From 51468b764689e7d724a87e6c2b8cdb4e599a3604 Mon Sep 17 00:00:00 2001 From: Kurtis Rader Date: Sun, 8 May 2016 15:57:56 -0700 Subject: add `function --shadow-builtin` flag It's currently too easy for someone to bork their shell by doing something like `function test; return 0; end`. That's obviously a silly, contrived, example but the point is that novice users who learn about functions are prone to do something like that without realizing it will bork the shell. Even expert users who know about the `test` builtin might forget that, say, `pwd` is a builtin. This change adds a `--shadow-builtin` flag that must be specified to indicate you know what you're doing. Fixes #3000 --- src/builtin.cpp | 55 ++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 44 insertions(+), 11 deletions(-) (limited to 'src/builtin.cpp') diff --git a/src/builtin.cpp b/src/builtin.cpp index e5261cb4..a79f898d 100644 --- a/src/builtin.cpp +++ b/src/builtin.cpp @@ -889,6 +889,7 @@ static int builtin_generic(parser_t &parser, io_streams_t &streams, wchar_t **ar } } } + return STATUS_BUILTIN_ERROR; } @@ -919,7 +920,11 @@ static wcstring functions_def(const wcstring &name) { out.append(esc_desc); } - if (!function_get_shadows(name)) { + if (function_get_shadow_builtin(name)) { + out.append(L" --shadow-builtin"); + } + + if (!function_get_shadow_scope(name)) { out.append(L" --no-scope-shadowing"); } @@ -1460,8 +1465,8 @@ static int builtin_pwd(parser_t &parser, io_streams_t &streams, wchar_t **argv) } /// Adds a function to the function set. It calls into function.cpp to perform any heavy lifting. -int define_function(parser_t &parser, io_streams_t &streams, const wcstring_list_t &c_args, - const wcstring &contents, int definition_line_offset, wcstring *out_err) { +int builtin_function(parser_t &parser, io_streams_t &streams, const wcstring_list_t &c_args, + const wcstring &contents, int definition_line_offset, wcstring *out_err) { wgetopter_t w; assert(out_err != NULL); @@ -1484,7 +1489,8 @@ int define_function(parser_t &parser, io_streams_t &streams, const wcstring_list wcstring_list_t named_arguments; wcstring_list_t inherit_vars; - bool shadows = true; + bool shadow_builtin = false; + bool shadow_scope = true; wcstring_list_t wrap_targets; @@ -1504,17 +1510,17 @@ int define_function(parser_t &parser, io_streams_t &streams, const wcstring_list {L"wraps", required_argument, 0, 'w'}, {L"help", no_argument, 0, 'h'}, {L"argument-names", no_argument, 0, 'a'}, + {L"shadow-builtin", no_argument, 0, 'B'}, {L"no-scope-shadowing", no_argument, 0, 'S'}, {L"inherit-variable", required_argument, 0, 'V'}, {0, 0, 0, 0}}; - while (1 && (!res)) { + while (1 && !res) { int opt_index = 0; // The leading - here specifies RETURN_IN_ORDER. - int opt = w.wgetopt_long(argc, argv, L"-d:s:j:p:v:e:w:haSV:", long_options, &opt_index); + int opt = w.wgetopt_long(argc, argv, L"-d:s:j:p:v:e:w:haBSV:", long_options, &opt_index); if (opt == -1) break; - switch (opt) { case 0: { if (long_options[opt_index].flag != 0) break; @@ -1536,7 +1542,6 @@ int define_function(parser_t &parser, io_streams_t &streams, const wcstring_list events.push_back(event_t::signal_event(sig)); break; } - case 'v': { if (wcsvarname(w.woptarg)) { append_format(*out_err, _(L"%ls: Invalid variable name '%ls'"), argv[0], @@ -1586,7 +1591,6 @@ int define_function(parser_t &parser, io_streams_t &streams, const wcstring_list e.type = EVENT_JOB_ID; e.param1.job_id = job_id; } - } else { errno = 0; pid = fish_wcstoi(w.woptarg, &end, 10); @@ -1611,8 +1615,12 @@ int define_function(parser_t &parser, io_streams_t &streams, const wcstring_list name_is_first_positional = !positionals.empty(); break; } + case 'B': { + shadow_builtin = true; + break; + } case 'S': { - shadows = 0; + shadow_scope = false; break; } case 'w': { @@ -1699,6 +1707,30 @@ int define_function(parser_t &parser, io_streams_t &streams, const wcstring_list } } + if (!res) { + bool function_name_shadows_builtin = false; + wcstring_list_t builtin_names = builtin_get_names(); + for (size_t i = 0; i < builtin_names.size(); i++) { + const wchar_t *el = builtin_names.at(i).c_str(); + if (el == function_name) { + function_name_shadows_builtin = true; + break; + } + } + if (function_name_shadows_builtin && !shadow_builtin) { + append_format( + *out_err, + _(L"%ls: function name shadows a builtin so you must use '--shadow-builtin'"), + argv[0]); + res = STATUS_BUILTIN_ERROR; + } else if (!function_name_shadows_builtin && shadow_builtin) { + append_format(*out_err, _(L"%ls: function name does not shadow a builtin so you " + L"must not use '--shadow-builtin'"), + argv[0]); + res = STATUS_BUILTIN_ERROR; + } + } + if (!res) { // Here we actually define the function! function_data_t d; @@ -1706,7 +1738,8 @@ int define_function(parser_t &parser, io_streams_t &streams, const wcstring_list d.name = function_name; if (desc) d.description = desc; d.events.swap(events); - d.shadows = shadows; + d.shadow_builtin = shadow_builtin; + d.shadow_scope = shadow_scope; d.named_arguments.swap(named_arguments); d.inherit_vars.swap(inherit_vars); -- cgit v1.2.3