Add OpenCL metadata for kernel arg names. This output is controlled via a flag as noted in the OpenCL Spec.

Includes a test case.

llvm-svn: 160092

clang/include/clang/Driver/Options.td

@@ -39,6 +39,7 @@ def clang_i_Group         : OptionGroup<"<clang i group>">, Group<i_Group>;
 def m_Group               : OptionGroup<"<m group>">, Group<CompileOnly_Group>;
 def m_x86_Features_Group  : OptionGroup<"<m x86 features group>">, Group<m_Group>;
 def m_hexagon_Features_Group  : OptionGroup<"<m hexagon features group>">, Group<m_Group>;
+def opencl_Group          : OptionGroup<"<opencl group>">;
 def u_Group               : OptionGroup<"<u group>">;
 
 def pedantic_Group        : OptionGroup<"<pedantic group>">,
@@ -247,6 +248,8 @@ def bind__at__load : Flag<"-bind_at_load">;
 def bundle__loader : Separate<"-bundle_loader">;
 def bundle : Flag<"-bundle">;
 def b : JoinedOrSeparate<"-b">, Flags<[Unsupported]>;
+def cl_kernel_arg_info : Flag<"-cl-kernel-arg-info">, Flags<[CC1Option]>, Group<opencl_Group>,
+HelpText<"OpenCL only. This option allows the compiler to store information about the arguments of a kernel(s)"> ;
 def client__name : JoinedOrSeparate<"-client_name">;
 def combine : Flag<"-combine">, Flags<[DriverOption, Unsupported]>;
 def compatibility__version : JoinedOrSeparate<"-compatibility_version">;

clang/include/clang/Frontend/CodeGenOptions.h

@@ -71,6 +71,7 @@ public:
                                   ///< subroutine.
   unsigned EmitGcovArcs      : 1; ///< Emit coverage data files, aka. GCDA.
   unsigned EmitGcovNotes     : 1; ///< Emit coverage "notes" files, aka GCNO.
+  unsigned EmitOpenCLArgMetadata : 1; /// Emit OpenCL kernel arg metadata.
   unsigned ForbidGuardVariables : 1; ///< Issue errors if C++ guard variables
                                      ///< are required
   unsigned FunctionSections  : 1; ///< Set when -ffunction-sections is enabled
@@ -199,6 +200,7 @@ public:
     EmitDeclMetadata = 0;
     EmitGcovArcs = 0;
     EmitGcovNotes = 0;
+    EmitOpenCLArgMetadata = 0;
     ForbidGuardVariables = 0;
     FunctionSections = 0;
     HiddenWeakTemplateVTables = 0;

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -252,6 +252,33 @@ void CodeGenFunction::EmitMCountInstrumentation() {
   Builder.CreateCall(MCountFn);
 }
 
+// OpenCL v1.2 s5.6.4.6 allows the compiler to store kernel argument
+// information in the program executable. The argument information stored
+// includes the argument name, its type, the address and access qualifiers used.
+// FIXME: Add type, address, and access qualifiers.
+static void GenOpenCLArgMetadata(const FunctionDecl *FD, llvm::Function *Fn,
+                                 CodeGenModule &CGM,llvm::LLVMContext &Context,
+                                 llvm::SmallVector <llvm::Value*, 5> &kernelMDArgs) {
+  
+  // Create MDNodes that represents the kernel arg metadata.
+  // Each MDNode is a list in the form of "key", N number of values which is
+  // the same number of values as their are kernel arguments.
+  
+  // MDNode for the kernel argument names.
+  SmallVector<llvm::Value*, 8> argNames;
+  argNames.push_back(llvm::MDString::get(Context, "kernel_arg_name"));
+  
+  for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
+    const ParmVarDecl *parm = FD->getParamDecl(i);
+    
+    // Get argument name.
+    argNames.push_back(llvm::MDString::get(Context, parm->getName()));
+    
+  }
+  // Add MDNode to the list of all metadata.
+  kernelMDArgs.push_back(llvm::MDNode::get(Context, argNames));
+}
+
 void CodeGenFunction::EmitOpenCLKernelMetadata(const FunctionDecl *FD, 
                                                llvm::Function *Fn)
 {
@@ -263,6 +290,9 @@ void CodeGenFunction::EmitOpenCLKernelMetadata(const FunctionDecl *FD,
   llvm::SmallVector <llvm::Value*, 5> kernelMDArgs;
   kernelMDArgs.push_back(Fn);
 
+  if (CGM.getCodeGenOpts().EmitOpenCLArgMetadata)
+    GenOpenCLArgMetadata(FD, Fn, CGM, Context, kernelMDArgs);
+  
   if (FD->hasAttr<WorkGroupSizeHintAttr>()) {
     llvm::SmallVector <llvm::Value*, 5> attrMDArgs;
     attrMDArgs.push_back(llvm::MDString::get(Context, "work_group_size_hint"));

clang/lib/Frontend/CompilerInvocation.cpp

@@ -210,6 +210,8 @@ static void CodeGenOptsToArgs(const CodeGenOptions &Opts, ToArgsList &Res) {
     Res.push_back("-femit-coverage-data");
   if (Opts.EmitGcovNotes)
     Res.push_back("-femit-coverage-notes");
+  if (Opts.EmitOpenCLArgMetadata)
+    Res.push_back("-cl-kernel-arg-info");
   if (!Opts.MergeAllConstants)
     Res.push_back("-fno-merge-all-constants");
   if (Opts.NoCommon)
@@ -1258,6 +1260,7 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.InstrumentForProfiling = Args.hasArg(OPT_pg);
   Opts.EmitGcovArcs = Args.hasArg(OPT_femit_coverage_data);
   Opts.EmitGcovNotes = Args.hasArg(OPT_femit_coverage_notes);
+  Opts.EmitOpenCLArgMetadata = Args.hasArg(OPT_cl_kernel_arg_info);
   Opts.CoverageFile = Args.getLastArgValue(OPT_coverage_file);
   Opts.DebugCompilationDir = Args.getLastArgValue(OPT_fdebug_compilation_dir);
   Opts.LinkBitcodeFile = Args.getLastArgValue(OPT_mlink_bitcode_file);

clang/test/CodeGenOpenCL/kernel-arg-info.cl

@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 %s -cl-kernel-arg-info -emit-llvm -o - | FileCheck %s
+
+kernel void foo(int *X, int Y, int anotherArg) {
+  *X = Y + anotherArg;
+}
+
+// CHECK: metadata !{metadata !"kernel_arg_name", metadata !"X", metadata !"Y", metadata !"anotherArg"}