CI: build examples for additional code verification

Some CIs already build them, let's do it on more of them.

Ignore -Wformat while using GCC on mingw to compile examples.
Improve size_t to long conversion in imap-append.c example.

Ref: curl#6079
Ref: curl#6082
Assisted-by: Jay Satiro

Follow up to curl#7690
Replaces curl#7591
Closes curl#7922

.azure-pipelines.yml

@@ -83,7 +83,7 @@ stages:
     - script: ./buildconf && ./configure --enable-warnings --enable-werror $(configure)
       displayName: 'configure $(name)'
 
-    - script: make V=1 && cd tests && make V=1
+    - script: make V=1 && make V=1 examples && cd tests && make V=1
       displayName: 'compile'
       env:
         MAKEFLAGS: "-j 2"
@@ -191,7 +191,7 @@ stages:
     - script: $(container_cmd) -l -c "cd $(echo '%cd%') && ./buildconf && ./configure $(configure)"
       displayName: 'configure $(name)'
 
-    - script: $(container_cmd) -l -c "cd $(echo '%cd%') && make V=1 && cd tests && make V=1"
+    - script: $(container_cmd) -l -c "cd $(echo '%cd%') && make V=1 && make V=1 examples && cd tests && make V=1"
       displayName: 'compile'
       env:
         MAKEFLAGS: "-j 2"

.circleci/config.yml

@@ -34,6 +34,7 @@ commands:
   build:
     steps:
       - run: make V=1
+      - run: make V=1 examples
 
   test:
     steps:

.cirrus.yml

@@ -57,7 +57,7 @@ freebsd_task:
     #  esac
     - ./configure --prefix="${HOME}"/install --enable-debug --with-openssl --with-libssh2 --with-brotli --with-gssapi --with-libidn2 --enable-manual --enable-ldap --enable-ldaps --with-librtmp --with-libpsl --with-nghttp2 || { tail -300 config.log; false; }
   compile_script:
-    - make V=1 && cd tests && make V=1
+    - make V=1 && make V=1 examples && cd tests && make V=1
   test_script:
     # blackhole?
     - sysctl net.inet.tcp.blackhole
@@ -122,7 +122,7 @@ windows_task:
   configure_script: |
     %container_cmd% -l -c "cd $(echo '%cd%') && ./buildconf && ./configure %configure%"
   compile_script: |
-    %container_cmd% -l -c "cd $(echo '%cd%') && make V=1 && cd tests && make V=1"
+    %container_cmd% -l -c "cd $(echo '%cd%') && make V=1 && make V=1 examples && cd tests && make V=1"
   install_script: |
     %container_cmd% -l -c "cd $(echo '%cd%') && make V=1 install && PATH=/usr/bin:/bin find . -type f -path '*/.libs/*.exe' -print -execdir mv -t .. {} \;"
   test_script: |

docs/examples/anyauthput.c

@@ -31,6 +31,11 @@
 
 #include <curl/curl.h>
 
+#if defined(__GNUC__) && defined(__MINGW32__)
+/* GCC 10 on mingw has issues with this, disable */
+#pragma GCC diagnostic ignored "-Wformat"
+#endif
+
 #ifdef WIN32
 #  include <io.h>
 #  define READ_3RD_ARG unsigned int

docs/examples/chkspeed.c

@@ -40,6 +40,11 @@
 
 #include <curl/curl.h>
 
+#if defined(__GNUC__) && defined(__MINGW32__)
+/* GCC 10 on mingw has issues with this, disable */
+#pragma GCC diagnostic ignored "-Wformat"
+#endif
+
 #define URL_BASE "http://speedtest.your.domain/"
 #define URL_1M   URL_BASE "file_1M.bin"
 #define URL_2M   URL_BASE "file_2M.bin"

docs/examples/fileupload.c

@@ -28,6 +28,11 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+#if defined(__GNUC__) && defined(__MINGW32__)
+/* GCC 10 on mingw has issues with this, disable */
+#pragma GCC diagnostic ignored "-Wformat"
+#endif
+
 int main(void)
 {
   CURL *curl;

docs/examples/ftpupload.c

@@ -33,6 +33,11 @@
 #include <unistd.h>
 #endif
 
+#if defined(__GNUC__) && defined(__MINGW32__)
+/* GCC 10 on mingw has issues with this, disable */
+#pragma GCC diagnostic ignored "-Wformat"
+#endif
+
 /* <DESC>
  * Performs an FTP upload and renames the file just after a successful
  * transfer.

docs/examples/httpput.c

@@ -28,6 +28,11 @@
 #include <sys/stat.h>
 #include <curl/curl.h>
 
+#if defined(__GNUC__) && defined(__MINGW32__)
+/* GCC 10 on mingw has issues with this, disable */
+#pragma GCC diagnostic ignored "-Wformat"
+#endif
+
 /*
  * This example shows a HTTP PUT operation. PUTs a file given as a command
  * line argument to the URL also given on the command line.

docs/examples/imap-append.c

@@ -89,7 +89,8 @@ int main(void)
 
   curl = curl_easy_init();
   if(curl) {
-    long infilesize;
+    size_t filesize;
+    long infilesize = LONG_MAX;
     struct upload_status upload_ctx = { 0 };
 
     /* Set username and password */
@@ -108,7 +109,9 @@ int main(void)
     curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx);
     curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
 
-    infilesize = strlen(payload_text);
+    filesize = strlen(payload_text);
+    if(filesize <= LONG_MAX)
+      infilesize = (long)filesize;
     curl_easy_setopt(curl, CURLOPT_INFILESIZE, infilesize);
 
     /* Perform the append */

docs/examples/progressfunc.c

@@ -27,6 +27,11 @@
 #include <stdio.h>
 #include <curl/curl.h>
 
+#if defined(__GNUC__) && defined(__MINGW32__)
+/* GCC 10 on mingw has issues with this, disable */
+#pragma GCC diagnostic ignored "-Wformat"
+#endif
+
 #if LIBCURL_VERSION_NUM >= 0x073d00
 /* In libcurl 7.61.0, support was added for extracting the time in plain
    microseconds. Older libcurl versions are stuck in using 'double' for this

docs/examples/sendrecv.c

@@ -28,6 +28,11 @@
 #include <string.h>
 #include <curl/curl.h>
 
+#if defined(__GNUC__) && defined(__MINGW32__)
+/* GCC 10 on mingw has issues with this, disable */
+#pragma GCC diagnostic ignored "-Wformat"
+#endif
+
 /* Auxiliary function that waits on the socket. */
 static int wait_on_socket(curl_socket_t sockfd, int for_recv, long timeout_ms)
 {

docs/examples/sftpuploadresume.c

@@ -28,6 +28,11 @@
 #include <stdio.h>
 #include <curl/curl.h>
 
+#if defined(__GNUC__) && defined(__MINGW32__)
+/* GCC 10 on mingw has issues with this, disable */
+#pragma GCC diagnostic ignored "-Wformat"
+#endif
+
 /* read data to upload */
 static size_t readfunc(char *ptr, size_t size, size_t nmemb, void *stream)
 {