Avoid C-style casts (#2015)

Prefer more precise C++-style casts.

.clang-tidy

@@ -7,6 +7,7 @@ Checks: '
     -bugprone-macro-parentheses,
     -bugprone-narrowing-conversions,
     -bugprone-unhandled-self-assignment,
+    cppcoreguidelines-pro-type-cstyle-cast,
     google-*,
     -google-build-using-namespace,
     -google-readability-casting,

src/curl_multi.cpp

@@ -140,9 +140,9 @@ int S3fsMultiCurl::MultiPerform()
                     success = false;
                     S3FS_PRN_ERR("failed pthread_join - rc(%d) %s", rc, strerror(rc));
                 } else {
-                    int int_retval = (int)(intptr_t)(retval);
+                    long int_retval = reinterpret_cast<long>(retval);
                     if (int_retval && !(int_retval == -ENOENT && isMultiHead)) {
-                        S3FS_PRN_WARN("thread terminated with non-zero return code: %d", int_retval);
+                        S3FS_PRN_WARN("thread terminated with non-zero return code: %ld", int_retval);
                     }
                 }
             }
@@ -176,9 +176,9 @@ int S3fsMultiCurl::MultiPerform()
             success = false;
             S3FS_PRN_ERR("failed pthread_join - rc(%d)", rc);
         } else {
-            int int_retval = (int)(intptr_t)(retval);
+            long int_retval = reinterpret_cast<long>(retval);
             if (int_retval && !(int_retval == -ENOENT && isMultiHead)) {
-                S3FS_PRN_WARN("thread terminated with non-zero return code: %d", int_retval);
+                S3FS_PRN_WARN("thread terminated with non-zero return code: %ld", int_retval);
             }
         }
     }

src/fdcache_fdinfo.cpp

@@ -52,7 +52,7 @@ void* PseudoFdInfo::MultipartUploadThreadWorker(void* arg)
         if(pthparam){
             delete pthparam;
         }
-        return (void*)(intptr_t)(-EIO);
+        return reinterpret_cast<void*>(-EIO);
     }
     S3FS_PRN_INFO3("Upload Part Thread [tpath=%s][start=%lld][size=%lld][part=%d]", pthparam->path.c_str(), static_cast<long long>(pthparam->start), static_cast<long long>(pthparam->size), pthparam->part_num);
 
@@ -68,7 +68,7 @@ void* PseudoFdInfo::MultipartUploadThreadWorker(void* arg)
                 result = -EIO;
             }
             delete pthparam;
-            return (void*)(intptr_t)(result);
+            return reinterpret_cast<void*>(result);
         }
     }
 
@@ -81,7 +81,7 @@ void* PseudoFdInfo::MultipartUploadThreadWorker(void* arg)
             result = -EIO;
         }
         delete pthparam;
-        return (void*)(intptr_t)(result);
+        return reinterpret_cast<void*>(result);
     }
 
     // Send request and get result
@@ -103,7 +103,7 @@ void* PseudoFdInfo::MultipartUploadThreadWorker(void* arg)
     }
     delete pthparam;
 
-    return (void*)(intptr_t)(result);
+    return reinterpret_cast<void*>(result);
 }
 
 //------------------------------------------------

src/s3fs_xml.cpp

@@ -153,7 +153,7 @@ static char* get_object_name(xmlDocPtr doc, xmlNodePtr node, const char* path)
     // basepath(path) is as same as fullpath.
     if(0 == strcmp(reinterpret_cast<char*>(fullpath), path)){
         xmlFree(fullpath);
-        return (char*)c_strErrorObjectName;
+        return const_cast<char*>(c_strErrorObjectName);
     }
 
     // Make dir path and filename
@@ -172,15 +172,15 @@ static char* get_object_name(xmlDocPtr doc, xmlNodePtr node, const char* path)
     if(0 < strlen(dirpath)){
         // case of "/"
         if(0 == strcmp(mybname, "/") && 0 == strcmp(dirpath, "/")){
-            return (char*)c_strErrorObjectName;
+            return const_cast<char*>(c_strErrorObjectName);
         }
         // case of "."
         if(0 == strcmp(mybname, ".") && 0 == strcmp(dirpath, ".")){
-            return (char*)c_strErrorObjectName;
+            return const_cast<char *>(c_strErrorObjectName);
         }
         // case of ".."
         if(0 == strcmp(mybname, "..") && 0 == strcmp(dirpath, ".")){
-            return (char*)c_strErrorObjectName;
+            return const_cast<char *>(c_strErrorObjectName);
         }
         // case of "name"
         if(0 == strcmp(dirpath, ".")){
@@ -206,7 +206,7 @@ static char* get_object_name(xmlDocPtr doc, xmlNodePtr node, const char* path)
         }
     }
     // case of something wrong
-    return (char*)c_strErrorObjectName;
+    return const_cast<char*>(c_strErrorObjectName);
 }
 
 static xmlChar* get_exp_value_xml(xmlDocPtr doc, xmlXPathContextPtr ctx, const char* exp_key)

src/threadpoolman.cpp

@@ -71,7 +71,7 @@ void* ThreadPoolMan::Worker(void* arg)
 
     if(!psingleton){
         S3FS_PRN_ERR("The parameter for worker thread is invalid.");
-        return (void*)(intptr_t)(-EIO);
+        return reinterpret_cast<void*>(-EIO);
     }
     S3FS_PRN_INFO3("Start worker thread in ThreadPoolMan.");
 
@@ -102,9 +102,8 @@ void* ThreadPoolMan::Worker(void* arg)
 
         if(pparam){
             void* retval     = pparam->pfunc(pparam->args);
-            int   int_retval = (int)(intptr_t)(retval);
-            if(0 != int_retval){
-                S3FS_PRN_WARN("The instruction function returned with somthign error code(%d).", int_retval);
+            if(NULL != retval){
+                S3FS_PRN_WARN("The instruction function returned with somthign error code(%ld).", reinterpret_cast<long>(retval));
             }
             if(pparam->psem){
                 pparam->psem->post();
@@ -113,7 +112,7 @@ void* ThreadPoolMan::Worker(void* arg)
         }
     }
 
-    return (void*)(intptr_t)(0);
+    return NULL;
 }
 
 //------------------------------------------------
@@ -210,7 +209,7 @@ bool ThreadPoolMan::StopThreads()
         if(result){
             S3FS_PRN_ERR("failed pthread_join - result(%d)", result);
         }else{
-            S3FS_PRN_DBG("succeed pthread_join - return code(%d)", (int)(intptr_t)(retval));
+            S3FS_PRN_DBG("succeed pthread_join - return code(%ld)", reinterpret_cast<long>(retval));
         }
     }
     thread_list.clear();