| Message ID | 1496828499-30874-1-git-send-email-thuth@redhat.com |
|---|---|
| State | Accepted |
| Headers | show |
On 07/06/17 19:41, Thomas Huth wrote: > puts() does not change the string, so the parameter can be "const". > > Signed-off-by: Thomas Huth <thuth@redhat.com> Thanks, applied. While you are fixing stuff like this, I started getting: /home/aik/p/slof/slof/paflof.c: In function ‘engine’: /home/aik/p/slof/slof/paflof.c:84:23: warning: array subscript is below array bounds [-Warray-bounds] dp = the_data_stack - 1; ~~~~~~~~~~~~~~~^~~ /home/aik/p/slof/slof/paflof.c:85:22: warning: array subscript is below array bounds [-Warray-bounds] rp = handler_stack - 1; ~~~~~~~~~~~~~~^~~ with gcc (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1) from Fedora24/BE. Can you please take a look on this? Thanks. > --- > lib/libc/include/stdio.h | 2 +- > lib/libc/stdio/puts.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/lib/libc/include/stdio.h b/lib/libc/include/stdio.h > index 84cddea..c54528f 100644 > --- a/lib/libc/include/stdio.h > +++ b/lib/libc/include/stdio.h > @@ -51,7 +51,7 @@ int setvbuf(FILE *stream, char *buf, int mode , size_t size); > > int putc(int ch, FILE *stream); > int putchar(int ch); > -int puts(char *str); > +int puts(const char *str); > > int scanf(const char *format, ...) __attribute__((format (scanf, 1, 2))); > int fscanf(FILE *stream, const char *format, ...) __attribute__((format (scanf, 2, 3))); > diff --git a/lib/libc/stdio/puts.c b/lib/libc/stdio/puts.c > index 3f48dbf..9a93008 100644 > --- a/lib/libc/stdio/puts.c > +++ b/lib/libc/stdio/puts.c > @@ -17,7 +17,7 @@ > > > int > -puts(char *str) > +puts(const char *str) > { > int ret; > >
On 08.06.2017 08:12, Alexey Kardashevskiy wrote: [...] > While you are fixing stuff like this, I started getting: > > /home/aik/p/slof/slof/paflof.c: In function ‘engine’: > /home/aik/p/slof/slof/paflof.c:84:23: warning: array subscript is below > array bounds [-Warray-bounds] > dp = the_data_stack - 1; > ~~~~~~~~~~~~~~~^~~ > /home/aik/p/slof/slof/paflof.c:85:22: warning: array subscript is below > array bounds [-Warray-bounds] > rp = handler_stack - 1; > ~~~~~~~~~~~~~~^~~ > > with gcc (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1) from Fedora24/BE. > > Can you please take a look on this? Thanks. See Segher's suggestions here: https://lists.ozlabs.org/pipermail/slof/2016-August/001221.html IMHO we could also just simply sacrifice the first stack entry and only use "dp = the_data_stack", without adding the inline asm here (to keep paflof.c portable). Thomas
On Thu, Jun 08, 2017 at 08:54:06AM +0200, Thomas Huth wrote: > On 08.06.2017 08:12, Alexey Kardashevskiy wrote: > > /home/aik/p/slof/slof/paflof.c: In function ‘engine’: > > /home/aik/p/slof/slof/paflof.c:84:23: warning: array subscript is below > > array bounds [-Warray-bounds] > > dp = the_data_stack - 1; > > ~~~~~~~~~~~~~~~^~~ > > /home/aik/p/slof/slof/paflof.c:85:22: warning: array subscript is below > > array bounds [-Warray-bounds] > > rp = handler_stack - 1; > > ~~~~~~~~~~~~~~^~~ > > > > with gcc (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1) from Fedora24/BE. > > > > Can you please take a look on this? Thanks. > > See Segher's suggestions here: > > https://lists.ozlabs.org/pipermail/slof/2016-August/001221.html > > IMHO we could also just simply sacrifice the first stack entry and only > use "dp = the_data_stack", without adding the inline asm here (to keep > paflof.c portable). Or you simply make the_*_stack declared as a pointer in paflof.c, not as an array. Where is it actually defined? If it is defined in assembler code all is fine; if it is defined in C code, well, don't lie to the compiler or it will take its revenge (if using full-program optimisation it can still see you're accessing the array out-of-bounds for example, or worse, assume you don't do undefined things and optimise accordingly). An easy way around is to have the_*_stack just an external symbol, and have the_real_*_stack for the arrays of cells, and then equate the two in a linker script. Or, ignore the warning. If ever things break (and they won't), it will do so with lots of fireworks; it won't silently break. Segher
diff --git a/lib/libc/include/stdio.h b/lib/libc/include/stdio.h index 84cddea..c54528f 100644 --- a/lib/libc/include/stdio.h +++ b/lib/libc/include/stdio.h @@ -51,7 +51,7 @@ int setvbuf(FILE *stream, char *buf, int mode , size_t size); int putc(int ch, FILE *stream); int putchar(int ch); -int puts(char *str); +int puts(const char *str); int scanf(const char *format, ...) __attribute__((format (scanf, 1, 2))); int fscanf(FILE *stream, const char *format, ...) __attribute__((format (scanf, 2, 3))); diff --git a/lib/libc/stdio/puts.c b/lib/libc/stdio/puts.c index 3f48dbf..9a93008 100644 --- a/lib/libc/stdio/puts.c +++ b/lib/libc/stdio/puts.c @@ -17,7 +17,7 @@ int -puts(char *str) +puts(const char *str) { int ret;
puts() does not change the string, so the parameter can be "const". Signed-off-by: Thomas Huth <thuth@redhat.com> --- lib/libc/include/stdio.h | 2 +- lib/libc/stdio/puts.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)