path: root/src/nvim/api/private/helpers.c

// This is an open source non-commercial project. Dear PVS-Studio, please check
// it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com

#include <assert.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>

#include "nvim/api/private/converter.h"
#include "nvim/api/private/defs.h"
#include "nvim/api/private/helpers.h"
#include "nvim/api/vim.h"
#include "nvim/ascii.h"
#include "nvim/assert.h"
#include "nvim/buffer.h"
#include "nvim/charset.h"
#include "nvim/decoration.h"
#include "nvim/eval.h"
#include "nvim/eval/typval.h"
#include "nvim/extmark.h"
#include "nvim/fileio.h"
#include "nvim/getchar.h"
#include "nvim/lib/kvec.h"
#include "nvim/lua/executor.h"
#include "nvim/map.h"
#include "nvim/map_defs.h"
#include "nvim/mark.h"
#include "nvim/memline.h"
#include "nvim/memory.h"
#include "nvim/msgpack_rpc/helpers.h"
#include "nvim/option.h"
#include "nvim/option_defs.h"
#include "nvim/syntax.h"
#include "nvim/ui.h"
#include "nvim/version.h"
#include "nvim/vim.h"
#include "nvim/window.h"

#ifdef INCLUDE_GENERATED_DECLARATIONS
# include "api/private/funcs_metadata.generated.h"
# include "api/private/helpers.c.generated.h"
# include "api/private/ui_events_metadata.generated.h"
#endif

/// Start block that may cause VimL exceptions while evaluating another code
///
/// Used when caller is supposed to be operating when other VimL code is being
/// processed and that “other VimL code” must not be affected.
///
/// @param[out]  tstate  Location where try state should be saved.
void try_enter(TryState *const tstate)
{
  // TODO(ZyX-I): Check whether try_enter()/try_leave() may use
  //              enter_cleanup()/leave_cleanup(). Or
  //              save_dbg_stuff()/restore_dbg_stuff().
  *tstate = (TryState) {
    .current_exception = current_exception,
    .msg_list = (const struct msglist *const *)msg_list,
    .private_msg_list = NULL,
    .trylevel = trylevel,
    .got_int = got_int,
    .need_rethrow = need_rethrow,
    .did_emsg = did_emsg,
  };
  msg_list = &tstate->private_msg_list;
  current_exception = NULL;
  trylevel = 1;
  got_int = false;
  need_rethrow = false;
  did_emsg = false;
}

/// End try block, set the error message if any and restore previous state
///
/// @warning Return is consistent with most functions (false on error), not with
///          try_end (true on error).
///
/// @param[in]  tstate  Previous state to restore.
/// @param[out]  err  Location where error should be saved.
///
/// @return false if error occurred, true otherwise.
bool try_leave(const TryState *const tstate, Error *const err)
  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
{
  const bool ret = !try_end(err);
  assert(trylevel == 0);
  assert(!need_rethrow);
  assert(!got_int);
  assert(!did_emsg);
  assert(msg_list == &tstate->private_msg_list);
  assert(*msg_list == NULL);
  assert(current_exception == NULL);
  msg_list = (struct msglist **)tstate->msg_list;
  current_exception = tstate->current_exception;
  trylevel = tstate->trylevel;
  got_int = tstate->got_int;
  need_rethrow = tstate->need_rethrow;
  did_emsg = tstate->did_emsg;
  return ret;
}

/// Start block that may cause vimscript exceptions
///
/// Each try_start() call should be mirrored by try_end() call.
///
/// To be used as a replacement of `:try … catch … endtry` in C code, in cases
/// when error flag could not already be set. If there may be pending error
/// state at the time try_start() is executed which needs to be preserved,
/// try_enter()/try_leave() pair should be used instead.
void try_start(void)
{
  ++trylevel;
}

/// End try block, set the error message if any and return true if an error
/// occurred.
///
/// @param err Pointer to the stack-allocated error object
/// @return true if an error occurred
bool try_end(Error *err)
{
  // Note: all globals manipulated here should be saved/restored in
  // try_enter/try_leave.
  trylevel--;

  // Set by emsg(), affects aborting().  See also enter_cleanup().
  did_emsg = false;
  force_abort = false;

  if (got_int) {
    if (current_exception) {
      // If we got an interrupt, discard the current exception
      discard_current_exception();
    }

    api_set_error(err, kErrorTypeException, "Keyboard interrupt");
    got_int = false;
  } else if (msg_list != NULL && *msg_list != NULL) {
    int should_free;
    char *msg = (char *)get_exception_string(*msg_list,
                                             ET_ERROR,
                                             NULL,
                                             &should_free);
    api_set_error(err, kErrorTypeException, "%s", msg);
    free_global_msglist();

    if (should_free) {
      xfree(msg);
    }
  } else if (current_exception) {
    api_set_error(err, kErrorTypeException,