[llvm] [TableGen] Avoid deprecated-enum-enum-conversion C++20 warnings; NFC (PR #218909)

[Sven van Haastregt via llvm-commits]

https://github.com/svenvh created https://github.com/llvm/llvm-project/pull/218909

The bitwise OR of different enum types resulted in many C++20 deprecation warnings in the generated option tables:

     warning: bitwise operation between different enumeration types
     ‘llvm::opt::DriverVisibility’ and
     ‘clang::options::ClangVisibility’ is deprecated
     [-Wdeprecated-enum-enum-conversion]

Fix by emitting casts to `unsigned`, matching the types of the corresponding fields in `OptTable::Info`.

>From efe59766193df85bfa52b9756a83ac829d6969b3 Mon Sep 17 00:00:00 2001
From: Sven van Haastregt <sven.vanhaastregt at arm.com>
Date: Tue, 25 Aug 2026 14:59:40 +0100
Subject: [PATCH] [TableGen] Avoid deprecated-enum-enum-conversion C++20
 warnings; NFC
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The bitwise OR of different enum types resulted in many C++20
deprecation warnings in the generated option tables:

     warning: bitwise operation between different enumeration types
     ‘llvm::opt::DriverVisibility’ and
     ‘clang::options::ClangVisibility’ is deprecated
     [-Wdeprecated-enum-enum-conversion]

Fix by emitting casts to `unsigned`, matching the types of the
corresponding fields in `OptTable::Info`.
---
 llvm/utils/TableGen/OptionParserEmitter.cpp | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/llvm/utils/TableGen/OptionParserEmitter.cpp b/llvm/utils/TableGen/OptionParserEmitter.cpp
index 829c202b495e4..471119edccfd6 100644
--- a/llvm/utils/TableGen/OptionParserEmitter.cpp
+++ b/llvm/utils/TableGen/OptionParserEmitter.cpp
@@ -524,11 +524,12 @@ static void emitOptionParser(const RecordKeeper &Records, raw_ostream &OS) {
     int NumFlags = 0;
     const ListInit *LI = R.getValueAsListInit("Flags");
     for (const Init *I : *LI)
-      OS << (NumFlags++ ? " | " : "") << cast<DefInit>(I)->getDef()->getName();
+      OS << (NumFlags++ ? " | " : "") << "static_cast<unsigned>("
+         << cast<DefInit>(I)->getDef()->getName() << ")";
     if (GroupFlags) {
       for (const Init *I : *GroupFlags)
-        OS << (NumFlags++ ? " | " : "")
-           << cast<DefInit>(I)->getDef()->getName();
+        OS << (NumFlags++ ? " | " : "") << "static_cast<unsigned>("
+           << cast<DefInit>(I)->getDef()->getName() << ")";
     }
     if (NumFlags == 0)
       OS << '0';
@@ -538,12 +539,12 @@ static void emitOptionParser(const RecordKeeper &Records, raw_ostream &OS) {
     int NumVisFlags = 0;
     LI = R.getValueAsListInit("Visibility");
     for (const Init *I : *LI)
-      OS << (NumVisFlags++ ? " | " : "")
-         << cast<DefInit>(I)->getDef()->getName();
+      OS << (NumVisFlags++ ? " | " : "") << "static_cast<unsigned>("
+         << cast<DefInit>(I)->getDef()->getName() << ")";
     if (GroupVis) {
       for (const Init *I : *GroupVis)
-        OS << (NumVisFlags++ ? " | " : "")
-           << cast<DefInit>(I)->getDef()->getName();
+        OS << (NumVisFlags++ ? " | " : "") << "static_cast<unsigned>("
+           << cast<DefInit>(I)->getDef()->getName() << ")";
     }
     if (NumVisFlags == 0)
       OS << '0';