[HIP] Add option -fgpu-allow-device-init

Add this option to allow device side class type global variables
with non-trivial ctor/dtor. device side init/fini functions will
be emitted, which will be executed by HIP runtime when
the fat binary is loaded/unloaded.

This feature is to facilitate implementation of device side
sanitizer which requires global vars with non-trival ctors.

By default this option is disabled.

Differential Revision: https://reviews.llvm.org/D69268

clang/include/clang/Basic/DiagnosticCommonKinds.td

@@ -304,6 +304,11 @@ def err_arcmt_nsinvocation_ownership : Error<"NSInvocation's %0 is not safe to b
 def err_openclcxx_not_supported : Error<
   "'%0' is not supported in C++ for OpenCL">;
 
+// HIP
+def warn_ignore_hip_only_option : Warning<
+  "'%0' is ignored since it is only supported for HIP">,
+  InGroup<HIPOnly>;
+
 // OpenMP
 def err_omp_more_one_clause : Error<
   "directive '#pragma omp %0' cannot contain more than one '%1' clause%select{| with '%3' name modifier| with 'source' dependence}2">;

clang/include/clang/Basic/DiagnosticGroups.td

@@ -1077,6 +1077,10 @@ def SerializedDiagnostics : DiagGroup<"serialized-diagnostics">;
 // compiling CUDA C/C++ but which is not compatible with the CUDA spec.
 def CudaCompat : DiagGroup<"cuda-compat">;
 
+// A warning group for warnings about features supported by HIP but
+// ignored by CUDA.
+def HIPOnly : DiagGroup<"hip-only">;
+
 // Warnings which cause linking of the runtime libraries like
 // libc and the CRT to be skipped.
 def AVRRtlibLinkingQuirks : DiagGroup<"avr-rtlib-linking-quirks">;

clang/include/clang/Basic/LangOptions.def

@@ -224,6 +224,7 @@ LANGOPT(CUDAAllowVariadicFunctions, 1, 0, "allowing variadic functions in CUDA d
 LANGOPT(CUDAHostDeviceConstexpr, 1, 1, "treating unattributed constexpr functions as __host__ __device__")
 LANGOPT(CUDADeviceApproxTranscendentals, 1, 0, "using approximate transcendental functions")
 LANGOPT(GPURelocatableDeviceCode, 1, 0, "generate relocatable device code")
+LANGOPT(GPUAllowDeviceInit, 1, 0, "allowing device side global init functions for HIP")
 
 LANGOPT(SYCLIsDevice      , 1, 0, "Generate code for SYCL device")
 

clang/include/clang/Driver/Options.td

@@ -602,6 +602,9 @@ def fhip_dump_offload_linker_script : Flag<["-"], "fhip-dump-offload-linker-scri
 def fhip_new_launch_api : Flag<["-"], "fhip-new-launch-api">,
   Flags<[CC1Option]>, HelpText<"Use new kernel launching API for HIP.">;
 def fno_hip_new_launch_api : Flag<["-"], "fno-hip-new-launch-api">;
+def fgpu_allow_device_init : Flag<["-"], "fgpu-allow-device-init">,
+  Flags<[CC1Option]>, HelpText<"Allow device side init function in HIP">;
+def fno_gpu_allow_device_init : Flag<["-"], "fno-gpu-allow-device-init">;
 def libomptarget_nvptx_path_EQ : Joined<["--"], "libomptarget-nvptx-path=">, Group<i_Group>,
   HelpText<"Path to libomptarget-nvptx libraries">;
 def dD : Flag<["-"], "dD">, Group<d_Group>, Flags<[CC1Option]>,

clang/lib/CodeGen/CGDeclCXX.cpp

@@ -437,7 +437,7 @@ CodeGenModule::EmitCXXGlobalVarDeclInitFunc(const VarDecl *D,
   // that are of class type, cannot have a non-empty constructor. All
   // the checks have been done in Sema by now. Whatever initializers
   // are allowed are empty and we just need to ignore them here.
-  if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
+  if (getLangOpts().CUDAIsDevice && !getLangOpts().GPUAllowDeviceInit &&
       (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
        D->hasAttr<CUDASharedAttr>()))
     return;
@@ -608,6 +608,11 @@ CodeGenModule::EmitCXXGlobalInitFunc() {
     Fn->setCallingConv(llvm::CallingConv::SPIR_KERNEL);
   }
 
+  if (getLangOpts().HIP) {
+    Fn->setCallingConv(llvm::CallingConv::AMDGPU_KERNEL);
+    Fn->addFnAttr("device-init");
+  }
+
   CXXGlobalInits.clear();
 }
 

clang/lib/Driver/ToolChains/HIP.cpp

@@ -292,6 +292,10 @@ void HIPToolChain::addClangTargetOptions(
                          false))
     CC1Args.push_back("-fgpu-rdc");
 
+  if (DriverArgs.hasFlag(options::OPT_fgpu_allow_device_init,
+                         options::OPT_fno_gpu_allow_device_init, false))
+    CC1Args.push_back("-fgpu-allow-device-init");
+
   // Default to "hidden" visibility, as object level linking will not be
   // supported for the foreseeable future.
   if (!DriverArgs.hasArg(options::OPT_fvisibility_EQ,

clang/lib/Frontend/CompilerInvocation.cpp

@@ -2528,6 +2528,13 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
     Opts.CUDADeviceApproxTranscendentals = 1;
 
   Opts.GPURelocatableDeviceCode = Args.hasArg(OPT_fgpu_rdc);
+  if (Args.hasArg(OPT_fgpu_allow_device_init)) {
+    if (Opts.HIP)
+      Opts.GPUAllowDeviceInit = 1;
+    else
+      Diags.Report(diag::warn_ignore_hip_only_option)
+          << Args.getLastArg(OPT_fgpu_allow_device_init)->getAsString(Args);
+  }
   Opts.HIPUseNewLaunchAPI = Args.hasArg(OPT_fhip_new_launch_api);
 
   if (Opts.ObjC) {

clang/lib/Sema/SemaCUDA.cpp

@@ -492,6 +492,8 @@ void Sema::checkAllowedCUDAInitializer(VarDecl *VD) {
   const Expr *Init = VD->getInit();
   if (VD->hasAttr<CUDADeviceAttr>() || VD->hasAttr<CUDAConstantAttr>() ||
       VD->hasAttr<CUDASharedAttr>()) {
+    if (LangOpts.GPUAllowDeviceInit)
+      return;
     assert(!VD->isStaticLocal() || VD->hasAttr<CUDASharedAttr>());
     bool AllowedInit = false;
     if (const CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(Init))

clang/test/CodeGenCUDA/device-init-fun.cu

@@ -0,0 +1,19 @@
+// REQUIRES: amdgpu-registered-target
+
+// RUN: %clang_cc1 -triple amdgcn -fcuda-is-device -std=c++11 \
+// RUN:     -fgpu-allow-device-init -x hip \
+// RUN:     -fno-threadsafe-statics -emit-llvm -o - %s \
+// RUN:     | FileCheck %s
+
+#include "Inputs/cuda.h"
+
+// CHECK: define internal amdgpu_kernel void @_GLOBAL__sub_I_device_init_fun.cu() #[[ATTR:[0-9]*]]
+// CHECK: attributes #[[ATTR]] = {{.*}}"device-init"
+
+__device__ void f();
+
+struct A {
+  __device__ A() { f(); }
+};
+
+__device__ A a;

clang/test/Frontend/warn-device-init-fun.cu

@@ -0,0 +1,8 @@
+// REQUIRES: nvptx-registered-target
+
+// RUN: %clang_cc1 -triple nvptx -fcuda-is-device \
+// RUN:     -fgpu-allow-device-init \
+// RUN:      %s 2>&1 | FileCheck %s
+
+// CHECK: warning: '-fgpu-allow-device-init' is ignored since it is only supported for HIP
+