[profdata] Skip probes with missing counter and function pointers #163254
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@llvm/pr-subscribers-pgo Author: Ellis Hoag (ellishg) ChangesIf an instrumented function is dead-stripped, I believe its debug info can stick around, including annotations for debug info correlation. This can lead to tons of the following errors when merging. If address of the function and the counter cannot be found, we assume it has been dead-stripped, and we skip that probe so we don't emit a warning. To test this (and to test other warnings), I added a test in While I'm here, also fix some style errors. Full diff: https://github.com/llvm/llvm-project/pull/163254.diff 2 Files Affected:
diff --git a/llvm/lib/ProfileData/InstrProfCorrelator.cpp b/llvm/lib/ProfileData/InstrProfCorrelator.cpp
index 07b69e9fad3ec..65fd5ba1c5ad2 100644
--- a/llvm/lib/ProfileData/InstrProfCorrelator.cpp
+++ b/llvm/lib/ProfileData/InstrProfCorrelator.cpp
@@ -25,8 +25,8 @@
using namespace llvm;
/// Get profile section.
-Expected<object::SectionRef> getInstrProfSection(const object::ObjectFile &Obj,
- InstrProfSectKind IPSK) {
+static Expected<object::SectionRef>
+getInstrProfSection(const object::ObjectFile &Obj, InstrProfSectKind IPSK) {
// On COFF, the getInstrProfSectionName returns the section names may followed
// by "$M". The linker removes the dollar and everything after it in the final
// binary. Do the same to match.
@@ -173,11 +173,10 @@ InstrProfCorrelator::get(std::unique_ptr<MemoryBuffer> Buffer,
}
std::optional<size_t> InstrProfCorrelator::getDataSize() const {
- if (auto *C = dyn_cast<InstrProfCorrelatorImpl<uint32_t>>(this)) {
+ if (auto *C = dyn_cast<InstrProfCorrelatorImpl<uint32_t>>(this))
return C->getDataSize();
- } else if (auto *C = dyn_cast<InstrProfCorrelatorImpl<uint64_t>>(this)) {
+ if (auto *C = dyn_cast<InstrProfCorrelatorImpl<uint64_t>>(this))
return C->getDataSize();
- }
return {};
}
@@ -318,9 +317,9 @@ DwarfInstrProfCorrelator<IntPtrT>::getLocation(const DWARFDie &Die) const {
DataExtractor Data(Location.Expr, DICtx->isLittleEndian(), AddressSize);
DWARFExpression Expr(Data, AddressSize);
for (auto &Op : Expr) {
- if (Op.getCode() == dwarf::DW_OP_addr) {
+ if (Op.getCode() == dwarf::DW_OP_addr)
return Op.getRawOperand(0);
- } else if (Op.getCode() == dwarf::DW_OP_addrx) {
+ if (Op.getCode() == dwarf::DW_OP_addrx) {
uint64_t Index = Op.getRawOperand(0);
if (auto SA = DU.getAddrOffsetSectionItem(Index))
return SA->Address;
@@ -352,7 +351,7 @@ void DwarfInstrProfCorrelator<IntPtrT>::correlateProfileDataImpl(
bool UnlimitedWarnings = (MaxWarnings == 0);
// -N suppressed warnings means we can emit up to N (unsuppressed) warnings
int NumSuppressedWarnings = -MaxWarnings;
- auto maybeAddProbe = [&](DWARFDie Die) {
+ auto MaybeAddProbe = [&](DWARFDie Die) {
if (!isDIEOfProbe(Die))
return;
std::optional<const char *> FunctionName;
@@ -385,6 +384,9 @@ void DwarfInstrProfCorrelator<IntPtrT>::correlateProfileDataImpl(
NumCounters = AnnotationFormValue->getAsUnsignedConstant();
}
}
+ // If there is no function and no counter, assume it was dead-stripped
+ if (!FunctionPtr && !CounterPtr)
+ return;
if (!FunctionName || !CFGHash || !CounterPtr || !NumCounters) {
if (UnlimitedWarnings || ++NumSuppressedWarnings < 1) {
WithColor::warning()
@@ -418,7 +420,7 @@ void DwarfInstrProfCorrelator<IntPtrT>::correlateProfileDataImpl(
if (Data) {
InstrProfCorrelator::Probe P;
P.FunctionName = *FunctionName;
- if (auto Name = FnDie.getName(DINameKind::LinkageName))
+ if (const char *Name = FnDie.getName(DINameKind::LinkageName))
P.LinkageName = Name;
P.CFGHash = *CFGHash;
P.CounterOffset = CounterOffset;
@@ -438,10 +440,10 @@ void DwarfInstrProfCorrelator<IntPtrT>::correlateProfileDataImpl(
};
for (auto &CU : DICtx->normal_units())
for (const auto &Entry : CU->dies())
- maybeAddProbe(DWARFDie(CU.get(), &Entry));
+ MaybeAddProbe(DWARFDie(CU.get(), &Entry));
for (auto &CU : DICtx->dwo_units())
for (const auto &Entry : CU->dies())
- maybeAddProbe(DWARFDie(CU.get(), &Entry));
+ MaybeAddProbe(DWARFDie(CU.get(), &Entry));
if (!UnlimitedWarnings && NumSuppressedWarnings > 0)
WithColor::warning() << format("Suppressed %d additional warnings\n",
diff --git a/llvm/test/tools/llvm-profdata/debug-info-correlate-warnings.ll b/llvm/test/tools/llvm-profdata/debug-info-correlate-warnings.ll
new file mode 100644
index 0000000000000..af4d3f65cb9b1
--- /dev/null
+++ b/llvm/test/tools/llvm-profdata/debug-info-correlate-warnings.ll
@@ -0,0 +1,179 @@
+; RUN: split-file %s %t
+; RUN: clang %t/a.ll -o %t/a.out
+; RUN: llvm-profdata merge --debug-info=%t/a.out %t/a.proftext -o %t/a.profdata 2>&1 | FileCheck %s --implicit-check-not=warning
+
+; CHECK: warning: Incomplete DIE for function None:
+; CHECK: warning: Incomplete DIE for function no_cfg: CFGHash=None
+; CHECK: warning: Incomplete DIE for function no_counter: {{.*}} NumCounters=None
+; CHECK: warning: Incomplete DIE for function no_profc: {{.*}} CounterPtr=None
+; CHECK: warning: Could not find address of function no_func
+
+;--- a.proftext
+:ir
+
+;--- a.c
+int main() { return 0; }
+
+void removed() {}
+void no_name() {}
+void no_cfg() {}
+void no_counter() {}
+void no_profc() {}
+void no_func() {}
+;--- gen
+clang --target=x86_64-linux -fprofile-generate -mllvm -debug-info-correlate -S -emit-llvm -g a.c -o -
+# NOTE: After generating the IR below, manually remove the follwing pieces
+# 1. Remove "@removed" function and "@__profc_removed" global
+# 2. Remove "Function Name" annotation for "@no_name"
+# 3. Remove "CFG Hash" annotation for "@no_cfg"
+# 4. Remove "Num Counters" annotation for "@no_counter"
+# 5. Remove "@__profc_no_profc"
+# 6. Remove "@no_func"
+;--- a.ll
+; ModuleID = 'a.c'
+source_filename = "a.c"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux"
+
+$__llvm_profile_raw_version = comdat any
+
+$__profc_main = comdat nodeduplicate
+
+$__profc_removed = comdat nodeduplicate
+
+$__profc_no_name = comdat nodeduplicate
+
+$__profc_no_cfg = comdat nodeduplicate
+
+$__profc_no_counter = comdat nodeduplicate
+
+$__profc_no_profc = comdat nodeduplicate
+
+$__profc_no_func = comdat nodeduplicate
+
+$__llvm_profile_filename = comdat any
+
+@__llvm_profile_raw_version = hidden constant i64 648518346341351434, comdat
+@__profn_main = private constant [4 x i8] c"main"
+@__profn_removed = private constant [7 x i8] c"removed"
+@__profn_no_name = private constant [7 x i8] c"no_name"
+@__profn_no_cfg = private constant [6 x i8] c"no_cfg"
+@__profn_no_counter = private constant [10 x i8] c"no_counter"
+@__profn_no_profc = private constant [8 x i8] c"no_profc"
+@__profn_no_func = private constant [7 x i8] c"no_func"
+@__profc_main = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", comdat, align 8, !dbg !0
+@__profc_no_name = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", comdat, align 8, !dbg !19
+@__profc_no_cfg = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", comdat, align 8, !dbg !24
+@__profc_no_counter = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", comdat, align 8, !dbg !29
+@__profc_no_func = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", comdat, align 8, !dbg !39
+@llvm.compiler.used = appending global [5 x ptr] [ptr @__profc_main, ptr @__profc_no_name, ptr @__profc_no_cfg, ptr @__profc_no_counter, ptr @__profc_no_func], section "llvm.metadata"
+@__llvm_profile_filename = hidden constant [20 x i8] c"default_%m.proflite\00", comdat
+
+; Function Attrs: noinline nounwind optnone uwtable
+define dso_local i32 @main() #0 !dbg !2 {
+ %1 = alloca i32, align 4
+ %2 = load i64, ptr @__profc_main, align 8
+ %3 = add i64 %2, 1
+ store i64 %3, ptr @__profc_main, align 8
+ store i32 0, ptr %1, align 4
+ ret i32 0, !dbg !53
+}
+
+; Function Attrs: noinline nounwind optnone uwtable
+define dso_local void @no_name() #0 !dbg !21 {
+ %1 = load i64, ptr @__profc_no_name, align 8, !dbg !55
+ %2 = add i64 %1, 1, !dbg !55
+ store i64 %2, ptr @__profc_no_name, align 8, !dbg !55
+ ret void, !dbg !55
+}
+
+; Function Attrs: noinline nounwind optnone uwtable
+define dso_local void @no_cfg() #0 !dbg !26 {
+ %1 = load i64, ptr @__profc_no_cfg, align 8, !dbg !56
+ %2 = add i64 %1, 1, !dbg !56
+ store i64 %2, ptr @__profc_no_cfg, align 8, !dbg !56
+ ret void, !dbg !56
+}
+
+; Function Attrs: noinline nounwind optnone uwtable
+define dso_local void @no_counter() #0 !dbg !31 {
+ %1 = load i64, ptr @__profc_no_counter, align 8, !dbg !57
+ %2 = add i64 %1, 1, !dbg !57
+ store i64 %2, ptr @__profc_no_counter, align 8, !dbg !57
+ ret void, !dbg !57
+}
+
+; Function Attrs: noinline nounwind optnone uwtable
+define dso_local void @no_profc() #0 !dbg !36 {
+ ret void, !dbg !58
+}
+
+; Function Attrs: nounwind
+declare void @llvm.instrprof.increment(ptr, i64, i32, i32) #1
+
+attributes #0 = { noinline nounwind optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #1 = { nounwind }
+
+!llvm.dbg.cu = !{!7}
+!llvm.module.flags = !{!46, !47, !48, !49, !50, !51, !52}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "__profc_main", scope: !2, file: !3, type: !14, isLocal: true, isDefinition: true, annotations: !44)
+!2 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 1, type: !4, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !7)
+!3 = !DIFile(filename: "a.c", directory: "/proc/self/cwd", checksumkind: CSK_MD5, checksum: "22eee0eada6e6964fca794aa5a0966d0")
+!4 = !DISubroutineType(types: !5)
+!5 = !{!6}
+!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!7 = distinct !DICompileUnit(language: DW_LANG_C11, file: !3, isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, globals: !8, splitDebugInlining: false, nameTableKind: None)
+!8 = !{!0, !9, !19, !24, !29, !34, !39}
+!9 = !DIGlobalVariableExpression(var: !10, expr: !DIExpression())
+!10 = distinct !DIGlobalVariable(name: "__profc_removed", scope: !11, file: !3, type: !14, isLocal: true, isDefinition: true, annotations: !15)
+!11 = distinct !DISubprogram(name: "removed", scope: !3, file: !3, line: 3, type: !12, scopeLine: 3, spFlags: DISPFlagDefinition, unit: !7)
+!12 = !DISubroutineType(types: !13)
+!13 = !{null}
+!14 = !DIBasicType(tag: DW_TAG_unspecified_type, name: "Profile Data Type")
+!15 = !{!16, !17, !18}
+!16 = !{!"Function Name", !"removed"}
+!17 = !{!"CFG Hash", i64 742261418966908927}
+!18 = !{!"Num Counters", i32 1}
+!19 = !DIGlobalVariableExpression(var: !20, expr: !DIExpression())
+!20 = distinct !DIGlobalVariable(name: "__profc_no_name", scope: !21, file: !3, type: !14, isLocal: true, isDefinition: true, annotations: !22)
+!21 = distinct !DISubprogram(name: "no_name", scope: !3, file: !3, line: 4, type: !12, scopeLine: 4, spFlags: DISPFlagDefinition, unit: !7)
+!22 = !{!17, !18}
+!23 = !{!"Function Name", !"no_name"}
+!24 = !DIGlobalVariableExpression(var: !25, expr: !DIExpression())
+!25 = distinct !DIGlobalVariable(name: "__profc_no_cfg", scope: !26, file: !3, type: !14, isLocal: true, isDefinition: true, annotations: !27)
+!26 = distinct !DISubprogram(name: "no_cfg", scope: !3, file: !3, line: 5, type: !12, scopeLine: 5, spFlags: DISPFlagDefinition, unit: !7)
+!27 = !{!28, !18}
+!28 = !{!"Function Name", !"no_cfg"}
+!29 = !DIGlobalVariableExpression(var: !30, expr: !DIExpression())
+!30 = distinct !DIGlobalVariable(name: "__profc_no_counter", scope: !31, file: !3, type: !14, isLocal: true, isDefinition: true, annotations: !32)
+!31 = distinct !DISubprogram(name: "no_counter", scope: !3, file: !3, line: 6, type: !12, scopeLine: 6, spFlags: DISPFlagDefinition, unit: !7)
+!32 = !{!33, !17}
+!33 = !{!"Function Name", !"no_counter"}
+!34 = !DIGlobalVariableExpression(var: !35, expr: !DIExpression())
+!35 = distinct !DIGlobalVariable(name: "__profc_no_profc", scope: !36, file: !3, type: !14, isLocal: true, isDefinition: true, annotations: !37)
+!36 = distinct !DISubprogram(name: "no_profc", scope: !3, file: !3, line: 7, type: !12, scopeLine: 7, spFlags: DISPFlagDefinition, unit: !7)
+!37 = !{!38, !17, !18}
+!38 = !{!"Function Name", !"no_profc"}
+!39 = !DIGlobalVariableExpression(var: !40, expr: !DIExpression())
+!40 = distinct !DIGlobalVariable(name: "__profc_no_func", scope: !41, file: !3, type: !14, isLocal: true, isDefinition: true, annotations: !42)
+!41 = distinct !DISubprogram(name: "no_func", scope: !3, file: !3, line: 8, type: !12, scopeLine: 8, spFlags: DISPFlagDefinition, unit: !7)
+!42 = !{!43, !17, !18}
+!43 = !{!"Function Name", !"no_func"}
+!44 = !{!45, !17, !18}
+!45 = !{!"Function Name", !"main"}
+!46 = !{i32 7, !"Dwarf Version", i32 5}
+!47 = !{i32 2, !"Debug Info Version", i32 3}
+!48 = !{i32 1, !"wchar_size", i32 4}
+!49 = !{i32 8, !"PIC Level", i32 2}
+!50 = !{i32 7, !"PIE Level", i32 2}
+!51 = !{i32 7, !"uwtable", i32 2}
+!52 = !{i32 7, !"frame-pointer", i32 2}
+!53 = !DILocation(line: 1, column: 14, scope: !2)
+!54 = !DILocation(line: 3, column: 17, scope: !11)
+!55 = !DILocation(line: 4, column: 17, scope: !21)
+!56 = !DILocation(line: 5, column: 16, scope: !26)
+!57 = !DILocation(line: 6, column: 20, scope: !31)
+!58 = !DILocation(line: 7, column: 18, scope: !36)
+!59 = !DILocation(line: 8, column: 17, scope: !41)
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If an instrumented function is dead-stripped, I believe its debug info can stick around, including annotations for debug info correlation. This can lead to tons of the following errors when merging.
If address of the function and the counter cannot be found, we assume it has been dead-stripped, and we skip that probe so we don't emit a warning. To test this (and to test other warnings), I added a test in
tools/llvm-profdatato compile some LLVM IR down to a binary and runllvm-profdata mergeto correlate the binary. To emulate dead-stripping and problems, I manually deleted some debug annotations.While I'm here, also fix some style errors.