.gitignore added

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

diff --git a/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.0/go/analysis/passes/errorsas/errorsas.go b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.0/go/analysis/passes/errorsas/errorsas.go
new file mode 100644 (file)
index 0000000..384f025
--- /dev/null
+++ b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.0/go/analysis/passes/errorsas/errorsas.go
@@ -0,0 +1,75 @@
+// Copyright 2018 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.
+
+// The errorsas package defines an Analyzer that checks that the second argument to
+// errors.As is a pointer to a type implementing error.
+package errorsas
+
+import (
+       "go/ast"
+       "go/types"
+
+       "golang.org/x/tools/go/analysis"
+       "golang.org/x/tools/go/analysis/passes/inspect"
+       "golang.org/x/tools/go/ast/inspector"
+       "golang.org/x/tools/go/types/typeutil"
+)
+
+const Doc = `report passing non-pointer or non-error values to errors.As
+
+The errorsas analysis reports calls to errors.As where the type
+of the second argument is not a pointer to a type implementing error.`
+
+var Analyzer = &analysis.Analyzer{
+       Name:     "errorsas",
+       Doc:      Doc,
+       Requires: []*analysis.Analyzer{inspect.Analyzer},
+       Run:      run,
+}
+
+func run(pass *analysis.Pass) (interface{}, error) {
+       switch pass.Pkg.Path() {
+       case "errors", "errors_test":
+               // These packages know how to use their own APIs.
+               // Sometimes they are testing what happens to incorrect programs.
+               return nil, nil
+       }
+
+       inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)
+
+       nodeFilter := []ast.Node{
+               (*ast.CallExpr)(nil),
+       }
+       inspect.Preorder(nodeFilter, func(n ast.Node) {
+               call := n.(*ast.CallExpr)
+               fn := typeutil.StaticCallee(pass.TypesInfo, call)
+               if fn == nil {
+                       return // not a static call
+               }
+               if len(call.Args) < 2 {
+                       return // not enough arguments, e.g. called with return values of another function
+               }
+               if fn.FullName() == "errors.As" && !pointerToInterfaceOrError(pass, call.Args[1]) {
+                       pass.ReportRangef(call, "second argument to errors.As must be a non-nil pointer to either a type that implements error, or to any interface type")
+               }
+       })
+       return nil, nil
+}
+
+var errorType = types.Universe.Lookup("error").Type().Underlying().(*types.Interface)
+
+// pointerToInterfaceOrError reports whether the type of e is a pointer to an interface or a type implementing error,
+// or is the empty interface.
+func pointerToInterfaceOrError(pass *analysis.Pass, e ast.Expr) bool {
+       t := pass.TypesInfo.Types[e].Type
+       if it, ok := t.Underlying().(*types.Interface); ok && it.NumMethods() == 0 {
+               return true
+       }
+       pt, ok := t.Underlying().(*types.Pointer)
+       if !ok {
+               return false
+       }
+       _, ok = pt.Elem().Underlying().(*types.Interface)
+       return ok || types.Implements(pt.Elem(), errorType)
+}