diff options
| -rw-r--r-- | lib/CodeGen/CGExprScalar.cpp | 13 | ||||
| -rw-r--r-- | test/CodeGen/vla.c | 9 |
2 files changed, 20 insertions, 2 deletions
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp index 73e94d1ece..055e3f7e67 100644 --- a/lib/CodeGen/CGExprScalar.cpp +++ b/lib/CodeGen/CGExprScalar.cpp @@ -209,8 +209,17 @@ public: } Value *VisitCastExpr(CastExpr *E) { // Make sure to evaluate VLA bounds now so that we have them for later. - if (E->getType()->isVariablyModifiedType()) - CGF.EmitVLASize(E->getType()); + if (E->getType()->isVariablyModifiedType()) { + // Implicit cast of a null pointer to a vla type need not result in vla + // size computation which is not always possible in any case (see pr7827). + bool NeedSize = true; + if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) + NeedSize = + !ICE->getSubExpr()->isNullPointerConstant(CGF.getContext(), + Expr::NPC_ValueDependentIsNull); + if (NeedSize) + CGF.EmitVLASize(E->getType()); + } return EmitCastExpr(E); } diff --git a/test/CodeGen/vla.c b/test/CodeGen/vla.c index 17704727b0..8011497bf5 100644 --- a/test/CodeGen/vla.c +++ b/test/CodeGen/vla.c @@ -50,3 +50,12 @@ void f_8403108(unsigned x) { } // CHECK: call void @llvm.stackrestore(i8* } + +// pr7827 +void function(short width, int data[][width]) {} + +void test() { + // CHECK: call void @function(i16 signext 1, i32* null) + function(1, 0); +} + |