sdk/lib/dl/runtime-dynamic-linker.cc

// Copyright 2024 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "runtime-dynamic-linker.h"

namespace dl {

ModuleHandle* RuntimeDynamicLinker::FindModule(Soname name) {
  if (auto it = std::find(loaded_modules_.begin(), loaded_modules_.end(), name);
      it != loaded_modules_.end()) {
    // TODO(https://fxbug.dev/328135195): increase reference count.
    // TODO(https://fxbug.dev/326120230): update flags
    ModuleHandle& found = *it;
    return &found;
  }
  return nullptr;
}

fit::result<Error, ModuleHandle*> RuntimeDynamicLinker::CheckOpen(const char* file, int mode) {
  if (mode & ~(kOpenSymbolScopeMask | kOpenBindingModeMask | kOpenFlagsMask)) {
    return fit::error{Error{"invalid mode parameter"}};
  }
  if (!file || !strlen(file)) {
    return fit::error{Error{"TODO(https://fxbug.dev/324136831): nullptr for file is unsupported."}};
  }
  return fit::ok(FindModule(Soname{file}));
}

fit::result<Error, void*> RuntimeDynamicLinker::LookupSymbol(ModuleHandle* module,
                                                             const char* ref) {
  Diagnostics diag;
  elfldltl::SymbolName name{ref};
  if (const auto* sym = name.Lookup(module->symbol_info())) {
    if (sym->type() == elfldltl::ElfSymType::kTls) {
      diag.SystemError(
          "TODO(https://fxbug.dev/331421403): TLS semantics for dlsym() are not supported yet.");
      return diag.take_error();
    }
    return diag.ok(reinterpret_cast<void*>(sym->value + module->load_bias()));
  }
  diag.UndefinedSymbol(ref);
  return diag.take_error();
}

}  // namespace dl