Enable clang-analyzer (#2588)

Also fix a few smaller issues.

.clang-tidy

@@ -16,7 +16,8 @@ Checks: '
     -cert-env33-c,
     -cert-err33-c,
     -cert-err58-cpp,
-    -clang-analyzer-*,
+    -clang-analyzer-security.insecureAPI.strcpy,
+    -clang-analyzer-unix.BlockInCriticalSection,
     -concurrency-mt-unsafe,
     -cppcoreguidelines-avoid-c-arrays,
     -cppcoreguidelines-avoid-do-while,

src/curl.cpp

@@ -620,7 +620,7 @@ size_t S3fsCurl::UploadReadCallback(void* ptr, size_t size, size_t nmemb, void*
     ssize_t readbytes;
     ssize_t totalread;
     // read and set
-    for(totalread = 0, readbytes = 0; totalread < copysize; totalread += readbytes){
+    for(totalread = 0; totalread < copysize; totalread += readbytes){
         readbytes = pread(pCurl->partdata.fd, &(static_cast<char*>(ptr))[totalread], (copysize - totalread), pCurl->partdata.startpos + totalread);
         if(0 == readbytes){
             // eof
@@ -659,7 +659,7 @@ size_t S3fsCurl::DownloadWriteCallback(void* ptr, size_t size, size_t nmemb, voi
     ssize_t totalwrite;
 
     // write
-    for(totalwrite = 0, writebytes = 0; totalwrite < copysize; totalwrite += writebytes){
+    for(totalwrite = 0; totalwrite < copysize; totalwrite += writebytes){
         writebytes = pwrite(pCurl->partdata.fd, &(static_cast<char*>(ptr))[totalwrite], (copysize - totalwrite), pCurl->partdata.startpos + totalwrite);
         if(0 == writebytes){
             // eof?
@@ -4445,7 +4445,7 @@ int S3fsCurl::MultipartHeadRequest(const char* tpath, off_t size, headers_t& met
     curlmulti.SetSuccessCallback(S3fsCurl::CopyMultipartPostCallback);
     curlmulti.SetRetryCallback(S3fsCurl::CopyMultipartPostRetryCallback);
 
-    for(bytes_remaining = size, chunk = 0; 0 < bytes_remaining; bytes_remaining -= chunk){
+    for(bytes_remaining = size; 0 < bytes_remaining; bytes_remaining -= chunk){
         chunk = bytes_remaining > GetMultipartCopySize() ? GetMultipartCopySize() : bytes_remaining;
 
         std::ostringstream strrange;
@@ -4540,7 +4540,7 @@ int S3fsCurl::MultipartRenameRequest(const char* from, const char* to, headers_t
     curlmulti.SetSuccessCallback(S3fsCurl::CopyMultipartPostCallback);
     curlmulti.SetRetryCallback(S3fsCurl::CopyMultipartPostRetryCallback);
 
-    for(bytes_remaining = size, chunk = 0; 0 < bytes_remaining; bytes_remaining -= chunk){
+    for(bytes_remaining = size; 0 < bytes_remaining; bytes_remaining -= chunk){
         chunk = bytes_remaining > GetMultipartCopySize() ? GetMultipartCopySize() : bytes_remaining;
 
         std::ostringstream strrange;

src/fdcache_entity.cpp

@@ -535,8 +535,10 @@ int FdEntity::Open(const headers_t* pmeta, off_t size, const struct timespec& ts
 
             // make file pointer(for being same tmpfile)
             if(nullptr == (pfile = {fdopen(physical_fd, "wb"), &s3fs_fclose})){
+                int saved_errno = errno;
                 S3FS_PRN_ERR("failed to get fileno(%s). errno(%d)", cachepath.c_str(), errno);
                 close(physical_fd);
+                errno = saved_errno;
                 physical_fd = -1;
                 inode       = 0;
                 return (0 == errno ? -EIO : -errno);

src/s3fs.cpp

@@ -4388,10 +4388,9 @@ static int s3fs_check_service()
     }
 
     S3fsCurl s3fscurl;
-    int      res;
     bool     force_no_sse = false;
 
-    while(0 > (res = s3fscurl.CheckBucket(get_realpath("/").c_str(), support_compat_dir, force_no_sse))){
+    while(0 > s3fscurl.CheckBucket(get_realpath("/").c_str(), support_compat_dir, force_no_sse)){
         // get response code
         bool do_retry     = false;
         long responseCode = s3fscurl.GetLastResponseCode();