compiler, runtime: support and use single argument go:linkname

The gc compiler has started permitting go:linkname comments with a
single argument to mean that a function should be externally visible
outside the package.  Implement this in the Go frontend.

Change the libgo runtime package to use it, rather than repeating the
name just to export a function.

Remove a couple of unnecessary go:linkname comments on declarations.

Change-Id: Ie0feafd0be8498f7eab352dab09318ba4689f808
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/192197
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
diff --git a/go/gogo.cc b/go/gogo.cc
index f8114ec..d39a4fb 100644
--- a/go/gogo.cc
+++ b/go/gogo.cc
@@ -2531,9 +2531,22 @@
   if (no == NULL)
     go_error_at(loc, "%s is not defined", go_name.c_str());
   else if (no->is_function())
-    no->func_value()->set_asm_name(ext_name);
+    {
+      if (ext_name.empty())
+	no->func_value()->set_is_exported_by_linkname();
+      else
+	no->func_value()->set_asm_name(ext_name);
+    }
   else if (no->is_function_declaration())
-    no->func_declaration_value()->set_asm_name(ext_name);
+    {
+      if (ext_name.empty())
+	go_error_at(loc,
+		    ("//%<go:linkname%> missing external name "
+		     "for declaration of %s"),
+		    go_name.c_str());
+      else
+	no->func_declaration_value()->set_asm_name(ext_name);
+    }
   else
     go_error_at(loc,
 		("%s is not a function; "
@@ -5465,7 +5478,8 @@
     calls_recover_(false), is_recover_thunk_(false), has_recover_thunk_(false),
     calls_defer_retaddr_(false), is_type_specific_function_(false),
     in_unique_section_(false), export_for_inlining_(false),
-    is_inline_only_(false), is_referenced_by_inline_(false)
+    is_inline_only_(false), is_referenced_by_inline_(false),
+    is_exported_by_linkname_(false)
 {
 }
 
@@ -6220,6 +6234,11 @@
       if (this->is_referenced_by_inline_)
 	flags |= Backend::function_is_visible;
 
+      // A go:linkname directive can be used to force a function to be
+      // visible.
+      if (this->is_exported_by_linkname_)
+	flags |= Backend::function_is_visible;
+
       // If a function calls the predeclared recover function, we
       // can't inline it, because recover behaves differently in a
       // function passed directly to defer.  If this is a recover
diff --git a/go/gogo.h b/go/gogo.h
index 087e890..e742b6e 100644
--- a/go/gogo.h
+++ b/go/gogo.h
@@ -547,7 +547,9 @@
   { this->file_block_names_[name] = location; }
 
   // Add a linkname, from the go:linkname compiler directive.  This
-  // changes the externally visible name of go_name to be ext_name.
+  // changes the externally visible name of GO_NAME to be EXT_NAME.
+  // If EXT_NAME is the empty string, GO_NAME is unchanged, but the
+  // symbol is made publicly visible.
   void
   add_linkname(const std::string& go_name, bool is_exported,
 	       const std::string& ext_name, Location location);
@@ -1359,6 +1361,11 @@
   set_asm_name(const std::string& asm_name)
   { this->asm_name_ = asm_name; }
 
+  // Mark this symbol as exported by a linkname directive.
+  void
+  set_is_exported_by_linkname()
+  { this->is_exported_by_linkname_ = true; }
+
   // Return the pragmas for this function.
   unsigned int
   pragmas() const
@@ -1706,6 +1713,9 @@
   // True if this function is referenced from an inlined body that
   // will be put into the export data.
   bool is_referenced_by_inline_ : 1;
+  // True if we should make this function visible to other packages
+  // because of a go:linkname directive.
+  bool is_exported_by_linkname_ : 1;
 };
 
 // A snapshot of the current binding state.
diff --git a/go/lex.cc b/go/lex.cc
index 3276de4..f023613 100644
--- a/go/lex.cc
+++ b/go/lex.cc
@@ -1996,7 +1996,7 @@
 
 	      while (ps < pend && *ps != ' ' && *ps != '\t')
 		++ps;
-	      if (ps < pend)
+	      if (ps <= pend)
 		go_name = std::string(pg, ps - pg);
 	      while (ps < pend && (*ps == ' ' || *ps == '\t'))
 		++ps;
@@ -2015,8 +2015,8 @@
 	      ext_name.clear();
 	    }
 	}
-      if (go_name.empty() || ext_name.empty())
-	go_error_at(loc, "usage: %<//go:linkname%> localname linkname");
+      if (go_name.empty())
+	go_error_at(loc, "usage: %<//go:linkname%> localname [linkname]");
       else
 	{
 	  if (this->linknames_ == NULL)
diff --git a/go/lex.h b/go/lex.h
index 59b770c..3be3806 100644
--- a/go/lex.h
+++ b/go/lex.h
@@ -380,7 +380,7 @@
 
   struct Linkname
   {
-    std::string ext_name;	// External name.
+    std::string ext_name;	// External name; empty to just export.
     bool is_exported;		// Whether the internal name is exported.
     Location loc;		// Location of go:linkname directive.
 
diff --git a/libgo/go/runtime/alg.go b/libgo/go/runtime/alg.go
index a2bb5bb..0daddf1 100644
--- a/libgo/go/runtime/alg.go
+++ b/libgo/go/runtime/alg.go
@@ -10,44 +10,43 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname memhash0 runtime.memhash0
-//go:linkname memhash8 runtime.memhash8
-//go:linkname memhash16 runtime.memhash16
-//go:linkname memhash32 runtime.memhash32
-//go:linkname memhash64 runtime.memhash64
-//go:linkname memhash128 runtime.memhash128
-//go:linkname strhash runtime.strhash
-//go:linkname f32hash runtime.f32hash
-//go:linkname f64hash runtime.f64hash
-//go:linkname c64hash runtime.c64hash
-//go:linkname c128hash runtime.c128hash
-//go:linkname interhash runtime.interhash
-//go:linkname nilinterhash runtime.nilinterhash
-//go:linkname memequal0 runtime.memequal0
-//go:linkname memequal8 runtime.memequal8
-//go:linkname memequal16 runtime.memequal16
-//go:linkname memequal32 runtime.memequal32
-//go:linkname memequal64 runtime.memequal64
-//go:linkname memequal128 runtime.memequal128
-//go:linkname strequal runtime.strequal
-//go:linkname f32equal runtime.f32equal
-//go:linkname f64equal runtime.f64equal
-//go:linkname c64equal runtime.c64equal
-//go:linkname c128equal runtime.c128equal
-//go:linkname interequal runtime.interequal
-//go:linkname nilinterequal runtime.nilinterequal
-//go:linkname efaceeq runtime.efaceeq
-//go:linkname ifaceeq runtime.ifaceeq
-//go:linkname ifacevaleq runtime.ifacevaleq
-//go:linkname ifaceefaceeq runtime.ifaceefaceeq
-//go:linkname efacevaleq runtime.efacevaleq
-//go:linkname cmpstring runtime.cmpstring
+//go:linkname memhash0
+//go:linkname memhash8
+//go:linkname memhash16
+//go:linkname memhash32
+//go:linkname memhash64
+//go:linkname memhash128
+//go:linkname strhash
+//go:linkname f32hash
+//go:linkname f64hash
+//go:linkname c64hash
+//go:linkname c128hash
+//go:linkname interhash
+//go:linkname nilinterhash
+//go:linkname memequal0
+//go:linkname memequal8
+//go:linkname memequal16
+//go:linkname memequal32
+//go:linkname memequal64
+//go:linkname memequal128
+//go:linkname strequal
+//go:linkname f32equal
+//go:linkname f64equal
+//go:linkname c64equal
+//go:linkname c128equal
+//go:linkname interequal
+//go:linkname nilinterequal
+//go:linkname efaceeq
+//go:linkname ifaceeq
+//go:linkname ifacevaleq
+//go:linkname ifaceefaceeq
+//go:linkname efacevaleq
+//go:linkname cmpstring
 //
 // Temporary to be called from C code.
-//go:linkname alginit runtime.alginit
+//go:linkname alginit
 
 const (
 	c0 = uintptr((8-sys.PtrSize)/4*2860486313 + (sys.PtrSize-4)/4*33054211828000289)
diff --git a/libgo/go/runtime/cgocall.go b/libgo/go/runtime/cgocall.go
index 57b42ff..69c3e44 100644
--- a/libgo/go/runtime/cgocall.go
+++ b/libgo/go/runtime/cgocall.go
@@ -12,8 +12,8 @@
 )
 
 // Functions called by cgo-generated code.
-//go:linkname cgoCheckPointer runtime.cgoCheckPointer
-//go:linkname cgoCheckResult runtime.cgoCheckResult
+//go:linkname cgoCheckPointer
+//go:linkname cgoCheckResult
 
 // Pointer checking for cgo code.
 
diff --git a/libgo/go/runtime/chan.go b/libgo/go/runtime/chan.go
index 6c8d6f7..a1216cf 100644
--- a/libgo/go/runtime/chan.go
+++ b/libgo/go/runtime/chan.go
@@ -23,18 +23,17 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname makechan runtime.makechan
-//go:linkname makechan64 runtime.makechan64
-//go:linkname chansend1 runtime.chansend1
-//go:linkname chanrecv1 runtime.chanrecv1
-//go:linkname chanrecv2 runtime.chanrecv2
-//go:linkname closechan runtime.closechan
-//go:linkname selectnbsend runtime.selectnbsend
-//go:linkname selectnbrecv runtime.selectnbrecv
-//go:linkname selectnbrecv2 runtime.selectnbrecv2
+//go:linkname makechan
+//go:linkname makechan64
+//go:linkname chansend1
+//go:linkname chanrecv1
+//go:linkname chanrecv2
+//go:linkname closechan
+//go:linkname selectnbsend
+//go:linkname selectnbrecv
+//go:linkname selectnbrecv2
 
 const (
 	maxAlign  = 8
diff --git a/libgo/go/runtime/ffi.go b/libgo/go/runtime/ffi.go
index e8088ec..be79224 100644
--- a/libgo/go/runtime/ffi.go
+++ b/libgo/go/runtime/ffi.go
@@ -37,7 +37,7 @@
 func ffi_prep_cif(*_ffi_cif, _ffi_abi, uint32, *__ffi_type, **__ffi_type) _ffi_status
 
 // ffiFuncToCIF is called from C code.
-//go:linkname ffiFuncToCIF runtime.ffiFuncToCIF
+//go:linkname ffiFuncToCIF
 
 // ffiFuncToCIF builds an _ffi_cif struct for function described by ft.
 func ffiFuncToCIF(ft *functype, isInterface bool, isMethod bool, cif *_ffi_cif) {
diff --git a/libgo/go/runtime/hash32.go b/libgo/go/runtime/hash32.go
index 3449127..fba6bc3 100644
--- a/libgo/go/runtime/hash32.go
+++ b/libgo/go/runtime/hash32.go
@@ -12,10 +12,9 @@
 
 import "unsafe"
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname memhash runtime.memhash
+//go:linkname memhash
 
 const (
 	// Constants for multiplication: four random odd 32-bit numbers.
diff --git a/libgo/go/runtime/hash64.go b/libgo/go/runtime/hash64.go
index 7c6513e..3f94256 100644
--- a/libgo/go/runtime/hash64.go
+++ b/libgo/go/runtime/hash64.go
@@ -12,10 +12,9 @@
 
 import "unsafe"
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname memhash runtime.memhash
+//go:linkname memhash
 
 const (
 	// Constants for multiplication: four random odd 64-bit numbers.
diff --git a/libgo/go/runtime/iface.go b/libgo/go/runtime/iface.go
index d434f9e..3fa5dd6 100644
--- a/libgo/go/runtime/iface.go
+++ b/libgo/go/runtime/iface.go
@@ -10,23 +10,22 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname requireitab runtime.requireitab
-//go:linkname assertitab runtime.assertitab
-//go:linkname panicdottype runtime.panicdottype
-//go:linkname ifaceE2E2 runtime.ifaceE2E2
-//go:linkname ifaceI2E2 runtime.ifaceI2E2
-//go:linkname ifaceE2I2 runtime.ifaceE2I2
-//go:linkname ifaceI2I2 runtime.ifaceI2I2
-//go:linkname ifaceE2T2P runtime.ifaceE2T2P
-//go:linkname ifaceI2T2P runtime.ifaceI2T2P
-//go:linkname ifaceE2T2 runtime.ifaceE2T2
-//go:linkname ifaceI2T2 runtime.ifaceI2T2
-//go:linkname ifaceT2Ip runtime.ifaceT2Ip
+//go:linkname requireitab
+//go:linkname assertitab
+//go:linkname panicdottype
+//go:linkname ifaceE2E2
+//go:linkname ifaceI2E2
+//go:linkname ifaceE2I2
+//go:linkname ifaceI2I2
+//go:linkname ifaceE2T2P
+//go:linkname ifaceI2T2P
+//go:linkname ifaceE2T2
+//go:linkname ifaceI2T2
+//go:linkname ifaceT2Ip
 // Temporary for C code to call:
-//go:linkname getitab runtime.getitab
+//go:linkname getitab
 
 // The gccgo itab structure is different than the gc one.
 //
diff --git a/libgo/go/runtime/lock_futex.go b/libgo/go/runtime/lock_futex.go
index 9cede2d..6f86e91 100644
--- a/libgo/go/runtime/lock_futex.go
+++ b/libgo/go/runtime/lock_futex.go
@@ -12,16 +12,15 @@
 )
 
 // For gccgo, while we still have C runtime code, use go:linkname to
-// rename some functions to themselves, so that the compiler will
-// export them.
+// export some functions.
 //
-//go:linkname lock runtime.lock
-//go:linkname unlock runtime.unlock
-//go:linkname noteclear runtime.noteclear
-//go:linkname notewakeup runtime.notewakeup
-//go:linkname notesleep runtime.notesleep
-//go:linkname notetsleep runtime.notetsleep
-//go:linkname notetsleepg runtime.notetsleepg
+//go:linkname lock
+//go:linkname unlock
+//go:linkname noteclear
+//go:linkname notewakeup
+//go:linkname notesleep
+//go:linkname notetsleep
+//go:linkname notetsleepg
 
 // This implementation depends on OS-specific implementations of
 //
diff --git a/libgo/go/runtime/lock_sema.go b/libgo/go/runtime/lock_sema.go
index 7e69114..bf9211a 100644
--- a/libgo/go/runtime/lock_sema.go
+++ b/libgo/go/runtime/lock_sema.go
@@ -12,16 +12,15 @@
 )
 
 // For gccgo, while we still have C runtime code, use go:linkname to
-// rename some functions to themselves, so that the compiler will
-// export them.
+// export some functions.
 //
-//go:linkname lock runtime.lock
-//go:linkname unlock runtime.unlock
-//go:linkname noteclear runtime.noteclear
-//go:linkname notewakeup runtime.notewakeup
-//go:linkname notesleep runtime.notesleep
-//go:linkname notetsleep runtime.notetsleep
-//go:linkname notetsleepg runtime.notetsleepg
+//go:linkname lock
+//go:linkname unlock
+//go:linkname noteclear
+//go:linkname notewakeup
+//go:linkname notesleep
+//go:linkname notetsleep
+//go:linkname notetsleepg
 
 // This implementation depends on OS-specific implementations of
 //
diff --git a/libgo/go/runtime/malloc.go b/libgo/go/runtime/malloc.go
index 68e5494..e1e908b 100644
--- a/libgo/go/runtime/malloc.go
+++ b/libgo/go/runtime/malloc.go
@@ -114,13 +114,12 @@
 // C function to get the end of the program's memory.
 func getEnd() uintptr
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname newobject runtime.newobject
+//go:linkname newobject
 
 // Functions called by C code.
-//go:linkname mallocgc runtime.mallocgc
+//go:linkname mallocgc
 
 const (
 	debugMalloc = false
diff --git a/libgo/go/runtime/map.go b/libgo/go/runtime/map.go
index b210f5a..eebb210 100644
--- a/libgo/go/runtime/map.go
+++ b/libgo/go/runtime/map.go
@@ -60,21 +60,20 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname makemap runtime.makemap
-//go:linkname makemap64 runtime.makemap64
-//go:linkname makemap_small runtime.makemap_small
-//go:linkname mapaccess1 runtime.mapaccess1
-//go:linkname mapaccess2 runtime.mapaccess2
-//go:linkname mapaccess1_fat runtime.mapaccess1_fat
-//go:linkname mapaccess2_fat runtime.mapaccess2_fat
-//go:linkname mapassign runtime.mapassign
-//go:linkname mapdelete runtime.mapdelete
-//go:linkname mapclear runtime.mapclear
-//go:linkname mapiterinit runtime.mapiterinit
-//go:linkname mapiternext runtime.mapiternext
+//go:linkname makemap
+//go:linkname makemap64
+//go:linkname makemap_small
+//go:linkname mapaccess1
+//go:linkname mapaccess2
+//go:linkname mapaccess1_fat
+//go:linkname mapaccess2_fat
+//go:linkname mapassign
+//go:linkname mapdelete
+//go:linkname mapclear
+//go:linkname mapiterinit
+//go:linkname mapiternext
 
 const (
 	// Maximum number of key/value pairs a bucket can hold.
diff --git a/libgo/go/runtime/map_fast32.go b/libgo/go/runtime/map_fast32.go
index 07a35e1..67d6df8 100644
--- a/libgo/go/runtime/map_fast32.go
+++ b/libgo/go/runtime/map_fast32.go
@@ -9,14 +9,13 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname mapaccess1_fast32 runtime.mapaccess1_fast32
-//go:linkname mapaccess2_fast32 runtime.mapaccess2_fast32
-//go:linkname mapassign_fast32 runtime.mapassign_fast32
-//go:linkname mapassign_fast32ptr runtime.mapassign_fast32ptr
-//go:linkname mapdelete_fast32 runtime.mapdelete_fast32
+//go:linkname mapaccess1_fast32
+//go:linkname mapaccess2_fast32
+//go:linkname mapassign_fast32
+//go:linkname mapassign_fast32ptr
+//go:linkname mapdelete_fast32
 
 func mapaccess1_fast32(t *maptype, h *hmap, key uint32) unsafe.Pointer {
 	if raceenabled && h != nil {
diff --git a/libgo/go/runtime/map_fast64.go b/libgo/go/runtime/map_fast64.go
index d21bf06..b62ecb1 100644
--- a/libgo/go/runtime/map_fast64.go
+++ b/libgo/go/runtime/map_fast64.go
@@ -9,14 +9,13 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname mapaccess1_fast64 runtime.mapaccess1_fast64
-//go:linkname mapaccess2_fast64 runtime.mapaccess2_fast64
-//go:linkname mapassign_fast64 runtime.mapassign_fast64
-//go:linkname mapassign_fast64ptr runtime.mapassign_fast64ptr
-//go:linkname mapdelete_fast64 runtime.mapdelete_fast64
+//go:linkname mapaccess1_fast64
+//go:linkname mapaccess2_fast64
+//go:linkname mapassign_fast64
+//go:linkname mapassign_fast64ptr
+//go:linkname mapdelete_fast64
 
 func mapaccess1_fast64(t *maptype, h *hmap, key uint64) unsafe.Pointer {
 	if raceenabled && h != nil {
diff --git a/libgo/go/runtime/map_faststr.go b/libgo/go/runtime/map_faststr.go
index 083980f..2202695 100644
--- a/libgo/go/runtime/map_faststr.go
+++ b/libgo/go/runtime/map_faststr.go
@@ -9,13 +9,12 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname mapaccess1_faststr runtime.mapaccess1_faststr
-//go:linkname mapaccess2_faststr runtime.mapaccess2_faststr
-//go:linkname mapassign_faststr runtime.mapassign_faststr
-//go:linkname mapdelete_faststr runtime.mapdelete_faststr
+//go:linkname mapaccess1_faststr
+//go:linkname mapaccess2_faststr
+//go:linkname mapassign_faststr
+//go:linkname mapdelete_faststr
 
 func mapaccess1_faststr(t *maptype, h *hmap, ky string) unsafe.Pointer {
 	if raceenabled && h != nil {
diff --git a/libgo/go/runtime/mbarrier.go b/libgo/go/runtime/mbarrier.go
index 89febb9..00e5eb8 100644
--- a/libgo/go/runtime/mbarrier.go
+++ b/libgo/go/runtime/mbarrier.go
@@ -18,12 +18,11 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname typedmemmove runtime.typedmemmove
-//go:linkname typedslicecopy runtime.typedslicecopy
-//go:linkname memclrHasPointers runtime.memclrHasPointers
+//go:linkname typedmemmove
+//go:linkname typedslicecopy
+//go:linkname memclrHasPointers
 
 // Go uses a hybrid barrier that combines a Yuasa-style deletion
 // barrier—which shades the object whose reference is being
diff --git a/libgo/go/runtime/mem_gccgo.go b/libgo/go/runtime/mem_gccgo.go
index 9874678..5ce816c 100644
--- a/libgo/go/runtime/mem_gccgo.go
+++ b/libgo/go/runtime/mem_gccgo.go
@@ -12,8 +12,8 @@
 )
 
 // Functions called by C code.
-//go:linkname sysAlloc runtime.sysAlloc
-//go:linkname sysFree runtime.sysFree
+//go:linkname sysAlloc
+//go:linkname sysFree
 
 //extern mmap
 func sysMmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uintptr) unsafe.Pointer
diff --git a/libgo/go/runtime/mgc_gccgo.go b/libgo/go/runtime/mgc_gccgo.go
index 8504517..d7ae260 100644
--- a/libgo/go/runtime/mgc_gccgo.go
+++ b/libgo/go/runtime/mgc_gccgo.go
@@ -11,10 +11,9 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname gcWriteBarrier runtime.gcWriteBarrier
+//go:linkname gcWriteBarrier
 
 // gcRoot is a single GC root: a variable plus a ptrmask.
 //go:notinheap
@@ -130,7 +129,7 @@
 }
 
 // registerGCRoots is called by compiler-generated code.
-//go:linkname registerGCRoots runtime.registerGCRoots
+//go:linkname registerGCRoots
 
 // registerGCRoots is called by init functions to register the GC
 // roots for a package.  The init functions are run sequentially at
diff --git a/libgo/go/runtime/mgcmark.go b/libgo/go/runtime/mgcmark.go
index 2463a48..b6b69dd 100644
--- a/libgo/go/runtime/mgcmark.go
+++ b/libgo/go/runtime/mgcmark.go
@@ -1042,7 +1042,7 @@
 	gcw.scanWork += int64(i)
 }
 
-//go:linkname scanstackblock runtime.scanstackblock
+//go:linkname scanstackblock
 
 // scanstackblock is called by the stack scanning code in C to
 // actually find and mark pointers in the stack block. This is like
@@ -1064,7 +1064,7 @@
 
 // scanstackblockwithmap is like scanstackblock, but with an explicit
 // pointer bitmap. This is used only when precise stack scan is enabled.
-//go:linkname scanstackblockwithmap runtime.scanstackblockwithmap
+//go:linkname scanstackblockwithmap
 //go:nowritebarrier
 func scanstackblockwithmap(pc, b0, n0 uintptr, ptrmask *uint8, gcw *gcWork) {
 	// Use local copies of original parameters, so that a stack trace
diff --git a/libgo/go/runtime/netpoll.go b/libgo/go/runtime/netpoll.go
index 3515922..00c7f52 100644
--- a/libgo/go/runtime/netpoll.go
+++ b/libgo/go/runtime/netpoll.go
@@ -12,7 +12,7 @@
 )
 
 // Export temporarily for gccgo's C code to call:
-//go:linkname netpoll runtime.netpoll
+//go:linkname netpoll
 
 // Integrated network poller (platform-independent part).
 // A particular implementation (epoll/kqueue) must define the following functions:
diff --git a/libgo/go/runtime/os_gccgo.go b/libgo/go/runtime/os_gccgo.go
index 08511fd..ef33d67 100644
--- a/libgo/go/runtime/os_gccgo.go
+++ b/libgo/go/runtime/os_gccgo.go
@@ -9,7 +9,7 @@
 )
 
 // For C code to call:
-//go:linkname minit runtime.minit
+//go:linkname minit
 
 func goenvs() {
 	goenvs_unix()
diff --git a/libgo/go/runtime/panic.go b/libgo/go/runtime/panic.go
index 5868430..8e56bbe 100644
--- a/libgo/go/runtime/panic.go
+++ b/libgo/go/runtime/panic.go
@@ -9,39 +9,38 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname deferproc runtime.deferproc
-//go:linkname deferprocStack runtime.deferprocStack
-//go:linkname deferreturn runtime.deferreturn
-//go:linkname setdeferretaddr runtime.setdeferretaddr
-//go:linkname checkdefer runtime.checkdefer
-//go:linkname gopanic runtime.gopanic
-//go:linkname canrecover runtime.canrecover
-//go:linkname makefuncfficanrecover runtime.makefuncfficanrecover
-//go:linkname makefuncreturning runtime.makefuncreturning
-//go:linkname gorecover runtime.gorecover
-//go:linkname deferredrecover runtime.deferredrecover
-//go:linkname goPanicIndex runtime.goPanicIndex
-//go:linkname goPanicIndexU runtime.goPanicIndexU
-//go:linkname goPanicSliceAlen runtime.goPanicSliceAlen
-//go:linkname goPanicSliceAlenU runtime.goPanicSliceAlenU
-//go:linkname goPanicSliceAcap runtime.goPanicSliceAcap
-//go:linkname goPanicSliceAcapU runtime.goPanicSliceAcapU
-//go:linkname goPanicSliceB runtime.goPanicSliceB
-//go:linkname goPanicSliceBU runtime.goPanicSliceBU
-//go:linkname goPanicSlice3Alen runtime.goPanicSlice3Alen
-//go:linkname goPanicSlice3AlenU runtime.goPanicSlice3AlenU
-//go:linkname goPanicSlice3Acap runtime.goPanicSlice3Acap
-//go:linkname goPanicSlice3AcapU runtime.goPanicSlice3AcapU
-//go:linkname goPanicSlice3B runtime.goPanicSlice3B
-//go:linkname goPanicSlice3BU runtime.goPanicSlice3BU
-//go:linkname goPanicSlice3C runtime.goPanicSlice3C
-//go:linkname goPanicSlice3CU runtime.goPanicSlice3CU
-//go:linkname panicmem runtime.panicmem
+//go:linkname deferproc
+//go:linkname deferprocStack
+//go:linkname deferreturn
+//go:linkname setdeferretaddr
+//go:linkname checkdefer
+//go:linkname gopanic
+//go:linkname canrecover
+//go:linkname makefuncfficanrecover
+//go:linkname makefuncreturning
+//go:linkname gorecover
+//go:linkname deferredrecover
+//go:linkname goPanicIndex
+//go:linkname goPanicIndexU
+//go:linkname goPanicSliceAlen
+//go:linkname goPanicSliceAlenU
+//go:linkname goPanicSliceAcap
+//go:linkname goPanicSliceAcapU
+//go:linkname goPanicSliceB
+//go:linkname goPanicSliceBU
+//go:linkname goPanicSlice3Alen
+//go:linkname goPanicSlice3AlenU
+//go:linkname goPanicSlice3Acap
+//go:linkname goPanicSlice3AcapU
+//go:linkname goPanicSlice3B
+//go:linkname goPanicSlice3BU
+//go:linkname goPanicSlice3C
+//go:linkname goPanicSlice3CU
+//go:linkname panicmem
 // Temporary for C code to call:
-//go:linkname throw runtime.throw
+//go:linkname throw
 
 // Check to make sure we can really generate a panic. If the panic
 // was generated from the runtime, or from inside malloc, then convert
diff --git a/libgo/go/runtime/panic32.go b/libgo/go/runtime/panic32.go
index c8861c9..fa314af 100644
--- a/libgo/go/runtime/panic32.go
+++ b/libgo/go/runtime/panic32.go
@@ -6,25 +6,24 @@
 
 import _ "unsafe" // for go:linkname
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname goPanicExtendIndex runtime.goPanicExtendIndex
-//go:linkname goPanicExtendIndexU runtime.goPanicExtendIndexU
-//go:linkname goPanicExtendSliceAlen runtime.goPanicExtendSliceAlen
-//go:linkname goPanicExtendSliceAlenU runtime.goPanicExtendSliceAlenU
-//go:linkname goPanicExtendSliceAcap runtime.goPanicExtendSliceAcap
-//go:linkname goPanicExtendSliceAcapU runtime.goPanicExtendSliceAcapU
-//go:linkname goPanicExtendSliceB runtime.goPanicExtendSliceB
-//go:linkname goPanicExtendSliceBU runtime.goPanicExtendSliceBU
-//go:linkname goPanicExtendSlice3Alen runtime.goPanicExtendSlice3Alen
-//go:linkname goPanicExtendSlice3AlenU runtime.goPanicExtendSlice3AlenU
-//go:linkname goPanicExtendSlice3Acap runtime.goPanicExtendSlice3Acap
-//go:linkname goPanicExtendSlice3AcapU runtime.goPanicExtendSlice3AcapU
-//go:linkname goPanicExtendSlice3B runtime.goPanicExtendSlice3B
-//go:linkname goPanicExtendSlice3BU runtime.goPanicExtendSlice3BU
-//go:linkname goPanicExtendSlice3C runtime.goPanicExtendSlice3C
-//go:linkname goPanicExtendSlice3CU runtime.goPanicExtendSlice3CU
+//go:linkname goPanicExtendIndex
+//go:linkname goPanicExtendIndexU
+//go:linkname goPanicExtendSliceAlen
+//go:linkname goPanicExtendSliceAlenU
+//go:linkname goPanicExtendSliceAcap
+//go:linkname goPanicExtendSliceAcapU
+//go:linkname goPanicExtendSliceB
+//go:linkname goPanicExtendSliceBU
+//go:linkname goPanicExtendSlice3Alen
+//go:linkname goPanicExtendSlice3AlenU
+//go:linkname goPanicExtendSlice3Acap
+//go:linkname goPanicExtendSlice3AcapU
+//go:linkname goPanicExtendSlice3B
+//go:linkname goPanicExtendSlice3BU
+//go:linkname goPanicExtendSlice3C
+//go:linkname goPanicExtendSlice3CU
 
 // Additional index/slice error paths for 32-bit platforms.
 // Used when the high word of a 64-bit index is not zero.
diff --git a/libgo/go/runtime/print.go b/libgo/go/runtime/print.go
index 14d546d..7729ddc 100644
--- a/libgo/go/runtime/print.go
+++ b/libgo/go/runtime/print.go
@@ -9,27 +9,26 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname printbool runtime.printbool
-//go:linkname printfloat runtime.printfloat
-//go:linkname printint runtime.printint
-//go:linkname printhex runtime.printhex
-//go:linkname printuint runtime.printuint
-//go:linkname printcomplex runtime.printcomplex
-//go:linkname printstring runtime.printstring
-//go:linkname printpointer runtime.printpointer
-//go:linkname printiface runtime.printiface
-//go:linkname printeface runtime.printeface
-//go:linkname printslice runtime.printslice
-//go:linkname printnl runtime.printnl
-//go:linkname printsp runtime.printsp
-//go:linkname printlock runtime.printlock
-//go:linkname printunlock runtime.printunlock
+//go:linkname printbool
+//go:linkname printfloat
+//go:linkname printint
+//go:linkname printhex
+//go:linkname printuint
+//go:linkname printcomplex
+//go:linkname printstring
+//go:linkname printpointer
+//go:linkname printiface
+//go:linkname printeface
+//go:linkname printslice
+//go:linkname printnl
+//go:linkname printsp
+//go:linkname printlock
+//go:linkname printunlock
 // Temporary for C code to call:
-//go:linkname gwrite runtime.gwrite
-//go:linkname printhex runtime.printhex
+//go:linkname gwrite
+//go:linkname printhex
 
 // The compiler knows that a print of a value of this type
 // should use printhex instead of printuint (decimal).
diff --git a/libgo/go/runtime/proc.go b/libgo/go/runtime/proc.go
index b40198e..fa85d26 100644
--- a/libgo/go/runtime/proc.go
+++ b/libgo/go/runtime/proc.go
@@ -12,37 +12,37 @@
 )
 
 // Functions called by C code.
-//go:linkname main runtime.main
-//go:linkname goparkunlock runtime.goparkunlock
-//go:linkname newextram runtime.newextram
-//go:linkname acquirep runtime.acquirep
-//go:linkname releasep runtime.releasep
-//go:linkname incidlelocked runtime.incidlelocked
-//go:linkname ginit runtime.ginit
-//go:linkname schedinit runtime.schedinit
-//go:linkname ready runtime.ready
-//go:linkname stopm runtime.stopm
-//go:linkname handoffp runtime.handoffp
-//go:linkname wakep runtime.wakep
-//go:linkname stoplockedm runtime.stoplockedm
-//go:linkname schedule runtime.schedule
-//go:linkname execute runtime.execute
-//go:linkname goexit1 runtime.goexit1
-//go:linkname reentersyscall runtime.reentersyscall
-//go:linkname reentersyscallblock runtime.reentersyscallblock
-//go:linkname exitsyscall runtime.exitsyscall
-//go:linkname gfget runtime.gfget
-//go:linkname kickoff runtime.kickoff
-//go:linkname mstart1 runtime.mstart1
-//go:linkname mexit runtime.mexit
-//go:linkname globrunqput runtime.globrunqput
-//go:linkname pidleget runtime.pidleget
+//go:linkname main
+//go:linkname goparkunlock
+//go:linkname newextram
+//go:linkname acquirep
+//go:linkname releasep
+//go:linkname incidlelocked
+//go:linkname ginit
+//go:linkname schedinit
+//go:linkname ready
+//go:linkname stopm
+//go:linkname handoffp
+//go:linkname wakep
+//go:linkname stoplockedm
+//go:linkname schedule
+//go:linkname execute
+//go:linkname goexit1
+//go:linkname reentersyscall
+//go:linkname reentersyscallblock
+//go:linkname exitsyscall
+//go:linkname gfget
+//go:linkname kickoff
+//go:linkname mstart1
+//go:linkname mexit
+//go:linkname globrunqput
+//go:linkname pidleget
 
 // Exported for test (see runtime/testdata/testprogcgo/dropm_stub.go).
-//go:linkname getm runtime.getm
+//go:linkname getm
 
 // Function called by misc/cgo/test.
-//go:linkname lockedOSThread runtime.lockedOSThread
+//go:linkname lockedOSThread
 
 // C functions for thread and context management.
 func newosproc(*m)
diff --git a/libgo/go/runtime/runtime.go b/libgo/go/runtime/runtime.go
index d19d6af..abc5eab 100644
--- a/libgo/go/runtime/runtime.go
+++ b/libgo/go/runtime/runtime.go
@@ -14,10 +14,9 @@
 //go:generate go run mkfastlog2table.go
 
 // For gccgo, while we still have C runtime code, use go:linkname to
-// rename some functions to themselves, so that the compiler will
-// export them.
+// export some functions.
 //
-//go:linkname tickspersecond runtime.tickspersecond
+//go:linkname tickspersecond
 
 var ticksLock mutex
 var ticksVal uint64
diff --git a/libgo/go/runtime/runtime1.go b/libgo/go/runtime/runtime1.go
index 2424f20..d9309cc 100644
--- a/libgo/go/runtime/runtime1.go
+++ b/libgo/go/runtime/runtime1.go
@@ -11,16 +11,15 @@
 )
 
 // For gccgo, while we still have C runtime code, use go:linkname to
-// rename some functions to themselves, so that the compiler will
-// export them.
+// export some functions to themselves.
 //
-//go:linkname gotraceback runtime.gotraceback
-//go:linkname args runtime.args
-//go:linkname goargs runtime.goargs
-//go:linkname check runtime.check
-//go:linkname goenvs_unix runtime.goenvs_unix
-//go:linkname parsedebugvars runtime.parsedebugvars
-//go:linkname timediv runtime.timediv
+//go:linkname gotraceback
+//go:linkname args
+//go:linkname goargs
+//go:linkname check
+//go:linkname goenvs_unix
+//go:linkname parsedebugvars
+//go:linkname timediv
 
 // Keep a cached value to make gotraceback fast,
 // since we call it on every call to gentraceback.
diff --git a/libgo/go/runtime/runtime2.go b/libgo/go/runtime/runtime2.go
index e4dfbdf..fd77c4c 100644
--- a/libgo/go/runtime/runtime2.go
+++ b/libgo/go/runtime/runtime2.go
@@ -930,7 +930,7 @@
 
 // getMemstats returns a pointer to the internal memstats variable,
 // for C code.
-//go:linkname getMemstats runtime.getMemstats
+//go:linkname getMemstats
 func getMemstats() *mstats {
 	return &memstats
 }
diff --git a/libgo/go/runtime/select.go b/libgo/go/runtime/select.go
index 16de9b8..41e5e88 100644
--- a/libgo/go/runtime/select.go
+++ b/libgo/go/runtime/select.go
@@ -10,11 +10,10 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname selectgo runtime.selectgo
-//go:linkname block runtime.block
+//go:linkname selectgo
+//go:linkname block
 
 const debugSelect = false
 
diff --git a/libgo/go/runtime/signal_unix.go b/libgo/go/runtime/signal_unix.go
index 0ba21e1..e1bab8c 100644
--- a/libgo/go/runtime/signal_unix.go
+++ b/libgo/go/runtime/signal_unix.go
@@ -12,8 +12,8 @@
 )
 
 // For gccgo's C code to call:
-//go:linkname initsig runtime.initsig
-//go:linkname sigtrampgo runtime.sigtrampgo
+//go:linkname initsig
+//go:linkname sigtrampgo
 
 // sigTabT is the type of an entry in the global sigtable array.
 // sigtable is inherently system dependent, and appears in OS-specific files,
diff --git a/libgo/go/runtime/slice.go b/libgo/go/runtime/slice.go
index 9137951..4b15f82 100644
--- a/libgo/go/runtime/slice.go
+++ b/libgo/go/runtime/slice.go
@@ -10,14 +10,13 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname makeslice runtime.makeslice
-//go:linkname makeslice64 runtime.makeslice64
-//go:linkname growslice runtime.growslice
-//go:linkname slicecopy runtime.slicecopy
-//go:linkname slicestringcopy runtime.slicestringcopy
+//go:linkname makeslice
+//go:linkname makeslice64
+//go:linkname growslice
+//go:linkname slicecopy
+//go:linkname slicestringcopy
 
 type slice struct {
 	array unsafe.Pointer
diff --git a/libgo/go/runtime/string.go b/libgo/go/runtime/string.go
index 9bcfc99..d225dc3 100644
--- a/libgo/go/runtime/string.go
+++ b/libgo/go/runtime/string.go
@@ -9,19 +9,18 @@
 	"unsafe"
 )
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname concatstrings runtime.concatstrings
-//go:linkname slicebytetostring runtime.slicebytetostring
-//go:linkname slicebytetostringtmp runtime.slicebytetostringtmp
-//go:linkname stringtoslicebyte runtime.stringtoslicebyte
-//go:linkname stringtoslicerune runtime.stringtoslicerune
-//go:linkname slicerunetostring runtime.slicerunetostring
-//go:linkname intstring runtime.intstring
+//go:linkname concatstrings
+//go:linkname slicebytetostring
+//go:linkname slicebytetostringtmp
+//go:linkname stringtoslicebyte
+//go:linkname stringtoslicerune
+//go:linkname slicerunetostring
+//go:linkname intstring
 // Temporary for C code to call:
-//go:linkname gostringnocopy runtime.gostringnocopy
-//go:linkname findnull runtime.findnull
+//go:linkname gostringnocopy
+//go:linkname findnull
 
 // The constant is known to the compiler.
 // There is no fundamental theory behind this number.
diff --git a/libgo/go/runtime/stubs.go b/libgo/go/runtime/stubs.go
index a81bf92..4662251 100644
--- a/libgo/go/runtime/stubs.go
+++ b/libgo/go/runtime/stubs.go
@@ -165,7 +165,6 @@
 
 func asminit() {}
 
-//go:linkname reflectcall runtime.reflectcall
 //go:noescape
 func reflectcall(fntype *functype, fn *funcval, isInterface, isMethod bool, params, results *unsafe.Pointer)
 
@@ -280,13 +279,13 @@
 func syscall(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) uintptr
 
 // For gccgo, to communicate from the C code to the Go code.
-//go:linkname setIsCgo runtime.setIsCgo
+//go:linkname setIsCgo
 func setIsCgo() {
 	iscgo = true
 }
 
 // For gccgo, to communicate from the C code to the Go code.
-//go:linkname setSupportAES runtime.setSupportAES
+//go:linkname setSupportAES
 func setSupportAES(v bool) {
 	support_aes = v
 }
@@ -320,7 +319,7 @@
 func setRandomNumber(uint32)
 
 // Called by gccgo's proc.c.
-//go:linkname allocg runtime.allocg
+//go:linkname allocg
 func allocg() *g {
 	return new(g)
 }
@@ -368,17 +367,16 @@
 var usestackmaps bool
 
 // probestackmaps detects whether there are stack maps.
-//go:linkname probestackmaps runtime.probestackmaps
 func probestackmaps() bool
 
 // For the math/bits packages for gccgo.
-//go:linkname getDivideError runtime.getDivideError
+//go:linkname getDivideError
 func getDivideError() error {
 	return divideError
 }
 
 // For the math/bits packages for gccgo.
-//go:linkname getOverflowError runtime.getOverflowError
+//go:linkname getOverflowError
 func getOverflowError() error {
 	return overflowError
 }
diff --git a/libgo/go/runtime/type.go b/libgo/go/runtime/type.go
index 8af6246..1390535 100644
--- a/libgo/go/runtime/type.go
+++ b/libgo/go/runtime/type.go
@@ -179,7 +179,7 @@
 // type descriptors.
 // p points to a list of *typeDescriptorList, n is the length
 // of the list.
-//go:linkname registerTypeDescriptors runtime.registerTypeDescriptors
+//go:linkname registerTypeDescriptors
 func registerTypeDescriptors(n int, p unsafe.Pointer) {
 	*(*slice)(unsafe.Pointer(&typelist.lists)) = slice{p, n, n}
 }
diff --git a/libgo/go/runtime/utf8.go b/libgo/go/runtime/utf8.go
index 0ba0dad..6590472 100644
--- a/libgo/go/runtime/utf8.go
+++ b/libgo/go/runtime/utf8.go
@@ -6,10 +6,9 @@
 
 import _ "unsafe" // For go:linkname.
 
-// For gccgo, use go:linkname to rename compiler-called functions to
-// themselves, so that the compiler will export them.
+// For gccgo, use go:linkname to export compiler-called functions.
 //
-//go:linkname decoderune runtime.decoderune
+//go:linkname decoderune
 
 // Numbers fundamental to the encoding.
 const (