From 34489eb2af3bbb7be101bc838615cf4a4dc6828d Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <ian@gcc.gnu.org>
Date: Thu, 25 Oct 2018 22:18:08 +0000
Subject: compiler: improve name mangling for packpaths

    The current implementation of Gogo::pkgpath_for_symbol was written in
    a way that allowed two distinct package paths to map to the same
    symbol, which could cause collisions at link- time or compile-time.

    Switch to a better mangling scheme to insure that we get a unique
    packagepath symbol for each package. In the new scheme instead of having
    separate mangling schemes for identifiers and package paths, the
    main identifier mangler ("go_encode_id") now handles mangling of
    both packagepath characters and identifier characters.

    The new mangling scheme is more intrusive: "foo/bar.Baz" is mangled as
    "foo..z2fbar.Baz" instead of "foo_bar.Baz". To mitigate this, this
    patch also adds a demangling capability so that function names
    returned from runtime.CallersFrames are converted back to their
    original unmangled form.

    Changing the pkgpath_for_symbol scheme requires updating a number of
    //go:linkname directives and C "__asm__" directives to match the new
    scheme, as well as updating the 'gotest' driver (which makes
    assumptions about the correct mapping from pkgpath symbol to package
    name).

    Fixes golang/go#27534.

    Reviewed-on: https://go-review.googlesource.com/c/135455

From-SVN: r265510
---
 libgo/go/runtime/sigqueue.go | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

(limited to 'libgo/go/runtime/sigqueue.go')

diff --git a/libgo/go/runtime/sigqueue.go b/libgo/go/runtime/sigqueue.go
index cf926a9..1a29b20 100644
--- a/libgo/go/runtime/sigqueue.go
+++ b/libgo/go/runtime/sigqueue.go
@@ -117,7 +117,7 @@ Send:
 
 // Called to receive the next queued signal.
 // Must only be called from a single goroutine at a time.
-//go:linkname signal_recv os_signal.signal_recv
+//go:linkname signal_recv os..z2fsignal.signal_recv
 func signal_recv() uint32 {
 	for {
 		// Serve any signals from local copy.
@@ -161,7 +161,7 @@ func signal_recv() uint32 {
 // the signal(s) in question, and here we are just waiting to make sure
 // that all the signals have been delivered to the user channels
 // by the os/signal package.
-//go:linkname signalWaitUntilIdle os_signal.signalWaitUntilIdle
+//go:linkname signalWaitUntilIdle os..z2fsignal.signalWaitUntilIdle
 func signalWaitUntilIdle() {
 	// Although the signals we care about have been removed from
 	// sig.wanted, it is possible that another thread has received
@@ -181,7 +181,7 @@ func signalWaitUntilIdle() {
 }
 
 // Must only be called from a single goroutine at a time.
-//go:linkname signal_enable os_signal.signal_enable
+//go:linkname signal_enable os..z2fsignal.signal_enable
 func signal_enable(s uint32) {
 	if !sig.inuse {
 		// The first call to signal_enable is for us
@@ -208,7 +208,7 @@ func signal_enable(s uint32) {
 }
 
 // Must only be called from a single goroutine at a time.
-//go:linkname signal_disable os_signal.signal_disable
+//go:linkname signal_disable os..z2fsignal.signal_disable
 func signal_disable(s uint32) {
 	if s >= uint32(len(sig.wanted)*32) {
 		return
@@ -221,7 +221,7 @@ func signal_disable(s uint32) {
 }
 
 // Must only be called from a single goroutine at a time.
-//go:linkname signal_ignore os_signal.signal_ignore
+//go:linkname signal_ignore os..z2fsignal.signal_ignore
 func signal_ignore(s uint32) {
 	if s >= uint32(len(sig.wanted)*32) {
 		return
@@ -248,7 +248,7 @@ func sigInitIgnored(s uint32) {
 }
 
 // Checked by signal handlers.
-//go:linkname signal_ignored os_signal.signal_ignored
+//go:linkname signal_ignored os..z2fsignal.signal_ignored
 func signal_ignored(s uint32) bool {
 	i := atomic.Load(&sig.ignored[s/32])
 	return i&(1<<(s&31)) != 0
-- 
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