Re: [PATCH] Fix various procfs.c compilation errors

[Luis Machado <luis.machado@arm.com>]

On 11/16/22 15:02, Rainer Orth wrote:
> procfs.c has accumulated several compilation errors lately (some of them
> new with GCC 12), which are fixed by this patch:
> 
> * auxv_parse gets:
> 
> /vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c:144:7: error: ‘int procfs_target::auxv_parse(gdb_byte**, gdb_byte*, CORE_ADDR*, CORE_ADDR*)’ marked ‘override’, but does not override
>    144 |   int auxv_parse (gdb_byte **readptr,
>        |       ^~~~~~~~~~
> 
>    Obviouly, procfs.c was missed in the auxv_parse constification.
> 
> * dead_procinfo has:
> 
> /vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c: In function ‘void dead_procinfo(procinfo*, const char*, int)’:
> /vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c:563:11: warning: the address of ‘procinfo::pathname’ will never be NULL [-Waddress]
>    563 |   if (pi->pathname)
>        |       ~~~~^~~~~~~~
> /vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c:238:8: note: ‘procinfo::pathname’ declared here
>    238 |   char pathname[MAX_PROC_NAME_SIZE];    /* Pathname to /proc entry */
>        |        ^~~~~~~~
> 
>    The warning is correct, so the code can lose support for the NULL
>    pathname case.
> 
> * create_inferior has this ugly warning:
> 
> /vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c: In member function ‘virtual void procfs_target::create_inferior(const char*, const std::string&, char**, int)’:
> /vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c:2815:19: warning: ‘char* std::strncpy(char*, const char*, size_t)’ output truncated before terminating nul copying as many bytes from a string as its length [-Wstringop-truncation]
>   2815 |           strncpy (tryname, p, len);
>        |           ~~~~~~~~^~~~~~~~~~~~~~~~~
> /vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c:2814:26: note: length computed here
>   2814 |             len = strlen (p);
>        |                   ~~~~~~~^~~
> 
>    It seems that this is another case of GCC PR middle-end/88059, which
>    Martin Sebor refuses to fix.  So I'm using the hack suggested in the
>    PR to use memcpy instead of strncpy.
> 
> * find_memory_regions_callback fails with
> 
> /vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c: In function ‘int find_memory_regions_callback(prmap*, find_memory_region_ftype, void*)’:
> /vol/src/gnu/gdb/hg/master/dist/gdb/procfs.c:3167:18: error: too few arguments to function
>   3167 |   return (*func) ((CORE_ADDR) map->pr_vaddr,
>        |          ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
>   3168 |                   map->pr_size,
>        |                   ~~~~~~~~~~~~~
>   3169 |                   (map->pr_mflags & MA_READ) != 0,
>        |                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   3170 |                   (map->pr_mflags & MA_WRITE) != 0,
>        |                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   3171 |                   (map->pr_mflags & MA_EXEC) != 0,
>        |                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   3172 |                   1, /* MODIFIED is unknown, pass it as true.  */
>        |                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   3173 |                   data);
>        |                   ~~~~~
> 
>    Again, procfs.c was overlooked when adding the new memory_tagged arg.
>    Unfortunately, it wasn't even documented in gdb/defs.h when it was
>    added in
> 

Sorry, that was an oversight. I failed to updated all the hooks. I think there was a BSD one that got fixed after the following commit was pushed.

> commit 68cffbbd4406b4efe1aa6e18460b1d7ca02549f1
> Author: Luis Machado <luis.machado@arm.com>
> Date:   Thu Mar 31 11:42:35 2022 +0100
> 
>      [AArch64] MTE corefile support
> 
> With those changes, procfs.c compiles again.  Together with the hack
> from the Solaris gdbsupport breakage reported in PR build/29791, I was
> able to build and test gdb on both amd64-pc-solaris2.11 and
> sparcv9-sun-solaris2.11.
> 
> Will commit the patch soon.
> 
> 	Rainer
>