[clang] [clang][Sema] Avoid warnings when mixing diagnostic categories (NFC) (PR #159316)

[Bruno De Fraine via cfe-commits]

https://github.com/brunodf-snps created https://github.com/llvm/llvm-project/pull/159316

These statements conditionally select between diagnostics of different categories (common vs. sema). Although the diagnostic IDs do not overlap between categories, they are organized in different enums, and this raises warnings in specific compilers. The clang warning suggest this behavior is deprecated in C++20 (the warning is ignored by default in C++17 mode). By converting the diagnostic IDs to unsigned, we avoid the issue.

>From c7d2fc33c5eeddae72312753588ec5e657e20150 Mon Sep 17 00:00:00 2001
From: Bruno De Fraine <brunodf at synopsys.com>
Date: Wed, 17 Sep 2025 12:12:27 +0200
Subject: [PATCH] [clang][Sema] Avoid warnings when mixing diagnostic
 categories (NFC)

These statements conditionally select between diagnostics of different
categories (common vs. sema). Although the diagnostic IDs do not overlap
between categories, they are organized in different enums, and this
raises warnings in specific compilers. The clang warning suggest this
behavior is deprecated in C++20. By converting the diagnostic IDs to
unsigned, we avoid the issue.
---
 clang/lib/Sema/SemaDeclAttr.cpp | 7 ++++---
 clang/lib/Sema/SemaStmtAttr.cpp | 7 ++++---
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 44906456f3371..12f06070a3db2 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -6836,9 +6836,10 @@ ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D, const ParsedAttr &AL,
   if (AL.getKind() == ParsedAttr::UnknownAttribute ||
       !AL.existsInTarget(S.Context.getTargetInfo())) {
     if (AL.isRegularKeywordAttribute() || AL.isDeclspecAttribute()) {
-      S.Diag(AL.getLoc(), AL.isRegularKeywordAttribute()
-                              ? diag::err_keyword_not_supported_on_target
-                              : diag::warn_unhandled_ms_attribute_ignored)
+      S.Diag(AL.getLoc(),
+             AL.isRegularKeywordAttribute()
+                 ? (unsigned)diag::err_keyword_not_supported_on_target
+                 : (unsigned)diag::warn_unhandled_ms_attribute_ignored)
           << AL.getAttrName() << AL.getRange();
     } else {
       S.DiagnoseUnknownAttribute(AL);
diff --git a/clang/lib/Sema/SemaStmtAttr.cpp b/clang/lib/Sema/SemaStmtAttr.cpp
index 77aa7164d4555..66785c7deee57 100644
--- a/clang/lib/Sema/SemaStmtAttr.cpp
+++ b/clang/lib/Sema/SemaStmtAttr.cpp
@@ -673,9 +673,10 @@ static Attr *ProcessStmtAttribute(Sema &S, Stmt *St, const ParsedAttr &A,
         (S.Context.getLangOpts().SYCLIsDevice && Aux &&
          A.existsInTarget(*Aux)))) {
     if (A.isRegularKeywordAttribute() || A.isDeclspecAttribute()) {
-      S.Diag(A.getLoc(), A.isRegularKeywordAttribute()
-                             ? diag::err_keyword_not_supported_on_target
-                             : diag::warn_unhandled_ms_attribute_ignored)
+      S.Diag(A.getLoc(),
+             A.isRegularKeywordAttribute()
+                 ? (unsigned)diag::err_keyword_not_supported_on_target
+                 : (unsigned)diag::warn_unhandled_ms_attribute_ignored)
           << A << A.getRange();
     } else {
       S.DiagnoseUnknownAttribute(A);