diff options
-rw-r--r-- | src/cmd/internal/gc/esc.go | 575 | ||||
-rw-r--r-- | src/cmd/internal/gc/gen.go | 15 | ||||
-rw-r--r-- | src/cmd/internal/gc/go.go | 13 | ||||
-rw-r--r-- | src/cmd/internal/gc/syntax.go | 22 | ||||
-rw-r--r-- | src/cmd/internal/gc/walk.go | 2 | ||||
-rw-r--r-- | src/runtime/proc1.go | 4 | ||||
-rw-r--r-- | src/runtime/string1.go | 6 | ||||
-rw-r--r-- | test/escape2.go | 73 | ||||
-rw-r--r-- | test/escape2n.go | 73 | ||||
-rw-r--r-- | test/escape_array.go | 72 | ||||
-rw-r--r-- | test/escape_calls.go | 44 | ||||
-rw-r--r-- | test/escape_closure.go | 4 | ||||
-rw-r--r-- | test/escape_field.go | 39 | ||||
-rw-r--r-- | test/escape_indir.go | 13 | ||||
-rw-r--r-- | test/escape_level.go | 26 | ||||
-rw-r--r-- | test/escape_param.go | 87 | ||||
-rw-r--r-- | test/escape_struct_param1.go | 298 | ||||
-rw-r--r-- | test/escape_struct_param2.go | 298 | ||||
-rw-r--r-- | test/escape_struct_return.go | 74 | ||||
-rw-r--r-- | test/fixedbugs/issue10353.go | 2 |
20 files changed, 1443 insertions, 297 deletions
diff --git a/src/cmd/internal/gc/esc.go b/src/cmd/internal/gc/esc.go index 4a44de7d78..044bb3d31d 100644 --- a/src/cmd/internal/gc/esc.go +++ b/src/cmd/internal/gc/esc.go @@ -205,64 +205,187 @@ const ( EscFuncTagged ) -type EscState struct { - // Fake node that all - // - return values and output variables - // - parameters on imported functions not marked 'safe' - // - assignments to global variables - // flow to. - theSink Node +// There appear to be some loops in the escape graph, causing +// arbitrary recursion into deeper and deeper levels. +// Cut this off safely by making minLevel sticky: once you +// get that deep, you cannot go down any further but you also +// cannot go up any further. This is a conservative fix. +// Making minLevel smaller (more negative) would handle more +// complex chains of indirections followed by address-of operations, +// at the cost of repeating the traversal once for each additional +// allowed level when a loop is encountered. Using -2 suffices to +// pass all the tests we have written so far, which we assume matches +// the level of complexity we want the escape analysis code to handle. +const ( + MinLevel = -2 +) - // If an analyzed function is recorded to return - // pieces obtained via indirection from a parameter, - // and later there is a call f(x) to that function, - // we create a link funcParam <- x to record that fact. - // The funcParam node is handled specially in escflood. - funcParam Node +// A Level encodes the reference state and context applied to +// (stack, heap) allocated memory. +// +// value is the overall sum of *(1) and &(-1) operations encountered +// along a path from a destination (sink, return value) to a source +// (allocation, parameter). +// +// suffixValue is the maximum-copy-started-suffix-level applied to a sink. +// For example: +// sink = x.left.left --> level=2, x is dereferenced twice and does not escape to sink. +// sink = &Node{x} --> level=-1, x is accessible from sink via one "address of" +// sink = &Node{&Node{x}} --> level=-2, x is accessible from sink via two "address of" +// sink = &Node{&Node{x.left}} --> level=-1, but x is NOT accessible from sink because it was indirected and then copied. +// (The copy operations are sometimes implicit in the source code; in this case, +// value of x.left was copied into a field of a newly allocated Node) +// +// There's one of these for each Node, and the integer values +// rarely exceed even what can be stored in 4 bits, never mind 8. +type Level struct { + value, suffixValue int8 +} - dsts *NodeList // all dst nodes - loopdepth int // for detecting nested loop scopes - pdepth int // for debug printing in recursions. - dstcount int // diagnostic - edgecount int // diagnostic - noesc *NodeList // list of possible non-escaping nodes, for printing - recursive bool // recursive function or group of mutually recursive functions. +func (l Level) int() int { + return int(l.value) } -var tags [16]*string +func levelFrom(i int) Level { + if i <= MinLevel { + return Level{value: MinLevel} + } + return Level{value: int8(i)} +} -// mktag returns the string representation for an escape analysis tag. -func mktag(mask int) *string { - switch mask & EscMask { - case EscNone, EscReturn: - break +func satInc8(x int8) int8 { + if x == 127 { + return 127 + } + return x + 1 +} - default: - Fatal("escape mktag") +func satAdd8(x, y int8) int8 { + z := x + y + if x^y < 0 || x^z >= 0 { + return z + } + if x < 0 { + return -128 } + return 127 +} - mask >>= EscBits +func min8(a, b int8) int8 { + if a < b { + return a + } + return b +} - if mask < len(tags) && tags[mask] != nil { - return tags[mask] +func max8(a, b int8) int8 { + if a > b { + return a } + return b +} - s := fmt.Sprintf("esc:0x%x", mask) - if mask < len(tags) { - tags[mask] = &s +// inc returns the level l + 1, representing the effect of an indirect (*) operation. +func (l Level) inc() Level { + if l.value <= MinLevel { + return Level{value: MinLevel} } - return &s + return Level{value: satInc8(l.value), suffixValue: satInc8(l.suffixValue)} } -func parsetag(note *string) int { - if note == nil || !strings.HasPrefix(*note, "esc:") { - return EscUnknown +// dec returns the level l - 1, representing the effect of an address-of (&) operation. +func (l Level) dec() Level { + if l.value <= MinLevel { + return Level{value: MinLevel} } - em := atoi((*note)[4:]) - if em == 0 { - return EscNone + return Level{value: l.value - 1, suffixValue: l.suffixValue - 1} +} + +// copy returns the level for a copy of a value with level l. +func (l Level) copy() Level { + return Level{value: l.value, suffixValue: max8(l.suffixValue, 0)} +} + +func (l1 Level) min(l2 Level) Level { + return Level{ + value: min8(l1.value, l2.value), + suffixValue: min8(l1.suffixValue, l2.suffixValue)} +} + +// guaranteedDereference returns the number of dereferences +// applied to a pointer before addresses are taken/generated. +// This is the maximum level computed from path suffixes starting +// with copies where paths flow from destination to source. +func (l Level) guaranteedDereference() int { + return int(l.suffixValue) +} + +// Escape constants are numbered in order of increasing "escapiness" +// to help make inferences be monotonic. With the exception of +// EscNever which is sticky, eX < eY means that eY is more exposed +// than eX, and hence replaces it in a conservative analysis. +const ( + EscUnknown = iota + EscNone // Does not escape to heap, result, or parameters. + EscReturn // Is returned or reachable from returned. + EscScope // Allocated in an inner loop scope, assigned to an outer loop scope, + // which allows the construction of non-escaping but arbitrarily large linked + // data structures (i.e., not eligible for allocation in a fixed-size stack frame). + EscHeap // Reachable from the heap + EscNever // By construction will not escape. + EscBits = 3 + EscMask = (1 << EscBits) - 1 + EscContentEscapes = 1 << EscBits // value obtained by indirect of parameter escapes to heap + EscReturnBits = EscBits + 1 + // Node.esc encoding = | escapeReturnEncoding:(width-4) | contentEscapes:1 | escEnum:3 +) + +// escMax returns the maximum of an existing escape value +// (and its additional parameter flow flags) and a new escape type. +func escMax(e, etype uint16) uint16 { + if e&EscMask == EscHeap { + // normalize + if e != EscHeap { + Fatal("Escape information had tag bits combined with 'EscHeap' ") + } + return EscHeap } - return EscReturn | em<<EscBits + if e&EscMask > etype { + return e + } + if etype == EscNone || etype == EscReturn { + return (e &^ EscMask) | etype + } + return etype +} + +// For each input parameter to a function, the escapeReturnEncoding describes +// how the parameter may leak to the function's outputs. This is currently the +// "level" of the leak where level is 0 or larger (negative level means stored into +// something whose address is returned -- but that implies stored into the heap, +// hence EscHeap, which means that the details are not currently relevant. ) +const ( + bitsPerOutputInTag = 3 // For each output, the number of bits for a tag + bitsMaskForTag = uint16(1<<bitsPerOutputInTag) - 1 // The bit mask to extract a single tag. + outputsPerTag = (16 - EscReturnBits) / bitsPerOutputInTag // The number of outputs that can be tagged. + maxEncodedLevel = int(bitsMaskForTag - 1) // The largest level that can be stored in a tag. +) + +type EscState struct { + // Fake node that all + // - return values and output variables + // - parameters on imported functions not marked 'safe' + // - assignments to global variables + // flow to. + theSink Node + + dsts *NodeList // all dst nodes + loopdepth int // for detecting nested loop scopes + pdepth int // for debug printing in recursions. + dstcount int // diagnostic + edgecount int // diagnostic + noesc *NodeList // list of possible non-escaping nodes, for printing + recursive bool // recursive function or group of mutually recursive functions. } func escAnalyze(all *NodeList, recursive bool) { @@ -275,12 +398,6 @@ func escAnalyze(all *NodeList, recursive bool) { e.theSink.Escloopdepth = -1 e.recursive = recursive - e.funcParam.Op = ONAME - e.funcParam.Orig = &e.funcParam - e.funcParam.Class = PAUTO - e.funcParam.Sym = Lookup(".param") - e.funcParam.Escloopdepth = 10000000 - for l := all; l != nil; l = l.Next { if l.N.Op == ODCLFUNC { l.N.Esc = EscFuncPlanned @@ -799,7 +916,10 @@ func escassign(e *EscState, dst *Node, src *Node) { } else { tmp = nil } - fmt.Printf("%v:[%d] %v escassign: %v(%v) = %v(%v)\n", Ctxt.Line(int(lineno)), e.loopdepth, tmp, Nconv(dst, obj.FmtShort), Jconv(dst, obj.FmtShort), Nconv(src, obj.FmtShort), Jconv(src, obj.FmtShort)) + fmt.Printf("%v:[%d] %v escassign: %v(%v)[%v] = %v(%v)[%v]\n", + Ctxt.Line(int(lineno)), e.loopdepth, tmp, + Nconv(dst, obj.FmtShort), Jconv(dst, obj.FmtShort), Oconv(int(dst.Op), 0), + Nconv(src, obj.FmtShort), Jconv(src, obj.FmtShort), Oconv(int(src.Op), 0)) } setlineno(dst) @@ -887,7 +1007,7 @@ func escassign(e *EscState, dst *Node, src *Node) { a.Type = Ptrto(src.Type) escflows(e, dst, a) - // Flowing multiple returns to a single dst happens when + // Flowing multiple returns to a single dst happens when // analyzing "go f(g())": here g() flows to sink (issue 4529). case OCALLMETH, OCALLFUNC, OCALLINTER: for ll := src.Escretval; ll != nil; ll = ll.Next { @@ -953,9 +1073,110 @@ func escassign(e *EscState, dst *Node, src *Node) { lineno = int32(lno) } -func escassignfromtag(e *EscState, note *string, dsts *NodeList, src *Node) int { +// Common case for escapes is 16 bits 000000000xxxEEEE +// where commonest cases for xxx encoding in-to-out pointer +// flow are 000, 001, 010, 011 and EEEE is computed Esc bits. +// Note width of xxx depends on value of constant +// bitsPerOutputInTag -- expect 2 or 3, so in practice the +// tag cache array is 64 or 128 long. Some entries will +// never be populated. +var tags [1 << (bitsPerOutputInTag + EscReturnBits)]string + +// mktag returns the string representation for an escape analysis tag. +func mktag(mask int) *string { + switch mask & EscMask { + case EscNone, EscReturn: + break + + default: + Fatal("escape mktag") + } + + if mask < len(tags) && tags[mask] != "" { + return &tags[mask] + } + + s := fmt.Sprintf("esc:0x%x", mask) + if mask < len(tags) { + tags[mask] = s + } + return &s +} + +// parsetag decodes an escape analysis tag and returns the esc value. +func parsetag(note *string) uint16 { + if note == nil || !strings.HasPrefix(*note, "esc:") { + return EscUnknown + } + em := uint16(atoi((*note)[4:])) + if em == 0 { + return EscNone + } + return em +} + +// describeEscape returns a string describing the escape tag. +// The result is either one of {EscUnknown, EscNone, EscHeap} which all have no further annotation +// or a description of parameter flow, which takes the form of an optional "contentToHeap" +// indicating that the content of this parameter is leaked to the heap, followed by a sequence +// of level encodings separated by spaces, one for each parameter, where _ means no flow, +// = means direct flow, and N asterisks (*) encodes content (obtained by indirection) flow. +// e.g., "contentToHeap _ =" means that a parameter's content (one or more dereferences) +// escapes to the heap, the parameter does not leak to the first output, but does leak directly +// to the second output (and if there are more than two outputs, there is no flow to those.) +func describeEscape(em uint16) string { + var s string + if em&EscMask == EscUnknown { + s = "EscUnknown" + } + if em&EscMask == EscNone { + s = "EscNone" + } + if em&EscMask == EscHeap { + s = "EscHeap" + } + if em&EscMask == EscReturn { + s = "EscReturn" + } + if em&EscMask == EscScope { + s = "EscScope" + } + if em&EscContentEscapes != 0 { + if s != "" { + s += " " + } + s += "contentToHeap" + } + for em >>= EscReturnBits; em != 0; em = em >> bitsPerOutputInTag { + // See encoding description above + if s != "" { + s += " " + } + switch embits := em & bitsMaskForTag; embits { + case 0: + s += "_" + case 1: + s += "=" + default: + for i := uint16(0); i < embits-1; i++ { + s += "*" + } + } + + } + return s +} + +// escassignfromtag models the input-to-output assignment flow of one of a function +// calls arguments, where the flow is encoded in "note". +func escassignfromtag(e *EscState, note *string, dsts *NodeList, src *Node) uint16 { em := parsetag(note) + if Debug['m'] > 2 { + fmt.Printf("%v::assignfromtag:: src=%v, em=%s\n", + Ctxt.Line(int(lineno)), Nconv(src, obj.FmtShort), describeEscape(em)) + } + if em == EscUnknown { escassign(e, &e.theSink, src) return em @@ -966,17 +1187,30 @@ func escassignfromtag(e *EscState, note *string, dsts *NodeList, src *Node) int } // If content inside parameter (reached via indirection) - // escapes back to results, mark as such. + // escapes to heap, mark as such. if em&EscContentEscapes != 0 { - escassign(e, &e.funcParam, src) + escassign(e, &e.theSink, addDereference(src)) } em0 := em - for em >>= EscReturnBits; em != 0 && dsts != nil; em, dsts = em>>1, dsts.Next { - if em&1 != 0 { - escassign(e, dsts.N, src) + for em >>= EscReturnBits; em != 0 && dsts != nil; em, dsts = em>>bitsPerOutputInTag, dsts.Next { + // Prefer the lowest-level path to the reference (for escape purposes). + // Two-bit encoding (for example. 1, 3, and 4 bits are other options) + // 01 = 0-level + // 10 = 1-level, (content escapes), + // 11 = 2-level, (content of content escapes), + embits := em & bitsMaskForTag + if embits > 0 { + n := src + for i := uint16(0); i < embits-1; i++ { + n = addDereference(n) // encode level>0 as indirections + } + escassign(e, dsts.N, n) } } + // If there are too many outputs to fit in the tag, + // that is handled at the encoding end as EscHeap, + // so there is no need to check here. if em != 0 && dsts == nil { Fatal("corrupt esc tag %q or messed up escretval list\n", note) @@ -984,6 +1218,58 @@ func escassignfromtag(e *EscState, note *string, dsts *NodeList, src *Node) int return em0 } +// addDereference constructs a suitable OIND note applied to src. +// Because this is for purposes of escape accounting, not execution, +// some semantically dubious node combinations are (currently) possible. +func addDereference(n *Node) *Node { + ind := Nod(OIND, n, nil) + ind.Escloopdepth = n.Escloopdepth + ind.Lineno = n.Lineno + t := n.Type + if Istype(t, Tptr) { + // This should model our own sloppy use of OIND to encode + // decreasing levels of indirection; i.e., "indirecting" an array + // might yield the type of an element. To be enhanced... + t = t.Type + } + ind.Type = t + return ind +} + +// escNoteOutputParamFlow encodes maxEncodedLevel/.../1/0-level flow to the vargen'th parameter. +// Levels greater than maxEncodedLevel are replaced with maxEncodedLevel. +// If the encoding cannot describe the modified input level and output number, then EscHeap is returned. +func escNoteOutputParamFlow(e uint16, vargen int32, level Level) uint16 { + // Flow+level is encoded in two bits. + // 00 = not flow, xx = level+1 for 0 <= level <= maxEncodedLevel + // 16 bits for Esc allows 6x2bits or 4x3bits or 3x4bits if additional information would be useful. + if level.int() <= 0 && level.guaranteedDereference() > 0 { + return escMax(e|EscContentEscapes, EscNone) // At least one deref, thus only content. + } + if level.int() < 0 { + return EscHeap + } + if level.int() > maxEncodedLevel { + // Cannot encode larger values than maxEncodedLevel. + level = levelFrom(maxEncodedLevel) + } + encoded := uint16(level.int() + 1) + + shift := uint(bitsPerOutputInTag*(vargen-1) + EscReturnBits) + old := (e >> shift) & bitsMaskForTag + if old == 0 || encoded != 0 && encoded < old { + old = encoded + } + + encodedFlow := old << shift + if (encodedFlow>>shift)&bitsMaskForTag != old { + // Encoding failure defaults to heap. + return EscHeap + } + + return (e &^ (bitsMaskForTag << shift)) | encodedFlow +} + // This is a bit messier than fortunate, pulled out of esc's big // switch for clarity. We either have the paramnodes, which may be // connected to other things through flows or we have the parameter type @@ -1022,7 +1308,12 @@ func esccall(e *EscState, n *Node, up *Node) { } } - if fn != nil && fn.Op == ONAME && fn.Class == PFUNC && fn.Defn != nil && fn.Defn.Nbody != nil && fn.Ntype != nil && fn.Defn.Esc < EscFuncTagged { + if fn != nil && fn.Op == ONAME && fn.Class == PFUNC && + fn.Defn != nil && fn.Defn.Nbody != nil && fn.Ntype != nil && fn.Defn.Esc < EscFuncTagged { + if Debug['m'] > 2 { + fmt.Printf("%v::esccall:: %v in recursive group\n", Ctxt.Line(int(lineno)), Nconv(n, obj.FmtShort)) + } + // function in same mutually recursive group. Incorporate into flow graph. // print("esc local fn: %N\n", fn->ntype); if fn.Defn.Esc == EscFuncUnknown || n.Escretval != nil { @@ -1067,6 +1358,9 @@ func esccall(e *EscState, n *Node, up *Node) { // "..." arguments are untracked for ; ll != nil; ll = ll.Next { + if Debug['m'] > 2 { + fmt.Printf("%v::esccall:: ... <- %v, untracked\n", Ctxt.Line(int(lineno)), Nconv(ll.N, obj.FmtShort)) + } escassign(e, &e.theSink, ll.N) } @@ -1078,6 +1372,10 @@ func esccall(e *EscState, n *Node, up *Node) { Fatal("esc already decorated call %v\n", Nconv(n, obj.FmtSign)) } + if Debug['m'] > 2 { + fmt.Printf("%v::esccall:: %v not recursive\n", Ctxt.Line(int(lineno)), Nconv(n, obj.FmtShort)) + } + // set up out list on this call node with dummy auto ONAMES in the current (calling) function. i := 0 @@ -1085,7 +1383,7 @@ func esccall(e *EscState, n *Node, up *Node) { var buf string for t := getoutargx(fntype).Type; t != nil; t = t.Down { src = Nod(ONAME, nil, nil) - buf = fmt.Sprintf(".dum%d", i) + buf = fmt.Sprintf(".out%d", i) i++ src.Sym = Lookup(buf) src.Type = t.Type @@ -1162,10 +1460,14 @@ func esccall(e *EscState, n *Node, up *Node) { // "..." arguments are untracked for ; ll != nil; ll = ll.Next { escassign(e, &e.theSink, ll.N) + if Debug['m'] > 2 { + fmt.Printf("%v::esccall:: ... <- %v, untracked\n", Ctxt.Line(int(lineno)), Nconv(ll.N, obj.FmtShort)) + } } } -// Store the link src->dst in dst, throwing out some quick wins. +// escflows records the link src->dst in dst, throwing out some quick wins, +// and also ensuring that dst is noted as a flow destination. func escflows(e *EscState, dst *Node, src *Node) { if dst == nil || src == nil || dst == src { return @@ -1220,31 +1522,31 @@ func escflood(e *EscState, dst *Node) { for l := dst.Escflowsrc; l != nil; l = l.Next { walkgen++ - escwalk(e, 0, dst, l.N) + escwalk(e, levelFrom(0), dst, l.N) } } -// There appear to be some loops in the escape graph, causing -// arbitrary recursion into deeper and deeper levels. -// Cut this off safely by making minLevel sticky: once you -// get that deep, you cannot go down any further but you also -// cannot go up any further. This is a conservative fix. -// Making minLevel smaller (more negative) would handle more -// complex chains of indirections followed by address-of operations, -// at the cost of repeating the traversal once for each additional -// allowed level when a loop is encountered. Using -2 suffices to -// pass all the tests we have written so far, which we assume matches -// the level of complexity we want the escape analysis code to handle. -const ( - MinLevel = -2 -) +// funcOutputAndInput reports whether dst and src correspond to output and input parameters of the same function. +func funcOutputAndInput(dst, src *Node) bool { + // Note if dst is marked as escaping, then "returned" is too weak. + return dst.Op == ONAME && dst.Class == PPARAMOUT && + src.Op == ONAME && src.Class == PPARAM && src.Curfn == dst.Curfn +} -func escwalk(e *EscState, level int, dst *Node, src *Node) { - if src.Walkgen == walkgen && src.Esclevel <= int32(level) { - return +func escwalk(e *EscState, level Level, dst *Node, src *Node) { + + if src.Walkgen == walkgen { + // Esclevels are vectors, do not compare as integers, + // and must use "min" of old and new to guarantee + // convergence. + level = level.min(src.Esclevel) + if level == src.Esclevel { + return + } } + src.Walkgen = walkgen - src.Esclevel = int32(level) + src.Esclevel = level if Debug['m'] > 1 { var tmp *Sym @@ -1253,48 +1555,70 @@ func escwalk(e *EscState, level int, dst *Node, src *Node) { } else { tmp = nil } - fmt.Printf("escwalk: level:%d depth:%d %.*s %v(%v) scope:%v[%d]\n", level, e.pdepth, e.pdepth, "\t\t\t\t\t\t\t\t\t\t", Nconv(src, obj.FmtShort), Jconv(src, obj.FmtShort), tmp, src.Escloopdepth) + fmt.Printf("escwalk: level:%d depth:%d %.*s op=%v %v(%v) scope:%v[%d]\n", + level, e.pdepth, e.pdepth, "\t\t\t\t\t\t\t\t\t\t", Oconv(int(src.Op), 0), Nconv(src, obj.FmtShort), Jconv(src, obj.FmtShort), tmp, src.Escloopdepth) } e.pdepth++ // Input parameter flowing to output parameter? var leaks bool - if dst.Op == ONAME && dst.Class == PPARAMOUT && dst.Vargen <= 20 { - if src.Op == ONAME && src.Class == PPARAM && src.Curfn == dst.Curfn && src.Esc != EscScope && src.Esc != EscHeap { - if level == 0 { - if Debug['m'] != 0 { - Warnl(int(src.Lineno), "leaking param: %v to result %v", Nconv(src, obj.FmtShort), dst.Sym) - } - if src.Esc&EscMask != EscReturn { - src.Esc = EscReturn - } - src.Esc |= 1 << uint((dst.Vargen-1)+EscReturnBits) - goto recurse - } else if level > 0 { - if Debug['m'] != 0 { - Warnl(int(src.Lineno), "%v leaking param %v content to result %v", src.Curfn.Nname, Nconv(src, obj.FmtShort), dst.Sym) - } - if src.Esc&EscMask != EscReturn { - src.Esc = EscReturn - } - src.Esc |= EscContentEscapes - goto recurse + if funcOutputAndInput(dst, src) && src.Esc&EscMask != EscScope && src.Esc != EscHeap && dst.Esc != EscHeap { + // This case handles: + // 1. return in + // 2. return &in + // 3. tmp := in; return &tmp + // 4. return *in + if Debug['m'] != 0 { + if Debug['m'] == 1 { + Warnl(int(src.Lineno), "leaking param: %v to result %v level=%v", Nconv(src, obj.FmtShort), dst.Sym, level.int()) + } else { + Warnl(int(src.Lineno), "leaking param: %v to result %v level=%v", Nconv(src, obj.FmtShort), dst.Sym, level) } } + if src.Esc&EscMask != EscReturn { + src.Esc = EscReturn | src.Esc&EscContentEscapes + } + src.Esc = escNoteOutputParamFlow(src.Esc, dst.Vargen, level) + goto recurse } - // The second clause is for values pointed at by an object passed to a call - // that returns something reached via indirect from the object. - // We don't know which result it is or how many indirects, so we treat it as leaking. - leaks = level <= 0 && dst.Escloopdepth < src.Escloopdepth || level < 0 && dst == &e.funcParam && haspointers(src.Type) + // If parameter content escapes to heap, set EscContentEscapes + // Note minor confusion around escape from pointer-to-struct vs escape from struct + if dst.Esc == EscHeap && + src.Op == ONAME && src.Class == PPARAM && src.Esc != EscHeap && + level.int() > 0 { + src.Esc = escMax(EscContentEscapes|src.Esc, EscNone) + if Debug['m'] != 0 { + Warnl(int(src.Lineno), "mark escaped content: %v", Nconv(src, obj.FmtShort)) + } + } + + leaks = level.int() <= 0 && level.guaranteedDereference() <= 0 && dst.Escloopdepth < src.Escloopdepth switch src.Op { case ONAME: if src.Class == PPARAM && (leaks || dst.Escloopdepth < 0) && src.Esc != EscHeap { - src.Esc = EscScope - if Debug['m'] != 0 { - Warnl(int(src.Lineno), "leaking param: %v", Nconv(src, obj.FmtShort)) + if level.guaranteedDereference() > 0 { + src.Esc = escMax(EscContentEscapes|src.Esc, EscNone) + if Debug['m'] != 0 { + if Debug['m'] == 1 { + Warnl(int(src.Lineno), "leaking param content: %v", Nconv(src, obj.FmtShort)) + } else { + Warnl(int(src.Lineno), "leaking param content: %v level=%v dst.eld=%v src.eld=%v dst=%v", + Nconv(src, obj.FmtShort), level, dst.Escloopdepth, src.Escloopdepth, Nconv(dst, obj.FmtShort)) + } + } + } else { + src.Esc = EscScope + if Debug['m'] != 0 { + if Debug['m'] == 1 { + Warnl(int(src.Lineno), "leaking param: %v", Nconv(src, obj.FmtShort)) + } else { + Warnl(int(src.Lineno), "leaking param: %v level=%v dst.eld=%v src.eld=%v dst=%v", + Nconv(src, obj.FmtShort), level, dst.Escloopdepth, src.Escloopdepth, Nconv(dst, obj.FmtShort)) + } + } } } @@ -1316,15 +1640,19 @@ func escwalk(e *EscState, level int, dst *Node, src *Node) { if p.Left.Op == OCLOSURE { p = p.Left // merely to satisfy error messages in tests } - Warnl(int(src.Lineno), "%v escapes to heap", Nconv(p, obj.FmtShort)) + if Debug['m'] > 1 { + Warnl(int(src.Lineno), "%v escapes to heap, level=%v, dst.eld=%v, src.eld=%v", + Nconv(p, obj.FmtShort), level, dst.Escloopdepth, src.Escloopdepth) + } else { + Warnl(int(src.Lineno), "%v escapes to heap", Nconv(p, obj.FmtShort)) + } } } - newlevel := level - if level > MinLevel { - newlevel-- - } - escwalk(e, newlevel, dst, src.Left) + escwalk(e, level.dec(), dst, src.Left) + + case OAPPEND: + escwalk(e, level, dst, src.List.N) case OARRAYLIT: if Isfixedarray(src.Type) { @@ -1332,7 +1660,6 @@ func escwalk(e *EscState, level int, dst *Node, src *Node) { } fallthrough - // fall through case ODDDARG, OMAKECHAN, OMAKEMAP, @@ -1370,17 +1697,27 @@ func escwalk(e *EscState, level int, dst *Node, src *Node) { } fallthrough - // fall through case ODOTPTR, OINDEXMAP, OIND: - newlevel := level + escwalk(e, level.inc(), dst, src.Left) - if level > MinLevel { - newlevel++ + // In this case a link went directly to a call, but should really go + // to the dummy .outN outputs that were created for the call that + // themselves link to the inputs with levels adjusted. + // See e.g. #10466 + // This can only happen with functions returning a single result. + case OCALLMETH, OCALLFUNC, OCALLINTER: + if src.Escretval != nil { + if Debug['m'] > 1 { + fmt.Printf("%v:[%d] dst %v escwalk replace src: %v with %v\n", + Ctxt.Line(int(lineno)), e.loopdepth, + Nconv(dst, obj.FmtShort), Nconv(src, obj.FmtShort), Nconv(src.Escretval.N, obj.FmtShort)) + } + src = src.Escretval.N } - escwalk(e, newlevel, dst, src.Left) } recurse: + level = level.copy() for ll := src.Escflowsrc; ll != nil; ll = ll.Next { escwalk(e, level, dst, ll.N) } @@ -1409,7 +1746,7 @@ func esctag(e *EscState, func_ *Node) { Curfn = func_ for ll := Curfn.Func.Dcl; ll != nil; ll = ll.Next { - if ll.N.Op != ONAME || ll.N.Class != PPARAM { + if ll.N.Op != ONAME { continue } diff --git a/src/cmd/internal/gc/gen.go b/src/cmd/internal/gc/gen.go index 4c03915c08..e6af897033 100644 --- a/src/cmd/internal/gc/gen.go +++ b/src/cmd/internal/gc/gen.go @@ -23,11 +23,10 @@ func Sysfunc(name string) *Node { return n } -/* - * the address of n has been taken and might be used after - * the current function returns. mark any local vars - * as needing to move to the heap. - */ +// addrescapes tags node n as having had its address taken +// by "increasing" the "value" of n.Esc to EscHeap. +// Storage is allocated as necessary to allow the address +// to be taken. func addrescapes(n *Node) { switch n.Op { // probably a type error already. @@ -50,7 +49,7 @@ func addrescapes(n *Node) { case PPARAMREF: addrescapes(n.Defn) - // if func param, need separate temporary + // if func param, need separate temporary // to hold heap pointer. // the function type has already been checked // (we're in the function body) @@ -93,12 +92,12 @@ func addrescapes(n *Node) { case OIND, ODOTPTR: break - // ODOTPTR has already been introduced, + // ODOTPTR has already been introduced, // so these are the non-pointer ODOT and OINDEX. // In &x[0], if x is a slice, then x does not // escape--the pointer inside x does, but that // is always a heap pointer anyway. - case ODOT, OINDEX: + case ODOT, OINDEX, OPAREN, OCONVNOP: if !Isslice(n.Left.Type) { addrescapes(n.Left) } diff --git a/src/cmd/internal/gc/go.go b/src/cmd/internal/gc/go.go index 2d85f58580..71bce0bf2c 100644 --- a/src/cmd/internal/gc/go.go +++ b/src/cmd/internal/gc/go.go @@ -215,19 +215,6 @@ type InitPlan struct { } const ( - EscUnknown = iota - EscHeap - EscScope - EscNone - EscReturn - EscNever - EscBits = 3 - EscMask = (1 << EscBits) - 1 - EscContentEscapes = 1 << EscBits // value obtained by indirect of parameter escapes to some returned result - EscReturnBits = EscBits + 1 -) - -const ( SymExport = 1 << 0 // to be exported SymPackage = 1 << 1 SymExported = 1 << 2 // already written out by export diff --git a/src/cmd/internal/gc/syntax.go b/src/cmd/internal/gc/syntax.go index e9593fdcb9..7c9fb8d2b8 100644 --- a/src/cmd/internal/gc/syntax.go +++ b/src/cmd/internal/gc/syntax.go @@ -44,15 +44,15 @@ type Node struct { Isddd bool // is the argument variadic Readonly bool Implicit bool - Addrtaken bool // address taken, even if not moved to heap - Assigned bool // is the variable ever assigned to - Captured bool // is the variable captured by a closure - Byval bool // is the variable captured by value or by reference - Reslice bool // this is a reslice x = x[0:y] or x = append(x, ...) - Likely int8 // likeliness of if statement - Hasbreak bool // has break statement - Needzero bool // if it contains pointers, needs to be zeroed on function entry - Esc uint8 // EscXXX + Addrtaken bool // address taken, even if not moved to heap + Assigned bool // is the variable ever assigned to + Captured bool // is the variable captured by a closure + Byval bool // is the variable captured by value or by reference + Reslice bool // this is a reslice x = x[0:y] or x = append(x, ...) + Likely int8 // likeliness of if statement + Hasbreak bool // has break statement + Needzero bool // if it contains pointers, needs to be zeroed on function entry + Esc uint16 // EscXXX Funcdepth int32 // most nodes @@ -103,14 +103,14 @@ type Node struct { Escloopdepth int // -1: global, 0: return variables, 1:function top level, increased inside function for every loop or label to mark scopes Sym *Sym // various - Vargen int32 // unique name for OTYPE/ONAME + Vargen int32 // unique name for OTYPE/ONAME within a function. Function outputs are numbered starting at one. Lineno int32 Xoffset int64 Stkdelta int64 // offset added by stack frame compaction phase. Ostk int32 // 6g only Iota int32 Walkgen uint32 - Esclevel int32 + Esclevel Level Opt interface{} // for optimization passes } diff --git a/src/cmd/internal/gc/walk.go b/src/cmd/internal/gc/walk.go index bc886d9eef..37e18edf12 100644 --- a/src/cmd/internal/gc/walk.go +++ b/src/cmd/internal/gc/walk.go @@ -1777,7 +1777,7 @@ func ascompatet(op int, nl *NodeList, nr **Type, fp int, init **NodeList) *NodeL * package all the arguments that match a ... T parameter into a []T. */ func mkdotargslice(lr0 *NodeList, nn *NodeList, l *Type, fp int, init **NodeList, ddd *Node) *NodeList { - esc := uint8(EscUnknown) + esc := uint16(EscUnknown) if ddd != nil { esc = ddd.Esc } diff --git a/src/runtime/proc1.go b/src/runtime/proc1.go index c5c1173a15..8b87f818d3 100644 --- a/src/runtime/proc1.go +++ b/src/runtime/proc1.go @@ -3531,9 +3531,13 @@ func testSchedLocalQueue() { } } +var pSink *p + func testSchedLocalQueueSteal() { p1 := new(p) p2 := new(p) + pSink = p1 // Force to heap, too large to allocate on system stack ("G0 stack") + pSink = p2 // Force to heap, too large to allocate on system stack ("G0 stack") gs := make([]g, len(p1.runq)) for i := 0; i < len(p1.runq); i++ { for j := 0; j < i; j++ { diff --git a/src/runtime/string1.go b/src/runtime/string1.go index feeb341b62..4bfa3d95f9 100644 --- a/src/runtime/string1.go +++ b/src/runtime/string1.go @@ -35,10 +35,8 @@ var maxstring uintptr = 256 // a hint for print //go:nosplit func gostringnocopy(str *byte) string { - var s string - sp := (*stringStruct)(unsafe.Pointer(&s)) - sp.str = unsafe.Pointer(str) - sp.len = findnull(str) + ss := stringStruct{str: unsafe.Pointer(str), len: findnull(str)} + s := *(*string)(unsafe.Pointer(&ss)) for { ms := maxstring if uintptr(len(s)) <= ms || casuintptr(&maxstring, ms, uintptr(len(s))) { diff --git a/test/escape2.go b/test/escape2.go index dbb2292943..cc714711cf 100644 --- a/test/escape2.go +++ b/test/escape2.go @@ -59,7 +59,7 @@ func foo8(xx, yy *int) int { // ERROR "foo8 xx does not escape$" "foo8 yy does n return *xx } -func foo9(xx, yy *int) *int { // ERROR "leaking param: xx to result ~r2$" "leaking param: yy to result ~r2$" +func foo9(xx, yy *int) *int { // ERROR "leaking param: xx to result ~r2 level=0$" "leaking param: yy to result ~r2 level=0$" xx = yy return xx } @@ -84,7 +84,7 @@ func foo12(yyy **int) { // ERROR "leaking param: yyy$" // Must treat yyy as leaking because *yyy leaks, and the escape analysis // summaries in exported metadata do not distinguish these two cases. -func foo13(yyy **int) { // ERROR "leaking param: yyy$" +func foo13(yyy **int) { // ERROR "leaking param content: yyy$" *xxx = *yyy } @@ -121,7 +121,7 @@ func NewBar() *Bar { return &Bar{42, nil} // ERROR "&Bar literal escapes to heap$" } -func NewBarp(x *int) *Bar { // ERROR "leaking param: x$" +func NewBarp(x *int) *Bar { // ERROR "leaking param: x to result ~r1 level=-1$" return &Bar{42, x} // ERROR "&Bar literal escapes to heap$" } @@ -133,25 +133,25 @@ func (b *Bar) NoLeak() int { // ERROR "\(\*Bar\).NoLeak b does not escape$" return *(b.ii) } -func (b *Bar) Leak() *int { // ERROR "leaking param: b to result ~r0$" +func (b *Bar) Leak() *int { // ERROR "leaking param: b to result ~r0 level=0$" return &b.i // ERROR "&b.i escapes to heap$" } -func (b *Bar) AlsoNoLeak() *int { // ERROR "\(\*Bar\).AlsoNoLeak leaking param b content to result ~r0$" +func (b *Bar) AlsoNoLeak() *int { // ERROR "leaking param: b to result ~r0 level=1$" return b.ii } -func (b Bar) AlsoLeak() *int { // ERROR "leaking param: b to result ~r0$" +func (b Bar) AlsoLeak() *int { // ERROR "leaking param: b to result ~r0 level=0$" return b.ii } -func (b Bar) LeaksToo() *int { // ERROR "leaking param: b to result ~r0$" +func (b Bar) LeaksToo() *int { // ERROR "leaking param: b to result ~r0 level=0$" v := 0 // ERROR "moved to heap: v$" b.ii = &v // ERROR "&v escapes to heap$" return b.ii } -func (b *Bar) LeaksABit() *int { // ERROR "\(\*Bar\).LeaksABit leaking param b content to result ~r0$" +func (b *Bar) LeaksABit() *int { // ERROR "leaking param: b to result ~r0 level=1$" v := 0 // ERROR "moved to heap: v$" b.ii = &v // ERROR "&v escapes to heap$" return b.ii @@ -180,11 +180,11 @@ func (b *Bar2) NoLeak() int { // ERROR "\(\*Bar2\).NoLeak b does not escape$" return b.i[0] } -func (b *Bar2) Leak() []int { // ERROR "leaking param: b to result ~r0$" +func (b *Bar2) Leak() []int { // ERROR "leaking param: b to result ~r0 level=0$" return b.i[:] // ERROR "b.i escapes to heap$" } -func (b *Bar2) AlsoNoLeak() []int { // ERROR "\(\*Bar2\).AlsoNoLeak leaking param b content to result ~r0$" +func (b *Bar2) AlsoNoLeak() []int { // ERROR "leaking param: b to result ~r0 level=1$" return b.ii[0:1] } @@ -319,7 +319,7 @@ func (f *Foo) foo45() { // ERROR "\(\*Foo\).foo45 f does not escape$" } // See foo13 above for explanation of why f leaks. -func (f *Foo) foo46() { // ERROR "leaking param: f$" +func (f *Foo) foo46() { // ERROR "leaking param content: f$" F.xx = f.xx } @@ -343,11 +343,11 @@ func indaddr1(x int) *int { // ERROR "moved to heap: x$" return &x // ERROR "&x escapes to heap$" } -func indaddr2(x *int) *int { // ERROR "leaking param: x to result ~r1$" +func indaddr2(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$" return *&x // ERROR "indaddr2 &x does not escape$" } -func indaddr3(x *int32) *int { // ERROR "leaking param: x to result ~r1$" +func indaddr3(x *int32) *int { // ERROR "leaking param: x to result ~r1 level=0$" return *(**int)(unsafe.Pointer(&x)) // ERROR "indaddr3 &x does not escape$" } @@ -374,11 +374,11 @@ func float64bitsptr(f float64) *uint64 { // ERROR "moved to heap: f$" return (*uint64)(unsafe.Pointer(&f)) // ERROR "&f escapes to heap$" } -func float64ptrbitsptr(f *float64) *uint64 { // ERROR "leaking param: f to result ~r1$" +func float64ptrbitsptr(f *float64) *uint64 { // ERROR "leaking param: f to result ~r1 level=0$" return (*uint64)(unsafe.Pointer(f)) } -func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r1$" +func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r1 level=0$" switch val := i.(type) { case *int: return val @@ -389,7 +389,7 @@ func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r1$" return nil } -func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r1$" +func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$" switch j := i; *j + 110 { case 12: return j @@ -401,7 +401,7 @@ func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r1$" } // assigning to an array element is like assigning to the array -func foo60(i *int) *int { // ERROR "leaking param: i to result ~r1$" +func foo60(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$" var a [12]*int a[0] = i return a[1] @@ -414,7 +414,7 @@ func foo60a(i *int) *int { // ERROR "foo60a i does not escape$" } // assigning to a struct field is like assigning to the struct -func foo61(i *int) *int { // ERROR "leaking param: i to result ~r1$" +func foo61(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$" type S struct { a, b *int } @@ -611,11 +611,11 @@ func foo74c() { } } -func myprint(y *int, x ...interface{}) *int { // ERROR "leaking param: y to result ~r2$" "myprint x does not escape$" +func myprint(y *int, x ...interface{}) *int { // ERROR "leaking param: y to result ~r2 level=0$" "myprint x does not escape$" return y } -func myprint1(y *int, x ...interface{}) *interface{} { // ERROR "leaking param: x to result ~r2$" "myprint1 y does not escape$" +func myprint1(y *int, x ...interface{}) *interface{} { // ERROR "leaking param: x to result ~r2 level=0$" "myprint1 y does not escape$" return &x[0] // ERROR "&x\[0\] escapes to heap$" } @@ -738,7 +738,7 @@ func foo81() *int { return nil } -func tee(p *int) (x, y *int) { return p, p } // ERROR "leaking param: p to result x$" "leaking param: p to result y$" +func tee(p *int) (x, y *int) { return p, p } // ERROR "leaking param: p to result x level=0$" "leaking param: p to result y level=0$" func noop(x, y *int) {} // ERROR "noop x does not escape$" "noop y does not escape$" @@ -762,7 +762,7 @@ type LimitedFooer struct { N int64 } -func LimitFooer(r Fooer, n int64) Fooer { // ERROR "leaking param: r$" +func LimitFooer(r Fooer, n int64) Fooer { // ERROR "leaking param: r to result ~r2 level=-1$" return &LimitedFooer{r, n} // ERROR "&LimitedFooer literal escapes to heap$" } @@ -774,7 +774,7 @@ func foo91(x *int) map[*int]*int { // ERROR "leaking param: x$" return map[*int]*int{x: nil} // ERROR "map\[\*int\]\*int literal escapes to heap$" } -func foo92(x *int) [2]*int { // ERROR "leaking param: x to result ~r1$" +func foo92(x *int) [2]*int { // ERROR "leaking param: x to result ~r1 level=0$" return [2]*int{x, nil} } @@ -808,7 +808,7 @@ func foo96(m []*int) *int { // ERROR "foo96 m does not escape$" } // does leak m -func foo97(m [1]*int) *int { // ERROR "leaking param: m to result ~r1$" +func foo97(m [1]*int) *int { // ERROR "leaking param: m to result ~r1 level=0$" return m[0] } @@ -818,7 +818,7 @@ func foo98(m map[int]*int) *int { // ERROR "foo98 m does not escape$" } // does leak m -func foo99(m *[1]*int) []*int { // ERROR "leaking param: m to result ~r1$" +func foo99(m *[1]*int) []*int { // ERROR "leaking param: m to result ~r1 level=0$" return m[:] } @@ -831,7 +831,7 @@ func foo100(m []*int) *int { // ERROR "foo100 m does not escape$" } // does leak m -func foo101(m [1]*int) *int { // ERROR "leaking param: m to result ~r1$" +func foo101(m [1]*int) *int { // ERROR "leaking param: m to result ~r1 level=0$" for _, v := range m { return v } @@ -899,22 +899,22 @@ func foo111(x *int) *int { // ERROR "leaking param: x$" return m[0] } -func foo112(x *int) *int { // ERROR "leaking param: x to result ~r1$" +func foo112(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$" m := [1]*int{x} return m[0] } -func foo113(x *int) *int { // ERROR "leaking param: x to result ~r1$" +func foo113(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$" m := Bar{ii: x} return m.ii } -func foo114(x *int) *int { // ERROR "leaking param: x to result ~r1$" +func foo114(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$" m := &Bar{ii: x} // ERROR "foo114 &Bar literal does not escape$" return m.ii } -func foo115(x *int) *int { // ERROR "leaking param: x to result ~r1$" +func foo115(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$" return (*int)(unsafe.Pointer(uintptr(unsafe.Pointer(x)) + 1)) } @@ -1525,7 +1525,7 @@ type U struct { s *string } -func (u *U) String() *string { // ERROR "\(\*U\).String leaking param u content to result ~r0$" +func (u *U) String() *string { // ERROR "leaking param: u to result ~r0 level=1$" return u.s } @@ -1533,8 +1533,9 @@ type V struct { s *string } -func NewV(u U) *V { // ERROR "leaking param: u$" - return &V{u.String()} // ERROR "&V literal escapes to heap$" "NewV u does not escape$" +// BAD -- level of leak ought to be 0 +func NewV(u U) *V { // ERROR "leaking param: u to result ~r1 level=-1" + return &V{u.String()} // ERROR "&V literal escapes to heap$" "NewV u does not escape" } func foo152() { @@ -1546,7 +1547,7 @@ func foo152() { // issue 8176 - &x in type switch body not marked as escaping -func foo153(v interface{}) *int { // ERROR "leaking param: v$" +func foo153(v interface{}) *int { // ERROR "leaking param: v to result ~r1 level=-1$" switch x := v.(type) { case int: // ERROR "moved to heap: x$" return &x // ERROR "&x escapes to heap$" @@ -1619,7 +1620,7 @@ func (b *Buffer) baz() { // ERROR "\(\*Buffer\).baz b does not escape$" b.str1 = b.str2[1:2] // ERROR "\(\*Buffer\).baz ignoring self-assignment to b.str1$" } -func (b *Buffer) bat() { // ERROR "leaking param: b$" +func (b *Buffer) bat() { // ERROR "leaking param content: b$" o := new(Buffer) // ERROR "new\(Buffer\) escapes to heap$" o.buf1 = b.buf1[1:2] sink = o // ERROR "o escapes to heap$" @@ -1803,7 +1804,7 @@ func issue10353() { issue10353a(x)() } -func issue10353a(x *int) func() { // ERROR "leaking param: x$" +func issue10353a(x *int) func() { // ERROR "leaking param: x to result ~r1 level=-1$" return func() { // ERROR "func literal escapes to heap$" println(*x) } diff --git a/test/escape2n.go b/test/escape2n.go index a414addc73..bf8c534a91 100644 --- a/test/escape2n.go +++ b/test/escape2n.go @@ -59,7 +59,7 @@ func foo8(xx, yy *int) int { // ERROR "foo8 xx does not escape$" "foo8 yy does n return *xx } -func foo9(xx, yy *int) *int { // ERROR "leaking param: xx to result ~r2$" "leaking param: yy to result ~r2$" +func foo9(xx, yy *int) *int { // ERROR "leaking param: xx to result ~r2 level=0$" "leaking param: yy to result ~r2 level=0$" xx = yy return xx } @@ -84,7 +84,7 @@ func foo12(yyy **int) { // ERROR "leaking param: yyy$" // Must treat yyy as leaking because *yyy leaks, and the escape analysis // summaries in exported metadata do not distinguish these two cases. -func foo13(yyy **int) { // ERROR "leaking param: yyy$" +func foo13(yyy **int) { // ERROR "leaking param content: yyy$" *xxx = *yyy } @@ -121,7 +121,7 @@ func NewBar() *Bar { return &Bar{42, nil} // ERROR "&Bar literal escapes to heap$" } -func NewBarp(x *int) *Bar { // ERROR "leaking param: x$" +func NewBarp(x *int) *Bar { // ERROR "leaking param: x to result ~r1 level=-1$" return &Bar{42, x} // ERROR "&Bar literal escapes to heap$" } @@ -133,25 +133,25 @@ func (b *Bar) NoLeak() int { // ERROR "\(\*Bar\).NoLeak b does not escape$" return *(b.ii) } -func (b *Bar) Leak() *int { // ERROR "leaking param: b to result ~r0$" +func (b *Bar) Leak() *int { // ERROR "leaking param: b to result ~r0 level=0$" return &b.i // ERROR "&b.i escapes to heap$" } -func (b *Bar) AlsoNoLeak() *int { // ERROR "\(\*Bar\).AlsoNoLeak leaking param b content to result ~r0$" +func (b *Bar) AlsoNoLeak() *int { // ERROR "leaking param: b to result ~r0 level=1$" return b.ii } -func (b Bar) AlsoLeak() *int { // ERROR "leaking param: b to result ~r0$" +func (b Bar) AlsoLeak() *int { // ERROR "leaking param: b to result ~r0 level=0$" return b.ii } -func (b Bar) LeaksToo() *int { // ERROR "leaking param: b to result ~r0$" +func (b Bar) LeaksToo() *int { // ERROR "leaking param: b to result ~r0 level=0$" v := 0 // ERROR "moved to heap: v$" b.ii = &v // ERROR "&v escapes to heap$" return b.ii } -func (b *Bar) LeaksABit() *int { // ERROR "\(\*Bar\).LeaksABit leaking param b content to result ~r0$" +func (b *Bar) LeaksABit() *int { // ERROR "leaking param: b to result ~r0 level=1$" v := 0 // ERROR "moved to heap: v$" b.ii = &v // ERROR "&v escapes to heap$" return b.ii @@ -180,11 +180,11 @@ func (b *Bar2) NoLeak() int { // ERROR "\(\*Bar2\).NoLeak b does not escape$" return b.i[0] } -func (b *Bar2) Leak() []int { // ERROR "leaking param: b to result ~r0$" +func (b *Bar2) Leak() []int { // ERROR "leaking param: b to result ~r0 level=0$" return b.i[:] // ERROR "b.i escapes to heap$" } -func (b *Bar2) AlsoNoLeak() []int { // ERROR "\(\*Bar2\).AlsoNoLeak leaking param b content to result ~r0$" +func (b *Bar2) AlsoNoLeak() []int { // ERROR "leaking param: b to result ~r0 level=1$" return b.ii[0:1] } @@ -319,7 +319,7 @@ func (f *Foo) foo45() { // ERROR "\(\*Foo\).foo45 f does not escape$" } // See foo13 above for explanation of why f leaks. -func (f *Foo) foo46() { // ERROR "leaking param: f$" +func (f *Foo) foo46() { // ERROR "leaking param content: f$" F.xx = f.xx } @@ -343,11 +343,11 @@ func indaddr1(x int) *int { // ERROR "moved to heap: x$" return &x // ERROR "&x escapes to heap$" } -func indaddr2(x *int) *int { // ERROR "leaking param: x to result ~r1$" +func indaddr2(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$" return *&x // ERROR "indaddr2 &x does not escape$" } -func indaddr3(x *int32) *int { // ERROR "leaking param: x to result ~r1$" +func indaddr3(x *int32) *int { // ERROR "leaking param: x to result ~r1 level=0$" return *(**int)(unsafe.Pointer(&x)) // ERROR "indaddr3 &x does not escape$" } @@ -374,11 +374,11 @@ func float64bitsptr(f float64) *uint64 { // ERROR "moved to heap: f$" return (*uint64)(unsafe.Pointer(&f)) // ERROR "&f escapes to heap$" } -func float64ptrbitsptr(f *float64) *uint64 { // ERROR "leaking param: f to result ~r1$" +func float64ptrbitsptr(f *float64) *uint64 { // ERROR "leaking param: f to result ~r1 level=0$" return (*uint64)(unsafe.Pointer(f)) } -func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r1$" +func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r1 level=0$" switch val := i.(type) { case *int: return val @@ -389,7 +389,7 @@ func typesw(i interface{}) *int { // ERROR "leaking param: i to result ~r1$" return nil } -func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r1$" +func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$" switch j := i; *j + 110 { case 12: return j @@ -401,7 +401,7 @@ func exprsw(i *int) *int { // ERROR "leaking param: i to result ~r1$" } // assigning to an array element is like assigning to the array -func foo60(i *int) *int { // ERROR "leaking param: i to result ~r1$" +func foo60(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$" var a [12]*int a[0] = i return a[1] @@ -414,7 +414,7 @@ func foo60a(i *int) *int { // ERROR "foo60a i does not escape$" } // assigning to a struct field is like assigning to the struct -func foo61(i *int) *int { // ERROR "leaking param: i to result ~r1$" +func foo61(i *int) *int { // ERROR "leaking param: i to result ~r1 level=0$" type S struct { a, b *int } @@ -611,11 +611,11 @@ func foo74c() { } } -func myprint(y *int, x ...interface{}) *int { // ERROR "leaking param: y to result ~r2$" "myprint x does not escape$" +func myprint(y *int, x ...interface{}) *int { // ERROR "leaking param: y to result ~r2 level=0$" "myprint x does not escape$" return y } -func myprint1(y *int, x ...interface{}) *interface{} { // ERROR "leaking param: x to result ~r2$" "myprint1 y does not escape$" +func myprint1(y *int, x ...interface{}) *interface{} { // ERROR "leaking param: x to result ~r2 level=0$" "myprint1 y does not escape$" return &x[0] // ERROR "&x\[0\] escapes to heap$" } @@ -738,7 +738,7 @@ func foo81() *int { return nil } -func tee(p *int) (x, y *int) { return p, p } // ERROR "leaking param: p to result x$" "leaking param: p to result y$" +func tee(p *int) (x, y *int) { return p, p } // ERROR "leaking param: p to result x level=0$" "leaking param: p to result y level=0$" func noop(x, y *int) {} // ERROR "noop x does not escape$" "noop y does not escape$" @@ -762,7 +762,7 @@ type LimitedFooer struct { N int64 } -func LimitFooer(r Fooer, n int64) Fooer { // ERROR "leaking param: r$" +func LimitFooer(r Fooer, n int64) Fooer { // ERROR "leaking param: r to result ~r2 level=-1$" return &LimitedFooer{r, n} // ERROR "&LimitedFooer literal escapes to heap$" } @@ -774,7 +774,7 @@ func foo91(x *int) map[*int]*int { // ERROR "leaking param: x$" return map[*int]*int{x: nil} // ERROR "map\[\*int\]\*int literal escapes to heap$" } -func foo92(x *int) [2]*int { // ERROR "leaking param: x to result ~r1$" +func foo92(x *int) [2]*int { // ERROR "leaking param: x to result ~r1 level=0$" return [2]*int{x, nil} } @@ -808,7 +808,7 @@ func foo96(m []*int) *int { // ERROR "foo96 m does not escape$" } // does leak m -func foo97(m [1]*int) *int { // ERROR "leaking param: m to result ~r1$" +func foo97(m [1]*int) *int { // ERROR "leaking param: m to result ~r1 level=0$" return m[0] } @@ -818,7 +818,7 @@ func foo98(m map[int]*int) *int { // ERROR "foo98 m does not escape$" } // does leak m -func foo99(m *[1]*int) []*int { // ERROR "leaking param: m to result ~r1$" +func foo99(m *[1]*int) []*int { // ERROR "leaking param: m to result ~r1 level=0$" return m[:] } @@ -831,7 +831,7 @@ func foo100(m []*int) *int { // ERROR "foo100 m does not escape$" } // does leak m -func foo101(m [1]*int) *int { // ERROR "leaking param: m to result ~r1$" +func foo101(m [1]*int) *int { // ERROR "leaking param: m to result ~r1 level=0$" for _, v := range m { return v } @@ -899,22 +899,22 @@ func foo111(x *int) *int { // ERROR "leaking param: x$" return m[0] } -func foo112(x *int) *int { // ERROR "leaking param: x to result ~r1$" +func foo112(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$" m := [1]*int{x} return m[0] } -func foo113(x *int) *int { // ERROR "leaking param: x to result ~r1$" +func foo113(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$" m := Bar{ii: x} return m.ii } -func foo114(x *int) *int { // ERROR "leaking param: x to result ~r1$" +func foo114(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$" m := &Bar{ii: x} // ERROR "foo114 &Bar literal does not escape$" return m.ii } -func foo115(x *int) *int { // ERROR "leaking param: x to result ~r1$" +func foo115(x *int) *int { // ERROR "leaking param: x to result ~r1 level=0$" return (*int)(unsafe.Pointer(uintptr(unsafe.Pointer(x)) + 1)) } @@ -1525,7 +1525,7 @@ type U struct { s *string } -func (u *U) String() *string { // ERROR "\(\*U\).String leaking param u content to result ~r0$" +func (u *U) String() *string { // ERROR "leaking param: u to result ~r0 level=1$" return u.s } @@ -1533,8 +1533,9 @@ type V struct { s *string } -func NewV(u U) *V { // ERROR "leaking param: u$" - return &V{u.String()} // ERROR "&V literal escapes to heap$" "NewV u does not escape$" +// BAD -- level of leak ought to be 0 +func NewV(u U) *V { // ERROR "leaking param: u to result ~r1 level=-1" + return &V{u.String()} // ERROR "&V literal escapes to heap$" "NewV u does not escape" } func foo152() { @@ -1546,7 +1547,7 @@ func foo152() { // issue 8176 - &x in type switch body not marked as escaping -func foo153(v interface{}) *int { // ERROR "leaking param: v$" +func foo153(v interface{}) *int { // ERROR "leaking param: v to result ~r1 level=-1$" switch x := v.(type) { case int: // ERROR "moved to heap: x$" return &x // ERROR "&x escapes to heap$" @@ -1619,7 +1620,7 @@ func (b *Buffer) baz() { // ERROR "\(\*Buffer\).baz b does not escape$" b.str1 = b.str2[1:2] // ERROR "\(\*Buffer\).baz ignoring self-assignment to b.str1$" } -func (b *Buffer) bat() { // ERROR "leaking param: b$" +func (b *Buffer) bat() { // ERROR "leaking param content: b$" o := new(Buffer) // ERROR "new\(Buffer\) escapes to heap$" o.buf1 = b.buf1[1:2] sink = o // ERROR "o escapes to heap$" @@ -1803,7 +1804,7 @@ func issue10353() { issue10353a(x)() } -func issue10353a(x *int) func() { // ERROR "leaking param: x$" +func issue10353a(x *int) func() { // ERROR "leaking param: x to result ~r1 level=-1$" return func() { // ERROR "func literal escapes to heap$" println(*x) } diff --git a/test/escape_array.go b/test/escape_array.go new file mode 100644 index 0000000000..ac51fe7ca6 --- /dev/null +++ b/test/escape_array.go @@ -0,0 +1,72 @@ +// errorcheck -0 -m -l + +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Test escape analysis for function parameters. + +// In this test almost everything is BAD except the simplest cases +// where input directly flows to output. + +package foo + +var Ssink *string + +type U [2]*string + +func bar(a, b *string) U { // ERROR "leaking param: a to result ~r2 level=0$" "leaking param: b to result ~r2 level=0$" + return U{a, b} +} + +func foo(x U) U { // ERROR "leaking param: x to result ~r1 level=0$" + return U{x[1], x[0]} +} + +func bff(a, b *string) U { // ERROR "leaking param: a to result ~r2 level=0$" "leaking param: b to result ~r2 level=0$" + return foo(foo(bar(a, b))) +} + +func tbff1() *string { + a := "cat" + b := "dog" // ERROR "moved to heap: b$" + u := bff(&a, &b) // ERROR "tbff1 &a does not escape$" "tbff1 &b does not escape$" + _ = u[0] + return &b // ERROR "&b escapes to heap$" +} + +// BAD: need fine-grained analysis to track u[0] and u[1] differently. +func tbff2() *string { + a := "cat" // ERROR "moved to heap: a$" + b := "dog" // ERROR "moved to heap: b$" + u := bff(&a, &b) // ERROR "&a escapes to heap$" "&b escapes to heap$" + _ = u[0] + return u[1] +} + +func car(x U) *string { // ERROR "leaking param: x to result ~r1 level=0$" + return x[0] +} + +// BAD: need fine-grained analysis to track x[0] and x[1] differently. +func fun(x U, y *string) *string { // ERROR "leaking param: x to result ~r2 level=0$" "leaking param: y to result ~r2 level=0$" + x[0] = y + return x[1] +} + +func fup(x *U, y *string) *string { // ERROR "leaking param: x to result ~r2 level=1$" "leaking param: y$" + x[0] = y // leaking y to heap is intended + return x[1] +} + +// BAD: would be nice to record that *y (content) is what leaks, not y itself +func fum(x *U, y **string) *string { // ERROR "leaking param: x to result ~r2 level=1$" "leaking param content: y$" + x[0] = *y + return x[1] +} + +// BAD: would be nice to record that y[0] (content) is what leaks, not y itself +func fuo(x *U, y *U) *string { // ERROR "leaking param: x to result ~r2 level=1$" "leaking param content: y$" + x[0] = y[0] + return x[1] +} diff --git a/test/escape_calls.go b/test/escape_calls.go new file mode 100644 index 0000000000..f289670091 --- /dev/null +++ b/test/escape_calls.go @@ -0,0 +1,44 @@ +// errorcheck -0 -m -l + +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Test escape analysis for function parameters. + +// In this test almost everything is BAD except the simplest cases +// where input directly flows to output. + +package foo + +func f(buf []byte) []byte { // ERROR "leaking param: buf to result ~r1 level=0$" + return buf +} + +func g(*byte) string + +func h(e int) { + var x [32]byte // ERROR "moved to heap: x$" + g(&f(x[:])[0]) // ERROR "&f\(x\[:\]\)\[0\] escapes to heap$" "x escapes to heap$" +} + +type Node struct { + s string + left, right *Node +} + +func walk(np **Node) int { // ERROR "leaking param content: np" + n := *np + w := len(n.s) + if n == nil { + return 0 + } + wl := walk(&n.left) // ERROR "walk &n.left does not escape" + wr := walk(&n.right) // ERROR "walk &n.right does not escape" + if wl < wr { + n.left, n.right = n.right, n.left + wl, wr = wr, wl + } + *np = n + return w + wl + wr +} diff --git a/test/escape_closure.go b/test/escape_closure.go index 0a5f326dd3..4cdb06e4c5 100644 --- a/test/escape_closure.go +++ b/test/escape_closure.go @@ -131,7 +131,7 @@ func ClosureCallArgs14() { x := 0 // ERROR "moved to heap: x" // BAD: &x should not escape here p := &x // ERROR "moved to heap: p" "&x escapes to heap" - _ = func(p **int) *int { // ERROR "leaking param p content to result ~r1" "func literal does not escape" + _ = func(p **int) *int { // ERROR "leaking param: p to result ~r1 level=1" "func literal does not escape" return *p // BAD: p should not escape here }(&p) // ERROR "&p escapes to heap" @@ -140,7 +140,7 @@ func ClosureCallArgs14() { func ClosureCallArgs15() { x := 0 // ERROR "moved to heap: x" p := &x // ERROR "moved to heap: p" "&x escapes to heap" - sink = func(p **int) *int { // ERROR "leaking param p content to result ~r1" "func literal does not escape" + sink = func(p **int) *int { // ERROR "leaking param: p to result ~r1 level=1" "func literal does not escape" return *p // BAD: p should not escape here }(&p) // ERROR "&p escapes to heap" "\(func literal\)\(&p\) escapes to heap" diff --git a/test/escape_field.go b/test/escape_field.go index dcf8a31d2b..16d1e741b8 100644 --- a/test/escape_field.go +++ b/test/escape_field.go @@ -23,7 +23,7 @@ type Y struct { func field0() { i := 0 // ERROR "moved to heap: i$" var x X - x.p1 = &i // ERROR "&i escapes to heap$" + x.p1 = &i // ERROR "&i escapes to heap$" sink = x.p1 // ERROR "x\.p1 escapes to heap" } @@ -31,7 +31,7 @@ func field1() { i := 0 // ERROR "moved to heap: i$" var x X // BAD: &i should not escape - x.p1 = &i // ERROR "&i escapes to heap$" + x.p1 = &i // ERROR "&i escapes to heap$" sink = x.p2 // ERROR "x\.p2 escapes to heap" } @@ -39,7 +39,7 @@ func field3() { i := 0 // ERROR "moved to heap: i$" var x X x.p1 = &i // ERROR "&i escapes to heap$" - sink = x // ERROR "x escapes to heap" + sink = x // ERROR "x escapes to heap" } func field4() { @@ -54,22 +54,21 @@ func field5() { i := 0 // ERROR "moved to heap: i$" var x X // BAD: &i should not escape here - x.a[0] = &i // ERROR "&i escapes to heap$" + x.a[0] = &i // ERROR "&i escapes to heap$" sink = x.a[1] // ERROR "x\.a\[1\] escapes to heap" } // BAD: we are not leaking param x, only x.p2 -func field6(x *X) { // ERROR "leaking param: x$" +func field6(x *X) { // ERROR "leaking param content: x$" sink = x.p2 // ERROR "x\.p2 escapes to heap" } func field6a() { - i := 0 // ERROR "moved to heap: i$" - var x X // ERROR "moved to heap: x$" + i := 0 // ERROR "moved to heap: i$" + var x X // BAD: &i should not escape - x.p1 = &i // ERROR "&i escapes to heap$" - // BAD: &x should not escape - field6(&x) // ERROR "&x escapes to heap$" + x.p1 = &i // ERROR "&i escapes to heap$" + field6(&x) // ERROR "field6a &x does not escape" } func field7() { @@ -116,40 +115,40 @@ func field10() { func field11() { i := 0 // ERROR "moved to heap: i$" x := X{p1: &i} // ERROR "&i escapes to heap$" - sink = x.p1 // ERROR "x\.p1 escapes to heap" + sink = x.p1 // ERROR "x\.p1 escapes to heap" } func field12() { i := 0 // ERROR "moved to heap: i$" // BAD: &i should not escape x := X{p1: &i} // ERROR "&i escapes to heap$" - sink = x.p2 // ERROR "x\.p2 escapes to heap" + sink = x.p2 // ERROR "x\.p2 escapes to heap" } func field13() { i := 0 // ERROR "moved to heap: i$" x := &X{p1: &i} // ERROR "&i escapes to heap$" "field13 &X literal does not escape$" - sink = x.p1 // ERROR "x\.p1 escapes to heap" + sink = x.p1 // ERROR "x\.p1 escapes to heap" } func field14() { i := 0 // ERROR "moved to heap: i$" // BAD: &i should not escape x := &X{p1: &i} // ERROR "&i escapes to heap$" "field14 &X literal does not escape$" - sink = x.p2 // ERROR "x\.p2 escapes to heap" + sink = x.p2 // ERROR "x\.p2 escapes to heap" } func field15() { i := 0 // ERROR "moved to heap: i$" x := &X{p1: &i} // ERROR "&X literal escapes to heap$" "&i escapes to heap$" - sink = x // ERROR "x escapes to heap" + sink = x // ERROR "x escapes to heap" } func field16() { i := 0 // ERROR "moved to heap: i$" var x X // BAD: &i should not escape - x.p1 = &i // ERROR "&i escapes to heap$" + x.p1 = &i // ERROR "&i escapes to heap$" var iface interface{} = x // ERROR "x escapes to heap" x1 := iface.(X) sink = x1.p2 // ERROR "x1\.p2 escapes to heap" @@ -158,7 +157,7 @@ func field16() { func field17() { i := 0 // ERROR "moved to heap: i$" var x X - x.p1 = &i // ERROR "&i escapes to heap$" + x.p1 = &i // ERROR "&i escapes to heap$" var iface interface{} = x // ERROR "x escapes to heap" x1 := iface.(X) sink = x1.p1 // ERROR "x1\.p1 escapes to heap" @@ -168,8 +167,8 @@ func field18() { i := 0 // ERROR "moved to heap: i$" var x X // BAD: &i should not escape - x.p1 = &i // ERROR "&i escapes to heap$" + x.p1 = &i // ERROR "&i escapes to heap$" var iface interface{} = x // ERROR "x escapes to heap" - y, _ := iface.(Y) // Put X, but extracted Y. The cast will fail, so y is zero initialized. - sink = y // ERROR "y escapes to heap" + y, _ := iface.(Y) // Put X, but extracted Y. The cast will fail, so y is zero initialized. + sink = y // ERROR "y escapes to heap" } diff --git a/test/escape_indir.go b/test/escape_indir.go index 7c06ceb5f8..fe03c3fb1b 100644 --- a/test/escape_indir.go +++ b/test/escape_indir.go @@ -54,14 +54,14 @@ func constptr1() { i := 0 // ERROR "moved to heap: i" x := &ConstPtr{} // ERROR "&ConstPtr literal escapes to heap" x.p = &i // ERROR "&i escapes to heap" - sink = x // ERROR "x escapes to heap" + sink = x // ERROR "x escapes to heap" } func constptr2() { i := 0 // ERROR "moved to heap: i" x := &ConstPtr{} // ERROR "&ConstPtr literal does not escape" x.p = &i // ERROR "&i escapes to heap" - sink = *x// ERROR "\*x escapes to heap" + sink = *x // ERROR "\*x escapes to heap" } func constptr4() *ConstPtr { @@ -78,7 +78,7 @@ func constptr5() *ConstPtr { } // BAD: p should not escape here -func constptr6(p *ConstPtr) { // ERROR "leaking param: p" +func constptr6(p *ConstPtr) { // ERROR "leaking param content: p" p1 := &ConstPtr{} // ERROR "&ConstPtr literal does not escape" *p1 = *p _ = p1 @@ -151,3 +151,10 @@ func foo2() { i := 0 // ERROR "moved to heap: i" *p = &i // ERROR "&i escapes to heap" } + +var global *byte + +func f() { + var x byte // ERROR "moved to heap: x" + global = &*&x // ERROR "&\(\*\(&x\)\) escapes to heap" "&x escapes to heap" +} diff --git a/test/escape_level.go b/test/escape_level.go index 581e4a95cb..867c81ae52 100644 --- a/test/escape_level.go +++ b/test/escape_level.go @@ -27,18 +27,18 @@ func level1() { } func level2() { - i := 0 // ERROR "moved to heap: i" - p0 := &i // ERROR "moved to heap: p0" "&i escapes to heap" - p1 := &p0 // ERROR "&p0 escapes to heap" - p2 := &p1 // ERROR "&p1 does not escape" + i := 0 // ERROR "moved to heap: i" + p0 := &i // ERROR "moved to heap: p0" "&i escapes to heap" + p1 := &p0 // ERROR "&p0 escapes to heap" + p2 := &p1 // ERROR "&p1 does not escape" sink = *p2 // ERROR "\*p2 escapes to heap" } func level3() { - i := 0 // ERROR "moved to heap: i" - p0 := &i // ERROR "&i escapes to heap" - p1 := &p0 // ERROR "&p0 does not escape" - p2 := &p1 // ERROR "&p1 does not escape" + i := 0 // ERROR "moved to heap: i" + p0 := &i // ERROR "&i escapes to heap" + p1 := &p0 // ERROR "&p0 does not escape" + p2 := &p1 // ERROR "&p1 does not escape" sink = **p2 // ERROR "\* \(\*p2\) escapes to heap" } @@ -67,10 +67,10 @@ func level6() { } func level7() { - i := 0 // ERROR "moved to heap: i" - p0 := &i // ERROR "moved to heap: p0" "&i escapes to heap" - // BAD: p0 should not escape here - p1 := &p0 // ERROR "&p0 escapes to heap" + i := 0 // ERROR "moved to heap: i" + p0 := &i // ERROR "&i escapes to heap" + p1 := &p0 // ERROR "&p0 does not escape" + // note *p1 == &i p2 := *p1 // ERROR "moved to heap: p2" sink = &p2 // ERROR "&p2 escapes to heap" } @@ -95,7 +95,7 @@ func level10() { i := 0 p0 := &i // ERROR "&i does not escape" p1 := *p0 - p2 := &p1 // ERROR "&p1 does not escape" + p2 := &p1 // ERROR "&p1 does not escape" sink = *p2 // ERROR "\*p2 escapes to heap" } diff --git a/test/escape_param.go b/test/escape_param.go index 91ad437d86..cfbcd51ca7 100644 --- a/test/escape_param.go +++ b/test/escape_param.go @@ -14,7 +14,7 @@ package escape var sink interface{} // in -> out -func param0(p *int) *int { // ERROR "leaking param: p to result ~r1$" +func param0(p *int) *int { // ERROR "leaking param: p to result ~r1" return p } @@ -29,7 +29,7 @@ func caller0b() { } // in, in -> out, out -func param1(p1, p2 *int) (*int, *int) { // ERROR "leaking param: p1 to result ~r2$" "leaking param: p2 to result ~r3$" +func param1(p1, p2 *int) (*int, *int) { // ERROR "leaking param: p1 to result ~r2" "leaking param: p2 to result ~r3" return p1, p2 } @@ -64,23 +64,23 @@ type Pair struct { p2 *int } -func param3(p *Pair) { // ERROR "leaking param: p$" +func param3(p *Pair) { // ERROR "leaking param content: p$" p.p1 = p.p2 } func caller3a() { i := 0 // ERROR "moved to heap: i$" j := 0 // ERROR "moved to heap: j$" - p := Pair{&i, &j} // ERROR "&i escapes to heap$" "&j escapes to heap$" "moved to heap: p$" - param3(&p) // ERROR "&p escapes to heap$" + p := Pair{&i, &j} // ERROR "&i escapes to heap$" "&j escapes to heap$" + param3(&p) // ERROR "caller3a &p does not escape" _ = p } func caller3b() { i := 0 // ERROR "moved to heap: i$" j := 0 // ERROR "moved to heap: j$" - p := Pair{&i, &j} // ERROR "&i escapes to heap$" "&j escapes to heap$" "moved to heap: p$" - param3(&p) // ERROR "&p escapes to heap$" + p := Pair{&i, &j} // ERROR "&i escapes to heap$" "&j escapes to heap$" + param3(&p) // ERROR "caller3b &p does not escape" sink = p // ERROR "p escapes to heap$" } @@ -114,27 +114,27 @@ func caller5() { } // *in -> heap -func param6(i ***int) { // ERROR "leaking param: i$" +func param6(i ***int) { // ERROR "leaking param content: i$" sink = *i // ERROR "\*i escapes to heap$" } func caller6a() { i := 0 // ERROR "moved to heap: i$" p := &i // ERROR "&i escapes to heap$" "moved to heap: p$" - p2 := &p // ERROR "&p escapes to heap$" "moved to heap: p2$" - param6(&p2) // ERROR "&p2 escapes to heap$" + p2 := &p // ERROR "&p escapes to heap$" + param6(&p2) // ERROR "caller6a &p2 does not escape" } // **in -> heap -func param7(i ***int) { // ERROR "leaking param: i$" +func param7(i ***int) { // ERROR "leaking param content: i$" sink = **i // ERROR "\* \(\*i\) escapes to heap" } func caller7() { i := 0 // ERROR "moved to heap: i$" p := &i // ERROR "&i escapes to heap$" "moved to heap: p$" - p2 := &p // ERROR "&p escapes to heap$" "moved to heap: p2$" - param7(&p2) // ERROR "&p2 escapes to heap$" + p2 := &p // ERROR "&p escapes to heap$" + param7(&p2) // ERROR "caller7 &p2 does not escape" } // **in -> heap @@ -149,14 +149,14 @@ func caller8() { } // *in -> out -func param9(p ***int) **int { // ERROR "param9 leaking param p content to result ~r1$" +func param9(p ***int) **int { // ERROR "leaking param: p to result ~r1 level=1" return *p } func caller9a() { - i := 0 // ERROR "moved to heap: i$" - p := &i // ERROR "&i escapes to heap$" "moved to heap: p$" - p2 := &p // ERROR "&p escapes to heap$" + i := 0 + p := &i // ERROR "caller9a &i does not escape" + p2 := &p // ERROR "caller9a &p does not escape" _ = param9(&p2) // ERROR "caller9a &p2 does not escape$" } @@ -168,33 +168,33 @@ func caller9b() { } // **in -> out -func param10(p ***int) *int { // ERROR "param10 leaking param p content to result ~r1$" +func param10(p ***int) *int { // ERROR "leaking param: p to result ~r1 level=2" return **p } func caller10a() { - i := 0 // ERROR "moved to heap: i$" - p := &i // ERROR "&i escapes to heap$" "moved to heap: p$" - p2 := &p // ERROR "&p escapes to heap$" + i := 0 + p := &i // ERROR "caller10a &i does not escape" + p2 := &p // ERROR "caller10a &p does not escape" _ = param10(&p2) // ERROR "caller10a &p2 does not escape$" } func caller10b() { i := 0 // ERROR "moved to heap: i$" - p := &i // ERROR "&i escapes to heap$" "moved to heap: p$" - p2 := &p // ERROR "&p escapes to heap$" + p := &i // ERROR "&i escapes to heap$" + p2 := &p // ERROR "caller10b &p does not escape$" sink = param10(&p2) // ERROR "caller10b &p2 does not escape$" "param10\(&p2\) escapes to heap" } -// &in -> out +// in escapes to heap (address of param taken and returned) func param11(i **int) ***int { // ERROR "moved to heap: i$" return &i // ERROR "&i escapes to heap$" } func caller11a() { - i := 0 // ERROR "moved to heap: i$" - p := &i // ERROR "&i escapes to heap$" "moved to heap: p$" - _ = param11(&p) // ERROR "&p escapes to heap$" + i := 0 // ERROR "moved to heap: i" + p := &i // ERROR "moved to heap: p" "&i escapes to heap" + _ = param11(&p) // ERROR "&p escapes to heap" } func caller11b() { @@ -203,10 +203,17 @@ func caller11b() { sink = param11(&p) // ERROR "&p escapes to heap$" "param11\(&p\) escapes to heap" } -func caller11c() { +func caller11c() { // GOOD i := 0 // ERROR "moved to heap: i$" - p := &i // ERROR "&i escapes to heap$" "moved to heap: p$" - sink = *param11(&p) // ERROR "&p escapes to heap$" "\*param11\(&p\) escapes to heap" + p := &i // ERROR "moved to heap: p" "&i escapes to heap" + sink = *param11(&p) // ERROR "&p escapes to heap" "\*param11\(&p\) escapes to heap" +} + +func caller11d() { + i := 0 // ERROR "moved to heap: i$" + p := &i // ERROR "&i escapes to heap" "moved to heap: p" + p2 := &p // ERROR "&p escapes to heap" + sink = param11(p2) // ERROR "param11\(p2\) escapes to heap" } // &in -> rcvr @@ -324,3 +331,23 @@ func caller13h() { v.param13(&i) // ERROR "&i escapes to heap$" sink = **v.p // ERROR "\* \(\*v\.p\) escapes to heap" } + +type Node struct { + p *Node +} + +var Sink *Node + +func f(x *Node) { // ERROR "leaking param content: x" + Sink = &Node{x.p} // ERROR "&Node literal escapes to heap" +} + +func g(x *Node) *Node { // ERROR "leaking param: x to result ~r1 level=0" + return &Node{x.p} // ERROR "&Node literal escapes to heap" +} + +func h(x *Node) { // ERROR "leaking param: x" + y := &Node{x} // ERROR "h &Node literal does not escape" + Sink = g(y) + f(y) +} diff --git a/test/escape_struct_param1.go b/test/escape_struct_param1.go new file mode 100644 index 0000000000..e30e327acd --- /dev/null +++ b/test/escape_struct_param1.go @@ -0,0 +1,298 @@ +// errorcheck -0 -m -l + +// 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. + +// Test escape analysis for *struct function parameters. +// Note companion strict_param2 checks struct function parameters with similar tests. + +package notmain + +var Ssink *string + +type U struct { + _sp *string + _spp **string +} + +type V struct { + _u U + _up *U + _upp **U +} + +func (u *U) SP() *string { // ERROR "leaking param: u to result ~r0 level=1$" + return u._sp +} + +func (u *U) SPP() **string { // ERROR "leaking param: u to result ~r0 level=1$" + return u._spp +} + +func (u *U) SPPi() *string { // ERROR "leaking param: u to result ~r0 level=2$" + return *u._spp +} + +func tSPPi() { + s := "cat" // ERROR "moved to heap: s$" + ps := &s // ERROR "&s escapes to heap$" + pps := &ps // ERROR "tSPPi &ps does not escape$" + pu := &U{ps, pps} // ERROR "tSPPi &U literal does not escape$" + Ssink = pu.SPPi() +} + +func tiSPP() { + s := "cat" // ERROR "moved to heap: s$" + ps := &s // ERROR "&s escapes to heap$" + pps := &ps // ERROR "tiSPP &ps does not escape$" + pu := &U{ps, pps} // ERROR "tiSPP &U literal does not escape$" + Ssink = *pu.SPP() +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of ps +func tSP() { + s := "cat" // ERROR "moved to heap: s$" + ps := &s // ERROR "&s escapes to heap$" "moved to heap: ps$" + pps := &ps // ERROR "&ps escapes to heap$" + pu := &U{ps, pps} // ERROR "tSP &U literal does not escape$" + Ssink = pu.SP() +} + +func (v *V) u() U { // ERROR "leaking param: v to result ~r0 level=1$" + return v._u +} + +func (v *V) UP() *U { // ERROR "leaking param: v to result ~r0 level=1$" + return v._up +} + +func (v *V) UPP() **U { // ERROR "leaking param: v to result ~r0 level=1$" + return v._upp +} + +func (v *V) UPPia() *U { // ERROR "leaking param: v to result ~r0 level=2$" + return *v._upp +} + +func (v *V) UPPib() *U { // ERROR "leaking param: v to result ~r0 level=2$" + return *v.UPP() +} + +func (v *V) USPa() *string { // ERROR "leaking param: v to result ~r0 level=1$" + return v._u._sp +} + +func (v *V) USPb() *string { // ERROR "leaking param: v to result ~r0 level=1$" + return v.u()._sp +} + +func (v *V) USPPia() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return *v._u._spp +} + +func (v *V) USPPib() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return v._u.SPPi() // ERROR "\(\*V\).USPPib v._u does not escape$" +} + +func (v *V) UPiSPa() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return v._up._sp +} + +func (v *V) UPiSPb() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return v._up.SP() +} + +func (v *V) UPiSPc() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return v.UP()._sp +} + +func (v *V) UPiSPd() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return v.UP().SP() +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 +func tUPiSPa() { + s1 := "ant" + s2 := "bat" // ERROR "moved to heap: s2$" + s3 := "cat" // ERROR "moved to heap: s3$" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "&s2 escapes to heap$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" "moved to heap: ps4$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPa &ps2 does not escape$" "tUPiSPa &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "&ps4 escapes to heap$" "&s3 escapes to heap$" "tUPiSPa &U literal does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$" "&ps6 escapes to heap$" "&s5 escapes to heap$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPa &V literal does not escape$" "tUPiSPa &u3 does not escape$" + Ssink = v.UPiSPa() // Ssink = &s3 (only &s3 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 +func tUPiSPb() { + s1 := "ant" + s2 := "bat" // ERROR "moved to heap: s2$" + s3 := "cat" // ERROR "moved to heap: s3$" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "&s2 escapes to heap$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" "moved to heap: ps4$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPb &ps2 does not escape$" "tUPiSPb &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "&ps4 escapes to heap$" "&s3 escapes to heap$" "tUPiSPb &U literal does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$" "&ps6 escapes to heap$" "&s5 escapes to heap$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPb &V literal does not escape$" "tUPiSPb &u3 does not escape$" + Ssink = v.UPiSPb() // Ssink = &s3 (only &s3 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 +func tUPiSPc() { + s1 := "ant" + s2 := "bat" // ERROR "moved to heap: s2$" + s3 := "cat" // ERROR "moved to heap: s3$" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "&s2 escapes to heap$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" "moved to heap: ps4$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPc &ps2 does not escape$" "tUPiSPc &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "&ps4 escapes to heap$" "&s3 escapes to heap$" "tUPiSPc &U literal does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$" "&ps6 escapes to heap$" "&s5 escapes to heap$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPc &V literal does not escape$" "tUPiSPc &u3 does not escape$" + Ssink = v.UPiSPc() // Ssink = &s3 (only &s3 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 +func tUPiSPd() { + s1 := "ant" + s2 := "bat" // ERROR "moved to heap: s2$" + s3 := "cat" // ERROR "moved to heap: s3$" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "&s2 escapes to heap$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" "moved to heap: ps4$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPd &ps2 does not escape$" "tUPiSPd &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "&ps4 escapes to heap$" "&s3 escapes to heap$" "tUPiSPd &U literal does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$" "&ps6 escapes to heap$" "&s5 escapes to heap$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPd &V literal does not escape$" "tUPiSPd &u3 does not escape$" + Ssink = v.UPiSPd() // Ssink = &s3 (only &s3 really escapes) +} + +func (v V) UPiSPPia() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return *v._up._spp +} + +func (v V) UPiSPPib() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return v._up.SPPi() +} + +func (v V) UPiSPPic() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return *v.UP()._spp // ERROR "V.UPiSPPic v does not escape$" +} + +func (v V) UPiSPPid() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return v.UP().SPPi() // ERROR "V.UPiSPPid v does not escape$" +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 +func tUPiSPPia() { + s1 := "ant" + s2 := "bat" + s3 := "cat" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "tUPiSPPia &s2 does not escape$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPPia &ps2 does not escape$" "tUPiSPPia &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "tUPiSPPia &U literal does not escape$" "tUPiSPPia &ps4 does not escape$" "tUPiSPPia &s3 does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&ps6 escapes to heap$" "&s5 escapes to heap$" "tUPiSPPia &U literal does not escape$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPPia &V literal does not escape$" "tUPiSPPia &u3 does not escape$" + Ssink = v.UPiSPPia() // Ssink = *&ps4 = &s4 (only &s4 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 +func tUPiSPPib() { + s1 := "ant" + s2 := "bat" + s3 := "cat" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "tUPiSPPib &s2 does not escape$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPPib &ps2 does not escape$" "tUPiSPPib &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "tUPiSPPib &U literal does not escape$" "tUPiSPPib &ps4 does not escape$" "tUPiSPPib &s3 does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&ps6 escapes to heap$" "&s5 escapes to heap$" "tUPiSPPib &U literal does not escape$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPPib &V literal does not escape$" "tUPiSPPib &u3 does not escape$" + Ssink = v.UPiSPPib() // Ssink = *&ps4 = &s4 (only &s4 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 +func tUPiSPPic() { + s1 := "ant" + s2 := "bat" + s3 := "cat" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "tUPiSPPic &s2 does not escape$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPPic &ps2 does not escape$" "tUPiSPPic &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "tUPiSPPic &U literal does not escape$" "tUPiSPPic &ps4 does not escape$" "tUPiSPPic &s3 does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&ps6 escapes to heap$" "&s5 escapes to heap$" "tUPiSPPic &U literal does not escape$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPPic &V literal does not escape$" "tUPiSPPic &u3 does not escape$" + Ssink = v.UPiSPPic() // Ssink = *&ps4 = &s4 (only &s4 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 +func tUPiSPPid() { + s1 := "ant" + s2 := "bat" + s3 := "cat" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "tUPiSPPid &s2 does not escape$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPPid &ps2 does not escape$" "tUPiSPPid &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "tUPiSPPid &U literal does not escape$" "tUPiSPPid &ps4 does not escape$" "tUPiSPPid &s3 does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&ps6 escapes to heap$" "&s5 escapes to heap$" "tUPiSPPid &U literal does not escape$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPPid &V literal does not escape$" "tUPiSPPid &u3 does not escape$" + Ssink = v.UPiSPPid() // Ssink = *&ps4 = &s4 (only &s4 really escapes) +} + +func (v *V) UPPiSPPia() *string { // ERROR "leaking param: v to result ~r0 level=4$" + return *(*v._upp)._spp +} + +// This test isolates the one value that needs to escape, not because +// it distinguishes fields but because it knows that &s6 is the only +// value reachable by two indirects from v. +// The test depends on the level cap in the escape analysis tags +// being able to encode that fact. +func tUPPiSPPia() { + s1 := "ant" + s2 := "bat" + s3 := "cat" + s4 := "dog" + s5 := "emu" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "tUPPiSPPia &s2 does not escape$" + ps4 := &s4 // ERROR "tUPPiSPPia &s4 does not escape$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" + u1 := U{&s1, &ps2} // ERROR "tUPPiSPPia &ps2 does not escape$" "tUPPiSPPia &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "tUPPiSPPia &U literal does not escape$" "tUPPiSPPia &ps4 does not escape$" "tUPPiSPPia &s3 does not escape$" + u3 := &U{&s5, &ps6} // ERROR "tUPPiSPPia &U literal does not escape$" "tUPPiSPPia &ps6 does not escape$" "tUPPiSPPia &s5 does not escape$" + v := &V{u1, u2, &u3} // ERROR "tUPPiSPPia &V literal does not escape$" "tUPPiSPPia &u3 does not escape$" + Ssink = v.UPPiSPPia() // Ssink = *&ps6 = &s6 (only &s6 really escapes) +} diff --git a/test/escape_struct_param2.go b/test/escape_struct_param2.go new file mode 100644 index 0000000000..c10c336495 --- /dev/null +++ b/test/escape_struct_param2.go @@ -0,0 +1,298 @@ +// errorcheck -0 -m -l + +// 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. + +// Test escape analysis for struct function parameters. +// Note companion strict_param1 checks *struct function parameters with similar tests. + +package notmain + +var Ssink *string + +type U struct { + _sp *string + _spp **string +} + +type V struct { + _u U + _up *U + _upp **U +} + +func (u U) SP() *string { // ERROR "leaking param: u to result ~r0 level=0$" + return u._sp +} + +func (u U) SPP() **string { // ERROR "leaking param: u to result ~r0 level=0$" + return u._spp +} + +func (u U) SPPi() *string { // ERROR "leaking param: u to result ~r0 level=1$" + return *u._spp +} + +func tSPPi() { + s := "cat" // ERROR "moved to heap: s$" + ps := &s // ERROR "&s escapes to heap$" + pps := &ps // ERROR "tSPPi &ps does not escape$" + pu := &U{ps, pps} // ERROR "tSPPi &U literal does not escape$" + Ssink = pu.SPPi() +} + +func tiSPP() { + s := "cat" // ERROR "moved to heap: s$" + ps := &s // ERROR "&s escapes to heap$" + pps := &ps // ERROR "tiSPP &ps does not escape$" + pu := &U{ps, pps} // ERROR "tiSPP &U literal does not escape$" + Ssink = *pu.SPP() +} + +// BAD: need fine-grained analysis to avoid spurious escape of ps +func tSP() { + s := "cat" // ERROR "moved to heap: s$" + ps := &s // ERROR "&s escapes to heap$" "moved to heap: ps$" + pps := &ps // ERROR "&ps escapes to heap$" + pu := &U{ps, pps} // ERROR "tSP &U literal does not escape$" + Ssink = pu.SP() +} + +func (v V) u() U { // ERROR "leaking param: v to result ~r0 level=0$" + return v._u +} + +func (v V) UP() *U { // ERROR "leaking param: v to result ~r0 level=0$" + return v._up +} + +func (v V) UPP() **U { // ERROR "leaking param: v to result ~r0 level=0$" + return v._upp +} + +func (v V) UPPia() *U { // ERROR "leaking param: v to result ~r0 level=1$" + return *v._upp +} + +func (v V) UPPib() *U { // ERROR "leaking param: v to result ~r0 level=1$" + return *v.UPP() +} + +func (v V) USPa() *string { // ERROR "leaking param: v to result ~r0 level=0$" + return v._u._sp +} + +func (v V) USPb() *string { // ERROR "leaking param: v to result ~r0 level=0$" + return v.u()._sp +} + +func (v V) USPPia() *string { // ERROR "leaking param: v to result ~r0 level=1$" + return *v._u._spp +} + +func (v V) USPPib() *string { // ERROR "leaking param: v to result ~r0 level=1$" + return v._u.SPPi() +} + +func (v V) UPiSPa() *string { // ERROR "leaking param: v to result ~r0 level=1$" + return v._up._sp +} + +func (v V) UPiSPb() *string { // ERROR "leaking param: v to result ~r0 level=1$" + return v._up.SP() +} + +func (v V) UPiSPc() *string { // ERROR "leaking param: v to result ~r0 level=1$" + return v.UP()._sp +} + +func (v V) UPiSPd() *string { // ERROR "leaking param: v to result ~r0 level=1$" + return v.UP().SP() +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 +func tUPiSPa() { + s1 := "ant" + s2 := "bat" // ERROR "moved to heap: s2$" + s3 := "cat" // ERROR "moved to heap: s3$" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "&s2 escapes to heap$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" "moved to heap: ps4$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPa &ps2 does not escape$" "tUPiSPa &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "&ps4 escapes to heap$" "&s3 escapes to heap$" "tUPiSPa &U literal does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$" "&ps6 escapes to heap$" "&s5 escapes to heap$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPa &V literal does not escape$" "tUPiSPa &u3 does not escape$" + Ssink = v.UPiSPa() // Ssink = &s3 (only &s3 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 +func tUPiSPb() { + s1 := "ant" + s2 := "bat" // ERROR "moved to heap: s2$" + s3 := "cat" // ERROR "moved to heap: s3$" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "&s2 escapes to heap$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" "moved to heap: ps4$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPb &ps2 does not escape$" "tUPiSPb &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "&ps4 escapes to heap$" "&s3 escapes to heap$" "tUPiSPb &U literal does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$" "&ps6 escapes to heap$" "&s5 escapes to heap$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPb &V literal does not escape$" "tUPiSPb &u3 does not escape$" + Ssink = v.UPiSPb() // Ssink = &s3 (only &s3 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 +func tUPiSPc() { + s1 := "ant" + s2 := "bat" // ERROR "moved to heap: s2$" + s3 := "cat" // ERROR "moved to heap: s3$" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "&s2 escapes to heap$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" "moved to heap: ps4$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPc &ps2 does not escape$" "tUPiSPc &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "&ps4 escapes to heap$" "&s3 escapes to heap$" "tUPiSPc &U literal does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$" "&ps6 escapes to heap$" "&s5 escapes to heap$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPc &V literal does not escape$" "tUPiSPc &u3 does not escape$" + Ssink = v.UPiSPc() // Ssink = &s3 (only &s3 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 +func tUPiSPd() { + s1 := "ant" + s2 := "bat" // ERROR "moved to heap: s2$" + s3 := "cat" // ERROR "moved to heap: s3$" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "&s2 escapes to heap$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" "moved to heap: ps4$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPd &ps2 does not escape$" "tUPiSPd &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "&ps4 escapes to heap$" "&s3 escapes to heap$" "tUPiSPd &U literal does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$" "&ps6 escapes to heap$" "&s5 escapes to heap$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPd &V literal does not escape$" "tUPiSPd &u3 does not escape$" + Ssink = v.UPiSPd() // Ssink = &s3 (only &s3 really escapes) +} + +func (v V) UPiSPPia() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return *v._up._spp +} + +func (v V) UPiSPPib() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return v._up.SPPi() +} + +func (v V) UPiSPPic() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return *v.UP()._spp +} + +func (v V) UPiSPPid() *string { // ERROR "leaking param: v to result ~r0 level=2$" + return v.UP().SPPi() +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 +func tUPiSPPia() { + s1 := "ant" + s2 := "bat" + s3 := "cat" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "tUPiSPPia &s2 does not escape$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPPia &ps2 does not escape$" "tUPiSPPia &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "tUPiSPPia &U literal does not escape$" "tUPiSPPia &ps4 does not escape$" "tUPiSPPia &s3 does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&ps6 escapes to heap$" "&s5 escapes to heap$" "tUPiSPPia &U literal does not escape$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPPia &V literal does not escape$" "tUPiSPPia &u3 does not escape$" + Ssink = v.UPiSPPia() // Ssink = *&ps4 = &s4 (only &s4 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 +func tUPiSPPib() { + s1 := "ant" + s2 := "bat" + s3 := "cat" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "tUPiSPPib &s2 does not escape$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPPib &ps2 does not escape$" "tUPiSPPib &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "tUPiSPPib &U literal does not escape$" "tUPiSPPib &ps4 does not escape$" "tUPiSPPib &s3 does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&ps6 escapes to heap$" "&s5 escapes to heap$" "tUPiSPPib &U literal does not escape$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPPib &V literal does not escape$" "tUPiSPPib &u3 does not escape$" + Ssink = v.UPiSPPib() // Ssink = *&ps4 = &s4 (only &s4 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 +func tUPiSPPic() { + s1 := "ant" + s2 := "bat" + s3 := "cat" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "tUPiSPPic &s2 does not escape$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPPic &ps2 does not escape$" "tUPiSPPic &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "tUPiSPPic &U literal does not escape$" "tUPiSPPic &ps4 does not escape$" "tUPiSPPic &s3 does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&ps6 escapes to heap$" "&s5 escapes to heap$" "tUPiSPPic &U literal does not escape$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPPic &V literal does not escape$" "tUPiSPPic &u3 does not escape$" + Ssink = v.UPiSPPic() // Ssink = *&ps4 = &s4 (only &s4 really escapes) +} + +// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 +func tUPiSPPid() { + s1 := "ant" + s2 := "bat" + s3 := "cat" + s4 := "dog" // ERROR "moved to heap: s4$" + s5 := "emu" // ERROR "moved to heap: s5$" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "tUPiSPPid &s2 does not escape$" + ps4 := &s4 // ERROR "&s4 escapes to heap$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" "moved to heap: ps6$" + u1 := U{&s1, &ps2} // ERROR "tUPiSPPid &ps2 does not escape$" "tUPiSPPid &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "tUPiSPPid &U literal does not escape$" "tUPiSPPid &ps4 does not escape$" "tUPiSPPid &s3 does not escape$" + u3 := &U{&s5, &ps6} // ERROR "&ps6 escapes to heap$" "&s5 escapes to heap$" "tUPiSPPid &U literal does not escape$" + v := &V{u1, u2, &u3} // ERROR "tUPiSPPid &V literal does not escape$" "tUPiSPPid &u3 does not escape$" + Ssink = v.UPiSPPid() // Ssink = *&ps4 = &s4 (only &s4 really escapes) +} + +func (v V) UPPiSPPia() *string { // ERROR "leaking param: v to result ~r0 level=3$" + return *(*v._upp)._spp +} + +// This test isolates the one value that needs to escape, not because +// it distinguishes fields but because it knows that &s6 is the only +// value reachable by two indirects from v. +// The test depends on the level cap in the escape analysis tags +// being able to encode that fact. +func tUPPiSPPia() { // This test is sensitive to the level cap in function summary results. + s1 := "ant" + s2 := "bat" + s3 := "cat" + s4 := "dog" + s5 := "emu" + s6 := "fox" // ERROR "moved to heap: s6$" + ps2 := &s2 // ERROR "tUPPiSPPia &s2 does not escape$" + ps4 := &s4 // ERROR "tUPPiSPPia &s4 does not escape$" + ps6 := &s6 // ERROR "&s6 escapes to heap$" + u1 := U{&s1, &ps2} // ERROR "tUPPiSPPia &ps2 does not escape$" "tUPPiSPPia &s1 does not escape$" + u2 := &U{&s3, &ps4} // ERROR "tUPPiSPPia &U literal does not escape$" "tUPPiSPPia &ps4 does not escape$" "tUPPiSPPia &s3 does not escape$" + u3 := &U{&s5, &ps6} // ERROR "tUPPiSPPia &U literal does not escape$" "tUPPiSPPia &ps6 does not escape$" "tUPPiSPPia &s5 does not escape$" + v := &V{u1, u2, &u3} // ERROR "tUPPiSPPia &V literal does not escape$" "tUPPiSPPia &u3 does not escape$" + Ssink = v.UPPiSPPia() // Ssink = *&ps6 = &s6 (only &s6 really escapes) +} diff --git a/test/escape_struct_return.go b/test/escape_struct_return.go new file mode 100644 index 0000000000..b423ebd92a --- /dev/null +++ b/test/escape_struct_return.go @@ -0,0 +1,74 @@ +// errorcheck -0 -m -l + +// 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. + +// Test escape analysis for function parameters. + +package foo + +var Ssink *string + +type U struct { + _sp *string + _spp **string +} + +func A(sp *string, spp **string) U { // ERROR "leaking param: sp to result ~r2 level=0$" "leaking param: spp to result ~r2 level=0$" + return U{sp, spp} +} + +func B(spp **string) U { // ERROR "leaking param: spp to result ~r1 level=0$" "leaking param: spp to result ~r1 level=1$" + return U{*spp, spp} +} + +func tA1() { + s := "cat" + sp := &s // ERROR "tA1 &s does not escape$" + spp := &sp // ERROR "tA1 &sp does not escape$" + u := A(sp, spp) + _ = u + println(s) +} + +func tA2() { + s := "cat" + sp := &s // ERROR "tA2 &s does not escape$" + spp := &sp // ERROR "tA2 &sp does not escape$" + u := A(sp, spp) + println(*u._sp) +} + +func tA3() { + s := "cat" + sp := &s // ERROR "tA3 &s does not escape$" + spp := &sp // ERROR "tA3 &sp does not escape$" + u := A(sp, spp) + println(**u._spp) +} + +func tB1() { + s := "cat" + sp := &s // ERROR "tB1 &s does not escape$" + spp := &sp // ERROR "tB1 &sp does not escape$" + u := B(spp) + _ = u + println(s) +} + +func tB2() { + s := "cat" + sp := &s // ERROR "tB2 &s does not escape$" + spp := &sp // ERROR "tB2 &sp does not escape$" + u := B(spp) + println(*u._sp) +} + +func tB3() { + s := "cat" + sp := &s // ERROR "tB3 &s does not escape$" + spp := &sp // ERROR "tB3 &sp does not escape$" + u := B(spp) + println(**u._spp) +} diff --git a/test/fixedbugs/issue10353.go b/test/fixedbugs/issue10353.go index 4886337db9..87771d400d 100644 --- a/test/fixedbugs/issue10353.go +++ b/test/fixedbugs/issue10353.go @@ -45,5 +45,5 @@ func growstack(x int) { if x == 0 { return } - growstack(x-1) + growstack(x - 1) } |