From f877b031e8a6adc5db2530cc63f69be1c5633381 Mon Sep 17 00:00:00 2001 From: Tristan Gingold Date: Fri, 16 Sep 2011 15:41:09 +0000 Subject: [PATCH] 2011-09-16 Tristan Gingold * fork-child.c (fork_inferior): Update comment. Use alloca instead of xmalloc for argv. Move len and shell_command declarations in the block where they are used. Only call execvp. Factorize failure code. --- gdb/ChangeLog | 7 ++++ gdb/fork-child.c | 89 ++++++++++++++++++++---------------------------- 2 files changed, 44 insertions(+), 52 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 5108ef1e41a..a881b4737f9 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2011-09-16 Tristan Gingold + + * fork-child.c (fork_inferior): Update comment. Use alloca + instead of xmalloc for argv. Move len and shell_command + declarations in the block where they are used. + Only call execvp. Factorize failure code. + 2011-09-16 Abhijit Halder Code cleanup. diff --git a/gdb/fork-child.c b/gdb/fork-child.c index bb173e7cac9..5dbf1f750fb 100644 --- a/gdb/fork-child.c +++ b/gdb/fork-child.c @@ -126,9 +126,7 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env, void (*pre_trace_fun) (void), char *shell_file_arg) { int pid; - char *shell_command; static char default_shell_file[] = SHELL_FILE; - int len; /* Set debug_fork then attach to the child while it sleeps, to debug. */ static int debug_fork = 0; /* This is set to the result of setpgrp, which if vforked, will be visible @@ -141,6 +139,8 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env, static char **argv; const char *inferior_io_terminal = get_inferior_io_terminal (); struct inferior *inf; + int i; + int save_errno; /* If no exec file handed to us, get it from the exec-file command -- with a good, common error message if none is specified. */ @@ -162,16 +162,6 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env, shell = 1; } - /* Multiplying the length of exec_file by 4 is to account for the - fact that it may expand when quoted; it is a worst-case number - based on every character being '. */ - len = 5 + 4 * strlen (exec_file) + 1 + strlen (allargs) + 1 + /*slop */ 12; - if (exec_wrapper) - len += strlen (exec_wrapper) + 1; - - shell_command = (char *) alloca (len); - shell_command[0] = '\0'; - if (!shell) { /* We're going to call execvp. Create argument vector. @@ -180,18 +170,29 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env, argument. */ int argc = (strlen (allargs) + 1) / 2 + 2; - argv = (char **) xmalloc (argc * sizeof (*argv)); + argv = (char **) alloca (argc * sizeof (*argv)); argv[0] = exec_file; breakup_args (allargs, &argv[1]); } else { /* We're going to call a shell. */ - + char *shell_command; + int len; char *p; int need_to_quote; const int escape_bang = escape_bang_in_quoted_argument (shell_file); + /* Multiplying the length of exec_file by 4 is to account for the + fact that it may expand when quoted; it is a worst-case number + based on every character being '. */ + len = 5 + 4 * strlen (exec_file) + 1 + strlen (allargs) + 1 + /*slop */ 12; + if (exec_wrapper) + len += strlen (exec_wrapper) + 1; + + shell_command = (char *) alloca (len); + shell_command[0] = '\0'; + strcat (shell_command, "exec "); /* Add any exec wrapper. That may be a program name with arguments, so @@ -257,6 +258,16 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env, strcat (shell_command, " "); strcat (shell_command, allargs); + + /* If we decided above to start up with a shell, we exec the + shell, "-c" says to interpret the next arg as a shell command + to execute, and this command is "exec + ". */ + argv = (char **) alloca (4 * sizeof (char *)); + argv[0] = shell_file; + argv[1] = "-c"; + argv[2] = shell_command; + argv[3] = (char *) 0; } /* On some systems an exec will fail if the executable is open. */ @@ -348,44 +359,18 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env, path to find $SHELL. Rich Pixley says so, and I agree. */ environ = env; - /* If we decided above to start up with a shell, we exec the - shell, "-c" says to interpret the next arg as a shell command - to execute, and this command is "exec - ". */ - if (shell) - { - execlp (shell_file, shell_file, "-c", shell_command, (char *) 0); - - /* If we get here, it's an error. */ - fprintf_unfiltered (gdb_stderr, "Cannot exec %s: %s.\n", shell_file, - safe_strerror (errno)); - gdb_flush (gdb_stderr); - _exit (0177); - } - else - { - /* Otherwise, we directly exec the target program with - execvp. */ - int i; - - execvp (exec_file, argv); - - /* If we get here, it's an error. */ - safe_strerror (errno); - fprintf_unfiltered (gdb_stderr, "Cannot exec %s ", exec_file); - - i = 1; - while (argv[i] != NULL) - { - if (i != 1) - fprintf_unfiltered (gdb_stderr, " "); - fprintf_unfiltered (gdb_stderr, "%s", argv[i]); - i++; - } - fprintf_unfiltered (gdb_stderr, ".\n"); - gdb_flush (gdb_stderr); - _exit (0177); - } + execvp (argv[0], argv); + + /* If we get here, it's an error. */ + save_errno = errno; + fprintf_unfiltered (gdb_stderr, "Cannot exec %s", exec_file); + for (i = 1; argv[i] != NULL; i++) + fprintf_unfiltered (gdb_stderr, " %s", argv[i]); + fprintf_unfiltered (gdb_stderr, ".\n"); + fprintf_unfiltered (gdb_stderr, "Error: %s\n", + safe_strerror (save_errno)); + gdb_flush (gdb_stderr); + _exit (0177); } /* Restore our environment in case a vforked child clob'd it. */ -- 2.30.2