init.go

Documentation: google.golang.org/protobuf/cmd/protoc-gen-go/internal_gengo

     1  // Copyright 2019 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package internal_gengo
     6  
     7  import (
     8  	"unicode"
     9  	"unicode/utf8"
    10  
    11  	"google.golang.org/protobuf/compiler/protogen"
    12  	"google.golang.org/protobuf/encoding/protowire"
    13  
    14  	"google.golang.org/protobuf/types/descriptorpb"
    15  )
    16  
    17  type fileInfo struct {
    18  	*protogen.File
    19  
    20  	allEnums      []*enumInfo
    21  	allMessages   []*messageInfo
    22  	allExtensions []*extensionInfo
    23  
    24  	allEnumsByPtr         map[*enumInfo]int    // value is index into allEnums
    25  	allMessagesByPtr      map[*messageInfo]int // value is index into allMessages
    26  	allMessageFieldsByPtr map[*messageInfo]*structFields
    27  
    28  	// needRawDesc specifies whether the generator should emit logic to provide
    29  	// the legacy raw descriptor in GZIP'd form.
    30  	// This is updated by enum and message generation logic as necessary,
    31  	// and checked at the end of file generation.
    32  	needRawDesc bool
    33  }
    34  
    35  type structFields struct {
    36  	count      int
    37  	unexported map[int]string
    38  }
    39  
    40  func (sf *structFields) append(name string) {
    41  	if r, _ := utf8.DecodeRuneInString(name); !unicode.IsUpper(r) {
    42  		if sf.unexported == nil {
    43  			sf.unexported = make(map[int]string)
    44  		}
    45  		sf.unexported[sf.count] = name
    46  	}
    47  	sf.count++
    48  }
    49  
    50  func newFileInfo(file *protogen.File) *fileInfo {
    51  	f := &fileInfo{File: file}
    52  
    53  	// Collect all enums, messages, and extensions in "flattened ordering".
    54  	// See filetype.TypeBuilder.
    55  	var walkMessages func([]*protogen.Message, func(*protogen.Message))
    56  	walkMessages = func(messages []*protogen.Message, f func(*protogen.Message)) {
    57  		for _, m := range messages {
    58  			f(m)
    59  			walkMessages(m.Messages, f)
    60  		}
    61  	}
    62  	initEnumInfos := func(enums []*protogen.Enum) {
    63  		for _, enum := range enums {
    64  			f.allEnums = append(f.allEnums, newEnumInfo(f, enum))
    65  		}
    66  	}
    67  	initMessageInfos := func(messages []*protogen.Message) {
    68  		for _, message := range messages {
    69  			f.allMessages = append(f.allMessages, newMessageInfo(f, message))
    70  		}
    71  	}
    72  	initExtensionInfos := func(extensions []*protogen.Extension) {
    73  		for _, extension := range extensions {
    74  			f.allExtensions = append(f.allExtensions, newExtensionInfo(f, extension))
    75  		}
    76  	}
    77  	initEnumInfos(f.Enums)
    78  	initMessageInfos(f.Messages)
    79  	initExtensionInfos(f.Extensions)
    80  	walkMessages(f.Messages, func(m *protogen.Message) {
    81  		initEnumInfos(m.Enums)
    82  		initMessageInfos(m.Messages)
    83  		initExtensionInfos(m.Extensions)
    84  	})
    85  
    86  	// Derive a reverse mapping of enum and message pointers to their index
    87  	// in allEnums and allMessages.
    88  	if len(f.allEnums) > 0 {
    89  		f.allEnumsByPtr = make(map[*enumInfo]int)
    90  		for i, e := range f.allEnums {
    91  			f.allEnumsByPtr[e] = i
    92  		}
    93  	}
    94  	if len(f.allMessages) > 0 {
    95  		f.allMessagesByPtr = make(map[*messageInfo]int)
    96  		f.allMessageFieldsByPtr = make(map[*messageInfo]*structFields)
    97  		for i, m := range f.allMessages {
    98  			f.allMessagesByPtr[m] = i
    99  			f.allMessageFieldsByPtr[m] = new(structFields)
   100  		}
   101  	}
   102  
   103  	return f
   104  }
   105  
   106  type enumInfo struct {
   107  	*protogen.Enum
   108  
   109  	genJSONMethod    bool
   110  	genRawDescMethod bool
   111  }
   112  
   113  func newEnumInfo(f *fileInfo, enum *protogen.Enum) *enumInfo {
   114  	e := &enumInfo{Enum: enum}
   115  	e.genJSONMethod = true
   116  	e.genRawDescMethod = true
   117  	return e
   118  }
   119  
   120  type messageInfo struct {
   121  	*protogen.Message
   122  
   123  	genRawDescMethod  bool
   124  	genExtRangeMethod bool
   125  
   126  	isTracked bool
   127  	hasWeak   bool
   128  }
   129  
   130  func newMessageInfo(f *fileInfo, message *protogen.Message) *messageInfo {
   131  	m := &messageInfo{Message: message}
   132  	m.genRawDescMethod = true
   133  	m.genExtRangeMethod = true
   134  	m.isTracked = isTrackedMessage(m)
   135  	for _, field := range m.Fields {
   136  		m.hasWeak = m.hasWeak || field.Desc.IsWeak()
   137  	}
   138  	return m
   139  }
   140  
   141  // isTrackedMessage reports whether field tracking is enabled on the message.
   142  func isTrackedMessage(m *messageInfo) (tracked bool) {
   143  	const trackFieldUse_fieldNumber = 37383685
   144  
   145  	// Decode the option from unknown fields to avoid a dependency on the
   146  	// annotation proto from protoc-gen-go.
   147  	b := m.Desc.Options().(*descriptorpb.MessageOptions).ProtoReflect().GetUnknown()
   148  	for len(b) > 0 {
   149  		num, typ, n := protowire.ConsumeTag(b)
   150  		b = b[n:]
   151  		if num == trackFieldUse_fieldNumber && typ == protowire.VarintType {
   152  			v, _ := protowire.ConsumeVarint(b)
   153  			tracked = protowire.DecodeBool(v)
   154  		}
   155  		m := protowire.ConsumeFieldValue(num, typ, b)
   156  		b = b[m:]
   157  	}
   158  	return tracked
   159  }
   160  
   161  type extensionInfo struct {
   162  	*protogen.Extension
   163  }
   164  
   165  func newExtensionInfo(f *fileInfo, extension *protogen.Extension) *extensionInfo {
   166  	x := &extensionInfo{Extension: extension}
   167  	return x
   168  }
   169
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