utils/genrandconfig: switch to async/await format

This requires python 3.5 or newer but is a bit cleaner than the
previous coroutine method.

This should also fix a python3.12 issue:
[Tue, 28 May 2024 13:09:05] INFO: generate the configuration
Traceback (most recent call last):
  File "/home/autobuild/autobuild/instance-0/buildroot/utils/genrandconfig", line 833, in <module>
    ret = asyncio.run(gen_config(args))
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/asyncio/runners.py", line 194, in run
    return runner.run(main)
           ^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/asyncio/runners.py", line 89, in run
    raise ValueError("a coroutine was expected, got {!r}".format(coro))
ValueError: a coroutine was expected, got <generator object gen_config at 0xffff7bd822c0>
[Tue, 28 May 2024 13:09:06] WARN: failed to generate configuration

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Reviewed-by: Vincent Fazio <vfazio@xes-inc.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 584ebdea6e)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

utils/genrandconfig

@@ -28,11 +28,6 @@ import traceback
 from distutils.version import StrictVersion
 import platform
 
-if sys.version_info < (3, 8):
-    from asyncio import coroutine
-else:
-    from types import coroutine
-
 
 class SystemInfo:
     DEFAULT_NEEDED_PROGS = ["make", "git", "gcc", "timeout"]
@@ -60,8 +55,7 @@ class SystemInfo:
         # --
         return None
 
-    @coroutine
+    async def has(self, prog):
-    def has(self, prog):
         """Checks whether a program is available.
         Lazily evaluates missing entries.
 
@@ -76,11 +70,11 @@ class SystemInfo:
         have_it = self.find_prog(prog)
         # java[c] needs special care
         if have_it and prog in ('java', 'javac'):
-            proc = yield from asyncio.create_subprocess_shell(
+            proc = await asyncio.create_subprocess_shell(
                 "%s -version | grep gcj" % prog,
                 stdout=asyncio.subprocess.DEVNULL,
                 stderr=asyncio.subprocess.DEVNULL)
-            ret = yield from proc.wait()
+            ret = await proc.wait()
             if ret != 1:
                 have_it = False
         # --
@@ -159,8 +153,7 @@ def get_toolchain_configs(toolchains_csv, buildrootdir):
     return configs
 
 
-@coroutine
+async def is_toolchain_usable(configfile, config):
-def is_toolchain_usable(configfile, config):
     """Check if the toolchain is actually usable."""
 
     with open(configfile) as configf:
@@ -180,9 +173,9 @@ def is_toolchain_usable(configfile, config):
            'BR2_TOOLCHAIN_EXTERNAL_LINARO_AARCH64=y\n' in configlines or \
            'BR2_TOOLCHAIN_EXTERNAL_LINARO_AARCH64_BE=y\n' in configlines or \
            'BR2_TOOLCHAIN_EXTERNAL_LINARO_ARMEB=y\n' in configlines:
-            proc = yield from asyncio.create_subprocess_exec(
+            proc = await asyncio.create_subprocess_exec(
                 'ldd', '--version', stdout=asyncio.subprocess.PIPE)
-            ldd_version_output, _ = yield from proc.communicate()
+            ldd_version_output, _ = await proc.communicate()
             if proc.returncode:
                 return False
             glibc_version = ldd_version_output.decode().splitlines()[0].split()[-1]
@@ -193,8 +186,7 @@ def is_toolchain_usable(configfile, config):
     return True
 
 
-@coroutine
+async def fixup_config(sysinfo, configfile):
-def fixup_config(sysinfo, configfile):
     """Finalize the configuration and reject any problematic combinations
 
     This function returns 'True' when the configuration has been
@@ -210,8 +202,7 @@ def fixup_config(sysinfo, configfile):
 
     BR2_TOOLCHAIN_EXTERNAL_URL = 'BR2_TOOLCHAIN_EXTERNAL_URL="http://autobuild.buildroot.org/toolchains/tarballs/'
 
-    has_java = yield from sysinfo.has("java")
+    if "BR2_NEEDS_HOST_JAVA=y\n" in configlines and not await sysinfo.has("java"):
-    if "BR2_NEEDS_HOST_JAVA=y\n" in configlines and not has_java:
         return False
     # The ctng toolchain is affected by PR58854
     if 'BR2_PACKAGE_LTTNG_TOOLS=y\n' in configlines and \
@@ -681,8 +672,7 @@ def fixup_config(sysinfo, configfile):
     return True
 
 
-@coroutine
+async def gen_config(args):
-def gen_config(args):
     """Generate a new random configuration
 
     This function generates the configuration, by choosing a random
@@ -740,8 +730,7 @@ def gen_config(args):
 
     # Randomly enable BR2_REPRODUCIBLE 10% of times
     # also enable tar filesystem images for testing
-    has_diffoscope = yield from sysinfo.has("diffoscope")
+    if await sysinfo.has("diffoscope") and randint(0, 10) == 0:
-    if has_diffoscope and randint(0, 10) == 0:
         configlines.append("BR2_REPRODUCIBLE=y\n")
         configlines.append("BR2_TARGET_ROOTFS_TAR=y\n")
 
@@ -755,14 +744,13 @@ def gen_config(args):
     with open(configfile, "w+") as configf:
         configf.writelines(configlines)
 
-    proc = yield from asyncio.create_subprocess_exec(
+    proc = await asyncio.create_subprocess_exec(
         "make", "O=%s" % args.outputdir, "-C", args.buildrootdir, "olddefconfig")
-    ret = yield from proc.wait()
+    ret = await proc.wait()
     if ret:
         return ret
 
-    toolchain_usable = yield from is_toolchain_usable(configfile, toolchainconfig)
+    if not await is_toolchain_usable(configfile, toolchainconfig):
-    if not toolchain_usable:
         return 2
 
     # Now, generate the random selection of packages, and fixup
@@ -776,37 +764,33 @@ def gen_config(args):
                   file=sys.stderr)
             return 1
         bounded_loop -= 1
-        make_rand = [
+        proc = await asyncio.create_subprocess_exec(
             "make", "O=%s" % args.outputdir, "-C", args.buildrootdir,
             "KCONFIG_SEED=0x%s" % hexlify(os.urandom(4)).decode("ascii").upper(),
             "KCONFIG_PROBABILITY=%d" % randint(1, 20),
-            "randpackageconfig" if args.toolchains_csv else "randconfig"
+            "randpackageconfig" if args.toolchains_csv else "randconfig")
-        ]
+        ret = await proc.wait()
-        proc = yield from asyncio.create_subprocess_exec(*make_rand)
-        ret = yield from proc.wait()
         if ret:
             return ret
 
-        ret = yield from fixup_config(sysinfo, configfile)
+        if await fixup_config(sysinfo, configfile):
-        if ret:
             break
 
-    proc = yield from asyncio.create_subprocess_exec(
+    proc = await asyncio.create_subprocess_exec(
         "make", "O=%s" % args.outputdir, "-C", args.buildrootdir, "olddefconfig")
-    ret = yield from proc.wait()
+    ret = await proc.wait()
     if ret:
         return ret
 
-    proc = yield from asyncio.create_subprocess_exec(
+    proc = await asyncio.create_subprocess_exec(
         "make", "O=%s" % args.outputdir, "-C", args.buildrootdir, "savedefconfig")
-    ret = yield from proc.wait()
+    ret = await proc.wait()
     if ret:
         return ret
 
-    proc = yield from asyncio.create_subprocess_exec(
+    proc = await asyncio.create_subprocess_exec(
         "make", "O=%s" % args.outputdir, "-C", args.buildrootdir, "dependencies")
-    ret = yield from proc.wait()
+    return await proc.wait()
-    return ret
 
 
 if __name__ == '__main__':