From 295fef80bcc994bd668f369ad863ad8d12c962b7 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Wed, 3 Jun 2009 12:47:26 +0200 Subject: [PATCH] hush: add support for local builtin Signed-off-by: Denys Vlasenko --- shell/Config.in | 7 + shell/hush.c | 246 ++++++++++++++------ shell/hush_test/hush-misc/func_local1.right | 3 + shell/hush_test/hush-misc/func_local1.tests | 5 + shell/hush_test/hush-misc/func_local2.right | 14 ++ shell/hush_test/hush-misc/func_local2.tests | 7 + 6 files changed, 211 insertions(+), 71 deletions(-) create mode 100644 shell/hush_test/hush-misc/func_local1.right create mode 100755 shell/hush_test/hush-misc/func_local1.tests create mode 100644 shell/hush_test/hush-misc/func_local2.right create mode 100755 shell/hush_test/hush-misc/func_local2.tests diff --git a/shell/Config.in b/shell/Config.in index 57969f02c..ee56d89f3 100644 --- a/shell/Config.in +++ b/shell/Config.in @@ -232,6 +232,13 @@ config HUSH_FUNCTIONS help Enable support for shell functions in hush. +800 bytes. +config HUSH_LOCAL + bool "Support local builtin" + default n + depends on HUSH_FUNCTIONS + help + Enable support for local variables in functions. + config HUSH_EXPORT_N bool "Support export '-n' option" default n diff --git a/shell/hush.c b/shell/hush.c index e3f7b6eb7..1ad5fcd72 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -394,6 +394,9 @@ struct parse_context { struct variable { struct variable *next; char *varstr; /* points to "name=" portion */ +#if ENABLE_HUSH_LOCAL + unsigned func_nest_level; +#endif int max_len; /* if > 0, name is part of initial env; else name is malloced */ smallint flg_export; /* putenv should be done on this var */ smallint flg_read_only; @@ -488,6 +491,10 @@ struct globals { struct variable shell_ver; #if ENABLE_HUSH_FUNCTIONS struct function *top_func; +# if ENABLE_HUSH_LOCAL + struct variable **shadowed_vars_pp; + unsigned func_nest_level; +# endif #endif /* Signal and trap handling */ #if ENABLE_HUSH_FAST @@ -529,6 +536,9 @@ static int builtin_jobs(char **argv); #if ENABLE_HUSH_HELP static int builtin_help(char **argv); #endif +#if ENABLE_HUSH_LOCAL +static int builtin_local(char **argv); +#endif #if HUSH_DEBUG static int builtin_memleak(char **argv); #endif @@ -599,6 +609,9 @@ static const struct built_in_command bltins[] = { #if ENABLE_HUSH_JOB BLTIN("jobs" , builtin_jobs , "List active jobs"), #endif +#if ENABLE_HUSH_LOCAL + BLTIN("local" , builtin_local , "Set local variable"), +#endif #if HUSH_DEBUG BLTIN("memleak" , builtin_memleak , "Debug tool"), #endif @@ -1261,12 +1274,21 @@ static const char *get_local_var_value(const char *name) * -1: clear export flag and unsetenv the variable * flg_read_only is set only when we handle -R var=val */ -#if BB_MMU -#define set_local_var(str, flg_export, flg_read_only) \ +#if !BB_MMU && ENABLE_HUSH_LOCAL +/* all params are used */ +#elif BB_MMU && ENABLE_HUSH_LOCAL +#define set_local_var(str, flg_export, local_lvl, flg_read_only) \ + set_local_var(str, flg_export, local_lvl) +#elif BB_MMU && !ENABLE_HUSH_LOCAL +#define set_local_var(str, flg_export, local_lvl, flg_read_only) \ set_local_var(str, flg_export) +#elif !BB_MMU && !ENABLE_HUSH_LOCAL +#define set_local_var(str, flg_export, local_lvl, flg_read_only) \ + set_local_var(str, flg_export, flg_read_only) #endif -static int set_local_var(char *str, int flg_export, int flg_read_only) +static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only) { + struct variable **var_pp; struct variable *cur; char *eq_sign; int name_len; @@ -1278,15 +1300,10 @@ static int set_local_var(char *str, int flg_export, int flg_read_only) } name_len = eq_sign - str + 1; /* including '=' */ - cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */ - while (1) { + var_pp = &G.top_var; + while ((cur = *var_pp) != NULL) { if (strncmp(cur->varstr, str, name_len) != 0) { - if (!cur->next) { - /* Bail out. Note that now cur points - * to the last var in the linked list */ - break; - } - cur = cur->next; + var_pp = &cur->next; continue; } /* We found an existing var with this name */ @@ -1298,33 +1315,61 @@ static int set_local_var(char *str, int flg_export, int flg_read_only) free(str); return -1; } - if (flg_export == -1) { + if (flg_export == -1) { // "&& cur->flg_export" ? debug_printf_env("%s: unsetenv '%s'\n", __func__, str); *eq_sign = '\0'; unsetenv(str); *eq_sign = '='; } +#if ENABLE_HUSH_LOCAL + if (cur->func_nest_level < local_lvl) { + /* New variable is declared as local, + * and existing one is global, or local + * from enclosing function. + * Remove and save old one: */ + *var_pp = cur->next; + cur->next = *G.shadowed_vars_pp; + *G.shadowed_vars_pp = cur; + /* bash 3.2.33(1) and exported vars: + * # export z=z + * # f() { local z=a; env | grep ^z; } + * # f + * z=a + * # env | grep ^z + * z=z + */ + if (cur->flg_export) + flg_export = 1; + break; + } +#endif if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) { free_and_exp: free(str); goto exp; } - if (cur->max_len >= strlen(str)) { - /* This one is from startup env, reuse space */ - strcpy(cur->varstr, str); - goto free_and_exp; - } - /* max_len == 0 signifies "malloced" var, which we can - * (and has to) free */ - if (!cur->max_len) + if (cur->max_len != 0) { + if (cur->max_len >= strlen(str)) { + /* This one is from startup env, reuse space */ + strcpy(cur->varstr, str); + goto free_and_exp; + } + } else { + /* max_len == 0 signifies "malloced" var, which we can + * (and has to) free */ free(cur->varstr); + } cur->max_len = 0; goto set_str_and_exp; } - /* Not found - create next variable struct */ - cur->next = xzalloc(sizeof(*cur)); - cur = cur->next; + /* Not found - create new variable struct */ + cur = xzalloc(sizeof(*cur)); +#if ENABLE_HUSH_LOCAL + cur->func_nest_level = local_lvl; +#endif + cur->next = *var_pp; + *var_pp = cur; set_str_and_exp: cur->varstr = str; @@ -1418,7 +1463,7 @@ static void arith_set_local_var(const char *name, const char *val, int flags) { /* arith code doesnt malloc space, so do it for it */ char *var = xasprintf("%s=%s", name, val); - set_local_var(var, flags, 0); + set_local_var(var, flags, /*lvl:*/ 0, /*ro:*/ 0); } #endif @@ -1438,7 +1483,7 @@ static void add_vars(struct variable *var) debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr); putenv(var->varstr); } else { - debug_printf_env("%s: restoring local '%s'\n", __func__, var->varstr); + debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr); } var = next; } @@ -1471,7 +1516,7 @@ static struct variable *set_vars_and_save_old(char **strings) var_p->next = old; old = var_p; } - set_local_var(*s, 1, 0); + set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0); } s++; } @@ -2302,7 +2347,7 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) val = NULL; } else { char *new_var = xasprintf("%s=%s", var, val); - set_local_var(new_var, 0, 0); + set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0); } } } @@ -3036,9 +3081,13 @@ static int run_function(const struct function *funcp, char **argv) smallint sv_flg; save_and_replace_G_args(&sv, argv); + /* "we are in function, ok to use return" */ sv_flg = G.flag_return_in_progress; G.flag_return_in_progress = -1; +#if ENABLE_HUSH_LOCAL + G.func_nest_level++; +#endif /* On MMU, funcp->body is always non-NULL */ # if !BB_MMU @@ -3052,7 +3101,32 @@ static int run_function(const struct function *funcp, char **argv) rc = run_list(funcp->body); } +#if ENABLE_HUSH_LOCAL + { + struct variable *var; + struct variable **var_pp; + + var_pp = &G.top_var; + while ((var = *var_pp) != NULL) { + if (var->func_nest_level < G.func_nest_level) { + var_pp = &var->next; + continue; + } + /* Unexport */ + if (var->flg_export) + bb_unsetenv(var->varstr); + /* Remove from global list */ + *var_pp = var->next; + /* Free */ + if (!var->max_len) + free(var->varstr); + free(var); + } + G.func_nest_level--; + } +#endif G.flag_return_in_progress = sv_flg; + restore_G_args(&sv, argv); return rc; @@ -3606,7 +3680,7 @@ static int run_pipe(struct pipe *pi) p = expand_string_to_string(*argv); debug_printf_exec("set shell var:'%s'->'%s'\n", *argv, p); - set_local_var(p, 0, 0); + set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0); argv++; } /* Do we need to flag set_local_var() errors? @@ -3651,9 +3725,17 @@ static int run_pipe(struct pipe *pi) } #if ENABLE_HUSH_FUNCTIONS else { +# if ENABLE_HUSH_LOCAL + struct variable **sv; + sv = G.shadowed_vars_pp; + G.shadowed_vars_pp = &old_vars; +# endif debug_printf_exec(": function '%s' '%s'...\n", funcp->name, argv_expanded[1]); rcode = run_function(funcp, argv_expanded) & 0xff; +# if ENABLE_HUSH_LOCAL + G.shadowed_vars_pp = sv; +# endif } #endif } @@ -4050,7 +4132,7 @@ static int run_list(struct pipe *pi) } /* Insert next value from for_lcur */ /* note: *for_lcur already has quotes removed, $var expanded, etc */ - set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), 0, 0); + set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0); continue; } if (rword == RES_IN) { @@ -6250,7 +6332,7 @@ int hush_main(int argc, char **argv) break; case 'R': case 'V': - set_local_var(xstrdup(optarg), 0, opt == 'R'); + set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R'); break; # if ENABLE_HUSH_FUNCTIONS case 'F': { @@ -6583,6 +6665,55 @@ static void print_escaped(const char *s) } while (*s); } +#if !ENABLE_HUSH_LOCAL +#define helper_export_local(argv, exp, lvl) \ + helper_export_local(argv, exp) +#endif +static void helper_export_local(char **argv, int exp, int lvl) +{ + do { + char *name = *argv; + + /* So far we do not check that name is valid (TODO?) */ + + if (strchr(name, '=') == NULL) { + struct variable *var; + + var = get_local_var(name); + if (exp == -1) { /* unexporting? */ + /* export -n NAME (without =VALUE) */ + if (var) { + var->flg_export = 0; + debug_printf_env("%s: unsetenv '%s'\n", __func__, name); + unsetenv(name); + } /* else: export -n NOT_EXISTING_VAR: no-op */ + continue; + } + if (exp == 1) { /* exporting? */ + /* export NAME (without =VALUE) */ + if (var) { + var->flg_export = 1; + debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr); + putenv(var->varstr); + continue; + } + } + /* Exporting non-existing variable. + * bash does not put it in environment, + * but remembers that it is exported, + * and does put it in env when it is set later. + * We just set it to "" and export. */ + /* Or, it's "local NAME" (without =VALUE). + * bash sets the value to "". */ + name = xasprintf("%s=", name); + } else { + /* (Un)exporting/making local NAME=VALUE */ + name = xstrdup(name); + } + set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0); + } while (*++argv); +} + static int builtin_export(char **argv) { unsigned opt_unexport; @@ -6625,50 +6756,23 @@ static int builtin_export(char **argv) argv++; #endif - do { - char *name = *argv; - - /* So far we do not check that name is valid (TODO?) */ - - if (strchr(name, '=') == NULL) { - struct variable *var; - - var = get_local_var(name); - if (opt_unexport) { - /* export -n NAME (without =VALUE) */ - if (var) { - var->flg_export = 0; - debug_printf_env("%s: unsetenv '%s'\n", __func__, name); - unsetenv(name); - } /* else: export -n NOT_EXISTING_VAR: no-op */ - continue; - } - /* export NAME (without =VALUE) */ - if (var) { - var->flg_export = 1; - debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr); - putenv(var->varstr); - continue; - } - /* Exporting non-existing variable. - * bash does not put it in environment, - * but remembers that it is exported, - * and does put it in env when it is set later. - * We just set it to "" and export. */ - name = xasprintf("%s=", name); - } else { - /* (Un)exporting NAME=VALUE */ - name = xstrdup(name); - } - set_local_var(name, - /*export:*/ (opt_unexport ? -1 : 1), - /*readonly:*/ 0 - ); - } while (*++argv); + helper_export_local(argv, (opt_unexport ? -1 : 1), 0); return EXIT_SUCCESS; } +#if ENABLE_HUSH_LOCAL +static int builtin_local(char **argv) +{ + if (G.func_nest_level == 0) { + bb_error_msg("%s: not in a function", argv[0]); + return EXIT_FAILURE; /* bash compat */ + } + helper_export_local(argv, 0, G.func_nest_level); + return EXIT_SUCCESS; +} +#endif + static int builtin_trap(char **argv) { int sig; @@ -6944,7 +7048,7 @@ static int builtin_read(char **argv) //TODO: bash unbackslashes input, splits words and puts them in argv[i] string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL); - return set_local_var(string, 0, 0); + return set_local_var(string, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0); } /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set diff --git a/shell/hush_test/hush-misc/func_local1.right b/shell/hush_test/hush-misc/func_local1.right new file mode 100644 index 000000000..312178366 --- /dev/null +++ b/shell/hush_test/hush-misc/func_local1.right @@ -0,0 +1,3 @@ +z=a +z=z +Done diff --git a/shell/hush_test/hush-misc/func_local1.tests b/shell/hush_test/hush-misc/func_local1.tests new file mode 100755 index 000000000..1d594e20c --- /dev/null +++ b/shell/hush_test/hush-misc/func_local1.tests @@ -0,0 +1,5 @@ +export z=z +f() { local z=a; env | grep ^z; } +f +env | grep ^z +echo Done diff --git a/shell/hush_test/hush-misc/func_local2.right b/shell/hush_test/hush-misc/func_local2.right new file mode 100644 index 000000000..fe9343ac8 --- /dev/null +++ b/shell/hush_test/hush-misc/func_local2.right @@ -0,0 +1,14 @@ +1 +2 +1 +2 +1 +1 +2 +2 +3 +2 +2 +3 +1 +Done diff --git a/shell/hush_test/hush-misc/func_local2.tests b/shell/hush_test/hush-misc/func_local2.tests new file mode 100755 index 000000000..1a9ae559d --- /dev/null +++ b/shell/hush_test/hush-misc/func_local2.tests @@ -0,0 +1,7 @@ +x=1 +f() { echo $x; local x=$((x+1)); echo $x; } +g() { f; echo $x; f; local x=$((x+1)); f; echo $x; f; } +f +g +echo $x +echo Done