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cmd/link: mangle function names with ABI on PE

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When ABI wrappers are used, we may end up with two functions
having the same name. On ELF we mangle the name with ABI. Do the
same for PE.

TODO: other platforms?

Change-Id: If89f214a6286bc28c062c1aa1bad78dc353a9231
Reviewed-on: https://go-review.googlesource.com/c/go/+/304432
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
This commit is contained in:
Cherry Zhang 2021-03-24 11:19:19 -04:00
parent 6f62f852ef
commit fd5e0bd385
2 changed files with 40 additions and 33 deletions
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2
src/cmd/link/internal/ld/pe.go
View File

@ -694,6 +694,8 @@ func (f *peFile) writeSymbols(ctxt *Link) {
name = "_" + name
}
name = mangleABIName(ldr, s, name)
var peSymType uint16
if ctxt.IsExternal() {
peSymType = IMAGE_SYM_TYPE_NULL

71
src/cmd/link/internal/ld/symtab.go
View File

@ -104,39 +104,7 @@ func putelfsym(ctxt *Link, x loader.Sym, typ elf.SymType, curbind elf.SymBind) {
}
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 objabi.Experiment.RegabiWrappers {
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"
}
}
}
}
sname = mangleABIName(ldr, x, sname)
// One pass for each binding: elf.STB_LOCAL, elf.STB_GLOBAL,
// maybe one day elf.STB_WEAK.
@ -863,3 +831,40 @@ func setCarrierSize(typ sym.SymKind, sz int64) {
func isStaticTmp(name string) bool {
return strings.Contains(name, "."+obj.StaticNamePref)
}
// Mangle function name with ABI information.
func mangleABIName(ldr *loader.Loader, x loader.Sym, name string) string {
// 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: this is currently only used on ELF and PE. Other platforms?
//
// 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 !objabi.Experiment.RegabiWrappers {
return name
}
if !ldr.IsExternal(x) && ldr.SymType(x) == sym.STEXT {
// First case
if ldr.SymVersion(x) == sym.SymVerABIInternal {
if s2 := ldr.Lookup(name, sym.SymVerABI0); s2 != 0 && ldr.AttrCgoExportStatic(s2) && ldr.SymType(s2) == sym.STEXT {
name = name + ".abiinternal"
}
}
// Second case
if ldr.SymVersion(x) == sym.SymVerABI0 && !ldr.AttrCgoExportStatic(x) {
if s2 := ldr.Lookup(name, sym.SymVerABIInternal); s2 != 0 && ldr.SymType(s2) == sym.STEXT {
name = name + ".abi0"
}
}
}
return name
}