Diff: vm/frame.c

Revision:

0:65f1469d6bfb

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vm/frame.c	Sat Mar 02 11:54:20 2013 +0000
@@ -0,0 +1,100 @@
+/*
+# This file is Copyright 2002 Dean Hall.
+# This file is part of the PyMite VM.
+# This file is licensed under the MIT License.
+# See the LICENSE file for details.
+*/
+
+
+#undef __FILE_ID__
+#define __FILE_ID__ 0x03
+
+
+/**
+ * \file
+ * \brief VM Frame
+ *
+ * VM frame operations.
+ */
+
+
+#include "pm.h"
+
+
+PmReturn_t
+frame_new(pPmObj_t pfunc, pPmObj_t *r_pobj)
+{
+    PmReturn_t retval = PM_RET_OK;
+    int16_t fsize = 0;
+    pPmCo_t pco = C_NULL;
+    pPmFrame_t pframe = C_NULL;
+    uint8_t *pchunk;
+
+    /* Get fxn's code obj */
+    pco = ((pPmFunc_t)pfunc)->f_co;
+
+    /* TypeError if passed func's CO is not a true COB */
+    if (OBJ_GET_TYPE(pco) != OBJ_TYPE_COB)
+    {
+        PM_RAISE(retval, PM_RET_EX_TYPE);
+        return retval;
+    }
+
+#ifdef HAVE_GENERATORS
+    /* #207: Initializing a Generator using CALL_FUNC needs extra stack slot */
+    fsize = sizeof(PmFrame_t) + (pco->co_stacksize + pco->co_nlocals + 2) * sizeof(pPmObj_t);
+#elif defined(HAVE_CLASSES)
+    /* #230: Calling a class's __init__() takes two extra spaces on the stack */
+    fsize = sizeof(PmFrame_t) + (pco->co_stacksize + pco->co_nlocals + 1) * sizeof(pPmObj_t);
+#else
+    fsize = sizeof(PmFrame_t) + (pco->co_stacksize + pco->co_nlocals - 1) * sizeof(pPmObj_t);
+#endif /* HAVE_CLASSES */
+
+#ifdef HAVE_CLOSURES
+    /* #256: Add support for closures */
+    fsize = fsize + pco->co_nfreevars
+            + ((pco->co_cellvars == C_NULL) ? 0 : pco->co_cellvars->length);
+#endif /* HAVE_CLOSURES */
+
+    /* Allocate a frame */
+    retval = heap_getChunk(fsize, &pchunk);
+    PM_RETURN_IF_ERROR(retval);
+    pframe = (pPmFrame_t)pchunk;
+
+    /* Set frame fields */
+    OBJ_SET_TYPE(pframe, OBJ_TYPE_FRM);
+    pframe->fo_back = C_NULL;
+    pframe->fo_func = (pPmFunc_t)pfunc;
+    pframe->fo_memspace = pco->co_memspace;
+
+    /* Init instruction pointer and block stack */
+    pframe->fo_ip = pco->co_codeaddr;
+    pframe->fo_blockstack = C_NULL;
+
+    /* Get globals and attrs from the function object */
+    pframe->fo_globals = ((pPmFunc_t)pfunc)->f_globals;
+    pframe->fo_attrs = ((pPmFunc_t)pfunc)->f_attrs;
+
+#ifndef HAVE_CLOSURES
+    /* Empty stack points to one past locals */
+    pframe->fo_sp = &(pframe->fo_locals[pco->co_nlocals]);
+#else
+    /* #256: Add support for closures */
+    pframe->fo_sp = &(pframe->fo_locals[pco->co_nlocals + pco->co_nfreevars
+        + ((pco->co_cellvars == C_NULL) ? 0 : pco->co_cellvars->length)]);
+#endif /* HAVE_CLOSURES */
+
+    /* By default, this is a normal frame, not an import or __init__ one */
+    pframe->fo_isImport = 0;
+#ifdef HAVE_CLASSES
+    pframe->fo_isInit = 0;
+#endif
+
+    /* Clear the stack */
+    sli_memset((unsigned char *)&(pframe->fo_locals), (char const)0,
+               (unsigned int)fsize - sizeof(PmFrame_t));
+
+    /* Return ptr to frame */
+    *r_pobj = (pPmObj_t)pframe;
+    return retval;
+}