[RFA,2/2] Remove some clanups from solib-svr4.c
Commit Message
>> - newobj = XCNEW (struct so_list);
>> - old_chain = make_cleanup (xfree, newobj);
>> - lm_info_svr4 *li = lm_info_read (ldsomap);
>> - newobj->lm_info = li;
>> - make_cleanup (xfree, newobj->lm_info);
>> + gdb::unique_xmalloc_ptr<lm_info_svr4> li (lm_info_read (ldsomap));
Simon> This is not an error because lm_info_svr4 is trivially destructible,
Simon> but since we allocate it with "new", we might as well use a
Simon> unique_ptr, it's more future-proof.
Good catch, thanks.
Simon> How about making lm_info_read return an std::unique_ptr<lm_info_svr4>?
Simon> The patch LGTM with or without those changes.
How's this?
I re-ran it through the buildbot.
Tom
commit 0662ad7b81c11c4b23e74c1d2fcf847ca63e3a8d
Author: Tom Tromey <tom@tromey.com>
Date: Tue Mar 27 14:42:55 2018 -0600
Remove some cleanups from solib-svr4.c
This removes a few cleanups from solib-svr4.c in a straightforward
way.
gdb/ChangeLog
2018-03-30 Tom Tromey <tom@tromey.com>
* solib-svr4.c (lm_info_read): Use gdb::byte_vector. Return
std::unique_ptr.
(svr4_keep_data_in_core): Update.
(svr4_read_so_list): Update.
Comments
On 2018-03-30 15:04, Tom Tromey wrote:
>>> - newobj = XCNEW (struct so_list);
>>> - old_chain = make_cleanup (xfree, newobj);
>>> - lm_info_svr4 *li = lm_info_read (ldsomap);
>>> - newobj->lm_info = li;
>>> - make_cleanup (xfree, newobj->lm_info);
>>> + gdb::unique_xmalloc_ptr<lm_info_svr4> li (lm_info_read (ldsomap));
>
> Simon> This is not an error because lm_info_svr4 is trivially
> destructible,
> Simon> but since we allocate it with "new", we might as well use a
> Simon> unique_ptr, it's more future-proof.
>
> Good catch, thanks.
>
> Simon> How about making lm_info_read return an
> std::unique_ptr<lm_info_svr4>?
>
> Simon> The patch LGTM with or without those changes.
>
> How's this?
LGTM, I just noted two nits:
> @@ -168,28 +168,24 @@ svr4_same (struct so_list *gdb, struct so_list
> *inferior)
> return (svr4_same_1 (gdb->so_original_name,
> inferior->so_original_name));
> }
>
> -static lm_info_svr4 *
> +static std::unique_ptr<lm_info_svr4>
> lm_info_read (CORE_ADDR lm_addr)
> {
> struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
> - gdb_byte *lm;
> - lm_info_svr4 *lm_info;
> - struct cleanup *back_to;
> + std::unique_ptr<lm_info_svr4> lm_info;
>
> - lm = (gdb_byte *) xmalloc (lmo->link_map_size);
> - back_to = make_cleanup (xfree, lm);
> + gdb::byte_vector lm (lmo->link_map_size);
>
> - if (target_read_memory (lm_addr, lm, lmo->link_map_size) != 0)
> + if (target_read_memory (lm_addr, lm.data (), lmo->link_map_size) !=
> 0)
> {
> warning (_("Error reading shared library list entry at %s"),
> - paddress (target_gdbarch (), lm_addr)),
> - lm_info = NULL;
> + paddress (target_gdbarch (), lm_addr));
> }
Curly braces can be removed here.
> @@ -973,13 +965,8 @@ svr4_keep_data_in_core (CORE_ADDR vaddr, unsigned
> long size)
> if (!ldsomap)
> return 0;
>
> - newobj = XCNEW (struct so_list);
> - old_chain = make_cleanup (xfree, newobj);
> - lm_info_svr4 *li = lm_info_read (ldsomap);
> - newobj->lm_info = li;
> - make_cleanup (xfree, newobj->lm_info);
> + std::unique_ptr<lm_info_svr4> li (lm_info_read (ldsomap));
I think it's clearer to use the assignment operator in that case:
std::unique_ptr<lm_info_svr4> li = lm_info_read (ldsomap);
Simon
>>>>> "Simon" == Simon Marchi <simon.marchi@polymtl.ca> writes:
Simon> LGTM, I just noted two nits:
[...]
Thanks, I've made these changes and I'm checking it in.
Tom
@@ -1,3 +1,10 @@
+2018-03-30 Tom Tromey <tom@tromey.com>
+
+ * solib-svr4.c (lm_info_read): Use gdb::byte_vector. Return
+ std::unique_ptr.
+ (svr4_keep_data_in_core): Update.
+ (svr4_read_so_list): Update.
+
2018-03-27 Tom Tromey <tom@tromey.com>
* windows-nat.c (handle_output_debug_string, handle_exception):
@@ -168,28 +168,24 @@ svr4_same (struct so_list *gdb, struct so_list *inferior)
return (svr4_same_1 (gdb->so_original_name, inferior->so_original_name));
}
-static lm_info_svr4 *
+static std::unique_ptr<lm_info_svr4>
lm_info_read (CORE_ADDR lm_addr)
{
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
- gdb_byte *lm;
- lm_info_svr4 *lm_info;
- struct cleanup *back_to;
+ std::unique_ptr<lm_info_svr4> lm_info;
- lm = (gdb_byte *) xmalloc (lmo->link_map_size);
- back_to = make_cleanup (xfree, lm);
+ gdb::byte_vector lm (lmo->link_map_size);
- if (target_read_memory (lm_addr, lm, lmo->link_map_size) != 0)
+ if (target_read_memory (lm_addr, lm.data (), lmo->link_map_size) != 0)
{
warning (_("Error reading shared library list entry at %s"),
- paddress (target_gdbarch (), lm_addr)),
- lm_info = NULL;
+ paddress (target_gdbarch (), lm_addr));
}
else
{
struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
- lm_info = new lm_info_svr4;
+ lm_info.reset (new lm_info_svr4);
lm_info->lm_addr = lm_addr;
lm_info->l_addr_inferior = extract_typed_address (&lm[lmo->l_addr_offset],
@@ -203,8 +199,6 @@ lm_info_read (CORE_ADDR lm_addr)
ptr_type);
}
- do_cleanups (back_to);
-
return lm_info;
}
@@ -958,8 +952,6 @@ svr4_keep_data_in_core (CORE_ADDR vaddr, unsigned long size)
{
struct svr4_info *info;
CORE_ADDR ldsomap;
- struct so_list *newobj;
- struct cleanup *old_chain;
CORE_ADDR name_lm;
info = get_svr4_info ();
@@ -973,13 +965,8 @@ svr4_keep_data_in_core (CORE_ADDR vaddr, unsigned long size)
if (!ldsomap)
return 0;
- newobj = XCNEW (struct so_list);
- old_chain = make_cleanup (xfree, newobj);
- lm_info_svr4 *li = lm_info_read (ldsomap);
- newobj->lm_info = li;
- make_cleanup (xfree, newobj->lm_info);
+ std::unique_ptr<lm_info_svr4> li (lm_info_read (ldsomap));
name_lm = li != NULL ? li->l_name : 0;
- do_cleanups (old_chain);
return (name_lm >= vaddr && name_lm < vaddr + size);
}
@@ -995,8 +982,7 @@ open_symbol_file_object (int from_tty)
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
int l_name_size = TYPE_LENGTH (ptr_type);
- gdb_byte *l_name_buf = (gdb_byte *) xmalloc (l_name_size);
- struct cleanup *cleanups = make_cleanup (xfree, l_name_buf);
+ gdb::byte_vector l_name_buf (l_name_size);
struct svr4_info *info = get_svr4_info ();
symfile_add_flags add_flags = 0;
@@ -1005,38 +991,26 @@ open_symbol_file_object (int from_tty)
if (symfile_objfile)
if (!query (_("Attempt to reload symbols from process? ")))
- {
- do_cleanups (cleanups);
- return 0;
- }
+ return 0;
/* Always locate the debug struct, in case it has moved. */
info->debug_base = 0;
if (locate_base (info) == 0)
- {
- do_cleanups (cleanups);
- return 0; /* failed somehow... */
- }
+ return 0; /* failed somehow... */
/* First link map member should be the executable. */
lm = solib_svr4_r_map (info);
if (lm == 0)
- {
- do_cleanups (cleanups);
- return 0; /* failed somehow... */
- }
+ return 0; /* failed somehow... */
/* Read address of name from target memory to GDB. */
- read_memory (lm + lmo->l_name_offset, l_name_buf, l_name_size);
+ read_memory (lm + lmo->l_name_offset, l_name_buf.data (), l_name_size);
/* Convert the address to host format. */
- l_name = extract_typed_address (l_name_buf, ptr_type);
+ l_name = extract_typed_address (l_name_buf.data (), ptr_type);
if (l_name == 0)
- {
- do_cleanups (cleanups);
- return 0; /* No filename. */
- }
+ return 0; /* No filename. */
/* Now fetch the filename from target memory. */
target_read_string (l_name, &filename, SO_NAME_MAX_PATH_SIZE - 1, &errcode);
@@ -1045,14 +1019,12 @@ open_symbol_file_object (int from_tty)
{
warning (_("failed to read exec filename from attached file: %s"),
safe_strerror (errcode));
- do_cleanups (cleanups);
return 0;
}
/* Have a pathname: read the symbol file. */
symbol_file_add_main (filename.get (), add_flags);
- do_cleanups (cleanups);
return 1;
}
@@ -1342,7 +1314,7 @@ svr4_read_so_list (CORE_ADDR lm, CORE_ADDR prev_lm,
so_list_up newobj (XCNEW (struct so_list));
- lm_info_svr4 *li = lm_info_read (lm);
+ lm_info_svr4 *li = lm_info_read (lm).release ();
newobj->lm_info = li;
if (li == NULL)
return 0;