Index: compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
===================================================================
--- compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
+++ compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
@@ -26,25 +26,15 @@
/* Declare section start and stop symbols for various sections
* generated by compiler instrumentation.
*/
-extern __llvm_profile_data PROF_DATA_START COMPILER_RT_VISIBILITY;
-extern __llvm_profile_data PROF_DATA_STOP COMPILER_RT_VISIBILITY;
-extern uint64_t PROF_CNTS_START COMPILER_RT_VISIBILITY;
-extern uint64_t PROF_CNTS_STOP COMPILER_RT_VISIBILITY;
-extern uint32_t PROF_ORDERFILE_START COMPILER_RT_VISIBILITY;
-extern char PROF_NAME_START COMPILER_RT_VISIBILITY;
-extern char PROF_NAME_STOP COMPILER_RT_VISIBILITY;
-extern ValueProfNode PROF_VNODES_START COMPILER_RT_VISIBILITY;
-extern ValueProfNode PROF_VNODES_STOP COMPILER_RT_VISIBILITY;
-
-/* Add dummy data to ensure the section is always created. */
-__llvm_profile_data
- __prof_data_sect_data[0] COMPILER_RT_SECTION(INSTR_PROF_DATA_SECT_NAME);
-uint64_t
- __prof_cnts_sect_data[0] COMPILER_RT_SECTION(INSTR_PROF_CNTS_SECT_NAME);
-uint32_t
- __prof_orderfile_sect_data[0] COMPILER_RT_SECTION(INSTR_PROF_ORDERFILE_SECT_NAME);
-char __prof_nms_sect_data[0] COMPILER_RT_SECTION(INSTR_PROF_NAME_SECT_NAME);
-ValueProfNode __prof_vnodes_sect_data[0] COMPILER_RT_SECTION(INSTR_PROF_VNODES_SECT_NAME);
+extern __llvm_profile_data PROF_DATA_START COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
+extern __llvm_profile_data PROF_DATA_STOP COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
+extern uint64_t PROF_CNTS_START COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
+extern uint64_t PROF_CNTS_STOP COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
+extern uint32_t PROF_ORDERFILE_START COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
+extern char PROF_NAME_START COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
+extern char PROF_NAME_STOP COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
+extern ValueProfNode PROF_VNODES_START COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
+extern ValueProfNode PROF_VNODES_STOP COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
COMPILER_RT_VISIBILITY const __llvm_profile_data *
__llvm_profile_begin_data(void) {
Index: compiler-rt/test/profile/instrprof-gc-sections.c
===================================================================
--- /dev/null
+++ compiler-rt/test/profile/instrprof-gc-sections.c
@@ -0,0 +1,91 @@
+// REQUIRES: linux, lld-available
+
+// RUN: %clang_profgen=%t.profraw -fuse-ld=lld -fcoverage-mapping -mllvm -enable-name-compression=false -DCODE=1 -ffunction-sections -fdata-sections -Wl,--gc-sections -o %t %s
+// RUN: %run %t
+// RUN: llvm-profdata merge -o %t.profdata %t.profraw
+// RUN: llvm-profdata show --all-functions %t.profdata | FileCheck %s -check-prefix=PROF
+// RUN: llvm-cov show %t -instr-profile %t.profdata | FileCheck %s -check-prefix=COV
+// RUN: llvm-nm %t | FileCheck %s -check-prefix=NM
+// RUN: llvm-readelf -x __llvm_prf_names %t | FileCheck %s -check-prefix=PRF_NAMES
+// RUN: llvm-readelf -x __llvm_prf_cnts %t | FileCheck %s -check-prefix=PRF_CNTS
+
+// RUN: %clang_lto_profgen=%t.lto.profraw -fuse-ld=lld -fcoverage-mapping -mllvm -enable-name-compression=false -DCODE=1 -ffunction-sections -fdata-sections -Wl,--gc-sections -flto -o %t.lto %s
+// RUN: %run %t.lto
+// RUN: llvm-profdata merge -o %t.lto.profdata %t.lto.profraw
+// RUN: llvm-profdata show --all-functions %t.lto.profdata | FileCheck %s -check-prefix=PROF
+// RUN: llvm-cov show %t.lto -instr-profile %t.lto.profdata | FileCheck %s -check-prefix=COV
+// RUN: llvm-nm %t.lto | FileCheck %s -check-prefix=NM
+// RUN: llvm-readelf -x __llvm_prf_names %t.lto | FileCheck %s -check-prefix=PRF_NAMES
+// RUN: llvm-readelf -x __llvm_prf_cnts %t.lto | FileCheck %s -check-prefix=PRF_CNTS
+
+// Note: We expect foo() and some of the profiling data associated with it to
+// be garbage collected.
+
+// Note: When there is no code in a program, we expect to see the exact same
+// set of external functions provided by the profile runtime.
+
+// RUN: %clang_profgen -fcoverage-mapping -ffunction-sections -fdata-sections -Wl,--gc-sections -shared -o %t.nocode.so %s
+// RUN: llvm-nm -jgU %t.nocode.so | grep -vE "__start_.*|__stop_.*" > %t.nocode.syms
+// RUN: llvm-nm -jgU %t | grep -vE "main|foo|_start|__libc_.*" > %t.code.syms
+// RUN: diff %t.nocode.syms %t.code.syms
+
+// Note: We also check the IR instrumentation and expect foo() to be garbage
+// collected as well.
+
+// RUN: %clang_pgogen=%t.pgo.profraw -fuse-ld=lld -DCODE=1 -ffunction-sections -fdata-sections -Wl,--gc-sections -o %t.pgo %s
+// RUN: %run %t.pgo
+// RUN: llvm-profdata merge -o %t.pgo.profdata %t.pgo.profraw
+// RUN: llvm-profdata show --all-functions %t.pgo.profdata | FileCheck %s -check-prefix=PGO
+// RUN: llvm-nm %t.pgo | FileCheck %s -check-prefix=NM
+
+#ifdef CODE
+
+// COV: [[@LINE+1]]{{ *}}|{{ *}}0|void foo()
+void foo() {}
+
+// COV: [[@LINE+1]]{{ *}}|{{ *}}1|int main
+int main() { return 0; }
+
+#endif // CODE
+
+// NM-NOT: foo
+
+// PROF: Counters:
+// PROF-NEXT: main:
+// PROF-NEXT: Hash:
+// PROF-NEXT: Counters: 1
+// PROF-NEXT: Function count: 1
+// PROF-NEXT: Instrumentation level: Front-end
+// PROF-NEXT: Functions shown: 1
+// PROF-NEXT: Total functions: 1
+// PROF-NEXT: Maximum function count:
+// PROF-NEXT: Maximum internal block count:
+
+// Note: We don't expect the names of garbage collected functions to disappear
+// from __llvm_prf_names, because collectPGOFuncNameStrings() glues the names
+// together.
+
+// PRF_NAMES: Hex dump of section '__llvm_prf_names':
+// PRF_NAMES-NEXT: {{.*}} 0800666f 6f016d61 696e {{.*$}}
+// | | f o o # m a i n
+// | |___________|
+// | |
+// UncompressedLen = 8 |
+// |
+// CompressedLen = 0
+
+// Note: We expect the profile counters for garbage collected functions to also
+// be garbage collected.
+
+// PRF_CNTS: Hex dump of section '__llvm_prf_cnts':
+// PRF_CNTS-NEXT: {{.*}} 00000000 00000000 {{.*$}}
+
+// PGO: Counters:
+// PGO-NEXT: main:
+// PGO-NEXT: Hash:
+// PGO-NEXT: Counters: 1
+// PGO-NEXT: Instrumentation level: IR
+// PGO-NEXT: Functions shown: 1
+// PGO-NEXT: Total functions: 1
+// PGO-NEXT: Maximum function count:
+// PGO-NEXT: Maximum internal block count:
Index: llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -844,6 +844,8 @@
CounterPtr->setAlignment(Align(8));
MaybeSetComdat(CounterPtr);
CounterPtr->setLinkage(Linkage);
+ CounterPtr->setMetadata(LLVMContext::MD_associated,
+ MDNode::get(Ctx, ValueAsMetadata::get(CounterPtr)));
auto *Int8PtrTy = Type::getInt8PtrTy(Ctx);
// Allocate statically the array of pointers to value profile nodes for
@@ -865,6 +867,8 @@
getInstrProfSectionName(IPSK_vals, TT.getObjectFormat()));
ValuesVar->setAlignment(Align(8));
MaybeSetComdat(ValuesVar);
+ ValuesVar->setMetadata(LLVMContext::MD_associated,
+ MDNode::get(Ctx, ValueAsMetadata::get(CounterPtr)));
ValuesPtrExpr =
ConstantExpr::getBitCast(ValuesVar, Type::getInt8PtrTy(Ctx));
}
@@ -899,6 +903,8 @@
Data->setAlignment(Align(INSTR_PROF_DATA_ALIGNMENT));
MaybeSetComdat(Data);
Data->setLinkage(Linkage);
+ Data->setMetadata(LLVMContext::MD_associated,
+ MDNode::get(Ctx, ValueAsMetadata::get(CounterPtr)));
PD.RegionCounters = CounterPtr;
PD.DataVar = Data;
Index: llvm/test/Instrumentation/InstrProfiling/associated.ll
===================================================================
--- /dev/null
+++ llvm/test/Instrumentation/InstrProfiling/associated.ll
@@ -0,0 +1,18 @@
+; RUN: opt < %s -pgo-instr-gen -instrprof -S | FileCheck %s
+; RUN: opt < %s -passes=pgo-instr-gen,instrprof -S | FileCheck %s
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@__profn_foo = hidden constant [3 x i8] c"foo"
+
+; CHECK: @__profc_foo = hidden global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", align 8, !associated !0
+; CHECK: @__profd_foo = hidden global {{.*}}, section "__llvm_prf_data", align 8, !associated !0
+
+define void @foo() {
+ call void @llvm.instrprof.increment(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @__profn_foo, i32 0, i32 0), i64 0, i32 1, i32 0)
+ ret void
+}
+
+declare void @llvm.instrprof.increment(i8*, i64, i32, i32)
+
+; CHECK: !0 = !{[1 x i64]* @__profc_foo}
Index: llvm/test/Transforms/PGOProfile/counter_promo.ll
===================================================================
--- llvm/test/Transforms/PGOProfile/counter_promo.ll
+++ llvm/test/Transforms/PGOProfile/counter_promo.ll
@@ -60,7 +60,8 @@
; ATOMIC_PROMO: atomicrmw add {{.*}} @__profc_foo{{.*}}0), i64 %[[LIVEOUT1]] seq_cst
; ATOMIC_PROMO-NEXT: atomicrmw add {{.*}} @__profc_foo{{.*}}1), i64 %[[LIVEOUT2]] seq_cst
; ATOMIC_PROMO-NEXT: atomicrmw add {{.*}} @__profc_foo{{.*}}2), i64 %[[LIVEOUT3]] seq_cst
-; PROMO-NOT: @__profc_foo
+; PROMO-NOT: @__profc_foo{{.*}})
+
}
Index: llvm/test/Transforms/PGOProfile/counter_promo_mexits.ll
===================================================================
--- llvm/test/Transforms/PGOProfile/counter_promo_mexits.ll
+++ llvm/test/Transforms/PGOProfile/counter_promo_mexits.ll
@@ -69,7 +69,8 @@
; PROMO-NEXT: %pgocount{{.*}} = load {{.*}} @__profc_foo{{.*}} 4)
; PROMO-NEXT: add
; PROMO-NEXT: store {{.*}}@__profc_foo{{.*}}4)
-; PROMO-NOT: @__profc_foo
+; PROMO-NOT: @__profc_foo{{.*}})
+
bb15: ; preds = %bb14, %bb4