Re: [Tinycc-devel] '__builtin_frame_address' warning about suspicious use of this call
Ok I fixed it taking care of gcc version.
http://repo.or.cz/tinycc.git/commitdiff/ed99f3608df3d6dd4c8c7d52d608a8212203
dfe4
Looks good now on Fedora 25.
C.
-Original Message-
From: Tinycc-devel [mailto:tinycc-devel-bounces+eligis=orange...@nongnu.org]
On Behalf Of grischka
Sent: mardi 29 novembre 2016 12:20
To: tinycc-devel@nongnu.org
Subject: Re: [Tinycc-devel] '__builtin_frame_address' warning about
suspicious use of this call
Christian Jullien wrote:
> GCC documentation says:
> Calling this function with a nonzero argument can have unpredictable
> effects, including crashing the calling program. As a result, calls
> that are considered unsafe are diagnosed when the -Wframe-address
> option is in effect. Such calls should only be made in debugging
situations.
>
> ^ This latest sentence makes me afraid!
Actually we are in a "debugging situation" with bcheck.c which is helper
code for the tcc -b switch.
Also, in our case the result is not unpredictable because these functions
are used in a controlled way by calls inserted by the compiler (tcc).
If you use
#pragma GCC diagnostic ignored "-Wframe-address"
it will probably just trigger another warning
xxx.c:00: warning: ignoring #pragma GCC diagnostic with most versions
of gcc.
Alternatively we could just use tcc to compile the library which you get by
commenting out the lines
XCC = $(CC)
near the top of lib/Makefile for i386/x86_84.
Feel free to make such change to mob, if it works.
Thanks,
--- grischka
> Two questions here:
>
> Q1. Should we really call this function with one arg?
>
>
>
> Q2. If safe, we should make this change to avoid this warning:
>
>
>
> diff --git a/lib/bcheck.c b/lib/bcheck.c
>
> index 756c539..8a75654 100644
>
> --- a/lib/bcheck.c
>
> +++ b/lib/bcheck.c
>
> @@ -240,6 +240,9 @@ BOUND_PTR_INDIR(16)
>
> fp = (size_t)__builtin_frame_address(1);\
>
> }
>
> +#pragma GCC diagnostic push
>
> +#pragma GCC diagnostic ignored "-Wframe-address"
>
> +
>
> /* called when entering a function to add all the local regions */
>
> void FASTCALL __bound_local_new(void *p1)
>
> {
>
> @@ -273,6 +276,7 @@ void FASTCALL __bound_local_delete(void *p1)
>
> __bound_delete_region((void *)addr);
>
> }
>
> }
>
> +#pragma GCC diagnostic pop
>
> static BoundEntry *__bound_new_page(void)
>
> {
>
>
>
>
> --
> --
>
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Re: [Tinycc-devel] sleep() interprets argument as milliseconds instead of seconds
From: Tinycc-devel [mailto:tinycc-devel-bounces+nuke48386=yahoo@nongnu.org]
On Behalf Of Hernán J. González
Sent: Tuesday, November 29, 2016 2:53 PM
To: tinycc-devel@nongnu.org
Subject: [Tinycc-devel] sleep() interprets argument as milliseconds instead of
seconds
The POSIX sleep() function ( ) should interpret is input argument as
seconds.
TinyC seems to interpret it as milliseconds.
Using tcc version 0.9.26
/***/
#include
#include
int main() {
int i;
fputs("Looping ...\n",stdout);
for(i=0;i<10;i++) {
fputs(".",stdout);
fflush(stdout);
sleep(3); // seconds?
}
return 0;
}
/***/
Expected behaviour: This should print a dot at 3 seconds interval, the loop
should take 30 seconds.
Result: The 10 dots are printed and the loop ends almost instanteously.
Expected behaviour is attained when replacing '3' by '3000'
I cannot reproduce, tinycc 0.9.26, Debian 8 ‘Jessie’,
Linux sgmtech8 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u2 (2016-10-19)
x86_64 GNU/Linux,
no ‘configure’ flags at all, just ./configure ; make; sudo make install
My simple test was just:
sl.c
---code---
#include
#include
int main(int argc, char **argv) {
sleep(3);
return 0;
}
--- end code---
$time ./sl
real0m3.001s
user0m0.000s
sys 0m0.000s
Maybe it’s distro-related?
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[Tinycc-devel] sleep() interprets argument as milliseconds instead of seconds
The POSIX sleep() function ( ) should interpret is input
argument as seconds.
TinyC seems to interpret it as milliseconds.
Using tcc version 0.9.26
/***/
#include
#include
int main() {
int i;
fputs("Looping ...\n",stdout);
for(i=0;i<10;i++) {
fputs(".",stdout);
fflush(stdout);
sleep(3); // seconds?
}
return 0;
}
/***/
Expected behaviour: This should print a dot at 3 seconds interval, the loop
should take 30 seconds.
Result: The 10 dots are printed and the loop ends almost instanteously.
Expected behaviour is attained when replacing '3' by '3000'
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Re: [Tinycc-devel] '__builtin_frame_address' warning about suspicious use of this call
Christian Jullien wrote:
GCC documentation says:
Calling this function with a nonzero argument can have unpredictable
effects, including crashing the calling program. As a result, calls that are
considered unsafe are diagnosed when the -Wframe-address option is in
effect. Such calls should only be made in debugging situations.
^ This latest sentence makes me afraid!
Actually we are in a "debugging situation" with bcheck.c which
is helper code for the tcc -b switch.
Also, in our case the result is not unpredictable because these
functions are used in a controlled way by calls inserted by the
compiler (tcc).
If you use
#pragma GCC diagnostic ignored "-Wframe-address"
it will probably just trigger another warning
xxx.c:00: warning: ignoring #pragma GCC diagnostic
with most versions of gcc.
Alternatively we could just use tcc to compile the library
which you get by commenting out the lines
XCC = $(CC)
near the top of lib/Makefile for i386/x86_84.
Feel free to make such change to mob, if it works.
Thanks,
--- grischka
Two questions here:
Q1. Should we really call this function with one arg?
Q2. If safe, we should make this change to avoid this warning:
diff --git a/lib/bcheck.c b/lib/bcheck.c
index 756c539..8a75654 100644
--- a/lib/bcheck.c
+++ b/lib/bcheck.c
@@ -240,6 +240,9 @@ BOUND_PTR_INDIR(16)
fp = (size_t)__builtin_frame_address(1);\
}
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wframe-address"
+
/* called when entering a function to add all the local regions */
void FASTCALL __bound_local_new(void *p1)
{
@@ -273,6 +276,7 @@ void FASTCALL __bound_local_delete(void *p1)
__bound_delete_region((void *)addr);
}
}
+#pragma GCC diagnostic pop
static BoundEntry *__bound_new_page(void)
{
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