diff --git a/clang/include/clang/AST/OpenMPClause.h b/clang/include/clang/AST/OpenMPClause.h
index 72effbc3e02fc..1118d3e062e68 100644
--- a/clang/include/clang/AST/OpenMPClause.h
+++ b/clang/include/clang/AST/OpenMPClause.h
@@ -1865,43 +1865,62 @@ class OMPSeverityClause final : public OMPClause {
 /// \endcode
 /// In this example directive '#pragma omp error' has simple
 /// 'message' clause with user error message of "GNU compiler required.".
-class OMPMessageClause final
-    : public OMPOneStmtClause<llvm::omp::OMPC_message, OMPClause>,
-      public OMPClauseWithPreInit {
+class OMPMessageClause final : public OMPClause {
   friend class OMPClauseReader;
 
+  /// Location of '('
+  SourceLocation LParenLoc;
+
+  // Expression of the 'message' clause.
+  Stmt *MessageString = nullptr;
+
   /// Set message string of the clause.
-  void setMessageString(Expr *MS) { setStmt(MS); }
+  void setMessageString(Expr *MS) { MessageString = MS; }
+
+  /// Sets the location of '('.
+  void setLParenLoc(SourceLocation Loc) { LParenLoc = Loc; }
 
 public:
   /// Build 'message' clause with message string argument
   ///
   /// \param MS Argument of the clause (message string).
-  /// \param HelperMS Helper statement for the construct.
-  /// \param CaptureRegion Innermost OpenMP region where expressions in this
-  /// clause must be captured.
   /// \param StartLoc Starting location of the clause.
   /// \param LParenLoc Location of '('.
   /// \param EndLoc Ending location of the clause.
-  OMPMessageClause(Expr *MS, Stmt *HelperMS, OpenMPDirectiveKind CaptureRegion,
-                   SourceLocation StartLoc, SourceLocation LParenLoc,
+  OMPMessageClause(Expr *MS, SourceLocation StartLoc, SourceLocation LParenLoc,
                    SourceLocation EndLoc)
-      : OMPOneStmtClause(MS, StartLoc, LParenLoc, EndLoc),
-        OMPClauseWithPreInit(this) {
-    setPreInitStmt(HelperMS, CaptureRegion);
-  }
+      : OMPClause(llvm::omp::OMPC_message, StartLoc, EndLoc),
+        LParenLoc(LParenLoc), MessageString(MS) {}
 
   /// Build an empty clause.
-  OMPMessageClause() : OMPOneStmtClause(), OMPClauseWithPreInit(this) {}
+  OMPMessageClause()
+      : OMPClause(llvm::omp::OMPC_message, SourceLocation(), SourceLocation()) {
+  }
+
+  /// Returns the locaiton of '('.
+  SourceLocation getLParenLoc() const { return LParenLoc; }
 
   /// Returns message string of the clause.
-  Expr *getMessageString() const { return getStmtAs<Expr>(); }
+  Expr *getMessageString() const { return cast_or_null<Expr>(MessageString); }
+
+  child_range children() {
+    return child_range(&MessageString, &MessageString + 1);
+  }
+
+  const_child_range children() const {
+    return const_child_range(&MessageString, &MessageString + 1);
+  }
+
+  child_range used_children() {
+    return child_range(child_iterator(), child_iterator());
+  }
+
+  const_child_range used_children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
 
-  /// Try to evaluate the message string at compile time.
-  std::optional<std::string> tryEvaluateString(ASTContext &Ctx) const {
-    if (Expr *MessageExpr = getMessageString())
-      return MessageExpr->tryEvaluateString(Ctx);
-    return std::nullopt;
+  static bool classof(const OMPClause *T) {
+    return T->getClauseKind() == llvm::omp::OMPC_message;
   }
 };
 
diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td b/clang/include/clang/Basic/DiagnosticParseKinds.td
index d1a60490b6517..3a6a9e582c7ca 100644
--- a/clang/include/clang/Basic/DiagnosticParseKinds.td
+++ b/clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -1506,10 +1506,8 @@ def err_omp_unexpected_directive : Error<
   "unexpected OpenMP directive %select{|'#pragma omp %1'}0">;
 def err_omp_expected_punc : Error<
   "expected ',' or ')' in '%0' %select{clause|directive}1">;
-def warn_clause_expected_string_literal : Warning<
+def warn_clause_expected_string : Warning<
   "expected string literal in 'clause %0' - ignoring">, InGroup<IgnoredPragmas>;
-def warn_clause_expected_string: Warning<
-  "expected string in 'clause %0' - ignoring">, InGroup<IgnoredPragmas>;
 def err_omp_unexpected_clause : Error<
   "unexpected OpenMP clause '%0' in directive '#pragma omp %1'">;
 def err_omp_unexpected_clause_extension_only : Error<
diff --git a/clang/lib/AST/OpenMPClause.cpp b/clang/lib/AST/OpenMPClause.cpp
index 0930ca27c29f8..588b0dcc6d7b8 100644
--- a/clang/lib/AST/OpenMPClause.cpp
+++ b/clang/lib/AST/OpenMPClause.cpp
@@ -104,8 +104,6 @@ const OMPClauseWithPreInit *OMPClauseWithPreInit::get(const OMPClause *C) {
     return static_cast<const OMPFilterClause *>(C);
   case OMPC_ompx_dyn_cgroup_mem:
     return static_cast<const OMPXDynCGroupMemClause *>(C);
-  case OMPC_message:
-    return static_cast<const OMPMessageClause *>(C);
   case OMPC_default:
   case OMPC_proc_bind:
   case OMPC_safelen:
@@ -160,6 +158,7 @@ const OMPClauseWithPreInit *OMPClauseWithPreInit::get(const OMPClause *C) {
   case OMPC_self_maps:
   case OMPC_at:
   case OMPC_severity:
+  case OMPC_message:
   case OMPC_device_type:
   case OMPC_match:
   case OMPC_nontemporal:
@@ -1964,10 +1963,8 @@ void OMPClausePrinter::VisitOMPSeverityClause(OMPSeverityClause *Node) {
 }
 
 void OMPClausePrinter::VisitOMPMessageClause(OMPMessageClause *Node) {
-  OS << "message(";
-  if (Expr *E = Node->getMessageString())
-    E->printPretty(OS, nullptr, Policy);
-  OS << ")";
+  OS << "message(\""
+     << cast<StringLiteral>(Node->getMessageString())->getString() << "\")";
 }
 
 void OMPClausePrinter::VisitOMPScheduleClause(OMPScheduleClause *Node) {
diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index b38eb54036e60..b66608319bb51 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -1845,11 +1845,11 @@ void CGOpenMPRuntime::emitIfClause(CodeGenFunction &CGF, const Expr *Cond,
   CGF.EmitBlock(ContBlock, /*IsFinished=*/true);
 }
 
-void CGOpenMPRuntime::emitParallelCall(
-    CodeGenFunction &CGF, SourceLocation Loc, llvm::Function *OutlinedFn,
-    ArrayRef<llvm::Value *> CapturedVars, const Expr *IfCond,
-    llvm::Value *NumThreads, OpenMPNumThreadsClauseModifier NumThreadsModifier,
-    OpenMPSeverityClauseKind Severity, const Expr *Message) {
+void CGOpenMPRuntime::emitParallelCall(CodeGenFunction &CGF, SourceLocation Loc,
+                                       llvm::Function *OutlinedFn,
+                                       ArrayRef<llvm::Value *> CapturedVars,
+                                       const Expr *IfCond,
+                                       llvm::Value *NumThreads) {
   if (!CGF.HaveInsertPoint())
     return;
   llvm::Value *RTLoc = emitUpdateLocation(CGF, Loc);
@@ -2372,8 +2372,9 @@ void CGOpenMPRuntime::emitBarrierCall(CodeGenFunction &CGF, SourceLocation Loc,
 
 void CGOpenMPRuntime::emitErrorCall(CodeGenFunction &CGF, SourceLocation Loc,
                                     Expr *ME, bool IsFatal) {
-  llvm::Value *MVL = ME ? CGF.EmitScalarExpr(ME)
-                        : llvm::ConstantPointerNull::get(CGF.VoidPtrTy);
+  llvm::Value *MVL =
+      ME ? CGF.EmitStringLiteralLValue(cast<StringLiteral>(ME)).getPointer(CGF)
+         : llvm::ConstantPointerNull::get(CGF.VoidPtrTy);
   // Build call void __kmpc_error(ident_t *loc, int severity, const char
   // *message)
   llvm::Value *Args[] = {
@@ -2698,54 +2699,18 @@ llvm::Value *CGOpenMPRuntime::emitForNext(CodeGenFunction &CGF,
       CGF.getContext().BoolTy, Loc);
 }
 
-llvm::Value *CGOpenMPRuntime::emitMessageClause(CodeGenFunction &CGF,
-                                                const Expr *Message) {
-  if (!Message)
-    return llvm::ConstantPointerNull::get(CGF.VoidPtrTy);
-  return CGF.EmitScalarExpr(Message);
-}
-
-llvm::Value *
-CGOpenMPRuntime::emitMessageClause(CodeGenFunction &CGF,
-                                   const OMPMessageClause *MessageClause) {
-  return emitMessageClause(
-      CGF, MessageClause ? MessageClause->getMessageString() : nullptr);
-}
-
-llvm::Value *
-CGOpenMPRuntime::emitSeverityClause(OpenMPSeverityClauseKind Severity) {
-  // OpenMP 6.0, 10.4: "If no severity clause is specified then the effect is
-  // as if sev-level is fatal."
-  return llvm::ConstantInt::get(CGM.Int32Ty,
-                                Severity == OMPC_SEVERITY_warning ? 1 : 2);
-}
-
-llvm::Value *
-CGOpenMPRuntime::emitSeverityClause(const OMPSeverityClause *SeverityClause) {
-  return emitSeverityClause(SeverityClause ? SeverityClause->getSeverityKind()
-                                           : OMPC_SEVERITY_unknown);
-}
-
-void CGOpenMPRuntime::emitNumThreadsClause(
-    CodeGenFunction &CGF, llvm::Value *NumThreads, SourceLocation Loc,
-    OpenMPNumThreadsClauseModifier Modifier, OpenMPSeverityClauseKind Severity,
-    const Expr *Message) {
+void CGOpenMPRuntime::emitNumThreadsClause(CodeGenFunction &CGF,
+                                           llvm::Value *NumThreads,
+                                           SourceLocation Loc) {
   if (!CGF.HaveInsertPoint())
     return;
-  llvm::SmallVector<llvm::Value *, 4> Args(
-      {emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc),
-       CGF.Builder.CreateIntCast(NumThreads, CGF.Int32Ty, /*isSigned*/ true)});
   // Build call __kmpc_push_num_threads(&loc, global_tid, num_threads)
-  // or __kmpc_push_num_threads_strict(&loc, global_tid, num_threads, severity,
-  // messsage) if strict modifier is used.
-  RuntimeFunction FnID = OMPRTL___kmpc_push_num_threads;
-  if (Modifier == OMPC_NUMTHREADS_strict) {
-    FnID = OMPRTL___kmpc_push_num_threads_strict;
-    Args.push_back(emitSeverityClause(Severity));
-    Args.push_back(emitMessageClause(CGF, Message));
-  }
-  CGF.EmitRuntimeCall(
-      OMPBuilder.getOrCreateRuntimeFunction(CGM.getModule(), FnID), Args);
+  llvm::Value *Args[] = {
+      emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc),
+      CGF.Builder.CreateIntCast(NumThreads, CGF.Int32Ty, /*isSigned*/ true)};
+  CGF.EmitRuntimeCall(OMPBuilder.getOrCreateRuntimeFunction(
+                          CGM.getModule(), OMPRTL___kmpc_push_num_threads),
+                      Args);
 }
 
 void CGOpenMPRuntime::emitProcBindClause(CodeGenFunction &CGF,
@@ -12149,11 +12114,12 @@ llvm::Function *CGOpenMPSIMDRuntime::emitTaskOutlinedFunction(
   llvm_unreachable("Not supported in SIMD-only mode");
 }
 
-void CGOpenMPSIMDRuntime::emitParallelCall(
-    CodeGenFunction &CGF, SourceLocation Loc, llvm::Function *OutlinedFn,
-    ArrayRef<llvm::Value *> CapturedVars, const Expr *IfCond,
-    llvm::Value *NumThreads, OpenMPNumThreadsClauseModifier NumThreadsModifier,
-    OpenMPSeverityClauseKind Severity, const Expr *Message) {
+void CGOpenMPSIMDRuntime::emitParallelCall(CodeGenFunction &CGF,
+                                           SourceLocation Loc,
+                                           llvm::Function *OutlinedFn,
+                                           ArrayRef<llvm::Value *> CapturedVars,
+                                           const Expr *IfCond,
+                                           llvm::Value *NumThreads) {
   llvm_unreachable("Not supported in SIMD-only mode");
 }
 
@@ -12256,10 +12222,9 @@ llvm::Value *CGOpenMPSIMDRuntime::emitForNext(CodeGenFunction &CGF,
   llvm_unreachable("Not supported in SIMD-only mode");
 }
 
-void CGOpenMPSIMDRuntime::emitNumThreadsClause(
-    CodeGenFunction &CGF, llvm::Value *NumThreads, SourceLocation Loc,
-    OpenMPNumThreadsClauseModifier Modifier, OpenMPSeverityClauseKind Severity,
-    const Expr *Message) {
+void CGOpenMPSIMDRuntime::emitNumThreadsClause(CodeGenFunction &CGF,
+                                               llvm::Value *NumThreads,
+                                               SourceLocation Loc) {
   llvm_unreachable("Not supported in SIMD-only mode");
 }
 
diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.h b/clang/lib/CodeGen/CGOpenMPRuntime.h
index eb04eceee236c..5be48b439f4fd 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.h
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.h
@@ -777,22 +777,11 @@ class CGOpenMPRuntime {
   /// specified, nullptr otherwise.
   /// \param NumThreads The value corresponding to the num_threads clause, if
   /// any, or nullptr.
-  /// \param NumThreadsModifier The modifier of the num_threads clause, if
-  /// any, ignored otherwise.
-  /// \param Severity The severity corresponding to the num_threads clause, if
-  /// any, ignored otherwise.
-  /// \param Message The message string corresponding to the num_threads clause,
-  /// if any, or nullptr.
   ///
-  virtual void
-  emitParallelCall(CodeGenFunction &CGF, SourceLocation Loc,
-                   llvm::Function *OutlinedFn,
-                   ArrayRef<llvm::Value *> CapturedVars, const Expr *IfCond,
-                   llvm::Value *NumThreads,
-                   OpenMPNumThreadsClauseModifier NumThreadsModifier =
-                       OMPC_NUMTHREADS_unknown,
-                   OpenMPSeverityClauseKind Severity = OMPC_SEVERITY_fatal,
-                   const Expr *Message = nullptr);
+  virtual void emitParallelCall(CodeGenFunction &CGF, SourceLocation Loc,
+                                llvm::Function *OutlinedFn,
+                                ArrayRef<llvm::Value *> CapturedVars,
+                                const Expr *IfCond, llvm::Value *NumThreads);
 
   /// Emits a critical region.
   /// \param CriticalName Name of the critical region.
@@ -1048,28 +1037,13 @@ class CGOpenMPRuntime {
                                    Address IL, Address LB,
                                    Address UB, Address ST);
 
-  virtual llvm::Value *emitMessageClause(CodeGenFunction &CGF,
-                                         const Expr *Message);
-  virtual llvm::Value *emitMessageClause(CodeGenFunction &CGF,
-                                         const OMPMessageClause *MessageClause);
-
-  virtual llvm::Value *emitSeverityClause(OpenMPSeverityClauseKind Severity);
-  virtual llvm::Value *
-  emitSeverityClause(const OMPSeverityClause *SeverityClause);
-
   /// Emits call to void __kmpc_push_num_threads(ident_t *loc, kmp_int32
   /// global_tid, kmp_int32 num_threads) to generate code for 'num_threads'
   /// clause.
-  /// If the modifier 'strict' is given:
-  /// Emits call to void __kmpc_push_num_threads_strict(ident_t *loc, kmp_int32
-  /// global_tid, kmp_int32 num_threads, int severity, const char *message) to
-  /// generate code for 'num_threads' clause with 'strict' modifier.
   /// \param NumThreads An integer value of threads.
-  virtual void emitNumThreadsClause(
-      CodeGenFunction &CGF, llvm::Value *NumThreads, SourceLocation Loc,
-      OpenMPNumThreadsClauseModifier Modifier = OMPC_NUMTHREADS_unknown,
-      OpenMPSeverityClauseKind Severity = OMPC_SEVERITY_fatal,
-      const Expr *Message = nullptr);
+  virtual void emitNumThreadsClause(CodeGenFunction &CGF,
+                                    llvm::Value *NumThreads,
+                                    SourceLocation Loc);
 
   /// Emit call to void __kmpc_push_proc_bind(ident_t *loc, kmp_int32
   /// global_tid, int proc_bind) to generate code for 'proc_bind' clause.
@@ -1763,21 +1737,11 @@ class CGOpenMPSIMDRuntime final : public CGOpenMPRuntime {
   /// specified, nullptr otherwise.
   /// \param NumThreads The value corresponding to the num_threads clause, if
   /// any, or nullptr.
-  /// \param NumThreadsModifier The modifier of the num_threads clause, if
-  /// any, ignored otherwise.
-  /// \param Severity The severity corresponding to the num_threads clause, if
-  /// any, ignored otherwise.
-  /// \param Message The message string corresponding to the num_threads clause,
-  /// if any, or nullptr.
   ///
   void emitParallelCall(CodeGenFunction &CGF, SourceLocation Loc,
                         llvm::Function *OutlinedFn,
                         ArrayRef<llvm::Value *> CapturedVars,
-                        const Expr *IfCond, llvm::Value *NumThreads,
-                        OpenMPNumThreadsClauseModifier NumThreadsModifier =
-                            OMPC_NUMTHREADS_unknown,
-                        OpenMPSeverityClauseKind Severity = OMPC_SEVERITY_fatal,
-                        const Expr *Message = nullptr) override;
+                        const Expr *IfCond, llvm::Value *NumThreads) override;
 
   /// Emits a critical region.
   /// \param CriticalName Name of the critical region.
@@ -1947,16 +1911,9 @@ class CGOpenMPSIMDRuntime final : public CGOpenMPRuntime {
   /// Emits call to void __kmpc_push_num_threads(ident_t *loc, kmp_int32
   /// global_tid, kmp_int32 num_threads) to generate code for 'num_threads'
   /// clause.
-  /// If the modifier 'strict' is given:
-  /// Emits call to void __kmpc_push_num_threads_strict(ident_t *loc, kmp_int32
-  /// global_tid, kmp_int32 num_threads, int severity, const char *message) to
-  /// generate code for 'num_threads' clause with 'strict' modifier.
   /// \param NumThreads An integer value of threads.
-  void emitNumThreadsClause(
-      CodeGenFunction &CGF, llvm::Value *NumThreads, SourceLocation Loc,
-      OpenMPNumThreadsClauseModifier Modifier = OMPC_NUMTHREADS_unknown,
-      OpenMPSeverityClauseKind Severity = OMPC_SEVERITY_fatal,
-      const Expr *Message = nullptr) override;
+  void emitNumThreadsClause(CodeGenFunction &CGF, llvm::Value *NumThreads,
+                            SourceLocation Loc) override;
 
   /// Emit call to void __kmpc_push_proc_bind(ident_t *loc, kmp_int32
   /// global_tid, int proc_bind) to generate code for 'proc_bind' clause.
diff --git a/clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp b/clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp
index a80d9fd68ef2f..cff1071dd1c2e 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntimeGPU.cpp
@@ -899,10 +899,9 @@ void CGOpenMPRuntimeGPU::emitProcBindClause(CodeGenFunction &CGF,
   // Nothing to do.
 }
 
-void CGOpenMPRuntimeGPU::emitNumThreadsClause(
-    CodeGenFunction &CGF, llvm::Value *NumThreads, SourceLocation Loc,
-    OpenMPNumThreadsClauseModifier Modifier, OpenMPSeverityClauseKind Severity,
-    const Expr *Message) {
+void CGOpenMPRuntimeGPU::emitNumThreadsClause(CodeGenFunction &CGF,
+                                                llvm::Value *NumThreads,
+                                                SourceLocation Loc) {
   // Nothing to do.
 }
 
@@ -1202,17 +1201,18 @@ void CGOpenMPRuntimeGPU::emitTeamsCall(CodeGenFunction &CGF,
   emitOutlinedFunctionCall(CGF, Loc, OutlinedFn, OutlinedFnArgs);
 }
 
-void CGOpenMPRuntimeGPU::emitParallelCall(
-    CodeGenFunction &CGF, SourceLocation Loc, llvm::Function *OutlinedFn,
-    ArrayRef<llvm::Value *> CapturedVars, const Expr *IfCond,
-    llvm::Value *NumThreads, OpenMPNumThreadsClauseModifier NumThreadsModifier,
-    OpenMPSeverityClauseKind Severity, const Expr *Message) {
+void CGOpenMPRuntimeGPU::emitParallelCall(CodeGenFunction &CGF,
+                                          SourceLocation Loc,
+                                          llvm::Function *OutlinedFn,
+                                          ArrayRef<llvm::Value *> CapturedVars,
+                                          const Expr *IfCond,
+                                          llvm::Value *NumThreads) {
   if (!CGF.HaveInsertPoint())
     return;
 
-  auto &&ParallelGen = [this, Loc, OutlinedFn, CapturedVars, IfCond, NumThreads,
-                        NumThreadsModifier, Severity, Message](
-                           CodeGenFunction &CGF, PrePostActionTy &Action) {
+  auto &&ParallelGen = [this, Loc, OutlinedFn, CapturedVars, IfCond,
+                        NumThreads](CodeGenFunction &CGF,
+                                    PrePostActionTy &Action) {
     CGBuilderTy &Bld = CGF.Builder;
     llvm::Value *NumThreadsVal = NumThreads;
     llvm::Function *WFn = WrapperFunctionsMap[OutlinedFn];
@@ -1260,22 +1260,21 @@ void CGOpenMPRuntimeGPU::emitParallelCall(
       NumThreadsVal = Bld.CreateZExtOrTrunc(NumThreadsVal, CGF.Int32Ty);
 
     assert(IfCondVal && "Expected a value");
-    RuntimeFunction FnID = OMPRTL___kmpc_parallel_51;
     llvm::Value *RTLoc = emitUpdateLocation(CGF, Loc);
-    llvm::SmallVector<llvm::Value *, 10> Args(
-        {RTLoc, getThreadID(CGF, Loc), IfCondVal, NumThreadsVal,
-         llvm::ConstantInt::get(CGF.Int32Ty, -1), FnPtr, ID,
-         Bld.CreateBitOrPointerCast(CapturedVarsAd...
[truncated]