[clang][Interp] PointerToBoolean casts

Just emit e != nullptr for these.

Differential Revision: https://reviews.llvm.org/D148981

diff --git a/clang/lib/AST/Interp/ByteCodeExprGen.cpp b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
index e28532b..536438b 100644 (file)
--- a/clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -150,6 +150,17 @@ bool ByteCodeExprGen<Emitter>::VisitCastExpr(const CastExpr *CE) {
     return this->emitCast(*FromT, *ToT, CE);
   }
 
+  case CK_PointerToBoolean: {
+    // Just emit p != nullptr for this.
+    if (!this->visit(SubExpr))
+      return false;
+
+    if (!this->emitNullPtr(CE))
+      return false;
+
+    return this->emitNEPtr(CE);
+  }
+
   case CK_ToVoid:
     return discard(SubExpr);
 

diff --git a/clang/test/AST/Interp/literals.cpp b/clang/test/AST/Interp/literals.cpp
index f31a490..54f3aef 100644 (file)
--- a/clang/test/AST/Interp/literals.cpp
+++ b/clang/test/AST/Interp/literals.cpp
@@ -101,6 +101,19 @@ constexpr int gimme(int k) {
 }
 static_assert(gimme(5) == 5, "");
 
+namespace PointerToBool {
+
+  constexpr void *N = nullptr;
+  constexpr bool B = N;
+  static_assert(!B, "");
+  static_assert(!N, "");
+
+  constexpr float F = 1.0;
+  constexpr const float *FP = &F;
+  static_assert(FP, "");
+  static_assert(!!FP, "");
+}
+
 namespace SizeOf {
   constexpr int soint = sizeof(int);
   constexpr int souint = sizeof(unsigned int);