From f80b2ce9fa3235ce0e627d54df25e3f6cc929c05 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20Storsj=C3=B6?= Date: Mon, 18 Dec 2023 10:48:28 +0200 Subject: [PATCH] gdigrab: Fix hwnd parameter issues MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Converting from an integer to HWND (which is a pointer) requires an explicit cast, otherwise Clang errors out like this: src/libavdevice/gdigrab.c:280:14: error: incompatible integer to pointer conversion assigning to 'HWND' (aka 'struct HWND__ *') from 'long' [-Wint-conversion] 280 | hwnd = strtol(name, &p, 0); | ^ ~~~~~~~~~~~~~~~~~~~ (With GCC and MSVC, this was a mere warning, but with recent Clang, this is an error.) After adding a cast, all compilers also warn something like this: src/libavdevice/gdigrab.c:280:16: warning: cast to 'HWND' (aka 'struct HWND__ *') from smaller integer type 'long' [-Wint-to-pointer-cast] 280 | hwnd = (HWND) strtol(name, &p, 0); | ^~~~~~~~~~~~~~~~~~~~~~~~~~ On Windows, long types are 32 bit, so to get a usable pointer, we need to use long long. And interpret it as unsigned long long while at it - i.e. using strtoull. Finally, right above it, the code triggered the following warning: src/libavdevice/gdigrab.c:278:15: warning: mixing declarations and code is incompatible with standards before C99 [-Wdeclaration-after-statement] 278 | char *p; | ^ Signed-off-by: Martin Storsjö --- libavdevice/gdigrab.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavdevice/gdigrab.c b/libavdevice/gdigrab.c index 41ef370f2b..b2858ecd89 100644 --- a/libavdevice/gdigrab.c +++ b/libavdevice/gdigrab.c @@ -274,10 +274,10 @@ gdigrab_read_header(AVFormatContext *s1) } else if (!strcmp(filename, "desktop")) { hwnd = NULL; } else if (!strncmp(filename, "hwnd=", 5)) { - name = filename + 5; char *p; + name = filename + 5; - hwnd = strtol(name, &p, 0); + hwnd = (HWND) strtoull(name, &p, 0); if (p == NULL || p == name || p[0] == '\0') {