add back the include() function to awk (extracted from the old awx patch)

SVN-Revision: 13081

package/busybox/patches/510-awk_include.patch

@@ -0,0 +1,212 @@
+--- a/editors/awk.c
++++ b/editors/awk.c
+@@ -53,9 +53,14 @@ typedef struct chain_s {
+ } chain;
+ 
+ /* Function */
++typedef var *(*awk_cfunc)(var *res, var *args, int nargs);
+ typedef struct func_s {
+ 	unsigned nargs;
++	enum { AWKFUNC, CFUNC } type;
++	union {
++		awk_cfunc cfunc;
+ 	struct chain_s body;
++	} x;
+ } func;
+ 
+ /* I/O stream */
+@@ -1395,7 +1400,8 @@ static void parse_program(char *p)
+ 			next_token(TC_FUNCTION);
+ 			g_pos++;
+ 			f = newfunc(t_string);
+-			f->body.first = NULL;
++			f->type = AWKFUNC;
++			f->x.body.first = NULL;
+ 			f->nargs = 0;
+ 			while (next_token(TC_VARIABLE | TC_SEQTERM) & TC_VARIABLE) {
+ 				v = findvar(ahash, t_string);
+@@ -1404,7 +1410,7 @@ static void parse_program(char *p)
+ 				if (next_token(TC_COMMA | TC_SEQTERM) & TC_SEQTERM)
+ 					break;
+ 			}
+-			seq = &(f->body);
++			seq = &(f->x.body);
+ 			chain_group();
+ 			clear_array(ahash);
+ 
+@@ -2367,7 +2373,8 @@ static var *evaluate(node *op, var *res)
+ 			break;
+ 
+ 		case XC( OC_FUNC ):
+-			if (!op->r.f->body.first)
++			if ((op->r.f->type == AWKFUNC) &&
++				!op->r.f->x.body.first)
+ 				syntax_error(EMSG_UNDEF_FUNC);
+ 
+ 			X.v = R.v = nvalloc(op->r.f->nargs+1);
+@@ -2384,7 +2391,10 @@ static var *evaluate(node *op, var *res)
+ 			fnargs = X.v;
+ 
+ 			L.s = g_progname;
+-			res = evaluate(op->r.f->body.first, res);
++			if (op->r.f->type == AWKFUNC)
++				res = evaluate(op->r.f->x.body.first, res);
++			else if (op->r.f->type == CFUNC)
++				res = op->r.f->x.cfunc(res, fnargs, op->r.f->nargs);
+ 			g_progname = L.s;
+ 
+ 			nvfree(fnargs);
+@@ -2747,6 +2757,143 @@ static rstream *next_input_file(void)
+ #undef files_happen
+ }
+ 
++/* read the contents of an entire file */
++static char *get_file(const char *fname)
++{
++	FILE *F;
++	char *s = NULL;
++	int i, j, flen;
++
++	F = fopen(fname, "r");
++	if (!F) {
++		return NULL;
++	}
++
++	if (fseek(F, 0, SEEK_END) == 0) {
++		flen = ftell(F);
++		s = (char *)xmalloc(flen+4);
++		fseek(F, 0, SEEK_SET);
++		i = 1 + fread(s+1, 1, flen, F);
++	} else {
++		for (i=j=1; j>0; i+=j) {
++			s = (char *)xrealloc(s, i+4096);
++			j = fread(s+i, 1, 4094, F);
++		}
++	}
++
++	s[i] = '\0';
++	fclose(F);
++	return s;
++}
++
++
++/* parse_include():
++ *
++ * taken from parse_program from awk.c
++ * END{} is not parsed here, and BEGIN{} is executed immediately
++ */
++static void parse_include(char *p)
++{
++	uint32_t tclass;
++	chain *initseq = NULL;
++	chain tmp;
++	func *f;
++	var *v, *tv;
++
++	tv = nvalloc(1);
++	memset(&tmp, 0, sizeof(tmp));
++	g_pos = p;
++	t_lineno = 1;
++	while ((tclass = next_token(TC_EOF | TC_OPSEQ |
++				TC_OPTERM | TC_BEGIN | TC_FUNCDECL)) != TC_EOF) {
++		if (tclass & TC_OPTERM)
++			continue;
++
++		seq = &tmp;
++		if (tclass & TC_BEGIN) {
++			initseq = xzalloc(sizeof(chain));
++			seq = initseq;
++			chain_group();
++		} else if (tclass & TC_FUNCDECL) {
++			next_token(TC_FUNCTION);
++			g_pos++;
++			f = newfunc(t_string);
++			f->type = AWKFUNC;
++			f->x.body.first = NULL;
++			f->nargs = 0;
++			while (next_token(TC_VARIABLE | TC_SEQTERM) & TC_VARIABLE) {
++				v = findvar(ahash, t_string);
++				v->x.aidx = (f->nargs)++;
++
++				if (next_token(TC_COMMA | TC_SEQTERM) & TC_SEQTERM)
++					break;
++			}
++			seq = &(f->x.body);
++			chain_group();
++			clear_array(ahash);
++		}
++	}
++	if (initseq && initseq->first)
++		tv = evaluate(initseq->first, tv);
++	nvfree(tv);
++}
++
++
++/* include an awk file and run its BEGIN{} section */
++static xhash *includes = NULL;
++static void include_file(const char *filename)
++{
++	char *s;
++	var *v;
++	int oldlnr = g_lineno;
++	const char *oldprg = g_progname;
++
++	if (!includes)
++		includes = hash_init();
++
++	/* find out if the file has been included already */
++	v = findvar(includes, filename);
++	if (istrue(v))
++		return;
++	setvar_s(v, "1");
++
++	/* read include file */
++	s = get_file(filename);
++	if (!s) {
++		fprintf(stderr, "Could not open file.\n");
++		return;
++	}
++	g_lineno = 1;
++	g_progname = xstrdup(filename);
++	parse_include(s+1);
++	free(s);
++	g_lineno = oldlnr;
++	g_progname = oldprg;
++}
++
++static var *include(var *res, var *args, int nargs)
++{
++	const char *s;
++
++	nargs = nargs; /* shut up, gcc */
++	s = getvar_s(args);
++	if (s && (strlen(s) > 0))
++		include_file(s);
++
++	return res;
++}
++
++/* registers a global c function for the awk interpreter */
++static void register_cfunc(const char *name, awk_cfunc cfunc, int nargs)
++{
++	func *f;
++
++	f = newfunc(name);
++	f->type = CFUNC;
++	f->x.cfunc = cfunc;
++	f->nargs = nargs;
++}
++
+ int awk_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+ int awk_main(int argc, char **argv)
+ {
+@@ -2812,6 +2959,9 @@ int awk_main(int argc, char **argv)
+ 			*s1 = '=';
+ 		}
+ 	}
++
++	register_cfunc("include", include, 1);
++
+ 	opt_complementary = "v::f::"; /* -v and -f can occur multiple times */
+ 	opt = getopt32(argv, "F:v:f:W:", &opt_F, &list_v, &list_f, &opt_W);
+ 	argv += optind;