Add warning mode for classic division, almost exactly as specified in
PEP 238. Changes:
- add a new flag variable Py_DivisionWarningFlag, declared in
pydebug.h, defined in object.c, set in main.c, and used in
{int,long,float,complex}object.c. When this flag is set, the
classic division operator issues a DeprecationWarning message.
- add a new API PyRun_SimpleStringFlags() to match
PyRun_SimpleString(). The main() function calls this so that
commands run with -c can also benefit from -Dnew.
- While I was at it, I changed the usage message in main() somewhat:
alphabetized the options, split it in *four* parts to fit in under
512 bytes (not that I still believe this is necessary -- doc strings
elsewhere are much longer), and perhaps most visibly, don't display
the full list of options on each command line error. Instead, the
full list is only displayed when -h is used, and otherwise a brief
reminder of -h is displayed. When -h is used, write to stdout so
that you can do `python -h | more'.
Notes:
- I don't want to use the -W option to control whether the classic
division warning is issued or not, because the machinery to decide
whether to display the warning or not is very expensive (it involves
calling into the warnings.py module). You can use -Werror to turn
the warnings into exceptions though.
- The -Dnew option doesn't select future division for all of the
program -- only for the __main__ module. I don't know if I'll ever
change this -- it would require changes to the .pyc file magic
number to do it right, and a more global notion of compiler flags.
- You can usefully combine -Dwarn and -Dnew: this gives the __main__
module new division, and warns about classic division everywhere
else.
diff --git a/Modules/main.c b/Modules/main.c
index ad2616d..7c368c7 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -2,6 +2,7 @@
#include "Python.h"
#include "osdefs.h"
+#include "compile.h" /* For CO_FUTURE_DIVISION */
#ifdef HAVE_UNISTD_H
#include <unistd.h>
@@ -28,7 +29,7 @@
static int orig_argc;
/* command line options */
-#define BASE_OPTS "c:diOSEtuUvxXhVW:"
+#define BASE_OPTS "c:dD:EhiOStuUvVWxX:"
#ifndef RISCOS
#define PROGRAM_OPTS BASE_OPTS
@@ -45,30 +46,33 @@
"usage: %s [option] ... [-c cmd | file | -] [arg] ...\n";
/* Long usage message, split into parts < 512 bytes */
-static char *usage_top = "\
+static char *usage_1 = "\
Options and arguments (and corresponding environment variables):\n\
+-c cmd : program passed in as string (terminates option list)\n\
-d : debug output from parser (also PYTHONDEBUG=x)\n\
+-D arg : division options: -Dold (default), -Dwarn, -Dnew\n\
+-E : ignore environment variables (such as PYTHONPATH)\n\
+-h : print this help message and exit\n\
+";
+static char *usage_2 = "\
-i : inspect interactively after running script, (also PYTHONINSPECT=x)\n\
and force prompts, even if stdin does not appear to be a terminal\n\
-O : optimize generated bytecode (a tad; also PYTHONOPTIMIZE=x)\n\
-OO : remove doc-strings in addition to the -O optimizations\n\
-S : don't imply 'import site' on initialization\n\
--E : ignore environment variables (such as PYTHONPATH)\n\
-t : issue warnings about inconsistent tab usage (-tt: issue errors)\n\
-";
-static char *usage_mid = "\
-u : unbuffered binary stdout and stderr (also PYTHONUNBUFFERED=x)\n\
+";
+static char *usage_3 = "\
-U : Unicode literals: treats '...' literals like u'...'\n\
-v : verbose (trace import statements) (also PYTHONVERBOSE=x)\n\
--x : skip first line of source, allowing use of non-Unix forms of #!cmd\n\
--h : print this help message and exit\n\
-V : print the Python version number and exit\n\
-W arg : warning control (arg is action:message:category:module:lineno)\n\
--c cmd : program passed in as string (terminates option list)\n\
+-x : skip first line of source, allowing use of non-Unix forms of #!cmd\n\
file : program read from script file\n\
- : program read from stdin (default; interactive mode if a tty)\n\
";
-static char *usage_bot = "\
+static char *usage_4 = "\
arg ...: arguments passed to program in sys.argv[1:]\n\
Other environment variables:\n\
PYTHONSTARTUP: file executed on interactive startup (no default)\n\
@@ -83,10 +87,17 @@
static void
usage(int exitcode, char* program)
{
- fprintf(stderr, usage_line, program);
- fprintf(stderr, usage_top);
- fprintf(stderr, usage_mid);
- fprintf(stderr, usage_bot, DELIM, DELIM, PYTHONHOMEHELP);
+ FILE *f = exitcode ? stderr : stdout;
+
+ fprintf(f, usage_line, program);
+ if (exitcode)
+ fprintf(f, "Try `python -h' for more information.\n");
+ else {
+ fprintf(f, usage_1);
+ fprintf(f, usage_2);
+ fprintf(f, usage_3);
+ fprintf(f, usage_4, DELIM, DELIM, PYTHONHOMEHELP);
+ }
exit(exitcode);
/*NOTREACHED*/
}
@@ -113,6 +124,8 @@
int saw_unbuffered_flag = 0;
PyCompilerFlags cf;
+ cf.cf_flags = 0;
+
orig_argc = argc; /* For Py_GetArgcArgv() */
orig_argv = argv;
@@ -135,13 +148,33 @@
strcat(command, "\n");
break;
}
-
+
switch (c) {
case 'd':
Py_DebugFlag++;
break;
+ case 'D':
+ if (strcmp(_PyOS_optarg, "old") == 0) {
+ Py_DivisionWarningFlag = 0;
+ break;
+ }
+ if (strcmp(_PyOS_optarg, "warn") == 0) {
+ Py_DivisionWarningFlag++;
+ break;
+ }
+ if (strcmp(_PyOS_optarg, "new") == 0) {
+ /* XXX This only affects __main__ */
+ cf.cf_flags |= CO_FUTURE_DIVISION;
+ break;
+ }
+ fprintf(stderr,
+ "-D option should be "
+ "`-Dold', `-Dwarn' or `-Dnew' only\n");
+ usage(2, argv[0]);
+ /* NOTREACHED */
+
case 'i':
inspect++;
saw_inspect_flag = 1;
@@ -290,8 +323,7 @@
(command == NULL && filename == NULL && stdin_is_interactive))
fprintf(stderr, "Python %s on %s\n%s\n",
Py_GetVersion(), Py_GetPlatform(), COPYRIGHT);
-
-
+
if (command != NULL) {
/* Backup _PyOS_optind and force sys.argv[0] = '-c' */
_PyOS_optind--;
@@ -310,10 +342,8 @@
Py_DECREF(v);
}
- cf.cf_flags = 0;
-
if (command) {
- sts = PyRun_SimpleString(command) != 0;
+ sts = PyRun_SimpleStringFlags(command, &cf) != 0;
free(command);
}
else {