[SYCL][ClangLinkerWrapper] Add -use-sycl-post-link-tool command line option to clang-linker-wrapper (#15374)

Previously clang-linker-wrapper used -sycl-module-split-mode option to
decide whether to use sycl-post-link tool or not to use. This patch adds
options for a explicit specifiyng usage of tool and library.

Author: maksimsab

clang/test/Driver/linker-wrapper-sycl.cpp

@@ -25,7 +25,7 @@
 
 // Check sycl-module-split-mode command line option.
 // This option uses split library instead of sycl-post-link tool.
-// RUN: clang-linker-wrapper -sycl-module-split-mode=auto -sycl-device-libraries=%t.devicelib.o -sycl-post-link-options="SYCL_POST_LINK_OPTIONS" -llvm-spirv-options="LLVM_SPIRV_OPTIONS" "--host-triple=x86_64-unknown-linux-gnu" "--triple=spir64" "--linker-path=/usr/bin/ld" "--" HOST_LINKER_FLAGS "-dynamic-linker" HOST_DYN_LIB "-o" "a.out" HOST_LIB_PATH HOST_STAT_LIB %t.o --dry-run 2>&1 | FileCheck -check-prefix=CHK-SPLIT-CMDS %s
+// RUN: clang-linker-wrapper -no-use-sycl-post-link-tool -sycl-module-split-mode=auto -sycl-device-libraries=%t.devicelib.o -sycl-post-link-options="SYCL_POST_LINK_OPTIONS" -llvm-spirv-options="LLVM_SPIRV_OPTIONS" "--host-triple=x86_64-unknown-linux-gnu" "--triple=spir64" "--linker-path=/usr/bin/ld" "--" HOST_LINKER_FLAGS "-dynamic-linker" HOST_DYN_LIB "-o" "a.out" HOST_LIB_PATH HOST_STAT_LIB %t.o --dry-run 2>&1 | FileCheck -check-prefix=CHK-SPLIT-CMDS %s
 // CHK-SPLIT-CMDS: "{{.*}}spirv-to-ir-wrapper" {{.*}} -o [[FIRSTLLVMLINKIN:.*]].bc --llvm-spirv-opts --spirv-preserve-auxdata --spirv-target-env=SPV-IR --spirv-builtin-format=global
 // CHK-SPLIT-CMDS-NEXT: "{{.*}}llvm-link" [[FIRSTLLVMLINKIN]].bc -o [[FIRSTLLVMLINKOUT:.*]].bc --suppress-warnings
 // CHK-SPLIT-CMDS-NEXT: "{{.*}}llvm-link" -only-needed [[FIRSTLLVMLINKOUT]].bc {{.*}}.bc -o [[SECONDLLVMLINKOUT:.*]].bc --suppress-warnings
@@ -36,6 +36,13 @@
 // CHK-SPLIT-CMDS-NEXT: "{{.*}}clang"{{.*}} -c -o [[LLCOUT:.*]] [[WRAPPEROUT]].bc
 // CHK-SPLIT-CMDS-NEXT: "{{.*}}/ld" -- HOST_LINKER_FLAGS -dynamic-linker HOST_DYN_LIB -o a.out [[LLCOUT]] HOST_LIB_PATH HOST_STAT_LIB {{.*}}.o
 
+// Check errors with -[no-]use-sycl-post-link-tool.
+// RUN: not clang-linker-wrapper -sycl-module-split-mode=auto -sycl-device-libraries=%t.devicelib.o -sycl-post-link-options="SYCL_POST_LINK_OPTIONS" -llvm-spirv-options="LLVM_SPIRV_OPTIONS" "--host-triple=x86_64-unknown-linux-gnu" "--triple=spir64" "--linker-path=/usr/bin/ld" "--" HOST_LINKER_FLAGS "-dynamic-linker" HOST_DYN_LIB "-o" "a.out" HOST_LIB_PATH HOST_STAT_LIB %t.o --dry-run 2>&1 | FileCheck -check-prefix=CHK-SYCL-POST-LINK-TOOL-ERROR %s
+// CHK-SYCL-POST-LINK-TOOL-ERROR: error: -sycl-module-split-mode should be used with the -no-use-sycl-post-link-tool command line option.
+
+// RUN: not clang-linker-wrapper -use-sycl-post-link-tool -no-use-sycl-post-link-tool -sycl-module-split-mode=auto -sycl-device-libraries=%t.devicelib.o -sycl-post-link-options="SYCL_POST_LINK_OPTIONS" -llvm-spirv-options="LLVM_SPIRV_OPTIONS" "--host-triple=x86_64-unknown-linux-gnu" "--triple=spir64" "--linker-path=/usr/bin/ld" "--" HOST_LINKER_FLAGS "-dynamic-linker" HOST_DYN_LIB "-o" "a.out" HOST_LIB_PATH HOST_STAT_LIB %t.o --dry-run 2>&1 | FileCheck -check-prefix=CHK-SYCL-POST-LINK-TOOL-ERROR2 %s
+// CHK-SYCL-POST-LINK-TOOL-ERROR2: error: -use-sycl-post-link-tool and -no-use-sycl-post-link-tool options can't be used together.
+
 /// check for PIC for device wrap compilation when using -shared
 // RUN: clang-linker-wrapper -sycl-device-libraries=%t.devicelib.o -sycl-post-link-options="SYCL_POST_LINK_OPTIONS" -llvm-spirv-options="LLVM_SPIRV_OPTIONS" "--host-triple=x86_64-unknown-linux-gnu" "--triple=spir64" "--linker-path=/usr/bin/ld" -shared "--" HOST_LINKER_FLAGS "-dynamic-linker" HOST_DYN_LIB "-o" "a.out" HOST_LIB_PATH HOST_STAT_LIB %t.o --dry-run 2>&1 | FileCheck -check-prefix=CHK-SHARED %s
 // CHK-SHARED: "{{.*}}clang"{{.*}} -fPIC

clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp

@@ -154,6 +154,8 @@ static std::atomic<bool> LTOError;
 
 static std::optional<llvm::module_split::IRSplitMode> SYCLModuleSplitMode;
 
+static bool UseSYCLPostLinkTool;
+
 SmallString<128> SPIRVDumpDir;
 
 using OffloadingImage = OffloadBinary::OffloadingImage;
@@ -2392,10 +2394,10 @@ Expected<SmallVector<StringRef>> linkAndWrapDeviceFiles(
       SmallVector<StringRef> InputFilesSYCL;
       InputFilesSYCL.emplace_back(*TmpOutputOrErr);
       auto SplitModulesOrErr =
-          SYCLModuleSplitMode
-              ? sycl::runSYCLSplitLibrary(InputFilesSYCL, LinkerArgs,
-                                          *SYCLModuleSplitMode)
-              : sycl::runSYCLPostLinkTool(InputFilesSYCL, LinkerArgs);
+          UseSYCLPostLinkTool
+              ? sycl::runSYCLPostLinkTool(InputFilesSYCL, LinkerArgs)
+              : sycl::runSYCLSplitLibrary(InputFilesSYCL, LinkerArgs,
+                                          *SYCLModuleSplitMode);
       if (!SplitModulesOrErr)
         return SplitModulesOrErr.takeError();
 
@@ -2961,7 +2963,19 @@ int main(int Argc, char **Argv) {
     timeTraceProfilerInitialize(Granularity, Argv[0]);
   }
 
+  UseSYCLPostLinkTool = Args.hasFlag(OPT_use_sycl_post_link_tool,
+                                     OPT_no_use_sycl_post_link_tool, true);
+  if (!UseSYCLPostLinkTool && Args.hasArg(OPT_use_sycl_post_link_tool))
+    reportError(createStringError("-use-sycl-post-link-tool and "
+                                  "-no-use-sycl-post-link-tool options can't "
+                                  "be used together."));
+
   if (Args.hasArg(OPT_sycl_module_split_mode_EQ)) {
+    if (UseSYCLPostLinkTool)
+      reportError(createStringError(
+          "-sycl-module-split-mode should be used with "
+          "the -no-use-sycl-post-link-tool command line option."));
+
     StringRef StrMode = Args.getLastArgValue(OPT_sycl_module_split_mode_EQ);
     SYCLModuleSplitMode = module_split::convertStringToSplitMode(StrMode);
     if (!SYCLModuleSplitMode)

clang/tools/clang-linker-wrapper/LinkerWrapperOpts.td

@@ -184,6 +184,15 @@ def sycl_module_split_mode_EQ :
   Flags<[WrapperOnlyOption]>,
   HelpText<"Option that turns on split library with the given split mode">;
 
+// TODO: Options will be removed when the sycl-post-link tool becomes removed.
+def use_sycl_post_link_tool : Flag<["--", "-"], "use-sycl-post-link-tool">,
+  Flags<[WrapperOnlyOption]>,
+  HelpText<"Use the sycl-post-link tool. On by default">;
+
+def no_use_sycl_post_link_tool : Flag<["--", "-"], "no-use-sycl-post-link-tool">,
+  Flags<[WrapperOnlyOption]>,
+  HelpText<"Use a SYCL library instead of sycl-post-link tool. (experimental)">;
+
 // Special option to pass in llvm-spirv options
 def llvm_spirv_options_EQ : Joined<["--", "-"], "llvm-spirv-options=">,
   Flags<[WrapperOnlyOption]>,