runtime.go

// Copyright 2012 The llgo Authors.
// Use of this source code is governed by an MIT-style
// license that can be found in the LICENSE file.

package llgo

import (
	"fmt"
	"go/ast"
	"go/build"
	"go/token"
	"path"

	"code.google.com/p/go.tools/go/types"

	"github.com/go-llvm/llvm"
)

type FuncResolver interface {
	ResolveFunc(*types.Func) *LLVMValue
}

type runtimeType struct {
	types.Type
	llvm llvm.Type
}

// runtimeInterface is a struct containing references to
// runtime types and intrinsic function declarations.
type runtimeInterface struct {
	// runtime types
	eface,
	rtype,
	uncommonType,
	arrayType,
	chanType,
	funcType,
	iface,
	imethod,
	interfaceType,
	itab,
	mapiter,
	mapType,
	method,
	ptrType,
	sliceType,
	structField,
	structType,
	defers runtimeType

	// intrinsics
	chanclose,
	chanrecv,
	chansend,
	compareE2E,
	convertE2I,
	convertE2V,
	convertI2E,
	mustConvertE2I,
	mustConvertE2V,
	eqtyp,
	Go,
	initdefers,
	stackrestore,
	stacksave,
	setjmp,
	main,
	printfloat,
	makemap,
	makechan,
	malloc,
	mapaccess,
	mapdelete,
	mapiterinit,
	mapiternext,
	maplookup,
	memcpy,
	memequal,
	memset,
	panic_,
	pushdefer,
	recover_,
	rundefers,
	chancap,
	chanlen,
	makeslice,
	maplen,
	runestostr,
	selectdefault,
	selectgo,
	selectinit,
	selectrecv,
	selectsend,
	selectsize,
	sliceappend,
	slicecopy,
	sliceslice,
	strcat,
	strcmp,
	streqalg,
	stringslice,
	strnext,
	strrune,
	strtorunes,
	f32eqalg,
	f64eqalg,
	c64eqalg,
	c128eqalg *LLVMValue
}

func newRuntimeInterface(pkg *types.Package, module llvm.Module, tm *llvmTypeMap, fr FuncResolver) (*runtimeInterface, error) {
	var ri runtimeInterface
	runtimeTypes := map[string]*runtimeType{
		"eface":         &ri.eface,
		"rtype":         &ri.rtype,
		"uncommonType":  &ri.uncommonType,
		"arrayType":     &ri.arrayType,
		"chanType":      &ri.chanType,
		"funcType":      &ri.funcType,
		"iface":         &ri.iface,
		"imethod":       &ri.imethod,
		"interfaceType": &ri.interfaceType,
		"itab":          &ri.itab,
		"mapiter":       &ri.mapiter,
		"mapType":       &ri.mapType,
		"method":        &ri.method,
		"ptrType":       &ri.ptrType,
		"sliceType":     &ri.sliceType,
		"structField":   &ri.structField,
		"structType":    &ri.structType,
		"defers":        &ri.defers,
	}
	for name, field := range runtimeTypes {
		obj := pkg.Scope().Lookup(name)
		if obj == nil {
			return nil, fmt.Errorf("no runtime type with name %s", name)
		}
		field.Type = obj.Type()
		field.llvm = tm.ToLLVM(field.Type)
	}

	intrinsics := map[string]**LLVMValue{
		"chanclose":         &ri.chanclose,
		"chanrecv":          &ri.chanrecv,
		"chansend":          &ri.chansend,
		"compareE2E":        &ri.compareE2E,
		"convertE2I":        &ri.convertE2I,
		"convertE2V":        &ri.convertE2V,
		"mustConvertE2I":    &ri.mustConvertE2I,
		"mustConvertE2V":    &ri.mustConvertE2V,
		"convertI2E":        &ri.convertI2E,
		"eqtyp":             &ri.eqtyp,
		"Go":                &ri.Go,
		"initdefers":        &ri.initdefers,
		"llvm_stackrestore": &ri.stackrestore,
		"llvm_stacksave":    &ri.stacksave,
		"llvm_setjmp":       &ri.setjmp,
		"main":              &ri.main,
		"printfloat":        &ri.printfloat,
		"makechan":          &ri.makechan,
		"makemap":           &ri.makemap,
		"malloc":            &ri.malloc,
		"mapaccess":         &ri.mapaccess,
		"mapdelete":         &ri.mapdelete,
		"mapiterinit":       &ri.mapiterinit,
		"mapiternext":       &ri.mapiternext,
		"maplookup":         &ri.maplookup,
		"memcpy":            &ri.memcpy,
		"memequal":          &ri.memequal,
		"memset":            &ri.memset,
		"panic_":            &ri.panic_,
		"pushdefer":         &ri.pushdefer,
		"recover_":          &ri.recover_,
		"rundefers":         &ri.rundefers,
		"chancap":           &ri.chancap,
		"chanlen":           &ri.chanlen,
		"maplen":            &ri.maplen,
		"makeslice":         &ri.makeslice,
		"selectdefault":     &ri.selectdefault,
		"selectgo":          &ri.selectgo,
		"selectinit":        &ri.selectinit,
		"selectrecv":        &ri.selectrecv,
		"selectsend":        &ri.selectsend,
		"selectsize":        &ri.selectsize,
		"sliceappend":       &ri.sliceappend,
		"slicecopy":         &ri.slicecopy,
		"sliceslice":        &ri.sliceslice,
		"stringslice":       &ri.stringslice,
		"strcat":            &ri.strcat,
		"strcmp":            &ri.strcmp,
		"strnext":           &ri.strnext,
		"strrune":           &ri.strrune,
		"strtorunes":        &ri.strtorunes,
		"runestostr":        &ri.runestostr,
		"streqalg":          &ri.streqalg,
		"f32eqalg":          &ri.f32eqalg,
		"f64eqalg":          &ri.f64eqalg,
		"c64eqalg":          &ri.c64eqalg,
		"c128eqalg":         &ri.c128eqalg,
	}
	for name, field := range intrinsics {
		obj := pkg.Scope().Lookup(name)
		if obj == nil {
			return nil, fmt.Errorf("no runtime function with name %s", name)
		}
		*field = fr.ResolveFunc(obj.(*types.Func))
	}
	return &ri, nil
}

// importRuntime locates the the runtime package and parses its files
// to *ast.Files. This is used to generate runtime type structures.
func parseRuntime(buildctx *build.Context, fset *token.FileSet) ([]*ast.File, error) {
	buildpkg, err := buildctx.Import("github.com/go-llvm/llgo/pkg/runtime", "", 0)
	if err != nil {
		return nil, err
	}
	filenames := make([]string, len(buildpkg.GoFiles))
	for i, f := range buildpkg.GoFiles {
		filenames[i] = path.Join(buildpkg.Dir, f)
	}
	return parseFiles(fset, filenames)
}

func (c *compiler) createMalloc(size llvm.Value) llvm.Value {
	malloc := c.runtime.malloc.LLVMValue()
	switch n := size.Type().IntTypeWidth() - c.target.IntPtrType().IntTypeWidth(); {
	case n < 0:
		size = c.builder.CreateZExt(size, c.target.IntPtrType(), "")
	case n > 0:
		size = c.builder.CreateTrunc(size, c.target.IntPtrType(), "")
	}
	return c.builder.CreateCall(malloc, []llvm.Value{size}, "")
}

func (c *compiler) createTypeMalloc(t llvm.Type) llvm.Value {
	ptr := c.createMalloc(llvm.SizeOf(t))
	return c.builder.CreateIntToPtr(ptr, llvm.PointerType(t, 0), "")
}

func (c *compiler) memsetZero(ptr llvm.Value, size llvm.Value) {
	memset := c.runtime.memset.LLVMValue()
	switch n := size.Type().IntTypeWidth() - c.target.IntPtrType().IntTypeWidth(); {
	case n < 0:
		size = c.builder.CreateZExt(size, c.target.IntPtrType(), "")
	case n > 0:
		size = c.builder.CreateTrunc(size, c.target.IntPtrType(), "")
	}
	ptr = c.builder.CreatePtrToInt(ptr, c.target.IntPtrType(), "")
	fill := llvm.ConstNull(llvm.Int8Type())
	c.builder.CreateCall(memset, []llvm.Value{ptr, fill, size}, "")
}

func (c *compiler) stacksave() llvm.Value {
	return c.builder.CreateCall(c.runtime.stacksave.LLVMValue(), nil, "")
}

func (c *compiler) stackrestore(ctx llvm.Value) {
	c.builder.CreateCall(c.runtime.stackrestore.LLVMValue(), []llvm.Value{ctx}, "")
}