Skip certain definitions

[lenianiva]

Is it possible to specify a list of symbols that should be ignored when generating Julia code?

I'm generating bindings for a header file from another program, where it has _Atomic declarations. Currently these declarations lead to

[ Info: Parsing headers...
[ Info: Processing header: ...
[ Info: Building the DAG...

ERROR: LoadError: type JuliaUnknown has no field sym
Stacktrace:
 [1] getproperty
   @ ./Base.jl:49 [inlined]
 [2] collect_dependent_system_nodes!(dag::ExprDAG, type::Clang.CLRecord, system_nodes::Dict{ExprNode, Int64})
   @ Clang.Generators ~/.julia/packages/Clang/kqsoL/src/generator/system_deps.jl:138
 [3] collect_dependent_system_nodes!(dag::ExprDAG, node::ExprNode{Clang.Generators.StructDefinition, Clang.CLStructDecl}, system_nodes::Dict{ExprNode, Int64})
   @ Clang.Generators ~/.julia/packages/Clang/kqsoL/src/generator/system_deps.jl:124
 [4] (::CollectDependentSystemNode)(dag::ExprDAG, options::Dict{String, Any})
   @ Clang.Generators ~/.julia/packages/Clang/kqsoL/src/generator/passes.jl:77
 [5] build!(ctx::Context, stage::Clang.Generators.BuildStage)
   @ Clang.Generators ~/.julia/packages/Clang/kqsoL/src/generator/context.jl:181
 [6] build!(ctx::Context)
   @ Clang.Generators ~/.julia/packages/Clang/kqsoL/src/generator/context.jl:172
 [7] top-level scope
   @ ~/Projects/test/generator.jl:27
 [8] include(fname::String)
   @ Main ./sysimg.jl:38
 [9] top-level scope
   @ REPL[6]:1

I tried output_ignorelist and it does not work. This error also doesn't say which symbols are causing issues.

The header file is https://github.com/leanprover/lean4/blob/master/src/include/lean/lean.h .

[JamesWrigley]

So output_ignorelist only affects the printing stage, and this error is coming from earlier in the pipeline so I guess that's why it's not helping. From looking at the stacktrace it seems that it's happening when Clang.jl is figuring out the dependencies of all the symbols so they can printed in the right order. In general this function should probably have a check for JuliaUnknown types and error out with a better message:

Clang.jl/src/generator/system_deps.jl

Line 130 in f7420d7

jlty = tojulia(ty)

AFAIK there's no way to ignore symbols during the build stage.

[Gnimuc]

The default mode can only parse strict C code, but the header file is a C++ header file with "extern C" for C API.

There is an experimental C++ mode which can be enabled by is_cxx=true, but in this way you might get other errors.

Clang.jl/src/generator/context.jl

Line 244 in f7420d7

function get_default_args(triple=get_triple(); is_cxx=false, version=GCC_MIN_VER)

Another way is to use @add_def _Atomic to add the definition and then ignore it by using utput_ignorelist.

[Gnimuc]

AFAIK there's no way to ignore symbols during the build stage.

The original design was actually to let users do custom translation by themselves. (we didn't ship system headers back then, so it's likely missing symbols in the process of parsing)

https://github.com/JuliaInterop/Clang.jl/blob/master/src/generator/definitions.jl

They can subtype AbstractJuliaType and add specialization to translate for the new type.

[lenianiva]

The default mode can only parse strict C code, but the header file is a C++ header file with "extern C" for C API.

There is an experimental C++ mode which can be enabled by is_cxx=true, but in this way you might get other errors.

Clang.jl/src/generator/context.jl

Line 244 in f7420d7
function get_default_args(triple=get_triple(); is_cxx=false, version=GCC_MIN_VER)

Another way is to use @add_def _Atomic to add the definition and then ignore it by using utput_ignorelist.

For now I circumvented the problem with defining _Atomic(x) to x...