[llvm] [llvm-readobj][COFF] Implement --coff-pseudoreloc in llvm-readobj to dump runtime pseudo-relocation records (PR #151816)

[Martin Storsjö via llvm-commits]

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@@ -2000,6 +2001,122 @@ void COFFDumper::printCOFFBaseReloc() {
   }
 }
 
+void COFFDumper::printCOFFPseudoReloc() {
+  const StringRef RelocBeginName = Obj->getArch() == Triple::x86
+                                       ? "___RUNTIME_PSEUDO_RELOC_LIST__"
+                                       : "__RUNTIME_PSEUDO_RELOC_LIST__";
+  const StringRef RelocEndName = Obj->getArch() == Triple::x86
+                                     ? "___RUNTIME_PSEUDO_RELOC_LIST_END__"
+                                     : "__RUNTIME_PSEUDO_RELOC_LIST_END__";
+
+  COFFSymbolRef RelocBegin, RelocEnd;
+  auto Count = Obj->getNumberOfSymbols();
+  if (Count == 0) {
+    W.startLine() << "The symbol table has been stripped\n";
+    return;
+  }
+  for (auto i = 0u;
+       i < Count && (!RelocBegin.getRawPtr() || !RelocEnd.getRawPtr()); ++i) {
+    auto Sym = Obj->getSymbol(i);
+    if (Sym.takeError())
+      continue;
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mstorsjo wrote:

IIRC you can't just ignore the errors like this (the error classes has got a destructor that aborts if you haven't actually done anything with the error). See other similar functions here for ways of doing it; e.g. `if (!Sym) { consumeError(Sym.takeError()); return; }` if we just want to ignore the error, or `if (!Sym) reportError(Sym.takeError(), Obj->getFileName());` if we want to print it.

These error classes are quite tricky to use in that sense, so ideally one would need to have tested triggering all of these error cases - and unfortunately it can probably be quite hard to actually force these to fail as well... Perhaps by hex editing a binary to make symbol string offsets out of bounds?

https://github.com/llvm/llvm-project/pull/151816