[compiler-rt] [flang] [libcxx] [llvm] [lldb] [clang] [mlir] [lld] [clang] Fix unexpected `-Wconstant-logical-operand` in C23 (PR #80724)

[Mariya Podchishchaeva via cfe-commits]

https://github.com/Fznamznon updated https://github.com/llvm/llvm-project/pull/80724

>From dd81e1aa3de2c38be91140b57d2c277a56e899bf Mon Sep 17 00:00:00 2001
From: "Podchishchaeva, Mariya" <mariya.podchishchaeva at intel.com>
Date: Mon, 5 Feb 2024 10:43:56 -0800
Subject: [PATCH 1/2] [clang] Fix unexpected `-Wconstant-logical-operand` in
 C23

C23 has bool, but logical operators still return int. Double check that
we're not in C23 to avoid false-positive -Wconstant-logical-operand.

Fixes https://github.com/llvm/llvm-project/issues/64356
---
 clang/lib/Sema/SemaExpr.cpp                |  3 ++-
 clang/test/Sema/warn-int-in-bool-context.c | 11 +++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index d15278bce5a6ba..f65b3abe5eaa24 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -14073,7 +14073,8 @@ inline QualType Sema::CheckLogicalOperands(ExprResult &LHS, ExprResult &RHS,
     Expr::EvalResult EVResult;
     if (RHS.get()->EvaluateAsInt(EVResult, Context)) {
       llvm::APSInt Result = EVResult.Val.getInt();
-      if ((getLangOpts().Bool && !RHS.get()->getType()->isBooleanType() &&
+      if ((getLangOpts().Bool && !getLangOpts().C23 &&
+           !RHS.get()->getType()->isBooleanType() &&
            !RHS.get()->getExprLoc().isMacroID()) ||
           (Result != 0 && Result != 1)) {
         Diag(Loc, diag::warn_logical_instead_of_bitwise)
diff --git a/clang/test/Sema/warn-int-in-bool-context.c b/clang/test/Sema/warn-int-in-bool-context.c
index a6890161b5af89..c111a5af23f577 100644
--- a/clang/test/Sema/warn-int-in-bool-context.c
+++ b/clang/test/Sema/warn-int-in-bool-context.c
@@ -79,3 +79,14 @@ int test(int a, unsigned b, enum num n) {
   // Don't warn in macros.
   return SHIFT(1, a);
 }
+
+int GH64356(int arg) {
+  if ((arg == 1) && (1 == 1)) return 1;
+    return 0;
+
+  if ((64 > 32) && (32 < 64))
+    return 2;
+
+  if ((1 == 1) && (arg == 1)) return 1;
+    return 0;
+}

>From 980e24e8c08c3d5a3b25cda69e329c3c0329dd25 Mon Sep 17 00:00:00 2001
From: "Podchishchaeva, Mariya" <mariya.podchishchaeva at intel.com>
Date: Tue, 6 Feb 2024 02:03:59 -0800
Subject: [PATCH 2/2] Check another lang option, add a release note

---
 clang/docs/ReleaseNotes.rst | 4 ++++
 clang/lib/Sema/SemaExpr.cpp | 3 +--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 4d57ea4fd55b8c..802c44b6c86080 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -164,6 +164,10 @@ Bug Fixes in This Version
 - Clang now accepts qualified partial/explicit specializations of variable templates that
   are not nominable in the lookup context of the specialization.
 
+- Clang now doesn't produce false-positive warning `-Wconstant-logical-operand`
+  for logical operators in C23.
+  Fixes (`#64356 <https://github.com/llvm/llvm-project/issues/64356>`_).
+
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index f65b3abe5eaa24..4049ab3bf6cafb 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -14073,8 +14073,7 @@ inline QualType Sema::CheckLogicalOperands(ExprResult &LHS, ExprResult &RHS,
     Expr::EvalResult EVResult;
     if (RHS.get()->EvaluateAsInt(EVResult, Context)) {
       llvm::APSInt Result = EVResult.Val.getInt();
-      if ((getLangOpts().Bool && !getLangOpts().C23 &&
-           !RHS.get()->getType()->isBooleanType() &&
+      if ((getLangOpts().CPlusPlus && !RHS.get()->getType()->isBooleanType() &&
            !RHS.get()->getExprLoc().isMacroID()) ||
           (Result != 0 && Result != 1)) {
         Diag(Loc, diag::warn_logical_instead_of_bitwise)