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Diffstat (limited to 'src')
| -rw-r--r-- | src/error.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/src/error.c b/src/error.c new file mode 100644 index 0000000..ee39ccf --- /dev/null +++ b/src/error.c @@ -0,0 +1,188 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * 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/>. + */ +#include <error.h> +#include <unistd.h> +#include <stdio.h> +#include <errno.h> + + + +/** + * Print an error message with a detailed description, and optionally exit. + * + * This is a GNU extension. + * + * @param status The process will exit, with the function returning, with this + * exit status, unless it is zero. If zero, the process shall not exit. + * @param errnum The value of `errno` when the error occurred, zero if the a textual + * description of the error, further than that of `format`, shall not + * be printed. + * @param format Formatting-string for a detailed description of what happend. + * @param args Formatting-arguments for `format`. + */ +void error(int status, int errnum, const char* format, ...) +{ + va_list args; + va_start(args, format); + verror_at_line(status, errnum, NULL, 0, format, args); + va_end(args); +} + + +/** + * Variant of `error` that uses `va_list` instead of variadic arguments. + * + * This is a slibc extension to the GNU extension `error`. + * + * @param status The process will exit, with the function returning, with this + * exit status, unless it is zero. If zero, the process shall not exit. + * @param errnum The value of `errno` when the error occurred, zero if the a textual + * description of the error, further than that of `format`, shall not + * be printed. + * @param format Formatting-string for a detailed description of what happend. + * @param args Formatting-arguments for `format`. + */ +void verror(int status, int errnum, const char* format, va_list args) +{ + verror_at_line(status, errnum, NULL, 0, format, args); +} + + +/** + * Variant of `error` that prints the filename and the line + * number whence the error occurred. + * + * This is a GNU extension. + * + * @param status The process will exit, with the function returning, with this + * exit status, unless it is zero. If zero, the process shall not exit. + * @param errnum The value of `errno` when the error occurred, zero if the a textual + * description of the error, further than that of `format`, shall not + * be printed. + * @param filename The filename of the source code file where the error occurred. + * @param linenum The line number of in the source code file where the error occurred. + * @param format Formatting-string for a detailed description of what happend. + * @param args Formatting-arguments for `format`. + */ +void error_at_line(int status, int errnum, const char* filename, + unsigned int linenum, const char* format, ...) +{ + va_list args; + va_start(args, format); + verror_at_line(status, errnu, filename, linenum, format, args); + va_end(args); +} + + +/** + * Variant of `verror` that prints the filename and the line + * number whence the error occurred. + * + * This is a slibc extension to the GNU extension `error_at_line`. + * + * @param status The process will exit, with the function returning, with this + * exit status, unless it is zero. If zero, the process shall not exit. + * @param errnum The value of `errno` when the error occurred, zero if the a textual + * description of the error, further than that of `format`, shall not + * be printed. + * @param filename The filename of the source code file where the error occurred. + * @param linenum The line number of in the source code file where the error occurred. + * @param format Formatting-string for a detailed description of what happend. + * @param args Formatting-arguments for `format`. + */ +void verror_at_line(int status, int errnum, const char* filename, + unsigned int linenum, const char* format, va_list args) +{ + int tty = isatty(STDERR_FILENO); + void (*pname)(void) = error_print_progname; + + static const char* last_filename = NULL; + static unsigned int last_linenum = 0; + static int last_errnum = 0; + + if (error_one_per_line) + if ((last_filename == filename) && (last_linenum == linenum) && (last_errnum == errnum)) + goto skip_print; + + if (pname != NULL) + pname(); + else + { + fflush(stdout); + fprintf(stderr, "%(\033[0;1;31m)%s%(\033[0m)", + tty, program_invocation_name, tty); + } + + fprintf(stderr, "%(: %(\033[35m%)%s%(\033[0m%): %(\033[32m%)%u%(\033[0m%)%)%(: %s%)%(: %)", + filename != NULL, tty, filename, tty, tty, filenum, tty, + errnum != 0, strerror(errnum) /* TODO strerror is not MT-Safe */, format != NULL); + + if (filename != NULL) + last_filename = filename, last_linenum = linenum, last_errnum = errnum; + + vfprintf(stderr, format, args); + fprintf(stderr, "\n", program_invocation_name); + fflush(stderr); + + skip_print: + error_message_count++; /* TODO lock around this */ + if (status) + exit(status); +} + + +/** + * Counts the number of times `error` ( verror`) and + * `error_at_line` (`verror_at_line`) has returned. + * This variable is global and shared by all threads. + * + * This is a GNU extension. + */ +volatile unsigned int error_message_count = 0; + + +/** + * If set to non-zero (the default), `error_at_line` + * and `verror_at_line` restrict themself to only + * print an error the first time it appears. This + * is determined by the uniqueness of the combination + * of the values on `filename` and `linenum`. However + * it will forget the line the next time the function + * is called from a different line. This variable is + * global and shared by all threads. Has a slibc + * modification, `errnum` is also remembered, meaning + * if the error code is different (zero is considered + * an error code), the error is printed even if it + * occurred on the same line as the last time. + * + * This is a GNU extension. + */ +volatile int error_one_per_line = 1; + + +/** + * If not `NULL`, this function is used instead of + * flushing stdout and printing the process name to + * stderr, by `error` (`verror`) and `verror_at_line` + * (`verror_at_line`). This variable is global and + * shared by all threads. + * + * This is a GNU extension. + */ +volatile void (*error_print_progname)(void) = NULL; + |