[Cegcc-devel] [ cegcc-Bugs-2901705 ] broken winmain_ce.c?

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Bugs item #2901705, was opened at 2009-11-21 11:58
Message generated for change (Comment added) made by pedroalves
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Category: MinGW32CE (arm-wince-mingw32ce
Group: None
Status: Open
>Resolution: Accepted
Priority: 5
Private: No
Submitted By: Ivan Maidanski (ivmai)
Assigned to: Nobody/Anonymous (nobody)
Summary: broken winmain_ce.c?

Initial Comment:
It seems that __mainArgs() in winmain_ce.c produces a bad entry in __argv[] when a single argument is passed to the program.
See the test case (which crashes if one arg is passed to it) - to run it on my arm box I've created "a.lnk" file containing: 255#"\SDMMC\Temp\a.exe" x

PS. At present, to workaround the bug, I use a third-party WinMain() wrapper for main().

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>Comment By: Pedro Alves (pedroalves)
Date: 2009-12-10 11:17

Message:
On the other hand, these points:
" — argv[argc] shall be a null pointer.
— If the value of argc is greater than zero, the array members argv[0]
through
argv[argc-1] inclusive shall contain pointers to strings, which are
given
implementation-defined values by the host environment prior to
program startup"

may mean your test is defined after all.  Hmm.  I'll take a new look at
this then.


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Comment By: Pedro Alves (pedroalves)
Date: 2009-12-10 11:13

Message:
>> Your test is borked. You should be iterating from 0 to argc.
>You just suggest this to workaround the bug, right? 

No, I'm saying that your test is no C.  It is broken.  It is doing
undefined things.

> Or, could you refer to
>a standard prohibiting comparing argv[i] against NULL?

See the C standard, "5.1.2.2.1 Program startup".  You're making up that
guarantee.  Only argv[0].. argv[argc-1] are defined.

"1 The function called at program startup is named main. The
implementation declares no
  prototype for this function. It shall be defined with a return type of
int and with no
  parameters:
          int main(void) { /* ... */ }
  or with two parameters (referred to here as argc and argv, though any
names may be
  used, as they are local to the function in which they are declared):
          int main(int argc, char *argv[]) { /* ... */ }
  or equivalent;9) or in some other implementation-defined manner.
2 If they are declared, the parameters to the main function shall obey the
following
  constraints:
  — The value of argc shall be nonnegative.
  — argv[argc] shall be a null pointer.
  — If the value of argc is greater than zero, the array members argv[0]
through
      argv[argc-1] inclusive shall contain pointers to strings, which are
given
      implementation-defined values by the host environment prior to
program startup. The
      intent is to supply to the program information determined prior to
program startup
      from elsewhere in the hosted environment. If the host environment is
not capable of
      supplying strings with letters in both uppercase and lowercase, the
implementation
      shall ensure that the strings are received in lowercase.
  — If the value of argc is greater than zero, the string pointed to by
argv[0]
      represents the program name; argv[0][0] shall be the null character
if the
      program name is not available from the host environment. If the
value of argc is
      greater than one, the strings pointed to by argv[1] through
argv[argc-1]
      represent the program parameters.
  — The parameters argc and argv and the strings pointed to by the argv
array shall
      be modifiable by the program, and retain their last-stored values
between program
      startup and program termination.
"

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Comment By: Ivan Maidanski (ivmai)
Date: 2009-12-10 11:01

Message:
> Your test is borked. You should be iterating from 0 to argc.
You just suggest this to workaround the bug, right? Or, could you refer to
a standard prohibiting comparing argv[i] against NULL?

----------------------------------------------------------------------

Comment By: Pedro Alves (pedroalves)
Date: 2009-12-10 10:40

Message:
Your test is borked.  You should be iterating from 0 to argc.

- for (i = 0; argv[i]; i++)
+ for (i = 0; i < argc; i++)
  printf("%s\n", argv[i]);
 return 0;


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