X-Git-Url: https://git.josue.xyz/?a=blobdiff_plain;f=.config%2Fcoc%2Fextensions%2Fcoc-go-data%2Ftools%2Fpkg%2Fmod%2Fgolang.org%2Fx%2Ftools%40v0.0.0-20201105173854-bc9fc8d8c4bc%2Fgo%2Fanalysis%2Fpasses%2Fshift%2Fshift.go;fp=.config%2Fcoc%2Fextensions%2Fcoc-go-data%2Ftools%2Fpkg%2Fmod%2Fgolang.org%2Fx%2Ftools%40v0.0.0-20201105173854-bc9fc8d8c4bc%2Fgo%2Fanalysis%2Fpasses%2Fshift%2Fshift.go;h=1f3df07ccd1fabea0ada98583ba268d13fb90843;hb=4d07c77cf4d78cab8639e13ddc3c22495e585b0b;hp=0000000000000000000000000000000000000000;hpb=b3950616b54221c40a7dab9099bda675007e5b6e;p=dotfiles%2F.git

diff --git a/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201105173854-bc9fc8d8c4bc/go/analysis/passes/shift/shift.go b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201105173854-bc9fc8d8c4bc/go/analysis/passes/shift/shift.go
new file mode 100644
index 00000000..1f3df07c
--- /dev/null
+++ b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201105173854-bc9fc8d8c4bc/go/analysis/passes/shift/shift.go
@@ -0,0 +1,101 @@
+// Copyright 2014 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 shift defines an Analyzer that checks for shifts that exceed
+// the width of an integer.
+package shift
+
+// TODO(adonovan): integrate with ctrflow (CFG-based) dead code analysis. May
+// have impedance mismatch due to its (non-)treatment of constant
+// expressions (such as runtime.GOARCH=="386").
+
+import (
+	"go/ast"
+	"go/constant"
+	"go/token"
+
+	"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"
+)
+
+const Doc = "check for shifts that equal or exceed the width of the integer"
+
+var Analyzer = &analysis.Analyzer{
+	Name:     "shift",
+	Doc:      Doc,
+	Requires: []*analysis.Analyzer{inspect.Analyzer},
+	Run:      run,
+}
+
+func run(pass *analysis.Pass) (interface{}, error) {
+	inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)
+
+	// Do a complete pass to compute dead nodes.
+	dead := make(map[ast.Node]bool)
+	nodeFilter := []ast.Node{
+		(*ast.IfStmt)(nil),
+		(*ast.SwitchStmt)(nil),
+	}
+	inspect.Preorder(nodeFilter, func(n ast.Node) {
+		// TODO(adonovan): move updateDead into this file.
+		updateDead(pass.TypesInfo, dead, n)
+	})
+
+	nodeFilter = []ast.Node{
+		(*ast.AssignStmt)(nil),
+		(*ast.BinaryExpr)(nil),
+	}
+	inspect.Preorder(nodeFilter, func(node ast.Node) {
+		if dead[node] {
+			// Skip shift checks on unreachable nodes.
+			return
+		}
+
+		switch node := node.(type) {
+		case *ast.BinaryExpr:
+			if node.Op == token.SHL || node.Op == token.SHR {
+				checkLongShift(pass, node, node.X, node.Y)
+			}
+		case *ast.AssignStmt:
+			if len(node.Lhs) != 1 || len(node.Rhs) != 1 {
+				return
+			}
+			if node.Tok == token.SHL_ASSIGN || node.Tok == token.SHR_ASSIGN {
+				checkLongShift(pass, node, node.Lhs[0], node.Rhs[0])
+			}
+		}
+	})
+	return nil, nil
+}
+
+// checkLongShift checks if shift or shift-assign operations shift by more than
+// the length of the underlying variable.
+func checkLongShift(pass *analysis.Pass, node ast.Node, x, y ast.Expr) {
+	if pass.TypesInfo.Types[x].Value != nil {
+		// Ignore shifts of constants.
+		// These are frequently used for bit-twiddling tricks
+		// like ^uint(0) >> 63 for 32/64 bit detection and compatibility.
+		return
+	}
+
+	v := pass.TypesInfo.Types[y].Value
+	if v == nil {
+		return
+	}
+	amt, ok := constant.Int64Val(v)
+	if !ok {
+		return
+	}
+	t := pass.TypesInfo.Types[x].Type
+	if t == nil {
+		return
+	}
+	size := 8 * pass.TypesSizes.Sizeof(t)
+	if amt >= size {
+		ident := analysisutil.Format(pass.Fset, x)
+		pass.ReportRangef(node, "%s (%d bits) too small for shift of %d", ident, size, amt)
+	}
+}