Add an API to let ClangD work here.

Author: chandlerc

clang-tools-extra/clangd/CompileCommands.cpp

@@ -458,20 +458,6 @@ llvm::ArrayRef<ArgStripper::Rule> ArgStripper::rulesFor(llvm::StringRef Arg) {
       PrevAlias[Self] = T;
       NextAlias[T] = Self;
     };
-    // Also grab prefixes for each option, these are not fully exposed.
-    llvm::ArrayRef<llvm::StringLiteral> Prefixes[DriverID::LastOption];
-
-#define PREFIX(NAME, VALUE)                                                    \
-  static constexpr llvm::StringLiteral NAME##_init[] = VALUE;                  \
-  static constexpr llvm::ArrayRef<llvm::StringLiteral> NAME(                   \
-      NAME##_init, std::size(NAME##_init) - 1);
-#define OPTION(PREFIX, PREFIXED_NAME, ID, KIND, GROUP, ALIAS, ALIASARGS,       \
-               FLAGS, VISIBILITY, PARAM, HELPTEXT, HELPTEXTSFORVARIANTS,       \
-               METAVAR, VALUES)                                                \
-  Prefixes[DriverID::OPT_##ID] = PREFIX;
-#include "clang/Driver/Options.inc"
-#undef OPTION
-#undef PREFIX
 
     struct {
       DriverID ID;
@@ -498,7 +484,9 @@ llvm::ArrayRef<ArgStripper::Rule> ArgStripper::rulesFor(llvm::StringRef Arg) {
       llvm::SmallVector<Rule> Rules;
       // Iterate over each alias, to add rules for parsing it.
       for (unsigned A = ID; A != DriverID::OPT_INVALID; A = NextAlias[A]) {
-        if (!Prefixes[A].size()) // option groups.
+        llvm::SmallVector<llvm::StringRef, 4> Prefixes;
+        DriverTable.appendOptionPrefixes(A, Prefixes);
+        if (Prefixes.empty()) // option groups.
           continue;
         auto Opt = DriverTable.getOption(A);
         // Exclude - and -foo pseudo-options.
@@ -507,7 +495,7 @@ llvm::ArrayRef<ArgStripper::Rule> ArgStripper::rulesFor(llvm::StringRef Arg) {
         auto Modes = getModes(Opt);
         std::pair<unsigned, unsigned> ArgCount = getArgCount(Opt);
         // Iterate over each spelling of the alias, e.g. -foo vs --foo.
-        for (StringRef Prefix : Prefixes[A]) {
+        for (StringRef Prefix : Prefixes) {
           llvm::SmallString<64> Buf(Prefix);
           Buf.append(Opt.getName());
           llvm::StringRef Spelling = Result->try_emplace(Buf).first->getKey();

llvm/include/llvm/Option/OptTable.h

@@ -197,6 +197,12 @@ class OptTable {
                            : I.getPrefix(StrTable, PrefixesTable, 0);
   }
 
+  void appendOptionPrefixes(OptSpecifier id,
+                            SmallVectorImpl<StringRef> &Prefixes) const {
+    const Info &I = getInfo(id);
+    I.appendPrefixes(StrTable, PrefixesTable, Prefixes);
+  }
+
   /// Lookup the prefixed name of the given option.
   StringRef getOptionPrefixedName(OptSpecifier id) const {
     return getInfo(id).getPrefixedName(StrTable);