gdb: fix symtab.c build on 32 bit targets
Commit Message
When building on Ubuntu 22.04, gcc 12, x86-64 with -m32 and -O2, I get:
CXX symtab.o
/home/smarchi/src/binutils-gdb/gdb/symtab.c: In member function ‘std::vector<symbol_search> global_symbol_searcher::search() const’:
/home/smarchi/src/binutils-gdb/gdb/symtab.c:4961:44: error: ‘__builtin___sprintf_chk’ may write a terminating nul past the end of the destination [-Werror=format-overflow=]
4961 | sprintf (tmp, "operator%.*s%s", fix, " ", opname);
| ^
In file included from /usr/include/stdio.h:894,
from ../gnulib/import/stdio.h:43,
from /home/smarchi/src/binutils-gdb/gdb/../gdbsupport/common-defs.h:86,
from /home/smarchi/src/binutils-gdb/gdb/defs.h:28,
from /home/smarchi/src/binutils-gdb/gdb/symtab.c:20:
In function ‘int sprintf(char*, const char*, ...)’,
inlined from ‘std::vector<symbol_search> global_symbol_searcher::search() const’ at /home/smarchi/src/binutils-gdb/gdb/symtab.c:4961:16:
/usr/include/i386-linux-gnu/bits/stdio2.h:38:34: note: ‘__builtin___sprintf_chk’ output between 9 and 2147483648 bytes into a destination of size 2147483647
38 | return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1,
| ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
39 | __glibc_objsize (__s), __fmt,
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
40 | __va_arg_pack ());
| ~~~~~~~~~~~~~~~~~
PR 29798 shows a similar error message but on Solaris.
Work around that by using string_printf. It is a good thing to get rid
of the alloca anyway.
Change-Id: Ifbac11fee3062ad7f134d596b4e2229dc5d166f9
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29798
---
gdb/symtab.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
Comments
>>>>> "Simon" == Simon Marchi via Gdb-patches <gdb-patches@sourceware.org> writes:
Simon> PR 29798 shows a similar error message but on Solaris.
It should say "PR build/29798" here, so the commit script can pick it
up.
Simon> Work around that by using string_printf. It is a good thing to get rid
Simon> of the alloca anyway.
Indeed. IMO alloca should be poisoned.
The patch looks good to me.
Simon> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29798
... we should teach that commit script to pick this up.
I don't know how to access it, though.
Tom
On 11/18/22 10:37, Tom Tromey wrote:
>>>>>> "Simon" == Simon Marchi via Gdb-patches <gdb-patches@sourceware.org> writes:
>
> Simon> PR 29798 shows a similar error message but on Solaris.
>
> It should say "PR build/29798" here, so the commit script can pick it
> up.
Fixed.
>
> Simon> Work around that by using string_printf. It is a good thing to get rid
> Simon> of the alloca anyway.
>
> Indeed. IMO alloca should be poisoned.
> The patch looks good to me.
Thanks, will push.
>
> Simon> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29798
>
> ... we should teach that commit script to pick this up.
> I don't know how to access it, though.
I will ask Joel.
Simon
@@ -4928,6 +4928,7 @@ global_symbol_searcher::search () const
if (m_symbol_name_regexp != NULL)
{
const char *symbol_name_regexp = m_symbol_name_regexp;
+ std::string symbol_name_regexp_holder;
/* Make sure spacing is right for C++ operators.
This is just a courtesy to make the matching less sensitive
@@ -4956,10 +4957,9 @@ global_symbol_searcher::search () const
/* If wrong number of spaces, fix it. */
if (fix >= 0)
{
- char *tmp = (char *) alloca (8 + fix + strlen (opname) + 1);
-
- sprintf (tmp, "operator%.*s%s", fix, " ", opname);
- symbol_name_regexp = tmp;
+ symbol_name_regexp_holder
+ = string_printf ("operator%.*s%s", fix, " ", opname);
+ symbol_name_regexp = symbol_name_regexp_holder.c_str ();
}
}