esx: Simplify goto usage

Eliminate almost all backward jumps by replacing this common pattern:

int
some_random_function(void)
{
    int result = 0;
    ...

  cleanup:
    <unconditional cleanup code>
    return result;

  failure:
    <cleanup code in case of an error>
    result = -1;
    goto cleanup
}

with this simpler pattern:

int
some_random_function(void)
{
    int result = -1;
    ...
    result = 0;

  cleanup:
    if (result < 0) {
        <cleanup code in case of an error>
    }

    <unconditional cleanup code>
    return result;
}

Add a bool success variable in functions that don't have a int result
that can be used for the new pattern.

Also remove some unnecessary memsets in error paths.

src/esx/esx_storage_driver.c

@@ -467,10 +467,6 @@ esxStoragePoolGetInfo(virStoragePoolPtr pool, virStoragePoolInfoPtr info)
     result = 0;
 
   cleanup:
-    if (result < 0) {
-        memset(info, 0, sizeof (*info));
-    }
-
     esxVI_String_Free(&propertyNameList);
     esxVI_ObjectContent_Free(&datastore);
 

src/esx/esx_util.c

@@ -43,7 +43,7 @@ int
 esxUtil_ParseQuery(xmlURIPtr uri, char **transport, char **vCenter,
                    int *noVerify, int *autoAnswer)
 {
-    int result = 0;
+    int result = -1;
     int i;
     struct qparam_set *queryParamSet = NULL;
     struct qparam *queryParam = NULL;
@@ -71,7 +71,7 @@ esxUtil_ParseQuery(xmlURIPtr uri, char **transport, char **vCenter,
 #endif
 
     if (queryParamSet == NULL) {
-        goto failure;
+        return -1;
     }
 
     for (i = 0; i < queryParamSet->n; i++) {
@@ -86,14 +86,14 @@ esxUtil_ParseQuery(xmlURIPtr uri, char **transport, char **vCenter,
 
             if (*transport == NULL) {
                 virReportOOMError();
-                goto failure;
+                goto cleanup;
             }
 
             if (STRNEQ(*transport, "http") && STRNEQ(*transport, "https")) {
                 ESX_ERROR(VIR_ERR_INVALID_ARG,
                           _("Query parameter 'transport' has unexpected value "
                             "'%s' (should be http|https)"), *transport);
-                goto failure;
+                goto cleanup;
             }
         } else if (STRCASEEQ(queryParam->name, "vcenter")) {
             if (vCenter == NULL) {
@@ -104,7 +104,7 @@ esxUtil_ParseQuery(xmlURIPtr uri, char **transport, char **vCenter,
 
             if (*vCenter == NULL) {
                 virReportOOMError();
-                goto failure;
+                goto cleanup;
             }
         } else if (STRCASEEQ(queryParam->name, "no_verify")) {
             if (noVerify == NULL) {
@@ -116,7 +116,7 @@ esxUtil_ParseQuery(xmlURIPtr uri, char **transport, char **vCenter,
                 ESX_ERROR(VIR_ERR_INVALID_ARG,
                           _("Query parameter 'no_verify' has unexpected value "
                             "'%s' (should be 0 or 1)"), queryParam->value);
-                goto failure;
+                goto cleanup;
             }
         } else if (STRCASEEQ(queryParam->name, "auto_answer")) {
             if (autoAnswer == NULL) {
@@ -128,7 +128,7 @@ esxUtil_ParseQuery(xmlURIPtr uri, char **transport, char **vCenter,
                 ESX_ERROR(VIR_ERR_INVALID_ARG,
                           _("Query parameter 'auto_answer' has unexpected "
                             "value '%s' (should be 0 or 1)"), queryParam->value);
-                goto failure;
+                goto cleanup;
             }
         } else {
             VIR_WARN("Ignoring unexpected query parameter '%s'",
@@ -141,18 +141,14 @@ esxUtil_ParseQuery(xmlURIPtr uri, char **transport, char **vCenter,
 
         if (*transport == NULL) {
             virReportOOMError();
-            goto failure;
-        }
+            goto cleanup;
         }
-
-  cleanup:
-    if (queryParamSet != NULL) {
-        free_qparam_set(queryParamSet);
     }
 
-    return result;
+    result = 0;
 
-  failure:
+  cleanup:
+    if (result < 0) {
         if (transport != NULL) {
             VIR_FREE(*transport);
         }
@@ -160,10 +156,13 @@ esxUtil_ParseQuery(xmlURIPtr uri, char **transport, char **vCenter,
         if (vCenter != NULL) {
             VIR_FREE(*vCenter);
         }
+    }
 
-    result = -1;
+    if (queryParamSet != NULL) {
+        free_qparam_set(queryParamSet);
+    }
 
-    goto cleanup;
+    return result;
 }
 
 
@@ -196,7 +195,7 @@ esxUtil_ParseDatastoreRelatedPath(const char *datastoreRelatedPath,
                                   char **datastoreName,
                                   char **directoryName, char **fileName)
 {
-    int result = 0;
+    int result = -1;
     char *copyOfDatastoreRelatedPath = NULL;
     char *tmp = NULL;
     char *saveptr = NULL;
@@ -213,7 +212,7 @@ esxUtil_ParseDatastoreRelatedPath(const char *datastoreRelatedPath,
 
     if (esxVI_String_DeepCopyValue(&copyOfDatastoreRelatedPath,
                                    datastoreRelatedPath) < 0) {
-        goto failure;
+        goto cleanup;
     }
 
     /* Expected format: '[<datastore>] <path>' */
@@ -223,12 +222,12 @@ esxUtil_ParseDatastoreRelatedPath(const char *datastoreRelatedPath,
         ESX_ERROR(VIR_ERR_INTERNAL_ERROR,
                   _("Datastore related path '%s' doesn't have expected format "
                     "'[<datastore>] <path>'"), datastoreRelatedPath);
-        goto failure;
+        goto cleanup;
     }
 
     if (esxVI_String_DeepCopyValue(datastoreName,
                                    preliminaryDatastoreName) < 0) {
-        goto failure;
+        goto cleanup;
     }
 
     directoryAndFileName += strspn(directoryAndFileName, " ");
@@ -243,33 +242,32 @@ esxUtil_ParseDatastoreRelatedPath(const char *datastoreRelatedPath,
             ESX_ERROR(VIR_ERR_INTERNAL_ERROR,
                       _("Datastore related path '%s' doesn't reference a file"),
                       datastoreRelatedPath);
-            goto failure;
+            goto cleanup;
         }
 
         if (esxVI_String_DeepCopyValue(directoryName,
                                        directoryAndFileName) < 0 ||
             esxVI_String_DeepCopyValue(fileName, separator) < 0) {
-            goto failure;
+            goto cleanup;
         }
     } else {
         if (esxVI_String_DeepCopyValue(fileName, directoryAndFileName) < 0) {
-            goto failure;
+            goto cleanup;
         }
     }
 
-  cleanup:
-    VIR_FREE(copyOfDatastoreRelatedPath);
-
-    return result;
+    result = 0;
 
-  failure:
+  cleanup:
+    if (result < 0) {
         VIR_FREE(*datastoreName);
         VIR_FREE(*directoryName);
         VIR_FREE(*fileName);
+    }
 
-    result = -1;
+    VIR_FREE(copyOfDatastoreRelatedPath);
 
-    goto cleanup;
+    return result;
 }
 
 
@@ -282,7 +280,7 @@ esxUtil_ResolveHostname(const char *hostname,
     struct addrinfo *result = NULL;
     int errcode;
 
-    memset(&hints, 0, sizeof(struct addrinfo));
+    memset(&hints, 0, sizeof (hints));
 
     hints.ai_flags = AI_ADDRCONFIG;
     hints.ai_family = AF_INET;

src/esx/esx_vi_methods.c

@@ -74,14 +74,14 @@
 
 #define ESX_VI__METHOD__DESERIALIZE_OUTPUT__RequiredItem(_type)               \
     if (esxVI_##_type##_Deserialize(response->node, output) < 0) {            \
-        goto failure;                                                         \
+        goto cleanup;                                                         \
     }
 
 
 
 #define ESX_VI__METHOD__DESERIALIZE_OUTPUT__RequiredList(_type)               \
     if (esxVI_##_type##_DeserializeList(response->node, output) < 0) {        \
-        goto failure;                                                         \
+        goto cleanup;                                                         \
     }
 
 
@@ -89,7 +89,7 @@
 #define ESX_VI__METHOD__DESERIALIZE_OUTPUT__OptionalItem(_type)               \
     if (response->node != NULL &&                                             \
         esxVI_##_type##_Deserialize(response->node, output) < 0) {            \
-        goto failure;                                                         \
+        goto cleanup;                                                         \
     }
 
 
@@ -97,7 +97,7 @@
 #define ESX_VI__METHOD__DESERIALIZE_OUTPUT__OptionalList(_type)               \
     if (response->node != NULL &&                                             \
         esxVI_##_type##_DeserializeList(response->node, output) < 0) {        \
-        goto failure;                                                         \
+        goto cleanup;                                                         \
     }
 
 
@@ -107,7 +107,7 @@
     int                                                                       \
     esxVI_##_name _parameters                                                 \
     {                                                                         \
-        int result = 0;                                                       \
+        int result = -1;                                                      \
         const char *methodName = #_name;                                      \
         virBuffer buffer = VIR_BUFFER_INITIALIZER;                            \
         char *request = NULL;                                                 \
@@ -129,30 +129,29 @@
                                                                               \
         if (virBufferError(&buffer)) {                                        \
             virReportOOMError();                                              \
-            goto failure;                                                     \
+            goto cleanup;                                                     \
         }                                                                     \
                                                                               \
         request = virBufferContentAndReset(&buffer);                          \
                                                                               \
         if (esxVI_Context_Execute(ctx, methodName, request, &response,        \
                                   esxVI_Occurrence_##_occurrence) < 0) {      \
-            goto failure;                                                     \
+            goto cleanup;                                                     \
         }                                                                     \
                                                                               \
         ESX_VI__METHOD__DESERIALIZE_OUTPUT__##_occurrence(_output_type)       \
                                                                               \
+        result = 0;                                                           \
+                                                                              \
       cleanup:                                                                \
+        if (result < 0) {                                                     \
+            virBufferFreeAndReset(&buffer);                                   \
+        }                                                                     \
+                                                                              \
         VIR_FREE(request);                                                    \
         esxVI_Response_Free(&response);                                       \
                                                                               \
         return result;                                                        \
-                                                                              \
-      failure:                                                                \
-        virBufferFreeAndReset(&buffer);                                       \
-                                                                              \
-        result = -1;                                                          \
-                                                                              \
-        goto cleanup;                                                         \
     }
 
 
@@ -216,21 +215,21 @@
 
 #define ESX_VI__METHOD__PARAMETER__SERIALIZE(_type, _name)                    \
     if (esxVI_##_type##_Serialize(_name, #_name, &buffer) < 0) {              \
-        goto failure;                                                         \
+        goto cleanup;                                                         \
     }
 
 
 
 #define ESX_VI__METHOD__PARAMETER__SERIALIZE_LIST(_type, _name)               \
     if (esxVI_##_type##_SerializeList(_name, #_name, &buffer) < 0) {          \
-        goto failure;                                                         \
+        goto cleanup;                                                         \
     }
 
 
 
 #define ESX_VI__METHOD__PARAMETER__SERIALIZE_VALUE(_type, _name)              \
     if (esxVI_##_type##_SerializeValue(_name, #_name, &buffer) < 0) {         \
-        goto failure;                                                         \
+        goto cleanup;                                                         \
     }
 
 
@@ -243,7 +242,7 @@ int
 esxVI_RetrieveServiceContent(esxVI_Context *ctx,
                              esxVI_ServiceContent **serviceContent)
 {
-    int result = 0;
+    int result = -1;
     const char *request = ESX_VI__SOAP__REQUEST_HEADER
                             "<RetrieveServiceContent xmlns=\"urn:vim25\">"
                               "<_this xmlns=\"urn:vim25\" "
@@ -263,18 +262,15 @@ esxVI_RetrieveServiceContent(esxVI_Context *ctx,
     if (esxVI_Context_Execute(ctx, "RetrieveServiceContent", request,
                               &response, esxVI_Occurrence_RequiredItem) < 0 ||
         esxVI_ServiceContent_Deserialize(response->node, serviceContent) < 0) {
-        goto failure;
+        goto cleanup;
     }
 
+    result = 0;
+
   cleanup:
     esxVI_Response_Free(&response);
 
     return result;
-
-  failure:
-    result = -1;
-
-    goto cleanup;
 }
 
 

src/esx/esx_vi_types.c

@@ -297,7 +297,7 @@
     int                                                                       \
     esxVI_##_type##_Deserialize(xmlNodePtr node, esxVI_##_type **number)      \
     {                                                                         \
-        int result = 0;                                                       \
+        int result = -1;                                                      \
         char *string;                                                         \
         long long value;                                                      \
                                                                               \
@@ -317,35 +317,34 @@
             ESX_VI_ERROR(VIR_ERR_INTERNAL_ERROR,                              \
                          "XML node doesn't contain text, expecting an "       \
                          _xsdType" value");                                   \
-            goto failure;                                                     \
+            goto cleanup;                                                     \
         }                                                                     \
                                                                               \
         if (virStrToLong_ll(string, NULL, 10, &value) < 0) {                  \
             ESX_VI_ERROR(VIR_ERR_INTERNAL_ERROR,                              \
                          "Unknown value '%s' for "_xsdType, string);          \
-            goto failure;                                                     \
+            goto cleanup;                                                     \
         }                                                                     \
                                                                               \
         if (value < (_min) || value > (_max)) {                               \
             ESX_VI_ERROR(VIR_ERR_INTERNAL_ERROR,                              \
                          "Value '%s' is not representable as "_xsdType,       \
                          (const char *)string);                               \
-            goto failure;                                                     \
+            goto cleanup;                                                     \
         }                                                                     \
                                                                               \
         (*number)->value = value;                                             \
                                                                               \
-      cleanup:                                                                \
-        VIR_FREE(string);                                                     \
-                                                                              \
-        return result;                                                        \
+        result = 0;                                                           \
                                                                               \
-      failure:                                                                \
+      cleanup:                                                                \
+        if (result < 0) {                                                     \
             esxVI_##_type##_Free(number);                                     \
+        }                                                                     \
                                                                               \
-        result = -1;                                                          \
+        VIR_FREE(string);                                                     \
                                                                               \
-        goto cleanup;                                                         \
+        return result;                                                        \
     }
 
 
@@ -930,7 +929,7 @@ esxVI_String_AppendValueToList(esxVI_String **stringList, const char *value)
     esxVI_String *string = NULL;
 
     if (esxVI_String_Alloc(&string) < 0) {
-        goto failure;
+        return -1;
     }
 
     string->value = strdup(value);