field = 1;&#x0A;+// int32 int32_field = 1;&#x0A; inline bool SimpleProto3::has_int32_field() const {&#x0A; bool value = (_impl_._has_bits_[0] &amp; 0x00000001u) != 0;&#x0A; return value;" type=""></failure>
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107 changes: 51 additions & 56 deletions src/google/protobuf/compiler/cpp/message.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -1213,6 +1213,55 @@ class AccessorVerifier {

} // namespace

void MessageGenerator::EmitUpdateByteSizeForField(
const FieldDescriptor* field, io::Printer* p,
int& cached_has_word_index) const {
p->Emit(
{{"comment", [&] { PrintFieldComment(Formatter{p}, field, options_); }},
{"update_byte_size_for_field",
[&] { field_generators_.get(field).GenerateByteSize(p); }},
{"update_cached_has_bits",
[&] {
if (!HasHasbit(field) || field->options().weak()) return;

int has_bit_index = has_bit_indices_[field->index()];

if (cached_has_word_index == (has_bit_index / 32)) return;

cached_has_word_index = (has_bit_index / 32);
p->Emit({{"index", cached_has_word_index}},
R"cc(
cached_has_bits = this_.$has_bits$[$index$];
)cc");
}},
{"check_if_field_present",
[&] {
if (!HasHasbit(field)) {
MayEmitIfNonDefaultCheck(p, "this_.", field);
return;
}

if (field->options().weak()) {
p->Emit("if (has_$name$())");
return;
}

int has_bit_index = has_bit_indices_[field->index()];
p->Emit(
{{"mask", absl::StrFormat("0x%08xu",
uint32_t{1} << (has_bit_index % 32))}},
"if (cached_has_bits & $mask$)");
}}},
R"cc(
$comment$;
$update_cached_has_bits$;
$check_if_field_present$ {
//~ Force newline.
$update_byte_size_for_field$;
}
)cc");
}

void MessageGenerator::GenerateFieldAccessorDefinitions(io::Printer* p) {
p->Emit("// $classname$\n\n");

Expand Down Expand Up @@ -4748,62 +4797,8 @@ void MessageGenerator::GenerateByteSize(io::Printer* p) {
// Go back and emit checks for each of the fields we
// processed.
for (const auto* field : fields) {
p->Emit(
{{"comment",
[&] {
PrintFieldComment(Formatter{p}, field,
options_);
}},
{"update_byte_size_for_field",
[&] {
field_generators_.get(field).GenerateByteSize(
p);
}},
{"update_cached_has_bits",
[&] {
if (!HasHasbit(field) ||
field->options().weak())
return;
int has_bit_index =
has_bit_indices_[field->index()];
if (cached_has_word_index ==
(has_bit_index / 32))
return;
cached_has_word_index = (has_bit_index / 32);
p->Emit({{"index", cached_has_word_index}},
R"cc(
cached_has_bits =
this_.$has_bits$[$index$];
)cc");
}},
{"check_if_field_present",
[&] {
if (!HasHasbit(field)) {
MayEmitIfNonDefaultCheck(p, "this_.", field);
return;
}

if (field->options().weak()) {
p->Emit("if (has_$name$())");
return;
}

int has_bit_index =
has_bit_indices_[field->index()];
p->Emit(
{{"mask", absl::StrFormat(
"0x%08xu",
1u << (has_bit_index % 32))}},
"if (cached_has_bits & $mask$)");
}}},
R"cc(
$comment$;
$update_cached_has_bits$;
$check_if_field_present$ {
//~ Force newline.
$update_byte_size_for_field$;
}
)cc");
EmitUpdateByteSizeForField(field, p,
cached_has_word_index);
}
}},
{"may_update_cached_has_word_index",
Expand Down
4 changes: 4 additions & 0 deletions src/google/protobuf/compiler/cpp/message.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -186,6 +186,10 @@ class MessageGenerator {
int HasWordIndex(const FieldDescriptor* field) const;
std::vector<uint32_t> RequiredFieldsBitMask() const;

// Helper function to reduce nesting levels of deep Emit calls.
void EmitUpdateByteSizeForField(const FieldDescriptor* field, io::Printer* p,
int& cached_has_word_index) const;

const Descriptor* descriptor_;
int index_in_file_messages_;
Options options_;
Expand Down
3 changes: 1 addition & 2 deletions src/google/protobuf/descriptor.pb.cc
View file

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