[llvm-branch-commits] [llvm] [DLCov] Origin-Tracking: Add debugify support (PR #143594)

[Jeremy Morse via llvm-branch-commits]

================
@@ -59,6 +65,52 @@ cl::opt<Level> DebugifyLevel(
 
 raw_ostream &dbg() { return Quiet ? nulls() : errs(); }
 
+#if LLVM_ENABLE_DEBUGLOC_TRACKING_ORIGIN
+// These maps refer to addresses in this instance of LLVM, so we can reuse them
+// everywhere - therefore, we store them at file scope.
+static SymbolizedAddressMap SymbolizedAddrs;
+static AddressSet UnsymbolizedAddrs;
+
+std::string symbolizeStackTrace(const Instruction *I) {
+  // We flush the set of unsymbolized addresses at the latest possible moment,
+  // i.e. now.
+  if (!UnsymbolizedAddrs.empty()) {
+    sys::symbolizeAddresses(UnsymbolizedAddrs, SymbolizedAddrs);
+    UnsymbolizedAddrs.clear();
+  }
+  auto OriginStackTraces = I->getDebugLoc().getOriginStackTraces();
+  std::string Result;
+  raw_string_ostream OS(Result);
+  for (size_t TraceIdx = 0; TraceIdx < OriginStackTraces.size(); ++TraceIdx) {
+    if (TraceIdx != 0)
+      OS << "========================================\n";
+    auto &[Depth, StackTrace] = OriginStackTraces[TraceIdx];
+    unsigned VirtualFrameNo = 0;
+    for (int Frame = 0; Frame < Depth; ++Frame) {
+      assert(SymbolizedAddrs.contains(StackTrace[Frame]) &&
+             "Expected each address to have been symbolized.");
+      for (std::string &SymbolizedFrame : SymbolizedAddrs[StackTrace[Frame]]) {
+        OS << right_justify(formatv("#{0}", VirtualFrameNo++).str(), std::log10(Depth) + 2)
+          << ' ' << SymbolizedFrame << '\n';
+      }
+    }
+  }
+  return Result;
+}
+void collectStackAddresses(Instruction &I) {
+  auto &OriginStackTraces = I.getDebugLoc().getOriginStackTraces();
----------------
jmorse wrote:

Major nit; would we be able to name the type here rather than `auto`? It'll make the resulting code a lot easier to localise and dissect for future readers. (The next `auto` makes sense of course).

https://github.com/llvm/llvm-project/pull/143594