.gitignore added

[dotfiles/.git] / .config / coc / extensions / coc-go-data / tools / pkg / mod / golang.org / x / tools@v0.1.0 / go / analysis / passes / unusedresult / unusedresult.go

diff --git a/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.0/go/analysis/passes/unusedresult/unusedresult.go b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.0/go/analysis/passes/unusedresult/unusedresult.go
new file mode 100644 (file)
index 0000000..bececee
--- /dev/null
+++ b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.0/go/analysis/passes/unusedresult/unusedresult.go
@@ -0,0 +1,131 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package unusedresult defines an analyzer that checks for unused
+// results of calls to certain pure functions.
+package unusedresult
+
+import (
+       "go/ast"
+       "go/token"
+       "go/types"
+       "sort"
+       "strings"
+
+       "golang.org/x/tools/go/analysis"
+       "golang.org/x/tools/go/analysis/passes/inspect"
+       "golang.org/x/tools/go/analysis/passes/internal/analysisutil"
+       "golang.org/x/tools/go/ast/inspector"
+)
+
+// TODO(adonovan): make this analysis modular: export a mustUseResult
+// fact for each function that tail-calls one of the functions that we
+// check, and check those functions too.
+
+const Doc = `check for unused results of calls to some functions
+
+Some functions like fmt.Errorf return a result and have no side effects,
+so it is always a mistake to discard the result. This analyzer reports
+calls to certain functions in which the result of the call is ignored.
+
+The set of functions may be controlled using flags.`
+
+var Analyzer = &analysis.Analyzer{
+       Name:     "unusedresult",
+       Doc:      Doc,
+       Requires: []*analysis.Analyzer{inspect.Analyzer},
+       Run:      run,
+}
+
+// flags
+var funcs, stringMethods stringSetFlag
+
+func init() {
+       // TODO(adonovan): provide a comment syntax to allow users to
+       // add their functions to this set using facts.
+       funcs.Set("errors.New,fmt.Errorf,fmt.Sprintf,fmt.Sprint,sort.Reverse,context.WithValue,context.WithCancel,context.WithDeadline,context.WithTimeout")
+       Analyzer.Flags.Var(&funcs, "funcs",
+               "comma-separated list of functions whose results must be used")
+
+       stringMethods.Set("Error,String")
+       Analyzer.Flags.Var(&stringMethods, "stringmethods",
+               "comma-separated list of names of methods of type func() string whose results must be used")
+}
+
+func run(pass *analysis.Pass) (interface{}, error) {
+       inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)
+
+       nodeFilter := []ast.Node{
+               (*ast.ExprStmt)(nil),
+       }
+       inspect.Preorder(nodeFilter, func(n ast.Node) {
+               call, ok := analysisutil.Unparen(n.(*ast.ExprStmt).X).(*ast.CallExpr)
+               if !ok {
+                       return // not a call statement
+               }
+               fun := analysisutil.Unparen(call.Fun)
+
+               if pass.TypesInfo.Types[fun].IsType() {
+                       return // a conversion, not a call
+               }
+
+               selector, ok := fun.(*ast.SelectorExpr)
+               if !ok {
+                       return // neither a method call nor a qualified ident
+               }
+
+               sel, ok := pass.TypesInfo.Selections[selector]
+               if ok && sel.Kind() == types.MethodVal {
+                       // method (e.g. foo.String())
+                       obj := sel.Obj().(*types.Func)
+                       sig := sel.Type().(*types.Signature)
+                       if types.Identical(sig, sigNoArgsStringResult) {
+                               if stringMethods[obj.Name()] {
+                                       pass.Reportf(call.Lparen, "result of (%s).%s call not used",
+                                               sig.Recv().Type(), obj.Name())
+                               }
+                       }
+               } else if !ok {
+                       // package-qualified function (e.g. fmt.Errorf)
+                       obj := pass.TypesInfo.Uses[selector.Sel]
+                       if obj, ok := obj.(*types.Func); ok {
+                               qname := obj.Pkg().Path() + "." + obj.Name()
+                               if funcs[qname] {
+                                       pass.Reportf(call.Lparen, "result of %v call not used", qname)
+                               }
+                       }
+               }
+       })
+       return nil, nil
+}
+
+// func() string
+var sigNoArgsStringResult = types.NewSignature(nil, nil,
+       types.NewTuple(types.NewVar(token.NoPos, nil, "", types.Typ[types.String])),
+       false)
+
+type stringSetFlag map[string]bool
+
+func (ss *stringSetFlag) String() string {
+       var items []string
+       for item := range *ss {
+               items = append(items, item)
+       }
+       sort.Strings(items)
+       return strings.Join(items, ",")
+}
+
+func (ss *stringSetFlag) Set(s string) error {
+       m := make(map[string]bool) // clobber previous value
+       if s != "" {
+               for _, name := range strings.Split(s, ",") {
+                       if name == "" {
+                               continue // TODO: report error? proceed?
+                       }
+                       m[name] = true
+               }
+       }
+       *ss = m
+       return nil
+}