diff options
Diffstat (limited to 'src/util.c')
| -rw-r--r-- | src/util.c | 1577 |
1 files changed, 1577 insertions, 0 deletions
diff --git a/src/util.c b/src/util.c new file mode 100644 index 0000000..76872cb --- /dev/null +++ b/src/util.c @@ -0,0 +1,1577 @@ +/* Support routines for GNU DIFF. + + Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006, 2009-2013, + 2015-2016 Free Software Foundation, Inc. + + This file is part of GNU DIFF. + + 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 "diff.h" +#include "argmatch.h" +#include <dirname.h> +#include <error.h> +#include <system-quote.h> +#include <xalloc.h> +#include "xvasprintf.h" +#include <signal.h> + +/* Use SA_NOCLDSTOP as a proxy for whether the sigaction machinery is + present. */ +#ifndef SA_NOCLDSTOP +# define SA_NOCLDSTOP 0 +# define sigprocmask(How, Set, Oset) /* empty */ +# define sigset_t int +# if ! HAVE_SIGINTERRUPT +# define siginterrupt(sig, flag) /* empty */ +# endif +#endif + +#ifndef SA_RESTART +# define SA_RESTART 0 +#endif + +char const pr_program[] = PR_PROGRAM; + +/* Queue up one-line messages to be printed at the end, + when -l is specified. Each message is recorded with a 'struct msg'. */ + +struct msg +{ + struct msg *next; + char args[1]; /* Format + 4 args, each '\0' terminated, concatenated. */ +}; + +/* Head of the chain of queues messages. */ + +static struct msg *msg_chain; + +/* Tail of the chain of queues messages. */ + +static struct msg **msg_chain_end = &msg_chain; + +/* Use when a system call returns non-zero status. + NAME should normally be the file name. */ + +void +perror_with_name (char const *name) +{ + error (0, errno, "%s", name); +} + +/* Use when a system call returns non-zero status and that is fatal. */ + +void +pfatal_with_name (char const *name) +{ + int e = errno; + print_message_queue (); + error (EXIT_TROUBLE, e, "%s", name); + abort (); +} + +/* Print an error message containing MSGID, then exit. */ + +void +fatal (char const *msgid) +{ + print_message_queue (); + error (EXIT_TROUBLE, 0, "%s", _(msgid)); + abort (); +} + +/* Like printf, except if -l in effect then save the message and print later. + This is used for things like "Only in ...". */ + +void +message (char const *format_msgid, char const *arg1, char const *arg2) +{ + message5 (format_msgid, arg1, arg2, 0, 0); +} + +void +message5 (char const *format_msgid, char const *arg1, char const *arg2, + char const *arg3, char const *arg4) +{ + if (paginate) + { + char *p; + char const *arg[5]; + int i; + size_t size[5]; + size_t total_size = offsetof (struct msg, args); + struct msg *new; + + arg[0] = format_msgid; + arg[1] = arg1; + arg[2] = arg2; + arg[3] = arg3 ? arg3 : ""; + arg[4] = arg4 ? arg4 : ""; + + for (i = 0; i < 5; i++) + total_size += size[i] = strlen (arg[i]) + 1; + + new = xmalloc (total_size); + + for (i = 0, p = new->args; i < 5; p += size[i++]) + memcpy (p, arg[i], size[i]); + + *msg_chain_end = new; + new->next = 0; + msg_chain_end = &new->next; + } + else + { + if (sdiff_merge_assist) + putchar (' '); + printf (_(format_msgid), arg1, arg2, arg3, arg4); + } +} + +/* Output all the messages that were saved up by calls to 'message'. */ + +void +print_message_queue (void) +{ + char const *arg[5]; + int i; + struct msg *m = msg_chain; + + while (m) + { + struct msg *next = m->next; + arg[0] = m->args; + for (i = 0; i < 4; i++) + arg[i + 1] = arg[i] + strlen (arg[i]) + 1; + printf (_(arg[0]), arg[1], arg[2], arg[3], arg[4]); + free (m); + m = next; + } +} + +/* The set of signals that are caught. */ + +static sigset_t caught_signals; + +/* If nonzero, the value of the pending fatal signal. */ + +static sig_atomic_t volatile interrupt_signal; + +/* A count of the number of pending stop signals that have been received. */ + +static sig_atomic_t volatile stop_signal_count; + +/* An ordinary signal was received; arrange for the program to exit. */ + +static void +sighandler (int sig) +{ + if (! SA_NOCLDSTOP) + signal (sig, SIG_IGN); + if (! interrupt_signal) + interrupt_signal = sig; +} + +/* A SIGTSTP was received; arrange for the program to suspend itself. */ + +static void +stophandler (int sig) +{ + if (! SA_NOCLDSTOP) + signal (sig, stophandler); + if (! interrupt_signal) + stop_signal_count++; +} +/* Process any pending signals. If signals are caught, this function + should be called periodically. Ideally there should never be an + unbounded amount of time when signals are not being processed. + Signal handling can restore the default colors, so callers must + immediately change colors after invoking this function. */ + +static void +process_signals (void) +{ + while (interrupt_signal || stop_signal_count) + { + int sig; + int stops; + sigset_t oldset; + + set_color_context (RESET_CONTEXT); + fflush (stdout); + + sigprocmask (SIG_BLOCK, &caught_signals, &oldset); + + /* Reload interrupt_signal and stop_signal_count, in case a new + signal was handled before sigprocmask took effect. */ + sig = interrupt_signal; + stops = stop_signal_count; + + /* SIGTSTP is special, since the application can receive that signal + more than once. In this case, don't set the signal handler to the + default. Instead, just raise the uncatchable SIGSTOP. */ + if (stops) + { + stop_signal_count = stops - 1; + sig = SIGSTOP; + } + else + signal (sig, SIG_DFL); + + /* Exit or suspend the program. */ + raise (sig); + sigprocmask (SIG_SETMASK, &oldset, NULL); + + /* If execution reaches here, then the program has been + continued (after being suspended). */ + } +} + +static void +install_signal_handlers (void) +{ + /* The signals that are trapped, and the number of such signals. */ + static int const sig[] = + { + /* This one is handled specially. */ + SIGTSTP, + + /* The usual suspects. */ + SIGALRM, SIGHUP, SIGINT, SIGPIPE, SIGQUIT, SIGTERM, +#ifdef SIGPOLL + SIGPOLL, +#endif +#ifdef SIGPROF + SIGPROF, +#endif +#ifdef SIGVTALRM + SIGVTALRM, +#endif +#ifdef SIGXCPU + SIGXCPU, +#endif +#ifdef SIGXFSZ + SIGXFSZ, +#endif + }; + enum { nsigs = sizeof (sig) / sizeof *(sig) }; + +#if ! SA_NOCLDSTOP + bool caught_sig[nsigs]; +#endif + { + int j; +#if SA_NOCLDSTOP + struct sigaction act; + + sigemptyset (&caught_signals); + for (j = 0; j < nsigs; j++) + { + sigaction (sig[j], NULL, &act); + if (act.sa_handler != SIG_IGN) + sigaddset (&caught_signals, sig[j]); + } + + act.sa_mask = caught_signals; + act.sa_flags = SA_RESTART; + + for (j = 0; j < nsigs; j++) + if (sigismember (&caught_signals, sig[j])) + { + act.sa_handler = sig[j] == SIGTSTP ? stophandler : sighandler; + sigaction (sig[j], &act, NULL); + } +#else + for (j = 0; j < nsigs; j++) + { + caught_sig[j] = (signal (sig[j], SIG_IGN) != SIG_IGN); + if (caught_sig[j]) + { + signal (sig[j], sig[j] == SIGTSTP ? stophandler : sighandler); + siginterrupt (sig[j], 0); + } + } +#endif + } +} + +static char const *current_name0; +static char const *current_name1; +static bool currently_recursive; +static bool colors_enabled; + +static struct color_ext_type *color_ext_list = NULL; + +struct bin_str + { + size_t len; /* Number of bytes */ + const char *string; /* Pointer to the same */ + }; + +struct color_ext_type + { + struct bin_str ext; /* The extension we're looking for */ + struct bin_str seq; /* The sequence to output when we do */ + struct color_ext_type *next; /* Next in list */ + }; + +/* Parse a string as part of the --palette argument; this may involve + decoding all kinds of escape characters. If equals_end is set an + unescaped equal sign ends the string, otherwise only a : or \0 + does. Set *OUTPUT_COUNT to the number of bytes output. Return + true if successful. + + The resulting string is *not* null-terminated, but may contain + embedded nulls. + + Note that both dest and src are char **; on return they point to + the first free byte after the array and the character that ended + the input string, respectively. */ + +static bool +get_funky_string (char **dest, const char **src, bool equals_end, + size_t *output_count) +{ + char num; /* For numerical codes */ + size_t count; /* Something to count with */ + enum { + ST_GND, ST_BACKSLASH, ST_OCTAL, ST_HEX, ST_CARET, ST_END, ST_ERROR + } state; + const char *p; + char *q; + + p = *src; /* We don't want to double-indirect */ + q = *dest; /* the whole darn time. */ + + count = 0; /* No characters counted in yet. */ + num = 0; + + state = ST_GND; /* Start in ground state. */ + while (state < ST_END) + { + switch (state) + { + case ST_GND: /* Ground state (no escapes) */ + switch (*p) + { + case ':': + case '\0': + state = ST_END; /* End of string */ + break; + case '\\': + state = ST_BACKSLASH; /* Backslash scape sequence */ + ++p; + break; + case '^': + state = ST_CARET; /* Caret escape */ + ++p; + break; + case '=': + if (equals_end) + { + state = ST_END; /* End */ + break; + } + /* else fall through */ + default: + *(q++) = *(p++); + ++count; + break; + } + break; + + case ST_BACKSLASH: /* Backslash escaped character */ + switch (*p) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + state = ST_OCTAL; /* Octal sequence */ + num = *p - '0'; + break; + case 'x': + case 'X': + state = ST_HEX; /* Hex sequence */ + num = 0; + break; + case 'a': /* Bell */ + num = '\a'; + break; + case 'b': /* Backspace */ + num = '\b'; + break; + case 'e': /* Escape */ + num = 27; + break; + case 'f': /* Form feed */ + num = '\f'; + break; + case 'n': /* Newline */ + num = '\n'; + break; + case 'r': /* Carriage return */ + num = '\r'; + break; + case 't': /* Tab */ + num = '\t'; + break; + case 'v': /* Vtab */ + num = '\v'; + break; + case '?': /* Delete */ + num = 127; + break; + case '_': /* Space */ + num = ' '; + break; + case '\0': /* End of string */ + state = ST_ERROR; /* Error! */ + break; + default: /* Escaped character like \ ^ : = */ + num = *p; + break; + } + if (state == ST_BACKSLASH) + { + *(q++) = num; + ++count; + state = ST_GND; + } + ++p; + break; + + case ST_OCTAL: /* Octal sequence */ + if (*p < '0' || *p > '7') + { + *(q++) = num; + ++count; + state = ST_GND; + } + else + num = (num << 3) + (*(p++) - '0'); + break; + + case ST_HEX: /* Hex sequence */ + switch (*p) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + num = (num << 4) + (*(p++) - '0'); + break; + case 'a': + case 'b': + case 'c': + case 'd': + case 'e': + case 'f': + num = (num << 4) + (*(p++) - 'a') + 10; + break; + case 'A': + case 'B': + case 'C': + case 'D': + case 'E': + case 'F': + num = (num << 4) + (*(p++) - 'A') + 10; + break; + default: + *(q++) = num; + ++count; + state = ST_GND; + break; + } + break; + + case ST_CARET: /* Caret escape */ + state = ST_GND; /* Should be the next state... */ + if (*p >= '@' && *p <= '~') + { + *(q++) = *(p++) & 037; + ++count; + } + else if (*p == '?') + { + *(q++) = 127; + ++count; + } + else + state = ST_ERROR; + break; + + default: + abort (); + } + } + + *dest = q; + *src = p; + *output_count = count; + + return state != ST_ERROR; +} + +enum parse_state + { + PS_START = 1, + PS_2, + PS_3, + PS_4, + PS_DONE, + PS_FAIL + }; + +#define LEN_STR_PAIR(s) sizeof (s) - 1, s + +static struct bin_str color_indicator[] = + { + { LEN_STR_PAIR ("\033[") }, /* lc: Left of color sequence */ + { LEN_STR_PAIR ("m") }, /* rc: Right of color sequence */ + { 0, NULL }, /* ec: End color (replaces lc+rs+rc) */ + { LEN_STR_PAIR ("0") }, /* rs: Reset to ordinary colors */ + { LEN_STR_PAIR ("1") }, /* hd: Header */ + { LEN_STR_PAIR ("32") }, /* ad: Add line */ + { LEN_STR_PAIR ("31") }, /* de: Delete line */ + { LEN_STR_PAIR ("36") }, /* ln: Line number */ + }; + +static const char *const indicator_name[] = + { + "lc", "rc", "ec", "rs", "hd", "ad", "de", "ln", NULL + }; +ARGMATCH_VERIFY (indicator_name, color_indicator); + +static char const *color_palette; + +void +set_color_palette (char const *palette) +{ + color_palette = palette; +} + +static void +parse_diff_color (void) +{ + char *color_buf; + const char *p; /* Pointer to character being parsed */ + char *buf; /* color_buf buffer pointer */ + int ind_no; /* Indicator number */ + char label[3]; /* Indicator label */ + struct color_ext_type *ext; /* Extension we are working on */ + + if ((p = color_palette) == NULL || *p == '\0') + return; + + ext = NULL; + strcpy (label, "??"); + + /* This is an overly conservative estimate, but any possible + --palette string will *not* generate a color_buf longer than + itself, so it is a safe way of allocating a buffer in + advance. */ + buf = color_buf = xstrdup (p); + + enum parse_state state = PS_START; + while (true) + { + switch (state) + { + case PS_START: /* First label character */ + switch (*p) + { + case ':': + ++p; + break; + + case '*': + /* Allocate new extension block and add to head of + linked list (this way a later definition will + override an earlier one, which can be useful for + having terminal-specific defs override global). */ + + ext = xmalloc (sizeof *ext); + ext->next = color_ext_list; + color_ext_list = ext; + + ++p; + ext->ext.string = buf; + + state = (get_funky_string (&buf, &p, true, &ext->ext.len) + ? PS_4 : PS_FAIL); + break; + + case '\0': + state = PS_DONE; /* Done! */ + goto done; + + default: /* Assume it is file type label */ + label[0] = *(p++); + state = PS_2; + break; + } + break; + + case PS_2: /* Second label character */ + if (*p) + { + label[1] = *(p++); + state = PS_3; + } + else + state = PS_FAIL; /* Error */ + break; + + case PS_3: /* Equal sign after indicator label */ + state = PS_FAIL; /* Assume failure... */ + if (*(p++) == '=')/* It *should* be... */ + { + for (ind_no = 0; indicator_name[ind_no] != NULL; ++ind_no) + { + if (STREQ (label, indicator_name[ind_no])) + { + color_indicator[ind_no].string = buf; + state = (get_funky_string (&buf, &p, false, + &color_indicator[ind_no].len) + ? PS_START : PS_FAIL); + break; + } + } + if (state == PS_FAIL) + error (0, 0, _("unrecognized prefix: %s"), label); + } + break; + + case PS_4: /* Equal sign after *.ext */ + if (*(p++) == '=') + { + ext->seq.string = buf; + state = (get_funky_string (&buf, &p, false, &ext->seq.len) + ? PS_START : PS_FAIL); + } + else + state = PS_FAIL; + break; + + case PS_FAIL: + goto done; + + default: + abort (); + } + } + done: + + if (state == PS_FAIL) + { + struct color_ext_type *e; + struct color_ext_type *e2; + + error (0, 0, + _("unparsable value for --palette")); + free (color_buf); + for (e = color_ext_list; e != NULL; /* empty */) + { + e2 = e; + e = e->next; + free (e2); + } + colors_enabled = false; + } +} + +static void +check_color_output (bool is_pipe) +{ + bool output_is_tty; + + if (! outfile || colors_style == NEVER) + return; + + output_is_tty = presume_output_tty || (!is_pipe && isatty (fileno (outfile))); + + colors_enabled = (colors_style == ALWAYS + || (colors_style == AUTO && output_is_tty)); + + if (colors_enabled) + parse_diff_color (); + + if (output_is_tty) + install_signal_handlers (); +} + +/* Call before outputting the results of comparing files NAME0 and NAME1 + to set up OUTFILE, the stdio stream for the output to go to. + + Usually, OUTFILE is just stdout. But when -l was specified + we fork off a 'pr' and make OUTFILE a pipe to it. + 'pr' then outputs to our stdout. */ + +void +setup_output (char const *name0, char const *name1, bool recursive) +{ + current_name0 = name0; + current_name1 = name1; + currently_recursive = recursive; + outfile = 0; +} + +#if HAVE_WORKING_FORK +static pid_t pr_pid; +#endif + +static char c_escape_char (char c) +{ + switch (c) { + case '\a': return 'a'; + case '\b': return 'b'; + case '\t': return 't'; + case '\n': return 'n'; + case '\v': return 'v'; + case '\f': return 'f'; + case '\r': return 'r'; + case '"': return '"'; + case '\\': return '\\'; + default: + return c < 32; + } +} + +static char * +c_escape (char const *str) +{ + char const *s; + size_t plus = 0; + bool must_quote = false; + + for (s = str; *s; s++) + { + char c = *s; + + if (c == ' ') + { + must_quote = true; + continue; + } + switch (c_escape_char (*s)) + { + case 1: + plus += 3; + /* fall through */ + case 0: + break; + default: + plus++; + break; + } + } + + if (must_quote || plus) + { + size_t s_len = s - str; + char *buffer = xmalloc (s_len + plus + 3); + char *b = buffer; + + *b++ = '"'; + for (s = str; *s; s++) + { + char c = *s; + char escape = c_escape_char (c); + + switch (escape) + { + case 0: + *b++ = c; + break; + case 1: + *b++ = '\\'; + *b++ = ((c >> 6) & 03) + '0'; + *b++ = ((c >> 3) & 07) + '0'; + *b++ = ((c >> 0) & 07) + '0'; + break; + default: + *b++ = '\\'; + *b++ = escape; + break; + } + } + *b++ = '"'; + *b = 0; + return buffer; + } + + return (char *) str; +} + +void +begin_output (void) +{ + char *names[2]; + char *name; + + if (outfile != 0) + return; + + names[0] = c_escape (current_name0); + names[1] = c_escape (current_name1); + + /* Construct the header of this piece of diff. */ + /* POSIX 1003.1-2001 specifies this format. But there are some bugs in + the standard: it says that we must print only the last component + of the pathnames, and it requires two spaces after "diff" if + there are no options. These requirements are silly and do not + match historical practice. */ + name = xasprintf ("diff%s %s %s", switch_string, names[0], names[1]); + + if (paginate) + { + char const *argv[4]; + + if (fflush (stdout) != 0) + pfatal_with_name (_("write failed")); + + argv[0] = pr_program; + argv[1] = "-h"; + argv[2] = name; + argv[3] = 0; + + /* Make OUTFILE a pipe to a subsidiary 'pr'. */ + { +#if HAVE_WORKING_FORK + int pipes[2]; + + if (pipe (pipes) != 0) + pfatal_with_name ("pipe"); + + pr_pid = fork (); + if (pr_pid < 0) + pfatal_with_name ("fork"); + + if (pr_pid == 0) + { + close (pipes[1]); + if (pipes[0] != STDIN_FILENO) + { + if (dup2 (pipes[0], STDIN_FILENO) < 0) + pfatal_with_name ("dup2"); + close (pipes[0]); + } + + execv (pr_program, (char **) argv); + _exit (errno == ENOENT ? 127 : 126); + } + else + { + close (pipes[0]); + outfile = fdopen (pipes[1], "w"); + if (!outfile) + pfatal_with_name ("fdopen"); + check_color_output (true); + } +#else + char *command = system_quote_argv (SCI_SYSTEM, (char **) argv); + errno = 0; + outfile = popen (command, "w"); + if (!outfile) + pfatal_with_name (command); + check_color_output (true); + free (command); +#endif + } + } + else + { + + /* If -l was not specified, output the diff straight to 'stdout'. */ + + outfile = stdout; + check_color_output (false); + + /* If handling multiple files (because scanning a directory), + print which files the following output is about. */ + if (currently_recursive) + printf ("%s\n", name); + } + + free (name); + + /* A special header is needed at the beginning of context output. */ + switch (output_style) + { + case OUTPUT_CONTEXT: + print_context_header (files, (char const *const *)names, false); + break; + + case OUTPUT_UNIFIED: + print_context_header (files, (char const *const *)names, true); + break; + + default: + break; + } + + if (names[0] != current_name0) + free (names[0]); + if (names[1] != current_name1) + free (names[1]); +} + +/* Call after the end of output of diffs for one file. + Close OUTFILE and get rid of the 'pr' subfork. */ + +void +finish_output (void) +{ + if (outfile != 0 && outfile != stdout) + { + int status; + int wstatus; + int werrno = 0; + if (ferror (outfile)) + fatal ("write failed"); +#if ! HAVE_WORKING_FORK + wstatus = pclose (outfile); + if (wstatus == -1) + werrno = errno; +#else + if (fclose (outfile) != 0) + pfatal_with_name (_("write failed")); + if (waitpid (pr_pid, &wstatus, 0) < 0) + pfatal_with_name ("waitpid"); +#endif + status = (! werrno && WIFEXITED (wstatus) + ? WEXITSTATUS (wstatus) + : INT_MAX); + if (status) + error (EXIT_TROUBLE, werrno, + _(status == 126 + ? "subsidiary program '%s' could not be invoked" + : status == 127 + ? "subsidiary program '%s' not found" + : status == INT_MAX + ? "subsidiary program '%s' failed" + : "subsidiary program '%s' failed (exit status %d)"), + pr_program, status); + } + + outfile = 0; +} + +/* Compare two lines (typically one from each input file) + according to the command line options. + For efficiency, this is invoked only when the lines do not match exactly + but an option like -i might cause us to ignore the difference. + Return nonzero if the lines differ. */ + +bool +lines_differ (char const *s1, char const *s2) +{ + register char const *t1 = s1; + register char const *t2 = s2; + size_t column = 0; + + while (1) + { + register unsigned char c1 = *t1++; + register unsigned char c2 = *t2++; + + /* Test for exact char equality first, since it's a common case. */ + if (c1 != c2) + { + switch (ignore_white_space) + { + case IGNORE_ALL_SPACE: + /* For -w, just skip past any white space. */ + while (isspace (c1) && c1 != '\n') c1 = *t1++; + while (isspace (c2) && c2 != '\n') c2 = *t2++; + break; + + case IGNORE_SPACE_CHANGE: + /* For -b, advance past any sequence of white space in + line 1 and consider it just one space, or nothing at + all if it is at the end of the line. */ + if (isspace (c1)) + { + while (c1 != '\n') + { + c1 = *t1++; + if (! isspace (c1)) + { + --t1; + c1 = ' '; + break; + } + } + } + + /* Likewise for line 2. */ + if (isspace (c2)) + { + while (c2 != '\n') + { + c2 = *t2++; + if (! isspace (c2)) + { + --t2; + c2 = ' '; + break; + } + } + } + + if (c1 != c2) + { + /* If we went too far when doing the simple test + for equality, go back to the first non-white-space + character in both sides and try again. */ + if (c2 == ' ' && c1 != '\n' + && s1 + 1 < t1 + && isspace ((unsigned char) t1[-2])) + { + --t1; + continue; + } + if (c1 == ' ' && c2 != '\n' + && s2 + 1 < t2 + && isspace ((unsigned char) t2[-2])) + { + --t2; + continue; + } + } + + break; + + case IGNORE_TRAILING_SPACE: + case IGNORE_TAB_EXPANSION_AND_TRAILING_SPACE: + if (isspace (c1) && isspace (c2)) + { + unsigned char c; + if (c1 != '\n') + { + char const *p = t1; + while ((c = *p) != '\n' && isspace (c)) + ++p; + if (c != '\n') + break; + } + if (c2 != '\n') + { + char const *p = t2; + while ((c = *p) != '\n' && isspace (c)) + ++p; + if (c != '\n') + break; + } + /* Both lines have nothing but whitespace left. */ + return false; + } + if (ignore_white_space == IGNORE_TRAILING_SPACE) + break; + /* Fall through. */ + case IGNORE_TAB_EXPANSION: + if ((c1 == ' ' && c2 == '\t') + || (c1 == '\t' && c2 == ' ')) + { + size_t column2 = column; + for (;; c1 = *t1++) + { + if (c1 == ' ') + column++; + else if (c1 == '\t') + column += tabsize - column % tabsize; + else + break; + } + for (;; c2 = *t2++) + { + if (c2 == ' ') + column2++; + else if (c2 == '\t') + column2 += tabsize - column2 % tabsize; + else + break; + } + if (column != column2) + return true; + } + break; + + case IGNORE_NO_WHITE_SPACE: + break; + } + + /* Lowercase all letters if -i is specified. */ + + if (ignore_case) + { + c1 = tolower (c1); + c2 = tolower (c2); + } + + if (c1 != c2) + break; + } + if (c1 == '\n') + return false; + + column += c1 == '\t' ? tabsize - column % tabsize : 1; + } + + return true; +} + +/* Find the consecutive changes at the start of the script START. + Return the last link before the first gap. */ + +struct change * _GL_ATTRIBUTE_CONST +find_change (struct change *start) +{ + return start; +} + +struct change * _GL_ATTRIBUTE_CONST +find_reverse_change (struct change *start) +{ + return start; +} + +/* Divide SCRIPT into pieces by calling HUNKFUN and + print each piece with PRINTFUN. + Both functions take one arg, an edit script. + + HUNKFUN is called with the tail of the script + and returns the last link that belongs together with the start + of the tail. + + PRINTFUN takes a subscript which belongs together (with a null + link at the end) and prints it. */ + +void +print_script (struct change *script, + struct change * (*hunkfun) (struct change *), + void (*printfun) (struct change *)) +{ + struct change *next = script; + + while (next) + { + struct change *this, *end; + + /* Find a set of changes that belong together. */ + this = next; + end = (*hunkfun) (next); + + /* Disconnect them from the rest of the changes, + making them a hunk, and remember the rest for next iteration. */ + next = end->link; + end->link = 0; +#ifdef DEBUG + debug_script (this); +#endif + + /* Print this hunk. */ + (*printfun) (this); + + /* Reconnect the script so it will all be freed properly. */ + end->link = next; + } +} + +/* Print the text of a single line LINE, + flagging it with the characters in LINE_FLAG (which say whether + the line is inserted, deleted, changed, etc.). LINE_FLAG must not + end in a blank, unless it is a single blank. */ + +void +print_1_line (char const *line_flag, char const *const *line) +{ + print_1_line_nl (line_flag, line, false); +} + +/* Print the text of a single line LINE, + flagging it with the characters in LINE_FLAG (which say whether + the line is inserted, deleted, changed, etc.). LINE_FLAG must not + end in a blank, unless it is a single blank. If SKIP_NL is set, then + the final '\n' is not printed. */ + +void +print_1_line_nl (char const *line_flag, char const *const *line, bool skip_nl) +{ + char const *base = line[0], *limit = line[1]; /* Help the compiler. */ + FILE *out = outfile; /* Help the compiler some more. */ + char const *flag_format = 0; + + /* If -T was specified, use a Tab between the line-flag and the text. + Otherwise use a Space (as Unix diff does). + Print neither space nor tab if line-flags are empty. + But omit trailing blanks if requested. */ + + if (line_flag && *line_flag) + { + char const *flag_format_1 = flag_format = initial_tab ? "%s\t" : "%s "; + char const *line_flag_1 = line_flag; + + if (suppress_blank_empty && **line == '\n') + { + flag_format_1 = "%s"; + + /* This hack to omit trailing blanks takes advantage of the + fact that the only way that LINE_FLAG can end in a blank + is when LINE_FLAG consists of a single blank. */ + line_flag_1 += *line_flag_1 == ' '; + } + + fprintf (out, flag_format_1, line_flag_1); + } + + output_1_line (base, limit - (skip_nl && limit[-1] == '\n'), flag_format, line_flag); + + if ((!line_flag || line_flag[0]) && limit[-1] != '\n') + { + set_color_context (RESET_CONTEXT); + fprintf (out, "\n\\ %s\n", _("No newline at end of file")); + } +} + +/* Output a line from BASE up to LIMIT. + With -t, expand white space characters to spaces, and if FLAG_FORMAT + is nonzero, output it with argument LINE_FLAG after every + internal carriage return, so that tab stops continue to line up. */ + +void +output_1_line (char const *base, char const *limit, char const *flag_format, + char const *line_flag) +{ + const size_t MAX_CHUNK = 1024; + if (!expand_tabs) + { + size_t left = limit - base; + while (left) + { + size_t to_write = MIN (left, MAX_CHUNK); + size_t written = fwrite (base, sizeof (char), to_write, outfile); + if (written < to_write) + return; + base += written; + left -= written; + process_signals (); + } + } + else + { + register FILE *out = outfile; + register unsigned char c; + register char const *t = base; + register size_t column = 0; + size_t tab_size = tabsize; + size_t counter_proc_signals = 0; + + while (t < limit) + { + counter_proc_signals++; + if (counter_proc_signals == MAX_CHUNK) + { + process_signals (); + counter_proc_signals = 0; + } + + switch ((c = *t++)) + { + case '\t': + { + size_t spaces = tab_size - column % tab_size; + column += spaces; + do + putc (' ', out); + while (--spaces); + } + break; + + case '\r': + putc (c, out); + if (flag_format && t < limit && *t != '\n') + fprintf (out, flag_format, line_flag); + column = 0; + break; + + case '\b': + if (column == 0) + continue; + column--; + putc (c, out); + break; + + default: + column += isprint (c) != 0; + putc (c, out); + break; + } + } + } +} + +enum indicator_no + { + C_LEFT, C_RIGHT, C_END, C_RESET, C_HEADER, C_ADD, C_DELETE, C_LINE + }; + +static void +put_indicator (const struct bin_str *ind) +{ + fwrite (ind->string, ind->len, 1, outfile); +} + +static enum color_context last_context = RESET_CONTEXT; + +void +set_color_context (enum color_context color_context) +{ + if (color_context != RESET_CONTEXT) + process_signals (); + if (colors_enabled && last_context != color_context) + { + put_indicator (&color_indicator[C_LEFT]); + switch (color_context) + { + case HEADER_CONTEXT: + put_indicator (&color_indicator[C_HEADER]); + break; + + case LINE_NUMBER_CONTEXT: + put_indicator (&color_indicator[C_LINE]); + break; + + case ADD_CONTEXT: + put_indicator (&color_indicator[C_ADD]); + break; + + case DELETE_CONTEXT: + put_indicator (&color_indicator[C_DELETE]); + break; + + case RESET_CONTEXT: + put_indicator (&color_indicator[C_RESET]); + break; + + default: + abort (); + } + put_indicator (&color_indicator[C_RIGHT]); + last_context = color_context; + } +} + + +char const change_letter[] = { 0, 'd', 'a', 'c' }; + +/* Translate an internal line number (an index into diff's table of lines) + into an actual line number in the input file. + The internal line number is I. FILE points to the data on the file. + + Internal line numbers count from 0 starting after the prefix. + Actual line numbers count from 1 within the entire file. */ + +lin _GL_ATTRIBUTE_PURE +translate_line_number (struct file_data const *file, lin i) +{ + return i + file->prefix_lines + 1; +} + +/* Translate a line number range. This is always done for printing, + so for convenience translate to long int rather than lin, so that the + caller can use printf with "%ld" without casting. */ + +void +translate_range (struct file_data const *file, + lin a, lin b, + long int *aptr, long int *bptr) +{ + *aptr = translate_line_number (file, a - 1) + 1; + *bptr = translate_line_number (file, b + 1) - 1; +} + +/* Print a pair of line numbers with SEPCHAR, translated for file FILE. + If the two numbers are identical, print just one number. + + Args A and B are internal line numbers. + We print the translated (real) line numbers. */ + +void +print_number_range (char sepchar, struct file_data *file, lin a, lin b) +{ + long int trans_a, trans_b; + translate_range (file, a, b, &trans_a, &trans_b); + + /* Note: we can have B < A in the case of a range of no lines. + In this case, we should print the line number before the range, + which is B. */ + if (trans_b > trans_a) + fprintf (outfile, "%ld%c%ld", trans_a, sepchar, trans_b); + else + fprintf (outfile, "%ld", trans_b); +} + +/* Look at a hunk of edit script and report the range of lines in each file + that it applies to. HUNK is the start of the hunk, which is a chain + of 'struct change'. The first and last line numbers of file 0 are stored in + *FIRST0 and *LAST0, and likewise for file 1 in *FIRST1 and *LAST1. + Note that these are internal line numbers that count from 0. + + If no lines from file 0 are deleted, then FIRST0 is LAST0+1. + + Return UNCHANGED if only ignorable lines are inserted or deleted, + OLD if lines of file 0 are deleted, + NEW if lines of file 1 are inserted, + and CHANGED if both kinds of changes are found. */ + +enum changes +analyze_hunk (struct change *hunk, + lin *first0, lin *last0, + lin *first1, lin *last1) +{ + struct change *next; + lin l0, l1; + lin show_from, show_to; + lin i; + bool trivial = ignore_blank_lines || ignore_regexp.fastmap; + size_t trivial_length = ignore_blank_lines - 1; + /* If 0, ignore zero-length lines; + if SIZE_MAX, do not ignore lines just because of their length. */ + + bool skip_white_space = + ignore_blank_lines && IGNORE_TRAILING_SPACE <= ignore_white_space; + bool skip_leading_white_space = + skip_white_space && IGNORE_SPACE_CHANGE <= ignore_white_space; + + char const * const *linbuf0 = files[0].linbuf; /* Help the compiler. */ + char const * const *linbuf1 = files[1].linbuf; + + show_from = show_to = 0; + + *first0 = hunk->line0; + *first1 = hunk->line1; + + next = hunk; + do + { + l0 = next->line0 + next->deleted - 1; + l1 = next->line1 + next->inserted - 1; + show_from += next->deleted; + show_to += next->inserted; + + for (i = next->line0; i <= l0 && trivial; i++) + { + char const *line = linbuf0[i]; + char const *lastbyte = linbuf0[i + 1] - 1; + char const *newline = lastbyte + (*lastbyte != '\n'); + size_t len = newline - line; + char const *p = line; + if (skip_white_space) + for (; *p != '\n'; p++) + if (! isspace ((unsigned char) *p)) + { + if (! skip_leading_white_space) + p = line; + break; + } + if (newline - p != trivial_length + && (! ignore_regexp.fastmap + || re_search (&ignore_regexp, line, len, 0, len, 0) < 0)) + trivial = 0; + } + + for (i = next->line1; i <= l1 && trivial; i++) + { + char const *line = linbuf1[i]; + char const *lastbyte = linbuf1[i + 1] - 1; + char const *newline = lastbyte + (*lastbyte != '\n'); + size_t len = newline - line; + char const *p = line; + if (skip_white_space) + for (; *p != '\n'; p++) + if (! isspace ((unsigned char) *p)) + { + if (! skip_leading_white_space) + p = line; + break; + } + if (newline - p != trivial_length + && (! ignore_regexp.fastmap + || re_search (&ignore_regexp, line, len, 0, len, 0) < 0)) + trivial = 0; + } + } + while ((next = next->link) != 0); + + *last0 = l0; + *last1 = l1; + + /* If all inserted or deleted lines are ignorable, + tell the caller to ignore this hunk. */ + + if (trivial) + return UNCHANGED; + + return (show_from ? OLD : UNCHANGED) | (show_to ? NEW : UNCHANGED); +} + +/* Concatenate three strings, returning a newly malloc'd string. */ + +char * +concat (char const *s1, char const *s2, char const *s3) +{ + char *new = xmalloc (strlen (s1) + strlen (s2) + strlen (s3) + 1); + sprintf (new, "%s%s%s", s1, s2, s3); + return new; +} + +/* Yield a new block of SIZE bytes, initialized to zero. */ + +void * +zalloc (size_t size) +{ + void *p = xmalloc (size); + memset (p, 0, size); + return p; +} + +void +debug_script (struct change *sp) +{ + fflush (stdout); + + for (; sp; sp = sp->link) + { + long int line0 = sp->line0; + long int line1 = sp->line1; + long int deleted = sp->deleted; + long int inserted = sp->inserted; + fprintf (stderr, "%3ld %3ld delete %ld insert %ld\n", + line0, line1, deleted, inserted); + } + + fflush (stderr); +} |