/*
*   $Id: parse.c,v 1.3 2002/02/16 19:53:16 darren Exp $
*
*   Copyright (c) 1996-2001, Darren Hiebert
*
*   This source code is released for free distribution under the terms of the
*   GNU General Public License.
*
*   This module contains functions for managing source languages and
*   dispatching files to the appropriate language parser.
*/

/*
*   INCLUDE FILES
*/
#include "general.h"	/* must always come first */

#include <string.h>
#ifdef HAVE_FNMATCH_H
#include <fnmatch.h>
#endif

#include "debug.h"
#include "entry.h"
#include "main.h"
#define OPTION_WRITE
#include "options.h"
#include "parsers.h" 
#include "read.h"
#include "routines.h"
#include "vstring.h"

/*
*   DATA DEFINITIONS
*/
static parserDefinitionFunc* BuiltInParsers[] = { PARSER_LIST };
static parserDefinition** LanguageTable = NULL;
static unsigned int LanguageCount = 0;

/*
*   FUNCTION DEFINITIONS
*/

extern void makeSimpleTag (const vString* const name,
			   kindOption* const kinds, const int kind)
{
    if (kinds [kind].enabled  &&  name != NULL  &&  vStringLength (name) > 0)
    {
        tagEntryInfo e;
        initTagEntry (&e, vStringValue (name));

        e.kindName = kinds [kind].name;
        e.kind     = kinds [kind].letter;

        makeTagEntry (&e);
    }
}

/*
*   parserDescription mapping management
*/

extern parserDefinition* parserNew (const char* name)
{
    parserDefinition* result = xCalloc (1, parserDefinition);
    result->name = eStrdup (name);
    return result;
}

extern const char *getLanguageName (const langType language)
{
    const char* result;
    if (language == LANG_IGNORE)
	result = "unknown";
    else
    {
	Assert (0 <= language  &&  language < (int) LanguageCount);
	result = LanguageTable [language]->name;
    }
    return result;
}

extern langType getNamedLanguage (const char *const name)
{
    langType result = LANG_IGNORE;
    unsigned int i;
    Assert (name != NULL);
    for (i = 0  ;  i < LanguageCount  &&  result == LANG_IGNORE  ;  ++i)
    {
	if (LanguageTable [i]->name != NULL)
	    if (strcasecmp (name, LanguageTable [i]->name) == 0)
		result = i;
    }
    return result;
}

static langType getExtensionLanguage (const char *const extension)
{
    langType result = LANG_IGNORE;
    unsigned int i;
    for (i = 0  ;  i < LanguageCount  &&  result == LANG_IGNORE  ;  ++i)
    {
	stringList* const exts = LanguageTable [i]->currentExtensions;
	if (exts != NULL  &&  stringListExtensionMatched (exts, extension))
	    result = i;
    }
    return result;
}

static langType getPatternLanguage (const char *const fileName)
{
    langType result = LANG_IGNORE;
    const char* base = baseFilename (fileName);
    unsigned int i;
    for (i = 0  ;  i < LanguageCount  &&  result == LANG_IGNORE  ;  ++i)
    {
	stringList* const ptrns = LanguageTable [i]->currentPatterns;
	if (ptrns != NULL  &&  stringListFileMatched (ptrns, base))
	    result = i;
    }
    return result;
}

#ifdef SYS_INTERPRETER

/*  The name of the language interpreter, either directly or as the argument
 *  to "env".
 */
static vString* determineInterpreter (const char* const cmd)
{
    vString* const interpreter = vStringNew ();
    const char* p = cmd;
    do
    {
	vStringClear (interpreter);
	for ( ;  isspace (*p)  ;  ++p)
	    ; /* no-op */
	for ( ;  *p != '\0'  &&  ! isspace (*p)  ;  ++p)
	    vStringPut (interpreter, (int) *p);
	vStringTerminate (interpreter);
    } while (strcmp (vStringValue (interpreter), "env") == 0);
    return interpreter;
}

static langType getInterpreterLanguage (const char *const fileName)
{
    langType result = LANG_IGNORE;
    FILE* const fp = fopen (fileName, "r");
    if (fp != NULL)
    {
	vString* const vLine = vStringNew ();
	const char* const line = readLine (vLine, fp);
	if (line != NULL  &&  line [0] == '#'  &&  line [1] == '!')
	{
	    const char* const lastSlash = strrchr (line, '/');
	    const char *const cmd = lastSlash != NULL ? lastSlash+1 : line+2;
	    vString* const interpreter = determineInterpreter (cmd);
	    result = getExtensionLanguage (vStringValue (interpreter));
	    vStringDelete (interpreter);
	}
	vStringDelete (vLine);
	fclose (fp);
    }
    return result;
}

#endif

extern langType getFileLanguage (const char *const fileName)
{
    langType language = Option.language;
    if (language == LANG_AUTO)
    {
	language = getExtensionLanguage (fileExtension (fileName));
	if (language == LANG_IGNORE)
	    language = getPatternLanguage (fileName);
#ifdef SYS_INTERPRETER
	if (language == LANG_IGNORE  &&  isExecutable (fileName))
	    language = getInterpreterLanguage (fileName);
#endif
    }
    return language;
}

extern void printLanguageMap (const langType language)
{
    boolean first = TRUE;
    unsigned int i;
    stringList* map = LanguageTable [language]->currentPatterns;
    Assert (0 <= language  &&  language < (int) LanguageCount);
    for (i = 0  ;  map != NULL  &&  i < stringListCount (map)  ;  ++i)
    {
	printf ("%s(%s)", (first ? "" : " "),
		vStringValue (stringListItem (map, i)));
	first = FALSE;
    }
    map = LanguageTable [language]->currentExtensions;
    for (i = 0  ;  map != NULL  &&  i < stringListCount (map)  ;  ++i)
    {
	printf ("%s.%s", (first ? "" : " "),
		vStringValue (stringListItem (map, i)));
	first = FALSE;
    }
}

extern void installLanguageMapDefault (const langType language)
{
    Assert (language >= 0);
    if (LanguageTable [language]->currentPatterns != NULL)
	stringListDelete (LanguageTable [language]->currentPatterns);
    if (LanguageTable [language]->currentExtensions != NULL)
	stringListDelete (LanguageTable [language]->currentExtensions);

    if (LanguageTable [language]->patterns == NULL)
	LanguageTable [language]->currentPatterns = stringListNew ();
    else
    {
	LanguageTable [language]->currentPatterns =
	    stringListNewFromArgv (LanguageTable [language]->patterns);
    }
    if (LanguageTable [language]->extensions == NULL)
	LanguageTable [language]->currentExtensions = stringListNew ();
    else
    {
	LanguageTable [language]->currentExtensions =
	    stringListNewFromArgv (LanguageTable [language]->extensions);
    }
    if (Option.verbose)
	printLanguageMap (language);
    verbose ("\n");
}

extern void installLanguageMapDefaults (void)
{
    unsigned int i;
    for (i = 0  ;  i < LanguageCount  ;  ++i)
    {
	verbose ("    %s: ", getLanguageName (i));
	installLanguageMapDefault (i);
    }
}

extern void clearLanguageMap (const langType language)
{
    Assert (0 <= language  &&  language < (int) LanguageCount);
    stringListClear (LanguageTable [language]->currentPatterns);
    stringListClear (LanguageTable [language]->currentExtensions);
}

extern void addLanguagePatternMap (const langType language, const char* ptrn)
{
    vString* const str = vStringNewInit (ptrn);
    Assert (0 <= language  &&  language < (int) LanguageCount);
    if (LanguageTable [language]->currentPatterns == NULL)
	LanguageTable [language]->currentPatterns = stringListNew ();
    stringListAdd (LanguageTable [language]->currentPatterns, str);
}

extern void addLanguageExtensionMap (const langType language,
				     const char* extension)
{
    vString* const str = vStringNewInit (extension);
    Assert (0 <= language  &&  language < (int) LanguageCount);
    stringListAdd (LanguageTable [language]->currentExtensions, str);
}

extern void enableLanguages (const boolean state)
{
    unsigned int i;
    for (i = 0  ;  i < LanguageCount  ;  ++i)
	LanguageTable [i]->enabled = state;
}

extern void enableLanguage (const langType language, const boolean state)
{
    Assert (0 <= language  &&  language < (int) LanguageCount);
    LanguageTable [language]->enabled = state;
}

static void initializeParsers (void)
{
    unsigned int i;
    for (i = 0  ;  i < LanguageCount  ;  ++i)
	if (LanguageTable [i]->initialize != NULL)
	    (LanguageTable [i]->initialize) ((langType) i);
}

extern void initializeParsing (void)
{
    unsigned int builtInCount;
    unsigned int i;

    builtInCount = sizeof (BuiltInParsers) / sizeof (BuiltInParsers [0]);
    LanguageTable = xMalloc (builtInCount, parserDefinition*);

    verbose ("Installing parsers: ");
    for (i = 0  ;  i < builtInCount  ;  ++i)
    {
	parserDefinition* const def = (*BuiltInParsers [i]) ();
	if (def != NULL)
	{
	    boolean accepted = FALSE;
	    if (def->name == NULL  ||  def->name[0] == '\0')
		error (FATAL, "parser definition must contain name\n");
	    else if (def->regex)
	    {
#ifdef HAVE_REGEX
		def->parser = findRegexTags;
		accepted = TRUE;
#endif
	    }
	    else if ((def->parser == NULL)  ==  (def->parser2 == NULL))
		error (FATAL,
	"%s parser definition must define one and only one parsing routine\n",
		       def->name);
	    else
		accepted = TRUE;
	    if (accepted)
	    {
		verbose ("%s%s", i > 0 ? ", " : "", def->name);
		def->id = LanguageCount++;
		LanguageTable [def->id] = def;
	    }
	}
    }
    verbose ("\n");
    enableLanguages (TRUE);
    initializeParsers ();
}

extern void freeParserResources (void)
{
    unsigned int i;
    for (i = 0  ;  i < LanguageCount  ;  ++i)
    {
	freeList (&LanguageTable [i]->currentPatterns);
	freeList (&LanguageTable [i]->currentExtensions);
	eFree (LanguageTable [i]->name);
	LanguageTable [i]->name = NULL;
	eFree (LanguageTable [i]);
    }
    eFree (LanguageTable);
    LanguageTable = NULL;
    LanguageCount = 0;
}

/*
*   Option parsing
*/

extern void processLanguageDefineOption (const char *const option,
					 const char *const __unused__ parameter)
{
#ifdef HAVE_REGEX
    if (parameter [0] == '\0')
	error (WARNING, "No language specified for \"%s\" option", option);
    else if (getNamedLanguage (parameter) != LANG_IGNORE)
	error (WARNING, "Language \"%s\" already defined", parameter);
    else
    {
	unsigned int i = LanguageCount++;
	parserDefinition* const def = parserNew (parameter);
	def->parser            = findRegexTags;
	def->currentPatterns   = stringListNew ();
	def->currentExtensions = stringListNew ();
	def->regex             = TRUE;
	def->enabled           = TRUE;
	def->id                = i;
	LanguageTable = xRealloc (LanguageTable, i + 1, parserDefinition*);
	LanguageTable [i] = def;
    }
#else
    error (WARNING, "regex support not available; required for --%s option",
	   option);
#endif
}

static kindOption *langKindOption (const langType language, const int flag)
{
    unsigned int i;
    kindOption* result = NULL;
    const parserDefinition* lang;
    Assert (0 <= language  &&  language < (int) LanguageCount);
    lang = LanguageTable [language];
    for (i=0  ;  i < lang->kindCount  &&  result == NULL  ;  ++i)
	if (lang->kinds [i].letter == flag)
	    result = &lang->kinds [i];
    return result;
}

extern void processLegacyKindOption (const char *const parameter)
{
    const langType lang = getNamedLanguage ("c");
    boolean clear = FALSE;
    const char* p = parameter;
    boolean mode = TRUE;
    int c;

    error (WARNING, "-i option is deprecated; use --c-types option instead");
    if (*p == '=')
    {
	clear = TRUE;
	++p;
    }
    if (clear  &&  *p != '+'  &&  *p != '-')
    {
	unsigned int i;
	for (i = 0  ;  i < LanguageTable [lang]->kindCount  ;  ++i)
	    LanguageTable [lang]->kinds [i].enabled = FALSE;
	Option.include.fileNames= FALSE;
	Option.include.fileScope= FALSE;
    }
    while ((c = *p++) != '\0') switch (c)
    {
	case '+': mode = TRUE;  break;
	case '-': mode = FALSE; break;

	case 'F': Option.include.fileNames = mode; break;
	case 'S': Option.include.fileScope = mode; break;

	default:
	{
	    kindOption* const opt = langKindOption (lang, c);
	    if (opt != NULL)
		opt->enabled = mode;
	    else
		error (WARNING, "Unsupported parameter '%c' for -i option", c);
	} break;
    }
}

static void disableLanguageKinds (const langType language)
{
    if (LanguageTable [language]->regex)
	disableRegexKinds (language);
    else
    {
	unsigned int i;
	for (i = 0  ;  i < LanguageTable [language]->kindCount  ;  ++i)
	    LanguageTable [language]->kinds [i].enabled = FALSE;
    }
}

static boolean enableLanguageKind (const langType language,
				   const int kind, const boolean mode)
{
    boolean result = FALSE;
    if (LanguageTable [language]->regex)
	result = enableRegexKind (language, kind, mode);
    else
    {
	kindOption* const opt = langKindOption (language, kind);
	if (opt != NULL)
	{
	    opt->enabled = mode;
	    result = TRUE;
	}
    }
    return result;
}

static void processLangKindOption (const langType language,
				   const char *const option,
				   const char *const parameter)
{
    const char *p = parameter;
    boolean mode = TRUE;
    int c;

    Assert (0 <= language  &&  language < (int) LanguageCount);
    if (*p != '+'  &&  *p != '-')
	disableLanguageKinds (language);
    while ((c = *p++) != '\0') switch (c)
    {
	case '+': mode = TRUE;  break;
	case '-': mode = FALSE; break;

	default:
	{
	    if (! enableLanguageKind (language, c, mode))
		error (WARNING, "Unsupported parameter '%c' for --%s option",
		    c, option);
	} break;
    }
}

extern boolean processKindOption (const char *const option,
				  const char *const parameter)
{
    boolean handled = FALSE;
    const char* const dash = strchr (option, '-');
    if (dash != NULL  &&
	(strcmp (dash + 1, "types") == 0  ||  strcmp (dash + 1, "kinds") == 0))
    {
	langType language;
	vString* langName = vStringNew ();
	vStringNCopyS (langName, option, dash - option);
	language = getNamedLanguage (vStringValue (langName));
	if (language == LANG_IGNORE)
	    error (WARNING, "Unknown language specified in \"%s\" option", option);
	else
	    processLangKindOption (language, option, parameter);
	vStringDelete (langName);
	handled = TRUE;
    }
    return handled;
}

static void printLangugageKindOption (const kindOption* const kind)
{
    printf ("          %c  %s%s\n", kind->letter,
	kind->description != NULL ? kind->description :
	    (kind->name != NULL ? kind->name : ""),
	kind->enabled ? "" : " [off]");
}

static void printLangugageKindOptions (const langType language)
{
    const parserDefinition* lang;
    Assert (0 <= language  &&  language < (int) LanguageCount);
    lang = LanguageTable [language];
    if (lang->kinds != NULL  ||  lang->regex)
    {
	unsigned int i;
	char* const name = newLowerString (lang->name);
	printf ("  --%s-types=[+|-]kinds\n", name);
	eFree (name);
	if (lang->kinds != NULL)
	    for (i = 0  ;  i < lang->kindCount  ;  ++i)
		printLangugageKindOption (lang->kinds + i);
	printRegexKindOptions (language);
    }
}

extern void printKindOptions (void)
{
    unsigned int i;

    printf (
 "\n  The following options are used to specify which language-specific tag\n\
  types (or kinds) should be included in the tag file. \"Kinds\" is a group of\n\
  one-letter flags designating kinds of tags to either include or exclude from\n\
  the output. Each letter or group of letters may be preceded by either '+' to\n");
    printf (
 "  add it to those already included, or '-' to exclude it from the output. In\n\
  the absence of any preceding '+' or '-' sign, only those kinds listed in\n\
  \"kinds\" will be included in the output. Below each option is a list of the\n\
  flags accepted. All kinds are enabled by default unless otherwise noted.\n\n");

    for (i = 0  ;  i < LanguageCount  ;  ++i)
	printLangugageKindOptions (i);
}

/*
*   File parsing
*/

static void makeFileTag (const char *const fileName)
{
    if (Option.include.fileNames)
    {
	tagEntryInfo tag;
	initTagEntry (&tag, baseFilename (fileName));

	tag.isFileEntry     = TRUE;
	tag.lineNumberEntry = TRUE;
	tag.lineNumber      = 1;
	tag.kindName        = "file";
	tag.kind            = 'F';

	makeTagEntry (&tag);
    }
}

static boolean createTagsForFile (const char *const fileName,
				  const langType language,
				  const unsigned int passCount)
{
    boolean retried = FALSE;

    if (fileOpen (fileName, language))
    {
	if (Option.etags)
	    beginEtagsFile ();

	makeFileTag (fileName);

	if (LanguageTable [language]->parser != NULL)
	    LanguageTable [language]->parser ();
	else if (LanguageTable [language]->parser2 != NULL)
	    retried = LanguageTable [language]->parser2 (passCount);

	if (Option.etags)
	    endEtagsFile (getSourceFileTagPath ());

	fileClose ();
    }

    return retried;
}

static boolean createTagsWithFallback (const char *const fileName,
				       const langType language)
{
    const unsigned long numTags	= TagFile.numTags.added;
    fpos_t tagFilePosition;
    unsigned int passCount = 0;
    boolean tagFileResized = FALSE;

    fgetpos (TagFile.fp, &tagFilePosition);
    while (createTagsForFile (fileName, language, ++passCount))
    {
	/*  Restore prior state of tag file.
	 */
	fsetpos (TagFile.fp, &tagFilePosition);
	TagFile.numTags.added = numTags;
	tagFileResized = TRUE;
    }
    return tagFileResized;
}

extern boolean parseFile (const char *const fileName)
{
    boolean tagFileResized = FALSE;
    langType language = Option.language;
    if (Option.language == LANG_AUTO)
	language = getFileLanguage (fileName);
    Assert (language != LANG_AUTO);
    if (language == LANG_IGNORE)
	verbose ("ignoring %s (unknown language)\n", fileName);
    else if (! LanguageTable [language]->enabled)
	verbose ("ignoring %s (language disabled)\n", fileName);
    else
    {
	if (Option.filter)
	    openTagFile ();

	tagFileResized = createTagsWithFallback (fileName, language);

	if (Option.filter)
	    closeTagFile (tagFileResized);
	addTotals (1, 0L, 0L);

	return tagFileResized;
    }
    return tagFileResized;
}

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