dberris created this revision.
dberris added reviewers: echristo, kpw, eizan, pelikan.
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, which will emit all kinds of instrumentation
points.
- `none`: equivalent to -fnoxray-instrument
- `function-extents`: only emits the entry/exit sleds
- `custom-only`: only emits the custom event sleds
https://reviews.llvm.org/D44970
Files:
clang/include/clang/Driver/Options.td
clang/include/clang/Driver/XRayArgs.h
clang/include/clang/Frontend/CodeGenOptions.def
clang/include/clang/Frontend/CodeGenOptions.h
clang/lib/CodeGen/CGBuiltin.cpp
clang/lib/Driver/XRayArgs.cpp
clang/lib/Frontend/CompilerInvocation.cpp
clang/test/CodeGen/xray-instrumentation-bundles.cpp
Index: clang/test/CodeGen/xray-instrumentation-bundles.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGen/xray-instrumentation-bundles.cpp
@@ -0,0 +1,14 @@
+// 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 %s
+// RUN: %clang_cc1 -fxray-instrument \
+// RUN: -fxray-instrumentation-bundle=function-extents -x c++ \
+// RUN: -std=c++11 -triple x86_64-unknown-unknown -emit-llvm -o - %s \
+// RUN: | FileCheck %s
+
+// CHECK-LABEL: alwaysInstrument
+[[clang::xray_always_instrument]] void alwaysInstrument() {
+ static constexpr char kPhase[] = "always";
+ __xray_customevent(kPhase, 6);
+ // CHECK-NOT: call void @llvm.xray.customevent(i8*{{.*}}, i32 6)
+}
Index: clang/lib/Frontend/CompilerInvocation.cpp
===================================================================
--- clang/lib/Frontend/CompilerInvocation.cpp
+++ clang/lib/Frontend/CompilerInvocation.cpp
@@ -446,6 +446,21 @@
}
}
+static CodeGenOptions::XRayInstrumentationPointBundle
+parseXRayInstrumentationBundle(Arg *A, ArgList &Args, DiagnosticsEngine &D) {
+ StringRef V = A->getValue();
+ if (V == "all")
+ return CodeGenOptions::XRayInstrumentationPointBundle::XRay_All;
+ if (V == "none")
+ return CodeGenOptions::XRayInstrumentationPointBundle::XRay_None;
+ if (V == "function-extents")
+ return CodeGenOptions::XRayInstrumentationPointBundle::XRay_FunctionExtents;
+ if (V == "custom-only")
+ return CodeGenOptions::XRayInstrumentationPointBundle::XRay_CustomOnly;
+ D.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << V;
+ return CodeGenOptions::XRayInstrumentationPointBundle::XRay_All;
+}
+
// Set the profile kind for fprofile-instrument.
static void setPGOInstrumentor(CodeGenOptions &Opts, ArgList &Args,
DiagnosticsEngine &Diags) {
@@ -853,6 +868,11 @@
Args.hasArg(OPT_fxray_always_emit_customevents);
Opts.XRayInstructionThreshold =
getLastArgIntValue(Args, OPT_fxray_instruction_threshold_EQ, 200, Diags);
+
+ if (auto A = Args.getLastArg(OPT_fxray_instrumentation_bundle))
+ Opts.setXRayInstrumentationBundle(
+ parseXRayInstrumentationBundle(A, Args, Diags));
+
Opts.InstrumentForProfiling = Args.hasArg(OPT_pg);
Opts.CallFEntry = Args.hasArg(OPT_mfentry);
Opts.EmitOpenCLArgMetadata = Args.hasArg(OPT_cl_kernel_arg_info);
Index: clang/lib/Driver/XRayArgs.cpp
===================================================================
--- clang/lib/Driver/XRayArgs.cpp
+++ clang/lib/Driver/XRayArgs.cpp
@@ -27,6 +27,8 @@
constexpr char XRayInstrumentOption[] = "-fxray-instrument";
constexpr char XRayInstructionThresholdOption[] =
"-fxray-instruction-threshold=";
+constexpr char XRayInstrumentationBundleOption[] =
+ "-fxray-instrumentation-bundle=";
} // namespace
XRayArgs::XRayArgs(const ToolChain &TC, const ArgList &Args) {
@@ -50,13 +52,14 @@
<< (std::string(XRayInstrumentOption) + " on " + Triple.str());
}
} else if (Triple.getOS() == llvm::Triple::FreeBSD) {
- if (Triple.getArch() != llvm::Triple::x86_64) {
- D.Diag(diag::err_drv_clang_unsupported)
- << (std::string(XRayInstrumentOption) + " on " + Triple.str());
- }
+ 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 non-supported target OS");
}
XRayInstrument = true;
if (const Arg *A =
@@ -75,6 +78,19 @@
options::OPT_fnoxray_always_emit_customevents, false))
XRayAlwaysEmitCustomEvents = true;
+ // We check the bundle of instrumentation that we let users choose. This
+ // coarse grained control is used to determine which instrumentation points
+ // to actually emit.
+ if (const Arg *A =
+ Args.getLastArg(options::OPT_fxray_instrumentation_bundle)) {
+ StringRef B = A->getValue();
+ if (B != "all" && B != "none" && B != "function-extents" &&
+ B != "custom-only")
+ D.Diag(diag::err_drv_invalid_value) << A->getAsString(Args) << B;
+ else
+ XRayBundle = B;
+ }
+
// Validate the always/never attribute files. We also make sure that they
// are treated as actual dependencies.
for (const auto &Filename :
@@ -109,6 +125,8 @@
CmdArgs.push_back(Args.MakeArgString(Twine(XRayInstructionThresholdOption) +
Twine(InstructionThreshold)));
+ CmdArgs.push_back(Args.MakeArgString(Twine(XRayInstrumentationBundleOption) +
+ Twine(XRayBundle)));
for (const auto &Always : AlwaysInstrumentFiles) {
SmallString<64> AlwaysInstrumentOpt("-fxray-always-instrument=");
Index: clang/lib/CodeGen/CGBuiltin.cpp
===================================================================
--- clang/lib/CodeGen/CGBuiltin.cpp
+++ clang/lib/CodeGen/CGBuiltin.cpp
@@ -3243,6 +3243,15 @@
if (XRayAttr->neverXRayInstrument() && !AlwaysEmitXRayCustomEvents())
return RValue::getIgnored();
+ // Check first whether the bundle of XRay instrumentation includes this
+ // custom events.
+ {
+ auto XRayBundle = CGM.getCodeGenOpts().getXRayInstrumentationBundle();
+ if (XRayBundle == CodeGenOptions::XRay_None ||
+ XRayBundle == CodeGenOptions::XRay_FunctionExtents)
+ return RValue::getIgnored();
+ }
+
Function *F = CGM.getIntrinsic(Intrinsic::xray_customevent);
auto FTy = F->getFunctionType();
auto Arg0 = E->getArg(0);
Index: clang/include/clang/Frontend/CodeGenOptions.h
===================================================================
--- clang/include/clang/Frontend/CodeGenOptions.h
+++ clang/include/clang/Frontend/CodeGenOptions.h
@@ -107,6 +107,14 @@
Embed_Marker // Embed a marker as a placeholder for bitcode.
};
+ enum XRayInstrumentationPointBundle {
+ XRay_All, // Always emit all the instrumentation points.
+ XRay_None, // Emit none of the instrumentation points.
+ XRay_FunctionExtents, // Only emit function entry/exit instrumentation
+ // points.
+ XRay_CustomOnly, // Only emit custom event instrumentation points.
+ };
+
/// The code model to use (-mcmodel).
std::string CodeModel;
Index: clang/include/clang/Frontend/CodeGenOptions.def
===================================================================
--- clang/include/clang/Frontend/CodeGenOptions.def
+++ clang/include/clang/Frontend/CodeGenOptions.def
@@ -95,6 +95,10 @@
///< Set when -fxray-always-emit-customevents is enabled.
CODEGENOPT(XRayAlwaysEmitCustomEvents , 1, 0)
+///< Filter the instrumentation points we emit, to predefined groupings.
+ENUM_CODEGENOPT(XRayInstrumentationBundle, XRayInstrumentationPointBundle, 4,
+ XRayInstrumentationPointBundle::XRay_All)
+
///< Set the minimum number of instructions in a function to determine selective
///< XRay instrumentation.
VALUE_CODEGENOPT(XRayInstructionThreshold , 32, 200)
Index: clang/include/clang/Driver/XRayArgs.h
===================================================================
--- clang/include/clang/Driver/XRayArgs.h
+++ clang/include/clang/Driver/XRayArgs.h
@@ -25,6 +25,7 @@
bool XRayInstrument = false;
int InstructionThreshold = 200;
bool XRayAlwaysEmitCustomEvents = false;
+ std::string XRayBundle = "all";
public:
/// Parses the XRay arguments from an argument list.
Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -1107,6 +1107,10 @@
def fnoxray_always_emit_customevents : Flag<["-"], "fno-xray-always-emit-customevents">, Group<f_Group>,
Flags<[CC1Option]>;
+def fxray_instrumentation_bundle : Joined<["-"], "fxray-instrumentation-bundle=">,
+ Group<f_Group>, Flags<[CC1Option]>,
+ HelpText<"Select which bundle of XRay instrumentation points to emit. Options: all, none, function-extents, custom-only.">;
+
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.">;
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