diff options
| -rw-r--r-- | src/cmd/compile/internal/base/debug.go | 1 | ||||
| -rw-r--r-- | src/cmd/compile/internal/base/flag.go | 3 | ||||
| -rw-r--r-- | src/cmd/compile/internal/gc/gsubr.go | 191 | ||||
| -rw-r--r-- | src/cmd/compile/internal/gc/main.go | 23 | ||||
| -rw-r--r-- | src/cmd/compile/internal/gc/pgen.go | 7 | ||||
| -rw-r--r-- | src/cmd/compile/internal/gc/racewalk.go | 2 | ||||
| -rw-r--r-- | src/cmd/compile/internal/gc/ssa.go | 49 | ||||
| -rw-r--r-- | src/cmd/compile/internal/types/sym.go | 17 | ||||
| -rw-r--r-- | src/cmd/internal/obj/link.go | 6 | ||||
| -rw-r--r-- | src/cmd/internal/obj/plist.go | 6 | ||||
| -rw-r--r-- | src/cmd/internal/obj/textflag.go | 3 | ||||
| -rw-r--r-- | src/cmd/internal/obj/x86/obj6.go | 4 | ||||
| -rw-r--r-- | src/cmd/link/internal/ld/main.go | 12 | ||||
| -rw-r--r-- | src/cmd/link/internal/ld/symtab.go | 37 | ||||
| -rw-r--r-- | src/runtime/textflag.h | 2 | ||||
| -rw-r--r-- | test/nosplit.go | 9 |
16 files changed, 328 insertions, 44 deletions
diff --git a/src/cmd/compile/internal/base/debug.go b/src/cmd/compile/internal/base/debug.go index 45a552a4d9..3acdcea846 100644 --- a/src/cmd/compile/internal/base/debug.go +++ b/src/cmd/compile/internal/base/debug.go @@ -51,6 +51,7 @@ type DebugFlags struct { TypeAssert int `help:"print information about type assertion inlining"` TypecheckInl int `help:"eager typechecking of inline function bodies"` WB int `help:"print information about write barriers"` + ABIWrap int `help:"print information about ABI wrapper generation"` any bool // set when any of the values have been set } diff --git a/src/cmd/compile/internal/base/flag.go b/src/cmd/compile/internal/base/flag.go index aadc70f496..ce87ff730e 100644 --- a/src/cmd/compile/internal/base/flag.go +++ b/src/cmd/compile/internal/base/flag.go @@ -81,6 +81,8 @@ type CmdFlags struct { CompilingRuntime bool "flag:\"+\" help:\"compiling runtime\"" // Longer names + ABIWrap bool "help:\"enable generation of ABI wrappers\"" + ABIWrapLimit int "help:\"emit at most N ABI wrappers (for debugging)\"" AsmHdr string "help:\"write assembly header to `file`\"" Bench string "help:\"append benchmark times to `file`\"" BlockProfile string "help:\"write block profile to `file`\"" @@ -140,6 +142,7 @@ func ParseFlags() { Flag.LowerP = &Ctxt.Pkgpath Flag.LowerV = &Ctxt.Debugvlog + Flag.ABIWrap = objabi.Regabi_enabled != 0 Flag.Dwarf = objabi.GOARCH != "wasm" Flag.DwarfBASEntries = &Ctxt.UseBASEntries Flag.DwarfLocationLists = &Ctxt.Flag_locationlists diff --git a/src/cmd/compile/internal/gc/gsubr.go b/src/cmd/compile/internal/gc/gsubr.go index ddb431d5ab..f3ef14c99b 100644 --- a/src/cmd/compile/internal/gc/gsubr.go +++ b/src/cmd/compile/internal/gc/gsubr.go @@ -34,9 +34,12 @@ import ( "cmd/compile/internal/base" "cmd/compile/internal/ir" "cmd/compile/internal/ssa" + "cmd/compile/internal/types" "cmd/internal/obj" "cmd/internal/objabi" "cmd/internal/src" + "fmt" + "os" ) var sharedProgArray = new([10000]obj.Prog) // *T instead of T to work around issue 19839 @@ -187,32 +190,154 @@ func (pp *Progs) settext(fn *ir.Func) { ptxt.From.Sym = fn.LSym } +// makeABIWrapper creates a new function that wraps a cross-ABI call +// to "f". The wrapper is marked as an ABIWRAPPER. +func makeABIWrapper(f *ir.Func, wrapperABI obj.ABI) { + + // Q: is this needed? + savepos := base.Pos + savedclcontext := dclcontext + savedcurfn := Curfn + + base.Pos = autogeneratedPos + dclcontext = ir.PEXTERN + + // At the moment we don't support wrapping a method, we'd need machinery + // below to handle the receiver. Panic if we see this scenario. + ft := f.Nname.Ntype.Type() + if ft.NumRecvs() != 0 { + panic("makeABIWrapper support for wrapping methods not implemented") + } + + // Manufacture a new func type to use for the wrapper. + var noReceiver *ir.Field + tfn := ir.NewFuncType(base.Pos, + noReceiver, + structargs(ft.Params(), true), + structargs(ft.Results(), false)) + + // Reuse f's types.Sym to create a new ODCLFUNC/function. + fn := dclfunc(f.Nname.Sym(), tfn) + fn.SetDupok(true) + fn.SetWrapper(true) // ignore frame for panic+recover matching + + // Select LSYM now. + asym := base.Ctxt.LookupABI(f.LSym.Name, wrapperABI) + asym.Type = objabi.STEXT + if fn.LSym != nil { + panic("unexpected") + } + fn.LSym = asym + + // ABI0-to-ABIInternal wrappers will be mainly loading params from + // stack into registers (and/or storing stack locations back to + // registers after the wrapped call); in most cases they won't + // need to allocate stack space, so it should be OK to mark them + // as NOSPLIT in these cases. In addition, my assumption is that + // functions written in assembly are NOSPLIT in most (but not all) + // cases. In the case of an ABIInternal target that has too many + // parameters to fit into registers, the wrapper would need to + // allocate stack space, but this seems like an unlikely scenario. + // Hence: mark these wrappers NOSPLIT. + // + // ABIInternal-to-ABI0 wrappers on the other hand will be taking + // things in registers and pushing them onto the stack prior to + // the ABI0 call, meaning that they will always need to allocate + // stack space. If the compiler marks them as NOSPLIT this seems + // as though it could lead to situations where the the linker's + // nosplit-overflow analysis would trigger a link failure. On the + // other hand if they not tagged NOSPLIT then this could cause + // problems when building the runtime (since there may be calls to + // asm routine in cases where it's not safe to grow the stack). In + // most cases the wrapper would be (in effect) inlined, but are + // there (perhaps) indirect calls from the runtime that could run + // into trouble here. + // FIXME: at the moment all.bash does not pass when I leave out + // NOSPLIT for these wrappers, so all are currently tagged with NOSPLIT. + setupTextLSym(fn, obj.NOSPLIT|obj.ABIWRAPPER) + + // Generate call. Use tail call if no params and no returns, + // but a regular call otherwise. + // + // Note: ideally we would be using a tail call in cases where + // there are params but no returns for ABI0->ABIInternal wrappers, + // provided that all params fit into registers (e.g. we don't have + // to allocate any stack space). Doing this will require some + // extra work in typecheck/walk/ssa, might want to add a new node + // OTAILCALL or something to this effect. + var call ir.Node + if tfn.Type().NumResults() == 0 && tfn.Type().NumParams() == 0 && tfn.Type().NumRecvs() == 0 { + call = nodSym(ir.ORETJMP, nil, f.Nname.Sym()) + } else { + call = ir.Nod(ir.OCALL, f.Nname, nil) + call.PtrList().Set(paramNnames(tfn.Type())) + call.SetIsDDD(tfn.Type().IsVariadic()) + if tfn.Type().NumResults() > 0 { + n := ir.Nod(ir.ORETURN, nil, nil) + n.PtrList().Set1(call) + call = n + } + } + fn.PtrBody().Append(call) + + funcbody() + if base.Debug.DclStack != 0 { + testdclstack() + } + + typecheckFunc(fn) + Curfn = fn + typecheckslice(fn.Body().Slice(), ctxStmt) + + escapeFuncs([]*ir.Func{fn}, false) + + Target.Decls = append(Target.Decls, fn) + + // Restore previous context. + base.Pos = savepos + dclcontext = savedclcontext + Curfn = savedcurfn +} + // initLSym defines f's obj.LSym and initializes it based on the // properties of f. This includes setting the symbol flags and ABI and // creating and initializing related DWARF symbols. // // initLSym must be called exactly once per function and must be // called for both functions with bodies and functions without bodies. +// For body-less functions, we only create the LSym; for functions +// with bodies call a helper to setup up / populate the LSym. func initLSym(f *ir.Func, hasBody bool) { + // FIXME: for new-style ABI wrappers, we set up the lsym at the + // point the wrapper is created. + if f.LSym != nil && base.Flag.ABIWrap { + return + } + selectLSym(f, hasBody) + if hasBody { + setupTextLSym(f, 0) + } +} + +// selectLSym sets up the LSym for a given function, and +// makes calls to helpers to create ABI wrappers if needed. +func selectLSym(f *ir.Func, hasBody bool) { if f.LSym != nil { base.Fatalf("Func.initLSym called twice") } if nam := f.Nname; !ir.IsBlank(nam) { - f.LSym = nam.Sym().Linksym() - if f.Pragma&ir.Systemstack != 0 { - f.LSym.Set(obj.AttrCFunc, true) - } - var aliasABI obj.ABI - needABIAlias := false - defABI, hasDefABI := symabiDefs[f.LSym.Name] + var wrapperABI obj.ABI + needABIWrapper := false + defABI, hasDefABI := symabiDefs[nam.Sym().LinksymName()] if hasDefABI && defABI == obj.ABI0 { // Symbol is defined as ABI0. Create an // Internal -> ABI0 wrapper. - f.LSym.SetABI(obj.ABI0) - needABIAlias, aliasABI = true, obj.ABIInternal + f.LSym = nam.Sym().LinksymABI0() + needABIWrapper, wrapperABI = true, obj.ABIInternal } else { + f.LSym = nam.Sym().Linksym() // No ABI override. Check that the symbol is // using the expected ABI. want := obj.ABIInternal @@ -220,6 +345,9 @@ func initLSym(f *ir.Func, hasBody bool) { base.Fatalf("function symbol %s has the wrong ABI %v, expected %v", f.LSym.Name, f.LSym.ABI(), want) } } + if f.Pragma&ir.Systemstack != 0 { + f.LSym.Set(obj.AttrCFunc, true) + } isLinknameExported := nam.Sym().Linkname != "" && (hasBody || hasDefABI) if abi, ok := symabiRefs[f.LSym.Name]; (ok && abi == obj.ABI0) || isLinknameExported { @@ -235,32 +363,39 @@ func initLSym(f *ir.Func, hasBody bool) { // using linkname and we don't want to create // duplicate ABI wrappers. if f.LSym.ABI() != obj.ABI0 { - needABIAlias, aliasABI = true, obj.ABI0 + needABIWrapper, wrapperABI = true, obj.ABI0 } } - if needABIAlias { - // These LSyms have the same name as the - // native function, so we create them directly - // rather than looking them up. The uniqueness - // of f.lsym ensures uniqueness of asym. - asym := &obj.LSym{ - Name: f.LSym.Name, - Type: objabi.SABIALIAS, - R: []obj.Reloc{{Sym: f.LSym}}, // 0 size, so "informational" + if needABIWrapper { + if !useABIWrapGen(f) { + // Fallback: use alias instead. FIXME. + + // These LSyms have the same name as the + // native function, so we create them directly + // rather than looking them up. The uniqueness + // of f.lsym ensures uniqueness of asym. + asym := &obj.LSym{ + Name: f.LSym.Name, + Type: objabi.SABIALIAS, + R: []obj.Reloc{{Sym: f.LSym}}, // 0 size, so "informational" + } + asym.SetABI(wrapperABI) + asym.Set(obj.AttrDuplicateOK, true) + base.Ctxt.ABIAliases = append(base.Ctxt.ABIAliases, asym) + } else { + if base.Debug.ABIWrap != 0 { + fmt.Fprintf(os.Stderr, "=-= %v to %v wrapper for %s.%s\n", + wrapperABI, 1-wrapperABI, types.LocalPkg.Path, f.LSym.Name) + } + makeABIWrapper(f, wrapperABI) } - asym.SetABI(aliasABI) - asym.Set(obj.AttrDuplicateOK, true) - base.Ctxt.ABIAliases = append(base.Ctxt.ABIAliases, asym) } } +} - if !hasBody { - // For body-less functions, we only create the LSym. - return - } - - var flag int +// setupTextLsym initializes the LSym for a with-body text symbol. +func setupTextLSym(f *ir.Func, flag int) { if f.Dupok() { flag |= obj.DUPOK } diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go index 7f7cd63cdf..de2b3db36a 100644 --- a/src/cmd/compile/internal/gc/main.go +++ b/src/cmd/compile/internal/gc/main.go @@ -1144,3 +1144,26 @@ func initializeTypesPackage() { initUniverse() } + +// useNewABIWrapGen returns TRUE if the compiler should generate an +// ABI wrapper for the function 'f'. +func useABIWrapGen(f *ir.Func) bool { + if !base.Flag.ABIWrap { + return false + } + + // Support limit option for bisecting. + if base.Flag.ABIWrapLimit == 1 { + return false + } + if base.Flag.ABIWrapLimit < 1 { + return true + } + base.Flag.ABIWrapLimit-- + if base.Debug.ABIWrap != 0 && base.Flag.ABIWrapLimit == 1 { + fmt.Fprintf(os.Stderr, "=-= limit reached after new wrapper for %s\n", + f.LSym.Name) + } + + return true +} diff --git a/src/cmd/compile/internal/gc/pgen.go b/src/cmd/compile/internal/gc/pgen.go index 5b5288c389..dae9d79147 100644 --- a/src/cmd/compile/internal/gc/pgen.go +++ b/src/cmd/compile/internal/gc/pgen.go @@ -32,7 +32,6 @@ func emitptrargsmap(fn *ir.Func) { return } lsym := base.Ctxt.Lookup(fn.LSym.Name + ".args_stackmap") - nptr := int(fn.Type().ArgWidth() / int64(Widthptr)) bv := bvalloc(int32(nptr) * 2) nbitmap := 1 @@ -399,7 +398,11 @@ func debuginfo(fnsym *obj.LSym, infosym *obj.LSym, curfn interface{}) ([]dwarf.S fn := curfn.(*ir.Func) if fn.Nname != nil { - if expect := fn.Sym().Linksym(); fnsym != expect { + expect := fn.Sym().Linksym() + if fnsym.ABI() == obj.ABI0 { + expect = fn.Sym().LinksymABI0() + } + if fnsym != expect { base.Fatalf("unexpected fnsym: %v != %v", fnsym, expect) } } diff --git a/src/cmd/compile/internal/gc/racewalk.go b/src/cmd/compile/internal/gc/racewalk.go index 472deb16e3..61a65368af 100644 --- a/src/cmd/compile/internal/gc/racewalk.go +++ b/src/cmd/compile/internal/gc/racewalk.go @@ -61,7 +61,7 @@ func ispkgin(pkgs []string) bool { } func instrument(fn *ir.Func) { - if fn.Pragma&ir.Norace != 0 { + if fn.Pragma&ir.Norace != 0 || (fn.Sym().Linksym() != nil && fn.Sym().Linksym().ABIWrapper()) { return } diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go index a5340e7f11..b4cf8b6dc7 100644 --- a/src/cmd/compile/internal/gc/ssa.go +++ b/src/cmd/compile/internal/gc/ssa.go @@ -1421,7 +1421,7 @@ func (s *state) stmt(n ir.Node) { case ir.ORETJMP: b := s.exit() b.Kind = ssa.BlockRetJmp // override BlockRet - b.Aux = n.Sym().Linksym() + b.Aux = callTargetLSym(n.Sym(), s.curfn.LSym) case ir.OCONTINUE, ir.OBREAK: var to *ssa.Block @@ -4826,11 +4826,11 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val } case sym != nil: if testLateExpansion { - aux := ssa.StaticAuxCall(sym.Linksym(), ACArgs, ACResults) + aux := ssa.StaticAuxCall(callTargetLSym(sym, s.curfn.LSym), ACArgs, ACResults) call = s.newValue0A(ssa.OpStaticLECall, aux.LateExpansionResultType(), aux) call.AddArgs(callArgs...) } else { - call = s.newValue1A(ssa.OpStaticCall, types.TypeMem, ssa.StaticAuxCall(sym.Linksym(), ACArgs, ACResults), s.mem()) + call = s.newValue1A(ssa.OpStaticCall, types.TypeMem, ssa.StaticAuxCall(callTargetLSym(sym, s.curfn.LSym), ACArgs, ACResults), s.mem()) } default: s.Fatalf("bad call type %v %v", n.Op(), n) @@ -7291,3 +7291,46 @@ func clobberBase(n ir.Node) ir.Node { } return n } + +// callTargetLSym determines the correct LSym for 'callee' when called +// from function 'caller'. There are a couple of different scenarios +// to contend with here: +// +// 1. if 'caller' is an ABI wrapper, then we always want to use the +// LSym from the Func for the callee. +// +// 2. if 'caller' is not an ABI wrapper, then we looked at the callee +// to see if it corresponds to a "known" ABI0 symbol (e.g. assembly +// routine defined in the current package); if so, we want the call to +// directly target the ABI0 symbol (effectively bypassing the +// ABIInternal->ABI0 wrapper for 'callee'). +// +// 3. in all other cases, want the regular ABIInternal linksym +// +func callTargetLSym(callee *types.Sym, callerLSym *obj.LSym) *obj.LSym { + lsym := callee.Linksym() + if !base.Flag.ABIWrap { + return lsym + } + if ir.AsNode(callee.Def) == nil { + return lsym + } + ndclfunc := ir.AsNode(callee.Def).Name().Defn + if ndclfunc == nil { + return lsym + } + // check for case 1 above + if callerLSym.ABIWrapper() { + if nlsym := ndclfunc.Func().LSym; nlsym != nil { + lsym = nlsym + } + } else { + // check for case 2 above + nam := ndclfunc.Func().Nname + defABI, hasDefABI := symabiDefs[nam.Sym().LinksymName()] + if hasDefABI && defABI == obj.ABI0 { + lsym = nam.Sym().LinksymABI0() + } + } + return lsym +} diff --git a/src/cmd/compile/internal/types/sym.go b/src/cmd/compile/internal/types/sym.go index 19f06fcf5b..c512e3a003 100644 --- a/src/cmd/compile/internal/types/sym.go +++ b/src/cmd/compile/internal/types/sym.go @@ -93,6 +93,23 @@ func (sym *Sym) Linksym() *obj.LSym { return base.Ctxt.LookupInit(sym.LinksymName(), initPkg) } +// LinksymABI0 looks up or creates an ABI0 linker symbol for "sym", +// in cases where we want to specifically select the ABI0 version of +// a symbol (typically used only for ABI wrappers). +func (sym *Sym) LinksymABI0() *obj.LSym { + if sym == nil { + return nil + } + initPkg := func(r *obj.LSym) { + if sym.Linkname != "" { + r.Pkg = "_" + } else { + r.Pkg = sym.Pkg.Prefix + } + } + return base.Ctxt.LookupABIInit(sym.LinksymName(), obj.ABI0, initPkg) +} + // Less reports whether symbol a is ordered before symbol b. // // Symbols are ordered exported before non-exported, then by name, and diff --git a/src/cmd/internal/obj/link.go b/src/cmd/internal/obj/link.go index 7b5c990a5d..977c5c3303 100644 --- a/src/cmd/internal/obj/link.go +++ b/src/cmd/internal/obj/link.go @@ -635,6 +635,10 @@ const ( // ContentAddressable indicates this is a content-addressable symbol. AttrContentAddressable + // ABI wrapper is set for compiler-generated text symbols that + // convert between ABI0 and ABIInternal calling conventions. + AttrABIWrapper + // attrABIBase is the value at which the ABI is encoded in // Attribute. This must be last; all bits after this are // assumed to be an ABI value. @@ -660,6 +664,7 @@ func (a Attribute) TopFrame() bool { return a&AttrTopFrame != 0 } func (a Attribute) Indexed() bool { return a&AttrIndexed != 0 } func (a Attribute) UsedInIface() bool { return a&AttrUsedInIface != 0 } func (a Attribute) ContentAddressable() bool { return a&AttrContentAddressable != 0 } +func (a Attribute) ABIWrapper() bool { return a&AttrABIWrapper != 0 } func (a *Attribute) Set(flag Attribute, value bool) { if value { @@ -695,6 +700,7 @@ var textAttrStrings = [...]struct { {bit: AttrTopFrame, s: "TOPFRAME"}, {bit: AttrIndexed, s: ""}, {bit: AttrContentAddressable, s: ""}, + {bit: AttrABIWrapper, s: "ABIWRAPPER"}, } // TextAttrString formats a for printing in as part of a TEXT prog. diff --git a/src/cmd/internal/obj/plist.go b/src/cmd/internal/obj/plist.go index 2b096996f7..679ce7eb8f 100644 --- a/src/cmd/internal/obj/plist.go +++ b/src/cmd/internal/obj/plist.go @@ -80,6 +80,11 @@ func Flushplist(ctxt *Link, plist *Plist, newprog ProgAlloc, myimportpath string if !strings.HasPrefix(s.Name, "\"\".") { continue } + if s.ABIWrapper() { + // Don't create an args_stackmap symbol reference for an ABI + // wrapper function + continue + } found := false for p := s.Func().Text; p != nil; p = p.Link { if p.As == AFUNCDATA && p.From.Type == TYPE_CONST && p.From.Offset == objabi.FUNCDATA_ArgsPointerMaps { @@ -134,6 +139,7 @@ func (ctxt *Link) InitTextSym(s *LSym, flag int) { s.Set(AttrNoSplit, flag&NOSPLIT != 0) s.Set(AttrReflectMethod, flag&REFLECTMETHOD != 0) s.Set(AttrWrapper, flag&WRAPPER != 0) + s.Set(AttrABIWrapper, flag&ABIWRAPPER != 0) s.Set(AttrNeedCtxt, flag&NEEDCTXT != 0) s.Set(AttrNoFrame, flag&NOFRAME != 0) s.Set(AttrTopFrame, flag&TOPFRAME != 0) diff --git a/src/cmd/internal/obj/textflag.go b/src/cmd/internal/obj/textflag.go index d2cec734b1..fcc4014aa2 100644 --- a/src/cmd/internal/obj/textflag.go +++ b/src/cmd/internal/obj/textflag.go @@ -51,4 +51,7 @@ const ( // Function is the top of the call stack. Call stack unwinders should stop // at this function. TOPFRAME = 2048 + + // Function is an ABI wrapper. + ABIWRAPPER = 4096 ) diff --git a/src/cmd/internal/obj/x86/obj6.go b/src/cmd/internal/obj/x86/obj6.go index 184fb4308b..839aeb8fe3 100644 --- a/src/cmd/internal/obj/x86/obj6.go +++ b/src/cmd/internal/obj/x86/obj6.go @@ -637,7 +637,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) { } } - if !p.From.Sym.NoSplit() || p.From.Sym.Wrapper() { + if !p.From.Sym.NoSplit() || (p.From.Sym.Wrapper() && !p.From.Sym.ABIWrapper()) { p = obj.Appendp(p, newprog) p = load_g_cx(ctxt, p, newprog) // load g into CX } @@ -690,7 +690,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) { p.To.Reg = REG_BP } - if cursym.Func().Text.From.Sym.Wrapper() { + if cursym.Func().Text.From.Sym.Wrapper() && !cursym.Func().Text.From.Sym.ABIWrapper() { // if g._panic != nil && g._panic.argp == FP { // g._panic.argp = bottom-of-frame // } diff --git a/src/cmd/link/internal/ld/main.go b/src/cmd/link/internal/ld/main.go index 5c8293810f..1420030eec 100644 --- a/src/cmd/link/internal/ld/main.go +++ b/src/cmd/link/internal/ld/main.go @@ -92,11 +92,10 @@ var ( FlagRound = flag.Int("R", -1, "set address rounding `quantum`") FlagTextAddr = flag.Int64("T", -1, "set text segment `address`") flagEntrySymbol = flag.String("E", "", "set `entry` symbol name") - - cpuprofile = flag.String("cpuprofile", "", "write cpu profile to `file`") - memprofile = flag.String("memprofile", "", "write memory profile to `file`") - memprofilerate = flag.Int64("memprofilerate", 0, "set runtime.MemProfileRate to `rate`") - + cpuprofile = flag.String("cpuprofile", "", "write cpu profile to `file`") + memprofile = flag.String("memprofile", "", "write memory profile to `file`") + memprofilerate = flag.Int64("memprofilerate", 0, "set runtime.MemProfileRate to `rate`") + flagAbiWrap = false benchmarkFlag = flag.String("benchmark", "", "set to 'mem' or 'cpu' to enable phase benchmarking") benchmarkFileFlag = flag.String("benchmarkprofile", "", "emit phase profiles to `base`_phase.{cpu,mem}prof") ) @@ -135,6 +134,9 @@ func Main(arch *sys.Arch, theArch Arch) { objabi.Flagfn1("X", "add string value `definition` of the form importpath.name=value", func(s string) { addstrdata1(ctxt, s) }) objabi.Flagcount("v", "print link trace", &ctxt.Debugvlog) objabi.Flagfn1("importcfg", "read import configuration from `file`", ctxt.readImportCfg) + if objabi.Regabi_enabled != 0 { + flag.BoolVar(&flagAbiWrap, "abiwrap", true, "support ABI wrapper functions") + } objabi.Flagparse(usage) diff --git a/src/cmd/link/internal/ld/symtab.go b/src/cmd/link/internal/ld/symtab.go index c98e4de03f..3b709baf75 100644 --- a/src/cmd/link/internal/ld/symtab.go +++ b/src/cmd/link/internal/ld/symtab.go @@ -102,6 +102,41 @@ func putelfsym(ctxt *Link, x loader.Sym, typ elf.SymType, curbind elf.SymBind) { elfshnum = xosect.Elfsect.(*ElfShdr).shnum } + sname := ldr.SymExtname(x) + + // For functions with ABI wrappers, we have to make sure that we + // don't wind up with two elf symbol table entries with the same + // name (since this will generated an error from the external + // linker). In the CgoExportStatic case, we want the ABI0 symbol + // to have the primary symbol table entry (since it's going to be + // called from C), so we rename the ABIInternal symbol. In all + // other cases, we rename the ABI0 symbol, since we want + // cross-load-module calls to target ABIInternal. + // + // TODO: generalize this for non-ELF (put the rename code in the + // loader, and store the rename result in SymExtname). + // + // TODO: avoid the ldr.Lookup calls below by instead using an aux + // sym or marker relocation to associate the wrapper with the + // wrapped function. + // + if flagAbiWrap { + if !ldr.IsExternal(x) && ldr.SymType(x) == sym.STEXT { + // First case + if ldr.SymVersion(x) == sym.SymVerABIInternal { + if s2 := ldr.Lookup(sname, sym.SymVerABI0); s2 != 0 && ldr.AttrCgoExportStatic(s2) && ldr.SymType(s2) == sym.STEXT { + sname = sname + ".abiinternal" + } + } + // Second case + if ldr.SymVersion(x) == sym.SymVerABI0 && !ldr.AttrCgoExportStatic(x) { + if s2 := ldr.Lookup(sname, sym.SymVerABIInternal); s2 != 0 && ldr.SymType(s2) == sym.STEXT { + sname = sname + ".abi0" + } + } + } + } + // One pass for each binding: elf.STB_LOCAL, elf.STB_GLOBAL, // maybe one day elf.STB_WEAK. bind := elf.STB_GLOBAL @@ -140,8 +175,6 @@ func putelfsym(ctxt *Link, x loader.Sym, typ elf.SymType, curbind elf.SymBind) { other |= 3 << 5 } - sname := ldr.SymExtname(x) - // When dynamically linking, we create Symbols by reading the names from // the symbol tables of the shared libraries and so the names need to // match exactly. Tools like DTrace will have to wait for now. diff --git a/src/runtime/textflag.h b/src/runtime/textflag.h index daca36d948..e727208cd0 100644 --- a/src/runtime/textflag.h +++ b/src/runtime/textflag.h @@ -35,3 +35,5 @@ // Function is the top of the call stack. Call stack unwinders should stop // at this function. #define TOPFRAME 2048 +// Function is an ABI wrapper. +#define ABIWRAPPER 4096 diff --git a/test/nosplit.go b/test/nosplit.go index faa7b8c2d8..8a3fa9bf35 100644 --- a/test/nosplit.go +++ b/test/nosplit.go @@ -353,7 +353,14 @@ TestCases: log.Fatal(err) } - cmd := exec.Command("go", "build") + // Turn off ABI0 wrapper generation for now. The problem here is + // that in these test cases main.main is an assembly routine, + // thus calls to it will have to go through an ABI wrapper. The + // ABI wrapper will consume some stack space, which throws off + // the numbers. + workaround := "-gcflags=-abiwrap=0" + + cmd := exec.Command("go", "build", workaround) cmd.Dir = dir output, err := cmd.CombinedOutput() if err == nil { |