diff options
Diffstat (limited to 'vendor/github.com/golang/protobuf/protoc-gen-go/generator/internal/remap/remap.go')
-rw-r--r-- | vendor/github.com/golang/protobuf/protoc-gen-go/generator/internal/remap/remap.go | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/generator/internal/remap/remap.go b/vendor/github.com/golang/protobuf/protoc-gen-go/generator/internal/remap/remap.go new file mode 100644 index 0000000..a9b6103 --- /dev/null +++ b/vendor/github.com/golang/protobuf/protoc-gen-go/generator/internal/remap/remap.go @@ -0,0 +1,117 @@ +// Go support for Protocol Buffers - Google's data interchange format +// +// Copyright 2017 The Go Authors. All rights reserved. +// https://github.com/golang/protobuf +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +/* +Package remap handles tracking the locations of Go tokens in a source text +across a rewrite by the Go formatter. +*/ +package remap + +import ( + "fmt" + "go/scanner" + "go/token" +) + +// A Location represents a span of byte offsets in the source text. +type Location struct { + Pos, End int // End is exclusive +} + +// A Map represents a mapping between token locations in an input source text +// and locations in the correspnding output text. +type Map map[Location]Location + +// Find reports whether the specified span is recorded by m, and if so returns +// the new location it was mapped to. If the input span was not found, the +// returned location is the same as the input. +func (m Map) Find(pos, end int) (Location, bool) { + key := Location{ + Pos: pos, + End: end, + } + if loc, ok := m[key]; ok { + return loc, true + } + return key, false +} + +func (m Map) add(opos, oend, npos, nend int) { + m[Location{Pos: opos, End: oend}] = Location{Pos: npos, End: nend} +} + +// Compute constructs a location mapping from input to output. An error is +// reported if any of the tokens of output cannot be mapped. +func Compute(input, output []byte) (Map, error) { + itok := tokenize(input) + otok := tokenize(output) + if len(itok) != len(otok) { + return nil, fmt.Errorf("wrong number of tokens, %d ≠ %d", len(itok), len(otok)) + } + m := make(Map) + for i, ti := range itok { + to := otok[i] + if ti.Token != to.Token { + return nil, fmt.Errorf("token %d type mismatch: %s ≠ %s", i+1, ti, to) + } + m.add(ti.pos, ti.end, to.pos, to.end) + } + return m, nil +} + +// tokinfo records the span and type of a source token. +type tokinfo struct { + pos, end int + token.Token +} + +func tokenize(src []byte) []tokinfo { + fs := token.NewFileSet() + var s scanner.Scanner + s.Init(fs.AddFile("src", fs.Base(), len(src)), src, nil, scanner.ScanComments) + var info []tokinfo + for { + pos, next, lit := s.Scan() + switch next { + case token.SEMICOLON: + continue + } + info = append(info, tokinfo{ + pos: int(pos - 1), + end: int(pos + token.Pos(len(lit)) - 1), + Token: next, + }) + if next == token.EOF { + break + } + } + return info +} |