neoneo-go/pkg/compiler/inline.go
2021-02-25 15:12:16 +03:00

102 lines
3 KiB
Go

package compiler
import (
"go/ast"
"go/types"
"github.com/nspcc-dev/neo-go/pkg/vm/emit"
"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
)
// inlineCall inlines call of n for function represented by f.
// Call `f(a,b)` for definition `func f(x,y int)` is translated to block:
// {
// x := a
// y := b
// <inline body of f directly>
// }
func (c *codegen) inlineCall(f *funcScope, n *ast.CallExpr) {
pkg := c.buildInfo.program.Package(f.pkg.Path())
sig := c.typeOf(n.Fun).(*types.Signature)
// When inlined call is used during global initialization
// there is no func scope, thus this if.
if c.scope == nil {
c.scope = &funcScope{}
c.scope.vars.newScope()
defer func() { c.scope = nil }()
}
// Arguments need to be walked with the current scope,
// while stored in the new.
oldScope := c.scope.vars.locals
c.scope.vars.newScope()
newScope := c.scope.vars.locals
defer c.scope.vars.dropScope()
hasVarArgs := !n.Ellipsis.IsValid()
needPack := sig.Variadic() && hasVarArgs
for i := range n.Args {
c.scope.vars.locals = oldScope
// true if normal arg or var arg is `slice...`
needStore := i < sig.Params().Len()-1 || !sig.Variadic() || !hasVarArgs
if !needStore {
break
}
name := sig.Params().At(i).Name()
if tv := c.typeAndValueOf(n.Args[i]); tv.Value != nil {
c.scope.vars.locals = newScope
c.scope.vars.addAlias(name, varLocal, unspecifiedVarIndex, tv)
continue
}
if arg, ok := n.Args[i].(*ast.Ident); ok {
// When function argument is variable or const, we may avoid
// introducing additional variables for parameters.
// This is done by providing additional alias to variable.
if vi := c.scope.vars.getVarInfo(arg.Name); vi != nil {
c.scope.vars.locals = newScope
c.scope.vars.addAlias(name, vi.refType, vi.index, vi.tv)
continue
} else if arg.Name == "nil" {
c.scope.vars.locals = newScope
c.scope.vars.addAlias(name, varLocal, unspecifiedVarIndex, types.TypeAndValue{})
continue
} else if index, ok := c.globals[c.getIdentName("", arg.Name)]; ok {
c.scope.vars.locals = newScope
c.scope.vars.addAlias(name, varGlobal, index, types.TypeAndValue{})
continue
}
}
ast.Walk(c, n.Args[i])
c.scope.vars.locals = newScope
c.scope.newLocal(name)
c.emitStoreVar("", name)
}
if needPack {
// traverse variadic args and pack them
// if they are provided directly i.e. without `...`
c.scope.vars.locals = oldScope
for i := sig.Params().Len() - 1; i < len(n.Args); i++ {
ast.Walk(c, n.Args[i])
}
c.scope.vars.locals = newScope
c.packVarArgs(n, sig)
name := sig.Params().At(sig.Params().Len() - 1).Name()
c.scope.newLocal(name)
c.emitStoreVar("", name)
}
c.pkgInfoInline = append(c.pkgInfoInline, pkg)
oldMap := c.importMap
c.fillImportMap(f.file, pkg.Pkg)
ast.Inspect(f.decl, c.scope.analyzeVoidCalls)
ast.Walk(c, f.decl.Body)
if c.scope.voidCalls[n] {
for i := 0; i < f.decl.Type.Results.NumFields(); i++ {
emit.Opcodes(c.prog.BinWriter, opcode.DROP)
}
}
c.importMap = oldMap
c.pkgInfoInline = c.pkgInfoInline[:len(c.pkgInfoInline)-1]
}