/*
* $Id: readtags.c 592 2007-07-31 03:30:41Z dhiebert $
*
* Copyright (c) 1996-2003, Darren Hiebert
*
* This source code is released into the public domain.
*
* This module contains functions for reading tag files.
*/
/*
* INCLUDE FILES
*/
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#include <errno.h>
#include <sys/types.h> /* to declare off_t */
#include "readtags.h"
/*
* MACROS
*/
#define TAB '\t'
/*
* DATA DECLARATIONS
*/
typedef struct {
size_t size;
char *buffer;
} vstring;
/* Information about current tag file */
struct sTagFile {
/* has the file been opened and this structure initialized? */
short initialized;
/* format of tag file */
short format;
/* how is the tag file sorted? */
sortType sortMethod;
/* pointer to file structure */
FILE* fp;
/* file position of first character of `line' */
off_t pos;
/* size of tag file in seekable positions */
off_t size;
/* last line read */
vstring line;
/* name of tag in last line read */
vstring name;
/* defines tag search state */
struct {
/* file position of last match for tag */
off_t pos;
/* name of tag last searched for */
char *name;
/* length of name for partial matches */
size_t nameLength;
/* peforming partial match */
short partial;
/* ignoring case */
short ignorecase;
} search;
/* miscellaneous extension fields */
struct {
/* number of entries in `list' */
unsigned short max;
/* list of key value pairs */
tagExtensionField *list;
} fields;
/* buffers to be freed at close */
struct {
/* name of program author */
char *author;
/* name of program */
char *name;
/* URL of distribution */
char *url;
/* program version */
char *version;
} program;
};
/*
* DATA DEFINITIONS
*/
const char *const EmptyString = "";
const char *const PseudoTagPrefix = "!_";
/*
* FUNCTION DEFINITIONS
*/
/*
* Compare two strings, ignoring case.
* Return 0 for match, < 0 for smaller, > 0 for bigger
* Make sure case is folded to uppercase in comparison (like for 'sort -f')
* This makes a difference when one of the chars lies between upper and lower
* ie. one of the chars [ \ ] ^ _ ` for ascii. (The '_' in particular !)
*/
static int struppercmp (const char *s1, const char *s2)
{
int result;
do
{
result = toupper ((int) *s1) - toupper ((int) *s2);
} while (result == 0 && *s1++ != '\0' && *s2++ != '\0');
return result;
}
static int strnuppercmp (const char *s1, const char *s2, size_t n)
{
int result;
do
{
result = toupper ((int) *s1) - toupper ((int) *s2);
} while (result == 0 && --n > 0 && *s1++ != '\0' && *s2++ != '\0');
return result;
}
static int growString (vstring *s)
{
int result = 0;
size_t newLength;
char *newLine;
if (s->size == 0)
{
newLength = 128;
newLine = (char*) malloc (newLength);
*newLine = '\0';
}
else
{
newLength = 2 * s->size;
newLine = (char*) realloc (s->buffer, newLength);
}
if (newLine == NULL)
perror ("string too large");
else
{
s->buffer = newLine;
s->size = newLength;
result = 1;
}
return result;
}
/* Copy name of tag out of tag line */
static void copyName (tagFile *const file)
{
size_t length;
const char *end = strchr (file->line.buffer, '\t');
if (end == NULL)
{
end = strchr (file->line.buffer, '\n');
if (end == NULL)
end = strchr (file->line.buffer, '\r');
}
if (end != NULL)
length = end - file->line.buffer;
else
length = strlen (file->line.buffer);
while (length >= file->name.size)
growString (&file->name);
strncpy (file->name.buffer, file->line.buffer, length);
file->name.buffer [length] = '\0';
}
static int readTagLineRaw (tagFile *const file)
{
int result = 1;
int reReadLine;
/* If reading the line places any character other than a null or a
* newline at the last character position in the buffer (one less than
* the buffer size), then we must resize the buffer and reattempt to read
* the line.
*/
do
{
char *const pLastChar = file->line.buffer + file->line.size - 2;
char *line;
file->pos = ftell (file->fp);
reReadLine = 0;
*pLastChar = '\0';
line = fgets (file->line.buffer, (int) file->line.size, file->fp);
if (line == NULL)
{
/* read error */
if (! feof (file->fp))
perror ("readTagLine");
result = 0;
}
else if (*pLastChar != '\0' &&
*pLastChar != '\n' && *pLastChar != '\r')
{
/* buffer overflow */
growString (&file->line);
fseek (file->fp, file->pos, SEEK_SET);
reReadLine = 1;
}
else
{
size_t i = strlen (file->line.buffer);
while (i > 0 &&
(file->line.buffer [i - 1] == '\n' || file->line.buffer [i - 1] == '\r'))
{
file->line.buffer [i - 1] = '\0';
--i;
}
}
} while (reReadLine && result);
if (result)
copyName (file);
return result;
}
static int readTagLine (tagFile *const file)
{
int result;
do
{
result = readTagLineRaw (file);
} while (result && *file->name.buffer == '\0');
return result;
}
static tagResult growFields (tagFile *const file)
{
tagResult result = TagFailure;
unsigned short newCount = (unsigned short) 2 * file->fields.max;
tagExtensionField *newFields = (tagExtensionField*)
realloc (file->fields.list, newCount * sizeof (tagExtensionField));
if (newFields == NULL)
perror ("too many extension fields");
else
{
file->fields.list = newFields;
file->fields.max = newCount;
result = TagSuccess;
}
return result;
}
static void parseExtensionFields (tagFile *const file, tagEntry *const entry,
char *const string)
{
char *p = string;
while (p != NULL && *p != '\0')
{
while (*p == TAB)
*p++ = '\0';
if (*p != '\0')
{
char *colon;
char *field = p;
p = strchr (p, TAB);
if (p != NULL)
*p++ = '\0';
colon = strchr (field, ':');
if (colon == NULL)
entry->kind = field;
else
{
const char *key = field;
const char *value = colon + 1;
*colon = '\0';
if (strcmp (key, "kind") == 0)
entry->kind = value;
else if (strcmp (key, "file") == 0)
entry->fileScope = 1;
else if (strcmp (key, "line") == 0)
entry->address.lineNumber = atol (value);
else
{
if (entry->fields.count == file->fields.max)
growFields (file);
file->fields.list [entry->fields.count].key = key;
file->fields.list [entry->fields.count].value = value;
++entry->fields.count;
}
}
}
}
}
static void parseTagLine (tagFile *file, tagEntry *const entry)
{
int i;
char *p = file->line.buffer;
char *tab = strchr (p, TAB);
entry->fields.list = NULL;
entry->fields.count = 0;
entry->kind = NULL;
entry->fileScope = 0;
entry->name = p;
if (tab != NULL)
{
*tab = '\0';
p = tab + 1;
entry->file = p;
tab = strchr (p, TAB);
if (tab != NULL)
{
int fieldsPresent;
*tab = '\0';
p = tab + 1;
if (*p == '/' || *p == '?')
{
/* parse pattern */
int delimiter = *(unsigned char*) p;
entry->address.lineNumber = 0;
entry->address.pattern = p;
do
{
p = strchr (p + 1, delimiter);
} while (p != NULL && *(p - 1) == '\\');
if (p == NULL)
{
/* invalid pattern */
}
else
++p;
}
else if (isdigit ((int) *(unsigned char*) p))
{
/* parse line number */
entry->address.pattern = p;
entry->address.lineNumber = atol (p);
while (isdigit ((int) *(unsigned char*) p))
++p;
}
else
{
/* invalid pattern */
}
fieldsPresent = (strncmp (p, ";\"", 2) == 0);
*p = '\0';
if (fieldsPresent)
parseExtensionFields (file, entry, p + 2);
}
}
if (entry->fields.count > 0)
entry->fields.list = file->fields.list;
for (i = entry->fields.count ; i < file->fields.max ; ++i)
{
file->fields.list [i].key = NULL;
file->fields.list [i].value = NULL;
}
}
static char *duplicate (const char *str)
{
char *result = NULL;
if (str != NULL)
{
result = strdup (str);
if (result == NULL)
perror (NULL);
}
return result;
}
static void readPseudoTags (tagFile *const file, tagFileInfo *const info)
{
fpos_t startOfLine;
const size_t prefixLength = strlen (PseudoTagPrefix);
if (info != NULL)
{
info->file.format = 1;
info->file.sort = TAG_UNSORTED;
info->program.author = NULL;
info->program.name = NULL;
info->program.url = NULL;
info->program.version = NULL;
}
while (1)
{
fgetpos (file->fp, &startOfLine);
if (! readTagLine (file))
break;
if (strncmp (file->line.buffer, PseudoTagPrefix, prefixLength) != 0)
break;
else
{
tagEntry entry;
const char *key, *value;
parseTagLine (file, &entry);
key = entry.name + prefixLength;
value = entry.file;
if (strcmp (key, "TAG_FILE_SORTED") == 0)
file->sortMethod = (sortType) atoi (value);
else if (strcmp (key, "TAG_FILE_FORMAT") == 0)
file->format = (short) atoi (value);
else if (strcmp (key, "TAG_PROGRAM_AUTHOR") == 0)
file->program.author = duplicate (value);
else if (strcmp (key, "TAG_PROGRAM_NAME") == 0)
file->program.name = duplicate (value);
else if (strcmp (key, "TAG_PROGRAM_URL") == 0)
file->program.url = duplicate (value);
else if (strcmp (key, "TAG_PROGRAM_VERSION") == 0)
file->program.version = duplicate (value);
if (info != NULL)
{
info->file.format = file->format;
info->file.sort = file->sortMethod;
info->program.author = file->program.author;
info->program.name = file->program.name;
info->program.url = file->program.url;
info->program.version = file->program.version;
}
}
}
fsetpos (file->fp, &startOfLine);
}
static void gotoFirstLogicalTag (tagFile *const file)
{
fpos_t startOfLine;
const size_t prefixLength = strlen (PseudoTagPrefix);
rewind (file->fp);
while (1)
{
fgetpos (file->fp, &startOfLine);
if (! readTagLine (file))
break;
if (strncmp (file->line.buffer, PseudoTagPrefix, prefixLength) != 0)
break;
}
fsetpos (file->fp, &startOfLine);
}
static tagFile *initialize (const char *const filePath, tagFileInfo *const info)
{
tagFile *result = (tagFile*) calloc ((size_t) 1, sizeof (tagFile));
if (result != NULL)
{
growString (&result->line);
growString (&result->name);
result->fields.max = 20;
result->fields.list = (tagExtensionField*) calloc (
result->fields.max, sizeof (tagExtensionField));
result->fp = fopen (filePath, "r");
if (result->fp == NULL)
{
free (result);
result = NULL;
info->status.error_number = errno;
}
else
{
fseek (result->fp, 0, SEEK_END);
result->size = ftell (result->fp);
rewind (result->fp);
readPseudoTags (result, info);
info->status.opened = 1;
result->initialized = 1;
}
}
return result;
}
static void terminate (tagFile *const file)
{
fclose (file->fp);
free (file->line.buffer);
free (file->name.buffer);
free (file->fields.list);
if (file->program.author != NULL)
free (file->program.author);
if (file->program.name != NULL)
free (file->program.name);
if (file->program.url != NULL)
free (file->program.url);
if (file->program.version != NULL)
free (file->program.version);
if (file->search.name != NULL)
free (file->search.name);
memset (file, 0, sizeof (tagFile));
free (file);
}
static tagResult readNext (tagFile *const file, tagEntry *const entry)
{
tagResult result;
if (file == NULL || ! file->initialized)
result = TagFailure;
else if (! readTagLine (file))
result = TagFailure;
else
{
if (entry != NULL)
parseTagLine (file, entry);
result = TagSuccess;
}
return result;
}
static const char *readFieldValue (
const tagEntry *const entry, const char *const key)
{
const char *result = NULL;
int i;
if (strcmp (key, "kind") == 0)
result = entry->kind;
else if (strcmp (key, "file") == 0)
result = EmptyString;
else for (i = 0 ; i < entry->fields.count && result == NULL ; ++i)
if (strcmp (entry->fields.list [i].key, key) == 0)
result = entry->fields.list [i].value;
return result;
}
static int readTagLineSeek (tagFile *const file, const off_t pos)
{
int result = 0;
if (fseek (file->fp, pos, SEEK_SET) == 0)
{
result = readTagLine (file); /* read probable partial line */
if (pos > 0 && result)
result = readTagLine (file); /* read complete line */
}
return result;
}
static int nameComparison (tagFile *const file)
{
int result;
if (file->search.ignorecase)
{
if (file->search.partial)
result = strnuppercmp (file->search.name, file->name.buffer,
file->search.nameLength);
else
result = struppercmp (file->search.name, file->name.buffer);
}
else
{
if (file->search.partial)
result = strncmp (file->search.name, file->name.buffer,
file->search.nameLength);
else
result = strcmp (file->search.name, file->name.buffer);
}
return result;
}
static void findFirstNonMatchBefore (tagFile *const file)
{
#define JUMP_BACK 512
int more_lines;
int comp;
off_t start = file->pos;
off_t pos = start;
do
{
if (pos < (off_t) JUMP_BACK)
pos = 0;
else
pos = pos - JUMP_BACK;
more_lines = readTagLineSeek (file, pos);
comp = nameComparison (file);
} while (more_lines && comp == 0 && pos > 0 && pos < start);
}
static tagResult findFirstMatchBefore (tagFile *const file)
{
tagResult result = TagFailure;
int more_lines;
off_t start = file->pos;
findFirstNonMatchBefore (file);
do
{
more_lines = readTagLine (file);
if (nameComparison (file) == 0)
result = TagSuccess;
} while (more_lines && result != TagSuccess && file->pos < start);
return result;
}
static tagResult findBinary (tagFile *const file)
{
tagResult result = TagFailure;
off_t lower_limit = 0;
off_t upper_limit = file->size;
off_t last_pos = 0;
off_t pos = upper_limit / 2;
while (result != TagSuccess)
{
if (! readTagLineSeek (file, pos))
{
/* in case we fell off end of file */
result = findFirstMatchBefore (file);
break;
}
else if (pos == last_pos)
{
/* prevent infinite loop if we backed up to beginning of file */
break;
}
else
{
const int comp = nameComparison (file);
last_pos = pos;
if (comp < 0)
{
upper_limit = pos;
pos = lower_limit + ((upper_limit - lower_limit) / 2);
}
else if (comp > 0)
{
lower_limit = pos;
pos = lower_limit + ((upper_limit - lower_limit) / 2);
}
else if (pos == 0)
result = TagSuccess;
else
result = findFirstMatchBefore (file);
}
}
return result;
}
static tagResult findSequential (tagFile *const file)
{
tagResult result = TagFailure;
if (file->initialized)
{
while (result == TagFailure && readTagLine (file))
{
if (nameComparison (file) == 0)
result = TagSuccess;
}
}
return result;
}
static tagResult find (tagFile *const file, tagEntry *const entry,
const char *const name, const int options)
{
tagResult result;
if (file->search.name != NULL)
free (file->search.name);
file->search.name = duplicate (name);
file->search.nameLength = strlen (name);
file->search.partial = (options & TAG_PARTIALMATCH) != 0;
file->search.ignorecase = (options & TAG_IGNORECASE) != 0;
fseek (file->fp, 0, SEEK_END);
file->size = ftell (file->fp);
rewind (file->fp);
if ((file->sortMethod == TAG_SORTED && !file->search.ignorecase) ||
(file->sortMethod == TAG_FOLDSORTED && file->search.ignorecase))
{
#ifdef DEBUG
printf ("<performing binary search>\n");
#endif
result = findBinary (file);
}
else
{
#ifdef DEBUG
printf ("<performing sequential search>\n");
#endif
result = findSequential (file);
}
if (result != TagSuccess)
file->search.pos = file->size;
else
{
file->search.pos = file->pos;
if (entry != NULL)
parseTagLine (file, entry);
}
return result;
}
static tagResult findNext (tagFile *const file, tagEntry *const entry)
{
tagResult result;
if ((file->sortMethod == TAG_SORTED && !file->search.ignorecase) ||
(file->sortMethod == TAG_FOLDSORTED && file->search.ignorecase))
{
result = tagsNext (file, entry);
if (result == TagSuccess && nameComparison (file) != 0)
result = TagFailure;
}
else
{
result = findSequential (file);
if (result == TagSuccess && entry != NULL)
parseTagLine (file, entry);
}
return result;
}
/*
* EXTERNAL INTERFACE
*/
extern tagFile *tagsOpen (const char *const filePath, tagFileInfo *const info)
{
return initialize (filePath, info);
}
extern tagResult tagsSetSortType (tagFile *const file, const sortType type)
{
tagResult result = TagFailure;
if (file != NULL && file->initialized)
{
file->sortMethod = type;
result = TagSuccess;
}
return result;
}
extern tagResult tagsFirst (tagFile *const file, tagEntry *const entry)
{
tagResult result = TagFailure;
if (file != NULL && file->initialized)
{
gotoFirstLogicalTag (file);
result = readNext (file, entry);
}
return result;
}
extern tagResult tagsNext (tagFile *const file, tagEntry *const entry)
{
tagResult result = TagFailure;
if (file != NULL && file->initialized)
result = readNext (file, entry);
return result;
}
extern const char *tagsField (const tagEntry *const entry, const char *const key)
{
const char *result = NULL;
if (entry != NULL)
result = readFieldValue (entry, key);
return result;
}
extern tagResult tagsFind (tagFile *const file, tagEntry *const entry,
const char *const name, const int options)
{
tagResult result = TagFailure;
if (file != NULL && file->initialized)
result = find (file, entry, name, options);
return result;
}
extern tagResult tagsFindNext (tagFile *const file, tagEntry *const entry)
{
tagResult result = TagFailure;
if (file != NULL && file->initialized)
result = findNext (file, entry);
return result;
}
extern tagResult tagsClose (tagFile *const file)
{
tagResult result = TagFailure;
if (file != NULL && file->initialized)
{
terminate (file);
result = TagSuccess;
}
return result;
}
/*
* TEST FRAMEWORK
*/
#ifdef READTAGS_MAIN
static const char *TagFileName = "tags";
static const char *ProgramName;
static int extensionFields;
static int SortOverride;
static sortType SortMethod;
static void printTag (const tagEntry *entry)
{
int i;
int first = 1;
const char* separator = ";\"";
const char* const empty = "";
/* "sep" returns a value only the first time it is evaluated */
#define sep (first ? (first = 0, separator) : empty)
printf ("%s\t%s\t%s",
entry->name, entry->file, entry->address.pattern);
if (extensionFields)
{
if (entry->kind != NULL && entry->kind [0] != '\0')
printf ("%s\tkind:%s", sep, entry->kind);
if (entry->fileScope)
printf ("%s\tfile:", sep);
#if 0
if (entry->address.lineNumber > 0)
printf ("%s\tline:%lu", sep, entry->address.lineNumber);
#endif
for (i = 0 ; i < entry->fields.count ; ++i)
printf ("%s\t%s:%s", sep, entry->fields.list [i].key,
entry->fields.list [i].value);
}
putchar ('\n');
#undef sep
}
static void findTag (const char *const name, const int options)
{
tagFileInfo info;
tagEntry entry;
tagFile *const file = tagsOpen (TagFileName, &info);
if (file == NULL)
{
fprintf (stderr, "%s: cannot open tag file: %s: %s\n",
ProgramName, strerror (info.status.error_number), name);
exit (1);
}
else
{
if (SortOverride)
tagsSetSortType (file, SortMethod);
if (tagsFind (file, &entry, name, options) == TagSuccess)
{
do
{
printTag (&entry);
} while (tagsFindNext (file, &entry) == TagSuccess);
}
tagsClose (file);
}
}
static void listTags (void)
{
tagFileInfo info;
tagEntry entry;
tagFile *const file = tagsOpen (TagFileName, &info);
if (file == NULL)
{
fprintf (stderr, "%s: cannot open tag file: %s: %s\n",
ProgramName, strerror (info.status.error_number), TagFileName);
exit (1);
}
else
{
while (tagsNext (file, &entry) == TagSuccess)
printTag (&entry);
tagsClose (file);
}
}
const char *const Usage =
"Find tag file entries matching specified names.\n\n"
"Usage: %s [-ilp] [-s[0|1]] [-t file] [name(s)]\n\n"
"Options:\n"
" -e Include extension fields in output.\n"
" -i Perform case-insensitive matching.\n"
" -l List all tags.\n"
" -p Perform partial matching.\n"
" -s[0|1|2] Override sort detection of tag file.\n"
" -t file Use specified tag file (default: \"tags\").\n"
"Note that options are acted upon as encountered, so order is significant.\n";
extern int main (int argc, char **argv)
{
int options = 0;
int actionSupplied = 0;
int i;
ProgramName = argv [0];
if (argc == 1)
{
fprintf (stderr, Usage, ProgramName);
exit (1);
}
for (i = 1 ; i < argc ; ++i)
{
const char *const arg = argv [i];
if (arg [0] != '-')
{
findTag (arg, options);
actionSupplied = 1;
}
else
{
size_t j;
for (j = 1 ; arg [j] != '\0' ; ++j)
{
switch (arg [j])
{
case 'e': extensionFields = 1; break;
case 'i': options |= TAG_IGNORECASE; break;
case 'p': options |= TAG_PARTIALMATCH; break;
case 'l': listTags (); actionSupplied = 1; break;
case 't':
if (arg [j+1] != '\0')
{
TagFileName = arg + j + 1;
j += strlen (TagFileName);
}
else if (i + 1 < argc)
TagFileName = argv [++i];
else
{
fprintf (stderr, Usage, ProgramName);
exit (1);
}
break;
case 's':
SortOverride = 1;
++j;
if (arg [j] == '\0')
SortMethod = TAG_SORTED;
else if (strchr ("012", arg[j]) != NULL)
SortMethod = (sortType) (arg[j] - '0');
else
{
fprintf (stderr, Usage, ProgramName);
exit (1);
}
break;
default:
fprintf (stderr, "%s: unknown option: %c\n",
ProgramName, arg[j]);
exit (1);
break;
}
}
}
}
if (! actionSupplied)
{
fprintf (stderr,
"%s: no action specified: specify tag name(s) or -l option\n",
ProgramName);
exit (1);
}
return 0;
}
#endif
/* vi:set tabstop=4 shiftwidth=4: */
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