[llvm-branch-commits] CodeGen: Fix implementation of __builtin_trivially_relocate. (PR #140312)

[via llvm-branch-commits]

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@@ -4425,6 +4425,14 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
     Address Dest = EmitPointerWithAlignment(E->getArg(0));
     Address Src = EmitPointerWithAlignment(E->getArg(1));
     Value *SizeVal = EmitScalarExpr(E->getArg(2));
+    if (BuiltinIDIfNoAsmLabel == Builtin::BI__builtin_trivially_relocate)
+      SizeVal = Builder.CreateMul(
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cor3ntin wrote:

I think generally, there is the question of whether we want UBSAN to enforce the preconditions of trivially_relocate (object completeness, valid ranges), However, because the intent is for that builtin to be wrapped in a standard function, it's probably better to only do the checks there, it would integrate better with hardening/contracts, and we don't (afaik) have precondition checks for builtins


https://github.com/llvm/llvm-project/pull/140312