Share DLL code between gdb and gdbserver

This moves the new DLL-loading code into nat/windows-nat.c, and
changes both gdb and gdbserver to use the shared code.  One
client-provided callback, handle_load_dll, is changed to allow the
code to be shared.  This callback was actually never called from
nat/windows-nat.c; maybe I had planned to share more here and then
didn't finish... I'm not sure.

gdb/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* windows-nat.c (windows_nat::handle_load_dll): Update.
	(windows_nat_target::get_windows_debug_event): Call
	dll_loaded_event.
	(windows_add_all_dlls, windows_add_dll): Move to
	nat/windows-nat.c.
	* nat/windows-nat.h (handle_load_dll): Change parameters.
	(dll_loaded_event, windows_add_all_dlls): Declare.
	* nat/windows-nat.c (windows_add_dll, windows_add_all_dlls): Move
	from windows-nat.c.
	(dll_loaded_event): New function.

gdbserver/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* win32-low.cc (do_initial_child_stuff): Update.
	(windows_nat::handle_load_dll): Rename from win32_add_one_solib.
	Change parameter type.
	(win32_add_dll, win32_add_all_dlls)
	(windows_nat::handle_load_dll): Remove.
	(get_child_debug_event): Call dll_loaded_event.

1 files changed, 4 insertions, 168 deletions

diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 471d8fc..22f8b7a 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -787,38 +787,13 @@ windows_make_so (const char *name, LPVOID load_addr)
   return so;
 }
 
-static bool windows_add_dll (LPVOID);
-
 /* See nat/windows-nat.h.  */
 
 void
-windows_nat::handle_load_dll ()
+windows_nat::handle_load_dll (const char *dll_name, LPVOID base)
 {
-  LOAD_DLL_DEBUG_INFO *event = &current_event.u.LoadDll;
-  const char *dll_name;
-
-  /* Try getting the DLL name via the lpImageName field of the event.
-     Note that Microsoft documents this fields as strictly optional,
-     in the sense that it might be NULL.  And the first DLL event in
-     particular is explicitly documented as "likely not pass[ed]"
-     (source: MSDN LOAD_DLL_DEBUG_INFO structure).  */
-  dll_name = get_image_name (current_process_handle,
-			     event->lpImageName, event->fUnicode);
-  /* If the DLL name could not be gleaned via lpImageName, try harder
-     by enumerating all the DLLs loaded into the inferior, looking for
-     one that is loaded at base address = lpBaseOfDll. */
-  if (dll_name != nullptr)
-    {
-
-      solib_end->next = windows_make_so (dll_name, event->lpBaseOfDll);
-      solib_end = solib_end->next;
-    }
-  else if (event->lpBaseOfDll != nullptr
-	   && windows_add_dll (event->lpBaseOfDll))
-    dll_name = solib_end->so_name;
-
-  if (dll_name == nullptr)
-    return;
+  solib_end->next = windows_make_so (dll_name, base);
+  solib_end = solib_end->next;
 
   lm_info_windows *li = (lm_info_windows *) solib_end->lm_info;
 
@@ -1641,7 +1616,7 @@ windows_nat_target::get_windows_debug_event (int pid,
       CloseHandle (current_event.u.LoadDll.hFile);
       if (saw_create != 1 || ! windows_initialization_done)
 	break;
-      catch_errors (handle_load_dll);
+      catch_errors (dll_loaded_event);
       ourstatus->kind = TARGET_WAITKIND_LOADED;
       ourstatus->value.integer = 0;
       thread_id = current_event.dwThreadId;
@@ -1823,145 +1798,6 @@ windows_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus,
     }
 }
 
-/* Iterate over all DLLs currently mapped by our inferior, and
-   add them to our list of solibs.  */
-
-static void
-windows_add_all_dlls (void)
-{
-  windows_add_dll (NULL);
-}
-
-/* Iterate over all DLLs currently mapped by our inferior, looking for
-   a DLL which is loaded at LOAD_ADDR.  If found, add the DLL to our
-   list of solibs and return 'true'; otherwise do nothing and return
-   'false'.  LOAD_ADDR NULL means add all DLLs to the list of solibs;
-   this is used when the inferior finishes its initialization, and all
-   the DLLs it statically depends on are presumed loaded.  */
-
-static bool
-windows_add_dll (LPVOID load_addr)
-{
-  HMODULE dummy_hmodule;
-  DWORD cb_needed;
-  HMODULE *hmodules;
-  int i;
-
-#ifdef __x86_64__
-  if (wow64_process)
-    {
-      if (EnumProcessModulesEx (current_process_handle, &dummy_hmodule,
-				sizeof (HMODULE), &cb_needed,
-				LIST_MODULES_32BIT) == 0)
-	return false;
-    }
-  else
-#endif
-    {
-      if (EnumProcessModules (current_process_handle, &dummy_hmodule,
-			      sizeof (HMODULE), &cb_needed) == 0)
-	return false;
-    }
-
-  if (cb_needed < 1)
-    return false;
-
-  hmodules = (HMODULE *) alloca (cb_needed);
-#ifdef __x86_64__
-  if (wow64_process)
-    {
-      if (EnumProcessModulesEx (current_process_handle, hmodules,
-				cb_needed, &cb_needed,
-				LIST_MODULES_32BIT) == 0)
-	return false;
-    }
-  else
-#endif
-    {
-      if (EnumProcessModules (current_process_handle, hmodules,
-			      cb_needed, &cb_needed) == 0)
-	return false;
-    }
-
-  char system_dir[__PMAX];
-  char syswow_dir[__PMAX];
-  size_t system_dir_len = 0;
-  bool convert_syswow_dir = false;
-#ifdef __x86_64__
-  if (wow64_process)
-#endif
-    {
-      /* This fails on 32bit Windows because it has no SysWOW64 directory,
-	 and in this case a path conversion isn't necessary.  */
-      UINT len = GetSystemWow64DirectoryA (syswow_dir, sizeof (syswow_dir));
-      if (len > 0)
-	{
-	  /* Check that we have passed a large enough buffer.  */
-	  gdb_assert (len < sizeof (syswow_dir));
-
-	  len = GetSystemDirectoryA (system_dir, sizeof (system_dir));
-	  /* Error check.  */
-	  gdb_assert (len != 0);
-	  /* Check that we have passed a large enough buffer.  */
-	  gdb_assert (len < sizeof (system_dir));
-
-	  strcat (system_dir, "\\");
-	  strcat (syswow_dir, "\\");
-	  system_dir_len = strlen (system_dir);
-
-	  convert_syswow_dir = true;
-	}
-
-    }
-  for (i = 1; i < (int) (cb_needed / sizeof (HMODULE)); i++)
-    {
-      MODULEINFO mi;
-#ifdef __USEWIDE
-      wchar_t dll_name[__PMAX];
-      char dll_name_mb[__PMAX];
-#else
-      char dll_name[__PMAX];
-#endif
-      const char *name;
-      if (GetModuleInformation (current_process_handle, hmodules[i],
-				&mi, sizeof (mi)) == 0)
-	continue;
-
-      if (GetModuleFileNameEx (current_process_handle, hmodules[i],
-			       dll_name, sizeof (dll_name)) == 0)
-	continue;
-#ifdef __USEWIDE
-      wcstombs (dll_name_mb, dll_name, __PMAX);
-      name = dll_name_mb;
-#else
-      name = dll_name;
-#endif
-      /* Convert the DLL path of 32bit processes returned by
-	 GetModuleFileNameEx from the 64bit system directory to the
-	 32bit syswow64 directory if necessary.  */
-      std::string syswow_dll_path;
-      if (convert_syswow_dir
-	  && strncasecmp (name, system_dir, system_dir_len) == 0
-	  && strchr (name + system_dir_len, '\\') == nullptr)
-	{
-	  syswow_dll_path = syswow_dir;
-	  syswow_dll_path += name + system_dir_len;
-	  name = syswow_dll_path.c_str();
-	}
-
-      /* Record the DLL if either LOAD_ADDR is NULL or the address
-	 at which the DLL was loaded is equal to LOAD_ADDR.  */
-      if (!(load_addr != nullptr && mi.lpBaseOfDll != load_addr))
-	{
-	  solib_end->next = windows_make_so (name, mi.lpBaseOfDll);
-	  solib_end = solib_end->next;
-	  if (load_addr != nullptr)
-	    return true;
-	}
-    }
-  return load_addr == nullptr ? true : false;
-}
-
 void
 windows_nat_target::do_initial_windows_stuff (DWORD pid, bool attaching)
 {