milestone: added grammar for arithmetic expressions

6 files changed, 146 insertions, 18 deletions

diff --git a/grammar/makefile b/grammar/makefile
index 29aab217..eb6c9522 100644
--- a/grammar/makefile
+++ b/grammar/makefile
@@ -1,5 +1,5 @@
 rscript: lex.yy.c utils.o rscript.tab.h utils.h
-	gcc -o rscript lex.yy.c rscript.tab.c utils.o -lestr
+	gcc -g -o rscript lex.yy.c rscript.tab.c utils.o -lestr
 
 lex.yy.c: rscript.l rscript.tab.h
 	flex rscript.l
@@ -8,4 +8,7 @@ rscript.tab.h: rscript.y
 	bison -d rscript.y
 
 utils.o: utils.c utils.h
-	gcc -c utils.c
+	gcc -g -Wall -c utils.c
+
+clean:
+	rm *.o
diff --git a/grammar/mini.samp b/grammar/mini.samp
index 54efacec..6aae758d 100644
--- a/grammar/mini.samp
+++ b/grammar/mini.samp
@@ -24,7 +24,7 @@ if 1 then { /var/log/log3
 	@@fwd
     	rger
     }
-if 1/*pri("*.*")*/ then {
+if 2*4/5--(10-3)/*pri("*.*")*/ then {
    action(type="omfile" taget="/var/log/log5")
    action(type="omfile" taget="/var/log/log6")
    action(type="omfwd" taget="10.0.0.1" port="514")
diff --git a/grammar/rscript.l b/grammar/rscript.l
index d6dab45b..f7e51e25 100644
--- a/grammar/rscript.l
+++ b/grammar/rscript.l
@@ -45,11 +45,16 @@ static int preCommentState;
  /* keywords */
 "if"				{ BEGIN EXPR; return IF; }
 <EXPR>"then"			{ BEGIN INITIAL; return THEN; }
-<EXPR>"or"			{ printf("OR\n"); }
-<EXPR>"and"			{ printf("AND\n"); }
-<EXPR>"not"			{ printf("NOT\n"); }
-<EXPR>"("			{ printf("LPAREN\n"); }
-<EXPR>")"			{ printf("RPAREN\n"); }
+<EXPR>"or"			{ return OR; }
+<EXPR>"and"			{ return AND; }
+<EXPR>"not"			{ return NOT; }
+<EXPR>"*" |
+<EXPR>"/" |
+<EXPR>"%" |
+<EXPR>"+" |
+<EXPR>"-" |
+<EXPR>"(" |
+<EXPR>")"			{ return yytext[0]; }
 <EXPR>"=="			{ printf("==\n"); }
 <EXPR>"<="			{ printf("<=\n"); }
 <EXPR>">="			{ printf(">=\n"); }
@@ -61,11 +66,12 @@ static int preCommentState;
 <EXPR>"contains_i"		{ printf("CONTAINS_I\n"); }
 <EXPR>"startswith"		{ printf("STARTSWITH\n"); }
 <EXPR>"startswith_i"		{ printf("STARTSWITH_I\n"); }
-<EXPR>-?0[0-7]+			{ printf("NUMBER (oct) %s\n", yytext); }
-<EXPR>-?0x[0-7a-f]		{ printf("NUMBER (hex) %s\n", yytext); }
-<EXPR>-?([1-9][0-9]*|0)		{ printf("NUMBER (dec) %s\n", yytext); return NUMBER; }
-<EXPR>\$[$!]{0,1}[a-z][a-z0-9\-_\.]*	{ printf("VARNAME: '%s'\n", yytext); }
-<EXPR>\'([^'\\]|\\['])*\'	 { printf("EXPR string: -%s-\n", yytext); }
+<EXPR>0[0-7]+			{ printf("NUMBER (oct) %s\n", yytext); }
+<EXPR>0x[0-7a-f]		{ printf("NUMBER (hex) %s\n", yytext); }
+<EXPR>([1-9][0-9]*|0)		{ printf("NUMBER (dec) %s\n", yytext);
+				  yylval.n = atoll(yytext); return NUMBER; }
+<EXPR>\$[$!]{0,1}[a-z][a-z0-9\-_\.]*	{ printf("VARNAME: '%s'\n", yytext); return VAR; }
+<EXPR>\'([^'\\]|\\['])*\'	 { printf("EXPR string: -%s-\n", yytext); return STRING; }
 <EXPR>[ \t\n]
 <EXPR>.				{ printf("invalid char in expr: %s\n", yytext); }
 "&"				{ return '&'; }
diff --git a/grammar/rscript.y b/grammar/rscript.y
index 7e9365c5..3b680990 100644
--- a/grammar/rscript.y
+++ b/grammar/rscript.y
@@ -8,11 +8,13 @@
 
 %union {
 	char *s;
+	long long n;
 	es_str_t *estr;
 	enum cnfobjType objType;
 	struct cnfobj *obj;
 	struct nvlst *nvlst;
 	struct cnfactlst *actlst;
+	struct cnfexpr *expr;
 }
 
 %token <estr> NAME
@@ -26,7 +28,12 @@
 %token <s> PROPFILT
 %token IF
 %token THEN
-%token NUMBER
+%token OR
+%token AND
+%token NOT
+%token VAR
+%token <estr> STRING
+%token <n> NUMBER
 
 %type <nvlst> nv nvlst
 %type <obj> obj
@@ -34,6 +41,12 @@
 %type <actlst> act
 %type <s> cfsysline
 %type <actlst> block
+%type <expr> expr
+
+%left AND OR
+%left '+' '-'
+%left '*' '/' '%'
+%nonassoc UMINUS NOT
 
 %expect 3
 /* two shift/reduce conflicts are created by the CFSYSLINE construct, which we
@@ -72,7 +85,7 @@ rule:	  PRIFILT actlst		{ printf("PRIFILT: %s\n", $1); free($1);
 	| PROPFILT actlst
 	| scriptfilt
 
-scriptfilt: IF NUMBER THEN actlst	{ printf("if filter detected\n"); }
+scriptfilt: IF expr THEN actlst	{ printf("if filter detected, expr:\n"); cnfexprPrint($2,0); }
 
 /* note: we can do some limited block-structuring with the v6 engine. In that case,
  * we must not support additonal filters inside the blocks, so they must consist of
@@ -94,6 +107,17 @@ act:	  BEGIN_ACTION nvlst ENDOBJ	{ $$ = cnfactlstNew(CNFACT_V2, $2, NULL); }
 	| LEGACY_ACTION			{ printf("legacy action: '%s'\n", $1);
 					  $$ = cnfactlstNew(CNFACT_LEGACY, NULL, $1); }
 
+expr:	  expr '+' expr			{ $$ = cnfexprNew('+', $1, $3); }
+	| expr '-' expr			{ $$ = cnfexprNew('-', $1, $3); }
+	| expr '*' expr			{ $$ = cnfexprNew('*', $1, $3); }
+	| expr '/' expr			{ $$ = cnfexprNew('/', $1, $3); }
+	| expr '%' expr			{ $$ = cnfexprNew('%', $1, $3); }
+	| '(' expr ')'			{ $$ = $2; printf("( expr)\n"); }
+	| '-' expr %prec UMINUS		{ printf("uminus\n"); $$ = cnfexprNew('M', NULL, $2); }
+	| NUMBER			{ $$ = cnfnumvalNew($1); }
+	| STRING			{ $$ = cnfstringvalNew($1); }
+	| VAR				{ printf("variables not yet implemented!\n"); }
+
 %%
 int yyerror(char *s)
 {
diff --git a/grammar/utils.c b/grammar/utils.c
index 28e1a04a..c26a856c 100644
--- a/grammar/utils.c
+++ b/grammar/utils.c
@@ -8,11 +8,9 @@
 void
 readConfFile(FILE *fp, es_str_t **str)
 {
-	int c;
 	char ln[10240];
 	int len, i;
 	int start;	/* start index of to be submitted text */
-	char *fgetsRet;
 	int bContLine = 0;
 
 	*str = es_newStr(4096);
@@ -177,7 +175,7 @@ cnfcfsyslinelstReverse(struct cnfcfsyslinelst *lst)
 	struct cnfcfsyslinelst *curr, *prev;
 
 	if(lst == NULL)
-		return;
+		return NULL;
 	prev = lst;
 	lst = lst->next;
 	prev->next = NULL;
@@ -231,6 +229,75 @@ cnfactlstPrint(struct cnfactlst *actlst)
 	printf("----------\n");
 }
 
+struct cnfexpr*
+cnfexprNew(int nodetype, struct cnfexpr *l, struct cnfexpr *r)
+{
+	struct cnfexpr *expr;
+	if((expr = malloc(sizeof(struct cnfexpr))) != NULL) {
+		expr->nodetype = nodetype;
+		expr->l = l;
+		expr->r = r;
+	}
+	return expr;
+}
+
+
+inline static void
+doIndent(indent)
+{
+	int i;
+	for(i = 0 ; i < indent ; ++i)
+		printf("  ");
+}
+void
+cnfexprPrint(struct cnfexpr *expr, int indent)
+{
+	//printf("expr %p, indent %d, type '%c'\n", expr, indent, expr->nodetype);
+	switch(expr->nodetype) {
+	case 'N':
+		doIndent(indent);
+		printf("%lld\n", ((struct cnfnumval*)expr)->val);
+		break;
+	case '+':
+	case '-':
+	case '*':
+	case '/':
+	case '%':
+	case 'M':
+		if(expr->l != NULL)
+			cnfexprPrint(expr->l, indent+1);
+		doIndent(indent);
+		printf("%c\n", (char) expr->nodetype);
+		cnfexprPrint(expr->r, indent+1);
+		break;
+	default:
+		printf("error: unknown nodetype\n");
+		break;
+	}
+}
+
+struct cnfnumval*
+cnfnumvalNew(long long val)
+{
+	struct cnfnumval *numval;
+	if((numval = malloc(sizeof(struct cnfnumval))) != NULL) {
+		numval->nodetype = 'N';
+		numval->val = val;
+	}
+	return numval;
+}
+
+struct cnfstringval*
+cnfstringvalNew(es_str_t *estr)
+{
+	struct cnfstringval *strval;
+	if((strval = malloc(sizeof(struct cnfstringval))) != NULL) {
+		strval->nodetype = 'S';
+		strval->estr = estr;
+	}
+	return strval;
+}
+
 /* debug helper */
 void
 cstrPrint(char *text, es_str_t *estr)
diff --git a/grammar/utils.h b/grammar/utils.h
index 2a6ba10a..a402d4b2 100644
--- a/grammar/utils.h
+++ b/grammar/utils.h
@@ -58,6 +58,30 @@ struct cnfactlst {
 	} data;
 };
 
+/* the following structures support expressions, and may (very much later
+ * be the sole foundation for the AST.
+ */
+struct cnfexpr {
+	int nodetype;
+	struct cnfexpr *l;
+	struct cnfexpr *r;
+};
+
+struct cnfnumval {
+	int nodetype;
+	long long val;
+};
+
+struct cnfstringval {
+	int nodetype;
+	es_str_t *estr;
+};
+
+/* future extensions
+struct x {
+	int nodetype;
+};
+*/
 
 void readConfFile(FILE *fp, es_str_t **str);
 struct nvlst* nvlstNew(es_str_t *name, es_str_t *value);
@@ -71,6 +95,10 @@ void cnfactlstDestruct(struct cnfactlst *actlst);
 void cnfactlstPrint(struct cnfactlst *actlst);
 struct cnfactlst* cnfactlstAddSysline(struct cnfactlst* actlst, char *line);
 struct cnfactlst* cnfactlstReverse(struct cnfactlst *actlst);
+struct cnfexpr* cnfexprNew(int nodetype, struct cnfexpr *l, struct cnfexpr *r);
+void cnfexprPrint(struct cnfexpr *expr, int indent);
+struct cnfnumval* cnfnumvalNew(long long val);
+struct cnfstringval* cnfstringvalNew(es_str_t *estr);
 
 /* debug helper */
 void cstrPrint(char *text, es_str_t *estr);