Define function to return string literal for checking all extensions

---------------------------------------------------------------------------

The string literall returned is statically allocated so that it is safe to return one from a function.

The reason why std::string was not used. once modified, the c_cstr() pointer may no longer be valid. Futher tsan reported a heap use after free error if the acl_platform_extensions return std::string instead.

Author: sherry-yuan

include/acl_platform.h

@@ -21,6 +21,7 @@ extern int platform_owner_tid;
 void acl_init_platform(void);
 void acl_finalize_init_platform(unsigned int num_devices,
                                 const cl_device_id *devices);
+const char *acl_platform_extensions(void);
 
 #if defined(__cplusplus)
 } /* extern "C" */

src/acl_platform.cpp

@@ -257,6 +257,34 @@ int acl_platform_is_valid(cl_platform_id platform) {
   return platform == &acl_platform;
 }
 
+const char *acl_platform_extensions() {
+  return "cl_khr_byte_addressable_store" // yes, we have correct access to
+                                         // individual bytes!
+         " cles_khr_int64" // yes, we support 64-bit ints in the embedded
+                           // profile
+
+         " cl_khr_icd"
+#if ACL_SUPPORT_IMAGES == 1
+         " cl_khr_3d_image_writes"
+#endif
+#if ACL_SUPPORT_DOUBLE == 1
+         " cl_khr_fp64"
+#endif
+#ifdef ACL_120
+         " cl_khr_global_int32_base_atomics"
+         " cl_khr_global_int32_extended_atomics"
+         " cl_khr_local_int32_base_atomics"
+         " cl_khr_local_int32_extended_atomics"
+#endif
+#ifndef __arm__
+  // Add the following once all USM APIs are implemented, Intel publishes
+  // the spec, and published USM conformance tests pass
+  //" cl_intel_unified_shared_memory"
+#endif
+         " cl_intel_create_buffer_with_properties"
+         " cl_intel_mem_channel_property";
+}
+
 // Initialize the internal bookkeeping based on the system definition
 // provided to us.
 void acl_init_platform(void) {
@@ -298,31 +326,7 @@ void acl_init_platform(void) {
   // The extensions string specifies the extensions supported by our framework.
   // To add an extension, append a flag name and separate it from others using a
   // space.
-  acl_platform.extensions =
-      "cl_khr_byte_addressable_store" // yes, we have correct access to
-                                      // individual bytes!
-      " cles_khr_int64" // yes, we support 64-bit ints in the embedded profile
-
-      " cl_khr_icd"
-#if ACL_SUPPORT_IMAGES == 1
-      " cl_khr_3d_image_writes"
-#endif
-#if ACL_SUPPORT_DOUBLE == 1
-      " cl_khr_fp64"
-#endif
-#ifdef ACL_120
-      " cl_khr_global_int32_base_atomics"
-      " cl_khr_global_int32_extended_atomics"
-      " cl_khr_local_int32_base_atomics"
-      " cl_khr_local_int32_extended_atomics"
-#endif
-#ifndef __arm__
-  // Add the following once all USM APIs are implemented, Intel publishes
-  // the spec, and published USM conformance tests pass
-  //" cl_intel_unified_shared_memory"
-#endif
-      " cl_intel_create_buffer_with_properties"
-      " cl_intel_mem_channel_property";
+  acl_platform.extensions = acl_platform_extensions();
 
   acl_platform.profile = "EMBEDDED_PROFILE";
   acl_platform.hal = acl_get_hal();

test/acl_device_test.cpp

@@ -14,6 +14,7 @@
 
 #include <acl.h>
 #include <acl_context.h>
+#include <acl_platform.h>
 #include <acl_types.h>
 #include <acl_util.h>
 
@@ -326,6 +327,10 @@ MT_TEST(DeviceInfo, basic) {
 
     CHECK(size_ret > 0);
 
+    if (queries[i] == CL_DEVICE_EXTENSIONS) {
+      CHECK(strcmp(str, acl_platform_extensions()) == 0);
+    }
+
     switch (queries[i]) {
     case CL_DEVICE_VENDOR:
     case CL_DEVICE_VERSION: