lib: drop, or replace sendf.h with curl_trc.h where possible

- replace `sendf.h` with `curl_trc.h` where it was included just for it.
- drop unused `curl_trc.h` includes.
- easy: delete obsolete comment about `send.h` include reason.

Also:
- move out `curl_trc.h` include from `sendf.h` and include it directly
  in users, where not done already. To flatten the include tree and
  to less rely on indirect includes.
- stop including `sendf.h` from other headers, replace it with forward
  declaration of `Curl_easy`, as done already elsewhere.

Verified with an all non-unity CI run.

Closes #20061

lib/altsvc.c

@@ -33,7 +33,7 @@
 #include "curl_fopen.h"
 #include "curl_get_line.h"
 #include "parsedate.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "curlx/inet_pton.h"
 #include "curlx/strparse.h"
 #include "curlx/timeval.h"

lib/asyn-ares.c

@@ -48,7 +48,7 @@
 
 #include "urldata.h"
 #include "cfilters.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "hostip.h"
 #include "url.h"
 #include "multiif.h"

lib/asyn-base.c

@@ -46,7 +46,6 @@
 
 #include "urldata.h"
 #include "asyn.h"
-#include "sendf.h"
 #include "hostip.h"
 #include "multiif.h"
 #include "select.h"

lib/asyn-thrdd.c

@@ -56,7 +56,7 @@
 
 #include "urldata.h"
 #include "cfilters.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "hostip.h"
 #include "url.h"
 #include "multiif.h"

lib/cf-socket.c

@@ -57,7 +57,7 @@
 
 #include "urldata.h"
 #include "bufq.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "if2ip.h"
 #include "cfilters.h"
 #include "cf-socket.h"

lib/cfilters.c

@@ -29,7 +29,7 @@
 #include "cfilters.h"
 #include "connect.h"
 #include "url.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "progress.h"
 #include "select.h"
 #include "curlx/strparse.h"

lib/conncache.c

@@ -30,7 +30,7 @@
 #include "cfilters.h"
 #include "progress.h"
 #include "multiif.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "cshutdn.h"
 #include "conncache.h"
 #include "curl_share.h"

lib/connect.c

@@ -51,7 +51,7 @@
 #endif
 
 #include "urldata.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "strerror.h"
 #include "cfilters.h"
 #include "connect.h"

lib/content_encoding.c

@@ -47,6 +47,7 @@
 #endif
 
 #include "sendf.h"
+#include "curl_trc.h"
 #include "http.h"
 #include "content_encoding.h"
 

lib/cookie.c

@@ -29,7 +29,7 @@
 #include "urldata.h"
 #include "cookie.h"
 #include "psl.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "slist.h"
 #include "curl_share.h"
 #include "strcase.h"

lib/cshutdn.c

@@ -31,7 +31,7 @@
 #include "progress.h"
 #include "multiif.h"
 #include "multi_ev.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "cshutdn.h"
 #include "sigpipe.h"
 #include "connect.h"

lib/curl_gssapi.c

@@ -27,7 +27,7 @@
 #ifdef HAVE_GSSAPI
 
 #include "curl_gssapi.h"
-#include "sendf.h"
+#include "curl_trc.h"
 
 #ifdef DEBUGBUILD
 #if defined(HAVE_GSSGNU) || !defined(_WIN32)

lib/curl_sasl.c

@@ -44,7 +44,7 @@
 #include "vauth/vauth.h"
 #include "cfilters.h"
 #include "curl_sasl.h"
-#include "sendf.h"
+#include "curl_trc.h"
 
 /* Supported mechanisms */
 static const struct {

lib/cw-out.c

@@ -28,6 +28,7 @@
 #include "cfilters.h"
 #include "multiif.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "transfer.h"
 #include "cw-out.h"
 #include "cw-pause.h"

lib/cw-out.h

@@ -26,7 +26,7 @@
 
 #include "curl_setup.h"
 
-#include "sendf.h"
+struct Curl_easy;
 
 /**
  * The client writer type "cw-out" that does the actual writing to

lib/cw-pause.c

@@ -28,6 +28,7 @@
 #include "bufq.h"
 #include "cfilters.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "cw-pause.h"
 
 

lib/cw-pause.h

@@ -26,7 +26,7 @@
 
 #include "curl_setup.h"
 
-#include "sendf.h"
+struct Curl_easy;
 
 /**
  * The client writer type "cw-pause" that buffers writes for

lib/dict.c

@@ -54,7 +54,7 @@
 
 #include "urldata.h"
 #include "transfer.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "escape.h"
 #include "dict.h"
 

lib/doh.c

@@ -30,7 +30,7 @@
 #include "curl_addrinfo.h"
 #include "doh.h"
 
-#include "sendf.h"
+#include "curl_trc.h"
 #include "multiif.h"
 #include "url.h"
 #include "connect.h"

lib/easy.c

@@ -58,7 +58,8 @@
 #include "multi_ev.h"
 #include "select.h"
 #include "cfilters.h"
-#include "sendf.h" /* for failf function prototype */
+#include "sendf.h"
+#include "curl_trc.h"
 #include "connect.h" /* for Curl_getconnectinfo */
 #include "slist.h"
 #include "mime.h"

lib/file.c

@@ -57,6 +57,7 @@
 #include "urldata.h"
 #include "progress.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "escape.h"
 #include "file.h"
 #include "multiif.h"

lib/formdata.c

@@ -32,7 +32,6 @@ struct Curl_easy;
 
 #include "urldata.h" /* for struct Curl_easy */
 #include "mime.h"
-#include "sendf.h"
 #include "strdup.h"
 #include "bufref.h"
 #include "curlx/fopen.h"

lib/ftp.c

@@ -42,6 +42,7 @@
 
 #include "urldata.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "if2ip.h"
 #include "hostip.h"
 #include "progress.h"

lib/gopher.c

@@ -29,6 +29,7 @@
 #include "urldata.h"
 #include "transfer.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "cfilters.h"
 #include "connect.h"
 #include "gopher.h"

lib/headers.c

@@ -26,6 +26,7 @@
 
 #include "urldata.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "headers.h"
 
 #if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_HEADERS_API)

lib/hostip.c

@@ -45,7 +45,7 @@
 #include <signal.h>
 
 #include "urldata.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "connect.h"
 #include "hostip.h"
 #include "hash.h"

lib/hostip4.c

@@ -44,7 +44,7 @@
 #endif
 
 #include "urldata.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "hostip.h"
 #include "url.h"
 

lib/hostip6.c

@@ -45,7 +45,7 @@
 
 #include "urldata.h"
 #include "cfilters.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "hostip.h"
 #include "url.h"
 #include "curlx/inet_pton.h"

lib/hsts.c

@@ -33,7 +33,6 @@
 #include "hsts.h"
 #include "curl_fopen.h"
 #include "curl_get_line.h"
-#include "sendf.h"
 #include "parsedate.h"
 #include "curl_share.h"
 #include "curlx/strparse.h"

lib/http.c

@@ -50,6 +50,7 @@
 #include "urldata.h"
 #include "transfer.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "formdata.h"
 #include "mime.h"
 #include "progress.h"

lib/http2.c

@@ -35,6 +35,7 @@
 #include "http2.h"
 #include "http.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "select.h"
 #include "curlx/base64.h"
 #include "multiif.h"

lib/http_aws_sigv4.c

@@ -32,7 +32,7 @@
 #include "http_aws_sigv4.h"
 #include "curl_sha256.h"
 #include "transfer.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "escape.h"
 #include "curlx/strparse.h"
 #include "curlx/timeval.h"

lib/http_negotiate.c

@@ -28,7 +28,7 @@
 
 #include "urldata.h"
 #include "cfilters.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "http_negotiate.h"
 #include "vauth/vauth.h"
 #include "vtls/vtls.h"

lib/http_ntlm.c

@@ -34,7 +34,7 @@
  */
 
 #include "urldata.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "strcase.h"
 #include "http_ntlm.h"
 #include "curl_ntlm_core.h"

lib/http_proxy.c

@@ -28,7 +28,7 @@
 
 #if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_PROXY)
 
-#include "sendf.h"
+#include "curl_trc.h"
 #include "http.h"
 #include "url.h"
 #include "cfilters.h"

lib/httpsrr.c

@@ -29,7 +29,7 @@
 #include "urldata.h"
 #include "httpsrr.h"
 #include "connect.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "strdup.h"
 
 static CURLcode httpsrr_decode_alpn(const uint8_t *cp, size_t len,

lib/idn.c

@@ -30,7 +30,6 @@
 
 #include "urldata.h"
 #include "idn.h"
-#include "sendf.h"
 
 #ifdef USE_LIBIDN2
 #include <idn2.h>

lib/imap.c

@@ -56,6 +56,7 @@
 #include "curlx/dynbuf.h"
 #include "urldata.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "hostip.h"
 #include "progress.h"
 #include "transfer.h"

lib/ldap.c

@@ -79,6 +79,7 @@
 #include "urldata.h"
 #include "cfilters.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "escape.h"
 #include "progress.h"
 #include "transfer.h"

lib/mime.c

@@ -29,6 +29,7 @@ struct Curl_easy;
 #include "mime.h"
 #include "urldata.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "transfer.h"
 #include "strdup.h"
 #include "curlx/fopen.h"

lib/mqtt.c

@@ -30,6 +30,7 @@
 #include "urldata.h"
 #include "transfer.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "progress.h"
 #include "mqtt.h"
 #include "select.h"

lib/multi.c

@@ -35,6 +35,7 @@
 #include "multiif.h"
 #include "multi_ev.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "curlx/timeval.h"
 #include "http.h"
 #include "select.h"

lib/openldap.c

@@ -43,6 +43,7 @@
 #include "urldata.h"
 #include "url.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "vtls/vtls.h"
 #include "transfer.h"
 #include "curl_ldap.h"

lib/pingpong.c

@@ -31,6 +31,7 @@
 #include "cfilters.h"
 #include "connect.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "select.h"
 #include "progress.h"
 #include "pingpong.h"

lib/pop3.c

@@ -57,6 +57,7 @@
 
 #include "urldata.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "hostip.h"
 #include "progress.h"
 #include "transfer.h"

lib/progress.c

@@ -25,7 +25,7 @@
 #include "curl_setup.h"
 
 #include "urldata.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "multiif.h"
 #include "progress.h"
 #include "transfer.h"

lib/rand.c

@@ -30,7 +30,7 @@
 
 #include "urldata.h"
 #include "vtls/vtls.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "curlx/timeval.h"
 #include "rand.h"
 #include "escape.h"

lib/request.c

@@ -31,6 +31,7 @@
 #include "progress.h"
 #include "request.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "transfer.h"
 #include "url.h"
 #include "curlx/strparse.h"

lib/rtsp.c

@@ -29,6 +29,7 @@
 #include "urldata.h"
 #include "transfer.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "multiif.h"
 #include "http.h"
 #include "url.h"

lib/sendf.c

@@ -36,6 +36,7 @@
 
 #include "urldata.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "transfer.h"
 #include "cfilters.h"
 #include "connect.h"

lib/sendf.h

@@ -26,8 +26,6 @@
 
 #include "curl_setup.h"
 
-#include "curl_trc.h"
-
 /**
  * Type of data that is being written to the client (application)
  * - data written can be either BODY or META data
@@ -55,6 +53,7 @@
 /* Forward declarations */
 struct Curl_creader;
 struct Curl_cwriter;
+struct Curl_easy;
 
 /**
  * Write `len` bytes at `prt` to the client. `type` indicates what

lib/setopt.c

@@ -41,7 +41,7 @@
 #include "strcase.h"
 #include "curl_share.h"
 #include "vtls/vtls.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "hostip.h"
 #include "http2.h"
 #include "setopt.h"

lib/smb.c

@@ -31,6 +31,7 @@
 #include "urldata.h"
 #include "url.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "cfilters.h"
 #include "connect.h"
 #include "progress.h"

lib/smtp.c

@@ -59,6 +59,7 @@
 
 #include "urldata.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "hostip.h"
 #include "progress.h"
 #include "transfer.h"

lib/socks.c

@@ -35,7 +35,7 @@
 
 #include "urldata.h"
 #include "bufq.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "select.h"
 #include "cfilters.h"
 #include "connect.h"

lib/socks_gssapi.c

@@ -29,7 +29,7 @@
 
 #include "curl_gssapi.h"
 #include "urldata.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "cfilters.h"
 #include "connect.h"
 #include "curlx/nonblock.h"

lib/socks_sspi.c

@@ -28,7 +28,7 @@
 #if defined(USE_WINDOWS_SSPI) && !defined(CURL_DISABLE_PROXY)
 
 #include "urldata.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "cfilters.h"
 #include "connect.h"
 #include "strerror.h"

lib/telnet.c

@@ -50,6 +50,7 @@
 #include "url.h"
 #include "transfer.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "telnet.h"
 #include "connect.h"
 #include "progress.h"

lib/tftp.c

@@ -51,6 +51,7 @@
 #include "cf-socket.h"
 #include "transfer.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "tftp.h"
 #include "progress.h"
 #include "connect.h"

lib/transfer.c

@@ -62,6 +62,7 @@
 #include "cw-out.h"
 #include "transfer.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "progress.h"
 #include "http.h"
 #include "url.h"

lib/url.c

@@ -74,7 +74,7 @@
 #include "vtls/vtls.h"
 #include "hostip.h"
 #include "transfer.h"
-#include "sendf.h"
+#include "curl_trc.h"
 #include "progress.h"
 #include "cookie.h"
 #include "strcase.h"

lib/vauth/cleartext.c

@@ -32,7 +32,6 @@
   (!defined(CURL_DISABLE_LDAP) && defined(USE_OPENLDAP))
 
 #include "vauth.h"
-#include "../sendf.h"
 
 /*
  * Curl_auth_create_plain_message()

lib/vauth/digest_sspi.c

@@ -32,7 +32,7 @@
 #include "vauth.h"
 #include "digest.h"
 #include "../curlx/multibyte.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../strdup.h"
 #include "../strcase.h"
 #include "../strerror.h"

lib/vauth/gsasl.c

@@ -29,7 +29,7 @@
 #ifdef USE_GSASL
 
 #include "vauth.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 
 #include <gsasl.h>
 

lib/vauth/krb5_gssapi.c

@@ -32,7 +32,7 @@
 #include "vauth.h"
 #include "../curl_sasl.h"
 #include "../curl_gssapi.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 
 #if defined(__GNUC__) && defined(__APPLE__)
 #pragma GCC diagnostic push

lib/vauth/krb5_sspi.c

@@ -29,7 +29,7 @@
 #if defined(USE_WINDOWS_SSPI) && defined(USE_KERBEROS5)
 
 #include "vauth.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 
 /*
  * Curl_auth_is_gssapi_supported()

lib/vauth/ntlm.c

@@ -36,7 +36,7 @@
 #define DEBUG_ME 0
 
 #include "vauth.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../curl_ntlm_core.h"
 #include "../rand.h"
 #include "../strdup.h"

lib/vauth/ntlm_sspi.c

@@ -28,7 +28,7 @@
 
 #include "vauth.h"
 #include "../curl_ntlm_core.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../strdup.h"
 
 /*

lib/vauth/spnego_gssapi.c

@@ -31,7 +31,7 @@
 #include "vauth.h"
 #include "../curlx/base64.h"
 #include "../curl_gssapi.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 
 #if defined(__GNUC__) && defined(__APPLE__)
 #pragma GCC diagnostic push

lib/vauth/spnego_sspi.c

@@ -30,7 +30,7 @@
 
 #include "vauth.h"
 #include "../curlx/base64.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../strerror.h"
 
 /*

lib/vquic/curl_ngtcp2.c

@@ -49,7 +49,7 @@
 #include "../urldata.h"
 #include "../url.h"
 #include "../uint-hash.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../rand.h"
 #include "../multiif.h"
 #include "../cfilters.h"

lib/vquic/curl_osslq.c

@@ -33,7 +33,7 @@
 #include <nghttp3/nghttp3.h>
 
 #include "../urldata.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../multiif.h"
 #include "../cfilters.h"
 #include "../cf-socket.h"

lib/vquic/curl_quiche.c

@@ -33,7 +33,7 @@
 #include "../urldata.h"
 #include "../cfilters.h"
 #include "../cf-socket.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../rand.h"
 #include "../multiif.h"
 #include "../connect.h"

lib/vquic/vquic-tls.c

@@ -45,7 +45,6 @@
 #endif
 
 #include "../urldata.h"
-#include "../curl_trc.h"
 #include "../cfilters.h"
 #include "../vtls/keylog.h"
 #include "../vtls/vtls.h"

lib/vssh/libssh.c

@@ -45,6 +45,7 @@
 
 #include "../urldata.h"
 #include "../sendf.h"
+#include "../curl_trc.h"
 #include "../hostip.h"
 #include "../progress.h"
 #include "../transfer.h"

lib/vssh/libssh2.c

@@ -44,6 +44,7 @@
 
 #include "../urldata.h"
 #include "../sendf.h"
+#include "../curl_trc.h"
 #include "../hostip.h"
 #include "../progress.h"
 #include "../transfer.h"

lib/vtls/gtls.c

@@ -41,7 +41,7 @@
 #include <nettle/sha2.h>
 
 #include "../urldata.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "keylog.h"
 #include "gtls.h"
 #include "vtls.h"

lib/vtls/mbedtls.c

@@ -60,7 +60,7 @@
 #endif
 #include "cipher_suite.h"
 #include "../urldata.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "mbedtls.h"
 #include "vtls.h"
 #include "vtls_int.h"

lib/vtls/openssl.c

@@ -44,7 +44,7 @@
 #endif
 
 #include "../urldata.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../formdata.h" /* for the boundary function */
 #include "../url.h" /* for the ssl config check function */
 #include "../curlx/inet_pton.h"

lib/vtls/rustls.c

@@ -33,7 +33,7 @@
 #include "../curlx/fopen.h"
 #include "../curlx/strerr.h"
 #include "../urldata.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "vtls.h"
 #include "vtls_int.h"
 #include "rustls.h"

lib/vtls/schannel.c

@@ -42,7 +42,7 @@
 #include "vtls.h"
 #include "vtls_int.h"
 #include "vtls_scache.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../connect.h" /* for the connect timeout */
 #include "../strdup.h"
 #include "../strerror.h"

lib/vtls/schannel_verify.c

@@ -43,7 +43,7 @@
 #include "../curlx/inet_pton.h"
 #include "vtls.h"
 #include "vtls_int.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../strerror.h"
 #include "../curlx/winapi.h"
 #include "../curlx/multibyte.h"

lib/vtls/vtls.c

@@ -59,7 +59,7 @@
 #include "rustls.h"         /* Rustls versions */
 
 #include "../slist.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../strcase.h"
 #include "../url.h"
 #include "../progress.h"

lib/vtls/wolfssl.c

@@ -54,7 +54,7 @@
 #endif
 
 #include "../urldata.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "vtls.h"
 #include "vtls_int.h"
 #include "vtls_scache.h"

lib/vtls/x509asn1.c

@@ -39,7 +39,7 @@
 
 #include "../urldata.h"
 #include "vtls.h"
-#include "../sendf.h"
+#include "../curl_trc.h"
 #include "../curlx/base64.h"
 #include "x509asn1.h"
 #include "../curlx/dynbuf.h"

lib/ws.c

@@ -33,6 +33,7 @@
 #include "curlx/base64.h"
 #include "connect.h"
 #include "sendf.h"
+#include "curl_trc.h"
 #include "multiif.h"
 #include "ws.h"
 #include "easyif.h"

tests/unit/unit1652.c

@@ -24,7 +24,7 @@
 #include "unitcheck.h"
 
 #include "urldata.h"
-#include "sendf.h"
+#include "curl_trc.h"
 
 /*
  * This test hardcodes the knowledge of the buffer size which is internal to