* Re: [Emacs-diffs] master 0c94b84: * nt/inc/ms-w32.h (execve) [MINGW_W64]: Make commentary more accurate. [not found] ` <20160901171604.8DF4D22016A@vcs.savannah.gnu.org> @ 2016-09-01 19:57 ` Ken Brown 2016-09-02 6:53 ` Eli Zaretskii 0 siblings, 1 reply; 6+ messages in thread From: Ken Brown @ 2016-09-01 19:57 UTC (permalink / raw) To: emacs-devel, Eli Zaretskii; +Cc: Angelo Graziosi On 9/1/2016 1:16 PM, Eli Zaretskii wrote: > + However, using the prototype with intptr_t causes GCC to emit > + warnings. Fortunately, execve is not used in the MinGW build, but > + the code that references it is still compiled. */ Wouldn't it be easier to prevent that code from being compiled? Then you could just remove the prototype. It seems confusing to include a prototype and several lines of commentary for a function that's not used. I think the following would suffice: --- a/src/sysdep.c +++ b/src/sysdep.c @@ -146,6 +146,7 @@ disable_address_randomization (void) } #endif +#ifndef WINDOWSNT /* Execute the program in FILE, with argument vector ARGV and environ ENVP. Return an error number if unsuccessful. This is like execve except it reenables ASLR in the executed program if necessary, and @@ -170,6 +171,7 @@ emacs_exec_file (char const *file, char *const *argv, char *const *envp) return err; } +#endif /* not WINDOWSNT */ /* If FD is not already open, arrange for it to be open with FLAGS. */ static void Ken ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Emacs-diffs] master 0c94b84: * nt/inc/ms-w32.h (execve) [MINGW_W64]: Make commentary more accurate. 2016-09-01 19:57 ` [Emacs-diffs] master 0c94b84: * nt/inc/ms-w32.h (execve) [MINGW_W64]: Make commentary more accurate Ken Brown @ 2016-09-02 6:53 ` Eli Zaretskii 2016-09-04 10:34 ` Angelo Graziosi 0 siblings, 1 reply; 6+ messages in thread From: Eli Zaretskii @ 2016-09-02 6:53 UTC (permalink / raw) To: Ken Brown, Paul Eggert; +Cc: angelo.graziosi, emacs-devel > From: Ken Brown <kbrown@cornell.edu> > Cc: Angelo Graziosi <angelo.graziosi@alice.it> > Date: Thu, 1 Sep 2016 15:57:00 -0400 > > On 9/1/2016 1:16 PM, Eli Zaretskii wrote: > > + However, using the prototype with intptr_t causes GCC to emit > > + warnings. Fortunately, execve is not used in the MinGW build, but > > + the code that references it is still compiled. */ > > Wouldn't it be easier to prevent that code from being compiled? It would for the Windows build, but it would add one (actually more, see below) #ifdef WINDOWSNT into the mainline code. AFAIR, Paul (CC'ed) wanted to keep those to a minimum, so I preferred not to ifdef away the code. > I think the following would suffice: > > --- a/src/sysdep.c > +++ b/src/sysdep.c > @@ -146,6 +146,7 @@ disable_address_randomization (void) > } > #endif > > +#ifndef WINDOWSNT > /* Execute the program in FILE, with argument vector ARGV and environ > ENVP. Return an error number if unsuccessful. This is like execve > except it reenables ASLR in the executed program if necessary, and > @@ -170,6 +171,7 @@ emacs_exec_file (char const *file, char *const > *argv, char *const *envp) > > return err; > } > +#endif /* not WINDOWSNT */ That whole function is not used on Windows, so if we are to do this, the following fragment of main in emacs.c should also be ifdefed away: /* True if address randomization interferes with memory allocation. */ # ifdef __PPC64__ bool disable_aslr = true; # else bool disable_aslr = dumping; # endif if (disable_aslr && disable_address_randomization ()) { /* Set this so the personality will be reverted before execs after this one. */ xputenv ("EMACS_HEAP_EXEC=true"); /* Address randomization was enabled, but is now disabled. Re-execute Emacs to get a clean slate. */ execvp (argv[0], argv); /* If the exec fails, warn and then try anyway. */ perror (argv[0]); } If Paul doesn't mind (nor anyone else), we can certainly do that. Thanks. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Emacs-diffs] master 0c94b84: * nt/inc/ms-w32.h (execve) [MINGW_W64]: Make commentary more accurate. 2016-09-02 6:53 ` Eli Zaretskii @ 2016-09-04 10:34 ` Angelo Graziosi 2016-09-04 18:47 ` Paul Eggert 0 siblings, 1 reply; 6+ messages in thread From: Angelo Graziosi @ 2016-09-04 10:34 UTC (permalink / raw) To: Eli Zaretskii, Ken Brown, Paul Eggert; +Cc: emacs-devel Hi Paul, Il 02/09/2016 08:53, Eli Zaretskii ha scritto: >> From: Ken Brown <kbrown@cornell.edu> >> Cc: Angelo Graziosi <angelo.graziosi@alice.it> >> Date: Thu, 1 Sep 2016 15:57:00 -0400 >> >> On 9/1/2016 1:16 PM, Eli Zaretskii wrote: >>> + However, using the prototype with intptr_t causes GCC to emit >>> + warnings. Fortunately, execve is not used in the MinGW build, but >>> + the code that references it is still compiled. */ >> >> Wouldn't it be easier to prevent that code from being compiled? > > It would for the Windows build, but it would add one (actually more, > see below) #ifdef WINDOWSNT into the mainline code. AFAIR, Paul > (CC'ed) wanted to keep those to a minimum, so I preferred not to ifdef > away the code. if I understand (in short) there is code compiled but not used.. Would it better to exclude that code as Ken suggests, then? May you comment? Thanks, Angelo. > >> I think the following would suffice: >> >> --- a/src/sysdep.c >> +++ b/src/sysdep.c >> @@ -146,6 +146,7 @@ disable_address_randomization (void) >> } >> #endif >> >> +#ifndef WINDOWSNT >> /* Execute the program in FILE, with argument vector ARGV and environ >> ENVP. Return an error number if unsuccessful. This is like execve >> except it reenables ASLR in the executed program if necessary, and >> @@ -170,6 +171,7 @@ emacs_exec_file (char const *file, char *const >> *argv, char *const *envp) >> >> return err; >> } >> +#endif /* not WINDOWSNT */ > > That whole function is not used on Windows, so if we are to do this, > the following fragment of main in emacs.c should also be ifdefed away: > > /* True if address randomization interferes with memory allocation. */ > # ifdef __PPC64__ > bool disable_aslr = true; > # else > bool disable_aslr = dumping; > # endif > > if (disable_aslr && disable_address_randomization ()) > { > /* Set this so the personality will be reverted before execs > after this one. */ > xputenv ("EMACS_HEAP_EXEC=true"); > > /* Address randomization was enabled, but is now disabled. > Re-execute Emacs to get a clean slate. */ > execvp (argv[0], argv); > > /* If the exec fails, warn and then try anyway. */ > perror (argv[0]); > } > > If Paul doesn't mind (nor anyone else), we can certainly do that. > > Thanks. > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Emacs-diffs] master 0c94b84: * nt/inc/ms-w32.h (execve) [MINGW_W64]: Make commentary more accurate. 2016-09-04 10:34 ` Angelo Graziosi @ 2016-09-04 18:47 ` Paul Eggert 2016-09-04 19:00 ` Eli Zaretskii 2016-09-04 20:58 ` Angelo Graziosi 0 siblings, 2 replies; 6+ messages in thread From: Paul Eggert @ 2016-09-04 18:47 UTC (permalink / raw) To: Angelo Graziosi, Eli Zaretskii, Ken Brown; +Cc: emacs-devel I'd rather keep the mainline code as free from such ifdefs as possible. If the problem is that GCC complains about execvp due to some configuration problem on MS-Windows, perhaps you could put a wrapper into w32common.h or some similar location, to pacify the compiler. emacsclient.c already uses such a wrapper, for another reason. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Emacs-diffs] master 0c94b84: * nt/inc/ms-w32.h (execve) [MINGW_W64]: Make commentary more accurate. 2016-09-04 18:47 ` Paul Eggert @ 2016-09-04 19:00 ` Eli Zaretskii 2016-09-04 20:58 ` Angelo Graziosi 1 sibling, 0 replies; 6+ messages in thread From: Eli Zaretskii @ 2016-09-04 19:00 UTC (permalink / raw) To: Paul Eggert; +Cc: emacs-devel, kbrown, angelo.graziosi > From: Paul Eggert <eggert@cs.ucla.edu> > Date: Sun, 4 Sep 2016 11:47:16 -0700 > Cc: emacs-devel@gnu.org > > If the problem is that GCC complains about execvp due to some configuration > problem on MS-Windows, perhaps you could put a wrapper into w32common.h or some > similar location, to pacify the compiler. emacsclient.c already uses such a > wrapper, for another reason. The problem is already solved, so I see no need for a wrapper. Thanks. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Emacs-diffs] master 0c94b84: * nt/inc/ms-w32.h (execve) [MINGW_W64]: Make commentary more accurate. 2016-09-04 18:47 ` Paul Eggert 2016-09-04 19:00 ` Eli Zaretskii @ 2016-09-04 20:58 ` Angelo Graziosi 1 sibling, 0 replies; 6+ messages in thread From: Angelo Graziosi @ 2016-09-04 20:58 UTC (permalink / raw) To: Paul Eggert, Eli Zaretskii, Ken Brown; +Cc: emacs-devel Il 04/09/2016 20:47, Paul Eggert ha scritto: > I'd rather keep the mainline code as free from such ifdefs as possible. > > If the problem is that GCC complains about execvp due to some > configuration problem on MS-Windows, perhaps you could put a wrapper > into w32common.h or some similar location, to pacify the compiler. > emacsclient.c already uses such a wrapper, for another reason. It would be better to continue to have all those warnings! I still think that Ken's solution is the most elegant. In any case, Eli's patch is better than this proposal... Angelo ^ permalink raw reply [flat|nested] 6+ messages in thread
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[not found] ` <20160901171604.8DF4D22016A@vcs.savannah.gnu.org>
2016-09-01 19:57 ` [Emacs-diffs] master 0c94b84: * nt/inc/ms-w32.h (execve) [MINGW_W64]: Make commentary more accurate Ken Brown
2016-09-02 6:53 ` Eli Zaretskii
2016-09-04 10:34 ` Angelo Graziosi
2016-09-04 18:47 ` Paul Eggert
2016-09-04 19:00 ` Eli Zaretskii
2016-09-04 20:58 ` Angelo Graziosi
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