[llvm] [Object] Parsing and dumping of SFrame FDEs (PR #149828)

[James Henderson via llvm-commits]

================
@@ -6433,6 +6436,86 @@ template <typename ELFT> void ELFDumper<ELFT>::printMemtag() {
   printMemtag(DynamicEntries, AndroidNoteDesc, GlobalDescriptors);
 }
 
+template <typename ELFT>
+void ELFDumper<ELFT>::printSFrameHeader(
+    const SFrameParser<ELFT::Endianness> &Parser) {
+  DictScope HeaderScope(W, "Header");
+
+  const sframe::Preamble<ELFT::Endianness> &Preamble = Parser.getPreamble();
+  W.printHex("Magic", Preamble.Magic.value());
+  W.printEnum("Version", Preamble.Version.value(), sframe::getVersions());
+  W.printFlags("Flags", Preamble.Flags.value(), sframe::getFlags());
+
+  const sframe::Header<ELFT::Endianness> &Header = Parser.getHeader();
+  W.printEnum("ABI", Header.ABIArch.value(), sframe::getABIs());
+
+  W.printNumber(("CFA fixed FP offset" +
+                 Twine(Parser.usesFixedFPOffset() ? "" : " (unused)"))
+                    .str(),
+                Header.CFAFixedFPOffset.value());
+
+  W.printNumber(("CFA fixed RA offset" +
+                 Twine(Parser.usesFixedRAOffset() ? "" : " (unused)"))
+                    .str(),
+                Header.CFAFixedRAOffset.value());
+
+  W.printNumber("Auxiliary header length", Header.AuxHdrLen.value());
+  W.printNumber("Num FDEs", Header.NumFDEs.value());
+  W.printNumber("Num FREs", Header.NumFREs.value());
+  W.printNumber("FRE subsection length", Header.FRELen.value());
+  W.printNumber("FDE subsection offset", Header.FDEOff.value());
+  W.printNumber("FRE subsection offset", Header.FREOff.value());
+
+  if (Expected<ArrayRef<uint8_t>> Aux = Parser.getAuxHeader())
+    W.printHexList("Auxiliary header", *Aux);
+  else
+    reportWarning(Aux.takeError(), FileName);
+}
+
+template <typename ELFT>
+void ELFDumper<ELFT>::printSFrameFDEs(
+    const SFrameParser<ELFT::Endianness> &Parser) {
+  typename SFrameParser<ELFT::Endianness>::FDERange FDEs;
+  if (Error Err = Parser.fdes().moveInto(FDEs)) {
+    reportWarning(std::move(Err), FileName);
+    return;
+  }
+
+  ListScope IndexScope(W, "Function Index");
+  for (auto It = FDEs.begin(); It != FDEs.end(); ++It) {
+    DictScope FDEScope(
+        W,
+        formatv("FuncDescEntry [{0}]", std::distance(FDEs.begin(), It)).str());
+
+    W.printHex("PC", Parser.getAbsoluteStartAddress(It));
+    W.printHex("Size", It->Size);
+    W.printHex("Start FRE Offset", It->StartFREOff);
+    W.printNumber("Num FREs", It->NumFREs);
+
+    W.printHex("Info", It->Info);
+    W.printEnum("FRE Type", It->getFREType(), sframe::getFRETypes());
+    W.printEnum("FDE Type", It->getFDEType(), sframe::getFDETypes());
+    switch (Parser.getHeader().ABIArch) {
+    case sframe::ABI::AArch64EndianBig:
+    case sframe::ABI::AArch64EndianLittle:
+      W.printEnum("PAuth Key", sframe::AArch64PAuthKey(It->getPAuthKey()),
+                  sframe::getAArch64PAuthKeys());
+      break;
+    default:
+      W.printNumber("PAuth Key (unused)", It->getPAuthKey());
+      break;
+    }
----------------
jh7370 wrote:

I found it a touch confusing looking at the code seeing "Info" split into its component parts and also listed itself. Perhaps that suggests this should be a nested scope, with the individual parts of Info each listed in the scope, possibly with the combined value? Alternatively, is the raw info value actually useful? (I could imagine it might be, but would like a justification)

https://github.com/llvm/llvm-project/pull/149828