[PATCH v2 1/1] gdb: Introduce new setting to filter out shadowed variables.
Stephan Rohr <[email protected]>
| Newsgroups | gmane.comp.gdb.patches |
|---|---|
| Message-ID | <[email protected]> |
From: "Sargsyan, Eduard" <[email protected]> Add a new setting 'print shadowed on|off' to control the printing of shadowed variables in 'info locals'. Add a new option '-shadowed on|off' to overwrite this setting for the invocation of the command. When shadowed variables are present, each variable involved in a shadowing relationship is annotated with its declaration location '<file:line>'; the ones hidden by an inner declaration are additionally marked ', shadowed'. Given this code, stopped at line 10: 1 int num = 1; 2 int 3 main () 4 { 5 const char *str = "main"; 6 int num = 3; 7 { 8 const char *str = "nested"; 9 int num = 5; 10 num = 0; // break here 11 } 12 return num; 13 } By default, 'info locals' prints shadowed variables: (gdb) info locals str = 0x555555556009 "nested" <main.c:8> num = 5 <main.c:9> str = 0x555555556004 "main" <main.c:5, shadowed> num = 3 <main.c:6, shadowed> Use 'set print shadowed off' to hide shadowed variables. The user may not want to print shadowed variables: (gdb) set print shadowed off (gdb) info locals str = 0x555555556009 "nested" num = 5 Some shadowed variables were omitted, use 'set print shadowed on' to include them. Co-Authored-By: Stephan Rohr <[email protected]> --- gdb/NEWS | 14 +++ gdb/doc/gdb.texinfo | 22 +++- gdb/stack.c | 143 +++++++++++++++++++---- gdb/testsuite/gdb.ada/var_shadowing.exp | 1 + gdb/testsuite/gdb.base/options.exp | 23 ++++ gdb/testsuite/gdb.base/var-shadowing.c | 2 +- gdb/testsuite/gdb.base/var-shadowing.exp | 81 +++++++++++++ 7 files changed, 263 insertions(+), 23 deletions(-) diff --git a/gdb/NEWS b/gdb/NEWS index 10c182067f9..3a1799143a6 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -3,6 +3,20 @@ *** Changes since GDB 18 +* New commands + +set print shadowed on|off +show print shadowed +This controls the output of the "info locals" command. If the option is 'off' +shadowed variables will be omitted in output. The default is to print +shadowed variables. + +* Changed commands + +info locals + The new "-shadowed on|off" option overrides the "set print shadowed" + setting for a single invocation of the command. + *** Changes in GDB 18 * Support for the Common Trace Format (CTF) has been removed. GDB now diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 0030698dcee..502d92c6b1d 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -9178,7 +9178,7 @@ If both @var{regexp} and @var{type_regexp} are provided, an argument is printed only if its name matches @var{regexp} and its type matches @var{type_regexp}. -@item info locals [-q] +@item info locals [-q] [-shadowed [@code{on}|@code{off}]] @kindex info locals Print the local variables of the selected frame, each on a separate line. These are all variables (declared either static or automatic) @@ -9188,6 +9188,9 @@ The optional flag @samp{-q}, which stands for @samp{quiet}, disables printing header information and messages explaining why no local variables have been printed. +The optional flag @samp{-shadowed} overrides the @code{set print shadowed} +setting (@pxref{set print shadowed}) for this invocation of the command. + @smallexample @group 1: int x = 3; @@ -9202,6 +9205,7 @@ have been printed. x = 4 <file.c:3> y = 52 x = 3 <file.c:1, shadowed> +Use 'set print shadowed off' to hide shadowed variables. @end group @end smallexample @@ -9212,7 +9216,8 @@ same name which is declared within an inner scope (decision block, method, or inner class). When shadowing is detected, location information is added to all instances of the shadowed variable name. The outermost instances are additionally followed by @samp{shadowed} -to indicate that they are not the active variable. +to indicate that they are not the active variable. Printing shadowed +variables can be controlled by @ref{set print shadowed}. @item info locals [-q] [-t @var{type_regexp}] [@var{regexp}] Like @kbd{info locals}, but only print the local variables selected @@ -12829,6 +12834,19 @@ Do not pretty print C@t{++} virtual function tables. @item show print vtbl Show whether C@t{++} virtual function tables are pretty printed, or not. + +@anchor{set print shadowed} +@item set print shadowed +@itemx set print shadowed on +@cindex printing shadowed variables +Print variables that are shadowed by a declaration in an inner scope +(@pxref{shadowed variables}). The default is on. + +@item set print shadowed off +Do not print shadowed variables. + +@item show print shadowed +Show whether shadowed variables are printed or not. @end table @node Pretty Printing diff --git a/gdb/stack.c b/gdb/stack.c index 954ef6b11a4..56f3d7d599b 100644 --- a/gdb/stack.c +++ b/gdb/stack.c @@ -217,10 +217,45 @@ static const gdb::option::option_def backtrace_command_option_defs[] = { }, }; +/* Option for printing shadowed variables. */ + +struct shadowed_print_options +{ + bool print_shadowed = true; +}; + +static shadowed_print_options user_shadowed_print_options; + +/* Implement "show print shadowed". */ + +static void +show_print_shadowed (struct ui_file *file, int from_tty, + struct cmd_list_element *c, const char *value) +{ + gdb_printf (file, _("Printing of shadowed variables is %s.\n"), value); +} + +/* Option definitions for the shadowed variables setting. */ + +static const gdb::option::option_def shadowed_print_option_defs[] = { + + gdb::option::boolean_option_def<shadowed_print_options> { + "shadowed", + [] (shadowed_print_options *opt) { return &opt->print_shadowed; }, + show_print_shadowed, /* show_cmd_cb */ + N_("Set printing of shadowed variables."), + N_("Show printing of shadowed variables."), + N_("When on, variables that are shadowed by a declaration in an inner\n\ +scope are printed, annotated with the location of their declaration.\n\ +When off, such variables are omitted."), + }, +}; + /* Prototypes for local functions. */ static void print_frame_local_vars (const frame_info_ptr &frame, - bool quiet, + const shadowed_print_options &sh_opts, + bool quiet, bool print_shadowed_msg, const char *regexp, const char *t_regexp, int num_tabs, struct ui_file *stream); @@ -1985,7 +2020,8 @@ backtrace_command_1 (const frame_print_options &fp_opts, print_frame_info (fp_opts, fi, 1, LOCATION, 1, 0); if ((flags & PRINT_LOCALS) != 0) - print_frame_local_vars (fi, false, NULL, NULL, 1, gdb_stdout); + print_frame_local_vars (fi, user_shadowed_print_options, false, + false, NULL, NULL, 1, gdb_stdout); /* Save the last frame to check for error conditions. */ trailing = fi; @@ -2258,6 +2294,9 @@ struct print_variable_and_value_data int num_tabs; struct ui_file *stream; int values_printed; + bool print_shadowed = true; + bool printed_shadowed_variables = false; + bool omitted_shadowed_variables = false; void operator() (const char *print_name, struct symbol *sym, var_shadowing shadow_status); @@ -2281,6 +2320,12 @@ print_variable_and_value_data::operator() (const char *print_name, if (language_def (sym->language ())->symbol_printing_suppressed (sym)) return; + if (!print_shadowed && shadow_status == var_shadowing::SHADOWED) + { + omitted_shadowed_variables = true; + return; + } + frame = frame_find_by_id (frame_id); if (frame == NULL) { @@ -2289,9 +2334,13 @@ print_variable_and_value_data::operator() (const char *print_name, } print_variable_and_value (print_name, sym, frame, stream, num_tabs, - shadow_status); + print_shadowed ? shadow_status + : var_shadowing::NONE); values_printed = 1; + + if (shadow_status == var_shadowing::SHADOWED) + printed_shadowed_variables = true; } /* Prepares the regular expression REG from REGEXP. @@ -2312,6 +2361,9 @@ prepare_reg (const char *regexp, std::optional<compiled_regex> *reg) /* Print all variables from the innermost up to the function block of FRAME. Print them with values to STREAM indented by NUM_TABS. + SH_OPTS controls whether shadowed variables are printed. + PRINT_SHADOWED_MSG controls whether a trailing "set print shadowed" message + is printed. If REGEXP is not NULL, only print local variables whose name matches REGEXP. If T_REGEXP is not NULL, only print local variables whose type @@ -2321,7 +2373,8 @@ prepare_reg (const char *regexp, std::optional<compiled_regex> *reg) static void print_frame_local_vars (const frame_info_ptr &frame, - bool quiet, + const shadowed_print_options &sh_opts, + bool quiet, bool print_shadowed_msg, const char *regexp, const char *t_regexp, int num_tabs, struct ui_file *stream) { @@ -2351,6 +2404,7 @@ print_frame_local_vars (const frame_info_ptr &frame, cb_data.num_tabs = 4 * num_tabs; cb_data.stream = stream; cb_data.values_printed = 0; + cb_data.print_shadowed = sh_opts.print_shadowed; /* Temporarily change the selected frame to the given FRAME. This allows routines that rely on the selected frame instead @@ -2360,13 +2414,28 @@ print_frame_local_vars (const frame_info_ptr &frame, iterate_over_block_local_vars_printing (block, cb_data); - if (!cb_data.values_printed && !quiet) + if (quiet) + return; + + if (!cb_data.values_printed) { if (regexp == NULL && t_regexp == NULL) gdb_printf (stream, _("No locals.\n")); else gdb_printf (stream, _("No matching locals.\n")); } + + if (!print_shadowed_msg) + return; + + if (cb_data.printed_shadowed_variables) + gdb_printf (stream, + _("Use 'set print shadowed off' " + "to hide shadowed variables.\n")); + else if (cb_data.omitted_shadowed_variables) + gdb_printf (stream, + _("Some shadowed variables were omitted, use " + "'set print shadowed on' to include them.\n")); } /* Structure to hold the values of the options used by the 'info @@ -2397,24 +2466,51 @@ static const gdb::option::option_def info_print_options_defs[] = { } }; -/* Returns the option group used by 'info locals' and 'info args' - commands. */ +/* Returns the option group used by the 'info args' command. */ static gdb::option::option_def_group -make_info_print_options_def_group (info_print_options *opts) +make_info_args_options_def_group (info_print_options *opts) { return {{info_print_options_defs}, opts}; } -/* Command completer for 'info locals' and 'info args'. */ +/* Returns the option groups used by the 'info locals' command. */ + +static std::array<gdb::option::option_def_group, 2> +make_info_locals_options_def_group (info_print_options *opts, + shadowed_print_options *sh_opts) +{ + return {{ + { {info_print_options_defs}, opts }, + { {shadowed_print_option_defs}, sh_opts } + }}; +} + +/* Command completer for 'info args'. */ static void -info_print_command_completer (struct cmd_list_element *ignore, - completion_tracker &tracker, - const char *text, const char * /* word */) +info_args_command_completer (struct cmd_list_element *ignore, + completion_tracker &tracker, + const char *text, const char * /* word */) { const auto group - = make_info_print_options_def_group (nullptr); + = make_info_args_options_def_group (nullptr); + if (gdb::option::complete_options + (tracker, &text, gdb::option::PROCESS_OPTIONS_UNKNOWN_IS_OPERAND, group)) + return; + + const char *word = advance_to_expression_complete_word_point (tracker, text); + symbol_completer (ignore, tracker, text, word); +} + +/* Command completer for 'info locals'. */ + +static void +info_locals_command_completer (struct cmd_list_element *ignore, + completion_tracker &tracker, + const char *text, const char * /* word */) +{ + const auto group = make_info_locals_options_def_group (nullptr, nullptr); if (gdb::option::complete_options (tracker, &text, gdb::option::PROCESS_OPTIONS_UNKNOWN_IS_OPERAND, group)) return; @@ -2429,7 +2525,8 @@ void info_locals_command (const char *args, int from_tty) { info_print_options opts; - auto grp = make_info_print_options_def_group (&opts); + shadowed_print_options sh_opts = user_shadowed_print_options; + auto grp = make_info_locals_options_def_group (&opts, &sh_opts); gdb::option::process_options (&args, gdb::option::PROCESS_OPTIONS_UNKNOWN_IS_OPERAND, grp); if (args != nullptr && *args == '\0') @@ -2437,7 +2534,7 @@ info_locals_command (const char *args, int from_tty) print_frame_local_vars (get_selected_frame (_("No frame selected.")), - opts.quiet, args, + sh_opts, opts.quiet, true, args, opts.type_regexp.empty () ? nullptr : opts.type_regexp.c_str (), 0, gdb_stdout); } @@ -2546,7 +2643,7 @@ void info_args_command (const char *args, int from_tty) { info_print_options opts; - auto grp = make_info_print_options_def_group (&opts); + auto grp = make_info_args_options_def_group (&opts); gdb::option::process_options (&args, gdb::option::PROCESS_OPTIONS_UNKNOWN_IS_OPERAND, grp); if (args != nullptr && *args == '\0') @@ -3508,11 +3605,13 @@ Usage: info frame level LEVEL"), cmd = add_info ("locals", info_locals_command, info_print_args_help (_("\ All local variables of current stack frame or those matching REGEXPs.\n\ -Usage: info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]\n\ -Prints the local variables of the current stack frame.\n"), +Usage: info locals [-q] [-shadowed [on|off]] [-t TYPEREGEXP] [NAMEREGEXP]\n\ +Prints the local variables of the current stack frame.\n\ +The -shadowed option overrides the \"set print shadowed\" setting for this\n\ +command.\n"), _("local variables"), false)); - set_cmd_completer_handle_brkchars (cmd, info_print_command_completer); + set_cmd_completer_handle_brkchars (cmd, info_locals_command_completer); cmd = add_info ("args", info_args_command, info_print_args_help (_("\ All argument variables of current stack frame or those matching REGEXPs.\n\ @@ -3520,7 +3619,7 @@ Usage: info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]\n\ Prints the argument variables of the current stack frame.\n"), _("argument variables"), false)); - set_cmd_completer_handle_brkchars (cmd, info_print_command_completer); + set_cmd_completer_handle_brkchars (cmd, info_args_command_completer); /* Install "set print raw frame-arguments", a deprecated spelling of "set print raw-frame-arguments". */ @@ -3560,4 +3659,8 @@ source line."), gdb::option::add_setshow_cmds_for_options (class_stack, &user_frame_print_options, frame_print_option_defs, &setprintlist, &showprintlist); + + gdb::option::add_setshow_cmds_for_options + (class_support, &user_shadowed_print_options, + shadowed_print_option_defs, &setprintlist, &showprintlist); } diff --git a/gdb/testsuite/gdb.ada/var_shadowing.exp b/gdb/testsuite/gdb.ada/var_shadowing.exp index ffa96b049cf..d927b0d9888 100644 --- a/gdb/testsuite/gdb.ada/var_shadowing.exp +++ b/gdb/testsuite/gdb.ada/var_shadowing.exp @@ -36,4 +36,5 @@ gdb_test "info locals" [multi_line \ "i = 111\t<$testfile.adb:$i_level3>" \ "i = 11\t<$testfile.adb:$i_level2, shadowed>" \ "i = 1\t<$testfile.adb:$i_level1, shadowed>" \ + "Use 'set print shadowed off' to hide shadowed variables." \ ] "info locals at innermost level" diff --git a/gdb/testsuite/gdb.base/options.exp b/gdb/testsuite/gdb.base/options.exp index 35487ead6a7..aa4293f1016 100644 --- a/gdb/testsuite/gdb.base/options.exp +++ b/gdb/testsuite/gdb.base/options.exp @@ -30,6 +30,7 @@ # - tfaas # - thread apply # - taas +# - info locals load_lib compile-support.exp load_lib completion-support.exp @@ -531,6 +532,25 @@ proc_with_prefix test-info-threads {} { test_gdb_complete_none "info threads I" } +# Basic option-machinery + "info locals" command integration tests. +proc_with_prefix test-info-locals {} { + clean_restart $::testfile + + if {![runto_main]} { + return + } + + test_gdb_complete_multiple "info locals " "-" "" { + "-q" + "-shadowed" + "-t" + } + + test_gdb_complete_unique \ + "info locals -s" \ + "info locals -shadowed" +} + # Miscellaneous tests. proc_with_prefix test-misc {variant} { global all_options @@ -1175,6 +1195,9 @@ test-thread-apply # Basic "info threads" integration tests. test-info-threads +# Basic "info locals" integration tests. +test-info-locals + # There was a bug where the "metasyntactic variable" was glued to the # option. gdb_test "help maintenance test-options unknown-is-operand" \ diff --git a/gdb/testsuite/gdb.base/var-shadowing.c b/gdb/testsuite/gdb.base/var-shadowing.c index 7886ea31aec..a3ab8d9bb01 100644 --- a/gdb/testsuite/gdb.base/var-shadowing.c +++ b/gdb/testsuite/gdb.base/var-shadowing.c @@ -24,7 +24,7 @@ shadowing (void) a = 101; /* bp for locals 1 */ { unsigned int val2 = 3; /* val2-d2 */ - unsigned int val3 = 4; /* val3-d1 */ + double val3 = 4; /* val3-d1 */ a = 102; /* bp for locals 2 */ { unsigned int val1 = 5; /* val1-d2 */ diff --git a/gdb/testsuite/gdb.base/var-shadowing.exp b/gdb/testsuite/gdb.base/var-shadowing.exp index 502cbad11f6..8efbabadd0c 100644 --- a/gdb/testsuite/gdb.base/var-shadowing.exp +++ b/gdb/testsuite/gdb.base/var-shadowing.exp @@ -54,6 +54,7 @@ gdb_test "info locals" [multi_line \ "a = 101" \ "val1 = 1" \ "val2 = 2\t<$srcfile:$val2_d1, shadowed>" \ + "Use 'set print shadowed off' to hide shadowed variables." \ ] "info locals first level" gdb_breakpoint $srcfile:$bp_line3 @@ -65,6 +66,7 @@ gdb_test "info locals" [multi_line \ "a = 102" \ "val1 = 1\t<$srcfile:$val1_d1, shadowed>" \ "val2 = 2\t<$srcfile:$val2_d1, shadowed>" \ + "Use 'set print shadowed off' to hide shadowed variables." \ ] "info locals second level" gdb_breakpoint $srcfile:$bp_line4 @@ -80,8 +82,87 @@ gdb_test "info locals" [multi_line \ "a = 103\t<$srcfile:$a_line, shadowed>" \ "val1 = 1\t<$srcfile:$val1_d1, shadowed>" \ "val2 = 2\t<$srcfile:$val2_d1, shadowed>" \ + "Use 'set print shadowed off' to hide shadowed variables." \ ] "info locals at innermost level" +gdb_test "info locals -shadowed off" [multi_line \ + "a = 999" \ + "val1 = 6" \ + "val2 = 7" \ + "val3 = 8" \ + "Some shadowed variables were omitted, use 'set print shadowed on' to include them." \ + ] "info locals -shadowed off at innermost level" + +# 'val3' is declared as a 'double' in the outer scope only, so a type filter +# selects the shadowed variable only. +gdb_test "info locals -t double" [multi_line \ + "val3 = 4\t<$srcfile:$val3_d1, shadowed>" \ + "Use 'set print shadowed off' to hide shadowed variables." \ + ] "info locals -t double at innermost level" + +# Ensure 'backtrace -full' does not print the shadowed variables hint. +gdb_test "backtrace -full" [multi_line \ + "#0 +shadowing \\(\\) at .*" \ + "\[ \t\]+a = 999\t<${testfile}2.c:16>" \ + "\[ \t\]+val1 = 6\t<$srcfile:$val1_d3>" \ + "\[ \t\]+val2 = 7\t<$srcfile:$val2_d3>" \ + "\[ \t\]+val3 = 8\t<$srcfile:$val3_d2>" \ + "\[ \t\]+val1 = 5\t<$srcfile:$val1_d2, shadowed>" \ + "\[ \t\]+val2 = 3\t<$srcfile:$val2_d2, shadowed>" \ + "\[ \t\]+val3 = 4\t<$srcfile:$val3_d1, shadowed>" \ + "\[ \t\]+a = 103\t<$srcfile:$a_line, shadowed>" \ + "\[ \t\]+val1 = 1\t<$srcfile:$val1_d1, shadowed>" \ + "\[ \t\]+val2 = 2\t<$srcfile:$val2_d1, shadowed>" \ + "#1 +$hex in main \\(\\) at .*" \ + "No locals\\." \ + ] "bt -full at innermost level" + +gdb_test_no_output "set print shadowed off" + +gdb_test "show print shadowed" \ + "Printing of shadowed variables is off\\." \ + "show print shadowed off" + +gdb_test "info locals" [multi_line \ + "a = 999" \ + "val1 = 6" \ + "val2 = 7" \ + "val3 = 8" \ + "Some shadowed variables were omitted, use 'set print shadowed on' to include them." \ + ] "info locals at innermost level with filtered out shadowed" + +# Only the shadowed 'val3' matches the type filter, so nothing is printed. +# Still, the user is told that variables were omitted due to shadowing. +gdb_test "info locals -t double" [multi_line \ + "No matching locals\\." \ + "Some shadowed variables were omitted, use 'set print shadowed on' to include them." \ + ] "info locals -t double with filtered out shadowed" + +# A variable filtered out by a regexp is not reported as omitted due to +# shadowing. +gdb_test "info locals -t float" "No matching locals\\." \ + "info locals -t float with filtered out shadowed" + +# The '-shadowed' option overrides the setting for one invocation. +gdb_test "info locals -shadowed on" [multi_line \ + "a = 999\t<${testfile}2.c:16>" \ + "val1 = 6\t<$srcfile:$val1_d3>" \ + "val2 = 7\t<$srcfile:$val2_d3>" \ + "val3 = 8\t<$srcfile:$val3_d2>" \ + "val1 = 5\t<$srcfile:$val1_d2, shadowed>" \ + "val2 = 3\t<$srcfile:$val2_d2, shadowed>" \ + "val3 = 4\t<$srcfile:$val3_d1, shadowed>" \ + "a = 103\t<$srcfile:$a_line, shadowed>" \ + "val1 = 1\t<$srcfile:$val1_d1, shadowed>" \ + "val2 = 2\t<$srcfile:$val2_d1, shadowed>" \ + "Use 'set print shadowed off' to hide shadowed variables." \ + ] "info locals -shadowed on at innermost level" + +# '-q' suppresses the hint about the setting. +gdb_test_no_output "info locals -q -t double" + +gdb_test_no_output "set print shadowed on" + gdb_breakpoint $srcfile:$bp_line5 gdb_continue_to_breakpoint "continue to outermost level last" \ ".*$srcfile:$bp_line5.*" -- 2.43.0 ________________________________________ Intel Deutschland GmbH Registered Address: Dornacher Strasse 1, 85622 Feldkirchen, Germany Tel: +49 (89) 99143-0 www.intel.de Managing Directors: Candice Moore, Jeffrey Schneiderman, Ramachandran Sitaraman Chairperson of the Supervisory Board: Sonja Pierer Registered Seat: Munich Commercial Register B: Amtsgericht Munich HRB 186928 This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). 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