diff --git a/compiler-rt/test/profile/Linux/instrprof-value-merge-lld.c b/compiler-rt/test/profile/Linux/instrprof-value-merge-lld.c --- a/compiler-rt/test/profile/Linux/instrprof-value-merge-lld.c +++ b/compiler-rt/test/profile/Linux/instrprof-value-merge-lld.c @@ -1,7 +1,7 @@ // REQUIRES: lld-available /// Test ld with GC. -// RUN: %clang_pgogen -o %t -O3 %S/Inputs/instrprof-value-merge.c -fuse-ld=lld -ffunction-sections -fdata-sections -Wl,--gc-sections +// RUN: %clang_pgogen -o %t -O3 %S/Inputs/instrprof-value-merge.c -fuse-ld=lld -ffunction-sections -fdata-sections -Wl,--gc-sections -z start-stop-gc // RUN: rm -rf %t.profdir // RUN: env LLVM_PROFILE_FILE=%t.profdir/default_%m.profraw %run %t // RUN: env LLVM_PROFILE_FILE=%t.profdir/default_%m.profraw %run %t diff --git a/llvm/include/llvm/Transforms/Instrumentation/InstrProfiling.h b/llvm/include/llvm/Transforms/Instrumentation/InstrProfiling.h --- a/llvm/include/llvm/Transforms/Instrumentation/InstrProfiling.h +++ b/llvm/include/llvm/Transforms/Instrumentation/InstrProfiling.h @@ -57,6 +57,7 @@ } }; DenseMap ProfileDataMap; + std::vector CompilerUsedVars; std::vector UsedVars; std::vector ReferencedNames; GlobalVariable *NamesVar; diff --git a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp --- a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp +++ b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp @@ -539,6 +539,7 @@ NamesVar = nullptr; NamesSize = 0; ProfileDataMap.clear(); + CompilerUsedVars.clear(); UsedVars.clear(); TT = Triple(M.getTargetTriple()); @@ -921,7 +922,7 @@ ProfileDataMap[NamePtr] = PD; // Mark the data variable as used so that it isn't stripped out. - UsedVars.push_back(Data); + CompilerUsedVars.push_back(Data); // Now that the linkage set by the FE has been passed to the data and counter // variables, reset Name variable's linkage and visibility to private so that // it can be removed later by the compiler. @@ -976,6 +977,8 @@ Constant::getNullValue(VNodesTy), getInstrProfVNodesVarName()); VNodesVar->setSection( getInstrProfSectionName(IPSK_vnodes, TT.getObjectFormat())); + // VNodesVar is used by runtime but not referenced via relocation by other + // sections. Conservatively make it linker retained. UsedVars.push_back(VNodesVar); } @@ -1004,6 +1007,8 @@ // linker from inserting padding before the start of the names section or // between names entries. NamesVar->setAlignment(Align(1)); + // NamesVar is used by runtime but not referenced via relocation by other + // sections. Conservatively make it linker retained. UsedVars.push_back(NamesVar); for (auto *NamePtr : ReferencedNames) @@ -1031,6 +1036,9 @@ getInstrProfRegFuncName(), M); IRBuilder<> IRB(BasicBlock::Create(M->getContext(), "", RegisterF)); + for (Value *Data : CompilerUsedVars) + if (!isa(Data)) + IRB.CreateCall(RuntimeRegisterF, IRB.CreateBitCast(Data, VoidPtrTy)); for (Value *Data : UsedVars) if (Data != NamesVar && !isa(Data)) IRB.CreateCall(RuntimeRegisterF, IRB.CreateBitCast(Data, VoidPtrTy)); @@ -1081,7 +1089,7 @@ IRB.CreateRet(Load); // Mark the user variable as used so that it isn't stripped out. - UsedVars.push_back(User); + CompilerUsedVars.push_back(User); return true; } @@ -1094,9 +1102,14 @@ // or discarded as a unit, so llvm.compiler.used is sufficient. Otherwise, // conservatively make all of them retained by the linker. if (TT.isOSBinFormatELF()) - appendToCompilerUsed(*M, UsedVars); + appendToCompilerUsed(*M, CompilerUsedVars); else - appendToUsed(*M, UsedVars); + appendToUsed(*M, CompilerUsedVars); + + // We do not add proper references from used metadata sections to NamesVar and + // VNodesVar, so we have to be conservative and place them in llvm.used + // regardless of the target, + appendToUsed(*M, UsedVars); } void InstrProfiling::emitInitialization() { diff --git a/llvm/test/Instrumentation/InstrProfiling/icall.ll b/llvm/test/Instrumentation/InstrProfiling/icall.ll --- a/llvm/test/Instrumentation/InstrProfiling/icall.ll +++ b/llvm/test/Instrumentation/InstrProfiling/icall.ll @@ -50,6 +50,12 @@ ; DYN-NOT: @__profvp_foo ; DYN-NOT: @__llvm_prf_vnodes +;; __llvm_prf_vnodes and __llvm_prf_nm are not referenced by other metadata sections. +;; We have to conservatively place them in llvm.used. +; STATIC: @llvm.used = appending global +; STATIC-SAME: @__llvm_prf_vnodes +; STATIC-SAME: @__llvm_prf_nm + ; STATIC: call void @__llvm_profile_instrument_target(i64 %3, i8* bitcast ({ i64, i64, i64*, i8*, i8*, i32, [2 x i16] }* @__profd_foo to i8*), i32 0) ; STATIC-EXT: call void @__llvm_profile_instrument_target(i64 %3, i8* bitcast ({ i64, i64, i64*, i8*, i8*, i32, [2 x i16] }* @__profd_foo to i8*), i32 zeroext 0) ; STATIC-SEXT: call void @__llvm_profile_instrument_target(i64 %3, i8* bitcast ({ i64, i64, i64*, i8*, i8*, i32, [2 x i16] }* @__profd_foo to i8*), i32 signext 0)