fix illegal usage of parameter of kernel function in main function

Author: ZuseZ4

compiler/rustc_codegen_llvm/src/builder/gpu_offload.rs

@@ -366,7 +366,8 @@ fn gen_call_handling<'ll>(
         let arg_name = format!("{name}.addr");
         let alloca = builder.direct_alloca(in_ty, Align::EIGHT, &arg_name);
 
-        builder.store(p, alloca, Align::EIGHT);
+        let v = unsafe { llvm::LLVMGetOperand(kernel_call, index as u32).unwrap() };
+        builder.store(v, alloca, Align::EIGHT);
         let val = builder.load(in_ty, alloca, Align::EIGHT);
         let gep = builder.inbounds_gep(cx.type_f32(), val, &[i32_0]);
         vals.push(val);
@@ -510,7 +511,9 @@ fn gen_call_handling<'ll>(
         let next = llvm::LLVMGetNextInstruction(offload_success).unwrap();
         dbg!(&next);
         llvm::LLVMRustPositionAfter(builder.llbuilder, next);
+        let called_kernel = llvm::LLVMGetCalledValue(next).unwrap();
         llvm::LLVMInstructionEraseFromParent(next);
+        dbg!(&called_kernel);
     }
 
     // Step 4)
@@ -521,6 +524,10 @@ fn gen_call_handling<'ll>(
 
     builder.call(mapper_fn_ty, unregister_lib_decl, &[tgt_bin_desc_alloca], None);
 
+    drop(builder);
+    unsafe { llvm::LLVMDeleteFunction(called) };
+    dbg!("survived");
+
     // With this we generated the following begin and end mappers. We could easily generate the
     // update mapper in an update.
     // call void @__tgt_target_data_begin_mapper(ptr @1, i64 -1, i32 3, ptr %27, ptr %28, ptr %29, ptr @.offload_maptypes, ptr null, ptr null)