Charles G. Waldman <cgw@fnal.gov>:
Add the EXTENDED_ARG opcode to the virtual machine, allowing 32-bit
arguments to opcodes instead of being forced to stick to the 16-bit
limit. This is especially useful for machine-generated code, which
can be too long for the SET_LINENO parameter to fit into 16 bits.
This closes the implementation portion of SourceForge patch #100893.
diff --git a/Include/node.h b/Include/node.h
index affa8cd..96eb350 100644
--- a/Include/node.h
+++ b/Include/node.h
@@ -19,8 +19,8 @@
typedef struct _node {
short n_type;
char *n_str;
- short n_lineno;
- short n_nchildren;
+ int n_lineno;
+ int n_nchildren;
struct _node *n_child;
} node;
diff --git a/Include/opcode.h b/Include/opcode.h
index a7b642a..f900aa9 100644
--- a/Include/opcode.h
+++ b/Include/opcode.h
@@ -130,6 +130,9 @@
#define CALL_FUNCTION_KW 141 /* #args + (#kwargs<<8) */
#define CALL_FUNCTION_VAR_KW 142 /* #args + (#kwargs<<8) */
+/* Support for opargs more than 16 bits long */
+#define EXTENDED_ARG 143
+
/* Comparison operator codes (argument to COMPARE_OP) */
enum cmp_op {LT, LE, EQ, NE, GT, GE, IN, NOT_IN, IS, IS_NOT, EXC_MATCH, BAD};
diff --git a/Lib/dis.py b/Lib/dis.py
index 3a80e74..9fc9d30 100644
--- a/Lib/dis.py
+++ b/Lib/dis.py
@@ -56,6 +56,7 @@
labels = findlabels(code)
n = len(code)
i = 0
+ extended_arg = 0
while i < n:
c = code[i]
op = ord(c)
@@ -68,8 +69,11 @@
print string.ljust(opname[op], 20),
i = i+1
if op >= HAVE_ARGUMENT:
- oparg = ord(code[i]) + ord(code[i+1])*256
+ oparg = ord(code[i]) + ord(code[i+1])*256 + extended_arg
+ extended_arg = 0
i = i+2
+ if op == EXTENDED_ARG:
+ extended_arg = oparg*65536L
print string.rjust(`oparg`, 5),
if op in hasconst:
print '(' + `co.co_consts[oparg]` + ')',
@@ -258,6 +262,8 @@
def_op('CALL_FUNCTION_KW', 141) # #args + (#kwargs << 8)
def_op('CALL_FUNCTION_VAR_KW', 142) # #args + (#kwargs << 8)
+def_op('EXTENDED_ARG', 143)
+EXTENDED_ARG = 143
def _test():
"""Simple test program to disassemble a file."""
diff --git a/Parser/node.c b/Parser/node.c
index 910192d..6844965 100644
--- a/Parser/node.c
+++ b/Parser/node.c
@@ -8,7 +8,12 @@
redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
******************************************************************/
+#ifdef HAVE_LIMITS_H
#include <limits.h>
+#endif
+#ifndef INT_MAX
+#define INT_MAX 2147483647
+#endif
/* Parse tree node implementation */
@@ -39,7 +44,7 @@
register int nch = n1->n_nchildren;
register int nch1 = nch+1;
register node *n;
- if (nch == SHRT_MAX || nch < 0)
+ if (nch == INT_MAX || nch < 0)
return E_OVERFLOW;
if (XXXROUNDUP(nch) < nch1) {
n = n1->n_child;
diff --git a/Python/ceval.c b/Python/ceval.c
index 23c477b..fb7b5bc 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -613,6 +613,7 @@
opcode = NEXTOP();
if (HAS_ARG(opcode))
oparg = NEXTARG();
+ dispatch_opcode:
#ifdef DYNAMIC_EXECUTION_PROFILE
#ifdef DXPAIRS
dxpairs[lastopcode][opcode]++;
@@ -1750,6 +1751,11 @@
if (x != NULL) continue;
break;
+ case EXTENDED_ARG:
+ opcode = NEXTOP();
+ oparg = oparg<<16 | NEXTARG();
+ goto dispatch_opcode;
+ break;
default:
fprintf(stderr,
diff --git a/Python/compile.c b/Python/compile.c
index f239bb6..3b7c87a 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -36,6 +36,9 @@
#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif
+#ifndef INT_MAX
+#define INT_MAX 2147483647
+#endif
/* Three symbols from graminit.h are also defined in Python.h, with
Py_ prefixes to their names. Python.h can't include graminit.h
@@ -572,11 +575,17 @@
static void
com_addoparg(struct compiling *c, int op, int arg)
{
+ int extended_arg = arg >> 16;
if (op == SET_LINENO) {
com_set_lineno(c, arg);
if (Py_OptimizeFlag)
return;
}
+ if (extended_arg){
+ com_addbyte(c, EXTENDED_ARG);
+ com_addint(c, extended_arg);
+ arg &= 0xffff;
+ }
com_addbyte(c, op);
com_addint(c, arg);
}
@@ -606,7 +615,14 @@
prev = code[anchor] + (code[anchor+1] << 8);
dist = target - (anchor+2);
code[anchor] = dist & 0xff;
- code[anchor+1] = dist >> 8;
+ dist >>= 8;
+ code[anchor+1] = dist;
+ dist >>= 8;
+ if (dist) {
+ com_error(c, PyExc_SystemError,
+ "com_backpatch: offset too large");
+ break;
+ }
if (!prev)
break;
anchor -= prev;
@@ -3364,6 +3380,7 @@
break;
if (HAS_ARG(opcode))
oparg = NEXTARG();
+ dispatch_opcode1:
switch (opcode) {
case STORE_NAME:
case DELETE_NAME:
@@ -3374,6 +3391,11 @@
case EXEC_STMT:
c->c_flags &= ~CO_OPTIMIZED;
break;
+ case EXTENDED_ARG:
+ opcode = NEXTOP();
+ oparg = oparg<<16 | NEXTARG();
+ goto dispatch_opcode1;
+ break;
}
}
@@ -3389,6 +3411,7 @@
break;
if (HAS_ARG(opcode))
oparg = NEXTARG();
+ dispatch_opcode2:
if (opcode == LOAD_NAME ||
opcode == STORE_NAME ||
opcode == DELETE_NAME) {
@@ -3403,13 +3426,20 @@
continue;
}
i = PyInt_AsLong(v);
+ if (i >> 16) /* too big for 2 bytes */
+ continue;
switch (opcode) {
case LOAD_NAME: cur_instr[0] = LOAD_FAST; break;
case STORE_NAME: cur_instr[0] = STORE_FAST; break;
case DELETE_NAME: cur_instr[0] = DELETE_FAST; break;
}
cur_instr[1] = i & 0xff;
- cur_instr[2] = (i>>8) & 0xff;
+ cur_instr[2] = i >> 8;
+ }
+ if (opcode == EXTENDED_ARG) {
+ opcode = NEXTOP();
+ oparg = oparg<<16 | NEXTARG();
+ goto dispatch_opcode2;
}
}