| 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 | |
| 5 | package ssautil |
| 6 | |
| 7 | // This file defines utility functions for constructing programs in SSA form. |
| 8 | |
| 9 | import ( |
| 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 | "golang.org/x/tools/internal/typeparams" |
| 18 | ) |
| 19 | |
| 20 | // Packages creates an SSA program for a set of packages. |
| 21 | // |
| 22 | // The packages must have been loaded from source syntax using the |
| 23 | // golang.org/x/tools/go/packages.Load function in LoadSyntax or |
| 24 | // LoadAllSyntax mode. |
| 25 | // |
| 26 | // Packages creates an SSA package for each well-typed package in the |
| 27 | // initial list, plus all their dependencies. The resulting list of |
| 28 | // packages corresponds to the list of initial packages, and may contain |
| 29 | // a nil if SSA code could not be constructed for the corresponding initial |
| 30 | // package due to type errors. |
| 31 | // |
| 32 | // Code for bodies of functions is not built until Build is called on |
| 33 | // the resulting Program. SSA code is constructed only for the initial |
| 34 | // packages with well-typed syntax trees. |
| 35 | // |
| 36 | // The mode parameter controls diagnostics and checking during SSA construction. |
| 37 | func 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 | func AllPackages(initial []*packages.Package, mode ssa.BuilderMode) (*ssa.Program, []*ssa.Package) { |
| 59 | return doPackages(initial, mode, true) |
| 60 | } |
| 61 | |
| 62 | func doPackages(initial []*packages.Package, mode ssa.BuilderMode, deps bool) (*ssa.Program, []*ssa.Package) { |
| 63 | |
| 64 | var fset *token.FileSet |
| 65 | if len(initial) > 0 { |
| 66 | fset = initial[0].Fset |
| 67 | } |
| 68 | |
| 69 | prog := ssa.NewProgram(fset, mode) |
| 70 | |
| 71 | isInitial := make(map[*packages.Package]bool, len(initial)) |
| 72 | for _, p := range initial { |
| 73 | isInitial[p] = true |
| 74 | } |
| 75 | |
| 76 | ssamap := make(map[*packages.Package]*ssa.Package) |
| 77 | packages.Visit(initial, nil, func(p *packages.Package) { |
| 78 | if p.Types != nil && !p.IllTyped { |
| 79 | var files []*ast.File |
| 80 | var info *types.Info |
| 81 | if deps || isInitial[p] { |
| 82 | files = p.Syntax |
| 83 | info = p.TypesInfo |
| 84 | } |
| 85 | ssamap[p] = prog.CreatePackage(p.Types, files, info, true) |
| 86 | } |
| 87 | }) |
| 88 | |
| 89 | var ssapkgs []*ssa.Package |
| 90 | for _, p := range initial { |
| 91 | ssapkgs = append(ssapkgs, ssamap[p]) // may be nil |
| 92 | } |
| 93 | return prog, ssapkgs |
| 94 | } |
| 95 | |
| 96 | // CreateProgram returns a new program in SSA form, given a program |
| 97 | // loaded from source. An SSA package is created for each transitively |
| 98 | // error-free package of lprog. |
| 99 | // |
| 100 | // Code for bodies of functions is not built until Build is called |
| 101 | // on the result. |
| 102 | // |
| 103 | // The mode parameter controls diagnostics and checking during SSA construction. |
| 104 | // |
| 105 | // Deprecated: Use golang.org/x/tools/go/packages and the Packages |
| 106 | // function instead; see ssa.Example_loadPackages. |
| 107 | func 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 | func BuildPackage(tc *types.Config, fset *token.FileSet, pkg *types.Package, files []*ast.File, mode ssa.BuilderMode) (*ssa.Package, *types.Info, error) { |
| 134 | if fset == nil { |
| 135 | panic("no token.FileSet") |
| 136 | } |
| 137 | if pkg.Path() == "" { |
| 138 | panic("package has no import path") |
| 139 | } |
| 140 | |
| 141 | info := &types.Info{ |
| 142 | Types: make(map[ast.Expr]types.TypeAndValue), |
| 143 | Defs: make(map[*ast.Ident]types.Object), |
| 144 | Uses: make(map[*ast.Ident]types.Object), |
| 145 | Implicits: make(map[ast.Node]types.Object), |
| 146 | Scopes: make(map[ast.Node]*types.Scope), |
| 147 | Selections: make(map[*ast.SelectorExpr]*types.Selection), |
| 148 | } |
| 149 | typeparams.InitInstanceInfo(info) |
| 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 |
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