[llvm] [TableGen] Detect invalid -D arguments and fail. (PR #102813)

[Rahul Joshi via llvm-commits]

================
@@ -54,9 +74,17 @@ TGLexer::TGLexer(SourceMgr &SM, ArrayRef<std::string> Macros) : SrcMgr(SM) {
   PrepIncludeStack.push_back(
       std::make_unique<std::vector<PreprocessorControlDesc>>());
 
-  // Put all macros defined in the command line into the DefinedMacros set.
-  for (const std::string &MacroName : Macros)
+  // Add all macros defined on the command line to the DefinedMacros set.
+  // Check invalid macro names and print fatal error if we find one.
+  for (const std::string &MacroName : Macros) {
+    const char *Begin = MacroName.c_str();
+    const char *End = lexMacroName(Begin);
----------------
jurahul wrote:

Thanks, that's good to know. With the change to use a StringRef, we don't need to worry about it now.

https://github.com/llvm/llvm-project/pull/102813