| 1 | // Copyright 2013 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 // import "golang.org/x/tools/go/ssa/ssautil" |
| 6 | |
| 7 | import "golang.org/x/tools/go/ssa" |
| 8 | |
| 9 | // This file defines utilities for visiting the SSA representation of |
| 10 | // a Program. |
| 11 | // |
| 12 | // TODO(adonovan): test coverage. |
| 13 | |
| 14 | // AllFunctions finds and returns the set of functions potentially |
| 15 | // needed by program prog, as determined by a simple linker-style |
| 16 | // reachability algorithm starting from the members and method-sets of |
| 17 | // each package. The result may include anonymous functions and |
| 18 | // synthetic wrappers. |
| 19 | // |
| 20 | // Precondition: all packages are built. |
| 21 | func AllFunctions(prog *ssa.Program) map[*ssa.Function]bool { |
| 22 | visit := visitor{ |
| 23 | prog: prog, |
| 24 | seen: make(map[*ssa.Function]bool), |
| 25 | } |
| 26 | visit.program() |
| 27 | return visit.seen |
| 28 | } |
| 29 | |
| 30 | type visitor struct { |
| 31 | prog *ssa.Program |
| 32 | seen map[*ssa.Function]bool |
| 33 | } |
| 34 | |
| 35 | func (visit *visitor) program() { |
| 36 | for _, pkg := range visit.prog.AllPackages() { |
| 37 | for _, mem := range pkg.Members { |
| 38 | if fn, ok := mem.(*ssa.Function); ok { |
| 39 | visit.function(fn) |
| 40 | } |
| 41 | } |
| 42 | } |
| 43 | for _, T := range visit.prog.RuntimeTypes() { |
| 44 | mset := visit.prog.MethodSets.MethodSet(T) |
| 45 | for i, n := 0, mset.Len(); i < n; i++ { |
| 46 | visit.function(visit.prog.MethodValue(mset.At(i))) |
| 47 | } |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | func (visit *visitor) function(fn *ssa.Function) { |
| 52 | if !visit.seen[fn] { |
| 53 | visit.seen[fn] = true |
| 54 | var buf [10]*ssa.Value // avoid alloc in common case |
| 55 | for _, b := range fn.Blocks { |
| 56 | for _, instr := range b.Instrs { |
| 57 | for _, op := range instr.Operands(buf[:0]) { |
| 58 | if fn, ok := (*op).(*ssa.Function); ok { |
| 59 | visit.function(fn) |
| 60 | } |
| 61 | } |
| 62 | } |
| 63 | } |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | // MainPackages returns the subset of the specified packages |
| 68 | // named "main" that define a main function. |
| 69 | // The result may include synthetic "testmain" packages. |
| 70 | func MainPackages(pkgs []*ssa.Package) []*ssa.Package { |
| 71 | var mains []*ssa.Package |
| 72 | for _, pkg := range pkgs { |
| 73 | if pkg.Pkg.Name() == "main" && pkg.Func("main") != nil { |
| 74 | mains = append(mains, pkg) |
| 75 | } |
| 76 | } |
| 77 | return mains |
| 78 | } |
| 79 |
Members