| // Copyright 2015 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 ssautil |
| |
| // This file defines utility functions for constructing programs in SSA form. |
| |
| import ( |
| "go/ast" |
| "go/token" |
| "go/types" |
| |
| "golang.org/x/tools/go/loader" |
| "golang.org/x/tools/go/ssa" |
| ) |
| |
| // CreateProgram returns a new program in SSA form, given a program |
| // loaded from source. An SSA package is created for each transitively |
| // error-free package of lprog. |
| // |
| // Code for bodies of functions is not built until Build is called |
| // on the result. |
| // |
| // mode controls diagnostics and checking during SSA construction. |
| // |
| func CreateProgram(lprog *loader.Program, mode ssa.BuilderMode) *ssa.Program { |
| prog := ssa.NewProgram(lprog.Fset, mode) |
| |
| for _, info := range lprog.AllPackages { |
| if info.TransitivelyErrorFree { |
| prog.CreatePackage(info.Pkg, info.Files, &info.Info, info.Importable) |
| } |
| } |
| |
| return prog |
| } |
| |
| // BuildPackage builds an SSA program with IR for a single package. |
| // |
| // It populates pkg by type-checking the specified file ASTs. All |
| // dependencies are loaded using the importer specified by tc, which |
| // typically loads compiler export data; SSA code cannot be built for |
| // those packages. BuildPackage then constructs an ssa.Program with all |
| // dependency packages created, and builds and returns the SSA package |
| // corresponding to pkg. |
| // |
| // The caller must have set pkg.Path() to the import path. |
| // |
| // The operation fails if there were any type-checking or import errors. |
| // |
| // See ../ssa/example_test.go for an example. |
| // |
| func BuildPackage(tc *types.Config, fset *token.FileSet, pkg *types.Package, files []*ast.File, mode ssa.BuilderMode) (*ssa.Package, *types.Info, error) { |
| if fset == nil { |
| panic("no token.FileSet") |
| } |
| if pkg.Path() == "" { |
| panic("package has no import path") |
| } |
| |
| info := &types.Info{ |
| Types: make(map[ast.Expr]types.TypeAndValue), |
| Defs: make(map[*ast.Ident]types.Object), |
| Uses: make(map[*ast.Ident]types.Object), |
| Implicits: make(map[ast.Node]types.Object), |
| Scopes: make(map[ast.Node]*types.Scope), |
| Selections: make(map[*ast.SelectorExpr]*types.Selection), |
| } |
| if err := types.NewChecker(tc, fset, pkg, info).Files(files); err != nil { |
| return nil, nil, err |
| } |
| |
| prog := ssa.NewProgram(fset, mode) |
| |
| // Create SSA 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 |
| prog.CreatePackage(p, nil, nil, true) |
| createAll(p.Imports()) |
| } |
| } |
| } |
| createAll(pkg.Imports()) |
| |
| // Create and build the primary package. |
| ssapkg := prog.CreatePackage(pkg, files, info, false) |
| ssapkg.Build() |
| return ssapkg, info, nil |
| } |