fixed a wrong assertion

hawk.go

@@ -701,7 +701,7 @@ func (rtx *Rtx) Exec(args []string) (*Val, error) {
 	// hawk_rtx_exec...() returns a value with the reference count incremented.
 	// create a value without going through rtx.make_val()
 	return rtx.fix_val_with_raw(val), nil
-	//return rtx.make_val(func() *C.hawk_val_t { return val })
+	//return rtx.make_val(func() *C.hawk_val_t { return val })aAAA
 }
 
 func (rtx *Rtx) Loop() (*Val, error) {
@@ -711,7 +711,7 @@ func (rtx *Rtx) Loop() (*Val, error) {
 	// hawk_rtx_loop() returns a value with the reference count incremented.
 	// create a value without going through rtx.make_val()
 	return rtx.fix_val_with_raw(val), nil
-	//return rtx.make_val(func() *C.hawk_val_t { return val })
+	//return rtx.make_val(func() *C.hawk_val_t { return val })aAAA
 }
 
 func (rtx *Rtx) Call(name string, args ...*Val) (*Val, error) {
@@ -1053,8 +1053,7 @@ func (rtx* Rtx) fix_val_with_raw(val *C.hawk_val_t) *Val {
 	// this function assumes val has the non-zero reference count
 	// the caller must ensure that the reference count has been incremented properly
 	var vv *Val
-	// immediate values or static pointer values must no check the reference count.
-	if C.hawk_rtx_isimmorstaticval(rtx.c, val) == 0 && val.v_refs <= 0 { panic("invalid reference count") }
+	if val.v_refs <= 0 && C.hawk_rtx_isstaticval(rtx.c, val) == 0  { panic("invalid reference count") }
 	vv = &Val{rtx: rtx, c: val}
 	rtx.chain_val(vv)
 	return vv

lib/hawk-prv.h

@@ -69,6 +69,20 @@ typedef struct hawk_tree_t hawk_tree_t;
 #define HAWK_ENABLE_ATOMIC_SIG
 #endif
 
+/* this part is kept for preservation of experiment only.
+#if defined(HAVE_UCONTEXT_H)
+#include <ucontext.h>
+#define HAWK_ENABLE_UCONTEXT
+#endif
+*/
+
+/* Use iterative (heap-stack) expression evaluation instead of C recursion.
+ * eval_expression, eval_expression0, and hawk_rtx_evalcall automatically
+ * route through the xstack variants when this is defined. Comment out to
+ * revert to the purely recursive implementation. */
+/*#define HAWK_ENABLE_XSTACK_EVAL*/
+
+
 /* ------------------------------------------------------------------------ */
 
 /* private headers. some files are affected by feature macros above */
@@ -448,6 +462,49 @@ struct hawk_exec_stack_t
 
 typedef struct hawk_exec_stack_t hawk_exec_stack_t;
 
+/* expression frame states for eval_expression0_xstack */
+enum hawk_ef_state_t
+{
+	HAWK_EF_EVAL = 0,       /* dispatch on nde->type */
+	HAWK_EF_BIN_LEFT,       /* binary: awaiting left result */
+	HAWK_EF_BIN_RIGHT,      /* binary: left done (val=left refupped), awaiting right */
+	HAWK_EF_UNARY,          /* unary: awaiting operand result */
+	HAWK_EF_CND,            /* conditional: awaiting test result */
+	HAWK_EF_ASS_RHS,        /* assignment: awaiting RHS result */
+	HAWK_EF_ASS_LHS,        /* compound assign: RHS in val (refupped), awaiting LHS */
+	HAWK_EF_LAND_LEFT,      /* logical AND: awaiting left result */
+	HAWK_EF_LAND_RIGHT,     /* logical AND: left done and true (val=left), awaiting right */
+	HAWK_EF_LOR_LEFT,       /* logical OR: awaiting left result */
+	HAWK_EF_LOR_RIGHT,      /* logical OR: left done and false (val=left), awaiting right */
+#if defined(HAWK_ENABLE_XSTACK_EVAL)
+	HAWK_EF_FNCALL_FUN_AWAIT /* user fn body executing on exec_stack; aux=exec_body_base */
+#endif
+};
+typedef enum hawk_ef_state_t hawk_ef_state_t;
+
+struct hawk_eframe_t
+{
+	hawk_ef_state_t state;
+	hawk_nde_t*     nde;  /* composite node being processed */
+	hawk_val_t*     val;  /* intermediate value (refcount incremented) */
+	hawk_oow_t      aux;  /* FNCALL_FUN_AWAIT: exec_stack size when body frames were pushed */
+};
+typedef struct hawk_eframe_t hawk_eframe_t;
+
+#if defined(HAWK_ENABLE_XSTACK_EVAL)
+/* call frame: saves context for a user-defined function call made from within
+ * expression evaluation. stored in the call_stack. */
+struct hawk_call_frame_t
+{
+	hawk_nde_fncall_t* call;            /* call-site node */
+	hawk_fun_t*        fun;             /* resolved function */
+	hawk_oow_t         saved_stack_top; /* rtx->stack_top before the call */
+	hawk_oow_t         saved_stack_base;/* rtx->stack_base before the call */
+	hawk_oow_t         nargs;           /* actual argument count pushed */
+};
+typedef struct hawk_call_frame_t hawk_call_frame_t;
+#endif
+
 struct hawk_rtx_t
 {
 	HAWK_RTX_HDR;
@@ -467,6 +524,36 @@ struct hawk_rtx_t
 	hawk_oow_t exec_stack_size;
 	hawk_oow_t exec_stack_limit;
 
+	/* heap-based stack for iterative expression evaluation (xstack variant) */
+	hawk_eframe_t* eframe_stack;
+	hawk_oow_t eframe_stack_size;
+	hawk_oow_t eframe_stack_limit;
+
+#if defined(HAWK_ENABLE_XSTACK_EVAL)
+	/* heap-based call frame stack: user-defined function calls from eframe evaluation */
+	hawk_call_frame_t* call_stack;
+	hawk_oow_t call_stack_size;
+	hawk_oow_t call_stack_limit;
+	/* result register: eframe eval result delivered to exec AFTER_EVAL frames */
+	hawk_val_t* driver_eval_result;
+#endif
+
+#if defined(HAWK_ENABLE_UCONTEXT)
+	/* pool of reusable C stacks for coroutine-based function calls */
+	struct
+	{
+		char* pool[16];
+		hawk_oow_t pool_size;
+		/* arguments for the next coroutine invocation */
+		hawk_nde_blk_t* pending_body;
+		int*            pending_result;
+		/* depth at which the current C stack segment started */
+		hawk_oow_t      stack_base;
+		/* nonzero when executing on a heap-allocated coroutine stack */
+		int             in_coroutine;
+	} co;
+#endif
+
 	int exit_level;
 	int init_called;
 

lib/hawk.h

@@ -1922,12 +1922,14 @@ static HAWK_INLINE void hawk_geterruinf (hawk_t* hawk, hawk_erruinf_t* errinf) {
  * it automatically formatted.
  */
 #if defined(HAWK_HAVE_INLINE)
-static HAWK_INLINE void hawk_seterrnum (hawk_t* hawk, const hawk_loc_t* errloc, hawk_errnum_t errnum) { hawk_gem_seterrnum (hawk_getgem(hawk), errloc, errnum); }
-static HAWK_INLINE void hawk_seterrinf (hawk_t* hawk, const hawk_errinf_t* errinf) { hawk_gem_seterrinf (hawk_getgem(hawk), errinf); }
+static HAWK_INLINE void hawk_clrerror (hawk_t* hawk) { hawk_gem_seterrnum(hawk_getgem(hawk), HAWK_NULL, HAWK_ENOERR); }
+static HAWK_INLINE void hawk_seterrnum (hawk_t* hawk, const hawk_loc_t* errloc, hawk_errnum_t errnum) { hawk_gem_seterrnum(hawk_getgem(hawk), errloc, errnum); }
+static HAWK_INLINE void hawk_seterrinf (hawk_t* hawk, const hawk_errinf_t* errinf) { hawk_gem_seterrinf(hawk_getgem(hawk), errinf); }
 static HAWK_INLINE void hawk_seterror (hawk_t* hawk, const hawk_loc_t*  errloc, hawk_errnum_t errnum, const hawk_oocs_t* errarg) { hawk_gem_seterror(hawk_getgem(hawk), errloc, errnum, errarg); }
 static HAWK_INLINE const hawk_ooch_t* hawk_backuperrmsg (hawk_t* hawk) { return hawk_gem_backuperrmsg(hawk_getgem(hawk)); }
 static HAWK_INLINE void hawk_geterror (hawk_t* hawk, hawk_errnum_t* errnum, const hawk_ooch_t** errmsg, hawk_loc_t* errloc) { return hawk_gem_geterror(hawk_getgem(hawk), errnum, errmsg, errloc); }
 #else
+#define hawk_clrerror(hawk) hawk_gem_seterrnum(hawk_getgem(hawk), HAWK_NULL, HAWK_ENOERR)
 #define hawk_seterrnum(hawk, errloc, errnum) hawk_gem_seterrnum(hawk_getgem(hawk), errloc, errnum)
 #define hawk_seterrinf(hawk, errinf) hawk_gem_seterrinf(hawk_getgem(hawk), errinf)
 #define hawk_seterror(hawk, errloc, errnum, errarg) hawk_gem_seterror(hawk_getgem(hawk), errloc, errnum, errarg)
@@ -3119,11 +3121,13 @@ static HAWK_INLINE void hawk_rtx_geterror (hawk_rtx_t* rtx, hawk_errnum_t* errnu
  * The hawk_rtx_seterrinf() function sets error information.
  */
 #if defined(HAWK_HAVE_INLINE)
+static HAWK_INLINE void hawk_rtx_clrerror (hawk_rtx_t* rtx) { hawk_gem_seterrnum(hawk_rtx_getgem(rtx), HAWK_NULL, HAWK_ENOERR); }
 static HAWK_INLINE void hawk_rtx_seterrnum (hawk_rtx_t* rtx, const hawk_loc_t* errloc, hawk_errnum_t errnum) { hawk_gem_seterrnum (hawk_rtx_getgem(rtx), errloc, errnum); }
 static HAWK_INLINE void hawk_rtx_seterrinf (hawk_rtx_t* rtx, const hawk_errinf_t* errinf) { hawk_gem_seterrinf (hawk_rtx_getgem(rtx), errinf); }
 static HAWK_INLINE void hawk_rtx_seterror (hawk_rtx_t* rtx, const hawk_loc_t*  errloc, hawk_errnum_t errnum, const hawk_oocs_t* errarg) { hawk_gem_seterror(hawk_rtx_getgem(rtx), errloc, errnum, errarg); }
 static HAWK_INLINE const hawk_ooch_t* hawk_rtx_backuperrmsg (hawk_rtx_t* rtx) { return hawk_gem_backuperrmsg(hawk_rtx_getgem(rtx)); }
 #else
+#define hawk_rtx_clrerror(rtx) hawk_gem_seterrnum(hawk_rtx_getgem(rtx), HAWK_NULL, HAWK_ENOERR)
 #define hawk_rtx_seterrnum(rtx, errloc, errnum) hawk_gem_seterrnum(hawk_rtx_getgem(rtx), errloc, errnum)
 #define hawk_rtx_seterrinf(rtx, errinf) hawk_gem_seterrinf(hawk_rtx_getgem(rtx), errinf)
 #define hawk_rtx_seterror(rtx, errloc, errnum, errarg) hawk_gem_seterror(hawk_rtx_getgem(rtx), errloc, errnum, errarg)
@@ -3653,20 +3657,6 @@ HAWK_EXPORT int hawk_rtx_isstaticval (
 	const hawk_val_t* val  /**< value to check */
 );
 
-/**
- * The hawk_rtx_isimmval() function determines if a value is a immediate value
- * encoded using pointer tagging.
- */
-HAWK_EXPORT int hawk_rtx_isimmval (
-	hawk_rtx_t*       rtx, /**< runtime context */
-	const hawk_val_t* val  /**< value to check */
-);
-
-HAWK_EXPORT int hawk_rtx_isimmorstaticval (
-	hawk_rtx_t*       rtx, /**< runtime context */
-	const hawk_val_t* val  /**< value to check */
-);
-
 HAWK_EXPORT int hawk_rtx_getvaltype (
 	hawk_rtx_t*      rtx,
 	const hawk_val_t* val

lib/mod-sys.c

@@ -22,6 +22,15 @@
     THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <hawk-cfg.h>
+#if defined(HAVE_ACCEPT4)
+	/* the runtime library has accept4. but accept4 is usually visiable
+	 * if _GNU_SOURCE is defined */
+#	if !defined(_GNU_SOURCE)
+#		define _GNU_SOURCE
+#	endif
+#endif
+
 #include "mod-sys.h"
 #include "hawk-prv.h"
 #include <hawk-pio.h>
@@ -42,10 +51,6 @@
 #elif defined(__DOS__)
 #	include <dos.h>
 #else
-#	if !defined(_GNU_SOURCE)
-#		define _GNU_SOURCE
-#	endif
-
 #	include "syscall.h"
 #	include <sys/utsname.h>
 #	if defined(HAVE_SYS_EPOLL_H)

lib/run-prv.h

@@ -30,6 +30,7 @@ enum hawk_assop_type_t
 	/* if you change this, you have to change assop_str in tree.c.
 	 * synchronize it wit:
 	 *   - binop_func in eval_assignment of run.c
+	 *   - binop_func in eval_expression0_xstack in run.c
 	 *   - assop in assing_to_opcode of parse.c
 	 *   - TOK_XXX_ASSN in tok_t in parse.c
 	 *   - assop_str in tree.c
@@ -149,6 +150,18 @@ hawk_val_t* hawk_rtx_evalcall (
 	void* eharg
 );
 
+#if 0
+hawk_val_t* hawk_rtx_evalcall_xstack (
+	hawk_rtx_t* rtx,
+	hawk_nde_fncall_t* call,
+	hawk_fun_t* fun,
+	hawk_oow_t(*argpusher)(hawk_rtx_t*,const hawk_loc_t* loc,void*),
+	void* apdata,
+	void(*errhandler)(void*),
+	void* eharg
+);
+#endif
+
 int hawk_rtx_setsighandler (
 	hawk_rtx_t* rtx,
 	int         sig,

lib/val-prv.h

@@ -215,6 +215,18 @@ void hawk_rtx_freevalchunk (
 );
 
 #if defined(HAWK_HAVE_INLINE)
+/* the nocheck versions are defined in case you already know the value
+ * is a pointer and not a static value */
+static HAWK_INLINE_ALWAYS void hawk_rtx_refupval_nocheck_inline (hawk_rtx_t* rtx, hawk_val_t* val)
+{
+	#if defined(HAWK_USE_ATOMIC_REFCNT) && defined(HAWK_ATOMIC_FETCH_ADD)
+	HAWK_ATOMIC_FETCH_ADD(&val->v_refs, 1, HAWK_ATOMIC_RELAXED);
+	#else
+	val->v_refs++;
+	#endif
+}
+
+/* regular refup with pointer check */
 static HAWK_INLINE_ALWAYS void hawk_rtx_refupval_inline (hawk_rtx_t* rtx, hawk_val_t* val)
 {
 	if (HAWK_VTR_IS_POINTER(val) && !HAWK_IS_STATICVAL(val))
@@ -226,13 +238,22 @@ static HAWK_INLINE_ALWAYS void hawk_rtx_refupval_inline (hawk_rtx_t* rtx, hawk_v
 	#endif
 	}
 }
+
 #elif defined(HAWK_USE_ATOMIC_REFCNT) && defined(HAWK_ATOMIC_FETCH_ADD)
+
+#define hawk_rtx_refupval_nocheck_inline(rtx, val) do { \
+	HAWK_ATOMIC_FETCH_ADD(&(val)->v_refs, 1, HAWK_ATOMIC_RELAXED); \
+} while(0)
+
 #define hawk_rtx_refupval_inline(rtx, val) do { \
 	if (HAWK_VTR_IS_POINTER(val) && !HAWK_IS_STATICVAL(val)) { \
 		HAWK_ATOMIC_FETCH_ADD(&(val)->v_refs, 1, HAWK_ATOMIC_RELAXED); \
 	} \
 } while(0)
+
 #else
+#define hawk_rtx_refupval_nocheck_inline(rtx, val) do { (val)->v_refs++; } while(0)
+
 #define hawk_rtx_refupval_inline(rtx, val) do { \
 	if (HAWK_VTR_IS_POINTER(val) && !HAWK_IS_STATICVAL(val)) (val)->v_refs++; \
 } while(0)

lib/val.c

@@ -1572,21 +1572,11 @@ hawk_val_t* hawk_rtx_makebobval (hawk_rtx_t* rtx, const void* ptr, hawk_oow_t le
 	return (hawk_val_t*)val;
 }
 
-int hawk_rtx_isstaticval (hawk_rtx_t* rtx, const hawk_val_t* val)
+int HAWK_INLINE hawk_rtx_isstaticval (hawk_rtx_t* rtx, const hawk_val_t* val)
 {
 	return HAWK_VTR_IS_POINTER(val) && HAWK_IS_STATICVAL(val);
 }
 
-int hawk_rtx_isimmval (hawk_rtx_t* rtx, const hawk_val_t* val)
-{
-	return !HAWK_VTR_IS_POINTER(val);
-}
-
-int hawk_rtx_isimmorstaticval (hawk_rtx_t* rtx, const hawk_val_t* val)
-{
-	return !HAWK_VTR_IS_POINTER(val) || HAWK_IS_STATICVAL(val);
-}
-
 int hawk_rtx_getvaltype (hawk_rtx_t* rtx, const hawk_val_t* val)
 {
 	return HAWK_RTX_GETVALTYPE(rtx, val);