[SYCL][ASAN] apply only-needed when link asan libdevice (#12849)

This patch removes some unused code in sanitizer libdevice and also
appied 'only-needed' option when linking libsycl-santizer libdevice.

---------

Signed-off-by: jinge90 <ge.jin@intel.com>

Author: jinge90

clang/lib/Driver/ToolChains/SYCL.cpp

@@ -371,6 +371,8 @@ static llvm::SmallVector<StringRef, 16> SYCLDeviceLibList {
   "bfloat16", "crt", "cmath", "cmath-fp64", "complex", "complex-fp64",
 #if defined(_WIN32)
       "msvc-math",
+#else
+      "sanitizer",
 #endif
       "imf", "imf-fp64", "itt-compiler-wrappers", "itt-stubs",
       "itt-user-wrappers", "fallback-cassert", "fallback-cstring",

clang/test/Driver/sycl-device-lib.cpp

@@ -36,6 +36,7 @@
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown" "-input={{.*}}libsycl-fallback-imf.o" "-output={{.*}}libsycl-fallback-imf-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown" "-input={{.*}}libsycl-fallback-imf-fp64.o" "-output={{.*}}libsycl-fallback-imf-fp64-{{.*}}.o" "-unbundle"
 // SYCL_DEVICE_LIB_UNBUNDLE_DEFAULT-NEXT: clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown" "-input={{.*}}libsycl-fallback-imf-bf16.o" "-output={{.*}}libsycl-fallback-imf-bf16-{{.*}}.o" "-unbundle"
+
 /// ###########################################################################
 /// test sycl fallback device libraries are not linked by default
 // RUN: %clangxx -fsycl -fsycl-device-lib-jit-link %s --sysroot=%S/Inputs/SYCL -### 2>&1 \
@@ -251,3 +252,4 @@
 // SYCL_DEVICE_ASAN_MACRO-SAME: "USE_SYCL_DEVICE_ASAN"
 // SYCL_DEVICE_ASAN_MACRO-NEXT: llvm-link{{.*}}
 // SYCL_DEVICE_ASAN_MACRO:  clang-offload-bundler{{.*}} "-type=o" "-targets=sycl-spir64-unknown-unknown" "-input={{.*}}libsycl-sanitizer.o" "-output={{.*}}libsycl-sanitizer-{{.*}}.o" "-unbundle"
+// SYCL_DEVICE_ASAN_MACRO: llvm-link{{.*}} "-only-needed" "{{.*}}" "-o" "{{.*}}.bc" "--suppress-warnings"

libdevice/include/spir_global_var.hpp

@@ -11,15 +11,6 @@
 // Treat this header as system one to workaround frontend's restriction
 #pragma clang system_header
 
-#ifndef SPIR_GLOBAL_VAR
-#ifdef __SYCL_DEVICE_ONLY__
-#define SPIR_GLOBAL_VAR __attribute__((sycl_global_var))
-#else
-#warning "SPIR_GLOBAL_VAR not defined in host mode. Defining as empty macro."
-#define SPIR_GLOBAL_VAR
-#endif
-#endif
-
 #define __SYCL_GLOBAL__ __attribute__((opencl_global))
 #define __SYCL_LOCAL__ __attribute__((opencl_local))
 #define __SYCL_PRIVATE__ __attribute__((opencl_private))