tool: add undocumented option --dump-module-paths for win32

- Add an undocumented diagnostic option for Windows to show the full
  paths of all loaded modules regardless of whether or not libcurl
  initialization succeeds.

This is needed so that in the CI we can get a list of all DLL
dependencies after initialization (when they're most likely to have
finished loading) and then package them as artifacts so that a
functioning build can be downloaded. Also I imagine it may have some use
as a diagnostic for help requests.

Ref: https://github.com/curl/curl/pull/3103

Closes https://github.com/curl/curl/pull/3208

1 files changed, 16 insertions, 0 deletions

diff --git a/src/tool_main.c b/src/tool_main.c
index 6dc74d923..3089ee37f 100644
--- a/src/tool_main.c
+++ b/src/tool_main.c
@@ -38,6 +38,7 @@
 
 #include "tool_cfgable.h"
 #include "tool_convert.h"
+#include "tool_doswin.h"
 #include "tool_msgs.h"
 #include "tool_operate.h"
 #include "tool_panykey.h"
@@ -305,6 +306,21 @@ int main(int argc, char *argv[])
   /* Initialize the curl library - do not call any libcurl functions before
      this point */
   result = main_init(&global);
+
+#ifdef WIN32
+  /* Undocumented diagnostic option to list the full paths of all loaded
+     modules, regardless of whether or not initialization succeeded. */
+  if(argc == 2 && !strcmp(argv[1], "--dump-module-paths")) {
+    struct curl_slist *item, *head = GetLoadedModulePaths();
+    for(item = head; item; item = item->next) {
+      printf("%s\n", item->data);
+    }
+    curl_slist_free_all(head);
+    if(!result)
+      main_free(&global);
+  }
+  else
+#endif /* WIN32 */
   if(!result) {
     /* Start our curl operation */
     result = operate(&global, argc, argv);