[UR] Fix platform search logic (#18033)

Change #17876 introduced a regression due to how platforms were
generated
examples and tests. This fixes those issues.

A fix for the no_platforms test is also included; which was failing due
to `UR_ADAPTERS_FORCE_LOAD=""` being treated as absent.

Closes #18032

Author: RossBrunton

unified-runtime/examples/codegen/codegen.cpp

@@ -69,15 +69,14 @@ get_platforms(std::vector<ur_adapter_handle_t> &adapters) {
     uint32_t adapterPlatformCount = 0;
     urPlatformGet(adapter, 0, nullptr, &adapterPlatformCount);
 
-    platforms.reserve(platformCount + adapterPlatformCount);
+    platforms.resize(platformCount + adapterPlatformCount);
     urPlatformGet(adapter, adapterPlatformCount, &platforms[platformCount],
                   &adapterPlatformCount);
     platformCount += adapterPlatformCount;
   }
   if (!platformCount) {
     throw std::runtime_error("No platforms available.");
   }
-  platforms.resize(platformCount);
 
   return platforms;
 }

unified-runtime/examples/hello_world/hello_world.cpp

@@ -56,7 +56,7 @@ int main(int, char *[]) {
       goto out;
     }
 
-    platforms.reserve(platformCount + adapterPlatformCount);
+    platforms.resize(platformCount + adapterPlatformCount);
     status = urPlatformGet(adapter, adapterPlatformCount,
                            &platforms[platformCount], &adapterPlatformCount);
     if (status != UR_RESULT_SUCCESS) {
@@ -66,7 +66,6 @@ int main(int, char *[]) {
     }
     platformCount += adapterPlatformCount;
   }
-  platforms.resize(platformCount);
 
   for (auto p : platforms) {
     ur_api_version_t api_version = {};

unified-runtime/test/loader/platforms/no_platforms.test

@@ -1,4 +1,4 @@
-RUN: UR_ADAPTERS_FORCE_LOAD="" UR_LOG_TEST="level:info;output:stdout;flush:debug" platforms-test
+RUN: UR_ADAPTERS_FORCE_LOAD="invalid.so" UR_LOG_TEST="level:info;output:stdout;flush:debug" platforms-test
 
 REQUIRES: linux
 

unified-runtime/test/loader/platforms/platforms.cpp

@@ -56,9 +56,9 @@ int main(int, char *[]) {
       out.error("urPlatformGet failed with return code: {}", status);
       goto out;
     }
-    out.info("urPlatformGet found {} platforms", platformCount);
+    out.info("urPlatformGet found {} platforms", adapterPlatformCount);
 
-    platforms.reserve(platformCount + adapterPlatformCount);
+    platforms.resize(platformCount + adapterPlatformCount);
     status = urPlatformGet(adapter, adapterPlatformCount,
                            &platforms[platformCount], &adapterPlatformCount);
     if (status != UR_RESULT_SUCCESS) {
@@ -67,7 +67,6 @@ int main(int, char *[]) {
     }
     platformCount += adapterPlatformCount;
   }
-  platforms.resize(platformCount);
 
   for (auto p : platforms) {
     size_t name_len;

unified-runtime/test/unit/print.h

@@ -69,7 +69,7 @@ struct UrPlatformGet {
 struct UrPlatformGetEmptyArray : UrPlatformGet {
   UrPlatformGetEmptyArray() : UrPlatformGet() {}
   const char *get_expected() {
-    return ".phAdapters = nullptr, .NumAdapters = 0, .NumEntries = 0, "
+    return ".hAdapter = nullptr, .NumEntries = 0, "
            ".phPlatforms = nullptr, .pNumPlatforms = "
            "nullptr";
   };
@@ -86,7 +86,7 @@ struct UrPlatformGetTwoPlatforms : UrPlatformGet {
     pNumPlatforms = &num_platforms;
   }
   const char *get_expected() {
-    return ".phAdapters = nullptr, .NumAdapters = 0, .NumEntries = 2, "
+    return ".hAdapter = nullptr, .NumEntries = 2, "
            ".phPlatforms = .+ \\{.+, .+\\}, "
            ".pNumPlatforms = .+ \\(2\\)";
   };