[Profile] Refactor profile correlation. #70856
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@llvm/pr-subscribers-pgo Author: Zequan Wu (ZequanWu) ChangesRefactor some code from #69493. #70712 was reverted due to linking failures. So, I removed Patch is 21.43 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/70856.diff 11 Files Affected:
diff --git a/compiler-rt/lib/profile/InstrProfiling.c b/compiler-rt/lib/profile/InstrProfiling.c
index da04d8ebdec95bb..7d69e37815c948f 100644
--- a/compiler-rt/lib/profile/InstrProfiling.c
+++ b/compiler-rt/lib/profile/InstrProfiling.c
@@ -89,3 +89,7 @@ COMPILER_RT_VISIBILITY void __llvm_profile_reset_counters(void) {
}
lprofSetProfileDumped(0);
}
+
+inline int hasCorrelation() {
+ return (__llvm_profile_get_version() & VARIANT_MASK_DBG_CORRELATE) != 0ULL;
+}
diff --git a/compiler-rt/lib/profile/InstrProfiling.h b/compiler-rt/lib/profile/InstrProfiling.h
index e143149fca82707..b8104af5f12b910 100644
--- a/compiler-rt/lib/profile/InstrProfiling.h
+++ b/compiler-rt/lib/profile/InstrProfiling.h
@@ -261,6 +261,9 @@ uint64_t __llvm_profile_get_magic(void);
/*! \brief Get the version of the file format. */
uint64_t __llvm_profile_get_version(void);
+/*! \brief If the binary is compiled with profile correlation. */
+int hasCorrelation();
+
/*! \brief Get the number of entries in the profile data section. */
uint64_t __llvm_profile_get_num_data(const __llvm_profile_data *Begin,
const __llvm_profile_data *End);
@@ -282,6 +285,9 @@ uint64_t __llvm_profile_get_counters_size(const char *Begin, const char *End);
uint64_t __llvm_profile_get_num_bitmap_bytes(const char *Begin,
const char *End);
+/*! \brief Get the size of the profile name section in bytes. */
+uint64_t __llvm_profile_get_name_size(const char *Begin, const char *End);
+
/* ! \brief Given the sizes of the data and counter information, return the
* number of padding bytes before and after the counters, and after the names,
* in the raw profile.
diff --git a/compiler-rt/lib/profile/InstrProfilingBuffer.c b/compiler-rt/lib/profile/InstrProfilingBuffer.c
index c7217b2dfef8a97..69965142d978746 100644
--- a/compiler-rt/lib/profile/InstrProfilingBuffer.c
+++ b/compiler-rt/lib/profile/InstrProfilingBuffer.c
@@ -56,6 +56,8 @@ uint64_t __llvm_profile_get_size_for_buffer(void) {
COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_num_data(const __llvm_profile_data *Begin,
const __llvm_profile_data *End) {
+ if (hasCorrelation())
+ return 0;
intptr_t BeginI = (intptr_t)Begin, EndI = (intptr_t)End;
return ((EndI + sizeof(__llvm_profile_data) - 1) - BeginI) /
sizeof(__llvm_profile_data);
@@ -64,6 +66,8 @@ uint64_t __llvm_profile_get_num_data(const __llvm_profile_data *Begin,
COMPILER_RT_VISIBILITY
uint64_t __llvm_profile_get_data_size(const __llvm_profile_data *Begin,
const __llvm_profile_data *End) {
+ if (hasCorrelation())
+ return 0;
return __llvm_profile_get_num_data(Begin, End) * sizeof(__llvm_profile_data);
}
@@ -92,6 +96,13 @@ uint64_t __llvm_profile_get_num_bitmap_bytes(const char *Begin,
return (End - Begin);
}
+COMPILER_RT_VISIBILITY
+uint64_t __llvm_profile_get_name_size(const char *Begin, const char *End) {
+ if (hasCorrelation())
+ return 0;
+ return End - Begin;
+}
+
/// Calculate the number of padding bytes needed to add to \p Offset in order
/// for (\p Offset + Padding) to be page-aligned.
static uint64_t calculateBytesNeededToPageAlign(uint64_t Offset) {
diff --git a/compiler-rt/lib/profile/InstrProfilingMerge.c b/compiler-rt/lib/profile/InstrProfilingMerge.c
index c5f168bf7517718..b08973debda94f3 100644
--- a/compiler-rt/lib/profile/InstrProfilingMerge.c
+++ b/compiler-rt/lib/profile/InstrProfilingMerge.c
@@ -69,8 +69,9 @@ int __llvm_profile_check_compatibility(const char *ProfileData,
Header->NumBitmapBytes !=
__llvm_profile_get_num_bitmap_bytes(__llvm_profile_begin_bitmap(),
__llvm_profile_end_bitmap()) ||
- Header->NamesSize != (uint64_t)(__llvm_profile_end_names() -
- __llvm_profile_begin_names()) ||
+ Header->NamesSize !=
+ __llvm_profile_get_name_size(__llvm_profile_begin_names(),
+ __llvm_profile_end_names()) ||
Header->ValueKindLast != IPVK_Last)
return 1;
@@ -138,9 +139,9 @@ int __llvm_profile_merge_from_buffer(const char *ProfileData,
if (SrcNameStart < SrcCountersStart || SrcNameStart < SrcBitmapStart)
return 1;
- // Merge counters by iterating the entire counter section when debug info
- // correlation is enabled.
- if (__llvm_profile_get_version() & VARIANT_MASK_DBG_CORRELATE) {
+ // Merge counters by iterating the entire counter section when correlation is
+ // enabled.
+ if (hasCorrelation()) {
for (SrcCounter = SrcCountersStart,
DstCounter = __llvm_profile_begin_counters();
SrcCounter < SrcCountersEnd;) {
diff --git a/compiler-rt/lib/profile/InstrProfilingWriter.c b/compiler-rt/lib/profile/InstrProfilingWriter.c
index 3b61f3def9f6ef0..d35ee6b20504f3e 100644
--- a/compiler-rt/lib/profile/InstrProfilingWriter.c
+++ b/compiler-rt/lib/profile/InstrProfilingWriter.c
@@ -262,21 +262,19 @@ lprofWriteDataImpl(ProfDataWriter *Writer, const __llvm_profile_data *DataBegin,
const char *BitmapBegin, const char *BitmapEnd,
VPDataReaderType *VPDataReader, const char *NamesBegin,
const char *NamesEnd, int SkipNameDataWrite) {
- int DebugInfoCorrelate =
- (__llvm_profile_get_version() & VARIANT_MASK_DBG_CORRELATE) != 0ULL;
+ int ProfileCorrelation = hasCorrelation();
/* Calculate size of sections. */
const uint64_t DataSectionSize =
- DebugInfoCorrelate ? 0 : __llvm_profile_get_data_size(DataBegin, DataEnd);
- const uint64_t NumData =
- DebugInfoCorrelate ? 0 : __llvm_profile_get_num_data(DataBegin, DataEnd);
+ __llvm_profile_get_data_size(DataBegin, DataEnd);
+ const uint64_t NumData = __llvm_profile_get_num_data(DataBegin, DataEnd);
const uint64_t CountersSectionSize =
__llvm_profile_get_counters_size(CountersBegin, CountersEnd);
const uint64_t NumCounters =
__llvm_profile_get_num_counters(CountersBegin, CountersEnd);
const uint64_t NumBitmapBytes =
__llvm_profile_get_num_bitmap_bytes(BitmapBegin, BitmapEnd);
- const uint64_t NamesSize = DebugInfoCorrelate ? 0 : NamesEnd - NamesBegin;
+ const uint64_t NamesSize = __llvm_profile_get_name_size(NamesBegin, NamesEnd);
/* Create the header. */
__llvm_profile_header Header;
@@ -304,7 +302,7 @@ lprofWriteDataImpl(ProfDataWriter *Writer, const __llvm_profile_data *DataBegin,
#endif
/* The data and names sections are omitted in lightweight mode. */
- if (DebugInfoCorrelate) {
+ if (ProfileCorrelation) {
Header.CountersDelta = 0;
Header.NamesDelta = 0;
}
@@ -320,21 +318,22 @@ lprofWriteDataImpl(ProfDataWriter *Writer, const __llvm_profile_data *DataBegin,
/* Write the profile data. */
ProfDataIOVec IOVecData[] = {
- {DebugInfoCorrelate ? NULL : DataBegin, sizeof(uint8_t), DataSectionSize,
+ {ProfileCorrelation ? NULL : DataBegin, sizeof(uint8_t), DataSectionSize,
0},
{NULL, sizeof(uint8_t), PaddingBytesBeforeCounters, 1},
{CountersBegin, sizeof(uint8_t), CountersSectionSize, 0},
{NULL, sizeof(uint8_t), PaddingBytesAfterCounters, 1},
{BitmapBegin, sizeof(uint8_t), NumBitmapBytes, 0},
{NULL, sizeof(uint8_t), PaddingBytesAfterBitmapBytes, 1},
- {(SkipNameDataWrite || DebugInfoCorrelate) ? NULL : NamesBegin,
+ {(SkipNameDataWrite || ProfileCorrelation) ? NULL : NamesBegin,
sizeof(uint8_t), NamesSize, 0},
{NULL, sizeof(uint8_t), PaddingBytesAfterNames, 1}};
if (Writer->Write(Writer, IOVecData, sizeof(IOVecData) / sizeof(*IOVecData)))
return -1;
- /* Value profiling is not yet supported in continuous mode. */
- if (__llvm_profile_is_continuous_mode_enabled())
+ /* Value profiling is not yet supported in continuous mode and profile
+ * correlation mode. */
+ if (__llvm_profile_is_continuous_mode_enabled() || ProfileCorrelation)
return 0;
return writeValueProfData(Writer, VPDataReader, DataBegin, DataEnd);
diff --git a/compiler-rt/test/profile/Linux/instrprof-show-debug-info-correlation.c b/compiler-rt/test/profile/Linux/instrprof-show-debug-info-correlation.c
index 226d678aca347a4..245dc798910425b 100644
--- a/compiler-rt/test/profile/Linux/instrprof-show-debug-info-correlation.c
+++ b/compiler-rt/test/profile/Linux/instrprof-show-debug-info-correlation.c
@@ -4,7 +4,7 @@
// RUN: %clang_pgogen -o %t.no.dbg -mllvm --debug-info-correlate -mllvm --disable-vp=true %s
// RUN: not llvm-profdata show --debug-info=%t.no.dbg 2>&1 | FileCheck %s --check-prefix NO-DBG
-// NO-DBG: unable to correlate profile: could not find any profile metadata in debug info
+// NO-DBG: unable to correlate profile: could not find any profile data metadata in correlated file
// YAML: Probes:
// YAML: - Function Name: a
diff --git a/llvm/include/llvm/ProfileData/InstrProfCorrelator.h b/llvm/include/llvm/ProfileData/InstrProfCorrelator.h
index dd062951f277c1c..a3a0805a294a20c 100644
--- a/llvm/include/llvm/ProfileData/InstrProfCorrelator.h
+++ b/llvm/include/llvm/ProfileData/InstrProfCorrelator.h
@@ -31,8 +31,11 @@ class ObjectFile;
/// to their functions.
class InstrProfCorrelator {
public:
+ /// Indicate which kind correlator to use.
+ enum ProfCorrelatorKind { NONE, DEBUG_INFO };
+
static llvm::Expected<std::unique_ptr<InstrProfCorrelator>>
- get(StringRef DebugInfoFilename);
+ get(StringRef Filename, ProfCorrelatorKind FileKind);
/// Construct a ProfileData vector used to correlate raw instrumentation data
/// to their functions.
@@ -104,7 +107,7 @@ class InstrProfCorrelator {
private:
static llvm::Expected<std::unique_ptr<InstrProfCorrelator>>
- get(std::unique_ptr<MemoryBuffer> Buffer);
+ get(std::unique_ptr<MemoryBuffer> Buffer, ProfCorrelatorKind FileKind);
const InstrProfCorrelatorKind Kind;
};
@@ -128,7 +131,7 @@ class InstrProfCorrelatorImpl : public InstrProfCorrelator {
static llvm::Expected<std::unique_ptr<InstrProfCorrelatorImpl<IntPtrT>>>
get(std::unique_ptr<InstrProfCorrelator::Context> Ctx,
- const object::ObjectFile &Obj);
+ const object::ObjectFile &Obj, ProfCorrelatorKind FileKind);
protected:
std::vector<RawInstrProf::ProfileData<IntPtrT>> Data;
@@ -138,6 +141,8 @@ class InstrProfCorrelatorImpl : public InstrProfCorrelator {
int MaxWarnings,
InstrProfCorrelator::CorrelationData *Data = nullptr) = 0;
+ virtual Error correlateProfileNameImpl() = 0;
+
Error dumpYaml(int MaxWarnings, raw_ostream &OS) override;
void addProbe(StringRef FunctionName, uint64_t CFGHash, IntPtrT CounterOffset,
@@ -205,6 +210,8 @@ class DwarfInstrProfCorrelator : public InstrProfCorrelatorImpl<IntPtrT> {
void correlateProfileDataImpl(
int MaxWarnings,
InstrProfCorrelator::CorrelationData *Data = nullptr) override;
+
+ Error correlateProfileNameImpl() override;
};
} // end namespace llvm
diff --git a/llvm/include/llvm/ProfileData/InstrProfReader.h b/llvm/include/llvm/ProfileData/InstrProfReader.h
index cf6429a324d36b3..1084a58eb098d12 100644
--- a/llvm/include/llvm/ProfileData/InstrProfReader.h
+++ b/llvm/include/llvm/ProfileData/InstrProfReader.h
@@ -377,6 +377,8 @@ class RawInstrProfReader : public InstrProfReader {
return (Version & VARIANT_MASK_DBG_CORRELATE) != 0;
}
+ bool useCorrelate() const { return useDebugInfoCorrelate(); }
+
bool hasSingleByteCoverage() const override {
return (Version & VARIANT_MASK_BYTE_COVERAGE) != 0;
}
diff --git a/llvm/lib/ProfileData/InstrProfCorrelator.cpp b/llvm/lib/ProfileData/InstrProfCorrelator.cpp
index 2138368500bed09..e429b9f1da54cba 100644
--- a/llvm/lib/ProfileData/InstrProfCorrelator.cpp
+++ b/llvm/lib/ProfileData/InstrProfCorrelator.cpp
@@ -24,15 +24,20 @@
using namespace llvm;
-/// Get the __llvm_prf_cnts section.
-Expected<object::SectionRef> getCountersSection(const object::ObjectFile &Obj) {
+/// Get profile section.
+Expected<object::SectionRef> getInstrProfSection(const object::ObjectFile &Obj,
+ InstrProfSectKind IPSK) {
+ Triple::ObjectFormatType ObjFormat = Obj.getTripleObjectFormat();
+ std::string ExpectedSectionName =
+ getInstrProfSectionName(IPSK, ObjFormat,
+ /*AddSegmentInfo=*/false);
for (auto &Section : Obj.sections())
if (auto SectionName = Section.getName())
- if (SectionName.get() == INSTR_PROF_CNTS_SECT_NAME)
+ if (SectionName.get() == ExpectedSectionName)
return Section;
return make_error<InstrProfError>(
instrprof_error::unable_to_correlate_profile,
- "could not find counter section (" INSTR_PROF_CNTS_SECT_NAME ")");
+ "could not find section (" + Twine(ExpectedSectionName) + ")");
}
const char *InstrProfCorrelator::FunctionNameAttributeName = "Function Name";
@@ -42,7 +47,7 @@ const char *InstrProfCorrelator::NumCountersAttributeName = "Num Counters";
llvm::Expected<std::unique_ptr<InstrProfCorrelator::Context>>
InstrProfCorrelator::Context::get(std::unique_ptr<MemoryBuffer> Buffer,
const object::ObjectFile &Obj) {
- auto CountersSection = getCountersSection(Obj);
+ auto CountersSection = getInstrProfSection(Obj, IPSK_cnts);
if (auto Err = CountersSection.takeError())
return std::move(Err);
auto C = std::make_unique<Context>();
@@ -54,30 +59,32 @@ InstrProfCorrelator::Context::get(std::unique_ptr<MemoryBuffer> Buffer,
}
llvm::Expected<std::unique_ptr<InstrProfCorrelator>>
-InstrProfCorrelator::get(StringRef DebugInfoFilename) {
- auto DsymObjectsOrErr =
- object::MachOObjectFile::findDsymObjectMembers(DebugInfoFilename);
- if (auto Err = DsymObjectsOrErr.takeError())
- return std::move(Err);
- if (!DsymObjectsOrErr->empty()) {
- // TODO: Enable profile correlation when there are multiple objects in a
- // dSYM bundle.
- if (DsymObjectsOrErr->size() > 1)
- return make_error<InstrProfError>(
- instrprof_error::unable_to_correlate_profile,
- "using multiple objects is not yet supported");
- DebugInfoFilename = *DsymObjectsOrErr->begin();
+InstrProfCorrelator::get(StringRef Filename, ProfCorrelatorKind FileKind) {
+ if (FileKind == DEBUG_INFO) {
+ auto DsymObjectsOrErr =
+ object::MachOObjectFile::findDsymObjectMembers(Filename);
+ if (auto Err = DsymObjectsOrErr.takeError())
+ return std::move(Err);
+ if (!DsymObjectsOrErr->empty()) {
+ // TODO: Enable profile correlation when there are multiple objects in a
+ // dSYM bundle.
+ if (DsymObjectsOrErr->size() > 1)
+ return make_error<InstrProfError>(
+ instrprof_error::unable_to_correlate_profile,
+ "using multiple objects is not yet supported");
+ Filename = *DsymObjectsOrErr->begin();
+ }
}
- auto BufferOrErr =
- errorOrToExpected(MemoryBuffer::getFile(DebugInfoFilename));
+ auto BufferOrErr = errorOrToExpected(MemoryBuffer::getFile(Filename));
if (auto Err = BufferOrErr.takeError())
return std::move(Err);
- return get(std::move(*BufferOrErr));
+ return get(std::move(*BufferOrErr), FileKind);
}
llvm::Expected<std::unique_ptr<InstrProfCorrelator>>
-InstrProfCorrelator::get(std::unique_ptr<MemoryBuffer> Buffer) {
+InstrProfCorrelator::get(std::unique_ptr<MemoryBuffer> Buffer,
+ ProfCorrelatorKind FileKind) {
auto BinOrErr = object::createBinary(*Buffer);
if (auto Err = BinOrErr.takeError())
return std::move(Err);
@@ -88,9 +95,11 @@ InstrProfCorrelator::get(std::unique_ptr<MemoryBuffer> Buffer) {
return std::move(Err);
auto T = Obj->makeTriple();
if (T.isArch64Bit())
- return InstrProfCorrelatorImpl<uint64_t>::get(std::move(*CtxOrErr), *Obj);
+ return InstrProfCorrelatorImpl<uint64_t>::get(std::move(*CtxOrErr), *Obj,
+ FileKind);
if (T.isArch32Bit())
- return InstrProfCorrelatorImpl<uint32_t>::get(std::move(*CtxOrErr), *Obj);
+ return InstrProfCorrelatorImpl<uint32_t>::get(std::move(*CtxOrErr), *Obj,
+ FileKind);
}
return make_error<InstrProfError>(
instrprof_error::unable_to_correlate_profile, "not an object file");
@@ -132,29 +141,33 @@ template <class IntPtrT>
llvm::Expected<std::unique_ptr<InstrProfCorrelatorImpl<IntPtrT>>>
InstrProfCorrelatorImpl<IntPtrT>::get(
std::unique_ptr<InstrProfCorrelator::Context> Ctx,
- const object::ObjectFile &Obj) {
- if (Obj.isELF() || Obj.isMachO()) {
- auto DICtx = DWARFContext::create(Obj);
- return std::make_unique<DwarfInstrProfCorrelator<IntPtrT>>(std::move(DICtx),
- std::move(Ctx));
+ const object::ObjectFile &Obj, ProfCorrelatorKind FileKind) {
+ if (FileKind == DEBUG_INFO) {
+ if (Obj.isELF() || Obj.isMachO()) {
+ auto DICtx = DWARFContext::create(Obj);
+ return std::make_unique<DwarfInstrProfCorrelator<IntPtrT>>(
+ std::move(DICtx), std::move(Ctx));
+ }
+ return make_error<InstrProfError>(
+ instrprof_error::unable_to_correlate_profile,
+ "unsupported debug info format (only DWARF is supported)");
}
return make_error<InstrProfError>(
instrprof_error::unable_to_correlate_profile,
- "unsupported debug info format (only DWARF is supported)");
+ "unsupported correlation file type (only DWARF is supported)");
}
template <class IntPtrT>
Error InstrProfCorrelatorImpl<IntPtrT>::correlateProfileData(int MaxWarnings) {
assert(Data.empty() && Names.empty() && NamesVec.empty());
correlateProfileDataImpl(MaxWarnings);
- if (Data.empty() || NamesVec.empty())
+ if (this->Data.empty())
return make_error<InstrProfError>(
instrprof_error::unable_to_correlate_profile,
- "could not find any profile metadata in debug info");
- auto Result =
- collectGlobalObjectNameStrings(NamesVec, /*doCompression=*/false, Names);
- CounterOffsets.clear();
- NamesVec.clear();
+ "could not find any profile data metadata in correlated file");
+ Error Result = correlateProfileNameImpl();
+ this->CounterOffsets.clear();
+ this->NamesVec.clear();
return Result;
}
@@ -189,7 +202,7 @@ Error InstrProfCorrelatorImpl<IntPtrT>::dumpYaml(int MaxWarnings,
if (Data.Probes.empty())
return make_error<InstrProfError>(
instrprof_error::unable_to_correlate_profile,
- "could not find any profile metadata in debug info");
+ "could not find any profile data metadata in debug info");
yaml::Output YamlOS(OS);
YamlOS << Data;
return Error::success();
@@ -365,3 +378,16 @@ void DwarfInstrProfCorrelator<IntPtrT>::correlateProfileDataImpl(
WithColor::warning() << format("Suppressed %d additional warnings\n",
NumSuppressedWarnings);
}
+
+template <class IntPtrT>
+Error DwarfInstrProfCorrelator<IntPtrT>::correlateProfileNameImpl() {
+ if (this->NamesVec.empty()) {
+ return make_error<InstrProfError>(
+ instrprof_error::unable_to_correlate_profile,
+ "could not find any profile name metadata in debug info");
+ }
+ auto Result =
+ collectGlobalObjectNameStrings(this->NamesVec,
+ /*doCompression=*/false, this->Names);
+ return Result;
+}
diff --git a/llvm/lib/ProfileData/InstrProfReader.cpp b/llvm/lib/ProfileData/InstrProfReader.cpp
index 31d3ff2bcbf6ca7..dd66f4247ec73ea 100644
--- a/llvm/lib/ProfileData/InstrProfReader.cpp
+++ b/llvm/lib/ProfileData/InstrProfReader.cpp
@@ -563,9 +563,9 @@ Error RawInstrProfReader<IntPtrT>::readHeader(
"\nPLEASE update this tool to version in the raw profile, or "
"regenerate raw profile with expected version.")
.str());
- if (useDebugInfoCorrelate() && !Correlator)
+ if (useCorrelate() && !Correlator)
return error(instrprof_error::missing_debug_info_for_correlation);
- if (!useDebugInfoCorrelate() && Correlator)
+ if (!useCorrelate() && Correlator)
return error(instrprof_error::unexpected_debug_info_for_correlation);
BinaryIdsSize = swap(Header.BinaryIdsSize);
diff --git a/llvm/tools/llvm-profdata/llvm-profdata.cpp b/llvm/tools/llvm-profda...
[truncated]
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Sorry for so many noise regarding this change. |
I haven't found a way to share information (whether of not binary correlation is enabled) between CodeGen(TargetLoweringObjectFileImpl.cpp) and Instrumentation(InstrProfiling.cpp) components. The explanation is |
|
@ZequanWu this seems to cause issues on macOS: https://green.lab.llvm.org/green/job/clang-stage1-RA/36184/console are failing, could you please take a look or revert? |
It should be fixed by 56e205a. |
Thank you! |
Oh, actually, we can have -profile-correlate flag just need to define it at InstrProfCorrelator.cpp (ProfileData component), which is less desired but working as discussed at #69656 (comment). |
|
I'm a bit concerned about the use of What I think would be a better design is to just omit the respective sections altogether when |
I understand your concern. I think that's the limitation of these modes. You need to either compile all code with
I don't understand how this solves the problem you described above. Can you elaborate a bit more? We still need to decide if we need to omit data and names sections at runtime right? |
If you omit the data and names sections from the object files, then This approach would require slightly more complex logic in the correlator. Currently, we either read the data and names from the profile or from DWARF (depending on the flag), there's no in-between state. With the approach I'm proposing, we would need to combine data from different sources: read the data and names in the profile and combine them with the data and names in the DWARF and/or the unstripped file. |
From my experiments on linux, I found that for debug info correlation But for binary correlation, even though |
|
I am nervous with new If you use the same name for a non-SHF_ALLOC section and a SHF_ALLOC section, the linked output has the SHF_ALLOC flag and you cannot tell what components were non-SHF_ALLOC. Usually, the better idea is to use different section names. It may require some trial and error to see how much complexity this scheme will bring.
It isn't. This is "undefined behavior, no diagnostic required". For The program is ill-formed when I noticed that GNU ld defines |
As discussed in llvm#70856 (comment) and llvm#70856 (comment), it's better not to do runtime check for VARIANT_MASK_DBG_CORRELATE bit in __llvm_profile_raw_version when deciding if profile data/name sections should be dropped or not.
|
Chatted with @MaskRay offline, we come to an agreement that it's not good to use relying on the bit in __llvm_profile_raw_version to decide whether or not to dump data/name sections at runtime for the reasons mentioned above. Sent a PR: #71996
I take back this word. When we do |
As discussed in #70856 (comment) and #70856 (comment), it's better not to do runtime check for VARIANT_MASK_DBG_CORRELATE bit in __llvm_profile_raw_version when deciding if profile data/name sections should be dropped or not.
As discussed in llvm#70856 (comment) and llvm#70856 (comment), it's better not to do runtime check for VARIANT_MASK_DBG_CORRELATE bit in __llvm_profile_raw_version when deciding if profile data/name sections should be dropped or not.
Refactor some code from #69493.
#70712 was reverted due to linking failures. So, I removed
-profile-correlate=flag and kept-debug-info-correlatein this change.