commit 33f4fef4101f4c834516ad3be9869d90182559c4
parent e77534c08f6470c01ee8be2b609422ef0834463b
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 11 Jun 1997 15:55:42 -0300
BUG: did not handle properly pragmas $endinput/$debug inside a $if.
Diffstat:
M | lex.c | | | 80 | +++++++++++++++++++++++++++++++++++++++++++------------------------------------ |
1 file changed, 44 insertions(+), 36 deletions(-)
diff --git a/lex.c b/lex.c
@@ -1,4 +1,4 @@
-char *rcs_lex = "$Id: lex.c,v 3.2 1997/04/14 15:30:29 roberto Exp roberto $";
+char *rcs_lex = "$Id: lex.c,v 3.4 1997/06/11 14:20:51 roberto Exp $";
#include <ctype.h>
@@ -23,17 +23,17 @@ char *rcs_lex = "$Id: lex.c,v 3.2 1997/04/14 15:30:29 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 */
+#define MAX_IFS 5
+
+/* "ifstate" keeps the state of each nested $if the lexical is dealing with. */
+
+static struct {
+ int elsepart; /* true if its in the $else part */
+ int condition; /* true if $if condition is true */
+ int skip; /* true if part must be skiped */
+} ifstate[MAX_IFS];
+
static int iflevel; /* level of nested $if's */
@@ -42,6 +42,8 @@ void lua_setinput (Input fn)
current = '\n';
lua_linenumber = 0;
iflevel = 0;
+ ifstate[0].skip = 0;
+ ifstate[0].elsepart = 1; /* to avoid a free $else */
input = fn;
}
@@ -117,10 +119,9 @@ static void skipspace (void)
static int checkcond (char *buff)
{
- if (strcmp(buff, "nil") == 0)
- return 0;
- else if (strcmp(buff, "1") == 0)
- return 1;
+ static char *opts[] = {"nil", "1"};
+ int i = luaI_findstring(buff, opts);
+ if (i >= 0) return i;
else if (isalpha((unsigned char)buff[0]) || buff[0] == '_')
return luaI_globaldefined(buff);
else {
@@ -149,11 +150,9 @@ static void readname (char *buff)
static void inclinenumber (void);
-static void ifskip (int thisiflevel)
+static void ifskip (void)
{
- if (thisiflevel < 0) return;
- while (iflevel > thisiflevel &&
- (ifstate[thisiflevel] == 0 || ifstate[thisiflevel] == 3)) {
+ while (ifstate[iflevel].skip) {
if (current == '\n')
inclinenumber();
else if (current == 0)
@@ -166,51 +165,60 @@ static void ifskip (int thisiflevel)
static void inclinenumber (void)
{
static char *pragmas [] =
- {"debug", "nodebug", "end", "ifnot", "if", "else", "endinput", NULL};
+ {"debug", "nodebug", "endinput", "end", "ifnot", "if", "else", NULL};
next(); /* skip '\n' */
++lua_linenumber;
if (current == '$') { /* is a pragma? */
char buff[PRAGMASIZE+1];
int ifnot = 0;
+ int skip = ifstate[iflevel].skip;
next(); /* skip $ */
readname(buff);
switch (luaI_findstring(buff, pragmas)) {
case 0: /* debug */
- lua_debug = 1;
+ if (!skip) lua_debug = 1;
break;
case 1: /* nodebug */
- lua_debug = 0;
+ if (!skip) lua_debug = 0;
break;
- case 2: /* end */
- if (--iflevel < 0)
+ case 2: /* endinput */
+ if (!skip) {
+ current = 0;
+ iflevel = 0; /* to allow $endinput inside a $if */
+ }
+ break;
+ case 3: /* end */
+ if (iflevel-- == 0)
luaI_auxsyntaxerror("unmatched $endif");
break;
- case 3: /* ifnot */
+ case 4: /* ifnot */
ifnot = 1;
/* go through */
- case 4: /* if */
- if (iflevel == MAX_IFS)
+ case 5: /* if */
+ if (iflevel == MAX_IFS-1)
luaI_auxsyntaxerror("too many nested `$ifs'");
readname(buff);
- ifstate[iflevel++] = checkcond(buff) ? !ifnot : ifnot;
+ iflevel++;
+ ifstate[iflevel].elsepart = 0;
+ ifstate[iflevel].condition = checkcond(buff) ? !ifnot : ifnot;
+ ifstate[iflevel].skip = skip || !ifstate[iflevel].condition;
break;
- case 5: /* else */
- if (iflevel <= 0 || (ifstate[iflevel-1] & 2))
+ case 6: /* else */
+ if (ifstate[iflevel].elsepart)
luaI_auxsyntaxerror("unmatched $else");
- ifstate[iflevel-1] = ifstate[iflevel-1] | 2;
- break;
- case 6: /* endinput */
- current = 0;
+ ifstate[iflevel].elsepart = 1;
+ ifstate[iflevel].skip =
+ ifstate[iflevel-1].skip || ifstate[iflevel].condition;
break;
default:
luaI_auxsynterrbf("invalid pragma", buff);
}
skipspace();
- if (current == '\n') /* pragma must end with a '\n' */
+ if (current == '\n') /* pragma must end with a '\n' ... */
inclinenumber();
else if (current != 0) /* or eof */
luaI_auxsyntaxerror("invalid pragma format");
- ifskip(iflevel-1);
+ ifskip();
}
}