[PATCH 6/7] gdb/fortran: Add new 'info modules' command

Andrew Burgess
2019-07-27T16:23:05Z

Add a new command 'info modules' that lists all of the modules GDB
knows about from the debug information.

A module is a debugging entity in the DWARF defined with
DW_TAG_module, currently Fortran is known to use this tag for its
modules. I'm not aware of any other language that currently makes use
of DW_TAG_module.

The output style is similar to the 'info type' output:

(gdb) info modules
All defined modules:

File info-types.f90:
16: mod1
24: mod2
(gdb)

Where the user is told the file the module is defined in and, on the
left hand side, the line number at which the module is defined along
with the name of the module.

This patch is a new implementation of an idea originally worked on by
Mark O'Connor, Chris January, David Lecomber, and Xavier Oro from ARM.

gdb/ChangeLog:

* dwarf2read.c (dw2_debug_names_iterator::next): Handle
MODULES_DOMAIN.
* psymtab.c (recursively_search_psymtabs): Likewise.
* symtab.c (search_domain_name): Likewise.
(search_symbols): Likewise.
(print_symbol_info): Likewise.
(symtab_symbol_info): Likewise.
(info_modules_command): New function.
(_initialize_symtab): Register 'info modules' command.
* symtab.h (enum search_domain): Add MODULES_DOMAIN.
* NEWS: Mention new 'info modules' command.

gdb/doc/ChangeLog:

* gdb.texinfo (Symbols): Document new 'info modules' command.

gdb/testsuite/ChangeLog:

* gdb.fortran/info-modules.exp: New file.
* gdb.fortran/info-types.exp: Update expected results.
* gdb.fortran/info-types.f90: Extend with extra module.
---
gdb/ChangeLog | 14 +++++++
gdb/NEWS | 6 +++
gdb/doc/ChangeLog | 4 ++
gdb/doc/gdb.texinfo | 16 ++++++++
gdb/dwarf2read.c | 8 ++++
gdb/psymtab.c | 2 +
gdb/symtab.c | 36 ++++++++++++++++--
gdb/symtab.h | 5 ++-
gdb/testsuite/ChangeLog | 6 +++
gdb/testsuite/gdb.fortran/info-modules.exp | 61 ++++++++++++++++++++++++++++++
gdb/testsuite/gdb.fortran/info-types.exp | 2 +-
gdb/testsuite/gdb.fortran/info-types.f90 | 5 +++
12 files changed, 159 insertions(+), 6 deletions(-)
create mode 100644 gdb/testsuite/gdb.fortran/info-modules.exp

diff --git a/gdb/NEWS b/gdb/NEWS
index 40b56727227..14c931602f4 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -104,6 +104,12 @@ maint show test-settings KIND
A set of commands used by the testsuite for exercising the settings
infrastructure.

+info modules [-q] [REGEXP]
+ Return a list of modules matching REGEXP, or all modules if no
+ REGEXP is given. Only languages that generate DW_TAG_module in
+ their DWARF (for example Fortran) will give any results for this
+ command.
+
* Changed commands

help
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index c7f7abd9e87..71ee20f29d5 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -18617,6 +18617,22 @@
is printed only if its name matches @var{regexp} and its type matches
@var{type_regexp}.

+@kindex info modules
+@cindex modules
+@item info modules [-q] [@var{regexp}]
+List all modules for which there is debugging information available.
+Modules are identified by @code{DW_TAG_module} in DWARF debugging
+information, only languages that use this tag will list modules with
+this command. Currently Fortran is known to generate module
+information in its debug.
+
+If the optional @var{regexp} is provided then only modules whose name
+matches @var{regexp} will be listed.
+
+The optional flag @samp{-q}, which stands for @samp{quiet}, disables
+printing header information and messages explaining why no functions
+have been printed.
+
@kindex info classes
@cindex Objective-C, classes and selectors
@item info classes
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 01cab752888..00012877da1 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -6004,6 +6004,14 @@ dw2_debug_names_iterator::next ()
goto again;
}
break;
+ case MODULES_DOMAIN:
+ switch (indexval.dwarf_tag)
+ {
+ case DW_TAG_module:
+ break;
+ default:
+ goto again;
+ }
default:
break;
}
diff --git a/gdb/psymtab.c b/gdb/psymtab.c
index 6cc7566580a..95615e30f68 100644
--- a/gdb/psymtab.c
+++ b/gdb/psymtab.c
@@ -1301,6 +1301,8 @@ recursively_search_psymtabs
QUIT;

if ((domain == ALL_DOMAIN
+ || (domain == MODULES_DOMAIN
+ && (*psym)->domain == MODULE_DOMAIN)
|| (domain == VARIABLES_DOMAIN
&& (*psym)->aclass != LOC_TYPEDEF
&& (*psym)->aclass != LOC_BLOCK)
diff --git a/gdb/symtab.c b/gdb/symtab.c
index d3a209608b7..793be13ab9d 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -297,6 +297,7 @@ search_domain_name (enum search_domain e)
case VARIABLES_DOMAIN: return "VARIABLES_DOMAIN";
case FUNCTIONS_DOMAIN: return "FUNCTIONS_DOMAIN";
case TYPES_DOMAIN: return "TYPES_DOMAIN";
+ case MODULES_DOMAIN: return "MODULES_DOMAIN";
case ALL_DOMAIN: return "ALL_DOMAIN";
default: gdb_assert_not_reached ("bad search_domain");
}
@@ -4365,7 +4366,7 @@ search_symbols (const char *regexp, enum search_domain kind,
gdb::optional<compiled_regex> preg;
gdb::optional<compiled_regex> treg;

- gdb_assert (kind <= TYPES_DOMAIN);
+ gdb_assert (kind <= MODULES_DOMAIN);

ourtype = types[kind];
ourtype2 = types2[kind];
@@ -4540,7 +4541,9 @@ search_symbols (const char *regexp, enum search_domain kind,
sym)))
|| (kind == TYPES_DOMAIN
&& SYMBOL_CLASS (sym) == LOC_TYPEDEF
- && SYMBOL_DOMAIN (sym) != MODULE_DOMAIN))))
+ && SYMBOL_DOMAIN (sym) != MODULE_DOMAIN)
+ || (kind == MODULES_DOMAIN
+ && SYMBOL_DOMAIN (sym) == MODULE_DOMAIN))))
{
/* match */
result.emplace_back (i, sym);
@@ -4671,6 +4674,11 @@ print_symbol_info (enum search_domain kind,

printf_filtered (";\n");
}
+ /* Printing of modules is currently done here, maybe at some future
+ point we might want a language specific method to print the module
+ symbol so that we can customise the output more. */
+ else if (kind == MODULES_DOMAIN)
+ printf_filtered ("%s\n", SYMBOL_PRINT_NAME (sym));
}

/* This help function for symtab_symbol_info() prints information
@@ -4711,11 +4719,11 @@ symtab_symbol_info (bool quiet, bool exclude_minsyms,
const char *t_regexp, int from_tty)
{
static const char * const classnames[] =
- {"variable", "function", "type"};
+ {"variable", "function", "type", "module"};
const char *last_filename = "";
int first = 1;

- gdb_assert (kind <= TYPES_DOMAIN);
+ gdb_assert (kind <= MODULES_DOMAIN);

if (regexp != nullptr && *regexp == '\0')
regexp = nullptr;
@@ -4934,6 +4942,22 @@ info_types_command_completer (struct cmd_list_element *ignore,
symbol_completer (ignore, tracker, text, word);
}

+/* Implement the 'info modules' command. */
+
+static void
+info_modules_command (const char *args, int from_tty)
+{
+ info_types_options opts;
+
+ auto grp = make_info_types_options_def_group (&opts);
+ gdb::option::process_options
+ (&args, gdb::option::PROCESS_OPTIONS_UNKNOWN_IS_OPERAND, grp);
+ if (args != nullptr && *args == '\0')
+ args = nullptr;
+ symtab_symbol_info (opts.quiet, true, args, MODULES_DOMAIN, NULL,
+ from_tty);
+}
+
/* Breakpoint all functions matching regular expression. */

void
@@ -6198,6 +6222,10 @@ Print information about all types matching REGEXP, or all types if no\n\
REGEXP is given. The optional flag -q disables printing of headers."));
set_cmd_completer_handle_brkchars (c, info_types_command_completer);

+ c = add_info ("modules", info_modules_command,
+ _("All module names, or those matching REGEXP."));
+ set_cmd_completer_handle_brkchars (c, info_types_command_completer);
+
add_info ("sources", info_sources_command,
_("Source files in the program."));

diff --git a/gdb/symtab.h b/gdb/symtab.h
index c4fd520e735..6e8bca0a86a 100644
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -799,8 +799,11 @@ enum search_domain
/* All defined types */
TYPES_DOMAIN = 2,

+ /* All modules. */
+ MODULES_DOMAIN = 3,
+
/* Any type. */
- ALL_DOMAIN = 3
+ ALL_DOMAIN = 4
};

extern const char *search_domain_name (enum search_domain);
diff --git a/gdb/testsuite/gdb.fortran/info-modules.exp b/gdb/testsuite/gdb.fortran/info-modules.exp
new file mode 100644
index 00000000000..33110236271
--- /dev/null
+++ b/gdb/testsuite/gdb.fortran/info-modules.exp
@@ -0,0 +1,61 @@
+# Copyright 2019 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 <http://www.gnu.org/licenses/>.
+
+# This file tests 'info modules'.
+
+load_lib "fortran.exp"
+
+if { [skip_fortran_tests] } { continue }
+
+standard_testfile info-types.f90
+
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile {debug f90}] } {
+ return -1
+}
+
+if { ![runto MAIN__] } {
+ perror "Could not run to breakpoint `MAIN__'."
+ continue
+}
+
+gdb_test "info modules" \
+ [multi_line \
+ "All defined modules:" \
+ "" \
+ "File .*:" \
+ "16:\[\t \]+mod1" \
+ "22:\[\t \]+mod2" ]
+
+gdb_test "info modules 1" \
+ [multi_line \
+ "All modules matching regular expression \"1\":" \
+ "" \
+ "File .*:" \
+ "16:\[\t \]+mod1" ]
+
+gdb_test "info modules 2" \
+ [multi_line \
+ "All modules matching regular expression \"2\":" \
+ "" \
+ "File .*:" \
+ "22:\[\t \]+mod2" ]
+
+gdb_test "info modules mod" \
+ [multi_line \
+ "All modules matching regular expression \"mod\":" \
+ "" \
+ "File .*:" \
+ "16:\[\t \]+mod1" \
+ "22:\[\t \]+mod2" ]
diff --git a/gdb/testsuite/gdb.fortran/info-types.exp b/gdb/testsuite/gdb.fortran/info-types.exp
index 81e67395e8a..b0656bce2b7 100644
--- a/gdb/testsuite/gdb.fortran/info-types.exp
+++ b/gdb/testsuite/gdb.fortran/info-types.exp
@@ -44,4 +44,4 @@ gdb_test "info types" \
"\[\t \]+${logical4}" \
"20:\[\t \]+Type __vtype_mod1_M1t1;" \
"17:\[\t \]+Type m1t1;" \
- "22:\[\t \]+Type s1;" ]
+ "26:\[\t \]+Type s1;" ]
diff --git a/gdb/testsuite/gdb.fortran/info-types.f90 b/gdb/testsuite/gdb.fortran/info-types.f90
index 0e27e1ddf08..859a9485c8f 100644
--- a/gdb/testsuite/gdb.fortran/info-types.f90
+++ b/gdb/testsuite/gdb.fortran/info-types.f90
@@ -19,8 +19,13 @@ module mod1
end type m1t1
end module mod1

+module mod2
+ integer :: mod2_var_1 = 123
+end module mod2
+
program info_types_test
use mod1
+ use mod2

type :: s1
integer :: a
--
2.14.5