binutils-gdb/gdbsupport/common-inferior.h
Simon Marchi 7831bc9185 gdb: remove get_exec_file
I believe that the get_exec_file function is unnecessary, and the code
can be simplified if we remove it.

Consider for instance when you "run" a program on Linux with native
debugging.

 1. run_command_1 obtains the executable file from
    `current_program_space->exec_filename ()`
 2. it passes it to `run_target->create_inferior()`, which is
    `inf_ptrace_target::create_inferior()` in this case, which then
    passes it to `fork_inferior()`
 3. `fork_inferior()` then has a fallback, where if the passed exec file
    is nullptr, it gets its from `get_exec_file()`.
 4. `get_exec_file()` returns `current_program_space->exec_filename ()`
    - just like the things we started with - or errors out if the
    current program space doesn't have a specified executable.

If there's no exec filename passed in step 1, there's not going to be
any in step 4, so it seems pointless to call `get_exec_file()`, we could
just error out when `exec_file` is nullptr.  But we can't error out
directly in `fork_inferior()`, since the error is GDB-specific, and that
function is shared with GDBserver.

Speaking of GDBserver, all code paths that lead to `fork_inferior()`
provide a non-nullptr exec file.

Therefore, to simplify things:

 - Make `fork_inferior()` assume that the passed exec file is not
   nullptr, don't call `get_exec_file()`
 - Change some targets (darwin-nat, go32-nat, gnu-nat, inf-ptrace,
   nto-procfs, procfs) to error out when the exec file passed to their
   create_inferior method is nullptr.  Some targets are fine with a
   nullptr exec file, so we can't check that in `run_command_1()`.
 - Add the `no_executable_specified_error()` function, which re-uses the
   error message that `get_exec_file()` had.
 - Change some targets (go32-nat, nto-procfs) to not call
   `get_exec_file()`, since it's pointless for the same reason as in the
   example above, if it returns, it's going the be the same value as the
   `exec_file` parameter.  Just rely on `exec_file`.
 - Remove the final use of `get_exec_file()`, in `load_command()`.
 - Remove the `get_exec_file()` implementations in GDB and GDBserver and
   remove the shared declaration.

Change-Id: I601c16498e455f7baa1f111a179da2f6c913baa3
Approved-By: Tom Tromey <tom@tromey.com>
2024-06-07 23:09:03 -04:00

61 lines
2.0 KiB
C++

/* Functions to deal with the inferior being executed on GDB or
GDBserver.
Copyright (C) 1986-2024 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef COMMON_COMMON_INFERIOR_H
#define COMMON_COMMON_INFERIOR_H
#include "gdbsupport/array-view.h"
/* Return the exec wrapper to be used when starting the inferior, or NULL
otherwise. */
extern const char *get_exec_wrapper ();
/* Return the inferior's current working directory.
If it is not set, the string is empty. */
extern const std::string &get_inferior_cwd ();
/* Whether to start up the debuggee under a shell.
If startup-with-shell is set, GDB's "run" will attempt to start up
the debuggee under a shell. This also happens when using GDBserver
under extended remote mode.
This is in order for argument-expansion to occur. E.g.,
(gdb) run *
The "*" gets expanded by the shell into a list of files.
While this is a nice feature, it may be handy to bypass the shell
in some cases. To disable this feature, do "set startup-with-shell
false".
The catch-exec traps expected during start-up will be one more if
the target is started up with a shell. */
extern bool startup_with_shell;
/* Compute command-line string given argument vector. This does the
same shell processing as fork_inferior. */
extern std::string
construct_inferior_arguments (gdb::array_view<char * const>);
#endif /* COMMON_COMMON_INFERIOR_H */