[FFmpeg-devel] [PATCH] Made appropriate changes to be able to successfully build C++ files using a Visual C++ build on Windows

[Hendrik Leppkes]

On Thu, Apr 13, 2017 at 2:16 AM, Aaron Levinson <alevinsn at aracnet.com> wrote:
> From 722cbb5f6544323430d883212ac2e38c4eb94e5f Mon Sep 17 00:00:00 2001
> From: Aaron Levinson <alevinsn at aracnet.com>
> Date: Wed, 12 Apr 2017 16:33:39 -0700
> Subject: [PATCH] Made appropriate changes to be able to successfully build C++ files using a Visual C++ build on Windows.
>
> Purpose:  Made appropriate changes to be able to
>  successfully build C++ files using a Visual C++ build on Windows.  Note that
>  this is a continuation of the "fixes w32pthreads to support C++" aspect of
>  Kyle Schwarz's "Remove pthread dependency" patch that is available at
>  https://patchwork.ffmpeg.org/patch/2654/ .  This patch wasn't accepted, and
>  as far as I can tell, there was no follow-up after it was rejected.
>
> Notes:  Used Visual Studio 2015 (with update 3) for this.
>
> Comments:
>
> -- compat/w32pthreads.h: Made appropriate changes to w32pthreads.h to
>    get it to build when it is being included in a C++ file and built
>    with Visual C++.  This is mostly a copy of Kyle Schwarz's patch as
>    described above.
>
> -- configure: Made minor modifications to MSVC (Microsoft Visual C++)
>    toolchain section to make sure that -Fo$@ is used when building
>    object files but when the C++ compiler is used and also to use cl
>    for the default C++ compiler.  This is currently only relevant for
>    building the Blackmagic/Decklink-related files under avdevice.
> ---
>  compat/w32pthreads.h | 24 ++++++++++++------------
>  configure            |  3 +++
>  2 files changed, 15 insertions(+), 12 deletions(-)
>
> diff --git a/compat/w32pthreads.h b/compat/w32pthreads.h
> index 0c9a7fa..a6c699b 100644
> --- a/compat/w32pthreads.h
> +++ b/compat/w32pthreads.h
> @@ -77,7 +77,7 @@ typedef struct pthread_cond_t {
>
>  static av_unused unsigned __stdcall attribute_align_arg win32thread_worker(void *arg)
>  {
> -    pthread_t *h = arg;
> +    pthread_t *h = (pthread_t*)arg;
>      h->ret = h->func(h->arg);
>      return 0;
>  }
> @@ -270,7 +270,7 @@ static av_unused int pthread_cond_init(pthread_cond_t *cond, const void *unused_
>      }
>
>      /* non native condition variables */
> -    win32_cond = av_mallocz(sizeof(win32_cond_t));
> +    win32_cond = (win32_cond_t*)av_mallocz(sizeof(win32_cond_t));
>      if (!win32_cond)
>          return ENOMEM;
>      cond->Ptr = win32_cond;
> @@ -288,7 +288,7 @@ static av_unused int pthread_cond_init(pthread_cond_t *cond, const void *unused_
>
>  static av_unused int pthread_cond_destroy(pthread_cond_t *cond)
>  {
> -    win32_cond_t *win32_cond = cond->Ptr;
> +    win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr;
>      /* native condition variables do not destroy */
>      if (cond_init)
>          return 0;
> @@ -305,7 +305,7 @@ static av_unused int pthread_cond_destroy(pthread_cond_t *cond)
>
>  static av_unused int pthread_cond_broadcast(pthread_cond_t *cond)
>  {
> -    win32_cond_t *win32_cond = cond->Ptr;
> +    win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr;
>      int have_waiter;
>
>      if (cond_broadcast) {
> @@ -337,7 +337,7 @@ static av_unused int pthread_cond_broadcast(pthread_cond_t *cond)
>
>  static av_unused int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
>  {
> -    win32_cond_t *win32_cond = cond->Ptr;
> +    win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr;
>      int last_waiter;
>      if (cond_wait) {
>          cond_wait(cond, mutex, INFINITE);
> @@ -369,7 +369,7 @@ static av_unused int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mu
>
>  static av_unused int pthread_cond_signal(pthread_cond_t *cond)
>  {
> -    win32_cond_t *win32_cond = cond->Ptr;
> +    win32_cond_t *win32_cond = (win32_cond_t*)cond->Ptr;
>      int have_waiter;
>      if (cond_signal) {
>          cond_signal(cond);
> @@ -400,17 +400,17 @@ static av_unused void w32thread_init(void)
>      HANDLE kernel_dll = GetModuleHandle(TEXT("kernel32.dll"));
>      /* if one is available, then they should all be available */
>      cond_init      = (void (WINAPI*)(pthread_cond_t *))
> -        GetProcAddress(kernel_dll, "InitializeConditionVariable");
> +        GetProcAddress((HMODULE)kernel_dll, "InitializeConditionVariable");
>      cond_broadcast = (void (WINAPI*)(pthread_cond_t *))
> -        GetProcAddress(kernel_dll, "WakeAllConditionVariable");
> +        GetProcAddress((HMODULE)kernel_dll, "WakeAllConditionVariable");
>      cond_signal    = (void (WINAPI*)(pthread_cond_t *))
> -        GetProcAddress(kernel_dll, "WakeConditionVariable");
> +        GetProcAddress((HMODULE)kernel_dll, "WakeConditionVariable");
>      cond_wait      = (BOOL (WINAPI*)(pthread_cond_t *, pthread_mutex_t *, DWORD))
> -        GetProcAddress(kernel_dll, "SleepConditionVariableCS");
> +        GetProcAddress((HMODULE)kernel_dll, "SleepConditionVariableCS");
>      initonce_begin = (BOOL (WINAPI*)(pthread_once_t *, DWORD, BOOL *, void **))
> -        GetProcAddress(kernel_dll, "InitOnceBeginInitialize");
> +        GetProcAddress((HMODULE)kernel_dll, "InitOnceBeginInitialize");
>      initonce_complete = (BOOL (WINAPI*)(pthread_once_t *, DWORD, void *))
> -        GetProcAddress(kernel_dll, "InitOnceComplete");
> +        GetProcAddress((HMODULE)kernel_dll, "InitOnceComplete");
>  #endif
>
>  }
> diff --git a/configure b/configure
> index d13d60b..b0f7b1a 100755
> --- a/configure
> +++ b/configure
> @@ -3635,10 +3635,13 @@ case "$toolchain" in
>          # successfully parses the version number of existing supported
>          # versions that require the converter (MSVC 2010 and 2012).
>          cl_major_ver=$(cl 2>&1 | sed -n 's/.*Version \([[:digit:]]\{1,\}\)\..*/\1/p')
> +        CXX_O='-Fo$@'
>          if [ -z "$cl_major_ver" ] || [ $cl_major_ver -ge 18 ]; then
>              cc_default="cl"
> +            cxx_default="cl"
>          else
>              cc_default="c99wrap cl"
> +            cxx_default="c99wrap cl"
>          fi
>          ld_default="$source_path/compat/windows/mslink"
>          nm_default="dumpbin -symbols"

CXX_O is in the wrong spot, it should be set at the same place where
CC_O is beint set, and not here.

- Hendrik