cmd/link: replace SHIDDEN bit in SymKind with a bit of Attribute

Change-Id: I02dab81393cc9339895f0076df41a652aded5b60
Reviewed-on: https://go-review.googlesource.com/42025
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/cmd/link/internal/arm64/asm.go b/src/cmd/link/internal/arm64/asm.go
index 92a87f99f7dddc2a9fea049941d2e36a50f34dc9..79e6abceba742a4e1c4444f8c774f91769543b7c 100644 (file)
--- a/src/cmd/link/internal/arm64/asm.go
+++ b/src/cmd/link/internal/arm64/asm.go
@@ -250,7 +250,7 @@ func archreloc(ctxt *ld.Link, r *ld.Reloc, s *ld.Symbol, val *int64) int {
                        // (https://sourceware.org/bugzilla/show_bug.cgi?id=18270). So
                        // we convert the adrp; ld64 + R_ARM64_GOTPCREL into adrp;
                        // add + R_ADDRARM64.
-                       if !(r.Sym.Version != 0 || (r.Sym.Type&ld.SHIDDEN != 0) || r.Sym.Attr.Local()) && r.Sym.Type == ld.STEXT && ctxt.DynlinkingGo() {
+                       if !(r.Sym.Version != 0 || r.Sym.Attr.VisibilityHidden() || r.Sym.Attr.Local()) && r.Sym.Type == ld.STEXT && ctxt.DynlinkingGo() {
                                if o2&0xffc00000 != 0xf9400000 {
                                        ld.Errorf(s, "R_ARM64_GOTPCREL against unexpected instruction %x", o2)
                                }

diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go
index 8aa6cde60376a5aa3a6af60bc66e0cc8ec6c9874..8951b581d815670ac94623f5913505ca0df93bd3 100644 (file)
--- a/src/cmd/link/internal/ld/data.go
+++ b/src/cmd/link/internal/ld/data.go
@@ -386,7 +386,7 @@ func relocsym(ctxt *Link, s *Symbol) {
                        continue
                }
 
-               if r.Sym != nil && (r.Sym.Type&(SMASK|SHIDDEN) == 0 || r.Sym.Type&SMASK == SXREF) {
+               if r.Sym != nil && ((r.Sym.Type == 0 && !r.Sym.Attr.VisibilityHidden()) || r.Sym.Type&SMASK == SXREF) {
                        // When putting the runtime but not main into a shared library
                        // these symbols are undefined and that's OK.
                        if Buildmode == BuildmodeShared {

diff --git a/src/cmd/link/internal/ld/ldelf.go b/src/cmd/link/internal/ld/ldelf.go
index d4f9fc44d7493a0f8f75a2f427eb5a6e88a88e55..2b4fd66cf8e21a1144fc47e404c9b7261f75a69c 100644 (file)
--- a/src/cmd/link/internal/ld/ldelf.go
+++ b/src/cmd/link/internal/ld/ldelf.go
@@ -1060,8 +1060,7 @@ func readelfsym(ctxt *Link, elfobj *ElfObj, i int, sym *ElfSym, needSym int, loc
                                // set dupok generally. See http://codereview.appspot.com/5823055/
                                // comment #5 for details.
                                if s != nil && sym.other == 2 {
-                                       s.Type |= SHIDDEN
-                                       s.Attr |= AttrDuplicateOK
+                                       s.Attr |= AttrDuplicateOK | AttrVisibilityHidden
                                }
                        }
 
@@ -1077,7 +1076,7 @@ func readelfsym(ctxt *Link, elfobj *ElfObj, i int, sym *ElfSym, needSym int, loc
                                // so put it in the hash table.
                                if needSym != 0 {
                                        s = ctxt.Syms.Lookup(sym.name, localSymVersion)
-                                       s.Type |= SHIDDEN
+                                       s.Attr |= AttrVisibilityHidden
                                }
 
                                break
@@ -1089,14 +1088,14 @@ func readelfsym(ctxt *Link, elfobj *ElfObj, i int, sym *ElfSym, needSym int, loc
                                // don't bother to add them into the hash table
                                s = ctxt.Syms.newsym(sym.name, localSymVersion)
 
-                               s.Type |= SHIDDEN
+                               s.Attr |= AttrVisibilityHidden
                        }
 
                case ElfSymBindWeak:
                        if needSym != 0 {
                                s = ctxt.Syms.Lookup(sym.name, 0)
                                if sym.other == 2 {
-                                       s.Type |= SHIDDEN
+                                       s.Attr |= AttrVisibilityHidden
                                }
                        }
 

diff --git a/src/cmd/link/internal/ld/link.go b/src/cmd/link/internal/ld/link.go
index 089b4d3d3c1c436b1268638ade43d87034e69b60..bdb5a1bd512557f5ebea2d8a28a85e0cefa4b3b4 100644 (file)
--- a/src/cmd/link/internal/ld/link.go
+++ b/src/cmd/link/internal/ld/link.go
@@ -135,6 +135,11 @@ const (
        // AttrMakeTypelink Amarks types that should be added to the typelink
        // table. See typelinks.go:typelinks().
        AttrMakeTypelink
+       // AttrVisibilityHidden symbols are ELF symbols with
+       // visibility set to STV_HIDDEN. They become local symbols in
+       // the final executable. Only relevant when internally linking
+       // on an ELF platform.
+       AttrVisibilityHidden
 )
 
 func (a Attribute) DuplicateOK() bool      { return a&AttrDuplicateOK != 0 }
@@ -150,6 +155,7 @@ func (a Attribute) OnList() bool           { return a&AttrOnList != 0 }
 func (a Attribute) Local() bool            { return a&AttrLocal != 0 }
 func (a Attribute) ReflectMethod() bool    { return a&AttrReflectMethod != 0 }
 func (a Attribute) MakeTypelink() bool     { return a&AttrMakeTypelink != 0 }
+func (a Attribute) VisibilityHidden() bool { return a&AttrVisibilityHidden != 0 }
 
 func (a Attribute) CgoExport() bool {
        return a.CgoExportDynamic() || a.CgoExportStatic()

diff --git a/src/cmd/link/internal/ld/pe.go b/src/cmd/link/internal/ld/pe.go
index 2c28ceb0c60de7221d1ff8f5fe949f513f7bedf8..ff1ec4ad93d8e82073018d9e32f1b3c39f1ab725 100644 (file)
--- a/src/cmd/link/internal/ld/pe.go
+++ b/src/cmd/link/internal/ld/pe.go
@@ -1041,7 +1041,9 @@ func writePESymTableRecords(ctxt *Link) int {
                        typ = 0x0308 // "array of structs"
                }
                class := IMAGE_SYM_CLASS_EXTERNAL
-               if s.Version != 0 || (s.Type&SHIDDEN != 0) || s.Attr.Local() {
+               // TODO(mwudson): I think s.Attr.VisibilityHidden()
+               // can only ever be true for an ELF link.
+               if s.Version != 0 || s.Attr.VisibilityHidden() || s.Attr.Local() {
                        class = IMAGE_SYM_CLASS_STATIC
                }
                writeOneSymbol(s, value, sect, typ, uint8(class))

diff --git a/src/cmd/link/internal/ld/symkind.go b/src/cmd/link/internal/ld/symkind.go
index 1f95f8afa8b1bca9b15a027e88c9d826233f1962..9d56142efa9803d6b40dfff1fe210605ff00f28d 100644 (file)
--- a/src/cmd/link/internal/ld/symkind.go
+++ b/src/cmd/link/internal/ld/symkind.go
@@ -106,7 +106,6 @@ const (
        SDWARFINFO
        SSUB       = SymKind(1 << 8)
        SMASK      = SymKind(SSUB - 1)
-       SHIDDEN    = SymKind(1 << 9)
        SCONTAINER = SymKind(1 << 10) // has a sub-symbol
 )
 

diff --git a/src/cmd/link/internal/ld/symtab.go b/src/cmd/link/internal/ld/symtab.go
index a35ece13add7cdeb7e1cea722d06e0f0b03ff801..8c20db81fff5ea13d3b5b73acd7e304b5ed0cfbc 100644 (file)
--- a/src/cmd/link/internal/ld/symtab.go
+++ b/src/cmd/link/internal/ld/symtab.go
@@ -127,7 +127,7 @@ func putelfsym(ctxt *Link, x *Symbol, s string, t SymbolType, addr int64, go_ *S
        // maybe one day STB_WEAK.
        bind := STB_GLOBAL
 
-       if x.Version != 0 || (x.Type&SHIDDEN != 0) || x.Attr.Local() {
+       if x.Version != 0 || x.Attr.VisibilityHidden() || x.Attr.Local() {
                bind = STB_LOCAL
        }
 
@@ -144,7 +144,11 @@ func putelfsym(ctxt *Link, x *Symbol, s string, t SymbolType, addr int64, go_ *S
                addr -= int64(xo.Sect.Vaddr)
        }
        other := STV_DEFAULT
-       if x.Type&SHIDDEN != 0 {
+       if x.Attr.VisibilityHidden() {
+               // TODO(mwhudson): We only set AttrVisibilityHidden in ldelf,
+               // i.e. when internally linking. But STV_HIDDEN visibility only
+               // matters in object files, i.e. when externally linking. So I
+               // don't think this makes a lot of sense.
                other = STV_HIDDEN
        }
        if (Buildmode == BuildmodeCArchive || Buildmode == BuildmodePIE || ctxt.DynlinkingGo()) && SysArch.Family == sys.PPC64 && typ == STT_FUNC && x.Name != "runtime.duffzero" && x.Name != "runtime.duffcopy" {