Diff: src/vm/codeobj.h

Revision:

0:14e5e829dffe

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/vm/codeobj.h	Wed Jul 21 12:50:41 2010 +0000
@@ -0,0 +1,182 @@
+/*
+# This file is Copyright 2003, 2006, 2007, 2009 Dean Hall.
+#
+# This file is part of the PyMite VM.
+# The PyMite VM is free software: you can redistribute it and/or modify
+# it under the terms of the GNU GENERAL PUBLIC LICENSE Version 2.
+#
+# The PyMite VM is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# A copy of the GNU GENERAL PUBLIC LICENSE Version 2
+# is seen in the file COPYING in this directory.
+*/
+
+
+#ifndef __CODEOBJ_H__
+#define __CODEOBJ_H__
+
+
+/**
+ * \file
+ * \brief CodeObj Type
+ *
+ * CodeObj type header.
+ */
+
+
+/** Code image field offset consts */
+#define CI_TYPE_FIELD       0
+#define CI_SIZE_FIELD       1
+#define CI_ARGCOUNT_FIELD   3
+#define CI_FLAGS_FIELD      4
+#define CI_STACKSIZE_FIELD  5
+#define CI_NLOCALS_FIELD    6
+#ifdef HAVE_CLOSURES
+#define CI_FREEVARS_FIELD   7
+#define CI_NAMES_FIELD      8
+#else
+#define CI_NAMES_FIELD      7
+#endif /* HAVE_CLOSURES */
+
+/** Native code image size */
+#define NATIVE_IMAGE_SIZE   4
+
+/* Masks for co_flags (from Python's code.h) */
+#define CO_OPTIMIZED 0x01
+#define CO_NEWLOCALS 0x02
+#define CO_VARARGS 0x04
+#define CO_VARKEYWORDS 0x08
+#define CO_NESTED 0x10
+#define CO_GENERATOR 0x20
+#define CO_NOFREE 0x40
+
+/**
+ * Code Object
+ *
+ * An extended object that holds only the most frequently used parts
+ * of the static code image.  Other parts can be obtained by
+ * inspecting the code image itself.
+ */
+typedef struct PmCo_s
+{
+    /** object descriptor */
+    PmObjDesc_t od;
+    /** memory space selector */
+    PmMemSpace_t co_memspace:8;
+    /** address in progmem of the code image, or of code img obj in heap */
+    uint8_t const *co_codeimgaddr;
+    /** address in RAM of names tuple */
+    pPmTuple_t co_names;
+    /** address in RAM of constants tuple */
+    pPmTuple_t co_consts;
+#ifdef HAVE_CLOSURES
+    /** Number of freevars */
+    uint8_t co_nfreevars;
+    /** address in RAM of cellvars tuple */
+    pPmTuple_t co_cellvars;
+    /** Number of local variables */
+    uint16_t co_nlocals;
+#endif /* HAVE_CLOSURES */
+    /** address in memspace of bytecode (or native function) */
+    uint8_t const *co_codeaddr;
+    /** number of positional arguments the function expects */
+    uint8_t co_argcount;
+    /** compiler flags */
+    uint8_t co_flags;
+} PmCo_t,
+ *pPmCo_t;
+
+/**
+ * Native Code Object
+ *
+ * An extended object that holds only the most frequently used parts
+ * of the static native image.  Other parts can be obtained by
+ * inspecting the native image itself.
+ */
+typedef struct PmNo_s
+{
+    /** object descriptor */
+    PmObjDesc_t od;
+    /** expected num args to the func */
+    int8_t no_argcount;
+    /** index into native function table */
+    int16_t no_funcindx;
+} PmNo_t,
+ *pPmNo_t;
+
+
+/**
+ * Creates a CodeObj by loading info from a code image in memory.
+ *
+ * An image is a static representation of a Python object.
+ * The process of converting an object to and from an image
+ * is also called marshalling.
+ * In PyMite, code images are the equivalent of .pyc files.
+ * Code images can only contain a select subset of object types
+ * (None, Int, Float, String, Slice?, Tuple, and CodeImg).
+ * All other types (Lists, Dicts, CodeObjs, Modules, Classes,
+ * Functions, ClassInstances) are built at runtime.
+ *
+ * All multibyte values are in Little Endian order
+ * (least significant byte comes first in the byte stream).
+ *
+ * memspace and *paddr determine the start of the code image.
+ * Load the code object with values from the code image,
+ * including the names and consts tuples.
+ * Leave contents of paddr pointing one byte past end of
+ * code img.
+ *
+ * The code image has the following structure:
+ *      -type:      8b - OBJ_TYPE_CIM
+ *      -size:      16b - number of bytes
+ *                  the code image occupies.
+ *      -argcount:  8b - number of arguments to this code obj.
+ *      -stacksz:   8b - the maximum arg-stack size needed.
+ *      -nlocals:   8b - number of local vars in the code obj.
+ *      -names:     Tuple - tuple of string objs.
+ *      -consts:    Tuple - tuple of objs.
+ *      -code:      8b[] - bytecode array.
+ *
+ * @param   memspace memory space containing image
+ * @param   paddr ptr to ptr to code img in memspace
+ *          return by reference: paddr points one byte
+ *          past end of code img
+ * @param   r_pco Return arg.  New code object with fields
+ *          filled in.
+ * @return  Return status
+ */
+PmReturn_t
+co_loadFromImg(PmMemSpace_t memspace, uint8_t const **paddr, pPmObj_t *r_pco);
+
+/**
+ * Creates a Native code object by loading a native image.
+ *
+ * An image is a static representation of a Python object.
+ * A native image is much smaller than a regular image
+ * because only two items of data are needed after the type:
+ * the number of args the func expects and the index into
+ * the native function table.
+ * A reference to the image is not needed since it is
+ * just as efficient to store the info in RAM as it is to
+ * store a pointer and memspace value.
+ *
+ * memspace and *paddr determine the start of the native image.
+ * Loads the argcount and the func index from the native object.
+ * Leaves contents of paddr pointing one byte past end of
+ * code img.
+ *
+ * The native image has the following structure:
+ *      -type:      8b - OBJ_TYPE_CIM
+ *      -argcount:  8b - number of arguments to this code obj.
+ *      -code:      16b - index into native function table.
+ *
+ * @param   memspace memory space containing image
+ * @param   paddr ptr to ptr to code img in memspace (return)
+ * @param   r_pno Return by reference, new code object 
+ * @return  Return status
+ */
+PmReturn_t no_loadFromImg(PmMemSpace_t memspace,
+                          uint8_t const **paddr, pPmObj_t *r_pno);
+
+#endif /* __CODEOBJ_H__ */