From 03d83cd5f55abef6a8e6b8e1811cb86f8a05d616 Mon Sep 17 00:00:00 2001 From: Richard Bunt Date: Fri, 31 Mar 2023 15:31:40 +0100 Subject: [PATCH] GDB: Add `info main' command Allow consumers of GDB to extract the name of the main method. This is most useful for Fortran programs which have a variable main method. Used by both MAP and DDT e.g. it is used to detect the presence of debug information. Co-Authored-By: Maciej W. Rozycki --- gdb/NEWS | 3 ++ gdb/doc/gdb.texinfo | 6 ++++ gdb/symtab.c | 11 +++++++ gdb/testsuite/gdb.fortran/info-main.exp | 42 +++++++++++++++++++++++++ gdb/testsuite/gdb.fortran/info-main.f90 | 19 +++++++++++ 5 files changed, 81 insertions(+) create mode 100644 gdb/testsuite/gdb.fortran/info-main.exp create mode 100644 gdb/testsuite/gdb.fortran/info-main.f90 diff --git a/gdb/NEWS b/gdb/NEWS index ba5ae520112..10a1a70fa52 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -83,6 +83,9 @@ show always-read-ctf When off, CTF is only read if DWARF is not present. When on, CTF is read regardless of whether DWARF is present. Off by default. +info main + Get main symbol to identify entry point into program. + * New convenience function "$_shell", to execute a shell command and return the result. This lets you run shell commands in expressions. Some examples: diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 92d99349dbf..fe76e5e0a0e 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -20162,6 +20162,12 @@ The optional flag @samp{-q}, which stands for @samp{quiet}, disables printing header information and messages explaining why no functions or variables have been printed. +@kindex info main +@item info main +Print the name of the starting function of the program. This serves +primarily Fortran programs, which have a user-supplied name for the +main subroutine. + @kindex info classes @cindex Objective-C, classes and selectors @item info classes diff --git a/gdb/symtab.c b/gdb/symtab.c index 42e7f5cd908..9e9798676cb 100644 --- a/gdb/symtab.c +++ b/gdb/symtab.c @@ -5282,6 +5282,14 @@ info_modules_command (const char *args, int from_tty) from_tty); } +/* Implement the 'info main' command. */ + +static void +info_main_command (const char *args, int from_tty) +{ + gdb_printf ("%s\n", main_name ()); +} + static void rbreak_command (const char *regexp, int from_tty) { @@ -6873,6 +6881,9 @@ Options:\n\ _("All module names, or those matching REGEXP.")); set_cmd_completer_handle_brkchars (c, info_types_command_completer); + add_info ("main", info_main_command, + _("Get main symbol to identify entry point into program.")); + add_basic_prefix_cmd ("module", class_info, _("\ Print information about modules."), &info_module_cmdlist, 0, &infolist); diff --git a/gdb/testsuite/gdb.fortran/info-main.exp b/gdb/testsuite/gdb.fortran/info-main.exp new file mode 100644 index 00000000000..a182dac9e41 --- /dev/null +++ b/gdb/testsuite/gdb.fortran/info-main.exp @@ -0,0 +1,42 @@ +# Copyright 2023 Free Software Foundation, Inc. + +# 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 . + +require allow_fortran_tests + +load_lib fortran.exp + +standard_testfile .f90 + +set old_gdbflags $GDBFLAGS +set GDBFLAGS [string map {"-readnow" ""} "$GDBFLAGS"] + +if {[prepare_for_testing ${testfile}.exp ${testfile} ${srcfile} {debug f90}]} { + return -1 +} + +gdb_test "info main" "simple" "info main prior to start" + +if ![fortran_runto_main] { + untested "could not run to main" + return -1 +} + +gdb_test "info main" "simple" "info main post start" + +set GDBFLAGS "$GDBFLAGS -readnow" +clean_restart $testfile +gdb_test "info main" "simple" "info main with readnow" + +set GDBFLAGS $old_gdbflags diff --git a/gdb/testsuite/gdb.fortran/info-main.f90 b/gdb/testsuite/gdb.fortran/info-main.f90 new file mode 100644 index 00000000000..5cd5879f9b4 --- /dev/null +++ b/gdb/testsuite/gdb.fortran/info-main.f90 @@ -0,0 +1,19 @@ +! Copyright 2023 Free Software Foundation, Inc. +! +! 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 . + +program simple + implicit none + print *, "Nothing." +end program simple -- 2.30.2