Some warnings on compile

[Keitagit-kun]

I'm compiling curl 7.88.1 (+OpenSSL 3.0.8 quic, libssh2/1.10.0, LibZ 1.2.13, Ares 1.17.2, Brotli 1.0.9, zstd 1.5.4, nghttp2 1.52.0, ngtcp2/0.13.1, nghttp3/0.8.0)
cmake + compiler: mingw-w64 x86_64-7.2.0-win32-seh-rt_v5-rev1

curl version=[7.88.1]
Could NOT find LibPSL (missing: LIBPSL_LIBRARY LIBPSL_INCLUDE_DIR) 
Performing Curl Test HAVE_WIN32_WINNT
Performing Curl Test HAVE_WIN32_WINNT - Success
Found _WIN32_WINNT=0x502
LTO supported and enabled
Enabled features: SSL IPv6 unixsockets libz brotli zstd AsynchDNS Largefile alt-svc HSTS NTLM HTTP2 HTTP3 HTTPS-proxy unicode threadsafe
Enabled protocols: DICT FILE FTP FTPS GOPHER GOPHERS HTTP HTTPS IMAP IMAPS LDAP MQTT POP3 POP3S RTSP SCP SFTP SMB SMBS SMTP SMTPS TELNET TFTP
Enabled SSL backends: OpenSSL
Configuring done
Generating done

On compile (successful) there a few warnings:

Scanning dependencies of target libcurl
[  0%] Building C object lib/CMakeFiles/libcurl.dir/altsvc.c.obj
[  1%] Building C object lib/CMakeFiles/libcurl.dir/amigaos.c.obj
[  1%] Building C object lib/CMakeFiles/libcurl.dir/asyn-ares.c.obj
[  2%] Building C object lib/CMakeFiles/libcurl.dir/asyn-thread.c.obj
[  3%] Building C object lib/CMakeFiles/libcurl.dir/base64.c.obj
...
[ 94%] Building C object lib/CMakeFiles/libcurl.dir/vtls/wolfssl.c.obj
[ 95%] Building C object lib/CMakeFiles/libcurl.dir/vtls/x509asn1.c.obj
[ 95%] Building C object lib/CMakeFiles/libcurl.dir/vquic/curl_msh3.c.obj
[ 96%] Building C object lib/CMakeFiles/libcurl.dir/vquic/curl_ngtcp2.c.obj
C:\Temp\curl 7.88.1-OpenSSL3\curl-7.88.1\lib\vquic\curl_ngtcp2.c: In function 'qlog_callback':
C:\Temp\curl 7.88.1-OpenSSL3\curl-7.88.1\lib\vquic\curl_ngtcp2.c:208:43: warning: conversion to 'unsigned int' from 'size_t {aka long long unsigned int}' may alter its value [-Wconversion]
     ssize_t rc = write(ctx->qlogfd, data, datalen);
                                           ^~~~~~~
C:\Temp\curl 7.88.1-OpenSSL3\curl-7.88.1\lib\vquic\curl_ngtcp2.c: In function 'cf_process_ingress':
C:\Temp\curl 7.88.1-OpenSSL3\curl-7.88.1\lib\vquic\curl_ngtcp2.c:1775:57: warning: conversion to 'int' from 'size_t {aka long long unsigned int}' may alter its value [-Wconversion]
     while((recvd = recvfrom(ctx->q.sockfd, (char *)buf, bufsize, 0,
                                                         ^~~~~~~
C:\Temp\curl 7.88.1-OpenSSL3\curl-7.88.1\lib\vquic\curl_ngtcp2.c: In function 'cf_ngtcp2_close':
C:\Temp\curl 7.88.1-OpenSSL3\curl-7.88.1\lib\vquic\curl_ngtcp2.c:2179:42: warning: conversion to 'int' from 'ngtcp2_ssize {aka long long int}' may alter its value [-Wconversion]
       while((send(ctx->q.sockfd, buffer, rc, 0) == -1) &&
                                          ^~
C:\Temp\curl 7.88.1-OpenSSL3\curl-7.88.1\lib\vquic\curl_ngtcp2.c: In function 'cf_ngtcp2_destroy':
C:\Temp\curl 7.88.1-OpenSSL3\curl-7.88.1\lib\vquic\curl_ngtcp2.c:2193:23: warning: variable 'save' set but not used [-Wunused-but-set-variable]
   struct cf_call_data save;
                       ^~~~
[ 96%] Building C object lib/CMakeFiles/libcurl.dir/vquic/curl_quiche.c.obj
[ 97%] Building C object lib/CMakeFiles/libcurl.dir/vquic/vquic.c.obj
C:\Temp\curl 7.88.1-OpenSSL3\curl-7.88.1\lib\vquic\vquic.c: In function 'do_sendmsg':
C:\Temp\curl 7.88.1-OpenSSL3\curl-7.88.1\lib\vquic\vquic.c:170:55: warning: conversion to 'int' from 'size_t {aka long long unsigned int}' may alter its value [-Wconversion]
   while((sent = send(qctx->sockfd, (const char *)pkt, pktlen, 0)) == -1 &&
                                                       ^~~~~~
[ 98%] Building C object lib/CMakeFiles/libcurl.dir/vssh/libssh.c.obj
[ 98%] Building C object lib/CMakeFiles/libcurl.dir/vssh/libssh2.c.obj
[ 99%] Building C object lib/CMakeFiles/libcurl.dir/vssh/wolfssh.c.obj
[100%] Linking C static library libcurl.a
[100%] Built target libcurl

I'm ignoring them... but maybe it can be fixed or silensed...

[bagder]

I think this shows we need to setup an ngtcp2 CI job on Windows...

[icing]

I think this shows we need to setup an ngtcp2 CI job on Windows...

Ooof. Need to build all prerequisites there? Need some help for that, I guess.

[vszakats]

I could reproduce these with curl-for-win when using CMake (even with the default clang).
When building with gcc, there are also these extra ones in the Schannel code:

~/curl/lib/vtls/schannel.c: In function 'schannel_connect_step1':
~/curl/lib/vtls/schannel.c:1204:12: warning: conversion from 'long long unsigned int' to 'int' may change value [-Warith-conversion]
 1204 |     cur += sizeof(unsigned int);
      |            ^~~~~~
~/curl/lib/vtls/schannel.c:1210:12: warning: conversion from 'long long unsigned int' to 'int' may change value [-Warith-conversion]
 1210 |     cur += sizeof(unsigned int);
      |            ^~~~~~
~/curl/lib/vtls/schannel.c:1215:12: warning: conversion from 'long long unsigned int' to 'int' may change value [-Warith-conversion]
 1215 |     cur += sizeof(unsigned short);
      |            ^~~~~~
~/curl/lib/vtls/schannel.c:1228:22: warning: conversion from 'long long unsigned int' to 'unsigned int' may change value [-Warith-conversion]
 1228 |     *extension_len = *list_len + sizeof(unsigned int) + sizeof(unsigned short);
      |                      ^
At top level:

Build log (clang): https://ci.appveyor.com/project/curlorg/curl-for-win/builds/46332190