handle variadic functions

main.leg

@@ -1,6 +1,6 @@
 # main.leg -- C parser + interpreter
 #
-# Last edited: 2025-01-22 11:03:33 by piumarta on zora
+# Last edited: 2025-01-22 11:44:37 by piumarta on zora
 
 %{
 ;
@@ -114,7 +114,7 @@ struct Scope	 { type_t _type;  oop names, types, values; };
 struct TypeName	 { type_t _type;  oop name, type; };
 struct Variable	 { type_t _type;  oop name, type, value; };
 struct Constant	 { type_t _type;  oop name, type, value; };
-struct Function	 { type_t _type;  oop name, type, parameters, body, *code; };
+struct Function	 { type_t _type;  oop name, type, parameters, body, *code;  int variadic; };
 struct Primitive { type_t _type;  oop name, type; prim_t function; };
 struct VarDecls	 { type_t _type;  oop type, declarations, variables; };
 
@@ -589,6 +589,8 @@ oop newTbase(char *name, int size)
     return obj;
 }
 
+oop s_etc    = 0;
+oop t_etc    = 0;
 oop t_void   = 0;
 oop t_char   = 0;
 oop t_int    = 0;
@@ -723,6 +725,7 @@ oop newFunction(oop name, oop type, oop parameters, oop body)
     obj->Function.parameters = parameters;
     obj->Function.body       = body;
     obj->Function.code       = 0;
+    obj->Function.variadic   = 0;
     return obj;
 }
 
@@ -817,6 +820,7 @@ oop baseType(oop type)
 	case Tbase:	return type;
 	case Tpointer:	return baseType(get(type, Tpointer,target));
 	case Tarray:	return baseType(get(type, Tarray,target));
+	case Tfunction:	return baseType(get(type, Tfunction,result));
 	default:
 	    fatal("cannot find base type of %s", getTypeName(type));
     }
@@ -904,10 +908,8 @@ oop toStringOn(oop obj, oop str)
 	    oop type = get(obj, Variable,type);
 	    oop name = get(obj, Variable,name);
 	    toStringOn(baseType(type), str);
-	    if (t_void != type) {
-		String_append(str, ' ');
-		declareStringOn(type, name, str);
-	    }
+	    String_append(str, ' ');
+	    declareStringOn(type, name, str);
 	    break;
 	}
 	case Function: {
@@ -1142,7 +1144,7 @@ void printiln(oop obj, int indent)
 	    break;
 	}
 	case Variable: {
-	    printf("Variable\n");
+	    printf("Variable %s\n", toString(obj));
 	    printiln(get(obj, Variable,name ), indent+1);
 	    printiln(get(obj, Variable,type ), indent+1);
 	    printiln(get(obj, Variable,value), indent+1);
@@ -1286,7 +1288,8 @@ ddector	= ( LPAREN d:decltor RPAREN
 params	= LPAREN a:mkArray
 	  ( p:pdecl			{ Array_append(a, p) }
 	    ( COMMA p:pdecl		{ Array_append(a, p) }
-	    )* )? ( RPAREN		{ $$ = a }
+	    )* )? ( ( COMMA ETC		{ Array_append(a, t_etc) }
+	       	    )? RPAREN		{ $$ = a }
 	       	  | e:error		{ expected(e, "parameter declaration") }
 		  )
 
@@ -1459,7 +1462,6 @@ blank	= [ \t\n\r] | comment
 comment = "//" < (![\n\r] .)* >
 	| "/*" (!"*/" .)* "*/"
 
-HASH    = "#"           -
 INCLUDE	= "include"  ![_a-zA-Z0-9] -
 VOID	= "void"     ![_a-zA-Z0-9] -
 CHAR	= "char"     ![_a-zA-Z0-9] -
@@ -1474,6 +1476,8 @@ FOR	= "for"      ![_a-zA-Z0-9] -
 RETURN	= "return"   ![_a-zA-Z0-9] -
 CONTINU = "continue" ![_a-zA-Z0-9] -
 BREAK	= "break"    ![_a-zA-Z0-9] -
+ETC     = "..."         -
+HASH    = "#"           -
 ASSIGN	= "=" !"="	-
 PLUS	= "+" !"+"	-
 PPLUS	= "++"		-
@@ -1573,10 +1577,18 @@ oop apply(oop function, oop arguments, oop env)
 	    oop *parv = get(parameters, Array,elements);
 	    oop *argv = get(arguments,  Array,elements);
 	    Scope_begin();
-	    for (int i = 0;  i < argc;  ++i) {
-		oop var = parv[i];
-		oop arg = argv[i];
+	    if (get(function, Function,variadic)) --parc;
+	    int  argn = 0;
+	    while (argn < parc) {
+		oop var = parv[argn];
+		oop arg = argv[argn];
 		defineVariable(get(var, Variable,name), get(var, Variable,type), eval(arg, nil));
+		++argn;
+	    }
+	    if (argn < argc) { // put varargs array in local variable called "..."
+		oop etc = newArray();
+		while (argn < argc) Array_append(etc, eval(argv[argn++], nil));
+		defineVariable(s_etc, t_etc, etc);
 	    }
 	    switch (nlrPush()) { // longjmp occurred
 		case NLR_INIT:     break;
@@ -1891,7 +1903,7 @@ oop prim_printf(int argc, oop *argv, oop env) // array
 	    switch (c) {
 		case 'd': {
 		    if (argn >= argc)
-			fatal("not enough argments for printf format string");
+			fatal("too few arguments for printf format string");
 		    arg = argv[argn++];
 		    if (!is(Integer, arg))
 			fatal("%%d conversion argument is %s", getTypeName(arg));
@@ -1904,6 +1916,7 @@ oop prim_printf(int argc, oop *argv, oop env) // array
 	putchar(c);
 	++n;
     }
+    if (argn != argc) fatal("too many arguments for printf format string");
     return newInteger(n);
 }
 
@@ -2400,6 +2413,11 @@ oop typeCheck(oop exp, oop fntype)
 		oop type = get(var, Variable,type);
 		if (t_void == type && (do_index || do_size > 1))
 		    fatal("illegal void parameter");
+		else if (t_etc == type) {
+		    if (do_index == 0 || do_index != do_size - 1)
+			fatal("illegal varargs parameter");
+		    set(exp, Function,variadic, 1);
+		}
 		Array_append(ptypes, type);
 	    }
 	    if (1 == Array_size(ptypes) && Array_last(ptypes) == t_void) {
@@ -2433,9 +2451,12 @@ oop typeCheck(oop exp, oop fntype)
 	    oop *argv   = get(arguments, Array,elements);
 	    int  parc   = get(params, Array,size);
 	    oop *parv   = get(params, Array,elements);
-	    if (argc != parc) fatal("wrong number (%d) of arguments, expected %d", argc, parc);
+	    int  vararg = parc && t_etc == parv[parc - 1];
+	    if ((vararg && (argc < parc)) || (!vararg && (argc != parc)))
+		fatal("wrong number (%d %d) of arguments, expected %d", vararg, argc, parc);
 	    for (int i = 0;  i < argc;  ++i) {
 		oop part = parv[i];
+		if (part == t_etc) break;
 		oop arg  = argv[i];
 		oop argt = typeCheck(arg, fntype);
 		if (argt != part)
@@ -2531,7 +2552,9 @@ void replFile(char *name, FILE *file)
 			case NLR_CONTINUE: fatal("continue outside loop");
 			case NLR_BREAK:    fatal("break outside loop");
 		    }
+		    if (opt_v > 1) printf("---------------- typecheck\n");
 		    typeCheck(yysval, nil);
+		    if (opt_v > 1) printf("---------------- eval\n");
 		    result = eval(yysval, nil);
 		    nlrPop();
 		}
@@ -2552,8 +2575,10 @@ void replPath(char *path)
 
 int main(int argc, char **argv)
 {
-    true      = newSymbol("true");
+    true     = newSymbol("true");
+    s_etc    = newSymbol("...");
 
+    t_etc    = newTbase("...",   0);
     t_void   = newTbase("void",  1);
     t_char   = newTbase("char",  1);
     t_int    = newTbase("int",   4);
@@ -2565,7 +2590,7 @@ int main(int argc, char **argv)
     Scope_begin(); // the global scope
 
     definePrimitive(intern("printf"),
-		    newTfunction(t_int, newArray2(t_string, t_int)),
+		    newTfunction(t_int, newArray2(t_string, t_etc)),
 		    prim_printf);
 
     int repls = 0;

test.txt

@@ -2,14 +2,12 @@
 
 #include <stdio.h>
 
-int foo(void)
-{
-    return 42;
-}
+int foo(void) { return 42; }
+int bar(void) { return 99; }
 
 int main(int argc, char **argv)
 {
-    printf("hello, world %d\n", foo());
+    printf("hello, world %d %d\n", foo(), bar());
     return 0;
 }