[clang] 18e7bcb - [clang][Interp] Reject inc/dec ops before C++ 14

[Timm Bäder via cfe-commits]

Author: Timm Bäder
Date: 2024-05-21T13:20:42+02:00
New Revision: 18e7bcbae12bc2e2cf9888844a0b3f12075f508c

URL: https://github.com/llvm/llvm-project/commit/18e7bcbae12bc2e2cf9888844a0b3f12075f508c
DIFF: https://github.com/llvm/llvm-project/commit/18e7bcbae12bc2e2cf9888844a0b3f12075f508c.diff

LOG: [clang][Interp] Reject inc/dec ops before C++ 14

Added: 
    

Modified: 
    clang/lib/AST/Interp/ByteCodeExprGen.cpp
    clang/test/AST/Interp/cxx11.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Interp/ByteCodeExprGen.cpp b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
index 33d69d04487de..859a3fabea32b 100644
--- a/clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -3395,6 +3395,9 @@ bool ByteCodeExprGen<Emitter>::VisitUnaryOperator(const UnaryOperator *E) {
 
   switch (E->getOpcode()) {
   case UO_PostInc: { // x++
+    if (!Ctx.getLangOpts().CPlusPlus14)
+      return this->emitInvalid(E);
+
     if (!this->visit(SubExpr))
       return false;
 
@@ -3413,6 +3416,9 @@ bool ByteCodeExprGen<Emitter>::VisitUnaryOperator(const UnaryOperator *E) {
     return DiscardResult ? this->emitIncPop(*T, E) : this->emitInc(*T, E);
   }
   case UO_PostDec: { // x--
+    if (!Ctx.getLangOpts().CPlusPlus14)
+      return this->emitInvalid(E);
+
     if (!this->visit(SubExpr))
       return false;
 
@@ -3431,6 +3437,9 @@ bool ByteCodeExprGen<Emitter>::VisitUnaryOperator(const UnaryOperator *E) {
     return DiscardResult ? this->emitDecPop(*T, E) : this->emitDec(*T, E);
   }
   case UO_PreInc: { // ++x
+    if (!Ctx.getLangOpts().CPlusPlus14)
+      return this->emitInvalid(E);
+
     if (!this->visit(SubExpr))
       return false;
 
@@ -3475,6 +3484,9 @@ bool ByteCodeExprGen<Emitter>::VisitUnaryOperator(const UnaryOperator *E) {
     return E->isGLValue() || this->emitLoadPop(*T, E);
   }
   case UO_PreDec: { // --x
+    if (!Ctx.getLangOpts().CPlusPlus14)
+      return this->emitInvalid(E);
+
     if (!this->visit(SubExpr))
       return false;
 

diff  --git a/clang/test/AST/Interp/cxx11.cpp b/clang/test/AST/Interp/cxx11.cpp
index 993e3618a3784..f06a5dd173cba 100644
--- a/clang/test/AST/Interp/cxx11.cpp
+++ b/clang/test/AST/Interp/cxx11.cpp
@@ -30,3 +30,19 @@ constexpr S s = { 5 };
 constexpr const int *p = &s.m + 1;
 
 constexpr const int *np2 = &(*(int(*)[4])nullptr)[0]; // ok
+
+constexpr int preDec(int x) { // both-error {{never produces a constant expression}}
+  return --x;                 // both-note {{subexpression}}
+}
+
+constexpr int postDec(int x) { // both-error {{never produces a constant expression}}
+  return x--;                  // both-note {{subexpression}}
+}
+
+constexpr int preInc(int x) { // both-error {{never produces a constant expression}}
+  return ++x;                  // both-note {{subexpression}}
+}
+
+constexpr int postInc(int x) { // both-error {{never produces a constant expression}}
+  return x++;                  // both-note {{subexpression}}
+}