vikunja-api/vendor/honnef.co/go/tools/internal/passes/buildir/buildir.go
2020-05-29 22:15:21 +02:00

113 lines
3.1 KiB
Go

// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package buildir defines an Analyzer that constructs the IR
// of an error-free package and returns the set of all
// functions within it. It does not report any diagnostics itself but
// may be used as an input to other analyzers.
//
// THIS INTERFACE IS EXPERIMENTAL AND MAY BE SUBJECT TO INCOMPATIBLE CHANGE.
package buildir
import (
"go/ast"
"go/types"
"reflect"
"golang.org/x/tools/go/analysis"
"honnef.co/go/tools/ir"
)
type willExit struct{}
type willUnwind struct{}
func (*willExit) AFact() {}
func (*willUnwind) AFact() {}
var Analyzer = &analysis.Analyzer{
Name: "buildir",
Doc: "build IR for later passes",
Run: run,
ResultType: reflect.TypeOf(new(IR)),
FactTypes: []analysis.Fact{new(willExit), new(willUnwind)},
}
// IR provides intermediate representation for all the
// non-blank source functions in the current package.
type IR struct {
Pkg *ir.Package
SrcFuncs []*ir.Function
}
func run(pass *analysis.Pass) (interface{}, error) {
// Plundered from ssautil.BuildPackage.
// We must create a new Program for each Package because the
// analysis API provides no place to hang a Program shared by
// all Packages. Consequently, IR Packages and Functions do not
// have a canonical representation across an analysis session of
// multiple packages. This is unlikely to be a problem in
// practice because the analysis API essentially forces all
// packages to be analysed independently, so any given call to
// Analysis.Run on a package will see only IR objects belonging
// to a single Program.
mode := ir.GlobalDebug
prog := ir.NewProgram(pass.Fset, mode)
// Create IR packages for all imports.
// Order is not significant.
created := make(map[*types.Package]bool)
var createAll func(pkgs []*types.Package)
createAll = func(pkgs []*types.Package) {
for _, p := range pkgs {
if !created[p] {
created[p] = true
irpkg := prog.CreatePackage(p, nil, nil, true)
for _, fn := range irpkg.Functions {
if ast.IsExported(fn.Name()) {
var exit willExit
var unwind willUnwind
if pass.ImportObjectFact(fn.Object(), &exit) {
fn.WillExit = true
}
if pass.ImportObjectFact(fn.Object(), &unwind) {
fn.WillUnwind = true
}
}
}
createAll(p.Imports())
}
}
}
createAll(pass.Pkg.Imports())
// Create and build the primary package.
irpkg := prog.CreatePackage(pass.Pkg, pass.Files, pass.TypesInfo, false)
irpkg.Build()
// Compute list of source functions, including literals,
// in source order.
var addAnons func(f *ir.Function)
funcs := make([]*ir.Function, len(irpkg.Functions))
copy(funcs, irpkg.Functions)
addAnons = func(f *ir.Function) {
for _, anon := range f.AnonFuncs {
funcs = append(funcs, anon)
addAnons(anon)
}
}
for _, fn := range irpkg.Functions {
addAnons(fn)
if fn.WillExit {
pass.ExportObjectFact(fn.Object(), new(willExit))
}
if fn.WillUnwind {
pass.ExportObjectFact(fn.Object(), new(willUnwind))
}
}
return &IR{Pkg: irpkg, SrcFuncs: funcs}, nil
}