qapi: Use QAPI_LIST_PREPEND() where possible

Anywhere we create a list of just one item or by prepending items
(typically because order doesn't matter), we can use
QAPI_LIST_PREPEND().  But places where we must keep the list in order
by appending remain open-coded until later patches.

Note that as a side effect, this also performs a cleanup of two minor
issues in qga/commands-posix.c: the old code was performing
 new = g_malloc0(sizeof(*ret));
which 1) is confusing because you have to verify whether 'new' and
'ret' are variables with the same type, and 2) would conflict with C++
compilation (not an actual problem for this file, but makes
copy-and-paste harder).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20201113011340.463563-5-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
[Straightforward conflicts due to commit a8aa94b5f8 "qga: update
schema for guest-get-disks 'dependents' field" and commit a10b453a52
"target/mips: Move mips_cpu_add_definition() from helper.c to cpu.c"
resolved.  Commit message tweaked.]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

3 files changed, 38 insertions, 130 deletions

diff --git a/tests/test-clone-visitor.c b/tests/test-clone-visitor.c
index 5e1e8b2f5e..4944b3d857 100644
--- a/tests/test-clone-visitor.c
+++ b/tests/test-clone-visitor.c
@@ -65,16 +65,13 @@ static void test_clone_alternate(void)
 
 static void test_clone_list_union(void)
 {
-    uint8List *src, *dst;
+    uint8List *src = NULL, *dst;
     uint8List *tmp = NULL;
     int i;
 
     /* Build list in reverse */
     for (i = 10; i; i--) {
-        src = g_new0(uint8List, 1);
-        src->next = tmp;
-        src->value = i;
-        tmp = src;
+        QAPI_LIST_PREPEND(src, i);
     }
 
     dst = QAPI_CLONE(uint8List, src);
diff --git a/tests/test-qobject-output-visitor.c b/tests/test-qobject-output-visitor.c
index 1c856d9bd2..b20ab8b29b 100644
--- a/tests/test-qobject-output-visitor.c
+++ b/tests/test-qobject-output-visitor.c
@@ -223,7 +223,8 @@ static void test_visitor_out_list(TestOutputVisitorData *data,
                                   const void *unused)
 {
     const char *value_str = "list value";
-    TestStructList *p, *head = NULL;
+    TestStruct *value;
+    TestStructList *head = NULL;
     const int max_items = 10;
     bool value_bool = true;
     int value_int = 10;
@@ -233,14 +234,12 @@ static void test_visitor_out_list(TestOutputVisitorData *data,
 
     /* Build the list in reverse order... */
     for (i = 0; i < max_items; i++) {
-        p = g_malloc0(sizeof(*p));
-        p->value = g_malloc0(sizeof(*p->value));
-        p->value->integer = value_int + (max_items - i - 1);
-        p->value->boolean = value_bool;
-        p->value->string = g_strdup(value_str);
-
-        p->next = head;
-        head = p;
+        value = g_malloc0(sizeof(*value));
+        value->integer = value_int + (max_items - i - 1);
+        value->boolean = value_bool;
+        value->string = g_strdup(value_str);
+
+        QAPI_LIST_PREPEND(head, value);
     }
 
     visit_type_TestStructList(data->ov, NULL, &head, &error_abort);
@@ -270,26 +269,25 @@ static void test_visitor_out_list(TestOutputVisitorData *data,
 static void test_visitor_out_list_qapi_free(TestOutputVisitorData *data,
                                             const void *unused)
 {
-    UserDefTwoList *p, *head = NULL;
+    UserDefTwo *value;
+    UserDefTwoList *head = NULL;
     const char string[] = "foo bar";
     int i, max_count = 1024;
 
     for (i = 0; i < max_count; i++) {
-        p = g_malloc0(sizeof(*p));
-        p->value = g_malloc0(sizeof(*p->value));
-
-        p->value->string0 = g_strdup(string);
-        p->value->dict1 = g_new0(UserDefTwoDict, 1);
-        p->value->dict1->string1 = g_strdup(string);
-        p->value->dict1->dict2 = g_new0(UserDefTwoDictDict, 1);
-        p->value->dict1->dict2->userdef = g_new0(UserDefOne, 1);
-        p->value->dict1->dict2->userdef->string = g_strdup(string);
-        p->value->dict1->dict2->userdef->integer = 42;
-        p->value->dict1->dict2->string = g_strdup(string);
-        p->value->dict1->has_dict3 = false;
-
-        p->next = head;
-        head = p;
+        value = g_malloc0(sizeof(*value));
+
+        value->string0 = g_strdup(string);
+        value->dict1 = g_new0(UserDefTwoDict, 1);
+        value->dict1->string1 = g_strdup(string);
+        value->dict1->dict2 = g_new0(UserDefTwoDictDict, 1);
+        value->dict1->dict2->userdef = g_new0(UserDefOne, 1);
+        value->dict1->dict2->userdef->string = g_strdup(string);
+        value->dict1->dict2->userdef->integer = 42;
+        value->dict1->dict2->string = g_strdup(string);
+        value->dict1->has_dict3 = false;
+
+        QAPI_LIST_PREPEND(head, value);
     }
 
     qapi_free_UserDefTwoList(head);
diff --git a/tests/test-visitor-serialization.c b/tests/test-visitor-serialization.c
index 1c5a8b94ea..12275e56d8 100644
--- a/tests/test-visitor-serialization.c
+++ b/tests/test-visitor-serialization.c
@@ -351,135 +351,51 @@ static void test_primitive_lists(gconstpointer opaque)
     for (i = 0; i < 32; i++) {
         switch (pl.type) {
         case PTYPE_STRING: {
-            strList *tmp = g_new0(strList, 1);
-            tmp->value = g_strdup(pt->value.string);
-            if (pl.value.strings == NULL) {
-                pl.value.strings = tmp;
-            } else {
-                tmp->next = pl.value.strings;
-                pl.value.strings = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.strings, g_strdup(pt->value.string));
             break;
         }
         case PTYPE_INTEGER: {
-            intList *tmp = g_new0(intList, 1);
-            tmp->value = pt->value.integer;
-            if (pl.value.integers == NULL) {
-                pl.value.integers = tmp;
-            } else {
-                tmp->next = pl.value.integers;
-                pl.value.integers = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.integers, pt->value.integer);
             break;
         }
         case PTYPE_S8: {
-            int8List *tmp = g_new0(int8List, 1);
-            tmp->value = pt->value.s8;
-            if (pl.value.s8_integers == NULL) {
-                pl.value.s8_integers = tmp;
-            } else {
-                tmp->next = pl.value.s8_integers;
-                pl.value.s8_integers = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.s8_integers, pt->value.s8);
             break;
         }
         case PTYPE_S16: {
-            int16List *tmp = g_new0(int16List, 1);
-            tmp->value = pt->value.s16;
-            if (pl.value.s16_integers == NULL) {
-                pl.value.s16_integers = tmp;
-            } else {
-                tmp->next = pl.value.s16_integers;
-                pl.value.s16_integers = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.s16_integers, pt->value.s16);
             break;
         }
         case PTYPE_S32: {
-            int32List *tmp = g_new0(int32List, 1);
-            tmp->value = pt->value.s32;
-            if (pl.value.s32_integers == NULL) {
-                pl.value.s32_integers = tmp;
-            } else {
-                tmp->next = pl.value.s32_integers;
-                pl.value.s32_integers = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.s32_integers, pt->value.s32);
             break;
         }
         case PTYPE_S64: {
-            int64List *tmp = g_new0(int64List, 1);
-            tmp->value = pt->value.s64;
-            if (pl.value.s64_integers == NULL) {
-                pl.value.s64_integers = tmp;
-            } else {
-                tmp->next = pl.value.s64_integers;
-                pl.value.s64_integers = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.s64_integers, pt->value.s64);
             break;
         }
         case PTYPE_U8: {
-            uint8List *tmp = g_new0(uint8List, 1);
-            tmp->value = pt->value.u8;
-            if (pl.value.u8_integers == NULL) {
-                pl.value.u8_integers = tmp;
-            } else {
-                tmp->next = pl.value.u8_integers;
-                pl.value.u8_integers = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.u8_integers, pt->value.u8);
             break;
         }
         case PTYPE_U16: {
-            uint16List *tmp = g_new0(uint16List, 1);
-            tmp->value = pt->value.u16;
-            if (pl.value.u16_integers == NULL) {
-                pl.value.u16_integers = tmp;
-            } else {
-                tmp->next = pl.value.u16_integers;
-                pl.value.u16_integers = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.u16_integers, pt->value.u16);
             break;
         }
         case PTYPE_U32: {
-            uint32List *tmp = g_new0(uint32List, 1);
-            tmp->value = pt->value.u32;
-            if (pl.value.u32_integers == NULL) {
-                pl.value.u32_integers = tmp;
-            } else {
-                tmp->next = pl.value.u32_integers;
-                pl.value.u32_integers = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.u32_integers, pt->value.u32);
             break;
         }
         case PTYPE_U64: {
-            uint64List *tmp = g_new0(uint64List, 1);
-            tmp->value = pt->value.u64;
-            if (pl.value.u64_integers == NULL) {
-                pl.value.u64_integers = tmp;
-            } else {
-                tmp->next = pl.value.u64_integers;
-                pl.value.u64_integers = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.u64_integers, pt->value.u64);
             break;
         }
         case PTYPE_NUMBER: {
-            numberList *tmp = g_new0(numberList, 1);
-            tmp->value = pt->value.number;
-            if (pl.value.numbers == NULL) {
-                pl.value.numbers = tmp;
-            } else {
-                tmp->next = pl.value.numbers;
-                pl.value.numbers = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.numbers, pt->value.number);
             break;
         }
         case PTYPE_BOOLEAN: {
-            boolList *tmp = g_new0(boolList, 1);
-            tmp->value = pt->value.boolean;
-            if (pl.value.booleans == NULL) {
-                pl.value.booleans = tmp;
-            } else {
-                tmp->next = pl.value.booleans;
-                pl.value.booleans = tmp;
-            }
+            QAPI_LIST_PREPEND(pl.value.booleans, pt->value.boolean);
             break;
         }
         default:
@@ -704,10 +620,7 @@ static void test_nested_struct_list(gconstpointer opaque)
     int i = 0;
 
     for (i = 0; i < 8; i++) {
-        tmp = g_new0(UserDefTwoList, 1);
-        tmp->value = nested_struct_create();
-        tmp->next = listp;
-        listp = tmp;
+        QAPI_LIST_PREPEND(listp, nested_struct_create());
     }
 
     ops->serialize(listp, &serialize_data, visit_nested_struct_list,