Function internalize_pass

crates/rustc_codegen_nvvm/src/nvvm.rs:248–321

(module: &Module, cx: &Context)

}

unsafe fn internalize_pass(module: &Module, cx: &Context) {
    // collect the values of all the declared kernels
    let num_operands =
        LLVMGetNamedMetadataNumOperands(module, "nvvm.annotations\0".as_ptr().cast()) as usize;
    let mut operands = Vec::with_capacity(num_operands);
    LLVMGetNamedMetadataOperands(
        module,
        "nvvm.annotations\0".as_ptr().cast(),
        operands.as_mut_ptr(),
    );
    operands.set_len(num_operands);
    let mut kernels = Vec::with_capacity(num_operands);
    let kernel_str = LLVMMDStringInContext(cx, "kernel".as_ptr().cast(), 6);

    for mdnode in operands {
        let num_operands = LLVMGetMDNodeNumOperands(mdnode) as usize;
        let mut operands = Vec::with_capacity(num_operands);
        LLVMGetMDNodeOperands(mdnode, operands.as_mut_ptr());
        operands.set_len(num_operands);

        if operands.get(1) == Some(&kernel_str) {
            kernels.push(operands[0]);
        }
    }

    // see what functions are marked as externally visible by the user.
    let num_operands =
        LLVMGetNamedMetadataNumOperands(module, "cg_nvvm_used\0".as_ptr().cast()) as usize;
    let mut operands = Vec::with_capacity(num_operands);
    LLVMGetNamedMetadataOperands(
        module,
        "cg_nvvm_used\0".as_ptr().cast(),
        operands.as_mut_ptr(),
    );
    operands.set_len(num_operands);
    let mut used_funcs = Vec::with_capacity(num_operands);

    for mdnode in operands {
        let num_operands = LLVMGetMDNodeNumOperands(mdnode) as usize;
        let mut operands = Vec::with_capacity(num_operands);
        LLVMGetMDNodeOperands(mdnode, operands.as_mut_ptr());
        operands.set_len(num_operands);

        used_funcs.push(operands[0]);
    }

    let iter = FunctionIter::new(&module);
    for func in iter {
        let is_kernel = kernels.contains(&func);
        let is_decl = LLVMIsDeclaration(func) == True;
        let is_used = used_funcs.contains(&func);

        if !is_decl && !is_kernel {
            LLVMRustSetLinkage(func, Linkage::InternalLinkage);
            LLVMRustSetVisibility(func, Visibility::Default);
        }

        // explicitly set it to external just in case the codegen set them to internal for some reason