Filter: Implement direct recursion (77c41a72) · Commits · 戴 / Bird

filter/config.Y

+13 −10

Original line number	Diff line number	Diff line
		@@ -460,25 +460,28 @@ function_body:

		conf: function_def ;
		function_def:
		FUNCTION symbol { DBG( "Beginning of function %s\n", $2->name );
		FUNCTION symbol {
		DBG( "Beginning of function %s\n", $2->name );
		$2 = cf_define_symbol($2, SYM_FUNCTION, function, NULL);
		cf_push_scope($2);
		} function_args function_body
		{
		$5->arg_list = NULL;
		$5->args = 0;
		} function_args {
		/* Make dummy f_line for storing function prototype */
		struct f_line *dummy = cfg_allocz(sizeof(struct f_line));
		$2->function = dummy;

		/* Revert the args */
		while ($4) {
		struct f_arg *tmp = $4;
		$4 = $4->next;

		tmp->next = $5->arg_list;
		$5->arg_list = tmp;
		$5->args++;
		tmp->next = dummy->arg_list;
		dummy->arg_list = tmp;
		dummy->args++;
		}

		$2->function = $5;
		} function_body {
		$6->args = $2->function->args;
		$6->arg_list = $2->function->arg_list;
		$2->function = $6;
		cf_pop_scope();
		}
		;

filter/decl.m4

+2 −0

Original line number	Diff line number	Diff line
		@@ -376,6 +376,7 @@ case INST_NAME(): {
		#undef whati
		#undef item
		dest->items[pos].fi_code = what->fi_code;
		dest->items[pos].flags = what->flags;
		dest->items[pos].lineno = what->lineno;
		break;
		}
		@@ -647,6 +648,7 @@ FID_WR_PUT(4)m4_dnl
		struct f_inst {
		struct f_inst next; / Next instruction */
		enum f_instruction_code fi_code; /* Instruction code */
		enum f_instruction_flags flags; /* Flags, instruction-specific */
		enum f_type type; /* Type of returned value, if known */
		int size; /* How many instructions are underneath */
		int lineno; /* Line number */

filter/f-inst.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -1165,11 +1165,16 @@
		whati->fvar = tmp;
		what->size += tmp->size;

		/* Mark recursive calls, they have dummy f_line */
		if (!sym->function->len)
		what->flags \|= FIF_RECURSIVE;

		FID_SAME_BODY()
		if (!(f1->sym->flags & SYM_FLAG_SAME))
		if (!(f1->sym->flags & SYM_FLAG_SAME) && !(f1_->flags & FIF_RECURSIVE))
		return 0;

		FID_ITERATE_BODY()
		if (!(what->flags & FIF_RECURSIVE))
		BUFFER_PUSH(fit->lines) = whati->sym->function;

		FID_INTERPRET_BODY()

filter/f-inst.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -22,7 +22,7 @@

		/* Flags for instructions */
		enum f_instruction_flags {
		FIF_PRINTED = 1, /* FI_PRINT_AND_DIE: message put in buffer */
		FIF_RECURSIVE = 1, /* FI_CALL: function is directly recursive */
		} PACKED;

		/* Include generated filter instruction declarations */

filter/test.conf

+63 −0

Original line number	Diff line number	Diff line
		@@ -1290,7 +1290,60 @@ function fifteen()
		return 15;
		}

		function factorial(int x)
		{
		if x = 0 then return 0;
		if x = 1 then return 1;
		else return x * factorial(x - 1);
		}

		function fibonacci(int x)
		{
		if x = 0 then return 0;
		if x = 1 then return 1;
		else return fibonacci(x - 1) + fibonacci(x - 2);
		}

		function hanoi_init(int a; int b)
		{
		if b = 0
		then return +empty+;
		else return prepend(hanoi_init(a + 1, b - 1), a);
		}

		function hanoi_solve(int n; bgppath h_src; bgppath h_dst; bgppath h_aux; bool x; bool y)
		bgppath tmp1;
		bgppath tmp2;
		int v;
		{
		# x -> return src or dst
		# y -> print state

		if n = 0 then { if x then return h_src; else return h_dst; }

		tmp1 = hanoi_solve(n - 1, h_src, h_aux, h_dst, true, y);
		tmp2 = hanoi_solve(n - 1, h_src, h_aux, h_dst, false, false);
		h_src = tmp1;
		h_aux = tmp2;

		v = h_src.first;
		# bt_assert(h_dst = +empty+ \|\| v < h_dst.first);
		h_src = delete(h_src, v);
		h_dst = prepend(h_dst, v);

		if y then
		print "move: ", v, " src: ", h_src, " dst:", h_dst, " aux:", h_aux;

		tmp1 = hanoi_solve(n - 1, h_aux, h_dst, h_src, true, y);
		tmp2 = hanoi_solve(n - 1, h_aux, h_dst, h_src, false, false);
		h_aux = tmp1;
		h_dst = tmp2;

		if x then return h_src; else return h_dst;
		}

		function t_call_function()
		bgppath h_src;
		{
		bt_assert(fifteen() = 15);

		@@ -1302,6 +1355,16 @@ function t_call_function()
		bt_assert(callme(4, 4) = 16);
		bt_assert(callme(7, 2) = 14);
		bt_assert(callmeagain(1, 2, 3) = 6);

		bt_assert(factorial(5) = 120);
		bt_assert(factorial(10) = 3628800);

		bt_assert(fibonacci(10) = 55);
		bt_assert(fibonacci(20) = 6765);

		h_src = hanoi_init(1, 6);
		bt_assert(format(h_src) = "(path 1 2 3 4 5 6)");
		bt_assert(hanoi_solve(6, h_src, +empty+, +empty+, false, false) = h_src);
		}

		bt_test_suite(t_call_function, "Testing calling functions");

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