[XRay][clang] Add flag to choose instrumentation bundles

[dberris]

Summary

This change addresses http://llvm.org/PR36926 by allowing users to pick
which instrumentation bundles to use, when instrumenting with XRay. In
particular, the flag -fxray-instrumentation-bundle= has four valid
values:

• all: the default, emits all instrumentation kinds
• none: equivalent to -fnoxray-instrument
• function: emits the entry/exit instrumentation
• custom: emits the custom event instrumentation

These can be combined either as comma-separated values, or as
repeated flag values.

[echristo]

clang/include/clang/Frontend/CodeGenOptions.h

114

"function" might spell easier? :)

clang/lib/CodeGen/CGBuiltin.cpp

3355

I'd probably spell this code like the block above it rather than this.

clang/lib/Driver/XRayArgs.cpp

60–61

Extraneous reformat.

85

How about a more descriptive name here and a string switch below?

clang/lib/Frontend/CompilerInvocation.cpp

453

StringSwitch maybe?

[pelikan]

I would probably add more tests for the different configurations, but I suspect more diffs are coming after this.

clang/include/clang/Driver/Options.td

1124

I'd suggest making them "fn-only" and "custom-only", or just plain "function" and "custom".

1124

I also don't get why "none" is an option here, if it's equivalent to -fnoxray-instrument. Why duplicate the functionality and add more points the users will have to debug?

clang/include/clang/Frontend/CodeGenOptions.h

111

To me, this feels like a bitfield would be a better match.
All = Function | Custom
None = 0

clang/lib/Driver/XRayArgs.cpp

61

I would also print the triple. Something like:

"-fomit-bugs is not supported on target win64-ppc-none"

will be much more informative, especially when you collect logs from build machines on lots of architectures (like Linux distro/BSD package builders do).

85

+1

[dberris]

• fixup: address comments

clang/include/clang/Frontend/CodeGenOptions.h

111

Thought about that, but the ergonomics from the user-side isn't as good. Having to know about which kinds of sleds specifically to enable seems much harder to explain. Using bundles that we control from the beginning keeps this much simpler.

clang/lib/CodeGen/CGBuiltin.cpp

3355

The codegen options don't work like pointers, and we can't use C++17 if initialisers yet. Would have loved this to be:

if (auto XRayBundle = ...; XRayBundle == ... || XRayBundle == ...)
  return RValue::getIgnored();

Removed the scoping instead.

clang/lib/Driver/XRayArgs.cpp

61

Probably not today. Good idea though, could be a different patch.

[dberris]

• fixup: Fix tests for better coverage of settings

[echristo]

clang/include/clang/Frontend/CodeGenOptions.h

111

I dunno, I think I agree with the other commenter. This feels awkward.

clang/lib/CodeGen/CGBuiltin.cpp

3351

Break this out into some sort of function to determine which one we want? We do this a couple times.

[dberris]

• Rebase
• Address comments to use a bitmask/bitset for instrumentation bundle

[pelikan]

Most of my comments are minor enough I'd be OK if this went in. But please consider them before committing.

clang/include/clang/Driver/XRayArgs.h

28

Since the class already has "XRay" in its name, I would rename the member to just "InstrumentationBundle", just as most of the other members are.

clang/include/clang/Frontend/CodeGenOptions.h

111

Now I fail to spot where is this enum used. IIUC this should work even when it's not here, as the code uses the things in namespace XRayInstrKind.

clang/lib/CodeGen/CodeGenFunction.cpp

469

typo: builin -> builtin

471–474

I kind of don't like how the "-fxray-instrument" variable is called "XRayInstrumentFunctions" because that's not what it means any more. I think in a later diff, we should clean this up. Or maybe even clean up some of the old flags whose functionality has been superseded by this. But the logic here is fine.

Same with the misleading "ShouldXRayInstrumentFunction()" which controls custom events too, and not just functions.

clang/lib/Driver/XRayArgs.cpp

107–109

nitpick: I'd rewrite it to

if (!Valid) {
  D.Diag
  continue; // or break or return
}

<stuff if Valid below>

but the current code logic is fine.

clang/lib/Frontend/CompilerInvocation.cpp

457

did you mean: "(Mask == None)"?

[dberris]

• fixup: Address comments

[dberris]

Thanks, Martin! Landing now, after suggested changes.

clang/lib/CodeGen/CodeGenFunction.cpp

471–474

Good point. Yes, we could make this cleaner.

clang/include/clang/Basic/XRayInstr.h

+//===--- XRayInstr.h --------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// \brief Defines the clang::XRayInstrKind enum.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_BASIC_XRAYINSTR_H
+#define LLVM_CLANG_BASIC_XRAYINSTR_H
+
+#include "clang/Basic/LLVM.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/MathExtras.h"
+#include <cassert>
+#include <cstdint>
+
+namespace clang {
+
+using XRayInstrMask = uint32_t;
+
+namespace XRayInstrKind {
+
+// TODO: Auto-generate these as we add more instrumentation kinds.
+enum XRayInstrOrdinal : XRayInstrMask {
+  XRIO_Function,
+  XRIO_Custom,
+  XRIO_Count
+};
+
+constexpr XRayInstrMask None = 0;
+constexpr XRayInstrMask Function = 1U << XRIO_Function;
+constexpr XRayInstrMask Custom = 1U << XRIO_Custom;
+constexpr XRayInstrMask All = Function | Custom;
+
+} // namespace XRayInstrKind
+
+struct XRayInstrSet {
+  bool has(XRayInstrMask K) const {
+    assert(llvm::isPowerOf2_32(K));
+    return Mask & K;
+  }
+
+  bool hasOneOf(XRayInstrMask K) const { return Mask & K; }
+
+  void set(XRayInstrMask K, bool Value) {
+    assert(llvm::isPowerOf2_32(K));
+    Mask = Value ? (Mask | K) : (Mask & ~K);
+  }
+
+  void clear(XRayInstrMask K = XRayInstrKind::All) { Mask &= ~K; }
+
+  bool empty() const { return Mask == 0; }
+
+  XRayInstrMask Mask = 0;
+};
+
+XRayInstrMask parseXRayInstrValue(StringRef Value);
+
+} // namespace clang
+
+#endif // LLVM_CLANG_BASIC_XRAYINSTR_H

clang/include/clang/Driver/Options.td

 def fxray_always_emit_customevents : Flag<["-"], "fxray-always-emit-customevents">, Group<f_Group>,
   Flags<[CC1Option]>,
   HelpText<"Determine whether to always emit __xray_customevent(...) calls even if the function it appears in is not always instrumented.">;
 def fnoxray_always_emit_customevents : Flag<["-"], "fno-xray-always-emit-customevents">, Group<f_Group>,
   Flags<[CC1Option]>;
 
 def fxray_link_deps : Flag<["-"], "fxray-link-deps">, Group<f_Group>,
   Flags<[CC1Option]>,
   HelpText<"Tells clang to add the link dependencies for XRay.">;
 def fnoxray_link_deps : Flag<["-"], "fnoxray-link-deps">, Group<f_Group>,
   Flags<[CC1Option]>;
 
+def fxray_instrumentation_bundle :
+  JoinedOrSeparate<["-"], "fxray-instrumentation-bundle=">,
+  Group<f_Group>, Flags<[CC1Option]>,
+  HelpText<"Select which XRay instrumentation points to emit. Options: all, none, function, custom. Default is 'all'.">;
+
 def ffine_grained_bitfield_accesses : Flag<["-"],
   "ffine-grained-bitfield-accesses">, Group<f_clang_Group>, Flags<[CC1Option]>,
   HelpText<"Use separate accesses for bitfields with legal widths and alignments.">;
 def fno_fine_grained_bitfield_accesses : Flag<["-"],
   "fno-fine-grained-bitfield-accesses">, Group<f_clang_Group>, Flags<[CC1Option]>,
   HelpText<"Use large-integer access for consecutive bitfield runs.">;
 
 def flat__namespace : Flag<["-"], "flat_namespace">;

clang/include/clang/Driver/XRayArgs.h

 //===--- XRayArgs.h - Arguments for XRay ------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 #ifndef LLVM_CLANG_DRIVER_XRAYARGS_H
 #define LLVM_CLANG_DRIVER_XRAYARGS_H
 
+#include "clang/Basic/XRayInstr.h"
 #include "clang/Driver/Types.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Option/ArgList.h"
 
 namespace clang {
 namespace driver {
 
 class ToolChain;
 
 class XRayArgs {
   std::vector<std::string> AlwaysInstrumentFiles;
   std::vector<std::string> NeverInstrumentFiles;
   std::vector<std::string> AttrListFiles;
   std::vector<std::string> ExtraDeps;
   std::vector<std::string> Modes;
+  XRayInstrSet InstrumentationBundle;
   bool XRayInstrument = false;
   int InstructionThreshold = 200;
   bool XRayAlwaysEmitCustomEvents = false;
   bool XRayRT = true;
 
 public:
   /// Parses the XRay arguments from an argument list.
   XRayArgs(const ToolChain &TC, const llvm::opt::ArgList &Args);
   void addArgs(const ToolChain &TC, const llvm::opt::ArgList &Args,
                llvm::opt::ArgStringList &CmdArgs, types::ID InputType) const;
 
   bool needsXRayRt() const { return XRayInstrument && XRayRT; }
   llvm::ArrayRef<std::string> modeList() const { return Modes; }
-
+  XRayInstrSet instrumentationBundle() const { return InstrumentationBundle; }
 };
 
 } // namespace driver
 } // namespace clang
 
 #endif // LLVM_CLANG_DRIVER_XRAYARGS_H

clang/include/clang/Frontend/CodeGenOptions.h

 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_FRONTEND_CODEGENOPTIONS_H
 #define LLVM_CLANG_FRONTEND_CODEGENOPTIONS_H
 
 #include "clang/Basic/DebugInfoOptions.h"
 #include "clang/Basic/Sanitizers.h"
+#include "clang/Basic/XRayInstr.h"
 #include "llvm/Support/CodeGen.h"
 #include "llvm/Support/Regex.h"
 #include "llvm/Target/TargetOptions.h"
 #include <map>
 #include <memory>
 #include <string>
 #include <vector>
 
public:
 
   enum EmbedBitcodeKind {
     Embed_Off,      // No embedded bitcode.
     Embed_All,      // Embed both bitcode and commandline in the output.
     Embed_Bitcode,  // Embed just the bitcode in the output.
     Embed_Marker    // Embed a marker as a placeholder for bitcode.
   };
 
   /// The code model to use (-mcmodel).
   std::string CodeModel;
 
   /// The filename with path we use for coverage data files. The runtime
   /// allows further manipulation with the GCOV_PREFIX and GCOV_PREFIX_STRIP
   /// environment variables.
   std::string CoverageDataFile;
 
   /// The filename with path we use for coverage notes files.
   std::string CoverageNotesFile;
 
   /// The version string to put into coverage files.
public:
 
   std::vector<std::string> Reciprocals;
 
   /// The preferred width for auto-vectorization transforms. This is intended to
   /// override default transforms based on the width of the architected vector
   /// registers.
   std::string PreferVectorWidth;
 
+  /// Set of XRay instrumentation kinds to emit.
+  XRayInstrSet XRayInstrumentationBundle;
+
 public:
   // Define accessors/mutators for code generation options of enumeration type.
 #define CODEGENOPT(Name, Bits, Default)
 #define ENUM_CODEGENOPT(Name, Type, Bits, Default) \
   Type get##Name() const { return static_cast<Type>(Name); } \
   void set##Name(Type Value) { Name = static_cast<unsigned>(Value); }
 #include "clang/Frontend/CodeGenOptions.def"
 

clang/lib/Basic/CMakeLists.txt

add_clang_library(clangBasic
   Targets/WebAssembly.cpp
   Targets/X86.cpp
   Targets/XCore.cpp
   TokenKinds.cpp
   Version.cpp
   VersionTuple.cpp
   VirtualFileSystem.cpp
   Warnings.cpp
+  XRayInstr.cpp
   XRayLists.cpp
   ${version_inc}
   )
 

clang/lib/Basic/XRayInstr.cpp

+//===--- XRayInstr.cpp ------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is part of XRay, a function call instrumentation system.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/XRayInstr.h"
+#include "llvm/ADT/StringSwitch.h"
+
+namespace clang {
+
+XRayInstrMask parseXRayInstrValue(StringRef Value) {
+  XRayInstrMask ParsedKind = llvm::StringSwitch<XRayInstrMask>(Value)
+                                 .Case("all", XRayInstrKind::All)
+                                 .Case("custom", XRayInstrKind::Custom)
+                                 .Case("function", XRayInstrKind::Function)
+                                 .Case("none", XRayInstrKind::None)
+                                 .Default(XRayInstrKind::None);
+  return ParsedKind;
+}
+
+} // namespace clang

clang/lib/CodeGen/CGBuiltin.cpp

case Builtin::BI__builtin_os_log_format_buffer_size: {
     analyze_os_log::computeOSLogBufferLayout(CGM.getContext(), E, Layout);
     return RValue::get(ConstantInt::get(ConvertType(E->getType()),
                                         Layout.size().getQuantity()));
   }
 
   case Builtin::BI__xray_customevent: {
     if (!ShouldXRayInstrumentFunction())
       return RValue::getIgnored();
+
+    if (!CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
+            XRayInstrKind::Custom))
+      return RValue::getIgnored();
+
     if (const auto *XRayAttr = CurFuncDecl->getAttr<XRayInstrumentAttr>())
       if (XRayAttr->neverXRayInstrument() && !AlwaysEmitXRayCustomEvents())
         return RValue::getIgnored();
 
     Function *F = CGM.getIntrinsic(Intrinsic::xray_customevent);
     auto FTy = F->getFunctionType();
     auto Arg0 = E->getArg(0);
     auto Arg0Val = EmitScalarExpr(Arg0);
     auto Arg0Ty = Arg0->getType();
     auto PTy0 = FTy->getParamType(0);
     if (PTy0 != Arg0Val->getType()) {
       if (Arg0Ty->isArrayType())
         Arg0Val = EmitArrayToPointerDecay(Arg0).getPointer();
       else
         Arg0Val = Builder.CreatePointerCast(Arg0Val, PTy0);

clang/lib/CodeGen/CodeGenFunction.cpp

 
 /// ShouldXRayInstrument - Return true if the current function should be
 /// instrumented with XRay nop sleds.
 bool CodeGenFunction::ShouldXRayInstrumentFunction() const {
   return CGM.getCodeGenOpts().XRayInstrumentFunctions;
 }
 
 /// AlwaysEmitXRayCustomEvents - Return true if we should emit IR for calls to
 /// the __xray_customevent(...) builin calls, when doing XRay instrumentation.
 bool CodeGenFunction::AlwaysEmitXRayCustomEvents() const {
-  return CGM.getCodeGenOpts().XRayAlwaysEmitCustomEvents;
+  return CGM.getCodeGenOpts().XRayInstrumentFunctions &&
+         (CGM.getCodeGenOpts().XRayAlwaysEmitCustomEvents ||
+          CGM.getCodeGenOpts().XRayInstrumentationBundle.Mask ==
+              XRayInstrKind::Custom);
 }
 
 llvm::Constant *
 CodeGenFunction::EncodeAddrForUseInPrologue(llvm::Function *F,
                                             llvm::Constant *Addr) {
   // Addresses stored in prologue data can't require run-time fixups and must
   // be PC-relative. Run-time fixups are undesirable because they necessitate
   // writable text segments, which are unsafe. And absolute addresses are
#undef SANITIZER
   // from void* to T* before object initialization completes. Don't match on the
   // namespace because not all allocators are in std::
   if (D && SanOpts.has(SanitizerKind::CFIUnrelatedCast)) {
     if (matchesStlAllocatorFn(D, getContext()))
       SanOpts.Mask &= ~SanitizerKind::CFIUnrelatedCast;
   }
 
   // Apply xray attributes to the function (as a string, for now)
-  bool InstrumentXray = ShouldXRayInstrumentFunction();
+  bool InstrumentXray = ShouldXRayInstrumentFunction() &&
+                        CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
+                            XRayInstrKind::Function);
   if (D && InstrumentXray) {
     if (const auto *XRayAttr = D->getAttr<XRayInstrumentAttr>()) {
       if (XRayAttr->alwaysXRayInstrument())
         Fn->addFnAttr("function-instrument", "xray-always");
       if (XRayAttr->neverXRayInstrument())
         Fn->addFnAttr("function-instrument", "xray-never");
       if (const auto *LogArgs = D->getAttr<XRayLogArgsAttr>()) {
         Fn->addFnAttr("xray-log-args",

clang/lib/CodeGen/CodeGenModule.cpp

bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV,
   }
   return false;
 }
 
 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
                                    StringRef Category) const {
   if (!LangOpts.XRayInstrument)
     return false;
+
   const auto &XRayFilter = getContext().getXRayFilter();
   using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
-  auto Attr = XRayFunctionFilter::ImbueAttribute::NONE;
+  auto Attr = ImbueAttr::NONE;
   if (Loc.isValid())
     Attr = XRayFilter.shouldImbueLocation(Loc, Category);
   if (Attr == ImbueAttr::NONE)
     Attr = XRayFilter.shouldImbueFunction(Fn->getName());
   switch (Attr) {
   case ImbueAttr::NONE:
     return false;
   case ImbueAttr::ALWAYS:

clang/lib/Driver/XRayArgs.cpp

if (Triple.getOS() == llvm::Triple::Linux) {
       }
     } else if (Triple.getOS() == llvm::Triple::FreeBSD ||
                Triple.getOS() == llvm::Triple::OpenBSD) {
       if (Triple.getArch() != llvm::Triple::x86_64) {
         D.Diag(diag::err_drv_clang_unsupported)
             << (std::string(XRayInstrumentOption) + " on " + Triple.str());
       }
     } else {
       D.Diag(diag::err_drv_clang_unsupported)
-          << (std::string(XRayInstrumentOption) +
-              " on non-supported target OS");
+          << (std::string(XRayInstrumentOption) + " on " + Triple.str());
     }
     XRayInstrument = true;
     if (const Arg *A =
             Args.getLastArg(options::OPT_fxray_instruction_threshold_,
                             options::OPT_fxray_instruction_threshold_EQ)) {
       StringRef S = A->getValue();
       if (S.getAsInteger(0, InstructionThreshold) || InstructionThreshold < 0)
         D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;
     }
 
     // By default, the back-end will not emit the lowering for XRay customevent
     // calls if the function is not instrumented. In the future we will change
     // this default to be the reverse, but in the meantime we're going to
     // introduce the new functionality behind a flag.
     if (Args.hasFlag(options::OPT_fxray_always_emit_customevents,
                      options::OPT_fnoxray_always_emit_customevents, false))
       XRayAlwaysEmitCustomEvents = true;
 
     if (!Args.hasFlag(options::OPT_fxray_link_deps,
                       options::OPT_fnoxray_link_deps, true))
       XRayRT = false;
 
+    auto Bundles =
+        Args.getAllArgValues(options::OPT_fxray_instrumentation_bundle);
+    if (Bundles.empty())
+      InstrumentationBundle.Mask = XRayInstrKind::All;
+    else
+      for (const auto &B : Bundles) {
+        llvm::SmallVector<StringRef, 2> BundleParts;
+        llvm::SplitString(B, BundleParts, ",");
+        for (const auto &P : BundleParts) {
+          // TODO: Automate the generation of the string case table.
+          auto Valid = llvm::StringSwitch<bool>(P)
+                           .Cases("none", "all", "function", "custom", true)
+                           .Default(false);
+
+          if (!Valid) {
+            D.Diag(clang::diag::err_drv_invalid_value)
+                << "-fxray-instrumentation-bundle=" << P;
+            continue;
+          }
+
+          auto Mask = parseXRayInstrValue(P);
+          if (Mask == XRayInstrKind::None) {
+            InstrumentationBundle.clear();
+            break;
+          }
+
+          InstrumentationBundle.Mask |= Mask;
+        }
+      }
+
     // Validate the always/never attribute files. We also make sure that they
     // are treated as actual dependencies.
     for (const auto &Filename :
          Args.getAllArgValues(options::OPT_fxray_always_instrument)) {
       if (llvm::sys::fs::exists(Filename)) {
         AlwaysInstrumentFiles.push_back(Filename);
         ExtraDeps.push_back(Filename);
       } else
void XRayArgs::addArgs(const ToolChain &TC, const ArgList &Args,
   }
 
   for (const auto &Never : NeverInstrumentFiles) {
     SmallString<64> NeverInstrumentOpt("-fxray-never-instrument=");
     NeverInstrumentOpt += Never;
     CmdArgs.push_back(Args.MakeArgString(NeverInstrumentOpt));
   }
 
-  for (const auto& AttrFile : AttrListFiles) {
+  for (const auto &AttrFile : AttrListFiles) {
     SmallString<64> AttrListFileOpt("-fxray-attr-list=");
     AttrListFileOpt += AttrFile;
     CmdArgs.push_back(Args.MakeArgString(AttrListFileOpt));
   }
 
   for (const auto &Dep : ExtraDeps) {
     SmallString<64> ExtraDepOpt("-fdepfile-entry=");
     ExtraDepOpt += Dep;
     CmdArgs.push_back(Args.MakeArgString(ExtraDepOpt));
   }
 }

clang/lib/Frontend/CompilerInvocation.cpp

 #include "clang/Basic/ObjCRuntime.h"
 #include "clang/Basic/Sanitizers.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/TargetOptions.h"
 #include "clang/Basic/Version.h"
 #include "clang/Basic/VersionTuple.h"
 #include "clang/Basic/VirtualFileSystem.h"
 #include "clang/Basic/Visibility.h"
+#include "clang/Basic/XRayInstr.h"
 #include "clang/Config/config.h"
 #include "clang/Driver/DriverDiagnostic.h"
 #include "clang/Driver/Options.h"
 #include "clang/Frontend/CodeGenOptions.h"
 #include "clang/Frontend/CommandLineSourceLoc.h"
 #include "clang/Frontend/DependencyOutputOptions.h"
 #include "clang/Frontend/FrontendDiagnostic.h"
 #include "clang/Frontend/FrontendOptions.h"

 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Process.h"
 #include "llvm/Support/Regex.h"
+#include "llvm/Support/ScopedPrinter.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetOptions.h"
-#include "llvm/Support/ScopedPrinter.h"
 #include <algorithm>
 #include <atomic>
 #include <cassert>
 #include <cstddef>
 #include <cstring>
 #include <memory>
 #include <string>
 #include <tuple>
for (const auto &Sanitizer : Sanitizers) {
     SanitizerMask K = parseSanitizerValue(Sanitizer, /*AllowGroups=*/false);
     if (K == 0)
       Diags.Report(diag::err_drv_invalid_value) << FlagName << Sanitizer;
     else
       S.set(K, true);
   }
 }
 
+static void parseXRayInstrumentationBundle(StringRef FlagName, StringRef Bundle,
+                                           ArgList &Args, DiagnosticsEngine &D,
+                                           XRayInstrSet &S) {
+  llvm::SmallVector<StringRef, 2> BundleParts;
+  llvm::SplitString(Bundle, BundleParts, ",");
+  for (const auto B : BundleParts) {
+    auto Mask = parseXRayInstrValue(B);
+    if (Mask == XRayInstrKind::None)
+      if (B != "none")
+        D.Report(diag::err_drv_invalid_value) << FlagName << Bundle;
+      else
+        S.Mask = Mask;
+    else if (Mask == XRayInstrKind::All)
+      S.Mask = Mask;
+    else
+      S.set(Mask, true);
+  }
+}
+
 // Set the profile kind for fprofile-instrument.
 static void setPGOInstrumentor(CodeGenOptions &Opts, ArgList &Args,
                                DiagnosticsEngine &Diags) {
   Arg *A = Args.getLastArg(OPT_fprofile_instrument_EQ);
   if (A == nullptr)
     return;
   StringRef S = A->getValue();
   unsigned I = llvm::StringSwitch<unsigned>(S)
static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   }
 
   Opts.PreserveVec3Type = Args.hasArg(OPT_fpreserve_vec3_type);
   Opts.InstrumentFunctions = Args.hasArg(OPT_finstrument_functions);
   Opts.InstrumentFunctionsAfterInlining =
       Args.hasArg(OPT_finstrument_functions_after_inlining);
   Opts.InstrumentFunctionEntryBare =
       Args.hasArg(OPT_finstrument_function_entry_bare);
-  Opts.XRayInstrumentFunctions = Args.hasArg(OPT_fxray_instrument);
+
+  Opts.XRayInstrumentFunctions =
+      Args.hasArg(OPT_fxray_instrument);
   Opts.XRayAlwaysEmitCustomEvents =
       Args.hasArg(OPT_fxray_always_emit_customevents);
   Opts.XRayInstructionThreshold =
       getLastArgIntValue(Args, OPT_fxray_instruction_threshold_EQ, 200, Diags);
+
+  auto XRayInstrBundles =
+      Args.getAllArgValues(OPT_fxray_instrumentation_bundle);
+  if (XRayInstrBundles.empty())
+    Opts.XRayInstrumentationBundle.Mask = XRayInstrKind::All;
+  else
+    for (const auto &A : XRayInstrBundles)
+      parseXRayInstrumentationBundle("-fxray-instrumentation-bundle=", A, Args,
+                                     Diags, Opts.XRayInstrumentationBundle);
+
   Opts.InstrumentForProfiling = Args.hasArg(OPT_pg);
   Opts.CallFEntry = Args.hasArg(OPT_mfentry);
   Opts.EmitOpenCLArgMetadata = Args.hasArg(OPT_cl_kernel_arg_info);
 
   if (const Arg *A = Args.getLastArg(OPT_fcf_protection_EQ)) {
     StringRef Name = A->getValue();
     if (Name == "full") {
       Opts.CFProtectionReturn = 1;

clang/test/CodeGen/xray-instrumentation-bundles.cpp

+// RUN: %clang_cc1 -fxray-instrument -fxray-instrumentation-bundle=none -x c++ \
+// RUN:     -std=c++11 -triple x86_64-unknown-unknown -emit-llvm -o - %s \
+// RUN:     | FileCheck --check-prefixes CHECK,NOFUNCTION,NOCUSTOM %s
+// RUN: %clang_cc1 -fxray-instrument \
+// RUN:     -fxray-instrumentation-bundle=function -x c++ \
+// RUN:     -std=c++11 -triple x86_64-unknown-unknown -emit-llvm -o - %s \
+// RUN:     | FileCheck --check-prefixes CHECK,FUNCTION,NOCUSTOM %s
+// RUN: %clang_cc1 -fxray-instrument \
+// RUN:     -fxray-instrumentation-bundle=custom -x c++ \
+// RUN:     -std=c++11 -triple x86_64-unknown-unknown -emit-llvm -o - %s \
+// RUN:     | FileCheck --check-prefixes CHECK,NOFUNCTION,CUSTOM %s
+// RUN: %clang_cc1 -fxray-instrument \
+// RUN:     -fxray-instrumentation-bundle=function,custom -x c++ \
+// RUN:     -std=c++11 -triple x86_64-unknown-unknown -emit-llvm -o - %s \
+// RUN:     | FileCheck --check-prefixes CHECK,FUNCTION,CUSTOM %s
+// RUN: %clang_cc1 -fxray-instrument \
+// RUN:     -fxray-instrumentation-bundle=function \
+// RUN:     -fxray-instrumentation-bundle=custom -x c++ \
+// RUN:     -std=c++11 -triple x86_64-unknown-unknown -emit-llvm -o - %s \
+// RUN:     | FileCheck --check-prefixes CHECK,FUNCTION,CUSTOM %s
+
+// CHECK: define void @_Z16alwaysInstrumentv() #[[ALWAYSATTR:[0-9]+]] {
+[[clang::xray_always_instrument]] void alwaysInstrument() {
+  static constexpr char kPhase[] = "always";
+  __xray_customevent(kPhase, 6);
+  // CUSTOM: call void @llvm.xray.customevent(i8*{{.*}}, i32 6)
+  // NOCUSTOM-NOT: call void @llvm.xray.customevent(i8*{{.*}}, i32 6)
+}
+
+// FUNCTION: attributes #[[ALWAYSATTR]] = {{.*}} "function-instrument"="xray-always" {{.*}}
+// NOFUNCTION-NOT: attributes #[[ALWAYSATTR]] = {{.*}} "function-instrument"="xray-always" {{.*}}