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			794 lines
		
	
	
		
			31 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			794 lines
		
	
	
		
			31 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===- xray-stacks.cpp: XRay Function Call Stack Accounting ---------------===//
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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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| //
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| // This file implements stack-based accounting. It takes XRay traces, and
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| // collates statistics across these traces to show a breakdown of time spent
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| // at various points of the stack to provide insight into which functions
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| // spend the most time in terms of a call stack. We provide a few
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| // sorting/filtering options for zero'ing in on the useful stacks.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #include <forward_list>
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| #include <numeric>
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| 
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| #include "func-id-helper.h"
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| #include "trie-node.h"
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| #include "xray-registry.h"
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| #include "llvm/ADT/StringExtras.h"
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| #include "llvm/Support/CommandLine.h"
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| #include "llvm/Support/Errc.h"
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| #include "llvm/Support/ErrorHandling.h"
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| #include "llvm/Support/FormatAdapters.h"
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| #include "llvm/Support/FormatVariadic.h"
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| #include "llvm/XRay/Graph.h"
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| #include "llvm/XRay/InstrumentationMap.h"
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| #include "llvm/XRay/Trace.h"
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| 
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| using namespace llvm;
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| using namespace llvm::xray;
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| 
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| static cl::SubCommand Stack("stack", "Call stack accounting");
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| static cl::list<std::string> StackInputs(cl::Positional,
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|                                          cl::desc("<xray trace>"), cl::Required,
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|                                          cl::sub(Stack), cl::OneOrMore);
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| 
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| static cl::opt<bool>
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|     StackKeepGoing("keep-going", cl::desc("Keep going on errors encountered"),
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|                    cl::sub(Stack), cl::init(false));
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| static cl::alias StackKeepGoing2("k", cl::aliasopt(StackKeepGoing),
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|                                  cl::desc("Alias for -keep-going"));
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| 
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| // TODO: Does there need to be an option to deduce tail or sibling calls?
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| 
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| static cl::opt<std::string> StacksInstrMap(
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|     "instr_map",
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|     cl::desc("instrumentation map used to identify function ids. "
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|              "Currently supports elf file instrumentation maps."),
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|     cl::sub(Stack), cl::init(""));
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| static cl::alias StacksInstrMap2("m", cl::aliasopt(StacksInstrMap),
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|                                  cl::desc("Alias for -instr_map"));
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| 
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| static cl::opt<bool>
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|     SeparateThreadStacks("per-thread-stacks",
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|                          cl::desc("Report top stacks within each thread id"),
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|                          cl::sub(Stack), cl::init(false));
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| 
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| static cl::opt<bool>
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|     AggregateThreads("aggregate-threads",
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|                      cl::desc("Aggregate stack times across threads"),
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|                      cl::sub(Stack), cl::init(false));
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| 
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| static cl::opt<bool>
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|     DumpAllStacks("all-stacks",
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|                   cl::desc("Dump sum of timings for all stacks. "
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|                            "By default separates stacks per-thread."),
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|                   cl::sub(Stack), cl::init(false));
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| static cl::alias DumpAllStacksShort("all", cl::aliasopt(DumpAllStacks),
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|                                     cl::desc("Alias for -all-stacks"));
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| 
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| // TODO(kpw): Add other interesting formats. Perhaps chrome trace viewer format
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| // possibly with aggregations or just a linear trace of timings.
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| enum StackOutputFormat { HUMAN, FLAMETOOL };
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| 
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| static cl::opt<StackOutputFormat> StacksOutputFormat(
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|     "stack-format",
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|     cl::desc("The format that output stacks should be "
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|              "output in. Only applies with all-stacks."),
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|     cl::values(
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|         clEnumValN(HUMAN, "human",
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|                    "Human readable output. Only valid without -all-stacks."),
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|         clEnumValN(FLAMETOOL, "flame",
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|                    "Format consumable by Brendan Gregg's FlameGraph tool. "
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|                    "Only valid with -all-stacks.")),
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|     cl::sub(Stack), cl::init(HUMAN));
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| 
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| // Types of values for each stack in a CallTrie.
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| enum class AggregationType {
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|   TOTAL_TIME,      // The total time spent in a stack and its callees.
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|   INVOCATION_COUNT // The number of times the stack was invoked.
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| };
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| 
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| static cl::opt<AggregationType> RequestedAggregation(
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|     "aggregation-type",
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|     cl::desc("The type of aggregation to do on call stacks."),
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|     cl::values(
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|         clEnumValN(
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|             AggregationType::TOTAL_TIME, "time",
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|             "Capture the total time spent in an all invocations of a stack."),
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|         clEnumValN(AggregationType::INVOCATION_COUNT, "count",
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|                    "Capture the number of times a stack was invoked. "
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|                    "In flamegraph mode, this count also includes invocations "
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|                    "of all callees.")),
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|     cl::sub(Stack), cl::init(AggregationType::TOTAL_TIME));
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| 
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| /// A helper struct to work with formatv and XRayRecords. Makes it easier to
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| /// use instrumentation map names or addresses in formatted output.
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| struct format_xray_record : public FormatAdapter<XRayRecord> {
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|   explicit format_xray_record(XRayRecord record,
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|                               const FuncIdConversionHelper &conv)
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|       : FormatAdapter<XRayRecord>(std::move(record)), Converter(&conv) {}
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|   void format(raw_ostream &Stream, StringRef Style) override {
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|     Stream << formatv(
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|         "{FuncId: \"{0}\", ThreadId: \"{1}\", RecordType: \"{2}\"}",
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|         Converter->SymbolOrNumber(Item.FuncId), Item.TId,
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|         DecodeRecordType(Item.RecordType));
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|   }
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| 
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| private:
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|   Twine DecodeRecordType(uint16_t recordType) {
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|     switch (recordType) {
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|     case 0:
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|       return Twine("Fn Entry");
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|     case 1:
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|       return Twine("Fn Exit");
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|     default:
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|       // TODO: Add Tail exit when it is added to llvm/XRay/XRayRecord.h
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|       return Twine("Unknown");
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|     }
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|   }
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| 
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|   const FuncIdConversionHelper *Converter;
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| };
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| 
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| /// The stack command will take a set of XRay traces as arguments, and collects
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| /// information about the stacks of instrumented functions that appear in the
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| /// traces. We track the following pieces of information:
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| ///
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| ///   - Total time: amount of time/cycles accounted for in the traces.
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| ///   - Stack count: number of times a specific stack appears in the
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| ///     traces. Only instrumented functions show up in stacks.
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| ///   - Cumulative stack time: amount of time spent in a stack accumulated
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| ///     across the invocations in the traces.
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| ///   - Cumulative local time: amount of time spent in each instrumented
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| ///     function showing up in a specific stack, accumulated across the traces.
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| ///
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| /// Example output for the kind of data we'd like to provide looks like the
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| /// following:
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| ///
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| ///   Total time: 3.33234 s
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| ///   Stack ID: ...
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| ///   Stack Count: 2093
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| ///   #     Function                  Local Time     (%)      Stack Time     (%)
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| ///   0     main                         2.34 ms   0.07%      3.33234  s    100%
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| ///   1     foo()                     3.30000  s  99.02%         3.33  s  99.92%
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| ///   2     bar()                          30 ms   0.90%           30 ms   0.90%
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| ///
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| /// We can also show distributions of the function call durations with
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| /// statistics at each level of the stack. This works by doing the following
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| /// algorithm:
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| ///
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| ///   1. When unwinding, record the duration of each unwound function associated
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| ///   with the path up to which the unwinding stops. For example:
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| ///
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| ///        Step                         Duration (? means has start time)
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| ///
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| ///        push a <start time>           a = ?
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| ///        push b <start time>           a = ?, a->b = ?
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| ///        push c <start time>           a = ?, a->b = ?, a->b->c = ?
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| ///        pop  c <end time>             a = ?, a->b = ?, emit duration(a->b->c)
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| ///        pop  b <end time>             a = ?, emit duration(a->b)
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| ///        push c <start time>           a = ?, a->c = ?
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| ///        pop  c <end time>             a = ?, emit duration(a->c)
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| ///        pop  a <end time>             emit duration(a)
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| ///
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| ///   2. We then account for the various stacks we've collected, and for each of
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| ///      them will have measurements that look like the following (continuing
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| ///      with the above simple example):
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| ///
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| ///        c : [<id("a->b->c"), [durations]>, <id("a->c"), [durations]>]
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| ///        b : [<id("a->b"), [durations]>]
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| ///        a : [<id("a"), [durations]>]
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| ///
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| ///      This allows us to compute, for each stack id, and each function that
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| ///      shows up in the stack,  some important statistics like:
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| ///
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| ///        - median
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| ///        - 99th percentile
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| ///        - mean + stddev
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| ///        - count
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| ///
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| ///   3. For cases where we don't have durations for some of the higher levels
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| ///   of the stack (perhaps instrumentation wasn't activated when the stack was
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| ///   entered), we can mark them appropriately.
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| ///
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| ///  Computing this data also allows us to implement lookup by call stack nodes,
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| ///  so that we can find functions that show up in multiple stack traces and
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| ///  show the statistical properties of that function in various contexts. We
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| ///  can compute information similar to the following:
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| ///
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| ///    Function: 'c'
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| ///    Stacks: 2 / 2
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| ///    Stack ID: ...
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| ///    Stack Count: ...
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| ///    #     Function  ...
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| ///    0     a         ...
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| ///    1     b         ...
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| ///    2     c         ...
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| ///
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| ///    Stack ID: ...
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| ///    Stack Count: ...
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| ///    #     Function  ...
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| ///    0     a         ...
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| ///    1     c         ...
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| ///    ----------------...
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| ///
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| ///    Function: 'b'
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| ///    Stacks:  1 / 2
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| ///    Stack ID: ...
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| ///    Stack Count: ...
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| ///    #     Function  ...
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| ///    0     a         ...
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| ///    1     b         ...
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| ///    2     c         ...
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| ///
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| ///
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| /// To do this we require a Trie data structure that will allow us to represent
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| /// all the call stacks of instrumented functions in an easily traversible
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| /// manner when we do the aggregations and lookups. For instrumented call
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| /// sequences like the following:
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| ///
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| ///   a()
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| ///    b()
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| ///     c()
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| ///     d()
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| ///    c()
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| ///
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| /// We will have a representation like so:
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| ///
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| ///   a -> b -> c
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| ///   |    |
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| ///   |    +--> d
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| ///   |
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| ///   +--> c
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| ///
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| /// We maintain a sequence of durations on the leaves and in the internal nodes
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| /// as we go through and process every record from the XRay trace. We also
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| /// maintain an index of unique functions, and provide a means of iterating
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| /// through all the instrumented call stacks which we know about.
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| 
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| struct StackDuration {
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|   llvm::SmallVector<int64_t, 4> TerminalDurations;
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|   llvm::SmallVector<int64_t, 4> IntermediateDurations;
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| };
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| 
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| StackDuration mergeStackDuration(const StackDuration &Left,
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|                                  const StackDuration &Right) {
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|   StackDuration Data{};
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|   Data.TerminalDurations.reserve(Left.TerminalDurations.size() +
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|                                  Right.TerminalDurations.size());
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|   Data.IntermediateDurations.reserve(Left.IntermediateDurations.size() +
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|                                      Right.IntermediateDurations.size());
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|   // Aggregate the durations.
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|   for (auto duration : Left.TerminalDurations)
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|     Data.TerminalDurations.push_back(duration);
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|   for (auto duration : Right.TerminalDurations)
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|     Data.TerminalDurations.push_back(duration);
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| 
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|   for (auto duration : Left.IntermediateDurations)
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|     Data.IntermediateDurations.push_back(duration);
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|   for (auto duration : Right.IntermediateDurations)
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|     Data.IntermediateDurations.push_back(duration);
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|   return Data;
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| }
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| 
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| using StackTrieNode = TrieNode<StackDuration>;
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| 
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| template <AggregationType AggType>
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| std::size_t GetValueForStack(const StackTrieNode *Node);
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| 
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| // When computing total time spent in a stack, we're adding the timings from
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| // its callees and the timings from when it was a leaf.
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| template <>
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| std::size_t
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| GetValueForStack<AggregationType::TOTAL_TIME>(const StackTrieNode *Node) {
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|   auto TopSum = std::accumulate(Node->ExtraData.TerminalDurations.begin(),
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|                                 Node->ExtraData.TerminalDurations.end(), 0uLL);
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|   return std::accumulate(Node->ExtraData.IntermediateDurations.begin(),
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|                          Node->ExtraData.IntermediateDurations.end(), TopSum);
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| }
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| 
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| // Calculates how many times a function was invoked.
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| // TODO: Hook up option to produce stacks
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| template <>
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| std::size_t
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| GetValueForStack<AggregationType::INVOCATION_COUNT>(const StackTrieNode *Node) {
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|   return Node->ExtraData.TerminalDurations.size() +
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|          Node->ExtraData.IntermediateDurations.size();
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| }
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| 
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| // Make sure there are implementations for each enum value.
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| template <AggregationType T> struct DependentFalseType : std::false_type {};
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| 
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| template <AggregationType AggType>
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| std::size_t GetValueForStack(const StackTrieNode *Node) {
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|   static_assert(DependentFalseType<AggType>::value,
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|                 "No implementation found for aggregation type provided.");
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|   return 0;
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| }
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| 
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| class StackTrie {
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|   // Avoid the magic number of 4 propagated through the code with an alias.
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|   // We use this SmallVector to track the root nodes in a call graph.
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|   using RootVector = SmallVector<StackTrieNode *, 4>;
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| 
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|   // We maintain pointers to the roots of the tries we see.
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|   DenseMap<uint32_t, RootVector> Roots;
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| 
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|   // We make sure all the nodes are accounted for in this list.
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|   std::forward_list<StackTrieNode> NodeStore;
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| 
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|   // A map of thread ids to pairs call stack trie nodes and their start times.
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|   DenseMap<uint32_t, SmallVector<std::pair<StackTrieNode *, uint64_t>, 8>>
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|       ThreadStackMap;
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| 
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|   StackTrieNode *createTrieNode(uint32_t ThreadId, int32_t FuncId,
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|                                 StackTrieNode *Parent) {
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|     NodeStore.push_front(StackTrieNode{FuncId, Parent, {}, {{}, {}}});
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|     auto I = NodeStore.begin();
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|     auto *Node = &*I;
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|     if (!Parent)
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|       Roots[ThreadId].push_back(Node);
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|     return Node;
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|   }
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| 
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|   StackTrieNode *findRootNode(uint32_t ThreadId, int32_t FuncId) {
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|     const auto &RootsByThread = Roots[ThreadId];
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|     auto I = find_if(RootsByThread,
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|                      [&](StackTrieNode *N) { return N->FuncId == FuncId; });
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|     return (I == RootsByThread.end()) ? nullptr : *I;
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|   }
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| 
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| public:
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|   enum class AccountRecordStatus {
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|     OK,              // Successfully processed
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|     ENTRY_NOT_FOUND, // An exit record had no matching call stack entry
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|     UNKNOWN_RECORD_TYPE
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|   };
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| 
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|   struct AccountRecordState {
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|     // We keep track of whether the call stack is currently unwinding.
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|     bool wasLastRecordExit;
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| 
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|     static AccountRecordState CreateInitialState() { return {false}; }
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|   };
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| 
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|   AccountRecordStatus accountRecord(const XRayRecord &R,
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|                                     AccountRecordState *state) {
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|     auto &TS = ThreadStackMap[R.TId];
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|     switch (R.Type) {
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|     case RecordTypes::CUSTOM_EVENT:
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|     case RecordTypes::TYPED_EVENT:
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|       return AccountRecordStatus::OK;
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|     case RecordTypes::ENTER:
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|     case RecordTypes::ENTER_ARG: {
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|       state->wasLastRecordExit = false;
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|       // When we encounter a new function entry, we want to record the TSC for
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|       // that entry, and the function id. Before doing so we check the top of
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|       // the stack to see if there are callees that already represent this
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|       // function.
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|       if (TS.empty()) {
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|         auto *Root = findRootNode(R.TId, R.FuncId);
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|         TS.emplace_back(Root ? Root : createTrieNode(R.TId, R.FuncId, nullptr),
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|                         R.TSC);
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|         return AccountRecordStatus::OK;
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|       }
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| 
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|       auto &Top = TS.back();
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|       auto I = find_if(Top.first->Callees,
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|                        [&](StackTrieNode *N) { return N->FuncId == R.FuncId; });
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|       if (I == Top.first->Callees.end()) {
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|         // We didn't find the callee in the stack trie, so we're going to
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|         // add to the stack then set up the pointers properly.
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|         auto N = createTrieNode(R.TId, R.FuncId, Top.first);
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|         Top.first->Callees.emplace_back(N);
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| 
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|         // Top may be invalidated after this statement.
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|         TS.emplace_back(N, R.TSC);
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|       } else {
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|         // We found the callee in the stack trie, so we'll use that pointer
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|         // instead, add it to the stack associated with the TSC.
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|         TS.emplace_back(*I, R.TSC);
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|       }
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|       return AccountRecordStatus::OK;
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|     }
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|     case RecordTypes::EXIT:
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|     case RecordTypes::TAIL_EXIT: {
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|       bool wasLastRecordExit = state->wasLastRecordExit;
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|       state->wasLastRecordExit = true;
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|       // The exit case is more interesting, since we want to be able to deduce
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|       // missing exit records. To do that properly, we need to look up the stack
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|       // and see whether the exit record matches any of the entry records. If it
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|       // does match, we attempt to record the durations as we pop the stack to
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|       // where we see the parent.
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|       if (TS.empty()) {
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|         // Short circuit, and say we can't find it.
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| 
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|         return AccountRecordStatus::ENTRY_NOT_FOUND;
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|       }
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| 
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|       auto FunctionEntryMatch = find_if(
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|           reverse(TS), [&](const std::pair<StackTrieNode *, uint64_t> &E) {
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|             return E.first->FuncId == R.FuncId;
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|           });
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|       auto status = AccountRecordStatus::OK;
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|       if (FunctionEntryMatch == TS.rend()) {
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|         status = AccountRecordStatus::ENTRY_NOT_FOUND;
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|       } else {
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|         // Account for offset of 1 between reverse and forward iterators. We
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|         // want the forward iterator to include the function that is exited.
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|         ++FunctionEntryMatch;
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|       }
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|       auto I = FunctionEntryMatch.base();
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|       for (auto &E : make_range(I, TS.end() - 1))
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|         E.first->ExtraData.IntermediateDurations.push_back(
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|             std::max(E.second, R.TSC) - std::min(E.second, R.TSC));
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|       auto &Deepest = TS.back();
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|       if (wasLastRecordExit)
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|         Deepest.first->ExtraData.IntermediateDurations.push_back(
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|             std::max(Deepest.second, R.TSC) - std::min(Deepest.second, R.TSC));
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|       else
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|         Deepest.first->ExtraData.TerminalDurations.push_back(
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|             std::max(Deepest.second, R.TSC) - std::min(Deepest.second, R.TSC));
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|       TS.erase(I, TS.end());
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|       return status;
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|     }
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|     }
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|     return AccountRecordStatus::UNKNOWN_RECORD_TYPE;
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|   }
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| 
 | |
|   bool isEmpty() const { return Roots.empty(); }
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| 
 | |
|   void printStack(raw_ostream &OS, const StackTrieNode *Top,
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|                   FuncIdConversionHelper &FN) {
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|     // Traverse the pointers up to the parent, noting the sums, then print
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|     // in reverse order (callers at top, callees down bottom).
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|     SmallVector<const StackTrieNode *, 8> CurrentStack;
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|     for (auto *F = Top; F != nullptr; F = F->Parent)
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|       CurrentStack.push_back(F);
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|     int Level = 0;
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|     OS << formatv("{0,-5} {1,-60} {2,+12} {3,+16}\n", "lvl", "function",
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|                   "count", "sum");
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|     for (auto *F :
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|          reverse(make_range(CurrentStack.begin() + 1, CurrentStack.end()))) {
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|       auto Sum = std::accumulate(F->ExtraData.IntermediateDurations.begin(),
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|                                  F->ExtraData.IntermediateDurations.end(), 0LL);
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|       auto FuncId = FN.SymbolOrNumber(F->FuncId);
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|       OS << formatv("#{0,-4} {1,-60} {2,+12} {3,+16}\n", Level++,
 | |
|                     FuncId.size() > 60 ? FuncId.substr(0, 57) + "..." : FuncId,
 | |
|                     F->ExtraData.IntermediateDurations.size(), Sum);
 | |
|     }
 | |
|     auto *Leaf = *CurrentStack.begin();
 | |
|     auto LeafSum =
 | |
|         std::accumulate(Leaf->ExtraData.TerminalDurations.begin(),
 | |
|                         Leaf->ExtraData.TerminalDurations.end(), 0LL);
 | |
|     auto LeafFuncId = FN.SymbolOrNumber(Leaf->FuncId);
 | |
|     OS << formatv("#{0,-4} {1,-60} {2,+12} {3,+16}\n", Level++,
 | |
|                   LeafFuncId.size() > 60 ? LeafFuncId.substr(0, 57) + "..."
 | |
|                                          : LeafFuncId,
 | |
|                   Leaf->ExtraData.TerminalDurations.size(), LeafSum);
 | |
|     OS << "\n";
 | |
|   }
 | |
| 
 | |
|   /// Prints top stacks for each thread.
 | |
|   void printPerThread(raw_ostream &OS, FuncIdConversionHelper &FN) {
 | |
|     for (auto iter : Roots) {
 | |
|       OS << "Thread " << iter.first << ":\n";
 | |
|       print(OS, FN, iter.second);
 | |
|       OS << "\n";
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   /// Prints timing sums for each stack in each threads.
 | |
|   template <AggregationType AggType>
 | |
|   void printAllPerThread(raw_ostream &OS, FuncIdConversionHelper &FN,
 | |
|                          StackOutputFormat format) {
 | |
|     for (auto iter : Roots) {
 | |
|       uint32_t threadId = iter.first;
 | |
|       RootVector &perThreadRoots = iter.second;
 | |
|       bool reportThreadId = true;
 | |
|       printAll<AggType>(OS, FN, perThreadRoots, threadId, reportThreadId);
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   /// Prints top stacks from looking at all the leaves and ignoring thread IDs.
 | |
|   /// Stacks that consist of the same function IDs but were called in different
 | |
|   /// thread IDs are not considered unique in this printout.
 | |
|   void printIgnoringThreads(raw_ostream &OS, FuncIdConversionHelper &FN) {
 | |
|     RootVector RootValues;
 | |
| 
 | |
|     // Function to pull the values out of a map iterator.
 | |
|     using RootsType = decltype(Roots.begin())::value_type;
 | |
|     auto MapValueFn = [](const RootsType &Value) { return Value.second; };
 | |
| 
 | |
|     for (const auto &RootNodeRange :
 | |
|          make_range(map_iterator(Roots.begin(), MapValueFn),
 | |
|                     map_iterator(Roots.end(), MapValueFn))) {
 | |
|       for (auto *RootNode : RootNodeRange)
 | |
|         RootValues.push_back(RootNode);
 | |
|     }
 | |
| 
 | |
|     print(OS, FN, RootValues);
 | |
|   }
 | |
| 
 | |
|   /// Creates a merged list of Tries for unique stacks that disregards their
 | |
|   /// thread IDs.
 | |
|   RootVector mergeAcrossThreads(std::forward_list<StackTrieNode> &NodeStore) {
 | |
|     RootVector MergedByThreadRoots;
 | |
|     for (auto MapIter : Roots) {
 | |
|       const auto &RootNodeVector = MapIter.second;
 | |
|       for (auto *Node : RootNodeVector) {
 | |
|         auto MaybeFoundIter =
 | |
|             find_if(MergedByThreadRoots, [Node](StackTrieNode *elem) {
 | |
|               return Node->FuncId == elem->FuncId;
 | |
|             });
 | |
|         if (MaybeFoundIter == MergedByThreadRoots.end()) {
 | |
|           MergedByThreadRoots.push_back(Node);
 | |
|         } else {
 | |
|           MergedByThreadRoots.push_back(mergeTrieNodes(
 | |
|               **MaybeFoundIter, *Node, nullptr, NodeStore, mergeStackDuration));
 | |
|           MergedByThreadRoots.erase(MaybeFoundIter);
 | |
|         }
 | |
|       }
 | |
|     }
 | |
|     return MergedByThreadRoots;
 | |
|   }
 | |
| 
 | |
|   /// Print timing sums for all stacks merged by Thread ID.
 | |
|   template <AggregationType AggType>
 | |
|   void printAllAggregatingThreads(raw_ostream &OS, FuncIdConversionHelper &FN,
 | |
|                                   StackOutputFormat format) {
 | |
|     std::forward_list<StackTrieNode> AggregatedNodeStore;
 | |
|     RootVector MergedByThreadRoots = mergeAcrossThreads(AggregatedNodeStore);
 | |
|     bool reportThreadId = false;
 | |
|     printAll<AggType>(OS, FN, MergedByThreadRoots,
 | |
|                       /*threadId*/ 0, reportThreadId);
 | |
|   }
 | |
| 
 | |
|   /// Merges the trie by thread id before printing top stacks.
 | |
|   void printAggregatingThreads(raw_ostream &OS, FuncIdConversionHelper &FN) {
 | |
|     std::forward_list<StackTrieNode> AggregatedNodeStore;
 | |
|     RootVector MergedByThreadRoots = mergeAcrossThreads(AggregatedNodeStore);
 | |
|     print(OS, FN, MergedByThreadRoots);
 | |
|   }
 | |
| 
 | |
|   // TODO: Add a format option when more than one are supported.
 | |
|   template <AggregationType AggType>
 | |
|   void printAll(raw_ostream &OS, FuncIdConversionHelper &FN,
 | |
|                 RootVector RootValues, uint32_t ThreadId, bool ReportThread) {
 | |
|     SmallVector<const StackTrieNode *, 16> S;
 | |
|     for (const auto *N : RootValues) {
 | |
|       S.clear();
 | |
|       S.push_back(N);
 | |
|       while (!S.empty()) {
 | |
|         auto *Top = S.pop_back_val();
 | |
|         printSingleStack<AggType>(OS, FN, ReportThread, ThreadId, Top);
 | |
|         for (const auto *C : Top->Callees)
 | |
|           S.push_back(C);
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   /// Prints values for stacks in a format consumable for the flamegraph.pl
 | |
|   /// tool. This is a line based format that lists each level in the stack
 | |
|   /// hierarchy in a semicolon delimited form followed by a space and a numeric
 | |
|   /// value. If breaking down by thread, the thread ID will be added as the
 | |
|   /// root level of the stack.
 | |
|   template <AggregationType AggType>
 | |
|   void printSingleStack(raw_ostream &OS, FuncIdConversionHelper &Converter,
 | |
|                         bool ReportThread, uint32_t ThreadId,
 | |
|                         const StackTrieNode *Node) {
 | |
|     if (ReportThread)
 | |
|       OS << "thread_" << ThreadId << ";";
 | |
|     SmallVector<const StackTrieNode *, 5> lineage{};
 | |
|     lineage.push_back(Node);
 | |
|     while (lineage.back()->Parent != nullptr)
 | |
|       lineage.push_back(lineage.back()->Parent);
 | |
|     while (!lineage.empty()) {
 | |
|       OS << Converter.SymbolOrNumber(lineage.back()->FuncId) << ";";
 | |
|       lineage.pop_back();
 | |
|     }
 | |
|     OS << " " << GetValueForStack<AggType>(Node) << "\n";
 | |
|   }
 | |
| 
 | |
|   void print(raw_ostream &OS, FuncIdConversionHelper &FN,
 | |
|              RootVector RootValues) {
 | |
|     // Go through each of the roots, and traverse the call stack, producing the
 | |
|     // aggregates as you go along. Remember these aggregates and stacks, and
 | |
|     // show summary statistics about:
 | |
|     //
 | |
|     //   - Total number of unique stacks
 | |
|     //   - Top 10 stacks by count
 | |
|     //   - Top 10 stacks by aggregate duration
 | |
|     SmallVector<std::pair<const StackTrieNode *, uint64_t>, 11>
 | |
|         TopStacksByCount;
 | |
|     SmallVector<std::pair<const StackTrieNode *, uint64_t>, 11> TopStacksBySum;
 | |
|     auto greater_second =
 | |
|         [](const std::pair<const StackTrieNode *, uint64_t> &A,
 | |
|            const std::pair<const StackTrieNode *, uint64_t> &B) {
 | |
|           return A.second > B.second;
 | |
|         };
 | |
|     uint64_t UniqueStacks = 0;
 | |
|     for (const auto *N : RootValues) {
 | |
|       SmallVector<const StackTrieNode *, 16> S;
 | |
|       S.emplace_back(N);
 | |
| 
 | |
|       while (!S.empty()) {
 | |
|         auto *Top = S.pop_back_val();
 | |
| 
 | |
|         // We only start printing the stack (by walking up the parent pointers)
 | |
|         // when we get to a leaf function.
 | |
|         if (!Top->ExtraData.TerminalDurations.empty()) {
 | |
|           ++UniqueStacks;
 | |
|           auto TopSum =
 | |
|               std::accumulate(Top->ExtraData.TerminalDurations.begin(),
 | |
|                               Top->ExtraData.TerminalDurations.end(), 0uLL);
 | |
|           {
 | |
|             auto E = std::make_pair(Top, TopSum);
 | |
|             TopStacksBySum.insert(
 | |
|                 llvm::lower_bound(TopStacksBySum, E, greater_second), E);
 | |
|             if (TopStacksBySum.size() == 11)
 | |
|               TopStacksBySum.pop_back();
 | |
|           }
 | |
|           {
 | |
|             auto E =
 | |
|                 std::make_pair(Top, Top->ExtraData.TerminalDurations.size());
 | |
|             TopStacksByCount.insert(std::lower_bound(TopStacksByCount.begin(),
 | |
|                                                      TopStacksByCount.end(), E,
 | |
|                                                      greater_second),
 | |
|                                     E);
 | |
|             if (TopStacksByCount.size() == 11)
 | |
|               TopStacksByCount.pop_back();
 | |
|           }
 | |
|         }
 | |
|         for (const auto *C : Top->Callees)
 | |
|           S.push_back(C);
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     // Now print the statistics in the end.
 | |
|     OS << "\n";
 | |
|     OS << "Unique Stacks: " << UniqueStacks << "\n";
 | |
|     OS << "Top 10 Stacks by leaf sum:\n\n";
 | |
|     for (const auto &P : TopStacksBySum) {
 | |
|       OS << "Sum: " << P.second << "\n";
 | |
|       printStack(OS, P.first, FN);
 | |
|     }
 | |
|     OS << "\n";
 | |
|     OS << "Top 10 Stacks by leaf count:\n\n";
 | |
|     for (const auto &P : TopStacksByCount) {
 | |
|       OS << "Count: " << P.second << "\n";
 | |
|       printStack(OS, P.first, FN);
 | |
|     }
 | |
|     OS << "\n";
 | |
|   }
 | |
| };
 | |
| 
 | |
| std::string CreateErrorMessage(StackTrie::AccountRecordStatus Error,
 | |
|                                const XRayRecord &Record,
 | |
|                                const FuncIdConversionHelper &Converter) {
 | |
|   switch (Error) {
 | |
|   case StackTrie::AccountRecordStatus::ENTRY_NOT_FOUND:
 | |
|     return std::string(
 | |
|         formatv("Found record {0} with no matching function entry\n",
 | |
|                 format_xray_record(Record, Converter)));
 | |
|   default:
 | |
|     return std::string(formatv("Unknown error type for record {0}\n",
 | |
|                                format_xray_record(Record, Converter)));
 | |
|   }
 | |
| }
 | |
| 
 | |
| static CommandRegistration Unused(&Stack, []() -> Error {
 | |
|   // Load each file provided as a command-line argument. For each one of them
 | |
|   // account to a single StackTrie, and just print the whole trie for now.
 | |
|   StackTrie ST;
 | |
|   InstrumentationMap Map;
 | |
|   if (!StacksInstrMap.empty()) {
 | |
|     auto InstrumentationMapOrError = loadInstrumentationMap(StacksInstrMap);
 | |
|     if (!InstrumentationMapOrError)
 | |
|       return joinErrors(
 | |
|           make_error<StringError>(
 | |
|               Twine("Cannot open instrumentation map: ") + StacksInstrMap,
 | |
|               std::make_error_code(std::errc::invalid_argument)),
 | |
|           InstrumentationMapOrError.takeError());
 | |
|     Map = std::move(*InstrumentationMapOrError);
 | |
|   }
 | |
| 
 | |
|   if (SeparateThreadStacks && AggregateThreads)
 | |
|     return make_error<StringError>(
 | |
|         Twine("Can't specify options for per thread reporting and reporting "
 | |
|               "that aggregates threads."),
 | |
|         std::make_error_code(std::errc::invalid_argument));
 | |
| 
 | |
|   if (!DumpAllStacks && StacksOutputFormat != HUMAN)
 | |
|     return make_error<StringError>(
 | |
|         Twine("Can't specify a non-human format without -all-stacks."),
 | |
|         std::make_error_code(std::errc::invalid_argument));
 | |
| 
 | |
|   if (DumpAllStacks && StacksOutputFormat == HUMAN)
 | |
|     return make_error<StringError>(
 | |
|         Twine("You must specify a non-human format when reporting with "
 | |
|               "-all-stacks."),
 | |
|         std::make_error_code(std::errc::invalid_argument));
 | |
| 
 | |
|   symbolize::LLVMSymbolizer Symbolizer;
 | |
|   FuncIdConversionHelper FuncIdHelper(StacksInstrMap, Symbolizer,
 | |
|                                       Map.getFunctionAddresses());
 | |
|   // TODO: Someday, support output to files instead of just directly to
 | |
|   // standard output.
 | |
|   for (const auto &Filename : StackInputs) {
 | |
|     auto TraceOrErr = loadTraceFile(Filename);
 | |
|     if (!TraceOrErr) {
 | |
|       if (!StackKeepGoing)
 | |
|         return joinErrors(
 | |
|             make_error<StringError>(
 | |
|                 Twine("Failed loading input file '") + Filename + "'",
 | |
|                 std::make_error_code(std::errc::invalid_argument)),
 | |
|             TraceOrErr.takeError());
 | |
|       logAllUnhandledErrors(TraceOrErr.takeError(), errs());
 | |
|       continue;
 | |
|     }
 | |
|     auto &T = *TraceOrErr;
 | |
|     StackTrie::AccountRecordState AccountRecordState =
 | |
|         StackTrie::AccountRecordState::CreateInitialState();
 | |
|     for (const auto &Record : T) {
 | |
|       auto error = ST.accountRecord(Record, &AccountRecordState);
 | |
|       if (error != StackTrie::AccountRecordStatus::OK) {
 | |
|         if (!StackKeepGoing)
 | |
|           return make_error<StringError>(
 | |
|               CreateErrorMessage(error, Record, FuncIdHelper),
 | |
|               make_error_code(errc::illegal_byte_sequence));
 | |
|         errs() << CreateErrorMessage(error, Record, FuncIdHelper);
 | |
|       }
 | |
|     }
 | |
|   }
 | |
|   if (ST.isEmpty()) {
 | |
|     return make_error<StringError>(
 | |
|         "No instrumented calls were accounted in the input file.",
 | |
|         make_error_code(errc::result_out_of_range));
 | |
|   }
 | |
| 
 | |
|   // Report the stacks in a long form mode for another tool to analyze.
 | |
|   if (DumpAllStacks) {
 | |
|     if (AggregateThreads) {
 | |
|       switch (RequestedAggregation) {
 | |
|       case AggregationType::TOTAL_TIME:
 | |
|         ST.printAllAggregatingThreads<AggregationType::TOTAL_TIME>(
 | |
|             outs(), FuncIdHelper, StacksOutputFormat);
 | |
|         break;
 | |
|       case AggregationType::INVOCATION_COUNT:
 | |
|         ST.printAllAggregatingThreads<AggregationType::INVOCATION_COUNT>(
 | |
|             outs(), FuncIdHelper, StacksOutputFormat);
 | |
|         break;
 | |
|       }
 | |
|     } else {
 | |
|       switch (RequestedAggregation) {
 | |
|       case AggregationType::TOTAL_TIME:
 | |
|         ST.printAllPerThread<AggregationType::TOTAL_TIME>(outs(), FuncIdHelper,
 | |
|                                                           StacksOutputFormat);
 | |
|         break;
 | |
|       case AggregationType::INVOCATION_COUNT:
 | |
|         ST.printAllPerThread<AggregationType::INVOCATION_COUNT>(
 | |
|             outs(), FuncIdHelper, StacksOutputFormat);
 | |
|         break;
 | |
|       }
 | |
|     }
 | |
|     return Error::success();
 | |
|   }
 | |
| 
 | |
|   // We're only outputting top stacks.
 | |
|   if (AggregateThreads) {
 | |
|     ST.printAggregatingThreads(outs(), FuncIdHelper);
 | |
|   } else if (SeparateThreadStacks) {
 | |
|     ST.printPerThread(outs(), FuncIdHelper);
 | |
|   } else {
 | |
|     ST.printIgnoringThreads(outs(), FuncIdHelper);
 | |
|   }
 | |
|   return Error::success();
 | |
| });
 |