[llvm] [llvm-objcopy][COFF] Update WinCFGuard section contents after stripping (PR #153322)

[Evgenii Kudriashov via llvm-commits]

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@@ -93,59 +94,75 @@ Error COFFWriter::finalizeSymbolContents() {
   return Error::success();
 }
 
-Error COFFWriter::finalizeCFGuardContents() {
+Error COFFWriter::finalizeSymIdxContents() {
+  // CFGuards shouldn't be present in PE
+  if (Obj.IsPE)
+    return Error::success();
+
+  // Currently handle only sections consisting only of .symidx.
+  // TODO: other sections such as .impcall and .hybmp$x require more complex
+  // handling as they have more complex layout.
+  auto IsSymIdxSection = [](StringRef Name) {
+    return Name == ".gljmp$y" || Name == ".giats$y" || Name == ".gfids$y" ||
+           Name == ".gehcont$y";
+  };
+
   DenseMap<size_t, size_t> SymIdMap;
+  SmallDenseMap<ssize_t, coff_aux_section_definition *, 4> SecIdMap;
   bool NeedUpdate = false;
-  for (Symbol &Sym : Obj.getMutableSymbols()) {
+  for (auto &Sym : Obj.getMutableSymbols()) {
     NeedUpdate |= Sym.OriginalRawIndex == Sym.RawIndex;
     SymIdMap[Sym.OriginalRawIndex] = Sym.RawIndex;
+
+    // We collect only definition symbols of the sections to update checksum
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e-kud wrote:

Fixed all the full stops.

https://github.com/llvm/llvm-project/pull/153322