Ejemplo n.º 1
0
func grindFunc(ctxt *grinder.Context, pkg *grinder.Package, edit *grinder.EditBuffer, fn *ast.FuncDecl) {
	if fn.Body == nil {
		return
	}
	blocks := block.Build(pkg.FileSet, fn.Body)
	ast.Inspect(fn.Body, func(x ast.Node) bool {
		var list []ast.Stmt
		switch x := x.(type) {
		default:
			return true
		case *ast.BlockStmt:
			list = x.List
		case *ast.CommClause:
			list = x.Body
		case *ast.CaseClause:
			list = x.Body
		}

		for i := 0; i < len(list); i++ {
			x := list[i]
			if grinder.IsTerminatingStmt(blocks, x) {
				end := i + 1
				for end < len(list) && !isGotoTarget(blocks, list[end]) {
					end++
				}
				if end > i+1 {
					edit.Delete(edit.End(x), edit.End(list[end-1]))
					i = end - 1 // after i++, next iteration starts at end
				}
			}
		}
		return true
	})
}
Ejemplo n.º 2
0
func grindFunc(ctxt *grinder.Context, pkg *grinder.Package, edit *grinder.EditBuffer, fn *ast.FuncDecl) {
	if fn.Name.Name == "evconst" {
		old := debug
		debug = true
		defer func() { debug = old }()
	}

	if pkg.TypesError != nil {
		// Without scoping information, we can't be sure code moves are okay.
		fmt.Printf("%s: cannot inline gotos without type information\n", fn.Name)
		return
	}

	if fn.Body == nil {
		return
	}
	blocks := block.Build(pkg.FileSet, fn.Body)
	for labelname, gotos := range blocks.Goto {
		target, ok := findTargetBlock(pkg, edit, fn, blocks, labelname)
		if debug {
			println("TARGET", ok, labelname, len(gotos), target.dead, target.short)
		}
		if ok && (len(gotos) == 1 && target.dead || target.short) {
			numReplaced := 0
			for _, g := range gotos {
				code := edit.TextAt(target.comment, target.start) + target.code
				if !objsMatch(pkg, fn, g.Pos(), target.objs, target.start, target.end) {
					if debug {
						println("OBJS DO NOT MATCH")
					}
					// Cannot inline code here; needed identifiers have different meanings.
					continue
				}
				if target.needReturn {
					// NOTE: Should really check to see if function results are shadowed.
					// If we screw up, the code won't compile, so we can put it off.
					code += "; return"
				}
				if target.needGoto != "" {
					code += "; goto " + target.needGoto
				}
				edit.Replace(g.Pos(), g.End(), code)
				numReplaced++
			}
			if numReplaced == len(gotos) {
				if len(gotos) == 1 && target.dead {
					edit.Delete(target.comment, target.end)
				} else {
					edit.DeleteLine(target.start, target.endLabel)
				}
			}
			// The code we move might itself have gotos to inline,
			// and we can't make that change until we get new line
			// number position, so return after each label change.
			if numReplaced > 0 {
				return
			}
		}
	}
}