[SYCL] Fix issues caught by static analyzer (#12253)

* Don't throw exceptions in destructors (they are explicitely marked as
noexcept)
* Make sure that MPlatform data member of context_impl is always
initialized.
* Assign default value to MCacheMutex* in kernel_impl.

Author: againull

sycl/source/detail/buffer_impl.cpp

@@ -74,12 +74,11 @@ buffer_impl::getNativeVector(backend BackendName) const {
     auto Platform = Ctx->getPlatformImpl();
     // If Host Shared Memory is not supported then there is alloca for host that
     // doesn't have platform
-    if (!Platform)
+    if (!Platform || (Platform->getBackend() != BackendName))
       continue;
+
     auto Plugin = Platform->getPlugin();
 
-    if (Platform->getBackend() != BackendName)
-      continue;
     if (Platform->getBackend() == backend::opencl) {
       Plugin->call<PiApiKind::piMemRetain>(NativeMem);
     }

sycl/source/detail/context_impl.cpp

@@ -32,7 +32,9 @@ namespace detail {
 context_impl::context_impl(const device &Device, async_handler AsyncHandler,
                            const property_list &PropList)
     : MOwnedByRuntime(true), MAsyncHandler(AsyncHandler), MDevices(1, Device),
-      MContext(nullptr), MPlatform(), MPropList(PropList),
+      MContext(nullptr),
+      MPlatform(detail::getSyclObjImpl(Device.get_platform())),
+      MPropList(PropList),
       MHostContext(detail::getSyclObjImpl(Device)->is_host()),
       MSupportBufferLocationByDevices(NotChecked) {
   MKernelProgramCache.setContextPtr(this);
@@ -100,6 +102,10 @@ context_impl::context_impl(sycl::detail::pi::PiContext PiContext,
             Platform->getOrMakeDeviceImpl(Dev, Platform)));
       }
       MPlatform = Platform;
+    } else {
+      throw invalid_parameter_error(
+          "No devices in the provided device list and native context.",
+          PI_ERROR_INVALID_VALUE);
     }
   }
   // TODO catch an exception and put it to list of asynchronous exceptions

sycl/source/detail/context_impl.hpp

@@ -191,7 +191,10 @@ class context_impl {
   }
 
   // Returns the backend of this context
-  backend getBackend() const { return MPlatform->getBackend(); }
+  backend getBackend() const {
+    assert(MPlatform && "MPlatorm must be not null");
+    return MPlatform->getBackend();
+  }
 
   /// Given a PiDevice, returns the matching shared_ptr<device_impl>
   /// within this context. May return nullptr if no match discovered.

sycl/source/detail/kernel_impl.hpp

@@ -195,7 +195,7 @@ class kernel_impl {
   bool MIsInterop = false;
   std::mutex MNoncacheableEnqueueMutex;
   const KernelArgMask *MKernelArgMaskPtr;
-  std::mutex *MCacheMutex;
+  std::mutex *MCacheMutex = nullptr;
 
   bool isBuiltInKernel(const device &Device) const;
   void checkIfValidForNumArgsInfoQuery() const;

sycl/source/detail/kernel_program_cache.hpp

@@ -94,8 +94,11 @@ class KernelProgramCache {
       Val = nullptr;
     }
     ~ProgramBuildResult() {
-      if (Val)
-        Plugin->call<PiApiKind::piProgramRelease>(Val);
+      if (Val) {
+        sycl::detail::pi::PiResult Err =
+            Plugin->call_nocheck<PiApiKind::piProgramRelease>(Val);
+        __SYCL_CHECK_OCL_CODE_NO_EXC(Err);
+      }
     }
   };
   using ProgramBuildResultPtr = std::shared_ptr<ProgramBuildResult>;
@@ -126,8 +129,11 @@ class KernelProgramCache {
       Val.first = nullptr;
     }
     ~KernelBuildResult() {
-      if (Val.first)
-        Plugin->call<PiApiKind::piKernelRelease>(Val.first);
+      if (Val.first) {
+        sycl::detail::pi::PiResult Err =
+            Plugin->call_nocheck<PiApiKind::piKernelRelease>(Val.first);
+        __SYCL_CHECK_OCL_CODE_NO_EXC(Err);
+      }
     }
   };
   using KernelBuildResultPtr = std::shared_ptr<KernelBuildResult>;