1// Copyright 2015 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5package ssautil 6 7// This file defines utility functions for constructing programs in SSA form. 8 9import ( 10 "go/ast" 11 "go/token" 12 "go/types" 13 14 "golang.org/x/tools/go/loader" 15 "golang.org/x/tools/go/packages" 16 "golang.org/x/tools/go/ssa" 17) 18 19// Packages creates an SSA program for a set of packages. 20// 21// The packages must have been loaded from source syntax using the 22// golang.org/x/tools/go/packages.Load function in LoadSyntax or 23// LoadAllSyntax mode. 24// 25// Packages creates an SSA package for each well-typed package in the 26// initial list, plus all their dependencies. The resulting list of 27// packages corresponds to the list of initial packages, and may contain 28// a nil if SSA code could not be constructed for the corresponding initial 29// package due to type errors. 30// 31// Code for bodies of functions is not built until Build is called on 32// the resulting Program. SSA code is constructed only for the initial 33// packages with well-typed syntax trees. 34// 35// The mode parameter controls diagnostics and checking during SSA construction. 36// 37func Packages(initial []*packages.Package, mode ssa.BuilderMode) (*ssa.Program, []*ssa.Package) { 38 return doPackages(initial, mode, false) 39} 40 41// AllPackages creates an SSA program for a set of packages plus all 42// their dependencies. 43// 44// The packages must have been loaded from source syntax using the 45// golang.org/x/tools/go/packages.Load function in LoadAllSyntax mode. 46// 47// AllPackages creates an SSA package for each well-typed package in the 48// initial list, plus all their dependencies. The resulting list of 49// packages corresponds to the list of initial packages, and may contain 50// a nil if SSA code could not be constructed for the corresponding 51// initial package due to type errors. 52// 53// Code for bodies of functions is not built until Build is called on 54// the resulting Program. SSA code is constructed for all packages with 55// well-typed syntax trees. 56// 57// The mode parameter controls diagnostics and checking during SSA construction. 58// 59func AllPackages(initial []*packages.Package, mode ssa.BuilderMode) (*ssa.Program, []*ssa.Package) { 60 return doPackages(initial, mode, true) 61} 62 63func doPackages(initial []*packages.Package, mode ssa.BuilderMode, deps bool) (*ssa.Program, []*ssa.Package) { 64 65 var fset *token.FileSet 66 if len(initial) > 0 { 67 fset = initial[0].Fset 68 } 69 70 prog := ssa.NewProgram(fset, mode) 71 72 isInitial := make(map[*packages.Package]bool, len(initial)) 73 for _, p := range initial { 74 isInitial[p] = true 75 } 76 77 ssamap := make(map[*packages.Package]*ssa.Package) 78 packages.Visit(initial, nil, func(p *packages.Package) { 79 if p.Types != nil && !p.IllTyped { 80 var files []*ast.File 81 if deps || isInitial[p] { 82 files = p.Syntax 83 } 84 ssamap[p] = prog.CreatePackage(p.Types, files, p.TypesInfo, true) 85 } 86 }) 87 88 var ssapkgs []*ssa.Package 89 for _, p := range initial { 90 ssapkgs = append(ssapkgs, ssamap[p]) // may be nil 91 } 92 return prog, ssapkgs 93} 94 95// CreateProgram returns a new program in SSA form, given a program 96// loaded from source. An SSA package is created for each transitively 97// error-free package of lprog. 98// 99// Code for bodies of functions is not built until Build is called 100// on the result. 101// 102// The mode parameter controls diagnostics and checking during SSA construction. 103// 104// Deprecated: Use golang.org/x/tools/go/packages and the Packages 105// function instead; see ssa.ExampleLoadPackages. 106// 107func CreateProgram(lprog *loader.Program, mode ssa.BuilderMode) *ssa.Program { 108 prog := ssa.NewProgram(lprog.Fset, mode) 109 110 for _, info := range lprog.AllPackages { 111 if info.TransitivelyErrorFree { 112 prog.CreatePackage(info.Pkg, info.Files, &info.Info, info.Importable) 113 } 114 } 115 116 return prog 117} 118 119// BuildPackage builds an SSA program with IR for a single package. 120// 121// It populates pkg by type-checking the specified file ASTs. All 122// dependencies are loaded using the importer specified by tc, which 123// typically loads compiler export data; SSA code cannot be built for 124// those packages. BuildPackage then constructs an ssa.Program with all 125// dependency packages created, and builds and returns the SSA package 126// corresponding to pkg. 127// 128// The caller must have set pkg.Path() to the import path. 129// 130// The operation fails if there were any type-checking or import errors. 131// 132// See ../example_test.go for an example. 133// 134func BuildPackage(tc *types.Config, fset *token.FileSet, pkg *types.Package, files []*ast.File, mode ssa.BuilderMode) (*ssa.Package, *types.Info, error) { 135 if fset == nil { 136 panic("no token.FileSet") 137 } 138 if pkg.Path() == "" { 139 panic("package has no import path") 140 } 141 142 info := &types.Info{ 143 Types: make(map[ast.Expr]types.TypeAndValue), 144 Defs: make(map[*ast.Ident]types.Object), 145 Uses: make(map[*ast.Ident]types.Object), 146 Implicits: make(map[ast.Node]types.Object), 147 Scopes: make(map[ast.Node]*types.Scope), 148 Selections: make(map[*ast.SelectorExpr]*types.Selection), 149 } 150 if err := types.NewChecker(tc, fset, pkg, info).Files(files); err != nil { 151 return nil, nil, err 152 } 153 154 prog := ssa.NewProgram(fset, mode) 155 156 // Create SSA packages for all imports. 157 // Order is not significant. 158 created := make(map[*types.Package]bool) 159 var createAll func(pkgs []*types.Package) 160 createAll = func(pkgs []*types.Package) { 161 for _, p := range pkgs { 162 if !created[p] { 163 created[p] = true 164 prog.CreatePackage(p, nil, nil, true) 165 createAll(p.Imports()) 166 } 167 } 168 } 169 createAll(pkg.Imports()) 170 171 // Create and build the primary package. 172 ssapkg := prog.CreatePackage(pkg, files, info, false) 173 ssapkg.Build() 174 return ssapkg, info, nil 175} 176