pgc.l

postgresql8.3.4源码,开源数据库

<C,xskip>{exec_sql}{else}{space}*";" {	/* only exec sql endif pops the stack, so take care of duplicated 'else' */
					if (stacked_if_value[preproc_tos].else_branch)
						mmerror(PARSE_ERROR, ET_FATAL, "Duplicated 'EXEC SQL ELSE;'");
					else
					{
						stacked_if_value[preproc_tos].else_branch = TRUE;
						stacked_if_value[preproc_tos].condition =
							(stacked_if_value[preproc_tos-1].condition &&
							 !stacked_if_value[preproc_tos].condition);

						if (stacked_if_value[preproc_tos].condition)
							BEGIN(C);
						else
							BEGIN(xskip);
					}
				}
<C,xskip>{informix_special}{else}{space}*	{
					/* are we simulating Informix? */
					if (INFORMIX_MODE)
					{
						if (stacked_if_value[preproc_tos].else_branch)
							mmerror(PARSE_ERROR, ET_FATAL, "Duplicated 'EXEC SQL ELSE;'");
						else
						{
							stacked_if_value[preproc_tos].else_branch = TRUE;
							stacked_if_value[preproc_tos].condition =
							(stacked_if_value[preproc_tos-1].condition &&
							 !stacked_if_value[preproc_tos].condition);

							if (stacked_if_value[preproc_tos].condition)
								BEGIN(C);
							else
								BEGIN(xskip);
						}
					}
					else
					{
						yyless(1);
						return (S_ANYTHING);
					}
				}
<C,xskip>{exec_sql}{endif}{space}*";" {
					if (preproc_tos == 0)
						mmerror(PARSE_ERROR, ET_FATAL, "Unmatched 'EXEC SQL ENDIF;'");
					else
						preproc_tos--;

					if (stacked_if_value[preproc_tos].condition)
					   BEGIN(C);
					else
					   BEGIN(xskip);
				}
<C,xskip>{informix_special}{endif}{space}*";"	{
					/* are we simulating Informix? */
					if (INFORMIX_MODE)
					{
						if (preproc_tos == 0)
							mmerror(PARSE_ERROR, ET_FATAL, "Unmatched 'EXEC SQL ENDIF;'");
						else
							preproc_tos--;

						if (stacked_if_value[preproc_tos].condition)
							BEGIN(C);
						else
							BEGIN(xskip);
					}
					else
					{
						yyless(1);
						return (S_ANYTHING);
					}
				}

<xskip>{other}		{ /* ignore */ }

<xcond>{identifier}{space}*";" {
					if (preproc_tos >= MAX_NESTED_IF-1)
						mmerror(PARSE_ERROR, ET_FATAL, "Too many nested 'EXEC SQL IFDEF' conditions");
					else 
					{
						struct _defines *defptr;
						unsigned int i;

						/*
						 *	Skip the ";" and trailing whitespace. Note that yytext
						 *	contains at least one non-space character plus the ";"
						 */
						for (i = strlen(yytext)-2;
							 i > 0 && ecpg_isspace(yytext[i]);
							 i-- )
							;
						yytext[i+1] = '\0';

						for (defptr = defines;
							 defptr != NULL && strcmp(yytext, defptr->old) != 0;
							 defptr = defptr->next);

						preproc_tos++;
						stacked_if_value[preproc_tos].else_branch = FALSE;
						stacked_if_value[preproc_tos].condition =
						(defptr ? ifcond : !ifcond) && stacked_if_value[preproc_tos-1].condition;
					}

					if (stacked_if_value[preproc_tos].condition)
						BEGIN(C);
					else
						BEGIN(xskip);
				}

<xcond>{other}|\n	{
				mmerror(PARSE_ERROR, ET_FATAL, "Missing identifier in 'EXEC SQL IFDEF' command");
				yyterminate();
			}
<def_ident>{identifier} {
				old = mm_strdup(yytext);
				BEGIN(def);
				startlit();
			}
<def_ident>{other}|\n	{
				mmerror(PARSE_ERROR, ET_FATAL, "Missing identifier in 'EXEC SQL DEFINE' command");
				yyterminate();
			}	
<def>{space}*";"	{
						struct _defines *ptr, *this;

						for (ptr = defines; ptr != NULL; ptr = ptr->next)
						{
							 if (strcmp(old, ptr->old) == 0)
							 {
								free(ptr->new);
								ptr->new = mm_strdup(literalbuf);
							 }
						}
						if (ptr == NULL)
						{
							this = (struct _defines *) mm_alloc(sizeof(struct _defines));

							/* initial definition */
							this->old = old;
							this->new = mm_strdup(literalbuf);
							this->next = defines;
							this->used = NULL;
							defines = this;
						}

						BEGIN(C);
					}
<def>[^;]			{ addlit(yytext, yyleng); }
<incl>\<[^\>]+\>{space}*";"?		{	parse_include(); }
<incl>{dquote}{xdinside}{dquote}{space}*";"?	{	parse_include(); }
<incl>[^;\<\>\"]+";"		{ parse_include(); }
<incl>{other}|\n		{
					mmerror(PARSE_ERROR, ET_FATAL, "Incorrect 'EXEC SQL INCLUDE' command");
					yyterminate();
				}

<<EOF>>				{
			  		if (yy_buffer == NULL)
					{
				  		if ( preproc_tos > 0 ) 
						{
					  		preproc_tos = 0;
							mmerror(PARSE_ERROR, ET_FATAL, "Missing 'EXEC SQL ENDIF;'");
				  		}
						yyterminate();
					}
			  		else
			  		{
						struct _yy_buffer *yb = yy_buffer;
						int i;
						struct _defines *ptr;

						for (ptr = defines; ptr; ptr = ptr->next)
							if (ptr->used == yy_buffer)
							{
								ptr->used = NULL;
								break;
							}
								
						if (yyin != NULL)
							fclose(yyin);

						yy_delete_buffer( YY_CURRENT_BUFFER );
						yy_switch_to_buffer(yy_buffer->buffer);

						yylineno = yy_buffer->lineno;

						/* We have to output the filename only if we change files here */
						i = strcmp(input_filename, yy_buffer->filename);

						free(input_filename);
						input_filename = yy_buffer->filename;

						yy_buffer = yy_buffer->next;
						free(yb);

						if (i != 0)
							output_line_number();
						
			  		}
				}
<INITIAL>{other}|\n     	{ mmerror(PARSE_ERROR, ET_FATAL, "Internal error: unreachable state, please inform [e-mail]"); }
%%
void
lex_init(void)
{
	braces_open = 0;

	preproc_tos = 0;
	yylineno = 1;
	ifcond = TRUE;
	stacked_if_value[preproc_tos].condition = ifcond;
	stacked_if_value[preproc_tos].else_branch = FALSE;

	/* initialize literal buffer to a reasonable but expansible size */
	if (literalbuf == NULL)
	{
		literalalloc = 1024;
		literalbuf = (char *) malloc(literalalloc);
	}
	startlit();

	BEGIN(C);
}

static void
addlit(char *ytext, int yleng)
{
	/* enlarge buffer if needed */
	if ((literallen+yleng) >= literalalloc)
	{
		do 
			literalalloc *= 2;
		while ((literallen+yleng) >= literalalloc);
		literalbuf = (char *) realloc(literalbuf, literalalloc);
	}
	/* append new data, add trailing null */
	memcpy(literalbuf+literallen, ytext, yleng);
	literallen += yleng;
	literalbuf[literallen] = '\0';
}

static void
addlitchar(unsigned char ychar)
{
	/* enlarge buffer if needed */
        if ((literallen+1) >= literalalloc)
        {
                literalalloc *= 2;
                literalbuf = (char *) realloc(literalbuf, literalalloc);
        }
	/* append new data, add trailing null */
	literalbuf[literallen] = ychar;
	literallen += 1;
	literalbuf[literallen] = '\0';
}

static void
parse_include(void)
{
	/* got the include file name */
	struct _yy_buffer *yb;
  	struct _include_path *ip;
  	char inc_file[MAXPGPATH];
  	unsigned int i;

  	yb = mm_alloc(sizeof(struct _yy_buffer));

  	yb->buffer =	YY_CURRENT_BUFFER;
  	yb->lineno = yylineno;
  	yb->filename = input_filename;
  	yb->next = yy_buffer;

  	yy_buffer = yb;

  	/*
	 * skip the ";" if there is one and trailing whitespace. Note that
	 * yytext contains at least one non-space character plus the ";" 
	 */
  	for (i = strlen(yytext)-2;
		 i > 0 && ecpg_isspace(yytext[i]);
		 i--)
		;

	if (yytext[i] == ';')
		i--;

	yytext[i+1] = '\0';
	
	yyin = NULL;

	/* If file name is enclosed in '"' remove these and look only in '.' */
	/* Informix does look into all include paths though, except filename starts with '/' */
	if (yytext[0] == '"' && yytext[i] == '"' &&
	    ((compat != ECPG_COMPAT_INFORMIX && compat != ECPG_COMPAT_INFORMIX_SE) || yytext[1] == '/'))
	{
		yytext[i] = '\0';
		memmove(yytext, yytext+1, strlen(yytext));
	
		strncpy(inc_file, yytext, sizeof(inc_file));
		yyin = fopen(inc_file, "r");
		if (!yyin)
		{
			if (strcmp(inc_file + strlen(inc_file) - 2, ".h"))
			{
				strcat(inc_file, ".h");
				yyin = fopen(inc_file, "r");
			}
		}
		
	}
	else
	{
		if ((yytext[0] == '"' && yytext[i] == '"') || (yytext[0] == '<' && yytext[i] == '>'))
		{
			yytext[i] = '\0';
			memmove(yytext, yytext+1, strlen(yytext));
		}
		
	  	for (ip = include_paths; yyin == NULL && ip != NULL; ip = ip->next)
	  	{
			if (strlen(ip->path) + strlen(yytext) + 3 > MAXPGPATH)
			{
				fprintf(stderr, "Error: Path %s/%s is too long in line %d, skipping.\n", ip->path, yytext, yylineno);
				continue;
			}
			snprintf (inc_file, sizeof(inc_file), "%s/%s", ip->path, yytext);
			yyin = fopen(inc_file, "r");
			if (!yyin)
			{
				if (strcmp(inc_file + strlen(inc_file) - 2, ".h"))
				{
					strcat(inc_file, ".h");
					yyin = fopen( inc_file, "r" );
				}
			}
		}
	}
	if (!yyin)
		mmerror(NO_INCLUDE_FILE, ET_FATAL, "Cannot open include file %s in line %d\n", yytext, yylineno);

	input_filename = mm_strdup(inc_file);
	yy_switch_to_buffer(yy_create_buffer(yyin,YY_BUF_SIZE ));
	yylineno = 1;
	output_line_number();

  	BEGIN(C);
}

/*
 * ecpg_isspace() --- return TRUE if flex scanner considers char whitespace
 */
static bool
ecpg_isspace(char ch)
{
	if (ch == ' ' ||
		ch == '\t' ||
		ch == '\n' ||
		ch == '\r' ||
		ch == '\f')
		return true;
	return false;
}

static bool isdefine(void)
{
	struct _defines *ptr;

	/* is it a define? */
	for (ptr = defines; ptr; ptr = ptr->next)
	{
		if (strcmp(yytext, ptr->old) == 0 && ptr->used == NULL)
		{
			struct _yy_buffer *yb;

			yb = mm_alloc(sizeof(struct _yy_buffer));

			yb->buffer =  YY_CURRENT_BUFFER;
			yb->lineno = yylineno;
			yb->filename = mm_strdup(input_filename);
			yb->next = yy_buffer;

			ptr->used = yy_buffer = yb;

			yy_scan_string(ptr->new);
			return true;
		}
	}

	return false;
}

static bool isinformixdefine(void)
{
	const char *new = NULL;

	if (strcmp(yytext, "dec_t") == 0)
		new = "decimal";
	else if (strcmp(yytext, "intrvl_t") == 0)
	        new = "interval";
	else if (strcmp(yytext, "dtime_t") == 0)
                new = "timestamp";

	if (new)
	{
		struct _yy_buffer *yb;

		yb = mm_alloc(sizeof(struct _yy_buffer));

		yb->buffer =  YY_CURRENT_BUFFER;
		yb->lineno = yylineno;
		yb->filename = mm_strdup(input_filename);
		yb->next = yy_buffer;
		yy_buffer = yb;

		yy_scan_string(new);
		return true;
	}

	return false;
}

/*
 * Called before any actual parsing is done
 */
void
scanner_init(const char *str)
{
	Size	slen = strlen(str);

	/*
	 * Might be left over after ereport()
	 */
	if (YY_CURRENT_BUFFER)
		yy_delete_buffer(YY_CURRENT_BUFFER);

	/*
	 * Make a scan buffer with special termination needed by flex.
	 */
	scanbuf = mm_alloc(slen + 2);
	memcpy(scanbuf, str, slen);
	scanbuf[slen] = scanbuf[slen + 1] = YY_END_OF_BUFFER_CHAR;
	scanbufhandle = yy_scan_buffer(scanbuf, slen + 2);

	/* initialize literal buffer to a reasonable but expansible size */
	literalalloc = 128;
	literalbuf = (char *) mm_alloc(literalalloc);
	startlit();

	BEGIN(INITIAL);
}


/*
 * Called after parsing is done to clean up after scanner_init()
 */
void
scanner_finish(void)
{
	yy_delete_buffer(scanbufhandle);
	free(scanbuf);
}