|
| 1 | +package msgs |
| 2 | + |
| 3 | +import ( |
| 4 | + "go/ast" |
| 5 | + "go/parser" |
| 6 | + "go/token" |
| 7 | + "path/filepath" |
| 8 | + "strings" |
| 9 | + |
| 10 | + "github.com/tendermint/starport/starport/pkg/gomodule" |
| 11 | + "github.com/tendermint/starport/starport/pkg/protoanalysis" |
| 12 | +) |
| 13 | + |
| 14 | +// requirements holds a list of sdk.Msg's method names. |
| 15 | +type requirements map[string]bool |
| 16 | + |
| 17 | +func newRequirements() requirements { |
| 18 | + return requirements{ |
| 19 | + "Reset": false, |
| 20 | + "String": false, |
| 21 | + "ProtoMessage": false, |
| 22 | + "Route": false, |
| 23 | + "Type": false, |
| 24 | + "GetSigners": false, |
| 25 | + "GetSignBytes": false, |
| 26 | + "ValidateBasic": false, |
| 27 | + } |
| 28 | +} |
| 29 | + |
| 30 | +// Msgs is a module import path-sdk msgs pair. |
| 31 | +type Msgs map[string][]string |
| 32 | + |
| 33 | +// Discover discovers and returns pairs of module import path and their types that implements sdk.Msg. |
| 34 | +// sourcePath is the root path of an sdk blockchain. |
| 35 | +// |
| 36 | +// discovery algorithm make use of proto definitions to discover modules inside the blockchain. |
| 37 | +// |
| 38 | +// checking whether a type implements sdk.Msg is done by running a simple algorithm of comparing method names |
| 39 | +// of each type in a package with sdk.Msg's, which satisfies our needs for the time being. |
| 40 | +// for a more opinionated check, go/types.Implements() might be utilized as needed. |
| 41 | +func Discover(sourcePath string) (Msgs, error) { |
| 42 | + // find out base Go import path of the blockchain. |
| 43 | + gm, err := gomodule.ParseAt(sourcePath) |
| 44 | + if err != nil { |
| 45 | + return nil, err |
| 46 | + } |
| 47 | + bpath := gm.Module.Mod.Path |
| 48 | + |
| 49 | + // find proto packages that belongs to modules under x/. |
| 50 | + xprotopkgs, err := findModuleProtoPkgs(sourcePath, bpath) |
| 51 | + if err != nil { |
| 52 | + return nil, err |
| 53 | + } |
| 54 | + |
| 55 | + msgs := make(Msgs) |
| 56 | + |
| 57 | + for _, xproto := range xprotopkgs { |
| 58 | + rxpath := strings.TrimPrefix(xproto.GoImportName, bpath) |
| 59 | + xpath := filepath.Join(sourcePath, rxpath) |
| 60 | + |
| 61 | + xmsgs, err := DiscoverModule(xpath) |
| 62 | + if err != nil { |
| 63 | + return nil, err |
| 64 | + } |
| 65 | + |
| 66 | + msgs[xproto.GoImportName] = xmsgs |
| 67 | + } |
| 68 | + |
| 69 | + return msgs, nil |
| 70 | +} |
| 71 | + |
| 72 | +// DiscoverModule discovers sdk messages defined in a module that resides under modulePath. |
| 73 | +func DiscoverModule(modulePath string) (msgs []string, err error) { |
| 74 | + // parse go packages/files under modulePath. |
| 75 | + fset := token.NewFileSet() |
| 76 | + |
| 77 | + pkgs, err := parser.ParseDir(fset, modulePath, nil, 0) |
| 78 | + if err != nil { |
| 79 | + return nil, err |
| 80 | + } |
| 81 | + |
| 82 | + // collect all structs under modulePath to find out the ones that satisfy requirements. |
| 83 | + structs := make(map[string]requirements) |
| 84 | + |
| 85 | + for _, pkg := range pkgs { |
| 86 | + for _, f := range pkg.Files { |
| 87 | + ast.Inspect(f, func(n ast.Node) bool { |
| 88 | + // look for struct methods. |
| 89 | + fdecl, ok := n.(*ast.FuncDecl) |
| 90 | + if !ok { |
| 91 | + return true |
| 92 | + } |
| 93 | + |
| 94 | + // not a method. |
| 95 | + if fdecl.Recv == nil { |
| 96 | + return true |
| 97 | + } |
| 98 | + |
| 99 | + // fname is the name of method. |
| 100 | + fname := fdecl.Name.Name |
| 101 | + |
| 102 | + // find the struct name that method belongs to. |
| 103 | + sexp, ok := fdecl.Recv.List[0].Type.(*ast.StarExpr) |
| 104 | + if !ok { |
| 105 | + return true |
| 106 | + } |
| 107 | + |
| 108 | + sname := sexp.X.(*ast.Ident).Name |
| 109 | + |
| 110 | + // mark the requirement that this struct satisfies. |
| 111 | + if _, ok := structs[sname]; !ok { |
| 112 | + structs[sname] = newRequirements() |
| 113 | + } |
| 114 | + |
| 115 | + structs[sname][fname] = true |
| 116 | + |
| 117 | + return true |
| 118 | + }) |
| 119 | + } |
| 120 | + } |
| 121 | + |
| 122 | + // checkRequirements checks if all requirements are satisfied. |
| 123 | + checkRequirements := func(r requirements) bool { |
| 124 | + for _, name := range r { |
| 125 | + if name == false { |
| 126 | + return false |
| 127 | + } |
| 128 | + } |
| 129 | + return true |
| 130 | + } |
| 131 | + |
| 132 | + for name, reqs := range structs { |
| 133 | + if checkRequirements(reqs) { |
| 134 | + msgs = append(msgs, name) |
| 135 | + } |
| 136 | + } |
| 137 | + |
| 138 | + return msgs, nil |
| 139 | +} |
| 140 | + |
| 141 | +func findModuleProtoPkgs(sourcePath, bpath string) ([]protoanalysis.Package, error) { |
| 142 | + // find out all proto packages inside blockchain. |
| 143 | + allprotopkgs, err := protoanalysis.DiscoverPackages(sourcePath) |
| 144 | + if err != nil { |
| 145 | + return nil, err |
| 146 | + } |
| 147 | + |
| 148 | + // filter out proto packages that does not reprents x/ modules of blockchain. |
| 149 | + var xprotopkgs []protoanalysis.Package |
| 150 | + for _, pkg := range allprotopkgs { |
| 151 | + if !strings.HasPrefix(pkg.GoImportName, bpath) { |
| 152 | + continue |
| 153 | + } |
| 154 | + |
| 155 | + xprotopkgs = append(xprotopkgs, pkg) |
| 156 | + } |
| 157 | + |
| 158 | + return xprotopkgs, nil |
| 159 | +} |
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