当前位置: 首页>>代码示例>>Golang>>正文


Golang Value.IsNil方法代码示例

本文整理汇总了Golang中code/google/com/p/go/tools/ssa.Value.IsNil方法的典型用法代码示例。如果您正苦于以下问题:Golang Value.IsNil方法的具体用法?Golang Value.IsNil怎么用?Golang Value.IsNil使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在code/google/com/p/go/tools/ssa.Value的用法示例。


在下文中一共展示了Value.IsNil方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的Golang代码示例。

示例1: objectNode

// objectNode returns the object to which v points, if known.
// In other words, if the points-to set of v is a singleton, it
// returns the sole label, zero otherwise.
//
// We exploit this information to make the generated constraints less
// dynamic.  For example, a complex load constraint can be replaced by
// a simple copy constraint when the sole destination is known a priori.
//
// Some SSA instructions always have singletons points-to sets:
// 	Alloc, Function, Global, MakeChan, MakeClosure,  MakeInterface,  MakeMap,  MakeSlice.
// Others may be singletons depending on their operands:
// 	Capture, Const, Convert, FieldAddr, IndexAddr, Slice.
//
// Idempotent.  Objects are created as needed, possibly via recursion
// down the SSA value graph, e.g IndexAddr(FieldAddr(Alloc))).
//
func (a *analysis) objectNode(cgn *cgnode, v ssa.Value) nodeid {
	if cgn == nil {
		// Global object.
		obj, ok := a.globalobj[v]
		if !ok {
			switch v := v.(type) {
			case *ssa.Global:
				obj = a.nextNode()
				a.addNodes(mustDeref(v.Type()), "global")
				a.endObject(obj, nil, v)

			case *ssa.Function:
				obj = a.makeFunctionObject(v, nil)

			case *ssa.Const:
				if t, ok := v.Type().Underlying().(*types.Slice); ok && !v.IsNil() {
					// Non-nil []byte or []rune constant.
					obj = a.nextNode()
					a.addNodes(sliceToArray(t), "array in slice constant")
					a.endObject(obj, nil, v)
				}

			case *ssa.Capture:
				// For now, Captures have the same cardinality as globals.
				// TODO(adonovan): treat captures context-sensitively.
			}

			if a.log != nil {
				fmt.Fprintf(a.log, "\tglobalobj[%s] = n%d\n", v, obj)
			}
			a.globalobj[v] = obj
		}
		return obj
	}

	// Local object.
	obj, ok := a.localobj[v]
	if !ok {
		switch v := v.(type) {
		case *ssa.Alloc:
			obj = a.nextNode()
			a.addNodes(mustDeref(v.Type()), "alloc")
			a.endObject(obj, cgn, v)

		case *ssa.MakeSlice:
			obj = a.nextNode()
			a.addNodes(sliceToArray(v.Type()), "makeslice")
			a.endObject(obj, cgn, v)

		case *ssa.MakeChan:
			obj = a.nextNode()
			a.addNodes(v.Type().Underlying().(*types.Chan).Elem(), "makechan")
			a.endObject(obj, cgn, v)

		case *ssa.MakeMap:
			obj = a.nextNode()
			tmap := v.Type().Underlying().(*types.Map)
			a.addNodes(tmap.Key(), "makemap.key")
			a.addNodes(tmap.Elem(), "makemap.value")
			a.endObject(obj, cgn, v)

		case *ssa.MakeInterface:
			tConc := v.X.Type()
			obj = a.makeTagged(tConc, cgn, v)

			// Copy the value into it, if nontrivial.
			if x := a.valueNode(v.X); x != 0 {
				a.copy(obj+1, x, a.sizeof(tConc))
			}

		case *ssa.FieldAddr:
			if xobj := a.objectNode(cgn, v.X); xobj != 0 {
				obj = xobj + nodeid(a.offsetOf(mustDeref(v.X.Type()), v.Field))
			}

		case *ssa.IndexAddr:
			if xobj := a.objectNode(cgn, v.X); xobj != 0 {
				obj = xobj + 1
			}

		case *ssa.Slice:
			obj = a.objectNode(cgn, v.X)

		case *ssa.Convert:
//.........这里部分代码省略.........
开发者ID:amulyas,项目名称:bosh-cloudstack-cpi,代码行数:101,代码来源:gen.go


注:本文中的code/google/com/p/go/tools/ssa.Value.IsNil方法示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。