scripts/nsis.py: Run dependency check for each DLL file only once

Each DLL should only be checked once for dependencies, but
several hundred (781 in my test) unneeded checks were done.

Now the script is significantly faster (16 s in my build).

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20250111215244.1680931-1-sw@weilnetz.de>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20250116160306.1709518-38-alex.bennee@linaro.org>

scripts/nsis.py

@@ -37,10 +37,10 @@ def find_deps(exe_or_dll, search_path, analyzed_deps):
 
         analyzed_deps.add(dep)
         # locate the dll dependencies recursively
-        rdeps = find_deps(dll, search_path, analyzed_deps)
+        analyzed_deps, rdeps = find_deps(dll, search_path, analyzed_deps)
         deps.extend(rdeps)
 
-    return deps
+    return analyzed_deps, deps
 
 def main():
     parser = argparse.ArgumentParser(description="QEMU NSIS build helper.")
@@ -92,18 +92,18 @@ def main():
         dlldir = os.path.join(destdir + prefix, "dll")
         os.mkdir(dlldir)
 
+        analyzed_deps = set()
         for exe in glob.glob(os.path.join(destdir + prefix, "*.exe")):
             signcode(exe)
 
             # find all dll dependencies
-            deps = set(find_deps(exe, search_path, set()))
+            analyzed_deps, deps = find_deps(exe, search_path, analyzed_deps)
+            deps = set(deps)
             deps.remove(exe)
 
             # copy all dlls to the DLLDIR
             for dep in deps:
                 dllfile = os.path.join(dlldir, os.path.basename(dep))
-                if (os.path.exists(dllfile)):
-                    continue
                 print("Copying '%s' to '%s'" % (dep, dllfile))
                 shutil.copy(dep, dllfile)