meson: Improve NVMM CUDA detection

1. Add some comments explaining what headers and libs are expected on
   what systems
2. Only look in default incdirs if no incdir is specified
3. Require libnvbufsurface.so on Jetson when cuda-nvmm=enabled
4. Require libatomic on Jetson when cuda-nvmm=enabled

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8021>

diff --git a/subprojects/gst-plugins-bad/gst-libs/gst/cuda/meson.build b/subprojects/gst-plugins-bad/gst-libs/gst/cuda/meson.build
index 7bf0b320a19eb87d9931aee2a20e1814c707ec60..8bd6b58352d60afe9cd4dc6859c7f2daa2afae2b 100644 (file)
--- a/subprojects/gst-plugins-bad/gst-libs/gst/cuda/meson.build
+++ b/subprojects/gst-plugins-bad/gst-libs/gst/cuda/meson.build
@@ -40,8 +40,8 @@ if host_system not in ['windows', 'linux']
 endif
 
 # Linux ARM would need -latomic for std::atomic<int64_t>
-if host_system == 'linux' and host_machine.cpu_family() not in ['x86', 'x86_64']
-  libatomic_dep = cxx.find_library('atomic', required: false)
+if host_system == 'linux' and host_machine.cpu_family() in ['aarch64', 'arm']
+  libatomic_dep = cxx.find_library('atomic', required: get_option('cuda-nvmm'))
   if not libatomic_dep.found()
     subdir_done()
   endif
@@ -89,43 +89,52 @@ if host_system == 'windows'
     ])
   endif
 else
+  # We have NVMM with nvbufsurface.h on both Linux x86 and Jetson (aarch64)
   nvmm_opt = get_option('cuda-nvmm')
-  if not nvmm_opt.disabled()
+  fsmod = import('fs')
+  if nvmm_opt.allowed()
+    incdir_candidates = []
+
     nvmm_inc_opt = get_option('cuda-nvmm-include-path')
     if nvmm_inc_opt != ''
-      gstcuda_nvmm_inc = [include_directories(nvmm_inc_opt)]
+      incdir_candidates += [nvmm_inc_opt]
+    else
+      # try some other default locations
+      incdir_candidates = [
+        '/usr/src/jetson_multimedia_api/include',
+        '/opt/nvidia/deepstream/deepstream/sources/includes',
+      ]
     endif
 
-    if cc.has_header('nvbufsurface.h',
-                     include_directories: gstcuda_nvmm_inc,
-                     required: false)
-      have_nvbufsurface_h = true
-    # try some other default locations
-    elif cc.has_header('/usr/src/jetson_multimedia_api/include/nvbufsurface.h',
-                      required: false)
-      have_nvbufsurface_h = true
-      gstcuda_nvmm_inc = [include_directories('/usr/src/jetson_multimedia_api/include')]
-    elif cc.has_header('/opt/nvidia/deepstream/deepstream/sources/includes/nvbufsurface.h',
-                       required: false)
-      have_nvbufsurface_h = true
-      gstcuda_nvmm_inc = [include_directories('/opt/nvidia/deepstream/deepstream/sources/includes')]
-    endif
-    if nvmm_opt.enabled() and not have_nvbufsurface_h
+    foreach incdir: incdir_candidates
+      if fsmod.is_dir(incdir)
+        incdir = include_directories(incdir)
+        if cc.has_header('nvbufsurface.h',
+                         include_directories: incdir,
+                         required: false)
+          have_nvbufsurface_h = true
+          gstcuda_nvmm_inc = incdir
+          break
+        endif
+      endif
+    endforeach
+
+    if have_nvbufsurface_h
+      extra_args += ['-DHAVE_CUDA_NVMM']
+      # On Tegra, we also have libnvbufsurface.so, which is not present on x86
+      if host_machine.cpu_family() == 'aarch64'
+        # check if we have a tegra based system (jetson)
+        nvbuf_dep = cc.find_library('nvbufsurface', dirs: '/usr/lib/aarch64-linux-gnu/tegra/', required: nvmm_opt)
+        if nvbuf_dep.found()
+          extra_deps += [nvbuf_dep]
+          extra_args += ['-DHAVE_CUDA_NVMM_JETSON']
+        endif
+      endif
+    elif nvmm_opt.enabled()
       error('Could not find required header: "nvbufsurface.h"')
       subdir_done()
     endif
   endif
-
-  if have_nvbufsurface_h
-    extra_args += ['-DHAVE_CUDA_NVMM']
-
-    # check if we have a tegra based system (jetson)
-    nvbuf_dep = cc.find_library('nvbufsurface', dirs: '/usr/lib/aarch64-linux-gnu/tegra/', required: false)
-    if nvbuf_dep.found()
-      extra_deps += [nvbuf_dep]
-      extra_args += ['-DHAVE_CUDA_NVMM_JETSON']
-    endif
-  endif
 endif
 
 pkg_name = 'gstreamer-cuda-' + api_version