no method matching argtype(::CLUnexposed, ::Int64)

[IanButterworth]

I'm trying to wrap libpng (self-contained jll-based wrap code here) and I'm hitting:

ERROR: LoadError: MethodError: no method matching argtype(::CLUnexposed, ::Int64)
Closest candidates are:
  argtype(::Union{CLFunctionNoProto, CLFunctionProto}, ::Integer) at /Users/ian/.julia/packages/Clang/CiPzM/src/type.jl:137
Stacktrace:
 [1] (::Clang.var"#25#27"{CLUnexposed})(::Int64) at ./none:0
 [2] iterate at ./generator.jl:47 [inlined]
 [3] collect(::Base.Generator{UnitRange{Int64},Clang.var"#25#27"{CLUnexposed}}) at ./array.jl:620
 [4] wrap!(::DefaultContext, ::CLFunctionDecl) at /Users/ian/.julia/packages/Clang/CiPzM/src/wrap_c.jl:22
 [5] run(::WrapContext, ::Bool) at /Users/ian/.julia/packages/Clang/CiPzM/src/compat.jl:122
 [6] run(::WrapContext) at /Users/ian/.julia/packages/Clang/CiPzM/src/compat.jl:89
 [7] top-level scope at /Users/ian/.julia/dev/ImageIO/gen/libpng/wrap_libpng.jl:25

[Gnimuc]

only functions have argument types. that error basically means libclang failed to directly recognize the function prototype, so a CLUnexposed cursor was returned. More subroutines need to be added to extract the function prototype from the CLUnexposed cursor. Could you share the link to the libpng header?

[IanButterworth]

I won’t be able to share the headers until tomorrow, but the wrap script installs the jll, then links to the headers in the artifact, so that should work in 1.3+

I’ll add the headers as references tomorrow though 👍🏻

[IanButterworth]

I've added the headers for reference (they get pulled out of the jll by the wrap code): https://github.com/ianshmean/ImageIO.jl/tree/master/gen/libpng/ref_headers

[ihnorton]

FWIW, you might want to look at https://github.com/FugroRoames/LibPNG.jl (looks like they started with generated output and then customized by hand).