[clang] Delay checking of -fopenmp-host-ir-file-path

clang/include/clang/Basic/DiagnosticDriverKinds.td

@@ -361,9 +361,6 @@ def err_drv_optimization_remark_format : Error<
 def err_drv_no_neon_modifier : Error<"[no]neon is not accepted as modifier, please use [no]simd instead">;
 def err_drv_invalid_omp_target : Error<"OpenMP target is invalid: '%0'">;
 def err_drv_incompatible_omp_arch : Error<"OpenMP target architecture '%0' pointer size is incompatible with host '%1'">;
-def err_drv_omp_host_ir_file_not_found : Error<
-  "provided host compiler IR file '%0' is required to generate code for OpenMP "
-  "target regions but cannot be found">;
 def err_drv_omp_host_target_not_supported : Error<
   "target '%0' is not a supported OpenMP host target">;
 def err_drv_expecting_fopenmp_with_fopenmp_targets : Error<

clang/include/clang/Basic/DiagnosticFrontendKinds.td

@@ -308,6 +308,9 @@ def err_target_unsupported_type_for_abi
     : Error<"%0 requires %1 type support, but ABI '%2' does not support it">;
 }
 
+def err_omp_host_ir_file_not_found : Error<
+  "provided host compiler IR file '%0' is required to generate code for OpenMP "
+  "target regions but cannot be found">;
 def err_alias_to_undefined : Error<
   "%select{alias|ifunc}0 must point to a defined "
   "%select{variable or |}1function">;

clang/include/clang/Driver/Options.td

@@ -8645,7 +8645,8 @@ def fopenmp_is_target_device : Flag<["-"], "fopenmp-is-target-device">,
   HelpText<"Generate code only for an OpenMP target device.">;
 def : Flag<["-"], "fopenmp-is-device">, Alias<fopenmp_is_target_device>;
 def fopenmp_host_ir_file_path : Separate<["-"], "fopenmp-host-ir-file-path">,
-  HelpText<"Path to the IR file produced by the frontend for the host.">;
+  HelpText<"Path to the IR file produced by the frontend for the host.">,
+  MarshallingInfoString<LangOpts<"OMPHostIRFile">>;
 
 } // let Visibility = [CC1Option, FC1Option]
 

clang/lib/CodeGen/CodeGenModule.cpp

@@ -582,6 +582,10 @@ void CodeGenModule::createOpenCLRuntime() {
 }
 
 void CodeGenModule::createOpenMPRuntime() {
+  if (!LangOpts.OMPHostIRFile.empty() && !FS->exists(LangOpts.OMPHostIRFile))
+    Diags.Report(diag::err_omp_host_ir_file_not_found)
+        << LangOpts.OMPHostIRFile;
+
   // Select a specialized code generation class based on the target, if any.
   // If it does not exist use the default implementation.
   switch (getTriple().getArch()) {

clang/lib/Frontend/CompilerInvocation.cpp

@@ -3907,9 +3907,6 @@ void CompilerInvocationBase::GenerateLangArgs(const LangOptions &Opts,
     GenerateArg(Consumer, OPT_offload_targets_EQ, Targets);
   }
 
-  if (!Opts.OMPHostIRFile.empty())
-    GenerateArg(Consumer, OPT_fopenmp_host_ir_file_path, Opts.OMPHostIRFile);
-
   if (Opts.OpenMPCUDAMode)
     GenerateArg(Consumer, OPT_fopenmp_cuda_mode);
 
@@ -4405,15 +4402,6 @@ bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
     }
   }
 
-  // Get OpenMP host file path if any and report if a non existent file is
-  // found
-  if (Arg *A = Args.getLastArg(options::OPT_fopenmp_host_ir_file_path)) {
-    Opts.OMPHostIRFile = A->getValue();
-    if (!llvm::sys::fs::exists(Opts.OMPHostIRFile))
-      Diags.Report(diag::err_drv_omp_host_ir_file_not_found)
-          << Opts.OMPHostIRFile;
-  }
-
   // Set CUDA mode for OpenMP target NVPTX/AMDGCN if specified in options
   Opts.OpenMPCUDAMode = Opts.OpenMPIsTargetDevice &&
                         (T.isNVPTX() || T.isAMDGCN()) &&