use sizeof(::String) instead of length(::String) for conversion to Ml…

…irStringRef

otherwise, we can't use 🍕 as a string attribute.

src/MLIR.jl

@@ -33,7 +33,7 @@ Base.cconvert(::Type{API.MlirStringRef}, s::AbstractString) =
 # Directly create `MlirStringRef` instead of adding an extra ccall.
 function Base.unsafe_convert(::Type{API.MlirStringRef}, s::Union{Symbol, String, AbstractVector{UInt8}})
     p = Base.unsafe_convert(Ptr{Cchar}, s)
-    return API.MlirStringRef(p, length(s))
+    return API.MlirStringRef(p, sizeof(s))
 end
 
 module IR

test/runtests.jl

@@ -3,3 +3,12 @@ using Test
 
 include("examples.jl")
 include("executionengine.jl")
+
+@testset "MlirStringRef conversion" begin
+    s = "mlir 😄 α γ 🍕"
+
+    ms = Base.unsafe_convert(MLIR.API.MlirStringRef, s)
+    reconstructed = unsafe_string(Ptr{Cchar}(ms.data), ms.length)
+
+    @test s == reconstructed
+end