embedcheck.go

Documentation: github.com/gogo/protobuf/plugin/embedcheck

     1  // Protocol Buffers for Go with Gadgets
     2  //
     3  // Copyright (c) 2013, The GoGo Authors. All rights reserved.
     4  // http://github.com/gogo/protobuf
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     6  // Redistribution and use in source and binary forms, with or without
     7  // modification, are permitted provided that the following conditions are
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    11  // notice, this list of conditions and the following disclaimer.
    12  //     * Redistributions in binary form must reproduce the above
    13  // copyright notice, this list of conditions and the following disclaimer
    14  // in the documentation and/or other materials provided with the
    15  // distribution.
    16  //
    17  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    18  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    19  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    20  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    21  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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    23  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    24  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    25  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    26  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    27  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    28  
    29  /*
    30  The embedcheck plugin is used to check whether embed is not used incorrectly.
    31  For instance:
    32  An embedded message has a generated string method, but the is a member of a message which does not.
    33  This causes a warning.
    34  An error is caused by a namespace conflict.
    35  
    36  It is enabled by the following extensions:
    37  
    38    - embed
    39    - embed_all
    40  
    41  For incorrect usage of embed with tests see:
    42  
    43    github.com/gogo/protobuf/test/embedconflict
    44  
    45  */
    46  package embedcheck
    47  
    48  import (
    49  	"fmt"
    50  	"os"
    51  
    52  	"github.com/gogo/protobuf/gogoproto"
    53  	"github.com/gogo/protobuf/protoc-gen-gogo/generator"
    54  )
    55  
    56  type plugin struct {
    57  	*generator.Generator
    58  }
    59  
    60  func NewPlugin() *plugin {
    61  	return &plugin{}
    62  }
    63  
    64  func (p *plugin) Name() string {
    65  	return "embedcheck"
    66  }
    67  
    68  func (p *plugin) Init(g *generator.Generator) {
    69  	p.Generator = g
    70  }
    71  
    72  var overwriters []map[string]gogoproto.EnableFunc = []map[string]gogoproto.EnableFunc{
    73  	{
    74  		"stringer": gogoproto.IsStringer,
    75  	},
    76  	{
    77  		"gostring": gogoproto.HasGoString,
    78  	},
    79  	{
    80  		"equal": gogoproto.HasEqual,
    81  	},
    82  	{
    83  		"verboseequal": gogoproto.HasVerboseEqual,
    84  	},
    85  	{
    86  		"size":       gogoproto.IsSizer,
    87  		"protosizer": gogoproto.IsProtoSizer,
    88  	},
    89  	{
    90  		"unmarshaler":        gogoproto.IsUnmarshaler,
    91  		"unsafe_unmarshaler": gogoproto.IsUnsafeUnmarshaler,
    92  	},
    93  	{
    94  		"marshaler":        gogoproto.IsMarshaler,
    95  		"unsafe_marshaler": gogoproto.IsUnsafeMarshaler,
    96  	},
    97  }
    98  
    99  func (p *plugin) Generate(file *generator.FileDescriptor) {
   100  	for _, msg := range file.Messages() {
   101  		for _, os := range overwriters {
   102  			possible := true
   103  			for _, overwriter := range os {
   104  				if overwriter(file.FileDescriptorProto, msg.DescriptorProto) {
   105  					possible = false
   106  				}
   107  			}
   108  			if possible {
   109  				p.checkOverwrite(msg, os)
   110  			}
   111  		}
   112  		p.checkNameSpace(msg)
   113  		for _, field := range msg.GetField() {
   114  			if gogoproto.IsEmbed(field) && gogoproto.IsCustomName(field) {
   115  				fmt.Fprintf(os.Stderr, "ERROR: field %v with custom name %v cannot be embedded", *field.Name, gogoproto.GetCustomName(field))
   116  				os.Exit(1)
   117  			}
   118  		}
   119  		p.checkRepeated(msg)
   120  	}
   121  	for _, e := range file.GetExtension() {
   122  		if gogoproto.IsEmbed(e) {
   123  			fmt.Fprintf(os.Stderr, "ERROR: extended field %v cannot be embedded", generator.CamelCase(*e.Name))
   124  			os.Exit(1)
   125  		}
   126  	}
   127  }
   128  
   129  func (p *plugin) checkNameSpace(message *generator.Descriptor) map[string]bool {
   130  	ccTypeName := generator.CamelCaseSlice(message.TypeName())
   131  	names := make(map[string]bool)
   132  	for _, field := range message.Field {
   133  		fieldname := generator.CamelCase(*field.Name)
   134  		if field.IsMessage() && gogoproto.IsEmbed(field) {
   135  			desc := p.ObjectNamed(field.GetTypeName())
   136  			moreNames := p.checkNameSpace(desc.(*generator.Descriptor))
   137  			for another := range moreNames {
   138  				if names[another] {
   139  					fmt.Fprintf(os.Stderr, "ERROR: duplicate embedded fieldname %v in type %v\n", fieldname, ccTypeName)
   140  					os.Exit(1)
   141  				}
   142  				names[another] = true
   143  			}
   144  		} else {
   145  			if names[fieldname] {
   146  				fmt.Fprintf(os.Stderr, "ERROR: duplicate embedded fieldname %v in type %v\n", fieldname, ccTypeName)
   147  				os.Exit(1)
   148  			}
   149  			names[fieldname] = true
   150  		}
   151  	}
   152  	return names
   153  }
   154  
   155  func (p *plugin) checkOverwrite(message *generator.Descriptor, enablers map[string]gogoproto.EnableFunc) {
   156  	ccTypeName := generator.CamelCaseSlice(message.TypeName())
   157  	names := []string{}
   158  	for name := range enablers {
   159  		names = append(names, name)
   160  	}
   161  	for _, field := range message.Field {
   162  		if field.IsMessage() && gogoproto.IsEmbed(field) {
   163  			fieldname := generator.CamelCase(*field.Name)
   164  			desc := p.ObjectNamed(field.GetTypeName())
   165  			msg := desc.(*generator.Descriptor)
   166  			for errStr, enabled := range enablers {
   167  				if enabled(msg.File().FileDescriptorProto, msg.DescriptorProto) {
   168  					fmt.Fprintf(os.Stderr, "WARNING: found non-%v %v with embedded %v %v\n", names, ccTypeName, errStr, fieldname)
   169  				}
   170  			}
   171  			p.checkOverwrite(msg, enablers)
   172  		}
   173  	}
   174  }
   175  
   176  func (p *plugin) checkRepeated(message *generator.Descriptor) {
   177  	ccTypeName := generator.CamelCaseSlice(message.TypeName())
   178  	for _, field := range message.Field {
   179  		if !gogoproto.IsEmbed(field) {
   180  			continue
   181  		}
   182  		if field.IsBytes() {
   183  			fieldname := generator.CamelCase(*field.Name)
   184  			fmt.Fprintf(os.Stderr, "ERROR: found embedded bytes field %s in message %s\n", fieldname, ccTypeName)
   185  			os.Exit(1)
   186  		}
   187  		if !field.IsRepeated() {
   188  			continue
   189  		}
   190  		fieldname := generator.CamelCase(*field.Name)
   191  		fmt.Fprintf(os.Stderr, "ERROR: found repeated embedded field %s in message %s\n", fieldname, ccTypeName)
   192  		os.Exit(1)
   193  	}
   194  }
   195  
   196  func (p *plugin) GenerateImports(*generator.FileDescriptor) {}
   197  
   198  func init() {
   199  	generator.RegisterPlugin(NewPlugin())
   200  }
   201
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