Golang Value.Type方法代码示例

func directEncode(ctx llvm.Context, allocaBuilder llvm.Builder, builder llvm.Builder, argTypes []llvm.Type, args []llvm.Value, val llvm.Value) {
	valType := val.Type()

	switch len(argTypes) {
	case 0:
		// do nothing

	case 1:
		if argTypes[0].C == valType.C {
			args[0] = val
			return
		}
		alloca := allocaBuilder.CreateAlloca(valType, "")
		bitcast := builder.CreateBitCast(alloca, llvm.PointerType(argTypes[0], 0), "")
		builder.CreateStore(val, alloca)
		args[0] = builder.CreateLoad(bitcast, "")

	case 2:
		encodeType := llvm.StructType(argTypes, false)
		alloca := allocaBuilder.CreateAlloca(valType, "")
		bitcast := builder.CreateBitCast(alloca, llvm.PointerType(encodeType, 0), "")
		builder.CreateStore(val, alloca)
		args[0] = builder.CreateLoad(builder.CreateStructGEP(bitcast, 0, ""), "")
		args[1] = builder.CreateLoad(builder.CreateStructGEP(bitcast, 1, ""), "")

	default:
		panic("unexpected argTypes size")
	}
}

func (c *Codegen) generateArithmeticBinaryExpr(left, right llvm.Value, op string) llvm.Value {
	t := c.getUnderlyingType(left.Type())
	switch op {
	case "+":
		if t == PRIMITIVE_TYPES["float"] {
			return c.builder.CreateFAdd(left, right, "")
		} else if t == PRIMITIVE_TYPES["int"] {
			return c.builder.CreateAdd(left, right, "")
		} else if t == c.templates["string"].Type {
			return c.generateStringConcat(left, right)
		}
	case "-":
		if t == PRIMITIVE_TYPES["float"] {
			return c.builder.CreateFSub(left, right, "")
		} else if t == PRIMITIVE_TYPES["int"] {
			return c.builder.CreateSub(left, right, "")
		}
	case "*":
		if t == PRIMITIVE_TYPES["float"] {
			return c.builder.CreateFMul(left, right, "")
		} else if t == PRIMITIVE_TYPES["int"] {
			return c.builder.CreateMul(left, right, "")
		}
	case "/":
		if t == PRIMITIVE_TYPES["float"] {
			return c.builder.CreateFDiv(left, right, "")
		} else if t == PRIMITIVE_TYPES["int"] {
			return c.builder.CreateSDiv(left, right, "")
		}
	}

	return null
}

// getBBName returns the name (or ID if unnamed) of a basic block.
func getBBName(v llvm.Value) (string, error) {
	if !v.IsBasicBlock() {
		return "", errutil.Newf("invalid value type; expected basic block, got %v", v.Type())
	}

	// Locate the name of a named basic block.
	if name := v.Name(); len(name) > 0 {
		return name, nil
	}

	// Locate the ID of an unnamed basic block by parsing the value dump in
	// search for its basic block label.
	//
	// Example value dump:
	//    0:
	//      br i1 true, label %1, label %2
	//
	// Each basic block is expected to have a label, which requires the
	// "unnamed.patch" to be applied to the llvm.org/llvm/bindings/go/llvm code
	// base.
	s, err := hackDump(v)
	if err != nil {
		return "", errutil.Err(err)
	}
	tokens := lexer.ParseString(s)
	if len(tokens) < 1 {
		return "", errutil.Newf("unable to locate basic block label in %q", s)
	}
	tok := tokens[0]
	if tok.Kind != token.Label {
		return "", errutil.Newf("invalid token; expected %v, got %v", token.Label, tok.Kind)
	}
	return tok.Val, nil
}

func (fr *frame) createZExtOrTrunc(v llvm.Value, t llvm.Type, name string) llvm.Value {
	switch n := v.Type().IntTypeWidth() - t.IntTypeWidth(); {
	case n < 0:
		v = fr.builder.CreateZExt(v, fr.target.IntPtrType(), name)
	case n > 0:
		v = fr.builder.CreateTrunc(v, fr.target.IntPtrType(), name)
	}
	return v
}

func (c *Codegen) unbox(val llvm.Value) llvm.Value {
	t := c.getUnderlyingType(val.Type())
	switch t {
	case c.templates["string"].Type:
		val = c.builder.CreateStructGEP(val, 0, "")
		val = c.builder.CreateLoad(val, "")
	}

	return val
}

func (c *Codegen) convert(val llvm.Value, t llvm.Type) llvm.Value {
	if val.Type() == t {
		return val
	}

	if val == c.scope.GetValue("null") {
		log.Println("Null conversion")
		return llvm.ConstPointerNull(t)
	}

	switch val.Type() {
	case PRIMITIVE_TYPES["int"]:
		if t == PRIMITIVE_TYPES["float"] {
			return c.builder.CreateSIToFP(val, t, "")
		}
	}

	return val
}

// If val is a constant and addr refers to a global variable which is defined in
// this module or an element thereof, simulate the effect of storing val at addr
// in the global variable's initializer and return true, otherwise return false.
// Precondition: we are compiling the init function.
func (fr *frame) maybeStoreInInitializer(val, addr llvm.Value) bool {
	if val.IsAConstant().IsNil() {
		return false
	}

	if !addr.IsAConstantExpr().IsNil() && addr.OperandsCount() >= 2 &&
		// TODO(pcc): Explicitly check that this is a constant GEP.
		// I don't think there are any other kinds of constantexpr which
		// satisfy the conditions we test for here, so this is probably safe.
		!addr.Operand(0).IsAGlobalVariable().IsNil() &&
		addr.Operand(1).IsNull() {
		gv := addr.Operand(0)
		globalInit, ok := fr.globalInits[gv]
		if !ok {
			return false
		}
		indices := make([]uint32, addr.OperandsCount()-2)
		for i := range indices {
			op := addr.Operand(i + 2)
			if op.IsAConstantInt().IsNil() {
				return false
			}
			indices[i] = uint32(op.ZExtValue())
		}
		globalInit.update(gv.Type().ElementType(), indices, val)
		return true
	} else if !addr.IsAGlobalVariable().IsNil() {
		if globalInit, ok := fr.globalInits[addr]; ok {
			globalInit.update(addr.Type().ElementType(), nil, val)
			return true
		}
		return false
	} else {
		return false
	}
}

func (c *Codegen) generateComparisonBinaryExpr(left, right llvm.Value, op string) llvm.Value {
	t := c.getUnderlyingType(left.Type())
	if t == PRIMITIVE_TYPES["float"] {
		return c.builder.CreateFCmp(floatPredicates[op], left, right, "")
	} else if t == PRIMITIVE_TYPES["int"] || op == "==" || op == "!=" {
		log.Println("Left:", left.Type(), "Right:", right.Type())
		return c.builder.CreateICmp(intPredicates[op], left, right, "")
	}

	return null
}

func (ai *indirectArgInfo) encode(ctx llvm.Context, allocaBuilder llvm.Builder, builder llvm.Builder, args []llvm.Value, val llvm.Value) {
	alloca := allocaBuilder.CreateAlloca(val.Type(), "")
	builder.CreateStore(val, alloca)
	args[ai.argOffset] = alloca
}

func (fr *frame) instruction(instr ssa.Instruction) {
	fr.logf("[%T] %v @ %s\n", instr, instr, fr.pkg.Prog.Fset.Position(instr.Pos()))
	if fr.GenerateDebug {
		fr.debug.SetLocation(fr.builder, instr.Pos())
	}

	switch instr := instr.(type) {
	case *ssa.Alloc:
		typ := deref(instr.Type())
		llvmtyp := fr.llvmtypes.ToLLVM(typ)
		var value llvm.Value
		if !instr.Heap {
			value = fr.env[instr].value
			fr.memsetZero(value, llvm.SizeOf(llvmtyp))
		} else if fr.isInit && fr.shouldStaticallyAllocate(instr) {
			// If this is the init function and we think it may be beneficial,
			// allocate memory statically in the object file rather than on the
			// heap. This allows us to optimize constant stores into such
			// variables as static initializations.
			global := llvm.AddGlobal(fr.module.Module, llvmtyp, "")
			global.SetLinkage(llvm.InternalLinkage)
			fr.addGlobal(global, typ)
			ptr := llvm.ConstBitCast(global, llvm.PointerType(llvm.Int8Type(), 0))
			fr.env[instr] = newValue(ptr, instr.Type())
		} else {
			value = fr.createTypeMalloc(typ)
			value.SetName(instr.Comment)
			value = fr.builder.CreateBitCast(value, llvm.PointerType(llvm.Int8Type(), 0), "")
			fr.env[instr] = newValue(value, instr.Type())
		}

	case *ssa.BinOp:
		lhs, rhs := fr.value(instr.X), fr.value(instr.Y)
		fr.env[instr] = fr.binaryOp(lhs, instr.Op, rhs)

	case *ssa.Call:
		tuple := fr.callInstruction(instr)
		if len(tuple) == 1 {
			fr.env[instr] = tuple[0]
		} else {
			fr.tuples[instr] = tuple
		}

	case *ssa.ChangeInterface:
		x := fr.value(instr.X)
		// The source type must be a non-empty interface,
		// as ChangeInterface cannot fail (E2I may fail).
		if instr.Type().Underlying().(*types.Interface).NumMethods() > 0 {
			x = fr.changeInterface(x, instr.Type(), false)
		} else {
			x = fr.convertI2E(x)
		}
		fr.env[instr] = x

	case *ssa.ChangeType:
		value := fr.llvmvalue(instr.X)
		if _, ok := instr.Type().Underlying().(*types.Pointer); ok {
			value = fr.builder.CreateBitCast(value, fr.llvmtypes.ToLLVM(instr.Type()), "")
		}
		fr.env[instr] = newValue(value, instr.Type())

	case *ssa.Convert:
		v := fr.value(instr.X)
		fr.env[instr] = fr.convert(v, instr.Type())

	case *ssa.Defer:
		fn, arg := fr.createThunk(instr)
		fr.runtime.Defer.call(fr, fr.frameptr, fn, arg)

	case *ssa.Extract:
		var elem llvm.Value
		if t, ok := fr.tuples[instr.Tuple]; ok {
			elem = t[instr.Index].value
		} else {
			tuple := fr.llvmvalue(instr.Tuple)
			elem = fr.builder.CreateExtractValue(tuple, instr.Index, instr.Name())
		}
		elemtyp := instr.Type()
		fr.env[instr] = newValue(elem, elemtyp)

	case *ssa.Field:
		fieldtyp := instr.Type()
		if p, ok := fr.ptr[instr.X]; ok {
			field := fr.builder.CreateStructGEP(p, instr.Field, instr.Name())
			if fr.canAvoidElementLoad(*instr.Referrers()) {
				fr.ptr[instr] = field
			} else {
				fr.env[instr] = newValue(fr.builder.CreateLoad(field, ""), fieldtyp)
			}
		} else {
			value := fr.llvmvalue(instr.X)
			field := fr.builder.CreateExtractValue(value, instr.Field, instr.Name())
			fr.env[instr] = newValue(field, fieldtyp)
		}

	case *ssa.FieldAddr:
		ptr := fr.llvmvalue(instr.X)
		fr.nilCheck(instr.X, ptr)
		xtyp := instr.X.Type().Underlying().(*types.Pointer).Elem()
		ptrtyp := llvm.PointerType(fr.llvmtypes.ToLLVM(xtyp), 0)
//.........这里部分代码省略.........

func (v *Codegen) genBoundsCheck(limit llvm.Value, index llvm.Value, indexType parser.Type) {
	segvBlock := llvm.AddBasicBlock(v.currentLLVMFunction(), "boundscheck_segv")
	endBlock := llvm.AddBasicBlock(v.currentLLVMFunction(), "boundscheck_end")
	upperCheckBlock := llvm.AddBasicBlock(v.currentLLVMFunction(), "boundscheck_upper_block")

	tooLow := v.builder().CreateICmp(llvm.IntSGT, llvm.ConstInt(index.Type(), 0, false), index, "boundscheck_lower")
	v.builder().CreateCondBr(tooLow, segvBlock, upperCheckBlock)

	v.builder().SetInsertPointAtEnd(upperCheckBlock)

	// make sure limit and index have same width
	castedLimit := limit
	castedIndex := index
	if index.Type().IntTypeWidth() < limit.Type().IntTypeWidth() {
		if indexType.IsSigned() {
			castedIndex = v.builder().CreateSExt(index, limit.Type(), "")
		} else {
			castedIndex = v.builder().CreateZExt(index, limit.Type(), "")
		}
	} else if index.Type().IntTypeWidth() > limit.Type().IntTypeWidth() {
		castedLimit = v.builder().CreateZExt(limit, index.Type(), "")
	}

	tooHigh := v.builder().CreateICmp(llvm.IntSLE, castedLimit, castedIndex, "boundscheck_upper")
	v.builder().CreateCondBr(tooHigh, segvBlock, endBlock)

	v.builder().SetInsertPointAtEnd(segvBlock)
	v.genRaiseSegfault()
	v.builder().CreateUnreachable()

	v.builder().SetInsertPointAtEnd(endBlock)
}