ac/llvm: export ac_init_llvm_once in targets

If a program like mpv uses both radeon_dri.so (because --vo=gpu) and
radeonsi_drv_video.so (because --hwdec=vaapi) then LLVM will be inialized twice.

The commit exports the ac_init_llvm_once so there's only one instance of the
function.

See also 18b12bf533 ("targets: export radeon winsys_create functions to silence LLVM warning")
which implemented this workaround initially.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/1377
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Acked-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5648>

src/amd/llvm/ac_llvm_util.c

@@ -78,10 +78,9 @@ static void ac_init_llvm_target()
 	LLVMParseCommandLineOptions(ARRAY_SIZE(argv), argv, NULL);
 }
 
-static once_flag ac_init_llvm_target_once_flag = ONCE_FLAG_INIT;
-
-void ac_init_llvm_once(void)
+PUBLIC void ac_init_llvm_once(void)
 {
+	static once_flag ac_init_llvm_target_once_flag = ONCE_FLAG_INIT;
 	call_once(&ac_init_llvm_target_once_flag, ac_init_llvm_target);
 }
 

src/amd/vulkan/meson.build

@@ -176,6 +176,7 @@ if with_symbols_check
     args : [
       '--lib', libvulkan_radeon,
       '--symbols-file', vulkan_icd_symbols,
+      '--ignore-symbol', 'ac_init_llvm_once',
       symbols_check_args,
     ],
     suite : ['amd'],

src/gallium/targets/dri-vdpau.dyn

@@ -2,4 +2,5 @@
 	nouveau_drm_screen_create;
 	radeon_drm_winsys_create;
 	amdgpu_winsys_create;
+	ac_init_llvm_once;
 };

src/gallium/targets/dri/dri.sym

@@ -6,6 +6,7 @@
 		radeon_drm_winsys_create;
 		amdgpu_winsys_create;
 		fd_drm_screen_create;
+		ac_init_llvm_once;
 	local:
 		*;
 };

src/gallium/targets/omx/omx.sym

@@ -7,6 +7,7 @@
 		# due to LLVM being initialized multiple times.
 		radeon_drm_winsys_create;
 		amdgpu_winsys_create;
+		ac_init_llvm_once;
 	local:
 		*;
 };

src/gallium/targets/pipe-loader/pipe.sym

@@ -7,6 +7,7 @@
 		# due to LLVM being initialized multiple times.
 		radeon_drm_winsys_create;
 		amdgpu_winsys_create;
+		ac_init_llvm_once;
 	local:
 		*;
 };

src/gallium/targets/va/va.sym

@@ -6,6 +6,7 @@
 		# due to LLVM being initialized multiple times.
 		radeon_drm_winsys_create;
 		amdgpu_winsys_create;
+		ac_init_llvm_once;
 	local:
 		*;
 };

src/gallium/targets/vdpau/vdpau.sym

@@ -4,6 +4,7 @@
                nouveau_drm_screen_create;
                radeon_drm_winsys_create;
                amdgpu_winsys_create;
+               ac_init_llvm_once;
        local:
                *;
 };