go.uber.org/yarpc@v1.72.1/encoding/protobuf/protoc-gen-yarpc-go/main.go (about)

     1  // Copyright (c) 2022 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  /*
    22  Package main provides a protoc plugin that generates code for the protobuf encoding for YARPC.
    23  
    24  To use:
    25  	go get github.com/gogo/protobuf/protoc-gen-gogoslick
    26  	go get go.uber.org/yarpc/encoding/protobuf/protoc-gen-yarpc-go
    27  	protoc --gogoslick_out=. foo.proto
    28  	protoc --yarpc-go_out=. foo.proto
    29  */
    30  package main
    31  
    32  // Note there is some crazy bug with protobuf that if you declare:
    33  //
    34  //   func bar() (kv.GetValueResponse, error) {
    35  //     return nil, errors.New("nil response and non-nil error")
    36  //   }
    37  //
    38  //   func foo() (proto.Message, error) {
    39  //     return bar()
    40  //   }
    41  //
    42  //   response, err := foo()
    43  //   fmt.Printf("%v %v\n", response, response == nil)
    44  //
    45  // This will print "<nil>, false". If you try to do something with response (ie call a function on it),
    46  // if will panic because response is nil. Something similar happens in golang/protobuf
    47  // too, so this is insane. If in bar(), you do response == nil, it will be true.
    48  // The generated code handles this.
    49  
    50  import (
    51  	"log"
    52  	"os"
    53  
    54  	"go.uber.org/yarpc/encoding/protobuf/protoc-gen-yarpc-go/internal/lib"
    55  	"go.uber.org/yarpc/internal/protoplugin"
    56  )
    57  
    58  func main() {
    59  	if err := protoplugin.Do(lib.Runner, os.Stdin, os.Stdout); err != nil {
    60  		log.Fatal(err)
    61  	}
    62  }