| 1 | // Copyright 2021 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 generator |
| 6 | |
| 7 | import ( |
| 8 | "bytes" |
| 9 | "fmt" |
| 10 | "os" |
| 11 | "sort" |
| 12 | ) |
| 13 | |
| 14 | // parm is an interface describing an abstract parameter var or return |
| 15 | // var; there will be concrete types of various sorts that implement |
| 16 | // this interface. |
| 17 | type parm interface { |
| 18 | |
| 19 | // Declare emits text containing a declaration of this param |
| 20 | // or return var into the specified buffer. Prefix is a tag to |
| 21 | // prepend before the declaration (for example a variable |
| 22 | // name) followed by a space; suffix is an arbitrary string to |
| 23 | // tack onto the end of the param's type text. Here 'caller' |
| 24 | // is set to true if we're emitting the caller part of a test |
| 25 | // pair as opposed to the checker. |
| 26 | Declare(b *bytes.Buffer, prefix string, suffix string, caller bool) |
| 27 | |
| 28 | // GenElemRef returns a pair [X,Y] corresponding to a |
| 29 | // component piece of some composite parm, where X is a string |
| 30 | // forming the reference (ex: ".field" if we're picking out a |
| 31 | // struct field) and Y is a parm object corresponding to the |
| 32 | // type of the element. |
| 33 | GenElemRef(elidx int, path string) (string, parm) |
| 34 | |
| 35 | // GenValue constructs a new concrete random value appropriate |
| 36 | // for the type in question and returns it, along with a |
| 37 | // sequence number indicating how many random decisions we had |
| 38 | // to make. Here "s" is the current generator state, "f" is |
| 39 | // the current function we're emitting, value is a sequence |
| 40 | // number indicating how many random decisions have been made |
| 41 | // up until this point, and 'caller' is set to true if we're |
| 42 | // emitting the caller part of a test pair as opposed to the |
| 43 | // checker. Return value is a pair [V,I] where V is the text |
| 44 | // if the value, and I is a new sequence number reflecting any |
| 45 | // additional random choices we had to make. For example, if |
| 46 | // the parm is something like "type Foo struct { f1 int32; f2 |
| 47 | // float64 }" then we might expect GenValue to emit something |
| 48 | // like "Foo{int32(-9), float64(123.123)}". |
| 49 | GenValue(s *genstate, f *funcdef, value int, caller bool) (string, int) |
| 50 | |
| 51 | // IsControl returns true if this specific param has been marked |
| 52 | // as the single param that controls recursion for a recursive |
| 53 | // checker function. The test code doesn't check this param for a specific |
| 54 | // value, but instead returns early if it has value 0 or decrements it |
| 55 | // on a recursive call. |
| 56 | IsControl() bool |
| 57 | |
| 58 | // NumElements returns the total number of discrete elements contained |
| 59 | // in this parm. For non-composite types, this will always be 1. |
| 60 | NumElements() int |
| 61 | |
| 62 | // String returns a descriptive string for this parm. |
| 63 | String() string |
| 64 | |
| 65 | // TypeName returns the non-qualified type name for this parm. |
| 66 | TypeName() string |
| 67 | |
| 68 | // QualName returns a package-qualified type name for this parm. |
| 69 | QualName() string |
| 70 | |
| 71 | // HasPointer returns true if this parm is of pointer type, or |
| 72 | // if it is a composite that has a pointer element somewhere inside. |
| 73 | // Strings and slices return true for this hook. |
| 74 | HasPointer() bool |
| 75 | |
| 76 | // IsBlank() returns true if the name of this parm is "_" (that is, |
| 77 | // if we randomly chose to make it a blank). SetBlank() is used |
| 78 | // to set the 'blank' property for this parm. |
| 79 | IsBlank() bool |
| 80 | SetBlank(v bool) |
| 81 | |
| 82 | // AddrTaken() return a token indicating whether this parm should |
| 83 | // be address taken or not, the nature of the address-taken-ness (see |
| 84 | // below at the def of addrTakenHow). SetAddrTaken is used to set |
| 85 | // the address taken property of the parm. |
| 86 | AddrTaken() addrTakenHow |
| 87 | SetAddrTaken(val addrTakenHow) |
| 88 | |
| 89 | // IsGenVal() returns true if the values of this type should |
| 90 | // be obtained by calling a helper func, as opposed to |
| 91 | // emitting code inline (as one would for things like numeric |
| 92 | // types). SetIsGenVal is used to set the gen-val property of |
| 93 | // the parm. |
| 94 | IsGenVal() bool |
| 95 | SetIsGenVal(val bool) |
| 96 | |
| 97 | // SkipCompare() returns true if we've randomly decided that |
| 98 | // we don't want to compare the value for this param or |
| 99 | // return. SetSkipCompare is used to set the skip-compare |
| 100 | // property of the parm. |
| 101 | SkipCompare() skipCompare |
| 102 | SetSkipCompare(val skipCompare) |
| 103 | } |
| 104 | |
| 105 | type addrTakenHow uint8 |
| 106 | |
| 107 | const ( |
| 108 | // Param not address taken. |
| 109 | notAddrTaken addrTakenHow = 0 |
| 110 | |
| 111 | // Param address is taken and used for simple reads/writes. |
| 112 | addrTakenSimple addrTakenHow = 1 |
| 113 | |
| 114 | // Param address is taken and passed to a well-behaved function. |
| 115 | addrTakenPassed addrTakenHow = 2 |
| 116 | |
| 117 | // Param address is taken and stored to a global var. |
| 118 | addrTakenHeap addrTakenHow = 3 |
| 119 | ) |
| 120 | |
| 121 | func (a *addrTakenHow) AddrTaken() addrTakenHow { |
| 122 | return *a |
| 123 | } |
| 124 | |
| 125 | func (a *addrTakenHow) SetAddrTaken(val addrTakenHow) { |
| 126 | *a = val |
| 127 | } |
| 128 | |
| 129 | type isBlank bool |
| 130 | |
| 131 | func (b *isBlank) IsBlank() bool { |
| 132 | return bool(*b) |
| 133 | } |
| 134 | |
| 135 | func (b *isBlank) SetBlank(val bool) { |
| 136 | *b = isBlank(val) |
| 137 | } |
| 138 | |
| 139 | type isGenValFunc bool |
| 140 | |
| 141 | func (g *isGenValFunc) IsGenVal() bool { |
| 142 | return bool(*g) |
| 143 | } |
| 144 | |
| 145 | func (g *isGenValFunc) SetIsGenVal(val bool) { |
| 146 | *g = isGenValFunc(val) |
| 147 | } |
| 148 | |
| 149 | type skipCompare int |
| 150 | |
| 151 | const ( |
| 152 | // Param not address taken. |
| 153 | SkipAll = -1 |
| 154 | SkipNone = 0 |
| 155 | SkipPayload = 1 |
| 156 | ) |
| 157 | |
| 158 | func (s *skipCompare) SkipCompare() skipCompare { |
| 159 | return skipCompare(*s) |
| 160 | } |
| 161 | |
| 162 | func (s *skipCompare) SetSkipCompare(val skipCompare) { |
| 163 | *s = skipCompare(val) |
| 164 | } |
| 165 | |
| 166 | // containedParms takes an arbitrary param 'p' and returns a slice |
| 167 | // with 'p' itself plus any component parms contained within 'p'. |
| 168 | func containedParms(p parm) []parm { |
| 169 | visited := make(map[string]parm) |
| 170 | worklist := []parm{p} |
| 171 | |
| 172 | addToWork := func(p parm) { |
| 173 | if p == nil { |
| 174 | panic("not expected") |
| 175 | } |
| 176 | if _, ok := visited[p.TypeName()]; !ok { |
| 177 | worklist = append(worklist, p) |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | for len(worklist) != 0 { |
| 182 | cp := worklist[0] |
| 183 | worklist = worklist[1:] |
| 184 | if _, ok := visited[cp.TypeName()]; ok { |
| 185 | continue |
| 186 | } |
| 187 | visited[cp.TypeName()] = cp |
| 188 | switch x := cp.(type) { |
| 189 | case *mapparm: |
| 190 | addToWork(x.keytype) |
| 191 | addToWork(x.valtype) |
| 192 | case *structparm: |
| 193 | for _, fld := range x.fields { |
| 194 | addToWork(fld) |
| 195 | } |
| 196 | case *arrayparm: |
| 197 | addToWork(x.eltype) |
| 198 | case *pointerparm: |
| 199 | addToWork(x.totype) |
| 200 | case *typedefparm: |
| 201 | addToWork(x.target) |
| 202 | } |
| 203 | } |
| 204 | rv := []parm{} |
| 205 | for _, v := range visited { |
| 206 | rv = append(rv, v) |
| 207 | } |
| 208 | sort.Slice(rv, func(i, j int) bool { |
| 209 | if rv[i].TypeName() == rv[j].TypeName() { |
| 210 | fmt.Fprintf(os.Stderr, "%d %d %+v %+v %s %s\n", i, j, rv[i], rv[i].String(), rv[j], rv[j].String()) |
| 211 | panic("unexpected") |
| 212 | } |
| 213 | return rv[i].TypeName() < rv[j].TypeName() |
| 214 | }) |
| 215 | return rv |
| 216 | } |
| 217 |
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