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

1 files changed, 9 insertions, 9 deletions

diff --git a/libgo/go/runtime/netpoll.go b/libgo/go/runtime/netpoll.go
index ab3d14d..6016b7d 100644
--- a/libgo/go/runtime/netpoll.go
+++ b/libgo/go/runtime/netpoll.go
@@ -85,7 +85,7 @@ var (
 	netpollWaiters uint32
 )
 
-//go:linkname poll_runtime_pollServerInit internal_poll.runtime_pollServerInit
+//go:linkname poll_runtime_pollServerInit internal..z2fpoll.runtime_pollServerInit
 func poll_runtime_pollServerInit() {
 	netpollinit()
 	atomic.Store(&netpollInited, 1)
@@ -95,7 +95,7 @@ func netpollinited() bool {
 	return atomic.Load(&netpollInited) != 0
 }
 
-//go:linkname poll_runtime_pollServerDescriptor internal_poll.runtime_pollServerDescriptor
+//go:linkname poll_runtime_pollServerDescriptor internal..z2fpoll.runtime_pollServerDescriptor
 
 // poll_runtime_pollServerDescriptor returns the descriptor being used,
 // or ^uintptr(0) if the system does not use a poll descriptor.
@@ -103,7 +103,7 @@ func poll_runtime_pollServerDescriptor() uintptr {
 	return netpolldescriptor()
 }
 
-//go:linkname poll_runtime_pollOpen internal_poll.runtime_pollOpen
+//go:linkname poll_runtime_pollOpen internal..z2fpoll.runtime_pollOpen
 func poll_runtime_pollOpen(fd uintptr) (*pollDesc, int) {
 	pd := pollcache.alloc()
 	lock(&pd.lock)
@@ -127,7 +127,7 @@ func poll_runtime_pollOpen(fd uintptr) (*pollDesc, int) {
 	return pd, int(errno)
 }
 
-//go:linkname poll_runtime_pollClose internal_poll.runtime_pollClose
+//go:linkname poll_runtime_pollClose internal..z2fpoll.runtime_pollClose
 func poll_runtime_pollClose(pd *pollDesc) {
 	if !pd.closing {
 		throw("runtime: close polldesc w/o unblock")
@@ -149,7 +149,7 @@ func (c *pollCache) free(pd *pollDesc) {
 	unlock(&c.lock)
 }
 
-//go:linkname poll_runtime_pollReset internal_poll.runtime_pollReset
+//go:linkname poll_runtime_pollReset internal..z2fpoll.runtime_pollReset
 func poll_runtime_pollReset(pd *pollDesc, mode int) int {
 	err := netpollcheckerr(pd, int32(mode))
 	if err != 0 {
@@ -163,7 +163,7 @@ func poll_runtime_pollReset(pd *pollDesc, mode int) int {
 	return 0
 }
 
-//go:linkname poll_runtime_pollWait internal_poll.runtime_pollWait
+//go:linkname poll_runtime_pollWait internal..z2fpoll.runtime_pollWait
 func poll_runtime_pollWait(pd *pollDesc, mode int) int {
 	err := netpollcheckerr(pd, int32(mode))
 	if err != 0 {
@@ -185,7 +185,7 @@ func poll_runtime_pollWait(pd *pollDesc, mode int) int {
 	return 0
 }
 
-//go:linkname poll_runtime_pollWaitCanceled internal_poll.runtime_pollWaitCanceled
+//go:linkname poll_runtime_pollWaitCanceled internal..z2fpoll.runtime_pollWaitCanceled
 func poll_runtime_pollWaitCanceled(pd *pollDesc, mode int) {
 	// This function is used only on windows after a failed attempt to cancel
 	// a pending async IO operation. Wait for ioready, ignore closing or timeouts.
@@ -193,7 +193,7 @@ func poll_runtime_pollWaitCanceled(pd *pollDesc, mode int) {
 	}
 }
 
-//go:linkname poll_runtime_pollSetDeadline internal_poll.runtime_pollSetDeadline
+//go:linkname poll_runtime_pollSetDeadline internal..z2fpoll.runtime_pollSetDeadline
 func poll_runtime_pollSetDeadline(pd *pollDesc, d int64, mode int) {
 	lock(&pd.lock)
 	if pd.closing {
@@ -263,7 +263,7 @@ func poll_runtime_pollSetDeadline(pd *pollDesc, d int64, mode int) {
 	}
 }
 
-//go:linkname poll_runtime_pollUnblock internal_poll.runtime_pollUnblock
+//go:linkname poll_runtime_pollUnblock internal..z2fpoll.runtime_pollUnblock
 func poll_runtime_pollUnblock(pd *pollDesc) {
 	lock(&pd.lock)
 	if pd.closing {