[lld] [ELF] Added `struct Token` and changed `next()` and `peek()` to return Token (PR #100180)

[via llvm-commits]

================
@@ -1554,61 +1595,66 @@ Expr ScriptParser::readPrimary() {
       return llvm::Log2_64_Ceil(std::max(a().getValue(), UINT64_C(1)));
     };
   }
-  if (tok == "MAX" || tok == "MIN") {
+  case Tok::Max:
+  case Tok::Min: {
     expect("(");
     Expr a = readExpr();
     expect(",");
     Expr b = readExpr();
     expect(")");
-    if (tok == "MIN")
+    if (tok.kind == Tok::Min)
       return [=] { return std::min(a().getValue(), b().getValue()); };
     return [=] { return std::max(a().getValue(), b().getValue()); };
   }
-  if (tok == "ORIGIN") {
+  case Tok::Origin: {
     StringRef name = readParenLiteral();
     if (script->memoryRegions.count(name) == 0) {
       setError("memory region not defined: " + name);
       return [] { return 0; };
     }
     return script->memoryRegions[name]->origin;
   }
-  if (tok == "SEGMENT_START") {
+  case Tok::SegmentStart: {
     expect("(");
     skip();
     expect(",");
     Expr e = readExpr();
     expect(")");
     return [=] { return e(); };
   }
-  if (tok == "SIZEOF") {
+  case Tok::Sizeof: {
     StringRef name = unquote(readParenLiteral());
     OutputSection *cmd = &script->getOrCreateOutputSection(name)->osec;
     // Linker script does not create an output section if its content is empty.
     // We want to allow SIZEOF(.foo) where .foo is a section which happened to
     // be empty.
     return [=] { return cmd->size; };
   }
-  if (tok == "SIZEOF_HEADERS")
+  case Tok::SizeofHeaders:
     return [=] { return elf::getHeaderSize(); };
 
-  // Tok is the dot.
-  if (tok == ".")
-    return [=] { return script->getSymbolValue(tok, location); };
-
-  // Tok is a literal number.
-  if (std::optional<uint64_t> val = parseInt(tok))
-    return [=] { return *val; };
-
-  // Tok is a symbol name.
-  if (tok.starts_with("\""))
-    tok = unquote(tok);
-  else if (!isValidSymbolName(tok))
-    setError("malformed number: " + tok);
-  if (activeProvideSym)
-    script->provideMap[*activeProvideSym].push_back(tok);
-  else
-    script->referencedSymbols.push_back(tok);
-  return [=] { return script->getSymbolValue(tok, location); };
+  default: {
+    // Tok is the dot.
+    if (tok == ".")
+      return [=] { return script->getSymbolValue(tok.val, location); };
+
+    // Tok is a literal number.
+    if (std::optional<uint64_t> val = parseInt(tok.val))
+      return [=] { return *val; };
+
+    // Tok is a symbol name.
+    StringRef tokVal = tok.val;
+    if (tokVal.starts_with("\""))
----------------
PiJoules wrote:

nit: `tokVal.starts_with('"')`

https://github.com/llvm/llvm-project/pull/100180