block-coroutine-wrapper.py: support also basic return types

Extend the regex to cover also return type, pointers included.
This implies that the value returned by the function cannot be
a simple "int" anymore, but the custom return type.
Therefore remove poll_state->ret and instead use a per-function
custom "ret" field.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-13-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/block-gen.h

@@ -32,18 +32,15 @@
 typedef struct BdrvPollCo {
     AioContext *ctx;
     bool in_progress;
-    int ret;
     Coroutine *co; /* Keep pointer here for debugging */
 } BdrvPollCo;
 
-static inline int bdrv_poll_co(BdrvPollCo *s)
+static inline void bdrv_poll_co(BdrvPollCo *s)
 {
     assert(!qemu_in_coroutine());
 
     aio_co_enter(s->ctx, s->co);
     AIO_WAIT_WHILE(s->ctx, s->in_progress);
-
-    return s->ret;
 }
 
 #endif /* BLOCK_BLOCK_GEN_H */

scripts/block-coroutine-wrapper.py

@@ -92,15 +92,16 @@ def gen_block(self, format: str) -> str:
 
 
 # Match wrappers declared with a co_wrapper mark
-func_decl_re = re.compile(r'^int\s*co_wrapper'
+func_decl_re = re.compile(r'^(?P<return_type>[a-zA-Z][a-zA-Z0-9_]* [\*]?)'
+                          r'\s*co_wrapper'
                           r'(?P<variant>(_[a-z][a-z0-9_]*)?)\s*'
                           r'(?P<wrapper_name>[a-z][a-z0-9_]*)'
                           r'\((?P<args>[^)]*)\);$', re.MULTILINE)
 
 
 def func_decl_iter(text: str) -> Iterator:
     for m in func_decl_re.finditer(text):
-        yield FuncDecl(return_type='int',
+        yield FuncDecl(return_type=m.group('return_type'),
                        name=m.group('wrapper_name'),
                        args=m.group('args'),
                        variant=m.group('variant'))
@@ -123,7 +124,7 @@ def create_mixed_wrapper(func: FuncDecl) -> str:
     name = func.co_name
     struct_name = func.struct_name
     return f"""\
-int {func.name}({ func.gen_list('{decl}') })
+{func.return_type} {func.name}({ func.gen_list('{decl}') })
 {{
     if (qemu_in_coroutine()) {{
         return {name}({ func.gen_list('{name}') });
@@ -137,7 +138,8 @@ def create_mixed_wrapper(func: FuncDecl) -> str:
 
         s.poll_state.co = qemu_coroutine_create({name}_entry, &s);
 
-        return bdrv_poll_co(&s.poll_state);
+        bdrv_poll_co(&s.poll_state);
+        return s.ret;
     }}
 }}"""
 
@@ -149,7 +151,7 @@ def create_co_wrapper(func: FuncDecl) -> str:
     name = func.co_name
     struct_name = func.struct_name
     return f"""\
-int {func.name}({ func.gen_list('{decl}') })
+{func.return_type} {func.name}({ func.gen_list('{decl}') })
 {{
     {struct_name} s = {{
         .poll_state.ctx = {func.ctx},
@@ -161,13 +163,13 @@ def create_co_wrapper(func: FuncDecl) -> str:
 
     s.poll_state.co = qemu_coroutine_create({name}_entry, &s);
 
-    return bdrv_poll_co(&s.poll_state);
+    bdrv_poll_co(&s.poll_state);
+    return s.ret;
 }}"""
 
 
 def gen_wrapper(func: FuncDecl) -> str:
     assert not '_co_' in func.name
-    assert func.return_type == 'int'
 
     name = func.co_name
     struct_name = func.struct_name
@@ -183,14 +185,15 @@ def gen_wrapper(func: FuncDecl) -> str:
 
 typedef struct {struct_name} {{
     BdrvPollCo poll_state;
+    {func.return_type} ret;
 { func.gen_block('    {decl};') }
 }} {struct_name};
 
 static void coroutine_fn {name}_entry(void *opaque)
 {{
     {struct_name} *s = opaque;
 
-    s->poll_state.ret = {name}({ func.gen_list('s->{name}') });
+    s->ret = {name}({ func.gen_list('s->{name}') });
     s->poll_state.in_progress = false;
 
     aio_wait_kick();