http://sourceware.org/ml/gdb-patches/2008-12/msg00243.html Check return values of functions declared with warn_unused_result attribute in GLIBC 2.8. * cli/cli-cmds.c (pwd_command): Check return value from getcwd. * inflow.c (check_syscall): New function. (new_tty): Use check_syscall to check return values from open and dup. * linux-nat.c (linux_nat_info_proc_cmd): Check return value from fgets. * main.c (captured_main): Call cwd after setting up gdb_stderr; check for errors from getcwd. * mi/mi-cmd-env.c (mi_cmd_env_pwd): Check return value from getcwd. * ui-file.c (stdio_file_write): Check return value from fwrite. (stdio_file_fputs): Check return value from fputs. * utils.c (internal_vproblem): abort if last-ditch error message write fails. [ +linespec.c: Fedora patch. ] [ +top.c: Fedora patch. ] ui-file.c replaced by: http://sourceware.org/ml/gdb-patches/2008-12/msg00260.html --- gdb/ChangeLog | 14 ++++++++++++++ gdb/cli/cli-cmds.c | 4 +++- gdb/inflow.c | 22 ++++++++++++++-------- gdb/linux-nat.c | 6 ++++-- gdb/main.c | 12 +++++++++--- gdb/mi/mi-cmd-env.c | 5 ++++- gdb/ui-file.c | 6 ++++-- gdb/utils.c | 8 +++++++- 8 files changed, 59 insertions(+), 18 deletions(-) diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c index 806a68a..b80bdfc 100644 --- a/gdb/cli/cli-cmds.c +++ b/gdb/cli/cli-cmds.c @@ -323,7 +323,9 @@ pwd_command (char *args, int from_tty) { if (args) error (_("The \"pwd\" command does not take an argument: %s"), args); - getcwd (gdb_dirbuf, sizeof (gdb_dirbuf)); + if (! getcwd (gdb_dirbuf, sizeof (gdb_dirbuf))) + error (_("Error finding name of working directory: %s"), + safe_strerror (errno)); if (strcmp (gdb_dirbuf, current_directory) != 0) printf_unfiltered (_("Working directory %s\n (canonically %s).\n"), diff --git a/gdb/inflow.c b/gdb/inflow.c index e82514e..7ecb5ab 100644 --- a/gdb/inflow.c +++ b/gdb/inflow.c @@ -523,6 +523,16 @@ new_tty_prefork (const char *ttyname) inferior_thisrun_terminal = ttyname; } +static void +check_syscall (const char *msg, int result) +{ + if (result < 0) + { + print_sys_errmsg (msg, errno); + _exit (1); + } +} + void new_tty (void) { @@ -549,27 +559,23 @@ new_tty (void) /* Now open the specified new terminal. */ tty = open (inferior_thisrun_terminal, O_RDWR | O_NOCTTY); - if (tty == -1) - { - print_sys_errmsg (inferior_thisrun_terminal, errno); - _exit (1); - } + check_syscall (inferior_thisrun_terminal, tty); /* Avoid use of dup2; doesn't exist on all systems. */ if (tty != 0) { close (0); - dup (tty); + check_syscall ("dup'ing tty into fd 0", dup (tty)); } if (tty != 1) { close (1); - dup (tty); + check_syscall ("dup'ing tty into fd 1", dup (tty)); } if (tty != 2) { close (2); - dup (tty); + check_syscall ("dup'ing tty into fd 2", dup (tty)); } #ifdef TIOCSCTTY diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index 913bfec..a829eb8 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -3666,8 +3666,10 @@ linux_nat_info_proc_cmd (char *args, int from_tty) if ((procfile = fopen (fname1, "r")) != NULL) { struct cleanup *cleanup = make_cleanup_fclose (procfile); - fgets (buffer, sizeof (buffer), procfile); - printf_filtered ("cmdline = '%s'\n", buffer); + if (fgets (buffer, sizeof (buffer), procfile)) + printf_filtered ("cmdline = '%s'\n", buffer); + else + warning (_("unable to read '/proc/%lld/cmdline'"), pid); do_cleanups (cleanup); } else diff --git a/gdb/main.c b/gdb/main.c index a53002d..a9fd988 100644 --- a/gdb/main.c +++ b/gdb/main.c @@ -195,9 +195,6 @@ captured_main (void *data) line[0] = '\0'; /* Terminate saved (now empty) cmd line */ instream = stdin; - getcwd (gdb_dirbuf, sizeof (gdb_dirbuf)); - current_directory = gdb_dirbuf; - gdb_stdout = stdio_fileopen (stdout); gdb_stderr = stdio_fileopen (stderr); gdb_stdlog = gdb_stderr; /* for moment */ @@ -206,6 +203,15 @@ captured_main (void *data) gdb_stdtargerr = gdb_stderr; /* for moment */ gdb_stdtargin = gdb_stdin; /* for moment */ + if (! getcwd (gdb_dirbuf, sizeof (gdb_dirbuf))) + /* Don't use *_filtered or warning() (which relies on + current_target) until after initialize_all_files(). */ + fprintf_unfiltered (gdb_stderr, + _("%s: warning: error finding working directory: %s\n"), + argv[0], safe_strerror (errno)); + + current_directory = gdb_dirbuf; + /* Set the sysroot path. */ #ifdef TARGET_SYSTEM_ROOT_RELOCATABLE gdb_sysroot = make_relative_prefix (argv[0], BINDIR, TARGET_SYSTEM_ROOT); diff --git a/gdb/mi/mi-cmd-env.c b/gdb/mi/mi-cmd-env.c index 327ddc5..0103153 100644 --- a/gdb/mi/mi-cmd-env.c +++ b/gdb/mi/mi-cmd-env.c @@ -78,7 +78,10 @@ mi_cmd_env_pwd (char *command, char **argv, int argc) /* Otherwise the mi level is 2 or higher. */ - getcwd (gdb_dirbuf, sizeof (gdb_dirbuf)); + if (! getcwd (gdb_dirbuf, sizeof (gdb_dirbuf))) + error (_("mi_cmd_env_pwd: error finding name of working directory: %s"), + safe_strerror (errno)); + ui_out_field_string (uiout, "cwd", gdb_dirbuf); } diff --git a/gdb/utils.c b/gdb/utils.c index d14009f..725f00b 100644 --- a/gdb/utils.c +++ b/gdb/utils.c @@ -865,7 +865,13 @@ internal_vproblem (struct internal_problem *problem, abort (); /* NOTE: GDB has only three calls to abort(). */ default: dejavu = 3; - write (STDERR_FILENO, msg, sizeof (msg)); + /* Newer GLIBC versions put the warn_unused_result attribute + on write, but this is one of those rare cases where + ignoring the return value is correct. Casting to (void) + does not fix this problem. This is the solution suggested + at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25509. */ + if (write (STDERR_FILENO, msg, sizeof (msg)) != sizeof (msg)) + abort (); exit (1); } } Index: gdb-6.7/gdb/linespec.c =================================================================== --- gdb-6.7.orig/gdb/linespec.c 2007-10-14 23:31:03.000000000 +0200 +++ gdb-6.7/gdb/linespec.c 2007-10-14 23:53:57.000000000 +0200 @@ -1654,7 +1654,7 @@ static struct symtabs_and_lines find_method (int funfirstline, char ***canonical, char *saved_arg, char *copy, struct type *t, struct symbol *sym_class) { - struct symtabs_and_lines values; + struct symtabs_and_lines values = { NULL }; struct symbol *sym = NULL; int i1; /* Counter for the symbol array. */ struct symbol **sym_arr = alloca (total_number_of_methods (t) Index: gdb-6.7/gdb/top.c =================================================================== --- gdb-6.7.orig/gdb/top.c 2007-10-14 23:38:27.000000000 +0200 +++ gdb-6.7/gdb/top.c 2007-10-14 23:42:39.000000000 +0200 @@ -1636,7 +1636,8 @@ gdb_init (char *argv0) /* Run the init function of each source file */ - getcwd (gdb_dirbuf, sizeof (gdb_dirbuf)); + /* Unused result. */ + 1 && getcwd (gdb_dirbuf, sizeof (gdb_dirbuf)); current_directory = gdb_dirbuf; #ifdef __MSDOS__ --- ./gdb/ui-file.c 1 Jan 2008 22:53:13 -0000 1.15 +++ ./gdb/ui-file.c 14 Dec 2008 18:16:56 -0000 @@ -481,7 +481,9 @@ stdio_file_write (struct ui_file *file, if (stdio->magic != &stdio_file_magic) internal_error (__FILE__, __LINE__, _("stdio_file_write: bad magic number")); - fwrite (buf, length_buf, 1, stdio->file); + /* Calling error crashes when we are called from the exception framework. */ + if (fwrite (buf, length_buf, 1, stdio->file)) + ; } static void @@ -491,7 +493,9 @@ stdio_file_fputs (const char *linebuffer if (stdio->magic != &stdio_file_magic) internal_error (__FILE__, __LINE__, _("stdio_file_fputs: bad magic number")); - fputs (linebuffer, stdio->file); + /* Calling error crashes when we are called from the exception framework. */ + if (fputs (linebuffer, stdio->file)) + ; } static int