commit a8cd072c76da0a9f11c86d3e44766ecf97a3f402
parent 83e9897cf0c7a8172be162b0413f30b892932dc6
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Sat, 12 Apr 1997 12:01:29 -0300
nested "$if's", "$else", and "$if" constants (nil & 1).
Diffstat:
| M | lex.c | | | 142 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------- |
1 file changed, 103 insertions(+), 39 deletions(-)
diff --git a/lex.c b/lex.c
@@ -1,4 +1,4 @@
-char *rcs_lex = "$Id: lex.c,v 2.45 1997/04/01 21:23:20 roberto Exp roberto $";
+char *rcs_lex = "$Id: lex.c,v 2.46 1997/04/07 14:48:53 roberto Exp roberto $";
#include <ctype.h>
@@ -22,6 +22,18 @@ char *rcs_lex = "$Id: lex.c,v 2.45 1997/04/01 21:23:20 roberto Exp roberto $";
static int current; /* look ahead character */
static Input input; /* input function */
+
+#define MAX_IFS 10
+
+/* "ifstate" keeps the state of each nested $if the lexical is
+** dealing with. The first bit indicates whether the $if condition
+** is false or true. The second bit indicates whether the lexical is
+** inside the "then" part (0) or the "else" part (2)
+*/
+static int ifstate[MAX_IFS]; /* 0 => then part - condition false */
+ /* 1 => then part - condition true */
+ /* 2 => else part - condition false */
+ /* 3 => else part - condition true */
static int iflevel; /* level of nested $if's */
@@ -33,11 +45,15 @@ void lua_setinput (Input fn)
input = fn;
}
-static void luaI_auxsyntaxerror (char *s, char *token)
+
+static void luaI_auxsyntaxerror (char *s)
+{
+ luaL_verror("%s;\n> at line %d in file %s",
+ s, lua_linenumber, lua_parsedfile);
+}
+
+static void luaI_auxsynterrbf (char *s, char *token)
{
- if (token == NULL)
- luaL_verror("%s;\n> at line %d in file %s",
- s, lua_linenumber, lua_parsedfile);
if (token[0] == 0)
token = "<eof>";
luaL_verror("%s;\n> last token read: \"%s\" at line %d in file %s",
@@ -46,7 +62,7 @@ static void luaI_auxsyntaxerror (char *s, char *token)
void luaI_syntaxerror (char *s)
{
- luaI_auxsyntaxerror(s, luaI_buffer(1));
+ luaI_auxsynterrbf(s, luaI_buffer(1));
}
@@ -87,27 +103,74 @@ void luaI_addReserved (void)
}
+/*
+** Pragma handling
+*/
+
+#define PRAGMASIZE 20
+
+static void skipspace (void)
+{
+ while (current == ' ' || current == '\t') next();
+}
+
+
+static int checkcond (char *buff)
+{
+ if (strcmp(buff, "nil") == 0)
+ return 0;
+ else if (strcmp(buff, "1") == 0)
+ return 1;
+ else if (isalpha((unsigned char)buff[0]))
+ return luaI_globaldefined(buff);
+ else {
+ luaI_auxsynterrbf("invalid $if condition", buff);
+ return 0; /* to avoid warnings */
+ }
+}
+
+
static void readname (char *buff)
{
int i = 0;
- while (current == ' ') next();
+ skipspace();
while (isalnum((unsigned char)current)) {
- if (i >= MINBUFF) luaI_syntaxerror("pragma too long");
+ if (i >= PRAGMASIZE) {
+ buff[PRAGMASIZE] = 0;
+ luaI_auxsynterrbf("pragma too long", buff);
+ }
buff[i++] = current;
next();
}
buff[i] = 0;
- if (!isalpha(buff[0]) || (current != 0 && !isspace(current)))
- luaI_auxsyntaxerror("invalid pragma format", NULL);
}
-static int inclinenumber (void)
+
+static void inclinenumber (void);
+
+
+static void ifskip (int thisiflevel)
+{
+ while (iflevel > thisiflevel &&
+ (ifstate[thisiflevel] == 0 || ifstate[thisiflevel] == 3)) {
+ if (current == '\n')
+ inclinenumber();
+ else if (current == 0)
+ luaI_auxsyntaxerror("input ends inside a $if");
+ else next();
+ }
+}
+
+
+static void inclinenumber (void)
{
- static char *pragmas [] = {"debug", "nodebug", "endif", "ifnil", "if", NULL};
- int ifnil = 0;
+ static char *pragmas [] =
+ {"debug", "nodebug", "end", "ifnot", "if", "else", NULL};
+ next(); /* skip '\n' */
++lua_linenumber;
if (current == '$') { /* is a pragma? */
- char buff[MINBUFF+1];
+ char buff[PRAGMASIZE+1];
+ int ifnot = 0;
next(); /* skip $ */
readname(buff);
switch (luaI_findstring(buff, pragmas)) {
@@ -117,34 +180,35 @@ static int inclinenumber (void)
case 1: /* nodebug */
lua_debug = 0;
break;
- case 2: /* endif */
+ case 2: /* end */
if (--iflevel < 0)
- luaI_auxsyntaxerror("too many $endif's", NULL);
+ luaI_auxsyntaxerror("unmatched $endif");
break;
- case 3: /* ifnil */
- ifnil = 1;
+ case 3: /* ifnot */
+ ifnot = 1;
/* go through */
- case 4: { /* if */
- int thisiflevel = iflevel++;
+ case 4: /* if */
+ if (iflevel == MAX_IFS)
+ luaI_auxsyntaxerror("too many nested `$ifs'");
readname(buff);
- if ((ifnil && luaI_globaldefined(buff)) ||
- (!ifnil && !luaI_globaldefined(buff))) { /* skip the $if? */
- do {
- if (current == '\n') {
- next();
- inclinenumber();
- }
- else if (current == 0)
- luaI_auxsyntaxerror("input ends inside a $if", NULL);
- else next();
- } while (iflevel > thisiflevel);
- }
+ ifstate[iflevel++] = checkcond(buff) ? !ifnot : ifnot;
break;
- }
- default: luaI_auxsyntaxerror("invalid pragma", buff);
+ case 5: /* else */
+ if (iflevel <= 0 || (ifstate[iflevel-1] & 2))
+ luaI_auxsyntaxerror("unmatched $else");
+ ifstate[iflevel-1] = ifstate[iflevel-1] | 2;
+ break;
+ default:
+ luaI_auxsynterrbf("invalid pragma", buff);
}
+ skipspace();
+ if (current == '\n') /* pragma must end with a '\n' */
+ inclinenumber();
+ else if (current != 0) /* or eof */
+ luaI_auxsyntaxerror("invalid pragma format");
+ if (iflevel > 0)
+ ifskip(iflevel-1);
}
- return lua_linenumber;
}
static int read_long_string (char *yytext, int buffsize)
@@ -178,7 +242,7 @@ static int read_long_string (char *yytext, int buffsize)
}
continue;
case '\n':
- save_and_next();
+ save('\n');
inclinenumber();
continue;
default:
@@ -209,8 +273,8 @@ int luaY_lex (void)
switch (current)
{
case '\n':
- next();
- linelasttoken = inclinenumber();
+ inclinenumber();
+ linelasttoken = lua_linenumber;
continue;
case ' ': case '\t': case '\r': /* CR: to avoid problems with DOS */
@@ -274,7 +338,7 @@ int luaY_lex (void)
case 'n': save('\n'); next(); break;
case 't': save('\t'); next(); break;
case 'r': save('\r'); next(); break;
- case '\n': save_and_next(); inclinenumber(); break;
+ case '\n': save('\n'); inclinenumber(); break;
default : save_and_next(); break;
}
break;
