Summary:
We define the `__xray_customeevent` builtin that gets translated to
IR calls to the correct intrinsic. The default implementation of this is
a no-op function. The codegen side of this follows the following logic:
- When `-fxray-instrument` is not provided in the driver, we elide all
calls to `__xray_customevent`.
- When `-fxray-instrument` is enabled and a function is marked as "never
instrumented", we elide all calls to `__xray_customevent` in that
function; if either marked as "always instrumented" or subject to
threshold-based instrumentation, we emit a call to the
`llvm.xray.customevent` intrinsic from LLVM for each
`__xray_customevent` occurrence in the function.
This change depends on D27503 (to land in LLVM first).
Reviewers: echristo, rsmith
Subscribers: mehdi_amini, pelikan, lrl, cfe-commits
Differential Revision: https://reviews.llvm.org/D30018
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@302492
91177308-0d34-0410-b5e6-
96231b3b80d8
BUILTIN(__builtin_os_log_format_buffer_size, "zcC*.", "p:0:nut")
BUILTIN(__builtin_os_log_format, "v*v*cC*.", "p:0:nt")
+// Builtins for XRay
+BUILTIN(__xray_customevent, "vcC*z", "")
+
#undef BUILTIN
#undef LIBBUILTIN
#undef LANGBUILTIN
return RValue::get(ConstantInt::get(ConvertType(E->getType()),
Layout.size().getQuantity()));
}
+
+ case Builtin::BI__xray_customevent: {
+ if (!ShouldXRayInstrumentFunction())
+ return RValue::getIgnored();
+ if (const auto *XRayAttr = CurFuncDecl->getAttr<XRayInstrumentAttr>()) {
+ if (XRayAttr->neverXRayInstrument())
+ 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);
+ }
+ auto Arg1 = EmitScalarExpr(E->getArg(1));
+ auto PTy1 = FTy->getParamType(1);
+ if (PTy1 != Arg1->getType())
+ Arg1 = Builder.CreateTruncOrBitCast(Arg1, PTy1);
+ return RValue::get(Builder.CreateCall(F, {Arg0Val, Arg1}));
+ }
}
// If this is an alias for a lib function (e.g. __builtin_sin), emit
--- /dev/null
+// RUN: %clang_cc1 -fxray-instrument -x c++ -std=c++11 -triple x86_64-unknown-unknown -emit-llvm -o - %s | FileCheck %s
+
+// CHECK-LABEL: @_Z16alwaysInstrumentv
+[[clang::xray_always_instrument]] void alwaysInstrument() {
+ static constexpr char kPhase[] = "instrument";
+ __xray_customevent(kPhase, 10);
+ // CHECK: call void @llvm.xray.customevent(i8*{{.*}}, i32 10)
+}
+
+// CHECK-LABEL: @_Z15neverInstrumentv
+[[clang::xray_never_instrument]] void neverInstrument() {
+ static constexpr char kPhase[] = "never";
+ __xray_customevent(kPhase, 5);
+ // CHECK-NOT: call void @llvm.xray.customevent(i8*{{.*}}, i32 5)
+}
+
+// CHECK-LABEL: @_Z21conditionalInstrumenti
+[[clang::xray_always_instrument]] void conditionalInstrument(int v) {
+ static constexpr char kTrue[] = "true";
+ static constexpr char kUntrue[] = "untrue";
+ if (v % 2)
+ __xray_customevent(kTrue, 4);
+ else
+ __xray_customevent(kUntrue, 6);
+
+ // CHECK: call void @llvm.xray.customevent(i8*{{.*}}, i32 4)
+ // CHECK: call void @llvm.xray.customevent(i8*{{.*}}, i32 6)
+}