dberris created this revision. dberris added reviewers: mboerger, eizan. Herald added subscribers: dexonsmith, mehdi_amini.
Before this change, we only emit the XRay attributes in LLVM IR when the -fxray-instrument flag is provided. This may cause issues with thinlto when the final binary is being built/linked with -fxray-instrument, and the constitutent LLVM IR gets re-lowered with xray instrumentation. With this change, we can honour the attributes provided in the source code and preserve those in the IR. This way, even in thinlto builds, we retain the attributes which say whether functions should never be XRay instrumented, or whether they must always be XRay instrumented. This change addresses llvm.org/PR38922. https://reviews.llvm.org/D52015 Files: clang/lib/CodeGen/CodeGenFunction.cpp clang/lib/CodeGen/CodeGenModule.cpp clang/test/CodeGen/xray-attributes-supported.cpp Index: clang/test/CodeGen/xray-attributes-supported.cpp =================================================================== --- clang/test/CodeGen/xray-attributes-supported.cpp +++ clang/test/CodeGen/xray-attributes-supported.cpp @@ -6,6 +6,18 @@ // RUN: %clang_cc1 %s -fxray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mips64el-unknown-linux-gnu | FileCheck %s // RUN: %clang_cc1 %s -fxray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple powerpc64le-unknown-linux-gnu | FileCheck %s +// We also want to ensure that the attributes show up even if we explicitly turn +// off XRay instrumentation. We let the back-end decide whether to honour the +// attributes instead. +// +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple x86_64-unknown-linux-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple arm-unknown-linux-gnu -target-abi apcs-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mips-unknown-linux-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mipsel-unknown-linux-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mips64-unknown-linux-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mips64el-unknown-linux-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple powerpc64le-unknown-linux-gnu | FileCheck %s + // Make sure that the LLVM attribute for XRay-annotated functions do show up. [[clang::xray_always_instrument]] void foo() { // CHECK: define void @_Z3foov() #0 Index: clang/lib/CodeGen/CodeGenModule.cpp =================================================================== --- clang/lib/CodeGen/CodeGenModule.cpp +++ clang/lib/CodeGen/CodeGenModule.cpp @@ -1967,9 +1967,6 @@ 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 = ImbueAttr::NONE; Index: clang/lib/CodeGen/CodeGenFunction.cpp =================================================================== --- clang/lib/CodeGen/CodeGenFunction.cpp +++ clang/lib/CodeGen/CodeGenFunction.cpp @@ -901,21 +901,20 @@ } // Apply xray attributes to the function (as a string, for now) - bool InstrumentXray = ShouldXRayInstrumentFunction() && - CGM.getCodeGenOpts().XRayInstrumentationBundle.has( - XRayInstrKind::Function); - if (D && InstrumentXray) { + if (D) { 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", - llvm::utostr(LogArgs->getArgumentCount())); + if (CGM.getCodeGenOpts().XRayInstrumentationBundle.has( + XRayInstrKind::Function)) { + 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", + llvm::utostr(LogArgs->getArgumentCount())); } } else { - if (!CGM.imbueXRayAttrs(Fn, Loc)) + if (ShouldXRayInstrumentFunction() && !CGM.imbueXRayAttrs(Fn, Loc)) Fn->addFnAttr( "xray-instruction-threshold", llvm::itostr(CGM.getCodeGenOpts().XRayInstructionThreshold));
Index: clang/test/CodeGen/xray-attributes-supported.cpp =================================================================== --- clang/test/CodeGen/xray-attributes-supported.cpp +++ clang/test/CodeGen/xray-attributes-supported.cpp @@ -6,6 +6,18 @@ // RUN: %clang_cc1 %s -fxray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mips64el-unknown-linux-gnu | FileCheck %s // RUN: %clang_cc1 %s -fxray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple powerpc64le-unknown-linux-gnu | FileCheck %s +// We also want to ensure that the attributes show up even if we explicitly turn +// off XRay instrumentation. We let the back-end decide whether to honour the +// attributes instead. +// +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple x86_64-unknown-linux-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple arm-unknown-linux-gnu -target-abi apcs-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mips-unknown-linux-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mipsel-unknown-linux-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mips64-unknown-linux-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple mips64el-unknown-linux-gnu | FileCheck %s +// RUN: %clang_cc1 %s -fno-xray-instrument -std=c++11 -x c++ -emit-llvm -o - -triple powerpc64le-unknown-linux-gnu | FileCheck %s + // Make sure that the LLVM attribute for XRay-annotated functions do show up. [[clang::xray_always_instrument]] void foo() { // CHECK: define void @_Z3foov() #0 Index: clang/lib/CodeGen/CodeGenModule.cpp =================================================================== --- clang/lib/CodeGen/CodeGenModule.cpp +++ clang/lib/CodeGen/CodeGenModule.cpp @@ -1967,9 +1967,6 @@ 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 = ImbueAttr::NONE; Index: clang/lib/CodeGen/CodeGenFunction.cpp =================================================================== --- clang/lib/CodeGen/CodeGenFunction.cpp +++ clang/lib/CodeGen/CodeGenFunction.cpp @@ -901,21 +901,20 @@ } // Apply xray attributes to the function (as a string, for now) - bool InstrumentXray = ShouldXRayInstrumentFunction() && - CGM.getCodeGenOpts().XRayInstrumentationBundle.has( - XRayInstrKind::Function); - if (D && InstrumentXray) { + if (D) { 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", - llvm::utostr(LogArgs->getArgumentCount())); + if (CGM.getCodeGenOpts().XRayInstrumentationBundle.has( + XRayInstrKind::Function)) { + 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", + llvm::utostr(LogArgs->getArgumentCount())); } } else { - if (!CGM.imbueXRayAttrs(Fn, Loc)) + if (ShouldXRayInstrumentFunction() && !CGM.imbueXRayAttrs(Fn, Loc)) Fn->addFnAttr( "xray-instruction-threshold", llvm::itostr(CGM.getCodeGenOpts().XRayInstructionThreshold));
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