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Diffstat (limited to 'src/util.c')
| -rw-r--r-- | src/util.c | 788 |
1 files changed, 788 insertions, 0 deletions
diff --git a/src/util.c b/src/util.c new file mode 100644 index 0000000..3be03e9 --- /dev/null +++ b/src/util.c @@ -0,0 +1,788 @@ +/* Support routines for GNU DIFF. + + Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006, 2009-2010 + 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 <dirname.h> +#include <error.h> +#include <sh-quote.h> +#include <xalloc.h> + +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; + } +} + +/* 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. */ + +static char const *current_name0; +static char const *current_name1; +static bool currently_recursive; + +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 || HAVE_WORKING_VFORK +static pid_t pr_pid; +#endif + +void +begin_output (void) +{ + char *name; + + if (outfile != 0) + return; + + /* Construct the header of this piece of diff. */ + name = xmalloc (strlen (current_name0) + strlen (current_name1) + + strlen (switch_string) + 7); + + /* 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. */ + sprintf (name, "diff%s %s %s", switch_string, current_name0, current_name1); + + if (paginate) + { + if (fflush (stdout) != 0) + pfatal_with_name (_("write failed")); + + /* Make OUTFILE a pipe to a subsidiary `pr'. */ + { +#if HAVE_WORKING_FORK || HAVE_WORKING_VFORK + int pipes[2]; + + if (pipe (pipes) != 0) + pfatal_with_name ("pipe"); + + pr_pid = vfork (); + 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]); + } + + execl (pr_program, pr_program, "-h", name, (char *) 0); + _exit (errno == ENOENT ? 127 : 126); + } + else + { + close (pipes[0]); + outfile = fdopen (pipes[1], "w"); + if (!outfile) + pfatal_with_name ("fdopen"); + } +#else + char *command = xmalloc (sizeof pr_program - 1 + 7 + + shell_quote_length (name) + 1); + char *p; + sprintf (command, "%s -f -h ", pr_program); + p = command + sizeof pr_program - 1 + 7; + p = shell_quote_copy (p, name); + *p = 0; + errno = 0; + outfile = popen (command, "w"); + if (!outfile) + pfatal_with_name (command); + free (command); +#endif + } + } + else + { + + /* If -l was not specified, output the diff straight to `stdout'. */ + + outfile = stdout; + + /* 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, false); + break; + + case OUTPUT_UNIFIED: + print_context_header (files, true); + break; + + default: + break; + } +} + +/* 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 || HAVE_WORKING_VFORK) + 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_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 * +find_change (struct change *start) +{ + return start; +} + +struct change * +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) +{ + 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, flag_format, line_flag); + + if ((!line_flag || line_flag[0]) && limit[-1] != '\n') + 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) +{ + if (!expand_tabs) + fwrite (base, sizeof (char), limit - base, outfile); + else + { + register FILE *out = outfile; + register unsigned char c; + register char const *t = base; + register size_t column = 0; + size_t tab_size = tabsize; + + while (t < limit) + 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; + } + } +} + +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 +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_leading_white_space = + (ignore_blank_lines && 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 *newline = linbuf0[i + 1] - 1; + size_t len = newline - line; + char const *p = line; + if (skip_leading_white_space) + while (isspace ((unsigned char) *p) && *p != '\n') + p++; + 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 *newline = linbuf1[i + 1] - 1; + size_t len = newline - line; + char const *p = line; + if (skip_leading_white_space) + while (isspace ((unsigned char) *p) && *p != '\n') + p++; + 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; +} + +/* Yield the newly malloc'd pathname + of the file in DIR whose filename is FILE. */ + +char * +dir_file_pathname (char const *dir, char const *file) +{ + char const *base = last_component (dir); + size_t baselen = base_len (base); + bool omit_slash = baselen == 0 || base[baselen - 1] == '/'; + return concat (dir, "/" + omit_slash, file); +} + +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); +} |