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-rw-r--r--tools/llvm-dwarfdump/Statistics.cpp263
1 files changed, 232 insertions, 31 deletions
diff --git a/tools/llvm-dwarfdump/Statistics.cpp b/tools/llvm-dwarfdump/Statistics.cpp
index f26369b935cb..c29ad783a9e6 100644
--- a/tools/llvm-dwarfdump/Statistics.cpp
+++ b/tools/llvm-dwarfdump/Statistics.cpp
@@ -5,11 +5,18 @@
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/JSON.h"
#define DEBUG_TYPE "dwarfdump"
using namespace llvm;
using namespace object;
+/// This represents the number of categories of debug location coverage being
+/// calculated. The first category is the number of variables with 0% location
+/// coverage, but the last category is the number of variables with 100%
+/// location coverage.
+constexpr int NumOfCoverageCategories = 12;
+
/// Holds statistics for one function (or other entity that has a PC range and
/// contains variables, such as a compile unit).
struct PerFunctionStats {
@@ -43,9 +50,9 @@ struct PerFunctionStats {
unsigned NumVars = 0;
/// Number of variables with source location.
unsigned NumVarSourceLocations = 0;
- /// Number of variables wtih type.
+ /// Number of variables with type.
unsigned NumVarTypes = 0;
- /// Number of variables wtih DW_AT_location.
+ /// Number of variables with DW_AT_location.
unsigned NumVarLocations = 0;
};
@@ -56,16 +63,74 @@ struct GlobalStats {
/// Total number of PC range bytes in each variable's enclosing scope,
/// starting from the first definition of the variable.
unsigned ScopeBytesFromFirstDefinition = 0;
- /// Total number of call site entries (DW_TAG_call_site) or
- /// (DW_AT_call_file & DW_AT_call_line).
+ /// Total number of PC range bytes covered by DW_AT_locations with
+ /// the debug entry values (DW_OP_entry_value).
+ unsigned ScopeEntryValueBytesCovered = 0;
+ /// Total number of PC range bytes covered by DW_AT_locations of
+ /// formal parameters.
+ unsigned ParamScopeBytesCovered = 0;
+ /// Total number of PC range bytes in each variable's enclosing scope,
+ /// starting from the first definition of the variable (only for parameters).
+ unsigned ParamScopeBytesFromFirstDefinition = 0;
+ /// Total number of PC range bytes covered by DW_AT_locations with
+ /// the debug entry values (DW_OP_entry_value) (only for parameters).
+ unsigned ParamScopeEntryValueBytesCovered = 0;
+ /// Total number of PC range bytes covered by DW_AT_locations (only for local
+ /// variables).
+ unsigned VarScopeBytesCovered = 0;
+ /// Total number of PC range bytes in each variable's enclosing scope,
+ /// starting from the first definition of the variable (only for local
+ /// variables).
+ unsigned VarScopeBytesFromFirstDefinition = 0;
+ /// Total number of PC range bytes covered by DW_AT_locations with
+ /// the debug entry values (DW_OP_entry_value) (only for local variables).
+ unsigned VarScopeEntryValueBytesCovered = 0;
+ /// Total number of call site entries (DW_AT_call_file & DW_AT_call_line).
unsigned CallSiteEntries = 0;
+ /// Total number of call site DIEs (DW_TAG_call_site).
+ unsigned CallSiteDIEs = 0;
+ /// Total number of call site parameter DIEs (DW_TAG_call_site_parameter).
+ unsigned CallSiteParamDIEs = 0;
/// Total byte size of concrete functions. This byte size includes
/// inline functions contained in the concrete functions.
- uint64_t FunctionSize = 0;
+ unsigned FunctionSize = 0;
/// Total byte size of inlined functions. This is the total number of bytes
/// for the top inline functions within concrete functions. This can help
/// tune the inline settings when compiling to match user expectations.
- uint64_t InlineFunctionSize = 0;
+ unsigned InlineFunctionSize = 0;
+};
+
+/// Holds accumulated debug location statistics about local variables and
+/// formal parameters.
+struct LocationStats {
+ /// Map the scope coverage decile to the number of variables in the decile.
+ /// The first element of the array (at the index zero) represents the number
+ /// of variables with the no debug location at all, but the last element
+ /// in the vector represents the number of fully covered variables within
+ /// its scope.
+ std::vector<unsigned> VarParamLocStats{
+ std::vector<unsigned>(NumOfCoverageCategories, 0)};
+ /// Map non debug entry values coverage.
+ std::vector<unsigned> VarParamNonEntryValLocStats{
+ std::vector<unsigned>(NumOfCoverageCategories, 0)};
+ /// The debug location statistics for formal parameters.
+ std::vector<unsigned> ParamLocStats{
+ std::vector<unsigned>(NumOfCoverageCategories, 0)};
+ /// Map non debug entry values coverage for formal parameters.
+ std::vector<unsigned> ParamNonEntryValLocStats{
+ std::vector<unsigned>(NumOfCoverageCategories, 0)};
+ /// The debug location statistics for local variables.
+ std::vector<unsigned> VarLocStats{
+ std::vector<unsigned>(NumOfCoverageCategories, 0)};
+ /// Map non debug entry values coverage for local variables.
+ std::vector<unsigned> VarNonEntryValLocStats{
+ std::vector<unsigned>(NumOfCoverageCategories, 0)};
+ /// Total number of local variables and function parameters processed.
+ unsigned NumVarParam = 0;
+ /// Total number of formal parameters processed.
+ unsigned NumParam = 0;
+ /// Total number of local variables processed.
+ unsigned NumVar = 0;
};
/// Extract the low pc from a Die.
@@ -81,27 +146,66 @@ static uint64_t getLowPC(DWARFDie Die) {
return dwarf::toAddress(Die.find(dwarf::DW_AT_low_pc), 0);
}
+/// Collect debug location statistics for one DIE.
+static void collectLocStats(uint64_t BytesCovered, uint64_t BytesInScope,
+ std::vector<unsigned> &VarParamLocStats,
+ std::vector<unsigned> &ParamLocStats,
+ std::vector<unsigned> &VarLocStats, bool IsParam,
+ bool IsLocalVar) {
+ auto getCoverageBucket = [BytesCovered, BytesInScope]() -> unsigned {
+ unsigned LocBucket = 100 * (double)BytesCovered / BytesInScope;
+ if (LocBucket == 0) {
+ // No debug location at all for the variable.
+ return 0;
+ } else if (LocBucket == 100 || BytesCovered > BytesInScope) {
+ // Fully covered variable within its scope.
+ return NumOfCoverageCategories - 1;
+ } else {
+ // Get covered range (e.g. 20%-29%).
+ LocBucket /= 10;
+ return LocBucket + 1;
+ }
+ };
+
+ unsigned CoverageBucket = getCoverageBucket();
+ VarParamLocStats[CoverageBucket]++;
+ if (IsParam)
+ ParamLocStats[CoverageBucket]++;
+ else if (IsLocalVar)
+ VarLocStats[CoverageBucket]++;
+}
+
/// Collect debug info quality metrics for one DIE.
-static void collectStatsForDie(DWARFDie Die, std::string FnPrefix,
+static void collectStatsForDie(DWARFDie Die, uint64_t UnitLowPC, std::string FnPrefix,
std::string VarPrefix, uint64_t ScopeLowPC,
uint64_t BytesInScope, uint32_t InlineDepth,
StringMap<PerFunctionStats> &FnStatMap,
- GlobalStats &GlobalStats) {
+ GlobalStats &GlobalStats,
+ LocationStats &LocStats) {
bool HasLoc = false;
bool HasSrcLoc = false;
bool HasType = false;
bool IsArtificial = false;
uint64_t BytesCovered = 0;
+ uint64_t BytesEntryValuesCovered = 0;
uint64_t OffsetToFirstDefinition = 0;
+ auto &FnStats = FnStatMap[FnPrefix];
+ bool IsParam = Die.getTag() == dwarf::DW_TAG_formal_parameter;
+ bool IsLocalVar = Die.getTag() == dwarf::DW_TAG_variable;
+
+ if (Die.getTag() == dwarf::DW_TAG_call_site ||
+ Die.getTag() == dwarf::DW_TAG_GNU_call_site) {
+ GlobalStats.CallSiteDIEs++;
+ return;
+ }
- if (Die.getTag() == dwarf::DW_TAG_call_site) {
- GlobalStats.CallSiteEntries++;
+ if (Die.getTag() == dwarf::DW_TAG_call_site_parameter ||
+ Die.getTag() == dwarf::DW_TAG_GNU_call_site_parameter) {
+ GlobalStats.CallSiteParamDIEs++;
return;
}
- if (Die.getTag() != dwarf::DW_TAG_formal_parameter &&
- Die.getTag() != dwarf::DW_TAG_variable &&
- Die.getTag() != dwarf::DW_TAG_member) {
+ if (!IsParam && !IsLocalVar && Die.getTag() != dwarf::DW_TAG_member) {
// Not a variable or constant member.
return;
}
@@ -116,6 +220,19 @@ static void collectStatsForDie(DWARFDie Die, std::string FnPrefix,
if (Die.find(dwarf::DW_AT_artificial))
IsArtificial = true;
+ auto IsEntryValue = [&](ArrayRef<uint8_t> D) -> bool {
+ DWARFUnit *U = Die.getDwarfUnit();
+ DataExtractor Data(toStringRef(D),
+ Die.getDwarfUnit()->getContext().isLittleEndian(), 0);
+ DWARFExpression Expression(Data, U->getVersion(), U->getAddressByteSize());
+ // Consider the expression containing the DW_OP_entry_value as
+ // an entry value.
+ return llvm::any_of(Expression, [](DWARFExpression::Operation &Op) {
+ return Op.getCode() == dwarf::DW_OP_entry_value ||
+ Op.getCode() == dwarf::DW_OP_GNU_entry_value;
+ });
+ };
+
if (Die.find(dwarf::DW_AT_const_value)) {
// This catches constant members *and* variables.
HasLoc = true;
@@ -133,11 +250,15 @@ static void collectStatsForDie(DWARFDie Die, std::string FnPrefix,
if (auto DebugLocOffset = FormValue->getAsSectionOffset()) {
auto *DebugLoc = Die.getDwarfUnit()->getContext().getDebugLoc();
if (auto List = DebugLoc->getLocationListAtOffset(*DebugLocOffset)) {
- for (auto Entry : List->Entries)
- BytesCovered += Entry.End - Entry.Begin;
+ for (auto Entry : List->Entries) {
+ uint64_t BytesEntryCovered = Entry.End - Entry.Begin;
+ BytesCovered += BytesEntryCovered;
+ if (IsEntryValue(Entry.Loc))
+ BytesEntryValuesCovered += BytesEntryCovered;
+ }
if (List->Entries.size()) {
uint64_t FirstDef = List->Entries[0].Begin;
- uint64_t UnitOfs = getLowPC(Die.getDwarfUnit()->getUnitDIE());
+ uint64_t UnitOfs = UnitLowPC;
// Ranges sometimes start before the lexical scope.
if (UnitOfs + FirstDef >= ScopeLowPC)
OffsetToFirstDefinition = UnitOfs + FirstDef - ScopeLowPC;
@@ -154,8 +275,25 @@ static void collectStatsForDie(DWARFDie Die, std::string FnPrefix,
}
}
+ // Calculate the debug location statistics.
+ if (BytesInScope) {
+ LocStats.NumVarParam++;
+ if (IsParam)
+ LocStats.NumParam++;
+ else if (IsLocalVar)
+ LocStats.NumVar++;
+
+ collectLocStats(BytesCovered, BytesInScope, LocStats.VarParamLocStats,
+ LocStats.ParamLocStats, LocStats.VarLocStats, IsParam,
+ IsLocalVar);
+ // Non debug entry values coverage statistics.
+ collectLocStats(BytesCovered - BytesEntryValuesCovered, BytesInScope,
+ LocStats.VarParamNonEntryValLocStats,
+ LocStats.ParamNonEntryValLocStats,
+ LocStats.VarNonEntryValLocStats, IsParam, IsLocalVar);
+ }
+
// Collect PC range coverage data.
- auto &FnStats = FnStatMap[FnPrefix];
if (DWARFDie D =
Die.getAttributeValueAsReferencedDie(dwarf::DW_AT_abstract_origin))
Die = D;
@@ -171,6 +309,17 @@ static void collectStatsForDie(DWARFDie Die, std::string FnPrefix,
// Turns out we have a lot of ranges that extend past the lexical scope.
GlobalStats.ScopeBytesCovered += std::min(BytesInScope, BytesCovered);
GlobalStats.ScopeBytesFromFirstDefinition += BytesInScope;
+ GlobalStats.ScopeEntryValueBytesCovered += BytesEntryValuesCovered;
+ if (IsParam) {
+ GlobalStats.ParamScopeBytesCovered +=
+ std::min(BytesInScope, BytesCovered);
+ GlobalStats.ParamScopeBytesFromFirstDefinition += BytesInScope;
+ GlobalStats.ParamScopeEntryValueBytesCovered += BytesEntryValuesCovered;
+ } else if (IsLocalVar) {
+ GlobalStats.VarScopeBytesCovered += std::min(BytesInScope, BytesCovered);
+ GlobalStats.VarScopeBytesFromFirstDefinition += BytesInScope;
+ GlobalStats.VarScopeEntryValueBytesCovered += BytesEntryValuesCovered;
+ }
assert(GlobalStats.ScopeBytesCovered <=
GlobalStats.ScopeBytesFromFirstDefinition);
} else if (Die.getTag() == dwarf::DW_TAG_member) {
@@ -179,7 +328,7 @@ static void collectStatsForDie(DWARFDie Die, std::string FnPrefix,
FnStats.TotalVarWithLoc += (unsigned)HasLoc;
}
if (!IsArtificial) {
- if (Die.getTag() == dwarf::DW_TAG_formal_parameter) {
+ if (IsParam) {
FnStats.NumParams++;
if (HasType)
FnStats.NumParamTypes++;
@@ -187,7 +336,7 @@ static void collectStatsForDie(DWARFDie Die, std::string FnPrefix,
FnStats.NumParamSourceLocations++;
if (HasLoc)
FnStats.NumParamLocations++;
- } else if (Die.getTag() == dwarf::DW_TAG_variable) {
+ } else if (IsLocalVar) {
FnStats.NumVars++;
if (HasType)
FnStats.NumVarTypes++;
@@ -200,11 +349,12 @@ static void collectStatsForDie(DWARFDie Die, std::string FnPrefix,
}
/// Recursively collect debug info quality metrics.
-static void collectStatsRecursive(DWARFDie Die, std::string FnPrefix,
+static void collectStatsRecursive(DWARFDie Die, uint64_t UnitLowPC, std::string FnPrefix,
std::string VarPrefix, uint64_t ScopeLowPC,
uint64_t BytesInScope, uint32_t InlineDepth,
StringMap<PerFunctionStats> &FnStatMap,
- GlobalStats &GlobalStats) {
+ GlobalStats &GlobalStats,
+ LocationStats &LocStats) {
// Handle any kind of lexical scope.
const dwarf::Tag Tag = Die.getTag();
const bool IsFunction = Tag == dwarf::DW_TAG_subprogram;
@@ -272,8 +422,8 @@ static void collectStatsRecursive(DWARFDie Die, std::string FnPrefix,
}
} else {
// Not a scope, visit the Die itself. It could be a variable.
- collectStatsForDie(Die, FnPrefix, VarPrefix, ScopeLowPC, BytesInScope,
- InlineDepth, FnStatMap, GlobalStats);
+ collectStatsForDie(Die, UnitLowPC, FnPrefix, VarPrefix, ScopeLowPC, BytesInScope,
+ InlineDepth, FnStatMap, GlobalStats, LocStats);
}
// Set InlineDepth correctly for child recursion
@@ -290,8 +440,9 @@ static void collectStatsRecursive(DWARFDie Die, std::string FnPrefix,
if (Child.getTag() == dwarf::DW_TAG_lexical_block)
ChildVarPrefix += toHex(LexicalBlockIndex++) + '.';
- collectStatsRecursive(Child, FnPrefix, ChildVarPrefix, ScopeLowPC,
- BytesInScope, InlineDepth, FnStatMap, GlobalStats);
+ collectStatsRecursive(Child, UnitLowPC, FnPrefix, ChildVarPrefix, ScopeLowPC,
+ BytesInScope, InlineDepth, FnStatMap, GlobalStats,
+ LocStats);
Child = Child.getSibling();
}
}
@@ -299,14 +450,33 @@ static void collectStatsRecursive(DWARFDie Die, std::string FnPrefix,
/// Print machine-readable output.
/// The machine-readable format is single-line JSON output.
/// \{
-static void printDatum(raw_ostream &OS, const char *Key, StringRef Value) {
- OS << ",\"" << Key << "\":\"" << Value << '"';
- LLVM_DEBUG(llvm::dbgs() << Key << ": " << Value << '\n');
-}
-static void printDatum(raw_ostream &OS, const char *Key, uint64_t Value) {
+static void printDatum(raw_ostream &OS, const char *Key, json::Value Value) {
OS << ",\"" << Key << "\":" << Value;
LLVM_DEBUG(llvm::dbgs() << Key << ": " << Value << '\n');
}
+static void printLocationStats(raw_ostream &OS,
+ const char *Key,
+ std::vector<unsigned> &LocationStats) {
+ OS << ",\"" << Key << " with 0% of its scope covered\":"
+ << LocationStats[0];
+ LLVM_DEBUG(llvm::dbgs() << Key << " with 0% of its scope covered: "
+ << LocationStats[0] << '\n');
+ OS << ",\"" << Key << " with 1-9% of its scope covered\":"
+ << LocationStats[1];
+ LLVM_DEBUG(llvm::dbgs() << Key << " with 1-9% of its scope covered: "
+ << LocationStats[1] << '\n');
+ for (unsigned i = 2; i < NumOfCoverageCategories - 1; ++i) {
+ OS << ",\"" << Key << " with " << (i - 1) * 10 << "-" << i * 10 - 1
+ << "% of its scope covered\":" << LocationStats[i];
+ LLVM_DEBUG(llvm::dbgs()
+ << Key << " with " << (i - 1) * 10 << "-" << i * 10 - 1
+ << "% of its scope covered: " << LocationStats[i]);
+ }
+ OS << ",\"" << Key << " with 100% of its scope covered\":"
+ << LocationStats[NumOfCoverageCategories - 1];
+ LLVM_DEBUG(llvm::dbgs() << Key << " with 100% of its scope covered: "
+ << LocationStats[NumOfCoverageCategories - 1]);
+}
/// \}
/// Collect debug info quality metrics for an entire DIContext.
@@ -321,10 +491,12 @@ bool collectStatsForObjectFile(ObjectFile &Obj, DWARFContext &DICtx,
Twine Filename, raw_ostream &OS) {
StringRef FormatName = Obj.getFileFormatName();
GlobalStats GlobalStats;
+ LocationStats LocStats;
StringMap<PerFunctionStats> Statistics;
for (const auto &CU : static_cast<DWARFContext *>(&DICtx)->compile_units())
if (DWARFDie CUDie = CU->getNonSkeletonUnitDIE(false))
- collectStatsRecursive(CUDie, "/", "g", 0, 0, 0, Statistics, GlobalStats);
+ collectStatsRecursive(CUDie, getLowPC(CUDie), "/", "g", 0, 0, 0,
+ Statistics, GlobalStats, LocStats);
/// The version number should be increased every time the algorithm is changed
/// (including bug fixes). New metrics may be added without increasing the
@@ -387,9 +559,24 @@ bool collectStatsForObjectFile(ObjectFile &Obj, DWARFContext &DICtx,
printDatum(OS, "source variables", VarParamTotal);
printDatum(OS, "variables with location", VarParamWithLoc);
printDatum(OS, "call site entries", GlobalStats.CallSiteEntries);
+ printDatum(OS, "call site DIEs", GlobalStats.CallSiteDIEs);
+ printDatum(OS, "call site parameter DIEs", GlobalStats.CallSiteParamDIEs);
printDatum(OS, "scope bytes total",
GlobalStats.ScopeBytesFromFirstDefinition);
printDatum(OS, "scope bytes covered", GlobalStats.ScopeBytesCovered);
+ printDatum(OS, "entry value scope bytes covered",
+ GlobalStats.ScopeEntryValueBytesCovered);
+ printDatum(OS, "formal params scope bytes total",
+ GlobalStats.ParamScopeBytesFromFirstDefinition);
+ printDatum(OS, "formal params scope bytes covered",
+ GlobalStats.ParamScopeBytesCovered);
+ printDatum(OS, "formal params entry value scope bytes covered",
+ GlobalStats.ParamScopeEntryValueBytesCovered);
+ printDatum(OS, "vars scope bytes total",
+ GlobalStats.VarScopeBytesFromFirstDefinition);
+ printDatum(OS, "vars scope bytes covered", GlobalStats.VarScopeBytesCovered);
+ printDatum(OS, "vars entry value scope bytes covered",
+ GlobalStats.VarScopeEntryValueBytesCovered);
printDatum(OS, "total function size", GlobalStats.FunctionSize);
printDatum(OS, "total inlined function size", GlobalStats.InlineFunctionSize);
printDatum(OS, "total formal params", ParamTotal);
@@ -400,6 +587,20 @@ bool collectStatsForObjectFile(ObjectFile &Obj, DWARFContext &DICtx,
printDatum(OS, "vars with source location", VarWithSrcLoc);
printDatum(OS, "vars with type", VarWithType);
printDatum(OS, "vars with binary location", VarWithLoc);
+ printDatum(OS, "total variables procesed by location statistics",
+ LocStats.NumVarParam);
+ printLocationStats(OS, "variables", LocStats.VarParamLocStats);
+ printLocationStats(OS, "variables (excluding the debug entry values)",
+ LocStats.VarParamNonEntryValLocStats);
+ printDatum(OS, "total params procesed by location statistics",
+ LocStats.NumParam);
+ printLocationStats(OS, "params", LocStats.ParamLocStats);
+ printLocationStats(OS, "params (excluding the debug entry values)",
+ LocStats.ParamNonEntryValLocStats);
+ printDatum(OS, "total vars procesed by location statistics", LocStats.NumVar);
+ printLocationStats(OS, "vars", LocStats.VarLocStats);
+ printLocationStats(OS, "vars (excluding the debug entry values)",
+ LocStats.VarNonEntryValLocStats);
OS << "}\n";
LLVM_DEBUG(
llvm::dbgs() << "Total Availability: "
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-02 05:02:55 +0000