[llvm] [Bolt] Add a new hidden option to perf2bolt for testing purpose (PR #163785)

[Paschalis Mpeis via llvm-commits]

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@@ -372,6 +379,80 @@ void DataAggregator::parsePreAggregated() {
   }
 }
 
+bool DataAggregator::isMMapEvent(StringRef Line) {
+  // Short cut to avoid string find is possible.
+  if (Line.empty() || Line.size() < 50)
+    return false;
+
+  // Check that PERF_RECORD_MMAP2 or PERF_RECORD_MMAP appear in the line.
+  return Line.contains("PERF_RECORD_MMAP");
+}
+
+void DataAggregator::parsePerfScriptEvents() {
+  outs() << "PERF2BOLT: parsing a hybrid perf-script events...\n";
+  NamedRegionTimer T("parsePerfScriptEvents", "Parsing perf-script events",
+                     TimerGroupName, TimerGroupDesc, opts::TimeAggregator);
+
+  ErrorOr<std::unique_ptr<MemoryBuffer>> MB =
+      MemoryBuffer::getFileOrSTDIN(Filename);
+  if (std::error_code EC = MB.getError()) {
+    errs() << "PERF2BOLT-ERROR: cannot open " << Filename << ": "
+           << EC.message() << "\n";
+    exit(1);
+  }
+
+  FileBuf = std::move(*MB);
+  ParsingBuf = FileBuf->getBuffer();
+  Col = 0;
+  Line = 1;
+  std::string MMapEvents = "";
+  std::string BranchEvents = "";
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paschalis-mpeis wrote:

Based on my point [(1) here](https://github.com/llvm/llvm-project/pull/163785#pullrequestreview-3428929110), I was wondering too, if we can reuse most of the prior logic. Somehow cleanly 'hijack' parsePerfData/prepareToParse to keep the parsing flow (ie, attempt to parse mmap, task, branch/basic-samples, mem events) while feeding from textual input instead of an actual 'perf script' process.

https://github.com/llvm/llvm-project/pull/163785