[llvm] [CGData] Declare command line options in TableGen, one struct per library (PR #226087)

[Alexis Engelke via llvm-commits]

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@@ -1593,6 +1638,24 @@ bool CommandLineParser::ParseCommandLineOptions(
         Handler = LookupLongOption(SubCommand::getTopLevel(), ArgName, Value,
                                    LongOptionsUseDoubleDash, HaveDoubleDash);
 
+      if (!Handler && (!LongOptionsUseDoubleDash || HaveDoubleDash)) {
+        if (LibraryOptions *L = lookupLibraryOption(ArgName.split('=').first)) {
+          // An option takes at most one separate value.
+          StringSaver Saver(LibraryArgAlloc);
+          const char *Args[2];
+          unsigned NumArgs = std::min(argc - i, 2);
+          for (unsigned J = 0; J != NumArgs; ++J)
+            Args[J] = Saver.save(argv[i + J]).data();
+          unsigned N = 1;
+          if (Error E = L->parse(ArrayRef(Args, NumArgs), N)) {
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aengelke wrote:

We probably want to reuse the BumpPtrAllocator for storing argument lists in the future (and might not want to duplicate all argument strings, many arguments are integers/bools for which this is unnecessary). We can fix this later, but I expect that this interface will need changes.

https://github.com/llvm/llvm-project/pull/226087