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Golang Value.IsNull方法代码示例

本文整理汇总了Golang中github.com/axw/gollvm/llvm.Value.IsNull方法的典型用法代码示例。如果您正苦于以下问题:Golang Value.IsNull方法的具体用法?Golang Value.IsNull怎么用?Golang Value.IsNull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github.com/axw/gollvm/llvm.Value的用法示例。


在下文中一共展示了Value.IsNull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: indirectFunction

// indirectFunction creates an indirect function from a
// given function and arguments, suitable for use with
// "defer" and "go".
func (c *compiler) indirectFunction(fn *LLVMValue, args []*LLVMValue) *LLVMValue {
	nilarytyp := types.NewSignature(nil, nil, nil, nil, false)
	if len(args) == 0 {
		val := fn.LLVMValue()
		ptr := c.builder.CreateExtractValue(val, 0, "")
		ctx := c.builder.CreateExtractValue(val, 1, "")
		fnval := llvm.Undef(c.types.ToLLVM(nilarytyp))
		ptr = c.builder.CreateBitCast(ptr, fnval.Type().StructElementTypes()[0], "")
		ctx = c.builder.CreateBitCast(ctx, fnval.Type().StructElementTypes()[1], "")
		fnval = c.builder.CreateInsertValue(fnval, ptr, 0, "")
		fnval = c.builder.CreateInsertValue(fnval, ctx, 1, "")
		return c.NewValue(fnval, nilarytyp)
	}

	// Check if function pointer or context pointer is global/null.
	fnval := fn.LLVMValue()
	fnptr := fnval
	var nctx int
	var fnctx llvm.Value
	var fnctxindex uint64
	var globalfn bool
	if fnptr.Type().TypeKind() == llvm.StructTypeKind {
		fnptr = c.builder.CreateExtractValue(fnval, 0, "")
		fnctx = c.builder.CreateExtractValue(fnval, 1, "")
		globalfn = !fnptr.IsAFunction().IsNil()
		if !globalfn {
			nctx++
		}
		if !fnctx.IsNull() {
			fnctxindex = uint64(nctx)
			nctx++
		}
	} else {
		// We've got a raw global function pointer. Convert to <ptr,ctx>.
		fnval = llvm.ConstNull(c.types.ToLLVM(fn.Type()))
		fnval = llvm.ConstInsertValue(fnval, fnptr, []uint32{0})
		fn = c.NewValue(fnval, fn.Type())
		fnctx = llvm.ConstExtractValue(fnval, []uint32{1})
		globalfn = true
	}

	i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
	llvmargs := make([]llvm.Value, len(args)+nctx)
	llvmargtypes := make([]llvm.Type, len(args)+nctx)
	for i, arg := range args {
		llvmargs[i+nctx] = arg.LLVMValue()
		llvmargtypes[i+nctx] = llvmargs[i+nctx].Type()
	}
	if !globalfn {
		llvmargtypes[0] = fnptr.Type()
		llvmargs[0] = fnptr
	}
	if !fnctx.IsNull() {
		llvmargtypes[fnctxindex] = fnctx.Type()
		llvmargs[fnctxindex] = fnctx
	}

	// TODO(axw) investigate an option for go statements
	// to allocate argument structure on the stack in the
	// initiator, and block until the spawned goroutine
	// has loaded the arguments from it.
	structtyp := llvm.StructType(llvmargtypes, false)
	argstruct := c.createTypeMalloc(structtyp)
	for i, llvmarg := range llvmargs {
		argptr := c.builder.CreateGEP(argstruct, []llvm.Value{
			llvm.ConstInt(llvm.Int32Type(), 0, false),
			llvm.ConstInt(llvm.Int32Type(), uint64(i), false)}, "")
		c.builder.CreateStore(llvmarg, argptr)
	}

	// Create a function that will take a pointer to a structure of the type
	// defined above, or no parameters if there are none to pass.
	fntype := llvm.FunctionType(llvm.VoidType(), []llvm.Type{argstruct.Type()}, false)
	indirectfn := llvm.AddFunction(c.module.Module, "", fntype)
	i8argstruct := c.builder.CreateBitCast(argstruct, i8ptr, "")
	currblock := c.builder.GetInsertBlock()
	c.builder.SetInsertPointAtEnd(llvm.AddBasicBlock(indirectfn, "entry"))
	argstruct = indirectfn.Param(0)
	newargs := make([]*LLVMValue, len(args))
	for i := range llvmargs[nctx:] {
		argptr := c.builder.CreateGEP(argstruct, []llvm.Value{
			llvm.ConstInt(llvm.Int32Type(), 0, false),
			llvm.ConstInt(llvm.Int32Type(), uint64(i+nctx), false)}, "")
		newargs[i] = c.NewValue(c.builder.CreateLoad(argptr, ""), args[i].Type())
	}

	// Unless we've got a global function, extract the
	// function pointer from the context.
	if !globalfn {
		fnval = llvm.Undef(fnval.Type())
		fnptrptr := c.builder.CreateGEP(argstruct, []llvm.Value{
			llvm.ConstInt(llvm.Int32Type(), 0, false),
			llvm.ConstInt(llvm.Int32Type(), 0, false)}, "")
		fnptr = c.builder.CreateLoad(fnptrptr, "")
		fnval = c.builder.CreateInsertValue(fnval, fnptr, 0, "")
	}
	if !fnctx.IsNull() {
//.........这里部分代码省略.........
开发者ID:minux,项目名称:llgo,代码行数:101,代码来源:indirect.go


注:本文中的github.com/axw/gollvm/llvm.Value.IsNull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。