CL: Load OpenCL without search path modification

src/libANGLE/renderer/cl/CLPlatformCL.cpp

@@ -16,6 +16,7 @@
 
 #include "anglebase/no_destructor.h"
 #include "common/angle_version.h"
+#include "common/system_utils.h"
 
 extern "C" {
 #include "icd.h"
@@ -391,16 +392,27 @@ void CLPlatformCL::Initialize(const cl_icd_dispatch &dispatch, bool isIcd)
         return;
     }
 
+    // The absolute path to ANGLE's OpenCL library is needed and it is assumed here that
+    // it is in the same directory as the shared library which contains this CL back end.
+    std::string libPath = angle::GetModuleDirectory();
+    if (!libPath.empty() && libPath.back() != angle::GetPathSeparator())
+    {
+        libPath += angle::GetPathSeparator();
+    }
+    libPath += ANGLE_OPENCL_LIB_NAME;
+    libPath += '.';
+    libPath += angle::GetSharedLibraryExtension();
+
     // Our OpenCL entry points are not reentrant, so we have to prevent khrIcdInitialize()
     // from querying ANGLE's OpenCL library. We store a dummy entry with the library in the
     // khrIcdVendors list, because the ICD Loader skips the libraries which are already in
     // the list as it assumes they were already enumerated.
     static angle::base::NoDestructor<KHRicdVendor> sVendorAngle({});
-    sVendorAngle->library = khrIcdOsLibraryLoad(ANGLE_OPENCL_LIB_NAME);
+    sVendorAngle->library = khrIcdOsLibraryLoad(libPath.c_str());
     khrIcdVendors         = sVendorAngle.get();
     if (khrIcdVendors->library == nullptr)
     {
-        WARN() << "Unable to load library \"" ANGLE_OPENCL_LIB_NAME "\"";
+        WARN() << "Unable to load library \"" << libPath << "\"";
         return;
     }
 

src/libOpenCL/BUILD.gn

@@ -9,17 +9,25 @@ import("../../gni/angle.gni")
 assert(angle_enable_cl)
 
 cl_library_name = "OpenCL_ANGLE"
+if (is_win || is_linux) {
+  glesv2_path =
+      rebase_path(get_label_info("$angle_root:libGLESv2", "root_out_dir"))
+}
 
 config("opencl_library_name") {
   if (is_win) {
     defines = [ "ANGLE_OPENCL_LIB_NAME=\"" + cl_library_name + "\"" ]
   } else {
-    defines = [ "ANGLE_OPENCL_LIB_NAME=\"lib" + cl_library_name + ".so\"" ]
+    defines = [ "ANGLE_OPENCL_LIB_NAME=\"lib" + cl_library_name + "\"" ]
   }
 }
 
 angle_shared_library(cl_library_name) {
   defines = [ "LIBCL_IMPLEMENTATION" ]
+  if (is_win) {
+    defines += [ "ANGLE_GLESV2_LIBRARY_PATH=\"" +
+                 string_replace(glesv2_path, "/", "\\\\") + "\"" ]
+  }
 
   sources = [
     "dispatch.cpp",
@@ -39,8 +47,11 @@ angle_shared_library(cl_library_name) {
 
   if (is_linux) {
     inputs = [ "libOpenCL_autogen.map" ]
-    ldflags = [ "-Wl,--version-script=" +
-                rebase_path("libOpenCL_autogen.map", root_build_dir) ]
+    ldflags = [
+      "-Wl,--version-script=" +
+          rebase_path("libOpenCL_autogen.map", root_build_dir),
+      "-Wl,-rpath=" + glesv2_path,
+    ]
   }
 }
 

src/libOpenCL/dispatch.cpp

@@ -8,11 +8,15 @@
 #include "libOpenCL/dispatch.h"
 
 #include "anglebase/no_destructor.h"
+#include "common/debug.h"
 #include "common/system_utils.h"
 
-#include <iostream>
 #include <memory>
 
+#ifdef _WIN32
+#    include <windows.h>
+#endif
+
 namespace cl
 {
 
@@ -27,30 +31,69 @@ std::unique_ptr<angle::Library> &EntryPointsLib()
 
 IcdDispatch CreateDispatch()
 {
-    IcdDispatch dispatch;
+    const cl_icd_dispatch *clIcdDispatch = nullptr;
+    const char *error                    = nullptr;
 
+    // Try to find ANGLE's GLESv2 library in the consistent way, which might fail
+    // if the current library or a link to it is not in ANGLE's binary directory
     EntryPointsLib().reset(
         angle::OpenSharedLibrary(ANGLE_GLESV2_LIBRARY_NAME, angle::SearchType::ApplicationDir));
-    if (EntryPointsLib())
+    if (EntryPointsLib() && EntryPointsLib()->getNative() != nullptr)
     {
-        auto clIcdDispatch = reinterpret_cast<const cl_icd_dispatch *>(
-            EntryPointsLib()->getSymbol("gCLIcdDispatchTable"));
-        if (clIcdDispatch != nullptr)
-        {
-            static_cast<cl_icd_dispatch &>(dispatch) = *clIcdDispatch;
-            dispatch.clIcdGetPlatformIDsKHR          = reinterpret_cast<clIcdGetPlatformIDsKHR_fn>(
-                clIcdDispatch->clGetExtensionFunctionAddress("clIcdGetPlatformIDsKHR"));
-        }
-        else
+        EntryPointsLib()->getAs("gCLIcdDispatchTable", &clIcdDispatch);
+        if (clIcdDispatch == nullptr)
         {
-            std::cerr << "Error loading CL dispatch table." << std::endl;
+            INFO() << "Found system's instead of ANGLE's GLESv2 library";
         }
     }
     else
     {
-        std::cerr << "Error opening GLESv2 library." << std::endl;
+        error = "Not able to find GLESv2 library";
+    }
+
+    // If not found try to find ANGLE's GLESv2 library in build path
+    if (clIcdDispatch == nullptr)
+    {
+#ifdef _WIN32
+        // On Windows the build path 'ANGLE_GLESV2_LIBRARY_PATH' is provided by the build system
+        const char path[] = ANGLE_GLESV2_LIBRARY_PATH "\\" ANGLE_GLESV2_LIBRARY_NAME ".dll";
+        // This function allows to load further dependent libraries from the same directory
+        HMODULE handle = LoadLibraryExA(path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);
+        if (handle != nullptr)
+        {
+            clIcdDispatch = reinterpret_cast<const cl_icd_dispatch *>(
+                GetProcAddress(handle, "gCLIcdDispatchTable"));
+            if (clIcdDispatch == nullptr)
+            {
+                error = "Error loading CL dispatch table.";
+            }
+        }
+#else
+        // On posix-compatible systems this will also search in the rpath, which is the build path
+        EntryPointsLib().reset(
+            angle::OpenSharedLibrary(ANGLE_GLESV2_LIBRARY_NAME, angle::SearchType::SystemDir));
+        if (EntryPointsLib() && EntryPointsLib()->getNative() != nullptr)
+        {
+            EntryPointsLib()->getAs("gCLIcdDispatchTable", &clIcdDispatch);
+            if (clIcdDispatch == nullptr)
+            {
+                INFO() << "Found system's instead of ANGLE's GLESv2 library";
+            }
+        }
+#endif
     }
 
+    IcdDispatch dispatch;
+    if (clIcdDispatch != nullptr)
+    {
+        static_cast<cl_icd_dispatch &>(dispatch) = *clIcdDispatch;
+        dispatch.clIcdGetPlatformIDsKHR          = reinterpret_cast<clIcdGetPlatformIDsKHR_fn>(
+            clIcdDispatch->clGetExtensionFunctionAddress("clIcdGetPlatformIDsKHR"));
+    }
+    else if (error != nullptr)
+    {
+        ERR() << error;
+    }
     return dispatch;
 }