bitbake: lib/bb: set up infrastructure for shell message functions

Create a fifo under ${T} for each running task that can be used by the
task to send events back to BitBake. The purpose of this is to allow
OpenEmbedded's logging.bbclass (which provides shell function
equivalents for bb.warn(), bb.note() etc.) to have those functions
trigger the appropriate events within BitBake so that messages are shown
through the BitBake UI rather than just in the task log; to do that we
just call the python functions.

Part of the fix for [YOCTO #5275].

(Bitbake rev: bae330a1f8a59a912eca71177b3c6ba7c92a2f38)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/build.py

@@ -329,14 +329,50 @@ exit $?
     else:
         logfile = sys.stdout
 
-    bb.debug(2, "Executing shell function %s" % func)
+    def readfifo(data):
+        lines = data.split('\0')
+        for line in lines:
+            splitval = line.split(' ', 1)
+            cmd = splitval[0]
+            if len(splitval) > 1:
+                value = splitval[1]
+            else:
+                value = ''
+            if cmd == 'bbplain':
+                bb.plain(value)
+            elif cmd == 'bbnote':
+                bb.note(value)
+            elif cmd == 'bbwarn':
+                bb.warn(value)
+            elif cmd == 'bberror':
+                bb.error(value)
+            elif cmd == 'bbfatal':
+                # The caller will call exit themselves, so bb.error() is
+                # what we want here rather than bb.fatal()
+                bb.error(value)
+            elif cmd == 'bbdebug':
+                splitval = value.split(' ', 1)
+                level = int(splitval[0])
+                value = splitval[1]
+                bb.debug(level, value)
 
-    try:
-        with open(os.devnull, 'r+') as stdin:
-            bb.process.run(cmd, shell=False, stdin=stdin, log=logfile)
-    except bb.process.CmdError:
-        logfn = d.getVar('BB_LOGFILE', True)
-        raise FuncFailed(func, logfn)
+    tempdir = d.getVar('T', True)
+    fifopath = os.path.join(tempdir, 'fifo.%s' % os.getpid())
+    if os.path.exists(fifopath):
+        os.unlink(fifopath)
+    os.mkfifo(fifopath)
+    with open(fifopath, 'r+') as fifo:
+        try:
+            bb.debug(2, "Executing shell function %s" % func)
+
+            try:
+                with open(os.devnull, 'r+') as stdin:
+                    bb.process.run(cmd, shell=False, stdin=stdin, log=logfile, extrafiles=[(fifo,readfifo)])
+            except bb.process.CmdError:
+                logfn = d.getVar('BB_LOGFILE', True)
+                raise FuncFailed(func, logfn)
+        finally:
+            os.unlink(fifopath)
 
     bb.debug(2, "Shell function %s finished" % func)