__builtin_object_size refinements. WIP.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@85136 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 94d2299..9129558 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -873,6 +873,36 @@
switch (E->isBuiltinCall(Info.Ctx)) {
default:
return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E);
+
+ case Builtin::BI__builtin_object_size: {
+ llvm::APSInt Result(32);
+
+ if (!E->getArg(1)->isIntegerConstantExpr(Result, Info.Ctx))
+ assert(0 && "arg2 not ice in __builtin_object_size");
+
+ const Expr *Arg = E->getArg(0)->IgnoreParens();
+ Expr::EvalResult Base;
+ if (Arg->Evaluate(Base, Info.Ctx)
+ && Base.Val.getKind() == APValue::LValue
+ && !Base.HasSideEffects)
+ if (const Expr *LVBase = Base.Val.getLValueBase())
+ if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(LVBase)) {
+ if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
+ uint64_t Size = Info.Ctx.getTypeSize(VD->getType()) / 8;
+ Size -= Base.Val.getLValueOffset();
+ return Success(Size, E);
+ }
+ }
+
+ if (Base.HasSideEffects) {
+ if (Result.getSExtValue() < 2)
+ return Success(-1, E);
+ return Success(0, E);
+ }
+
+ return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E);
+ }
+
case Builtin::BI__builtin_classify_type:
return Success(EvaluateBuiltinClassifyType(E), E);