anchuraj · anchuraj · Apr 30, 2025 · Apr 29, 2025
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
@@ -2811,10 +2811,12 @@ def finput_charset_EQ : Joined<["-"], "finput-charset=">,
   Visibility<[ClangOption, FlangOption, FC1Option]>, Group<f_Group>,
   HelpText<"Specify the default character set for source files">;
 def fexec_charset_EQ : Joined<["-"], "fexec-charset=">, Group<f_Group>;
-def finstrument_functions : Flag<["-"], "finstrument-functions">, Group<f_Group>,
-  Visibility<[ClangOption, CC1Option]>,
-  HelpText<"Generate calls to instrument function entry and exit">,
-  MarshallingInfoFlag<CodeGenOpts<"InstrumentFunctions">>;
+def finstrument_functions
+    : Flag<["-"], "finstrument-functions">,
+      Group<f_Group>,
+      Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>,
+      HelpText<"Generate calls to instrument function entry and exit">,
+      MarshallingInfoFlag<CodeGenOpts<"InstrumentFunctions">>;
 def finstrument_functions_after_inlining : Flag<["-"], "finstrument-functions-after-inlining">, Group<f_Group>,
   Visibility<[ClangOption, CC1Option]>,
   HelpText<"Like -finstrument-functions, but insert the calls after inlining">,

diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -128,7 +128,8 @@ void Flang::addOtherOptions(const ArgList &Args, ArgStringList &CmdArgs) const {
                    options::OPT_std_EQ, options::OPT_W_Joined,
                    options::OPT_fconvert_EQ, options::OPT_fpass_plugin_EQ,
                    options::OPT_funderscoring, options::OPT_fno_underscoring,
-                   options::OPT_funsigned, options::OPT_fno_unsigned});
+                   options::OPT_funsigned, options::OPT_fno_unsigned,
+                   options::OPT_finstrument_functions});
 
   llvm::codegenoptions::DebugInfoKind DebugInfoKind;
   if (Args.hasArg(options::OPT_gN_Group)) {

diff --git a/flang/include/flang/Frontend/CodeGenOptions.h b/flang/include/flang/Frontend/CodeGenOptions.h
@@ -81,6 +81,8 @@ class CodeGenOptions : public CodeGenOptionsBase {
   /// Options to add to the linker for the object file
   std::vector<std::string> DependentLibs;
 
+  bool InstrumentFunctions{false};
+
   // The RemarkKind enum class and OptRemark struct are identical to what Clang
   // has
   // TODO: Share with clang instead of re-implementing here

diff --git a/flang/include/flang/Optimizer/Transforms/Passes.td b/flang/include/flang/Optimizer/Transforms/Passes.td
@@ -393,6 +393,14 @@ def FunctionAttr : Pass<"function-attr", "mlir::func::FuncOp"> {
             clEnumValN(mlir::LLVM::framePointerKind::FramePointerKind::All, "All", ""),
             clEnumValN(mlir::LLVM::framePointerKind::FramePointerKind::Reserved, "Reserved", "")
           )}]>,
+       Option<"instrumentFunctionEntry", "instrument-function-entry",
+              "std::string", /*default=*/"",
+              "Sets the name of the profiling function called during function "
+              "entry">,
+       Option<"instrumentFunctionExit", "instrument-function-exit",
+              "std::string", /*default=*/"",
+              "Sets the name of the profiling function called during function "
+              "exit">,
        Option<"noInfsFPMath", "no-infs-fp-math", "bool", /*default=*/"false",
               "Set the no-infs-fp-math attribute on functions in the module.">,
        Option<"noNaNsFPMath", "no-nans-fp-math", "bool", /*default=*/"false",

diff --git a/flang/include/flang/Tools/CrossToolHelpers.h b/flang/include/flang/Tools/CrossToolHelpers.h
@@ -102,13 +102,17 @@ struct MLIRToLLVMPassPipelineConfig : public FlangEPCallBacks {
     UnsafeFPMath = mathOpts.getAssociativeMath() &&
         mathOpts.getReciprocalMath() && NoSignedZerosFPMath &&
         ApproxFuncFPMath && mathOpts.getFPContractEnabled();
+    if (opts.InstrumentFunctions) {
+      InstrumentFunctionsEntry = "__cyg_profile_func_enter";
+      InstrumentFunctionsExit = "__cyg_profile_func_exit";
+    }
   }
 
   llvm::OptimizationLevel OptLevel; ///< optimisation level
   bool StackArrays = false; ///< convert memory allocations to alloca.
   bool Underscoring = true; ///< add underscores to function names.
   bool LoopVersioning = false; ///< Run the version loop pass.
-  bool AliasAnalysis = false; ///< Add TBAA tags to generated LLVMIR
+  bool AliasAnalysis = false; ///< Add TBAA tags to generated LLVMIR.
   llvm::codegenoptions::DebugInfoKind DebugInfo =
       llvm::codegenoptions::NoDebugInfo; ///< Debug info generation.
   llvm::FramePointerKind FramePointerKind =
@@ -124,6 +128,8 @@ struct MLIRToLLVMPassPipelineConfig : public FlangEPCallBacks {
   bool UnsafeFPMath = false; ///< Set unsafe-fp-math attribute for functions.
   bool NSWOnLoopVarInc = true; ///< Add nsw flag to loop variable increments.
   bool EnableOpenMP = false; ///< Enable OpenMP lowering.
+  std::string InstrumentFunctionsEntry = "";
+  std::string InstrumentFunctionsExit = "";
 };
 
 struct OffloadModuleOpts {

diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -310,6 +310,10 @@ static void parseCodeGenArgs(Fortran::frontend::CodeGenOptions &opts,
        args.filtered(clang::driver::options::OPT_fembed_offload_object_EQ))
     opts.OffloadObjects.push_back(a->getValue());
 
+  if (args.hasFlag(clang::driver::options::OPT_finstrument_functions,
+                   clang::driver::options::OPT_finstrument_functions, false))
+    opts.InstrumentFunctions = true;
+
   // -flto=full/thin option.
   if (const llvm::opt::Arg *a =
           args.getLastArg(clang::driver::options::OPT_flto_EQ)) {

diff --git a/flang/lib/Optimizer/Passes/Pipelines.cpp b/flang/lib/Optimizer/Passes/Pipelines.cpp
@@ -341,7 +341,8 @@ void createDefaultFIRCodeGenPassPipeline(mlir::PassManager &pm,
     framePointerKind = mlir::LLVM::framePointerKind::FramePointerKind::None;
 
   pm.addPass(fir::createFunctionAttr(
-      {framePointerKind, config.NoInfsFPMath, config.NoNaNsFPMath,
+      {framePointerKind, config.InstrumentFunctionsEntry,
+       config.InstrumentFunctionsExit, config.NoInfsFPMath, config.NoNaNsFPMath,
        config.ApproxFuncFPMath, config.NoSignedZerosFPMath, config.UnsafeFPMath,
        ""}));
 

diff --git a/flang/lib/Optimizer/Transforms/FunctionAttr.cpp b/flang/lib/Optimizer/Transforms/FunctionAttr.cpp
@@ -28,6 +28,8 @@ namespace {
 class FunctionAttrPass : public fir::impl::FunctionAttrBase<FunctionAttrPass> {
 public:
   FunctionAttrPass(const fir::FunctionAttrOptions &options) {
+    instrumentFunctionEntry = options.instrumentFunctionEntry;
+    instrumentFunctionExit = options.instrumentFunctionExit;
     framePointerKind = options.framePointerKind;
     noInfsFPMath = options.noInfsFPMath;
     noNaNsFPMath = options.noNaNsFPMath;
@@ -72,6 +74,14 @@ void FunctionAttrPass::runOnOperation() {
 
   auto llvmFuncOpName =
       mlir::OperationName(mlir::LLVM::LLVMFuncOp::getOperationName(), context);
+  if (!instrumentFunctionEntry.empty())
+    func->setAttr(mlir::LLVM::LLVMFuncOp::getInstrumentFunctionEntryAttrName(
+                      llvmFuncOpName),
+                  mlir::StringAttr::get(context, instrumentFunctionEntry));
+  if (!instrumentFunctionExit.empty())
+    func->setAttr(mlir::LLVM::LLVMFuncOp::getInstrumentFunctionExitAttrName(
+                      llvmFuncOpName),
+                  mlir::StringAttr::get(context, instrumentFunctionExit));
   if (noInfsFPMath)
     func->setAttr(
         mlir::LLVM::LLVMFuncOp::getNoInfsFpMathAttrName(llvmFuncOpName),

diff --git a/flang/test/Driver/func-attr-instrument-functions.f90 b/flang/test/Driver/func-attr-instrument-functions.f90
@@ -0,0 +1,9 @@
+! RUN: %flang -O1 -finstrument-functions -emit-llvm -S -o - %s 2>&1| FileCheck %s
+
+subroutine func
+end subroutine func
+
+! CHECK: define void @func_()
+! CHECK: {{.*}}call void @__cyg_profile_func_enter(ptr {{.*}}@func_, ptr {{.*}})
+! CHECK: {{.*}}call void @__cyg_profile_func_exit(ptr {{.*}}@func_, ptr {{.*}})
+! CHECK-NEXT: ret {{.*}}