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ae49fd3922
Exposed by D97396
894 lines
35 KiB
C++
894 lines
35 KiB
C++
//===-- Statistics.cpp - Debug Info quality metrics -----------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "llvm-dwarfdump.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/StringSet.h"
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#include "llvm/DebugInfo/DWARF/DWARFContext.h"
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#include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
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#include "llvm/Object/ObjectFile.h"
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#include "llvm/Support/JSON.h"
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#define DEBUG_TYPE "dwarfdump"
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using namespace llvm;
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using namespace llvm::dwarfdump;
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using namespace llvm::object;
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namespace {
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/// This represents the number of categories of debug location coverage being
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/// calculated. The first category is the number of variables with 0% location
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/// coverage, but the last category is the number of variables with 100%
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/// location coverage.
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constexpr int NumOfCoverageCategories = 12;
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/// This is used for zero location coverage bucket.
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constexpr unsigned ZeroCoverageBucket = 0;
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/// This represents variables DIE offsets.
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using InlinedVarsTy = llvm::SmallVector<uint64_t>;
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/// This maps function DIE offset to its variables.
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using InlinedVarsTyMap = llvm::DenseMap<uint64_t, InlinedVarsTy>;
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/// This represents inlined_subroutine DIE offsets.
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using InlinedFnInstacesTy = llvm::SmallVector<uint64_t>;
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/// Holds statistics for one function (or other entity that has a PC range and
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/// contains variables, such as a compile unit).
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struct PerFunctionStats {
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/// Number of inlined instances of this function.
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unsigned NumFnInlined = 0;
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/// Number of out-of-line instances of this function.
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unsigned NumFnOutOfLine = 0;
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/// Number of inlined instances that have abstract origins.
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unsigned NumAbstractOrigins = 0;
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/// Number of variables and parameters with location across all inlined
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/// instances.
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unsigned TotalVarWithLoc = 0;
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/// Number of constants with location across all inlined instances.
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unsigned ConstantMembers = 0;
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/// Number of arificial variables, parameters or members across all instances.
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unsigned NumArtificial = 0;
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/// List of all Variables and parameters in this function.
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StringSet<> VarsInFunction;
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/// Compile units also cover a PC range, but have this flag set to false.
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bool IsFunction = false;
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/// Function has source location information.
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bool HasSourceLocation = false;
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/// Number of function parameters.
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unsigned NumParams = 0;
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/// Number of function parameters with source location.
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unsigned NumParamSourceLocations = 0;
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/// Number of function parameters with type.
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unsigned NumParamTypes = 0;
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/// Number of function parameters with a DW_AT_location.
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unsigned NumParamLocations = 0;
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/// Number of local variables.
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unsigned NumLocalVars = 0;
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/// Number of local variables with source location.
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unsigned NumLocalVarSourceLocations = 0;
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/// Number of local variables with type.
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unsigned NumLocalVarTypes = 0;
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/// Number of local variables with DW_AT_location.
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unsigned NumLocalVarLocations = 0;
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};
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/// Holds accumulated global statistics about DIEs.
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struct GlobalStats {
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/// Total number of PC range bytes covered by DW_AT_locations.
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unsigned TotalBytesCovered = 0;
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/// Total number of parent DIE PC range bytes covered by DW_AT_Locations.
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unsigned ScopeBytesCovered = 0;
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/// Total number of PC range bytes in each variable's enclosing scope.
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unsigned ScopeBytes = 0;
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/// Total number of PC range bytes covered by DW_AT_locations with
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/// the debug entry values (DW_OP_entry_value).
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unsigned ScopeEntryValueBytesCovered = 0;
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/// Total number of PC range bytes covered by DW_AT_locations of
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/// formal parameters.
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unsigned ParamScopeBytesCovered = 0;
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/// Total number of PC range bytes in each parameter's enclosing scope.
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unsigned ParamScopeBytes = 0;
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/// Total number of PC range bytes covered by DW_AT_locations with
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/// the debug entry values (DW_OP_entry_value) (only for parameters).
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unsigned ParamScopeEntryValueBytesCovered = 0;
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/// Total number of PC range bytes covered by DW_AT_locations (only for local
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/// variables).
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unsigned LocalVarScopeBytesCovered = 0;
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/// Total number of PC range bytes in each local variable's enclosing scope.
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unsigned LocalVarScopeBytes = 0;
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/// Total number of PC range bytes covered by DW_AT_locations with
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/// the debug entry values (DW_OP_entry_value) (only for local variables).
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unsigned LocalVarScopeEntryValueBytesCovered = 0;
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/// Total number of call site entries (DW_AT_call_file & DW_AT_call_line).
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unsigned CallSiteEntries = 0;
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/// Total number of call site DIEs (DW_TAG_call_site).
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unsigned CallSiteDIEs = 0;
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/// Total number of call site parameter DIEs (DW_TAG_call_site_parameter).
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unsigned CallSiteParamDIEs = 0;
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/// Total byte size of concrete functions. This byte size includes
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/// inline functions contained in the concrete functions.
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unsigned FunctionSize = 0;
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/// Total byte size of inlined functions. This is the total number of bytes
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/// for the top inline functions within concrete functions. This can help
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/// tune the inline settings when compiling to match user expectations.
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unsigned InlineFunctionSize = 0;
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};
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/// Holds accumulated debug location statistics about local variables and
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/// formal parameters.
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struct LocationStats {
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/// Map the scope coverage decile to the number of variables in the decile.
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/// The first element of the array (at the index zero) represents the number
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/// of variables with the no debug location at all, but the last element
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/// in the vector represents the number of fully covered variables within
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/// its scope.
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std::vector<unsigned> VarParamLocStats{
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std::vector<unsigned>(NumOfCoverageCategories, 0)};
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/// Map non debug entry values coverage.
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std::vector<unsigned> VarParamNonEntryValLocStats{
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std::vector<unsigned>(NumOfCoverageCategories, 0)};
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/// The debug location statistics for formal parameters.
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std::vector<unsigned> ParamLocStats{
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std::vector<unsigned>(NumOfCoverageCategories, 0)};
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/// Map non debug entry values coverage for formal parameters.
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std::vector<unsigned> ParamNonEntryValLocStats{
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std::vector<unsigned>(NumOfCoverageCategories, 0)};
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/// The debug location statistics for local variables.
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std::vector<unsigned> LocalVarLocStats{
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std::vector<unsigned>(NumOfCoverageCategories, 0)};
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/// Map non debug entry values coverage for local variables.
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std::vector<unsigned> LocalVarNonEntryValLocStats{
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std::vector<unsigned>(NumOfCoverageCategories, 0)};
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/// Total number of local variables and function parameters processed.
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unsigned NumVarParam = 0;
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/// Total number of formal parameters processed.
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unsigned NumParam = 0;
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/// Total number of local variables processed.
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unsigned NumVar = 0;
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};
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} // namespace
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/// Collect debug location statistics for one DIE.
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static void collectLocStats(uint64_t ScopeBytesCovered, uint64_t BytesInScope,
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std::vector<unsigned> &VarParamLocStats,
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std::vector<unsigned> &ParamLocStats,
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std::vector<unsigned> &LocalVarLocStats,
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bool IsParam, bool IsLocalVar) {
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auto getCoverageBucket = [ScopeBytesCovered, BytesInScope]() -> unsigned {
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// No debug location at all for the variable.
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if (ScopeBytesCovered == 0)
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return 0;
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// Fully covered variable within its scope.
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if (ScopeBytesCovered >= BytesInScope)
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return NumOfCoverageCategories - 1;
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// Get covered range (e.g. 20%-29%).
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unsigned LocBucket = 100 * (double)ScopeBytesCovered / BytesInScope;
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LocBucket /= 10;
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return LocBucket + 1;
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};
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unsigned CoverageBucket = getCoverageBucket();
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VarParamLocStats[CoverageBucket]++;
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if (IsParam)
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ParamLocStats[CoverageBucket]++;
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else if (IsLocalVar)
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LocalVarLocStats[CoverageBucket]++;
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}
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/// Construct an identifier for a given DIE from its Prefix, Name, DeclFileName
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/// and DeclLine. The identifier aims to be unique for any unique entities,
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/// but keeping the same among different instances of the same entity.
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static std::string constructDieID(DWARFDie Die,
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StringRef Prefix = StringRef()) {
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std::string IDStr;
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llvm::raw_string_ostream ID(IDStr);
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ID << Prefix
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<< Die.getName(DINameKind::LinkageName);
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// Prefix + Name is enough for local variables and parameters.
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if (!Prefix.empty() && !Prefix.equals("g"))
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return ID.str();
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auto DeclFile = Die.findRecursively(dwarf::DW_AT_decl_file);
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std::string File;
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if (DeclFile) {
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DWARFUnit *U = Die.getDwarfUnit();
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if (const auto *LT = U->getContext().getLineTableForUnit(U))
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if (LT->getFileNameByIndex(
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dwarf::toUnsigned(DeclFile, 0), U->getCompilationDir(),
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DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, File))
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File = std::string(sys::path::filename(File));
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}
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ID << ":" << (File.empty() ? "/" : File);
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ID << ":"
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<< dwarf::toUnsigned(Die.findRecursively(dwarf::DW_AT_decl_line), 0);
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return ID.str();
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}
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/// Return the number of bytes in the overlap of ranges A and B.
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static uint64_t calculateOverlap(DWARFAddressRange A, DWARFAddressRange B) {
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uint64_t Lower = std::max(A.LowPC, B.LowPC);
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uint64_t Upper = std::min(A.HighPC, B.HighPC);
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if (Lower >= Upper)
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return 0;
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return Upper - Lower;
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}
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/// Collect debug info quality metrics for one DIE.
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static void collectStatsForDie(DWARFDie Die, std::string FnPrefix,
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std::string VarPrefix, uint64_t BytesInScope,
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uint32_t InlineDepth,
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StringMap<PerFunctionStats> &FnStatMap,
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GlobalStats &GlobalStats,
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LocationStats &LocStats,
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InlinedVarsTy *InlinedVariables) {
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const dwarf::Tag Tag = Die.getTag();
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// Skip CU node.
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if (Tag == dwarf::DW_TAG_compile_unit)
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return;
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bool HasLoc = false;
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bool HasSrcLoc = false;
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bool HasType = false;
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uint64_t TotalBytesCovered = 0;
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uint64_t ScopeBytesCovered = 0;
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uint64_t BytesEntryValuesCovered = 0;
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auto &FnStats = FnStatMap[FnPrefix];
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bool IsParam = Tag == dwarf::DW_TAG_formal_parameter;
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bool IsLocalVar = Tag == dwarf::DW_TAG_variable;
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bool IsConstantMember = Tag == dwarf::DW_TAG_member &&
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Die.find(dwarf::DW_AT_const_value);
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// For zero covered inlined variables the locstats will be
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// calculated later.
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bool DeferLocStats = false;
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if (Tag == dwarf::DW_TAG_call_site || Tag == dwarf::DW_TAG_GNU_call_site) {
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GlobalStats.CallSiteDIEs++;
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return;
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}
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if (Tag == dwarf::DW_TAG_call_site_parameter ||
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Tag == dwarf::DW_TAG_GNU_call_site_parameter) {
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GlobalStats.CallSiteParamDIEs++;
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return;
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}
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if (!IsParam && !IsLocalVar && !IsConstantMember) {
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// Not a variable or constant member.
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return;
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}
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// Ignore declarations of global variables.
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if (IsLocalVar && Die.find(dwarf::DW_AT_declaration))
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return;
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if (Die.findRecursively(dwarf::DW_AT_decl_file) &&
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Die.findRecursively(dwarf::DW_AT_decl_line))
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HasSrcLoc = true;
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if (Die.findRecursively(dwarf::DW_AT_type))
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HasType = true;
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// Check if it is an inlined variable.
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if (Die.find(dwarf::DW_AT_abstract_origin)) {
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if (Die.find(dwarf::DW_AT_location) ||
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Die.find(dwarf::DW_AT_const_value)) {
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if (InlinedVariables) {
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auto Offset = Die.find(dwarf::DW_AT_abstract_origin);
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// Do not track this inlined var any more, since it has location
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// coverage.
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llvm::erase_value(*InlinedVariables, (*Offset).getRawUValue());
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}
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} else {
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// The locstats will be handled at the end of
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// the collectStatsRecursive().
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DeferLocStats = true;
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}
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}
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auto IsEntryValue = [&](ArrayRef<uint8_t> D) -> bool {
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DWARFUnit *U = Die.getDwarfUnit();
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DataExtractor Data(toStringRef(D),
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Die.getDwarfUnit()->getContext().isLittleEndian(), 0);
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DWARFExpression Expression(Data, U->getAddressByteSize(),
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U->getFormParams().Format);
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// Consider the expression containing the DW_OP_entry_value as
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// an entry value.
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return llvm::any_of(Expression, [](DWARFExpression::Operation &Op) {
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return Op.getCode() == dwarf::DW_OP_entry_value ||
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Op.getCode() == dwarf::DW_OP_GNU_entry_value;
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});
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};
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if (Die.find(dwarf::DW_AT_const_value)) {
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// This catches constant members *and* variables.
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HasLoc = true;
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ScopeBytesCovered = BytesInScope;
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TotalBytesCovered = BytesInScope;
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} else {
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// Handle variables and function arguments.
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Expected<std::vector<DWARFLocationExpression>> Loc =
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Die.getLocations(dwarf::DW_AT_location);
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if (!Loc) {
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consumeError(Loc.takeError());
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} else {
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HasLoc = true;
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// Get PC coverage.
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auto Default = find_if(
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*Loc, [](const DWARFLocationExpression &L) { return !L.Range; });
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if (Default != Loc->end()) {
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// Assume the entire range is covered by a single location.
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ScopeBytesCovered = BytesInScope;
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TotalBytesCovered = BytesInScope;
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} else {
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// Caller checks this Expected result already, it cannot fail.
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auto ScopeRanges = cantFail(Die.getParent().getAddressRanges());
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for (auto Entry : *Loc) {
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TotalBytesCovered += Entry.Range->HighPC - Entry.Range->LowPC;
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uint64_t ScopeBytesCoveredByEntry = 0;
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// Calculate how many bytes of the parent scope this entry covers.
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// FIXME: In section 2.6.2 of the DWARFv5 spec it says that "The
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// address ranges defined by the bounded location descriptions of a
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// location list may overlap". So in theory a variable can have
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// multiple simultaneous locations, which would make this calculation
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// misleading because we will count the overlapped areas
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// twice. However, clang does not currently emit DWARF like this.
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for (DWARFAddressRange R : ScopeRanges) {
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ScopeBytesCoveredByEntry += calculateOverlap(*Entry.Range, R);
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}
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ScopeBytesCovered += ScopeBytesCoveredByEntry;
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if (IsEntryValue(Entry.Expr))
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BytesEntryValuesCovered += ScopeBytesCoveredByEntry;
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}
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}
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}
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}
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// Calculate the debug location statistics.
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if (BytesInScope && !DeferLocStats) {
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LocStats.NumVarParam++;
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if (IsParam)
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LocStats.NumParam++;
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else if (IsLocalVar)
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LocStats.NumVar++;
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collectLocStats(ScopeBytesCovered, BytesInScope, LocStats.VarParamLocStats,
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LocStats.ParamLocStats, LocStats.LocalVarLocStats, IsParam,
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IsLocalVar);
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// Non debug entry values coverage statistics.
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collectLocStats(ScopeBytesCovered - BytesEntryValuesCovered, BytesInScope,
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LocStats.VarParamNonEntryValLocStats,
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LocStats.ParamNonEntryValLocStats,
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LocStats.LocalVarNonEntryValLocStats, IsParam, IsLocalVar);
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}
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// Collect PC range coverage data.
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if (DWARFDie D =
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Die.getAttributeValueAsReferencedDie(dwarf::DW_AT_abstract_origin))
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Die = D;
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std::string VarID = constructDieID(Die, VarPrefix);
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FnStats.VarsInFunction.insert(VarID);
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GlobalStats.TotalBytesCovered += TotalBytesCovered;
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if (BytesInScope) {
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GlobalStats.ScopeBytesCovered += ScopeBytesCovered;
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GlobalStats.ScopeBytes += BytesInScope;
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GlobalStats.ScopeEntryValueBytesCovered += BytesEntryValuesCovered;
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if (IsParam) {
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GlobalStats.ParamScopeBytesCovered += ScopeBytesCovered;
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GlobalStats.ParamScopeBytes += BytesInScope;
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GlobalStats.ParamScopeEntryValueBytesCovered += BytesEntryValuesCovered;
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} else if (IsLocalVar) {
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GlobalStats.LocalVarScopeBytesCovered += ScopeBytesCovered;
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GlobalStats.LocalVarScopeBytes += BytesInScope;
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GlobalStats.LocalVarScopeEntryValueBytesCovered +=
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BytesEntryValuesCovered;
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}
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assert(GlobalStats.ScopeBytesCovered <= GlobalStats.ScopeBytes);
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}
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if (IsConstantMember) {
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FnStats.ConstantMembers++;
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return;
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}
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FnStats.TotalVarWithLoc += (unsigned)HasLoc;
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if (Die.find(dwarf::DW_AT_artificial)) {
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FnStats.NumArtificial++;
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return;
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}
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if (IsParam) {
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FnStats.NumParams++;
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if (HasType)
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FnStats.NumParamTypes++;
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if (HasSrcLoc)
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FnStats.NumParamSourceLocations++;
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if (HasLoc)
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FnStats.NumParamLocations++;
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} else if (IsLocalVar) {
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FnStats.NumLocalVars++;
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if (HasType)
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FnStats.NumLocalVarTypes++;
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if (HasSrcLoc)
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FnStats.NumLocalVarSourceLocations++;
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if (HasLoc)
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FnStats.NumLocalVarLocations++;
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}
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}
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/// Recursively collect variables from subprogram with
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/// DW_AT_inline attribute.
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static void collectInlinedFnInfo(DWARFDie Die,
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uint64_t SPOffset,
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InlinedVarsTyMap &GlobalInlinedFnInfo) {
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DWARFDie Child = Die.getFirstChild();
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while (Child) {
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const dwarf::Tag ChildTag = Child.getTag();
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if (ChildTag == dwarf::DW_TAG_formal_parameter ||
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ChildTag == dwarf::DW_TAG_variable)
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GlobalInlinedFnInfo[SPOffset].push_back(Child.getOffset());
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else if (ChildTag == dwarf::DW_TAG_lexical_block)
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collectInlinedFnInfo(Child, SPOffset, GlobalInlinedFnInfo);
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Child = Child.getSibling();
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}
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}
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/// Recursively collect debug info quality metrics.
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static void collectStatsRecursive(DWARFDie Die, std::string FnPrefix,
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std::string VarPrefix, uint64_t BytesInScope,
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uint32_t InlineDepth,
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StringMap<PerFunctionStats> &FnStatMap,
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GlobalStats &GlobalStats,
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LocationStats &LocStats,
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InlinedVarsTyMap &GlobalInlinedFnInfo,
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InlinedFnInstacesTy &InlinedFnsToBeProcessed,
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InlinedVarsTy *InlinedVarsPtr = nullptr) {
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// Skip NULL nodes.
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if (Die.isNULL())
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return;
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const dwarf::Tag Tag = Die.getTag();
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// Skip function types.
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if (Tag == dwarf::DW_TAG_subroutine_type)
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return;
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// Handle any kind of lexical scope.
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const bool IsFunction = Tag == dwarf::DW_TAG_subprogram;
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const bool IsBlock = Tag == dwarf::DW_TAG_lexical_block;
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const bool IsInlinedFunction = Tag == dwarf::DW_TAG_inlined_subroutine;
|
|
InlinedVarsTy InlinedVars;
|
|
// Get the vars of the inlined fn, so the locstats
|
|
// reports the missing vars (with coverage 0%).
|
|
if (IsInlinedFunction) {
|
|
auto OffsetFn = Die.find(dwarf::DW_AT_abstract_origin);
|
|
if (OffsetFn) {
|
|
uint64_t OffsetOfInlineFnCopy = (*OffsetFn).getRawUValue();
|
|
if (GlobalInlinedFnInfo.count(OffsetOfInlineFnCopy)) {
|
|
InlinedVars = GlobalInlinedFnInfo[OffsetOfInlineFnCopy];
|
|
InlinedVarsPtr = &InlinedVars;
|
|
} else {
|
|
// This means that the DW_AT_inline fn copy is out of order,
|
|
// so this inlined instance will be processed later.
|
|
InlinedFnsToBeProcessed.push_back(Die.getOffset());
|
|
InlinedVarsPtr = nullptr;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (IsFunction || IsInlinedFunction || IsBlock) {
|
|
// Reset VarPrefix when entering a new function.
|
|
if (IsFunction || IsInlinedFunction)
|
|
VarPrefix = "v";
|
|
|
|
// Ignore forward declarations.
|
|
if (Die.find(dwarf::DW_AT_declaration))
|
|
return;
|
|
|
|
// Check for call sites.
|
|
if (Die.find(dwarf::DW_AT_call_file) && Die.find(dwarf::DW_AT_call_line))
|
|
GlobalStats.CallSiteEntries++;
|
|
|
|
// PC Ranges.
|
|
auto RangesOrError = Die.getAddressRanges();
|
|
if (!RangesOrError) {
|
|
llvm::consumeError(RangesOrError.takeError());
|
|
return;
|
|
}
|
|
|
|
auto Ranges = RangesOrError.get();
|
|
uint64_t BytesInThisScope = 0;
|
|
for (auto Range : Ranges)
|
|
BytesInThisScope += Range.HighPC - Range.LowPC;
|
|
|
|
// Count the function.
|
|
if (!IsBlock) {
|
|
// Skip over abstract origins, but collect variables
|
|
// from it so it can be used for location statistics
|
|
// for inlined instancies.
|
|
if (Die.find(dwarf::DW_AT_inline)) {
|
|
uint64_t SPOffset = Die.getOffset();
|
|
collectInlinedFnInfo(Die, SPOffset, GlobalInlinedFnInfo);
|
|
return;
|
|
}
|
|
|
|
std::string FnID = constructDieID(Die);
|
|
// We've seen an instance of this function.
|
|
auto &FnStats = FnStatMap[FnID];
|
|
FnStats.IsFunction = true;
|
|
if (IsInlinedFunction) {
|
|
FnStats.NumFnInlined++;
|
|
if (Die.findRecursively(dwarf::DW_AT_abstract_origin))
|
|
FnStats.NumAbstractOrigins++;
|
|
} else {
|
|
FnStats.NumFnOutOfLine++;
|
|
}
|
|
if (Die.findRecursively(dwarf::DW_AT_decl_file) &&
|
|
Die.findRecursively(dwarf::DW_AT_decl_line))
|
|
FnStats.HasSourceLocation = true;
|
|
// Update function prefix.
|
|
FnPrefix = FnID;
|
|
}
|
|
|
|
if (BytesInThisScope) {
|
|
BytesInScope = BytesInThisScope;
|
|
if (IsFunction)
|
|
GlobalStats.FunctionSize += BytesInThisScope;
|
|
else if (IsInlinedFunction && InlineDepth == 0)
|
|
GlobalStats.InlineFunctionSize += BytesInThisScope;
|
|
}
|
|
} else {
|
|
// Not a scope, visit the Die itself. It could be a variable.
|
|
collectStatsForDie(Die, FnPrefix, VarPrefix, BytesInScope, InlineDepth,
|
|
FnStatMap, GlobalStats, LocStats, InlinedVarsPtr);
|
|
}
|
|
|
|
// Set InlineDepth correctly for child recursion
|
|
if (IsFunction)
|
|
InlineDepth = 0;
|
|
else if (IsInlinedFunction)
|
|
++InlineDepth;
|
|
|
|
// Traverse children.
|
|
unsigned LexicalBlockIndex = 0;
|
|
unsigned FormalParameterIndex = 0;
|
|
DWARFDie Child = Die.getFirstChild();
|
|
while (Child) {
|
|
std::string ChildVarPrefix = VarPrefix;
|
|
if (Child.getTag() == dwarf::DW_TAG_lexical_block)
|
|
ChildVarPrefix += toHex(LexicalBlockIndex++) + '.';
|
|
if (Child.getTag() == dwarf::DW_TAG_formal_parameter)
|
|
ChildVarPrefix += 'p' + toHex(FormalParameterIndex++) + '.';
|
|
|
|
collectStatsRecursive(Child, FnPrefix, ChildVarPrefix, BytesInScope,
|
|
InlineDepth, FnStatMap, GlobalStats, LocStats,
|
|
GlobalInlinedFnInfo, InlinedFnsToBeProcessed,
|
|
InlinedVarsPtr);
|
|
Child = Child.getSibling();
|
|
}
|
|
|
|
if (!IsInlinedFunction)
|
|
return;
|
|
|
|
// After we have processed all vars of the inlined function,
|
|
// we want to know how many variables have no location.
|
|
for (auto Offset : InlinedVars) {
|
|
LocStats.NumVarParam++;
|
|
LocStats.VarParamLocStats[ZeroCoverageBucket]++;
|
|
auto InlineDie = Die.getDwarfUnit()->getDIEForOffset(Offset);
|
|
if (!InlineDie)
|
|
continue;
|
|
auto Tag = InlineDie.getTag();
|
|
if (Tag == dwarf::DW_TAG_formal_parameter) {
|
|
LocStats.NumParam++;
|
|
LocStats.ParamLocStats[ZeroCoverageBucket]++;
|
|
} else if (Tag == dwarf::DW_TAG_variable) {
|
|
LocStats.NumVar++;
|
|
LocStats.LocalVarLocStats[ZeroCoverageBucket]++;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Print human-readable output.
|
|
/// \{
|
|
static void printDatum(json::OStream &J, const char *Key, json::Value Value) {
|
|
J.attribute(Key, Value);
|
|
LLVM_DEBUG(llvm::dbgs() << Key << ": " << Value << '\n');
|
|
}
|
|
|
|
static void printLocationStats(json::OStream &J, const char *Key,
|
|
std::vector<unsigned> &LocationStats) {
|
|
J.attribute(
|
|
(Twine(Key) + " with 0% of parent scope covered by DW_AT_location").str(),
|
|
LocationStats[0]);
|
|
LLVM_DEBUG(
|
|
llvm::dbgs() << Key
|
|
<< " with 0% of parent scope covered by DW_AT_location: \\"
|
|
<< LocationStats[0] << '\n');
|
|
J.attribute(
|
|
(Twine(Key) + " with (0%,10%) of parent scope covered by DW_AT_location")
|
|
.str(),
|
|
LocationStats[1]);
|
|
LLVM_DEBUG(llvm::dbgs()
|
|
<< Key
|
|
<< " with (0%,10%) of parent scope covered by DW_AT_location: "
|
|
<< LocationStats[1] << '\n');
|
|
for (unsigned i = 2; i < NumOfCoverageCategories - 1; ++i) {
|
|
J.attribute((Twine(Key) + " with [" + Twine((i - 1) * 10) + "%," +
|
|
Twine(i * 10) + "%) of parent scope covered by DW_AT_location")
|
|
.str(),
|
|
LocationStats[i]);
|
|
LLVM_DEBUG(llvm::dbgs()
|
|
<< Key << " with [" << (i - 1) * 10 << "%," << i * 10
|
|
<< "%) of parent scope covered by DW_AT_location: "
|
|
<< LocationStats[i]);
|
|
}
|
|
J.attribute(
|
|
(Twine(Key) + " with 100% of parent scope covered by DW_AT_location")
|
|
.str(),
|
|
LocationStats[NumOfCoverageCategories - 1]);
|
|
LLVM_DEBUG(
|
|
llvm::dbgs() << Key
|
|
<< " with 100% of parent scope covered by DW_AT_location: "
|
|
<< LocationStats[NumOfCoverageCategories - 1]);
|
|
}
|
|
|
|
static void printSectionSizes(json::OStream &J, const SectionSizes &Sizes) {
|
|
for (const auto &It : Sizes.DebugSectionSizes)
|
|
J.attribute((Twine("#bytes in ") + It.first).str(), int64_t(It.second));
|
|
}
|
|
|
|
/// Stop tracking inlined variables with a location.
|
|
/// This is used for out-of-order DW_AT_inline subprograms only.
|
|
static void updateInlinedVarsCovInfo(DWARFDie InlinedFnDie,
|
|
InlinedVarsTy &InlinedVars) {
|
|
DWARFDie Child = InlinedFnDie.getFirstChild();
|
|
while (Child) {
|
|
const dwarf::Tag ChildTag = Child.getTag();
|
|
if ((ChildTag == dwarf::DW_TAG_formal_parameter ||
|
|
ChildTag == dwarf::DW_TAG_variable) &&
|
|
(Child.find(dwarf::DW_AT_location) ||
|
|
Child.find(dwarf::DW_AT_const_value))) {
|
|
auto OffsetVar = Child.find(dwarf::DW_AT_abstract_origin);
|
|
if (OffsetVar)
|
|
llvm::erase_value(InlinedVars, (*OffsetVar).getRawUValue());
|
|
} else if (ChildTag == dwarf::DW_TAG_lexical_block)
|
|
updateInlinedVarsCovInfo(Child, InlinedVars);
|
|
Child = Child.getSibling();
|
|
}
|
|
}
|
|
|
|
/// Collect zero location coverage for inlined variables which refer to
|
|
/// a DW_AT_inline copy of subprogram that is out of order in the DWARF.
|
|
static void
|
|
collectZeroCovInlinedVars(DWARFUnit *DwUnit, GlobalStats &GlobalStats,
|
|
LocationStats &LocStats,
|
|
InlinedVarsTyMap &GlobalInlinedFnInfo,
|
|
InlinedFnInstacesTy &InlinedFnsToBeProcessed) {
|
|
for (auto FnOffset : InlinedFnsToBeProcessed) {
|
|
DWARFDie InlinedFnDie = DwUnit->getDIEForOffset(FnOffset);
|
|
auto InlinedCopy = InlinedFnDie.find(dwarf::DW_AT_abstract_origin);
|
|
InlinedVarsTy InlinedVars;
|
|
if (!InlinedCopy)
|
|
continue;
|
|
|
|
InlinedVars = GlobalInlinedFnInfo[(*InlinedCopy).getRawUValue()];
|
|
updateInlinedVarsCovInfo(InlinedFnDie, InlinedVars);
|
|
|
|
for (auto Offset : InlinedVars) {
|
|
LocStats.NumVarParam++;
|
|
LocStats.VarParamLocStats[ZeroCoverageBucket]++;
|
|
auto Tag = DwUnit->getDIEForOffset(Offset).getTag();
|
|
if (Tag == dwarf::DW_TAG_formal_parameter) {
|
|
LocStats.NumParam++;
|
|
LocStats.ParamLocStats[ZeroCoverageBucket]++;
|
|
} else if (Tag == dwarf::DW_TAG_variable) {
|
|
LocStats.NumVar++;
|
|
LocStats.LocalVarLocStats[ZeroCoverageBucket]++;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// \}
|
|
|
|
/// Collect debug info quality metrics for an entire DIContext.
|
|
///
|
|
/// Do the impossible and reduce the quality of the debug info down to a few
|
|
/// numbers. The idea is to condense the data into numbers that can be tracked
|
|
/// over time to identify trends in newer compiler versions and gauge the effect
|
|
/// of particular optimizations. The raw numbers themselves are not particularly
|
|
/// useful, only the delta between compiling the same program with different
|
|
/// compilers is.
|
|
bool dwarfdump::collectStatsForObjectFile(ObjectFile &Obj, DWARFContext &DICtx,
|
|
const Twine &Filename,
|
|
raw_ostream &OS) {
|
|
StringRef FormatName = Obj.getFileFormatName();
|
|
GlobalStats GlobalStats;
|
|
LocationStats LocStats;
|
|
InlinedVarsTyMap GlobalInlinedFnInfo;
|
|
InlinedFnInstacesTy InlinedFnsToBeProcessed;
|
|
StringMap<PerFunctionStats> Statistics;
|
|
for (const auto &CU : static_cast<DWARFContext *>(&DICtx)->compile_units()) {
|
|
if (DWARFDie CUDie = CU->getNonSkeletonUnitDIE(false)) {
|
|
collectStatsRecursive(CUDie, "/", "g", 0, 0, Statistics, GlobalStats,
|
|
LocStats, GlobalInlinedFnInfo,
|
|
InlinedFnsToBeProcessed);
|
|
|
|
collectZeroCovInlinedVars(CUDie.getDwarfUnit(), GlobalStats, LocStats,
|
|
GlobalInlinedFnInfo, InlinedFnsToBeProcessed);
|
|
}
|
|
}
|
|
|
|
/// Collect the sizes of debug sections.
|
|
SectionSizes Sizes;
|
|
calculateSectionSizes(Obj, Sizes, Filename);
|
|
|
|
/// The version number should be increased every time the algorithm is changed
|
|
/// (including bug fixes). New metrics may be added without increasing the
|
|
/// version.
|
|
unsigned Version = 7;
|
|
unsigned VarParamTotal = 0;
|
|
unsigned VarParamUnique = 0;
|
|
unsigned VarParamWithLoc = 0;
|
|
unsigned NumFunctions = 0;
|
|
unsigned NumInlinedFunctions = 0;
|
|
unsigned NumFuncsWithSrcLoc = 0;
|
|
unsigned NumAbstractOrigins = 0;
|
|
unsigned ParamTotal = 0;
|
|
unsigned ParamWithType = 0;
|
|
unsigned ParamWithLoc = 0;
|
|
unsigned ParamWithSrcLoc = 0;
|
|
unsigned LocalVarTotal = 0;
|
|
unsigned LocalVarWithType = 0;
|
|
unsigned LocalVarWithSrcLoc = 0;
|
|
unsigned LocalVarWithLoc = 0;
|
|
for (auto &Entry : Statistics) {
|
|
PerFunctionStats &Stats = Entry.getValue();
|
|
unsigned TotalVars = Stats.VarsInFunction.size() *
|
|
(Stats.NumFnInlined + Stats.NumFnOutOfLine);
|
|
// Count variables in global scope.
|
|
if (!Stats.IsFunction)
|
|
TotalVars =
|
|
Stats.NumLocalVars + Stats.ConstantMembers + Stats.NumArtificial;
|
|
unsigned Constants = Stats.ConstantMembers;
|
|
VarParamWithLoc += Stats.TotalVarWithLoc + Constants;
|
|
VarParamTotal += TotalVars;
|
|
VarParamUnique += Stats.VarsInFunction.size();
|
|
LLVM_DEBUG(for (auto &V
|
|
: Stats.VarsInFunction) llvm::dbgs()
|
|
<< Entry.getKey() << ": " << V.getKey() << "\n");
|
|
NumFunctions += Stats.IsFunction;
|
|
NumFuncsWithSrcLoc += Stats.HasSourceLocation;
|
|
NumInlinedFunctions += Stats.IsFunction * Stats.NumFnInlined;
|
|
NumAbstractOrigins += Stats.IsFunction * Stats.NumAbstractOrigins;
|
|
ParamTotal += Stats.NumParams;
|
|
ParamWithType += Stats.NumParamTypes;
|
|
ParamWithLoc += Stats.NumParamLocations;
|
|
ParamWithSrcLoc += Stats.NumParamSourceLocations;
|
|
LocalVarTotal += Stats.NumLocalVars;
|
|
LocalVarWithType += Stats.NumLocalVarTypes;
|
|
LocalVarWithLoc += Stats.NumLocalVarLocations;
|
|
LocalVarWithSrcLoc += Stats.NumLocalVarSourceLocations;
|
|
}
|
|
|
|
// Print summary.
|
|
OS.SetBufferSize(1024);
|
|
json::OStream J(OS, 2);
|
|
J.objectBegin();
|
|
J.attribute("version", Version);
|
|
LLVM_DEBUG(llvm::dbgs() << "Variable location quality metrics\n";
|
|
llvm::dbgs() << "---------------------------------\n");
|
|
|
|
printDatum(J, "file", Filename.str());
|
|
printDatum(J, "format", FormatName);
|
|
|
|
printDatum(J, "#functions", NumFunctions);
|
|
printDatum(J, "#functions with location", NumFuncsWithSrcLoc);
|
|
printDatum(J, "#inlined functions", NumInlinedFunctions);
|
|
printDatum(J, "#inlined functions with abstract origins", NumAbstractOrigins);
|
|
|
|
// This includes local variables and formal parameters.
|
|
printDatum(J, "#unique source variables", VarParamUnique);
|
|
printDatum(J, "#source variables", VarParamTotal);
|
|
printDatum(J, "#source variables with location", VarParamWithLoc);
|
|
|
|
printDatum(J, "#call site entries", GlobalStats.CallSiteEntries);
|
|
printDatum(J, "#call site DIEs", GlobalStats.CallSiteDIEs);
|
|
printDatum(J, "#call site parameter DIEs", GlobalStats.CallSiteParamDIEs);
|
|
|
|
printDatum(J, "sum_all_variables(#bytes in parent scope)",
|
|
GlobalStats.ScopeBytes);
|
|
printDatum(J,
|
|
"sum_all_variables(#bytes in any scope covered by DW_AT_location)",
|
|
GlobalStats.TotalBytesCovered);
|
|
printDatum(J,
|
|
"sum_all_variables(#bytes in parent scope covered by "
|
|
"DW_AT_location)",
|
|
GlobalStats.ScopeBytesCovered);
|
|
printDatum(J,
|
|
"sum_all_variables(#bytes in parent scope covered by "
|
|
"DW_OP_entry_value)",
|
|
GlobalStats.ScopeEntryValueBytesCovered);
|
|
|
|
printDatum(J, "sum_all_params(#bytes in parent scope)",
|
|
GlobalStats.ParamScopeBytes);
|
|
printDatum(J,
|
|
"sum_all_params(#bytes in parent scope covered by DW_AT_location)",
|
|
GlobalStats.ParamScopeBytesCovered);
|
|
printDatum(J,
|
|
"sum_all_params(#bytes in parent scope covered by "
|
|
"DW_OP_entry_value)",
|
|
GlobalStats.ParamScopeEntryValueBytesCovered);
|
|
|
|
printDatum(J, "sum_all_local_vars(#bytes in parent scope)",
|
|
GlobalStats.LocalVarScopeBytes);
|
|
printDatum(J,
|
|
"sum_all_local_vars(#bytes in parent scope covered by "
|
|
"DW_AT_location)",
|
|
GlobalStats.LocalVarScopeBytesCovered);
|
|
printDatum(J,
|
|
"sum_all_local_vars(#bytes in parent scope covered by "
|
|
"DW_OP_entry_value)",
|
|
GlobalStats.LocalVarScopeEntryValueBytesCovered);
|
|
|
|
printDatum(J, "#bytes within functions", GlobalStats.FunctionSize);
|
|
printDatum(J, "#bytes within inlined functions",
|
|
GlobalStats.InlineFunctionSize);
|
|
|
|
// Print the summary for formal parameters.
|
|
printDatum(J, "#params", ParamTotal);
|
|
printDatum(J, "#params with source location", ParamWithSrcLoc);
|
|
printDatum(J, "#params with type", ParamWithType);
|
|
printDatum(J, "#params with binary location", ParamWithLoc);
|
|
|
|
// Print the summary for local variables.
|
|
printDatum(J, "#local vars", LocalVarTotal);
|
|
printDatum(J, "#local vars with source location", LocalVarWithSrcLoc);
|
|
printDatum(J, "#local vars with type", LocalVarWithType);
|
|
printDatum(J, "#local vars with binary location", LocalVarWithLoc);
|
|
|
|
// Print the debug section sizes.
|
|
printSectionSizes(J, Sizes);
|
|
|
|
// Print the location statistics for variables (includes local variables
|
|
// and formal parameters).
|
|
printDatum(J, "#variables processed by location statistics",
|
|
LocStats.NumVarParam);
|
|
printLocationStats(J, "#variables", LocStats.VarParamLocStats);
|
|
printLocationStats(J, "#variables - entry values",
|
|
LocStats.VarParamNonEntryValLocStats);
|
|
|
|
// Print the location statistics for formal parameters.
|
|
printDatum(J, "#params processed by location statistics", LocStats.NumParam);
|
|
printLocationStats(J, "#params", LocStats.ParamLocStats);
|
|
printLocationStats(J, "#params - entry values",
|
|
LocStats.ParamNonEntryValLocStats);
|
|
|
|
// Print the location statistics for local variables.
|
|
printDatum(J, "#local vars processed by location statistics",
|
|
LocStats.NumVar);
|
|
printLocationStats(J, "#local vars", LocStats.LocalVarLocStats);
|
|
printLocationStats(J, "#local vars - entry values",
|
|
LocStats.LocalVarNonEntryValLocStats);
|
|
J.objectEnd();
|
|
OS << '\n';
|
|
LLVM_DEBUG(
|
|
llvm::dbgs() << "Total Availability: "
|
|
<< (int)std::round((VarParamWithLoc * 100.0) / VarParamTotal)
|
|
<< "%\n";
|
|
llvm::dbgs() << "PC Ranges covered: "
|
|
<< (int)std::round((GlobalStats.ScopeBytesCovered * 100.0) /
|
|
GlobalStats.ScopeBytes)
|
|
<< "%\n");
|
|
return true;
|
|
}
|