[llvm] Gsymutil aggregation similar to DwarfDump --verify (PR #81154)

[Greg Clayton via llvm-commits]

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@@ -0,0 +1,107 @@
+//===- DwarfTransformer.h ---------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_GSYM_OUTPUTAGGREGATOR_H
+#define LLVM_DEBUGINFO_GSYM_OUTPUTAGGREGATOR_H
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/DebugInfo/GSYM/ExtractRanges.h"
+
+#include <map>
+#include <string>
+
+namespace llvm {
+
+class raw_ostream;
+
+namespace gsym {
+
+class OutputAggregator {
+protected:
+  // A std::map is preferable over an llvm::StringMap for presenting results
+  // in a predictable order.
+  std::map<std::string, unsigned> Aggregation;
+  raw_ostream *Out;
+  bool IncludeDetail;
+
+public:
+  OutputAggregator(raw_ostream *out, bool includeDetail = true)
+      : Out(out), IncludeDetail(includeDetail) {}
+
+  // Do I want a "detail level" thing? I think so, actually...
+  void ShowDetail(bool showDetail) { IncludeDetail = showDetail; }
+  bool IsShowingDetail() const { return IncludeDetail; }
+
+  size_t GetNumCategories() const { return Aggregation.size(); }
+
+  void Report(StringRef s, std::function<void(raw_ostream &o)> detailCallback) {
+    Aggregation[std::string(s)]++;
+    if (IncludeDetail && Out != nullptr)
+      detailCallback(*Out);
+  }
+
+  void Report(StringRef s, std::function<void()> detailCallback) {
+    Aggregation[std::string(s)]++;
+    if (IncludeDetail)
+      detailCallback();
+  }
+
+  void EnumerateResults(
+      std::function<void(StringRef, unsigned)> handleCounts) const {
+    for (auto &&[name, count] : Aggregation) {
+      handleCounts(name, count);
+    }
+  }
+
+  raw_ostream *GetOS() const { return Out; }
+
+  // You can just use the stream, and if it's null, nothing happens.
+  // Don't do a lot of stuff like this, but it's convenient for silly stuff.
+  // It doesn't work with things that have custom insertion operators, though.
+  template <typename T> OutputAggregator &operator<<(T &&value) {
+    if (Out != nullptr)
+      *Out << value;
+    return *this;
+  }
+
+  // For multi-threaded usage, we can collect stuff in another aggregator,
+  // then merge it in here
+  void Merge(const OutputAggregator &other) {
+    for (auto &&[name, count] : other.Aggregation) {
+      auto it = Aggregation.find(name);
+      if (it == Aggregation.end())
+        Aggregation.emplace(name, count);
+      else
+        it->second += count;
+    }
+  }
+};
+
+class StringAggregator : public OutputAggregator {
----------------
clayborg wrote:

You are using this class and adding a `bool includeDetail` into the `OutputAggregator` construcor, but we can probably get rid of this class and the `bool includeDetail` from `OutputAggregator` if we just rely on the output stream being NULL. More details in the threading in the `DWARFTransformer.cpp` file where this class was being used.

https://github.com/llvm/llvm-project/pull/81154