From f675ec6165ab6add5e57cd43a2e9fa1a9bc21d81 Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic@gmail.com>
Date: Tue, 21 Mar 2023 12:58:57 +0900
Subject: [PATCH] TableGen: Make 2nd arg `MainFn` of `TableGenMain(argv0,
 MainFn)` optional.

---
 llvm/include/llvm/TableGen/Main.h | 5 ++++-
 llvm/lib/TableGen/Main.cpp        | 9 +++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/llvm/include/llvm/TableGen/Main.h b/llvm/include/llvm/TableGen/Main.h
index 4e05da3..4639ec7 100644
--- a/llvm/include/llvm/TableGen/Main.h
+++ b/llvm/include/llvm/TableGen/Main.h
@@ -13,6 +13,8 @@
 #ifndef LLVM_TABLEGEN_MAIN_H
 #define LLVM_TABLEGEN_MAIN_H
 
+#include <functional>
+
 namespace llvm {
 
 class raw_ostream;
@@ -22,7 +24,8 @@ class RecordKeeper;
 /// Returns true on error, false otherwise.
 using TableGenMainFn = bool (raw_ostream &OS, RecordKeeper &Records);
 
-int TableGenMain(const char *argv0, TableGenMainFn *MainFn);
+int TableGenMain(const char *argv0,
+                 std::function<TableGenMainFn> MainFn = nullptr);
 
 } // end namespace llvm
 
diff --git a/llvm/lib/TableGen/Main.cpp b/llvm/lib/TableGen/Main.cpp
index 2f9ac86..ee72b4b 100644
--- a/llvm/lib/TableGen/Main.cpp
+++ b/llvm/lib/TableGen/Main.cpp
@@ -95,7 +95,8 @@ static int createDependencyFile(const TGParser &Parser, const char *argv0) {
   return 0;
 }
 
-int llvm::TableGenMain(const char *argv0, TableGenMainFn *MainFn) {
+int llvm::TableGenMain(const char *argv0,
+                       std::function<TableGenMainFn> MainFn) {
   RecordKeeper Records;
 
   if (TimePhases)
@@ -129,7 +130,11 @@ int llvm::TableGenMain(const char *argv0, TableGenMainFn *MainFn) {
   Records.startBackendTimer("Backend overall");
   std::string OutString;
   raw_string_ostream Out(OutString);
-  unsigned status = MainFn(Out, Records);
+  unsigned status = 0;
+  if (MainFn)
+    status = MainFn(Out, Records);
+  else
+    return 1;
   Records.stopBackendTimer();
   if (status)
     return 1;
-- 
2.7.4