Re: [PATCH v2 1/6] Unify shell-finding logic

[Sergio Durigan Junior <sergiodj@redhat.com>]

On Thursday, October 18 2018, Tom Tromey wrote:

> I noticed several places in gdb that were using getenv("SHELL") and
> then falling back to "/bin/sh" if it returned NULL.  This unifies
> these into a single function.

Not sure if I reviewed this one before, but it LGTM (with a very small
nit below).  It also can be pushed independently, IMO.

Thanks,

> gdb/ChangeLog
> 2018-10-18  Tom Tromey  <tom@tromey.com>
>
> 	* procfs.c (procfs_target::create_inferior): Use get_shell.
> 	* cli/cli-cmds.c (shell_escape): Use get_shell.
> 	* windows-nat.c (windows_nat_target::create_inferior): Use
> 	get_shell.
> 	* common/pathstuff.c (get_shell): New function.
> 	* nat/fork-inferior.c (SHELL_FILE, get_startup_shell): Remove.
> 	(fork_inferior): Use get_shell.
> 	* common/pathstuff.h (get_shell): Declare.
> ---
>  gdb/ChangeLog           | 11 +++++++++++
>  gdb/cli/cli-cmds.c      |  6 ++----
>  gdb/common/pathstuff.c  | 12 ++++++++++++
>  gdb/common/pathstuff.h  |  4 ++++
>  gdb/nat/fork-inferior.c | 21 ++-------------------
>  gdb/procfs.c            |  4 ++--
>  gdb/windows-nat.c       |  5 ++---
>  7 files changed, 35 insertions(+), 28 deletions(-)
>
> diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
> index b871e476d3..135f550b80 100644
> --- a/gdb/cli/cli-cmds.c
> +++ b/gdb/cli/cli-cmds.c
> @@ -50,6 +50,7 @@
>  #include "cli/cli-utils.h"
>  
>  #include "extension.h"
> +#include "common/pathstuff.h"
>  
>  #ifdef TUI
>  #include "tui/tui.h"	/* For tui_active et.al.  */
> @@ -726,13 +727,10 @@ shell_escape (const char *arg, int from_tty)
>  
>    if ((pid = vfork ()) == 0)
>      {
> -      const char *p, *user_shell;
> +      const char *p, *user_shell = get_shell ();
>  
>        close_most_fds ();
>  
> -      if ((user_shell = getenv ("SHELL")) == NULL)
> -	user_shell = "/bin/sh";
> -
>        /* Get the name of the shell for arg0.  */
>        p = lbasename (user_shell);
>  
> diff --git a/gdb/common/pathstuff.c b/gdb/common/pathstuff.c
> index 82905c9e68..6d8e53f4e1 100644
> --- a/gdb/common/pathstuff.c
> +++ b/gdb/common/pathstuff.c
> @@ -190,3 +190,15 @@ get_standard_cache_dir ()
>  
>    return {};
>  }
> +
> +/* See common/pathstuff.h.  */
> +
> +const char *
> +get_shell ()
> +{
> +  const char *ret = getenv ("SHELL");
> +  if (ret == NULL)
> +    ret = "/bin/sh";
> +
> +  return ret;
> +}
> diff --git a/gdb/common/pathstuff.h b/gdb/common/pathstuff.h
> index a43b963651..40fbda8d85 100644
> --- a/gdb/common/pathstuff.h
> +++ b/gdb/common/pathstuff.h
> @@ -64,4 +64,8 @@ extern bool contains_dir_separator (const char *path);
>  
>  extern std::string get_standard_cache_dir ();
>  
> +/* Return the file name of the user's shell.  */

WDYT about explicitly mentioning here that "user's shell" means "the
SHELL environment variable"?

> +
> +extern const char *get_shell ();
> +
>  #endif /* PATHSTUFF_H */
> diff --git a/gdb/nat/fork-inferior.c b/gdb/nat/fork-inferior.c
> index 40cd05a0f8..f1032b43c9 100644
> --- a/gdb/nat/fork-inferior.c
> +++ b/gdb/nat/fork-inferior.c
> @@ -24,16 +24,13 @@
>  #include "target/target.h"
>  #include "common-inferior.h"
>  #include "common-gdbthread.h"
> +#include "common/pathstuff.h"
>  #include "signals-state-save-restore.h"
>  #include "gdb_tilde_expand.h"
>  #include <vector>
>  
>  extern char **environ;
>  
> -/* Default shell file to be used if 'startup-with-shell' is set but
> -   $SHELL is not.  */
> -#define SHELL_FILE "/bin/sh"
> -
>  /* Build the argument vector for execv(3).  */
>  
>  class execv_argv
> @@ -265,20 +262,6 @@ execv_argv::init_for_shell (const char *exec_file,
>    m_argv.push_back (NULL);
>  }
>  
> -/* Return the shell that must be used to startup the inferior.  The
> -   first attempt is the environment variable SHELL; if it is not set,
> -   then we default to SHELL_FILE.  */
> -
> -static const char *
> -get_startup_shell ()
> -{
> -  const char *ret = getenv ("SHELL");
> -  if (ret == NULL)
> -    ret = SHELL_FILE;
> -
> -  return ret;
> -}
> -
>  /* See nat/fork-inferior.h.  */
>  
>  pid_t
> @@ -316,7 +299,7 @@ fork_inferior (const char *exec_file_arg, const std::string &allargs,
>  
>        /* Figure out what shell to start up the user program under.  */
>        if (shell_file == NULL)
> -	shell_file = get_startup_shell ();
> +	shell_file = get_shell ();
>  
>        gdb_assert (shell_file != NULL);
>      }
> diff --git a/gdb/procfs.c b/gdb/procfs.c
> index 6ffe569e69..ca381a71ae 100644
> --- a/gdb/procfs.c
> +++ b/gdb/procfs.c
> @@ -3035,11 +3035,11 @@ procfs_target::create_inferior (const char *exec_file,
>  				const std::string &allargs,
>  				char **env, int from_tty)
>  {
> -  char *shell_file = getenv ("SHELL");
> +  const char *shell_file = get_shell ();
>    char *tryname;
>    int pid;
>  
> -  if (shell_file != NULL && strchr (shell_file, '/') == NULL)
> +  if (strchr (shell_file, '/') == NULL)
>      {
>  
>        /* We will be looking down the PATH to find shell_file.  If we
> diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
> index 0047a26418..8292cf4212 100644
> --- a/gdb/windows-nat.c
> +++ b/gdb/windows-nat.c
> @@ -68,6 +68,7 @@
>  #include "complaints.h"
>  #include "inf-child.h"
>  #include "gdb_tilde_expand.h"
> +#include "common/pathstuff.h"
>  
>  #define AdjustTokenPrivileges		dyn_AdjustTokenPrivileges
>  #define DebugActiveProcessStop		dyn_DebugActiveProcessStop
> @@ -2578,9 +2579,7 @@ windows_nat_target::create_inferior (const char *exec_file,
>      }
>    else
>      {
> -      sh = getenv ("SHELL");
> -      if (!sh)
> -	sh = "/bin/sh";
> +      sh = get_shell ();
>        if (cygwin_conv_path (CCP_POSIX_TO_WIN_W, sh, shell, __PMAX) < 0)
>        	error (_("Error starting executable via shell: %d"), errno);
>  #ifdef __USEWIDE
> -- 
> 2.17.1

-- 
Sergio
GPG key ID: 237A 54B1 0287 28BF 00EF  31F4 D0EB 7628 65FC 5E36
Please send encrypted e-mail if possible
http://sergiodj.net/