SystemInfo: Find primary with EnumDisplayDevices

src/gpu_info_util/SystemInfo.h

@@ -43,8 +43,12 @@ struct SystemInfo
     bool isOptimus       = false;
     bool isAMDSwitchable = false;
 
+    // Only available on macOS
     std::string machineModelName;
     std::string machineModelVersion;
+
+    // Only available on Windows, set even on failure.
+    std::string primaryDisplayDeviceId;
 };
 
 bool GetSystemInfo(SystemInfo *info);

src/gpu_info_util/SystemInfo_win.cpp

@@ -8,10 +8,16 @@
 
 #include "gpu_info_util/SystemInfo_internal.h"
 
+#include "common/debug.h"
+#include "common/string_utils.h"
+
 // Windows.h needs to be included first
 #include <windows.h>
 
 #if defined(GPU_INFO_USE_SETUPAPI)
+// Remove parts of commctrl.h that have compile errors
+#define NOTOOLBAR
+#define NOTOOLTIPS
 #include <cfgmgr32.h>
 #include <setupapi.h>
 #elif defined(GPU_INFO_USE_DXGI)
@@ -30,6 +36,23 @@ namespace angle
 namespace
 {
 
+// Returns the CM device ID of the primary GPU.
+std::string GetPrimaryDisplayDeviceId()
+{
+    DISPLAY_DEVICEA displayDevice;
+    displayDevice.cb = sizeof(DISPLAY_DEVICEA);
+
+    for (int i = 0; EnumDisplayDevicesA(nullptr, i, &displayDevice, 0); ++i)
+    {
+        if (displayDevice.StateFlags & DISPLAY_DEVICE_PRIMARY_DEVICE)
+        {
+            return displayDevice.DeviceID;
+        }
+    }
+
+    return "";
+}
+
 #if defined(GPU_INFO_USE_SETUPAPI)
 
 std::string GetRegistryStringValue(HKEY key, const char *valueName)
@@ -173,6 +196,9 @@ bool GetDevicesFromDXGI(std::vector<GPUDeviceInfo> *devices)
 
 bool GetSystemInfo(SystemInfo *info)
 {
+    // Get the CM device ID first so that it is returned even in error cases.
+    info->primaryDisplayDeviceId = GetPrimaryDisplayDeviceId();
+
 #if defined(GPU_INFO_USE_SETUPAPI)
     if (!GetDevicesFromRegistry(&info->gpus))
     {
@@ -194,6 +220,27 @@ bool GetSystemInfo(SystemInfo *info)
 
     FindPrimaryGPU(info);
 
+    // Override the primary GPU index with what we gathered from EnumDisplayDevices
+    uint32_t primaryVendorId = 0;
+    uint32_t primaryDeviceId = 0;
+
+    if (!CMDeviceIDToDeviceAndVendorID(info->primaryDisplayDeviceId, &primaryVendorId,
+                                       &primaryDeviceId))
+    {
+        return false;
+    }
+
+    bool foundPrimary = false;
+    for (size_t i = 0; i < info->gpus.size(); ++i)
+    {
+        if (info->gpus[i].vendorId == primaryVendorId && info->gpus[i].deviceId == primaryDeviceId)
+        {
+            info->primaryGPUIndex = static_cast<int>(i);
+            foundPrimary          = true;
+        }
+    }
+    ASSERT(foundPrimary);
+
     // nvd3d9wrap.dll is loaded into all processes when Optimus is enabled.
     HMODULE nvd3d9wrap = GetModuleHandleW(L"nvd3d9wrap.dll");
     info->isOptimus    = nvd3d9wrap != nullptr;

src/tests/util_tests/PrintSystemInfoTest.cpp

@@ -88,6 +88,11 @@ TEST(PrintSystemInfoTest, Print)
         std::cout << "Machine Model: " << info.machineModelName << " version "
                   << info.machineModelVersion << "\n";
     }
+
+    if (!info.primaryDisplayDeviceId.empty())
+    {
+        std::cout << "Primary Display Device: " << info.primaryDisplayDeviceId << "\n";
+    }
     std::cout << std::endl;
 #else
     std::cerr << "GetSystemInfo not implemented, skipping" << std::endl;