[Clang][Interp] Diagnose use sizeless vector type as the argument of __builtin_vectorelements

Signed-off-by: yronglin <[email protected]>

Author: yronglin

clang/lib/AST/Interp/Compiler.cpp

@@ -1698,10 +1698,8 @@ bool Compiler<Emitter>::VisitUnaryExprOrTypeTraitExpr(
   if (Kind == UETT_VectorElements) {
     if (const auto *VT = E->getTypeOfArgument()->getAs<VectorType>())
       return this->emitConst(VT->getNumElements(), E);
-
-    // FIXME: Apparently we need to catch the fact that a sizeless vector type
-    // has been passed and diagnose that (at run time).
-    assert(E->getTypeOfArgument()->isSizelessVectorType());
+    if (E->getTypeOfArgument()->isSizelessVectorType())
+      return this->emitSizelessVectorElementSize(E);
   }
 
   if (Kind == UETT_VecStep) {

clang/lib/AST/Interp/Interp.h

@@ -29,6 +29,7 @@
 #include "State.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Expr.h"
+#include "clang/Basic/DiagnosticSema.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/APSInt.h"
 #include <type_traits>
@@ -2735,6 +2736,13 @@ inline bool InvalidDeclRef(InterpState &S, CodePtr OpPC,
   return CheckDeclRef(S, OpPC, DR);
 }
 
+inline bool SizelessVectorElementSize(InterpState &S, CodePtr OpPC) {
+  const SourceRange &ArgRange = S.Current->getRange(OpPC);
+  const Expr *E = S.Current->getExpr(OpPC);
+  S.FFDiag(E, diag::note_constexpr_non_const_vectorelements) << ArgRange;
+  return false;
+}
+
 inline bool Assume(InterpState &S, CodePtr OpPC) {
   const auto Val = S.Stk.pop<Boolean>();
 

clang/lib/AST/Interp/Opcodes.td

@@ -733,6 +733,8 @@ def InvalidDeclRef : Opcode {
   let Args = [ArgDeclRef];
 }
 
+def SizelessVectorElementSize : Opcode;
+
 def Assume : Opcode;
 
 def ArrayDecay : Opcode;

clang/test/SemaCXX/builtin_vectorelements.cpp

@@ -2,6 +2,7 @@
 
 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64 -target-feature +sve -std=c++20 -fsyntax-only -verify -disable-llvm-passes %s
+// RUN: %clang_cc1 -triple aarch64 -target-feature +sve -std=c++20 -fsyntax-only -verify -disable-llvm-passes -fexperimental-new-constant-interpreter %s
 
 template <typename T>
 using VecT __attribute__((vector_size(16))) = T;