Mercurial > cpython-lru_cache-weakref

diff Python/compile.c @ 5041:c497929b2371 legacy-trunk

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Instead of emitting SET_LINENO instructions, generate a line number table which is incorporated in the code object. This way, the runtime overhead to keep track of line numbers is only incurred when an exception has to be reported.
author Guido van Rossum <guido@python.org>
date Fri, 24 Jan 1997 03:43:35 +0000
parents 6840ff89d24a
children bda01a374762
line wrap: on
line diff
--- a/Python/compile.c	Fri Jan 24 03:41:09 1997 +0000
+++ b/Python/compile.c	Fri Jan 24 03:43:35 1997 +0000
@@ -76,6 +76,8 @@
 	{"co_varnames",	T_OBJECT,	OFF(co_varnames),	READONLY},
 	{"co_filename",	T_OBJECT,	OFF(co_filename),	READONLY},
 	{"co_name",	T_OBJECT,	OFF(co_name),		READONLY},
+	{"co_firstlineno", T_INT,	OFF(co_firstlineno),	READONLY},
+	{"co_lnotab",	T_OBJECT,	OFF(co_lnotab),		READONLY},
 	{NULL}	/* Sentinel */
 };
 
@@ -180,7 +182,8 @@
 
 codeobject *
 newcodeobject(argcount, nlocals, stacksize, flags,
-	      code, consts, names, varnames, filename, name)
+	      code, consts, names, varnames, filename, name,
+	      firstlineno, lnotab)
 	int argcount;
 	int nlocals;
 	int stacksize;
@@ -191,6 +194,8 @@
 	object *varnames;
 	object *filename;
 	object *name;
+	int firstlineno;
+	object *lnotab;
 {
 	codeobject *co;
 	int i;
@@ -201,7 +206,8 @@
 	    names == NULL || !is_tupleobject(names) ||
 	    varnames == NULL || !is_tupleobject(varnames) ||
 	    name == NULL || !is_stringobject(name) ||
-	    filename == NULL || !is_stringobject(filename)) {
+	    filename == NULL || !is_stringobject(filename) ||
+		lnotab == NULL || !is_stringobject(lnotab)) {
 		err_badcall();
 		return NULL;
 	}
@@ -252,6 +258,9 @@
 		co->co_filename = filename;
 		INCREF(name);
 		co->co_name = name;
+		co->co_firstlineno = firstlineno;
+		INCREF(lnotab);
+		co->co_lnotab = lnotab;
 	}
 	return co;
 }
@@ -282,6 +291,9 @@
 	int c_lineno;		/* Current line number */
 	int c_stacklevel;	/* Current stack level */
 	int c_maxstacklevel;	/* Maximum stack level */
+	int c_firstlineno;
+	object *c_lnotab;	/* Table mapping address to line number */
+	int c_last_addr, c_last_line, c_lnotab_next;
 #ifdef PRIVATE_NAME_MANGLING
 	char *c_private;	/* for private name mangling */
 #endif
@@ -387,6 +399,8 @@
 		goto fail_00;
 	if ((c->c_varnames = newlistobject(0)) == NULL)
 		goto fail_000;
+	if ((c->c_lnotab = newsizedstringobject((char *)NULL, 1000)) == NULL)
+		goto fail_0000;
 	c->c_nlocals = 0;
 	c->c_argcount = 0;
 	c->c_flags = 0;
@@ -402,8 +416,14 @@
 	c->c_lineno = 0;
 	c->c_stacklevel = 0;
 	c->c_maxstacklevel = 0;
+	c->c_firstlineno = 0;
+	c->c_last_addr = 0;
+	c->c_last_line = 0;
+	c-> c_lnotab_next = 0;
 	return 1;
 	
+  fail_0000:
+  	DECREF(c->c_lnotab);
   fail_000:
   	DECREF(c->c_locals);
   fail_00:
@@ -428,6 +448,7 @@
 	XDECREF(c->c_globals);
 	XDECREF(c->c_locals);
 	XDECREF(c->c_varnames);
+	XDECREF(c->c_lnotab);
 }
 
 static void
@@ -462,6 +483,8 @@
 {
 	if (c->c_code != NULL)
 		resizestring(&c->c_code, c->c_nexti);
+	if (c->c_lnotab != NULL)
+		resizestring(&c->c_lnotab, c->c_lnotab_next);
 }
 
 static void
@@ -500,15 +523,68 @@
 }
 
 static void
+com_add_lnotab(c, addr, line)
+	struct compiling *c;
+	int addr;
+	int line;
+{
+	int size;
+	char *p;
+	if (c->c_lnotab == NULL)
+		return;
+	size = getstringsize(c->c_lnotab);
+	if (c->c_lnotab_next+2 > size) {
+		if (resizestring(&c->c_lnotab, size + 1000) < 0) {
+			c->c_errors++;
+			return;
+		}
+	}
+	p = getstringvalue(c->c_lnotab) + c->c_lnotab_next;
+	*p++ = addr;
+	*p++ = line;
+	c->c_lnotab_next += 2;
+}
+
+static void
+com_set_lineno(c, lineno)
+	struct compiling *c;
+	int lineno;
+{
+	c->c_lineno = lineno;
+	if (c->c_firstlineno == 0) {
+		c->c_firstlineno = c->c_last_line = lineno;
+	}
+	else {
+		int incr_addr = c->c_nexti - c->c_last_addr;
+		int incr_line = lineno - c->c_last_line;
+		while (incr_addr > 0 || incr_line > 0) {
+			int trunc_addr = incr_addr;
+			int trunc_line = incr_line;
+			if (trunc_addr > 255)
+				trunc_addr = 255;
+			if (trunc_line > 255)
+				trunc_line = 255;
+			com_add_lnotab(c, trunc_addr, trunc_line);
+			incr_addr -= trunc_addr;
+			incr_line -= trunc_line;
+		}
+		c->c_last_addr = c->c_nexti;
+		c->c_last_line = lineno;
+	}
+}
+
+static void
 com_addoparg(c, op, arg)
 	struct compiling *c;
 	int op;
 	int arg;
 {
 	if (op == SET_LINENO)
-		c->c_lineno = arg;
-	com_addbyte(c, op);
-	com_addint(c, arg);
+		com_set_lineno(c, arg);
+	else {
+		com_addbyte(c, op);
+		com_addint(c, arg);
+	}
 }
 
 static void
@@ -3212,7 +3288,9 @@
 					   names,
 					   varnames,
 					   filename,
-					   name);
+					   name,
+					   sc.c_firstlineno,
+					   sc.c_lnotab);
 		XDECREF(consts);
 		XDECREF(names);
 		XDECREF(varnames);
@@ -3222,3 +3300,21 @@
 	com_free(&sc);
 	return co;
 }
+
+int
+PyCode_Addr2Line(co, addrq)
+	PyCodeObject *co;
+	int addrq;
+{
+	int size = PyString_Size(co->co_lnotab) / 2;
+	char *p = PyString_AsString(co->co_lnotab);
+	int line = co->co_firstlineno;
+	int addr = 0;
+	while (--size >= 0) {
+		addr += *p++;
+		if (addr > addrq)
+			break;
+		line += *p++;
+	}
+	return line;
+}