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cmd/internal/obj: don't emit args_stackmap for ABIInternal asm funcs

The compiler currently emits an "*.args_stackmap" symbol for all
bodyless functions, so that asm functions will have the proper stack
map. At the moment the code in the compiler that emits args_stackmap
assumes ABI0; to avoid misleading stackmaps, turn off args_stackmap
generation for non-ABI0 asm functions.

Updates #40724.

Change-Id: Ia5e3528d56da5fb107e799bd658e52496ba4a331
Reviewed-on: https://go-review.googlesource.com/c/go/+/309790
Trust: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This commit is contained in:
Than McIntosh 2021-04-13 13:49:55 -04:00
parent 25b25a9ed7
commit 4480c822ba

View File

@ -85,6 +85,13 @@ func Flushplist(ctxt *Link, plist *Plist, newprog ProgAlloc, myimportpath string
// wrapper function
continue
}
// The current args_stackmap generation in the compiler assumes
// that the function in question is ABI0, so avoid introducing
// an args_stackmap reference if the func is not ABI0 (better to
// have no stackmap than an incorrect/lying stackmap).
if s.ABI() != ABI0 {
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 {
@ -92,7 +99,6 @@ func Flushplist(ctxt *Link, plist *Plist, newprog ProgAlloc, myimportpath string
break
}
}
if !found {
p := Appendp(s.Func().Text, newprog)
p.As = AFUNCDATA