From 2dfb5da16b97a6c12e01977af5b5188522178a4e Mon Sep 17 00:00:00 2001 From: Stefan Boberg Date: Mon, 20 Apr 2026 21:50:41 +0200 Subject: zen trace analysis support (#945) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Integrates the **tourist** trace analysis library and builds a full `zen trace` command suite for working with Unreal Engine `.utrace` files. ### Trace analysis library (`thirdparty/tourist/`) - Adds the tourist library as a third-party dependency with three modules: **foundation** (platform primitives, memory, scheduling), **trace** (UE Trace protocol decoding), and **analysis** (event dispatching and analyzer framework). - Cross-platform support for Windows, Linux, and macOS. ### `zen trace` CLI commands (`src/zen/cmds/`, `src/zen/trace/`) - **`zen trace analyze`** — Summarize a `.utrace` file: session metadata, thread inventory, command line + build configuration, CPU profiling scopes, timing, event rates, log messages, and (with symbols) memory allocation metrics including live-allocs dumps, callstack-keyed aggregation, and allocation churn. Optional HTML output for memory reports. - **`zen trace inspect`** — Dump the event schema (declared types, fields, sizes) from a trace file. - **`zen trace trim`** — Extract a time-window from a trace into a new `.utrace` file. - **`zen trace serve`** — Launch a local HTTP server hosting an interactive trace viewer; opens in the default browser. ### Symbolication (`src/zen/trace/symbol_resolver.*`, `thirdparty/raw_pdb/`) - Pluggable resolver with multiple backends: `pdb` (in-tree raw_pdb), `dbghelp` (Windows), `llvm-symbolizer` (all platforms), `atos` (macOS). An `auto` backend picks the best available tool per platform. - Microsoft Symbol Server support: downloads PDBs on demand using a redirect-aware HTTP client. - Local PDB cache keyed by image GUID preserves symbols across binary recompilation. - Callstack trimming heuristic strips UE internal noise from reports. - Binary analysis cache (`.ucache_z`) avoids re-resolving the same trace. ### Interactive trace viewer (`src/zen/frontend/html/`, `src/zen/trace/trace_viewer_service.*`) - Timeline: scope-level detail, horizontal zoom/pan, vertical scrolling, viewport-driven loading with pre-computed LOD for responsive navigation of large traces. - Thread grouping (collapsible sidebar sections) synthesized from name suffixes, natural sort order, visual distinction between lane threads and OS threads. - Bookmark and region annotations; region categories with per-category toggles; bookmark marker toggle in the toolbar. - Filterable Logs tab showing captured `UE_LOG` output. - Stats tab with per-scope aggregate statistics. - Memory tab with interactive allocation analysis and an allocation size histogram. - CsvProfiler event parsing and chart UI. ### Other in-branch supporting changes - **Cross-platform browser launcher** (`browser_launcher.{h,cpp}`) used by `trace serve`. - **`ReciprocalU64`** fast 64-bit integer division (zencore/intmath) for trace analyzers. - **`parallelsort`** cross-platform parallel sort helper (zenutil). - Frontend zip build rule so the viewer's HTML assets are bundled into `zen.exe`. - `/Zo` flag for better optimized debug info on Windows release builds. - `trace-tests.cpp` in the `zen-test` harness (harness itself landed on main via #985). --- src/zen/trace/callstack_formatter.cpp | 251 ++++++++++++++++++++++++++++++++++ 1 file changed, 251 insertions(+) create mode 100644 src/zen/trace/callstack_formatter.cpp (limited to 'src/zen/trace/callstack_formatter.cpp') diff --git a/src/zen/trace/callstack_formatter.cpp b/src/zen/trace/callstack_formatter.cpp new file mode 100644 index 000000000..0c601d5c0 --- /dev/null +++ b/src/zen/trace/callstack_formatter.cpp @@ -0,0 +1,251 @@ +// Copyright Epic Games, Inc. All Rights Reserved. + +#include "callstack_formatter.h" + +#include +#include +#include + +#include + +namespace zen::trace_detail { + +namespace { + + static bool IsKnownRuntimeModuleName(std::string_view ModuleName) + { + std::string LowerName = zen::ToLower(ModuleName); + return LowerName == "ntdll.dll" || LowerName == "kernel32.dll" || LowerName == "kernelbase.dll" || LowerName == "ucrtbase.dll" || + LowerName == "ucrtbased.dll" || LowerName.starts_with("vcruntime") || LowerName.starts_with("msvcp") || + LowerName.starts_with("api-ms-win-") || LowerName == "libc.so" || LowerName.starts_with("libc.so.") || + LowerName == "libstdc++.so" || LowerName.starts_with("libstdc++.so.") || LowerName == "libgcc_s.so" || + LowerName.starts_with("libgcc_s.so.") || LowerName == "libpthread.so" || LowerName.starts_with("libpthread.so.") || + LowerName == "libm.so" || LowerName.starts_with("libm.so.") || LowerName == "ld-linux.so" || + LowerName.starts_with("ld-linux") || LowerName == "libsystem_kernel.dylib" || LowerName == "libsystem_malloc.dylib" || + LowerName == "libsystem_pthread.dylib" || LowerName == "libdyld.dylib"; + } + + static bool PathLooksThirdParty(std::string_view ModulePath) + { + std::string LowerPath = zen::ToLower(ModulePath); + return LowerPath.find("/thirdparty/") != std::string::npos || LowerPath.find("\\thirdparty\\") != std::string::npos || + LowerPath.find("/third-party/") != std::string::npos || LowerPath.find("\\third-party\\") != std::string::npos || + LowerPath.find("/external/") != std::string::npos || LowerPath.find("\\external\\") != std::string::npos || + LowerPath.find("/extern/") != std::string::npos || LowerPath.find("\\extern\\") != std::string::npos || + LowerPath.find("/engine/binaries/thirdparty/") != std::string::npos || + LowerPath.find("\\engine\\binaries\\thirdparty\\") != std::string::npos || + LowerPath.find("c:\\windows\\system32\\") != std::string::npos || + LowerPath.find("c:\\windows\\syswow64\\") != std::string::npos || LowerPath.starts_with("/usr/lib/") || + LowerPath.starts_with("/lib/") || LowerPath.starts_with("/system/"); + } + + static bool MatchesAnyPattern(std::string_view Text, const std::vector& Patterns) + { + for (const std::string& Pattern : Patterns) + { + if (zen::MatchWildcard(Pattern, Text, /*CaseSensitive=*/false)) + { + return true; + } + } + return false; + } + + static bool ShouldSkipFrameByPattern(const CallstackFilterOptions& Options, + const TraceModel& Model, + const ResolvedFrame& Frame, + std::string_view Description) + { + if (MatchesAnyPattern(Description, Options.SkipPatterns)) + { + return true; + } + if (Frame.ModuleIndex != ~0u && Frame.ModuleIndex < Model.Modules.size()) + { + const ModuleInfo& Module = Model.Modules[Frame.ModuleIndex]; + if (MatchesAnyPattern(Module.Name, Options.SkipPatterns) || MatchesAnyPattern(Module.FullPath, Options.SkipPatterns)) + { + return true; + } + } + + static const std::vector kDefaultSkipPatterns = { + "zen::MemoryTrace_*", + "*mi_*", + "*_mi_*", + "*rpmalloc*", + "*mimalloc*", + "*je_malloc*", + "*je_free*", + "*malloc*", + "*free*", + "*realloc*", + }; + return MatchesAnyPattern(Description, kDefaultSkipPatterns); + } + + static bool IsThirdPartyFrame(const TraceModel& Model, const ResolvedFrame& Frame, std::string_view Description) + { + if (Description.starts_with("std::")) + { + return true; + } + if (Frame.ModuleIndex == ~0u || Frame.ModuleIndex >= Model.Modules.size()) + { + return false; + } + + const ModuleInfo& Module = Model.Modules[Frame.ModuleIndex]; + return IsKnownRuntimeModuleName(Module.Name) || PathLooksThirdParty(Module.FullPath); + } + +} // namespace + +CallstackFormatter::CallstackFormatter(const TraceModel& InModel, const SymbolResolver* InSymbols) : m_Model(InModel), m_Symbols(InSymbols) +{ +} + +const CallstackEntry* +CallstackFormatter::FindCallstackEntry(uint32_t CallstackId) const +{ + auto It = + eastl::lower_bound(m_Model.Callstacks.begin(), m_Model.Callstacks.end(), CallstackId, [](const CallstackEntry& E, uint32_t Id) { + return E.Id < Id; + }); + if (It == m_Model.Callstacks.end() || It->Id != CallstackId) + { + return nullptr; + } + return &*It; +} + +const std::string& +CallstackFormatter::Describe(const ResolvedFrame& Frame) +{ + auto It = m_Cache.find(Frame.Address); + if (It != m_Cache.end()) + { + return It->second; + } + + std::string Result = m_Symbols ? m_Symbols->Resolve(Frame.Address) : std::string{}; + if (Result.empty()) + { + if (Frame.ModuleIndex != ~0u && Frame.ModuleIndex < m_Model.Modules.size()) + { + Result = fmt::format("{} + 0x{:X}", m_Model.Modules[Frame.ModuleIndex].Name, Frame.Offset); + } + else + { + Result = fmt::format("0x{:X}", Frame.Address); + } + } + + auto [InsertedIt, Inserted] = m_Cache.emplace(Frame.Address, std::move(Result)); + ZEN_UNUSED(Inserted); + return InsertedIt->second; +} + +FilteredCallstackView +CallstackFormatter::BuildView(const CallstackEntry& Entry, const CallstackFilterOptions& Options) +{ + FilteredCallstackView Result; + Result.Frames.reserve(Entry.Frames.size()); + if (Entry.Frames.empty()) + { + return Result; + } + + eastl::vector ExplicitSkip; + eastl::vector ThirdParty; + ExplicitSkip.reserve(Entry.Frames.size()); + ThirdParty.reserve(Entry.Frames.size()); + + for (const ResolvedFrame& Frame : Entry.Frames) + { + const std::string& Description = Describe(Frame); + ExplicitSkip.push_back(ShouldSkipFrameByPattern(Options, m_Model, Frame, Description)); + ThirdParty.push_back(IsThirdPartyFrame(m_Model, Frame, Description)); + } + + eastl::vector VisibleFrameIndices; + VisibleFrameIndices.reserve(Entry.Frames.size()); + + if (!Options.EnableHeuristic) + { + for (size_t Index = 0; Index < Entry.Frames.size(); ++Index) + { + if (!ExplicitSkip[Index]) + { + VisibleFrameIndices.push_back(Index); + } + } + if (VisibleFrameIndices.empty()) + { + VisibleFrameIndices.push_back(0); + } + } + else + { + size_t FirstProgramIndex = Entry.Frames.size(); + size_t BoundaryThirdPartyIndex = Entry.Frames.size(); + for (size_t Index = 0; Index < Entry.Frames.size(); ++Index) + { + if (ExplicitSkip[Index]) + { + continue; + } + if (ThirdParty[Index]) + { + BoundaryThirdPartyIndex = Index; + continue; + } + FirstProgramIndex = Index; + break; + } + + if (FirstProgramIndex == Entry.Frames.size()) + { + for (size_t Index = 0; Index < Entry.Frames.size(); ++Index) + { + if (!ExplicitSkip[Index]) + { + VisibleFrameIndices.push_back(Index); + } + } + if (VisibleFrameIndices.empty()) + { + VisibleFrameIndices.push_back(0); + } + } + else + { + if (BoundaryThirdPartyIndex < Entry.Frames.size()) + { + VisibleFrameIndices.push_back(BoundaryThirdPartyIndex); + Result.IncludedThirdPartyBoundary = true; + } + for (size_t Index = FirstProgramIndex; Index < Entry.Frames.size(); ++Index) + { + if (!ExplicitSkip[Index]) + { + VisibleFrameIndices.push_back(Index); + } + } + if (VisibleFrameIndices.empty()) + { + VisibleFrameIndices.push_back(FirstProgramIndex); + } + } + } + + Result.HiddenPrefixCount = uint32_t(VisibleFrameIndices.front()); + for (size_t FrameIndex : VisibleFrameIndices) + { + Result.Frames.push_back( + {.OriginalIndex = FrameIndex, .Frame = &Entry.Frames[FrameIndex], .Display = Describe(Entry.Frames[FrameIndex])}); + } + return Result; +} + +} // namespace zen::trace_detail -- cgit v1.2.3