diff options
Diffstat (limited to 'src/ex_eval.c')
-rw-r--r-- | src/ex_eval.c | 2004 |
1 files changed, 2004 insertions, 0 deletions
diff --git a/src/ex_eval.c b/src/ex_eval.c new file mode 100644 index 0000000000..921d608670 --- /dev/null +++ b/src/ex_eval.c @@ -0,0 +1,2004 @@ +/* vi:set ts=8 sts=4 sw=4: + * + * VIM - Vi IMproved by Bram Moolenaar + * + * Do ":help uganda" in Vim to read copying and usage conditions. + * Do ":help credits" in Vim to see a list of people who contributed. + * See README.txt for an overview of the Vim source code. + */ + +/* + * ex_eval.c: functions for Ex command line for the +eval feature. + */ + +#include "vim.h" + +#if defined(FEAT_EVAL) || defined(PROTO) + +static void free_msglist __ARGS((struct msglist *l)); +static int throw_exception __ARGS((void *, int, char_u *)); +static void rewind_conditionals __ARGS((struct condstack *, + int, int, int *)); + +/* + * Exception handling terms: + * + * :try ":try" command \ + * ... try block | + * :catch RE ":catch" command | + * ... catch clause |- try conditional + * :finally ":finally" command | + * ... finally clause | + * :endtry ":endtry" command / + * + * The try conditional may have any number of catch clauses and at most one + * finally clause. A ":throw" command can be inside the try block, a catch + * clause, the finally clause, or in a function called or script sourced from + * there or even outside the try conditional. Try conditionals may be nested. + */ + +/* + * Configuration whether an exception is thrown on error or interrupt. When + * the preprocessor macros below evaluate to FALSE, an error (did_emsg) or + * interrupt (got_int) under an active try conditional terminates the script + * after the non-active finally clauses of all active try conditionals have been + * executed. Otherwise, errors and/or interrupts are converted into catchable + * exceptions (did_throw additionally set), which terminate the script only if + * not caught. For user exceptions, only did_throw is set. (Note: got_int can + * be set asyncronously afterwards by a SIGINT, so did_throw && got_int is not + * a reliant test that the exception currently being thrown is an interrupt + * exception. Similarly, did_emsg can be set afterwards on an error in an + * (unskipped) conditional command inside an inactive conditional, so did_throw + * && did_emsg is not a reliant test that the exception currently being thrown + * is an error exception.) - The macros can be defined as expressions checking + * for a variable that is allowed to be changed during execution of a script. + */ +#if 0 +/* Expressions used for testing during the development phase. */ +# define THROW_ON_ERROR (!eval_to_number("$VIMNOERRTHROW")) +# define THROW_ON_INTERRUPT (!eval_to_number("$VIMNOINTTHROW")) +# define THROW_TEST +#else +/* Values used for the Vim release. */ +# define THROW_ON_ERROR TRUE +# define THROW_ON_INTERRUPT TRUE +#endif + +static void catch_exception __ARGS((except_T *excp)); +static void finish_exception __ARGS((except_T *excp)); +static void discard_exception __ARGS((except_T *excp, int was_finished)); +static void report_pending __ARGS((int action, int pending, void *value)); + +/* + * When several errors appear in a row, setting "force_abort" is delayed until + * the failing command returned. "cause_abort" is set to TRUE meanwhile, in + * order to indicate that situation. This is useful when "force_abort" was set + * during execution of a function call from an expression: the aborting of the + * expression evaluation is done without producing any error messages, but all + * error messages on parsing errors during the expression evaluation are given + * (even if a try conditional is active). + */ +static int cause_abort = FALSE; + +/* + * Return TRUE when immdediately aborting on error, or when an interrupt + * occurred or an exception was thrown but not caught. Use for ":{range}call" + * to check whether an aborted function that does not handle a range itself + * should be called again for the next line in the range. Also used for + * cancelling expression evaluation after a function call caused an immediate + * abort. Note that the first emsg() call temporarily resets "force_abort" + * until the throw point for error messages has been reached. That is, during + * cancellation of an expression evaluation after an aborting function call or + * due to a parsing error, aborting() always returns the same value. + */ + int +aborting() +{ + return (did_emsg && force_abort) || got_int || did_throw; +} + +/* + * The value of "force_abort" is temporarily reset by the first emsg() call + * during an expression evaluation, and "cause_abort" is used instead. It might + * be necessary to restore "force_abort" even before the throw point for the + * error message has been reached. update_force_abort() should be called then. + */ + void +update_force_abort() +{ + if (cause_abort) + force_abort = TRUE; +} + +/* + * Return TRUE if a command with a subcommand resulting in "retcode" should + * abort the script processing. Can be used to suppress an autocommand after + * execution of a failing subcommand as long as the error message has not been + * displayed and actually caused the abortion. + */ + int +should_abort(retcode) + int retcode; +{ + return ((retcode == FAIL && trylevel != 0 && !emsg_silent) || aborting()); +} + +/* + * Return TRUE if a function with the "abort" flag should not be considered + * ended on an error. This means that parsing commands is continued in order + * to find finally clauses to be executed, and that some errors in skipped + * commands are still reported. + */ + int +aborted_in_try() +{ + /* This function is only called after an error. In this case, "force_abort" + * determines whether searching for finally clauses is necessary. */ + return force_abort; +} + +/* + * cause_errthrow(): Cause a throw of an error exception if appropriate. + * Return TRUE if the error message should not be displayed by emsg(). + * Sets "ignore", if the emsg() call should be ignored completely. + * + * When several messages appear in the same command, the first is usually the + * most specific one and used as the exception value. The "severe" flag can be + * set to TRUE, if a later but severer message should be used instead. + */ + int +cause_errthrow(mesg, severe, ignore) + char_u *mesg; + int severe; + int *ignore; +{ + struct msglist *elem; + struct msglist **plist; + + /* + * Do nothing when displaying the interrupt message or reporting an uncaught + * exception (which has already been discarded then) at the top level. Also + * when no exception can be thrown. The message will be displayed by + * emsg(). + */ + if (suppress_errthrow) + return FALSE; + + /* + * If emsg() has not been called previously, temporarily reset "force_abort" + * until the throw point for error messages has been reached. This ensures + * that aborting() returns the same value for all errors that appear in the + * same command. This means particularly that for parsing errors during + * expression evaluation emsg() will be called multiply, even when the + * expression is evaluated from a finally clause that was activated due to + * an aborting error, interrupt, or exception. + */ + if (!did_emsg) + { + cause_abort = force_abort; + force_abort = FALSE; + } + + /* + * If no try conditional is active and no exception is being thrown and + * there has not been an error in a try conditional or a throw so far, do + * nothing (for compatibility of non-EH scripts). The message will then be + * displayed by emsg(). When ":silent!" was used and we are not currently + * throwing an exception, do nothing. The message text will then be stored + * to v:errmsg by emsg() without displaying it. + */ + if (((trylevel == 0 && !cause_abort) || emsg_silent) && !did_throw) + return FALSE; + + /* + * Ignore an interrupt message when inside a try conditional or when an + * exception is being thrown or when an error in a try conditional or throw + * has been detected previously. This is important in order that an + * interrupt exception is catchable by the innermost try conditional and + * not replaced by an interrupt message error exception. + */ + if (mesg == (char_u *)_(e_interr)) + { + *ignore = TRUE; + return TRUE; + } + + /* + * Ensure that all commands in nested function calls and sourced files + * are aborted immediately. + */ + cause_abort = TRUE; + + /* + * When an exception is being thrown, some commands (like conditionals) are + * not skipped. Errors in those commands may affect what of the subsequent + * commands are regarded part of catch and finally clauses. Catching the + * exception would then cause execution of commands not intended by the + * user, who wouldn't even get aware of the problem. Therefor, discard the + * exception currently being thrown to prevent it from being caught. Just + * execute finally clauses and terminate. + */ + if (did_throw) + { + /* When discarding an interrupt exception, reset got_int to prevent the + * same interrupt being converted to an exception again and discarding + * the error exception we are about to throw here. */ + if (current_exception->type == ET_INTERRUPT) + got_int = FALSE; + discard_current_exception(); + } + +#ifdef THROW_TEST + if (!THROW_ON_ERROR) + { + /* + * Print error message immediately without searching for a matching + * catch clause; just finally clauses are executed before the script + * is terminated. + */ + return FALSE; + } + else +#endif + { + /* + * Prepare the throw of an error exception, so that everything will + * be aborted (except for executing finally clauses), until the error + * exception is caught; if still uncaught at the top level, the error + * message will be displayed and the script processing terminated + * then. - This function has no access to the conditional stack. + * Thus, the actual throw is made after the failing command has + * returned. - Throw only the first of several errors in a row, except + * a severe error is following. + */ + if (msg_list != NULL) + { + plist = msg_list; + while (*plist != NULL) + plist = &(*plist)->next; + + elem = (struct msglist *)alloc((unsigned)sizeof(struct msglist)); + if (elem == NULL) + { + suppress_errthrow = TRUE; + EMSG(_(e_outofmem)); + } + else + { + elem->msg = vim_strsave(mesg); + if (elem->msg == NULL) + { + vim_free(elem); + suppress_errthrow = TRUE; + EMSG(_(e_outofmem)); + } + else + { + elem->next = NULL; + elem->throw_msg = NULL; + *plist = elem; + if (plist == msg_list || severe) + { + char_u *tmsg; + + /* Skip the extra "Vim " prefix for message "E458". */ + tmsg = elem->msg; + if (STRNCMP(tmsg, "Vim E", 5) == 0 + && VIM_ISDIGIT(tmsg[5]) + && VIM_ISDIGIT(tmsg[6]) + && VIM_ISDIGIT(tmsg[7]) + && tmsg[8] == ':' + && tmsg[9] == ' ') + (*msg_list)->throw_msg = &tmsg[4]; + else + (*msg_list)->throw_msg = tmsg; + } + } + } + } + return TRUE; + } +} + +/* + * Free a "msg_list" and the messages it contains. + */ + static void +free_msglist(l) + struct msglist *l; +{ + struct msglist *messages, *next; + + messages = l; + while (messages != NULL) + { + next = messages->next; + vim_free(messages->msg); + vim_free(messages); + messages = next; + } +} + +/* + * Throw the message specified in the call to cause_errthrow() above as an + * error exception. If cstack is NULL, postpone the throw until do_cmdline() + * has returned (see do_one_cmd()). + */ + void +do_errthrow(cstack, cmdname) + struct condstack *cstack; + char_u *cmdname; +{ + /* + * Ensure that all commands in nested function calls and sourced files + * are aborted immediately. + */ + if (cause_abort) + { + cause_abort = FALSE; + force_abort = TRUE; + } + + /* If no exception is to be thrown or the conversion should be done after + * returning to a previous invocation of do_one_cmd(), do nothing. */ + if (*msg_list == NULL) + return; + + if (throw_exception(*msg_list, ET_ERROR, cmdname) == FAIL) + free_msglist(*msg_list); + else + { + if (cstack != NULL) + do_throw(cstack); + else + need_rethrow = TRUE; + } + *msg_list = NULL; +} + +/* + * do_intthrow(): Replace the current exception by an interrupt or interrupt + * exception if appropriate. Return TRUE if the current exception is discarded, + * FALSE otherwise. + */ + int +do_intthrow(cstack) + struct condstack *cstack; +{ + /* + * If no interrupt occurred or no try conditional is active and no exception + * is being thrown, do nothing (for compatibility of non-EH scripts). + */ + if (!got_int || (trylevel == 0 && !did_throw)) + return FALSE; + +#ifdef THROW_TEST /* avoid warning for condition always true */ + if (!THROW_ON_INTERRUPT) + { + /* + * The interrupt aborts everything except for executing finally clauses. + * Discard any user or error or interrupt exception currently being + * thrown. + */ + if (did_throw) + discard_current_exception(); + } + else +#endif + { + /* + * Throw an interrupt exception, so that everything will be aborted + * (except for executing finally clauses), until the interrupt exception + * is caught; if still uncaught at the top level, the script processing + * will be terminated then. - If an interrupt exception is already + * being thrown, do nothing. + * + */ + if (did_throw) + { + if (current_exception->type == ET_INTERRUPT) + return FALSE; + + /* An interrupt exception replaces any user or error exception. */ + discard_current_exception(); + } + if (throw_exception("Vim:Interrupt", ET_INTERRUPT, NULL) != FAIL) + do_throw(cstack); + } + + return TRUE; +} + + +/* + * Throw a new exception. Return FAIL when out of memory or it was tried to + * throw an illegal user exception. "value" is the exception string for a user + * or interrupt exception, or points to a message list in case of an error + * exception. + */ + static int +throw_exception(value, type, cmdname) + void *value; + int type; + char_u *cmdname; +{ + except_T *excp; + char_u *p, *mesg, *val; + int cmdlen; + + /* + * Disallow faking Interrupt or error exceptions as user exceptions. They + * would be treated differently from real interrupt or error exceptions when + * no active try block is found, see do_cmdline(). + */ + if (type == ET_USER) + { + if (STRNCMP((char_u *)value, "Vim", 3) == 0 && + (((char_u *)value)[3] == NUL || ((char_u *)value)[3] == ':' || + ((char_u *)value)[3] == '(')) + { + EMSG(_("E608: Cannot :throw exceptions with 'Vim' prefix")); + goto fail; + } + } + + excp = (except_T *)alloc((unsigned)sizeof(except_T)); + if (excp == NULL) + goto nomem; + + if (type == ET_ERROR) + { + /* Store the original message and prefix the exception value with + * "Vim:" or, if a command name is given, "Vim(cmdname):". */ + excp->messages = (struct msglist *)value; + mesg = excp->messages->throw_msg; + if (cmdname != NULL && *cmdname != NUL) + { + cmdlen = STRLEN(cmdname); + excp->value = vim_strnsave((char_u *)"Vim(", + 4 + cmdlen + 2 + (int)STRLEN(mesg)); + if (excp->value == NULL) + goto nomem; + STRCPY(&excp->value[4], cmdname); + STRCPY(&excp->value[4 + cmdlen], "):"); + val = excp->value + 4 + cmdlen + 2; + } + else + { + excp->value = vim_strnsave((char_u *)"Vim:", 4 + (int)STRLEN(mesg)); + if (excp->value == NULL) + goto nomem; + val = excp->value + 4; + } + + /* msg_add_fname may have been used to prefix the message with a file + * name in quotes. In the exception value, put the file name in + * parentheses and move it to the end. */ + for (p = mesg; ; p++) + { + if (*p == NUL + || (*p == 'E' + && VIM_ISDIGIT(p[1]) + && (p[2] == ':' + || (VIM_ISDIGIT(p[2]) + && (p[3] == ':' + || (VIM_ISDIGIT(p[3]) + && p[4] == ':')))))) + { + if (*p == NUL || p == mesg) /* 'E123' missing or at beginning */ + STRCAT(val, mesg); + else + { + /* '"filename" E123: message text' */ + if (mesg[0] != '"' || p-2 < &mesg[1] || + p[-2] != '"' || p[-1] != ' ') + /* "E123:" is part of the file name. */ + continue; + + STRCAT(val, p); + p[-2] = NUL; + sprintf((char *)(val + STRLEN(p)), " (%s)", &mesg[1]); + p[-2] = '"'; + } + break; + } + } + } + else + excp->value = value; + + excp->type = type; + excp->throw_name = vim_strsave(sourcing_name == NULL + ? (char_u *)"" : sourcing_name); + if (excp->throw_name == NULL) + { + if (type == ET_ERROR) + vim_free(excp->value); + goto nomem; + } + excp->throw_lnum = sourcing_lnum; + + if (p_verbose >= 13 || debug_break_level > 0) + { + int save_msg_silent = msg_silent; + + if (debug_break_level > 0) + msg_silent = FALSE; /* display messages */ + ++no_wait_return; + msg_scroll = TRUE; /* always scroll up, don't overwrite */ + msg_str((char_u *)_("Exception thrown: %s"), excp->value); + msg_puts((char_u *)"\n"); /* don't overwrite this either */ + cmdline_row = msg_row; + --no_wait_return; + if (debug_break_level > 0) + msg_silent = save_msg_silent; + } + + current_exception = excp; + return OK; + +nomem: + vim_free(excp); + suppress_errthrow = TRUE; + EMSG(_(e_outofmem)); +fail: + current_exception = NULL; + return FAIL; +} + +/* + * Discard an exception. "was_finished" is set when the exception has been + * caught and the catch clause has been ended normally. + */ + static void +discard_exception(excp, was_finished) + except_T *excp; + int was_finished; +{ + char_u *saved_IObuff; + + if (excp == NULL) + { + EMSG(_(e_internal)); + return; + } + + if (p_verbose >= 13 || debug_break_level > 0) + { + int save_msg_silent = msg_silent; + + saved_IObuff = vim_strsave(IObuff); + if (debug_break_level > 0) + msg_silent = FALSE; /* display messages */ + ++no_wait_return; + msg_scroll = TRUE; /* always scroll up, don't overwrite */ + msg_str(was_finished + ? (char_u *)_("Exception finished: %s") + : (char_u *)_("Exception discarded: %s"), + excp->value); + msg_puts((char_u *)"\n"); /* don't overwrite this either */ + cmdline_row = msg_row; + --no_wait_return; + if (debug_break_level > 0) + msg_silent = save_msg_silent; + STRCPY(IObuff, saved_IObuff); + vim_free(saved_IObuff); + } + if (excp->type != ET_INTERRUPT) + vim_free(excp->value); + if (excp->type == ET_ERROR) + free_msglist(excp->messages); + vim_free(excp->throw_name); + vim_free(excp); +} + +/* + * Discard the exception currently being thrown. + */ + void +discard_current_exception() +{ + discard_exception(current_exception, FALSE); + current_exception = NULL; + did_throw = FALSE; + need_rethrow = FALSE; +} + +/* + * Put an exception on the caught stack. + */ + static void +catch_exception(excp) + except_T *excp; +{ + excp->caught = caught_stack; + caught_stack = excp; + set_vim_var_string(VV_EXCEPTION, excp->value, -1); + if (*excp->throw_name != NUL) + { + if (excp->throw_lnum != 0) + sprintf((char *)IObuff, _("%s, line %ld"), excp->throw_name, + (long)excp->throw_lnum); + else + STRCPY(IObuff, excp->throw_name); + set_vim_var_string(VV_THROWPOINT, IObuff, -1); + } + else + /* throw_name not set on an exception from a command that was typed. */ + set_vim_var_string(VV_THROWPOINT, NULL, -1); + + if (p_verbose >= 13 || debug_break_level > 0) + { + int save_msg_silent = msg_silent; + + if (debug_break_level > 0) + msg_silent = FALSE; /* display messages */ + ++no_wait_return; + msg_scroll = TRUE; /* always scroll up, don't overwrite */ + msg_str((char_u *)_("Exception caught: %s"), excp->value); + msg_puts((char_u *)"\n"); /* don't overwrite this either */ + cmdline_row = msg_row; + --no_wait_return; + if (debug_break_level > 0) + msg_silent = save_msg_silent; + } +} + +/* + * Remove an exception from the caught stack. + */ + static void +finish_exception(excp) + except_T *excp; +{ + if (excp != caught_stack) + EMSG(_(e_internal)); + caught_stack = caught_stack->caught; + if (caught_stack != NULL) + { + set_vim_var_string(VV_EXCEPTION, caught_stack->value, -1); + if (*caught_stack->throw_name != NUL) + { + if (caught_stack->throw_lnum != 0) + sprintf((char *)IObuff, + _("%s, line %ld"), caught_stack->throw_name, + (long)caught_stack->throw_lnum); + else + STRCPY(IObuff, caught_stack->throw_name); + set_vim_var_string(VV_THROWPOINT, IObuff, -1); + } + else + /* throw_name not set on an exception from a command that was + * typed. */ + set_vim_var_string(VV_THROWPOINT, NULL, -1); + } + else + { + set_vim_var_string(VV_EXCEPTION, NULL, -1); + set_vim_var_string(VV_THROWPOINT, NULL, -1); + } + + /* Discard the exception, but use the finish message for 'verbose'. */ + discard_exception(excp, TRUE); +} + +/* + * Flags specifying the message displayed by report_pending. + */ +#define RP_MAKE 0 +#define RP_RESUME 1 +#define RP_DISCARD 2 + +/* + * Report information about something pending in a finally clause if required by + * the 'verbose' option or when debugging. "action" tells whether something is + * made pending or something pending is resumed or discarded. "pending" tells + * what is pending. "value" specifies the return value for a pending ":return" + * or the exception value for a pending exception. + */ + static void +report_pending(action, pending, value) + int action; + int pending; + void *value; +{ + char_u *mesg; + char *s; + int save_msg_silent; + + + switch (action) + { + case RP_MAKE: + mesg = (char_u *)_("%s made pending"); + break; + case RP_RESUME: + mesg = (char_u *)_("%s resumed"); + break; + /* case RP_DISCARD: */ + default: + mesg = (char_u *)_("%s discarded"); + break; + } + + switch (pending) + { + case CSTP_NONE: + return; + + case CSTP_CONTINUE: + s = ":continue"; + break; + case CSTP_BREAK: + s = ":break"; + break; + case CSTP_FINISH: + s = ":finish"; + break; + case CSTP_RETURN: + /* ":return" command producing value, allocated */ + s = (char *)get_return_cmd(value); + break; + + default: + if (pending & CSTP_THROW) + { + sprintf((char *)IObuff, (char *)mesg, _("Exception")); + mesg = vim_strnsave(IObuff, (int)STRLEN(IObuff) + 4); + STRCAT(mesg, ": %s"); + s = (char *)((except_T *)value)->value; + } + else if ((pending & CSTP_ERROR) && (pending & CSTP_INTERRUPT)) + s = _("Error and interrupt"); + else if (pending & CSTP_ERROR) + s = _("Error"); + else /* if (pending & CSTP_INTERRUPT) */ + s = _("Interrupt"); + } + + save_msg_silent = msg_silent; + if (debug_break_level > 0) + msg_silent = FALSE; /* display messages */ + ++no_wait_return; + msg_scroll = TRUE; /* always scroll up, don't overwrite */ + msg_str(mesg, (char_u *)s); + msg_puts((char_u *)"\n"); /* don't overwrite this either */ + cmdline_row = msg_row; + --no_wait_return; + if (debug_break_level > 0) + msg_silent = save_msg_silent; + + if (pending == CSTP_RETURN) + vim_free(s); + else if (pending & CSTP_THROW) + vim_free(mesg); +} + +/* + * If something is made pending in a finally clause, report it if required by + * the 'verbose' option or when debugging. + */ + void +report_make_pending(pending, value) + int pending; + void *value; +{ + if (p_verbose >= 14 || debug_break_level > 0) + report_pending(RP_MAKE, pending, value); +} + +/* + * If something pending in a finally clause is resumed at the ":endtry", report + * it if required by the 'verbose' option or when debugging. + */ + void +report_resume_pending(pending, value) + int pending; + void *value; +{ + if (p_verbose >= 14 || debug_break_level > 0) + report_pending(RP_RESUME, pending, value); +} + +/* + * If something pending in a finally clause is discarded, report it if required + * by the 'verbose' option or when debugging. + */ + void +report_discard_pending(pending, value) + int pending; + void *value; +{ + if (p_verbose >= 14 || debug_break_level > 0) + report_pending(RP_DISCARD, pending, value); +} + + +/* + * ":if". + */ + void +ex_if(eap) + exarg_T *eap; +{ + int error; + int skip; + int result; + struct condstack *cstack = eap->cstack; + + if (cstack->cs_idx == CSTACK_LEN - 1) + eap->errmsg = (char_u *)N_("E579: :if nesting too deep"); + else + { + ++cstack->cs_idx; + cstack->cs_flags[cstack->cs_idx] = 0; + + /* + * Don't do something after an error, interrupt, or throw, or when there + * is a surrounding conditional and it was not active. + */ + skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0 + && !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE)); + + result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip); + + if (!skip && !error) + { + if (result) + cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE | CSF_TRUE; + } + else + /* set TRUE, so this conditional will never get active */ + cstack->cs_flags[cstack->cs_idx] = CSF_TRUE; + } +} + +/* + * ":endif". + */ + void +ex_endif(eap) + exarg_T *eap; +{ + did_endif = TRUE; + if (eap->cstack->cs_idx < 0 + || (eap->cstack->cs_flags[eap->cstack->cs_idx] & + (CSF_WHILE | CSF_TRY))) + eap->errmsg = (char_u *)N_("E580: :endif without :if"); + else + { + /* + * When debugging or a breakpoint was encountered, display the debug + * prompt (if not already done). This shows the user that an ":endif" + * is executed when the ":if" or a previous ":elseif" was not TRUE. + * Handle a ">quit" debug command as if an interrupt had occurred before + * the ":endif". That is, throw an interrupt exception if appropriate. + * Doing this here prevents an exception for a parsing error being + * discarded by throwing the interrupt exception later on. + */ + if (!(eap->cstack->cs_flags[eap->cstack->cs_idx] & CSF_TRUE) && + dbg_check_skipped(eap)) + (void)do_intthrow(eap->cstack); + + --eap->cstack->cs_idx; + } +} + +/* + * ":else" and ":elseif". + */ + void +ex_else(eap) + exarg_T *eap; +{ + int error; + int skip; + int result; + struct condstack *cstack = eap->cstack; + + /* + * Don't do something after an error, interrupt, or throw, or when there is + * a surrounding conditional and it was not active. + */ + skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0 + && !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE)); + + if (cstack->cs_idx < 0 + || (cstack->cs_flags[cstack->cs_idx] & (CSF_WHILE | CSF_TRY))) + { + if (eap->cmdidx == CMD_else) + { + eap->errmsg = (char_u *)N_("E581: :else without :if"); + return; + } + eap->errmsg = (char_u *)N_("E582: :elseif without :if"); + skip = TRUE; + } + else if (cstack->cs_flags[cstack->cs_idx] & CSF_ELSE) + { + if (eap->cmdidx == CMD_else) + { + eap->errmsg = (char_u *)N_("E583: multiple :else"); + return; + } + eap->errmsg = (char_u *)N_("E584: :elseif after :else"); + skip = TRUE; + } + + /* if skipping or the ":if" was TRUE, reset ACTIVE, otherwise set it */ + if (skip || cstack->cs_flags[cstack->cs_idx] & CSF_TRUE) + { + if (eap->errmsg == NULL) + cstack->cs_flags[cstack->cs_idx] = CSF_TRUE; + skip = TRUE; /* don't evaluate an ":elseif" */ + } + else + cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE; + + /* + * When debugging or a breakpoint was encountered, display the debug prompt + * (if not already done). This shows the user that an ":else" or ":elseif" + * is executed when the ":if" or previous ":elseif" was not TRUE. Handle + * a ">quit" debug command as if an interrupt had occurred before the + * ":else" or ":elseif". That is, set "skip" and throw an interrupt + * exception if appropriate. Doing this here prevents that an exception + * for a parsing errors is discarded when throwing the interrupt exception + * later on. + */ + if (!skip && dbg_check_skipped(eap) && got_int) + { + (void)do_intthrow(cstack); + skip = TRUE; + } + + if (eap->cmdidx == CMD_elseif) + { + result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip); + /* When throwing error exceptions, we want to throw always the first + * of several errors in a row. This is what actually happens when + * a conditional error was detected above and there is another failure + * when parsing the expression. Since the skip flag is set in this + * case, the parsing error will be ignored by emsg(). */ + + if (!skip && !error) + { + if (result) + cstack->cs_flags[cstack->cs_idx] = CSF_ACTIVE | CSF_TRUE; + else + cstack->cs_flags[cstack->cs_idx] = 0; + } + else if (eap->errmsg == NULL) + /* set TRUE, so this conditional will never get active */ + cstack->cs_flags[cstack->cs_idx] = CSF_TRUE; + } + else + cstack->cs_flags[cstack->cs_idx] |= CSF_ELSE; +} + +/* + * Handle ":while". + */ + void +ex_while(eap) + exarg_T *eap; +{ + int error; + int skip; + int result; + struct condstack *cstack = eap->cstack; + + if (cstack->cs_idx == CSTACK_LEN - 1) + eap->errmsg = (char_u *)N_("E585: :while nesting too deep"); + else + { + /* + * cs_had_while is set when we have jumped back from the matching + * ":endwhile". When not set, need to initialise this cstack entry. + */ + if (!cstack->cs_had_while) + { + ++cstack->cs_idx; + ++cstack->cs_whilelevel; + cstack->cs_line[cstack->cs_idx] = -1; + } + cstack->cs_flags[cstack->cs_idx] = CSF_WHILE; + + /* + * Don't do something after an error, interrupt, or throw, or when there + * is a surrounding conditional and it was not active. + */ + skip = did_emsg || got_int || did_throw || (cstack->cs_idx > 0 + && !(cstack->cs_flags[cstack->cs_idx - 1] & CSF_ACTIVE)); + result = eval_to_bool(eap->arg, &error, &eap->nextcmd, skip); + + /* + * If this cstack entry was just initialised and is active, set + * cs_had_while flag, so do_cmdline() will set the line number + * in cs_line[]. + */ + if (!skip && !error && result) + { + cstack->cs_flags[cstack->cs_idx] |= CSF_ACTIVE | CSF_TRUE; + cstack->cs_had_while = !cstack->cs_had_while; + } + else + { + cstack->cs_had_while = FALSE; + /* If the ":while" evaluates to FALSE, show the debug prompt at the + * ":endwhile" as if there was a ":break" in a ":while" evaluating + * to TRUE. */ + if (!skip && !error) + cstack->cs_flags[cstack->cs_idx] |= CSF_TRUE; + } + } +} + +/* + * ":continue" + */ + void +ex_continue(eap) + exarg_T *eap; +{ + int idx; + struct condstack *cstack = eap->cstack; + + if (cstack->cs_whilelevel <= 0 || cstack->cs_idx < 0) + eap->errmsg = (char_u *)N_("E586: :continue without :while"); + else + { + /* Try to find the matching ":while". This might stop at a try + * conditional not in its finally clause (which is then to be executed + * next). Therefor, inactivate all conditionals except the ":while" + * itself (if reached). */ + idx = cleanup_conditionals(cstack, CSF_WHILE, FALSE); + if ((cstack->cs_flags[idx] & CSF_WHILE)) + { + if (cstack->cs_idx > idx) + rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel); + + /* + * Set cs_had_continue, so do_cmdline() will jump back to the + * matching ":while". + */ + cstack->cs_had_continue = TRUE; /* let do_cmdline() handle it */ + } + else + { + /* If a try conditional not in its finally clause is reached first, + * make the ":continue" pending for execution at the ":endtry". */ + cstack->cs_pending[idx] = CSTP_CONTINUE; + report_make_pending(CSTP_CONTINUE, NULL); + } + } +} + +/* + * ":break" + */ + void +ex_break(eap) + exarg_T *eap; +{ + int idx; + struct condstack *cstack = eap->cstack; + + if (cstack->cs_whilelevel <= 0 || cstack->cs_idx < 0) + eap->errmsg = (char_u *)N_("E587: :break without :while"); + else + { + /* Inactivate conditionals until the matching ":while" or a try + * conditional not in its finally clause (which is then to be + * executed next) is found. In the latter case, make the ":break" + * pending for execution at the ":endtry". */ + idx = cleanup_conditionals(cstack, CSF_WHILE, TRUE); + if (!(cstack->cs_flags[idx] & CSF_WHILE)) + { + cstack->cs_pending[idx] = CSTP_BREAK; + report_make_pending(CSTP_BREAK, NULL); + } + } +} + +/* + * ":endwhile" + */ + void +ex_endwhile(eap) + exarg_T *eap; +{ + struct condstack *cstack = eap->cstack; + int idx; + + if (cstack->cs_whilelevel <= 0 || cstack->cs_idx < 0) + eap->errmsg = e_while; + else + { + if (!(cstack->cs_flags[cstack->cs_idx] & CSF_WHILE)) + { + /* Try to find the matching ":while" and report what's missing. */ + if (!(cstack->cs_flags[cstack->cs_idx] & CSF_TRY)) + eap->errmsg = e_endif; + else if (cstack->cs_flags[cstack->cs_idx] & CSF_FINALLY) + eap->errmsg = e_endtry; + for (idx = cstack->cs_idx; idx > 0; --idx) + { + if ((cstack->cs_flags[idx] & CSF_TRY) + && !(cstack->cs_flags[idx] & CSF_FINALLY)) + { + /* Give up at a try conditional not in its finally clause. + * Ignore the ":endwhile". */ + eap->errmsg = e_while; + return; + } + if (cstack->cs_flags[idx] & CSF_WHILE) + break; + } + /* Cleanup and rewind all contained (and unclosed) conditionals. */ + (void)cleanup_conditionals(cstack, CSF_WHILE, FALSE); + rewind_conditionals(cstack, idx, CSF_TRY, &cstack->cs_trylevel); + } + |