From: Simon Marchi <simon.marchi@ericsson.com>
To: Tom Tromey <tom@tromey.com>, <gdb-patches@sourceware.org>
Subject: Re: [RFA 1/6] Use std::vector in end_symtab_get_static_block
Date: Mon, 16 Oct 2017 20:18:00 -0000 [thread overview]
Message-ID: <1cd5418f-2ae8-dcb4-3a00-48bb85fc49c1@ericsson.com> (raw)
In-Reply-To: <20171016030427.21349-2-tom@tromey.com>
On 2017-10-15 11:04 PM, Tom Tromey wrote:
> Change end_symtab_get_static_block to use std::vector. This removes a
> cleanup.
>
> ChangeLog
> 2017-10-15 Tom Tromey <tom@tromey.com>
>
> * buildsym.c (block_compar): Remove.
> (end_symtab_get_static_block): Use std::vector.
> ---
> gdb/ChangeLog | 5 +++++
> gdb/buildsym.c | 38 ++++++++++----------------------------
> 2 files changed, 15 insertions(+), 28 deletions(-)
>
> diff --git a/gdb/buildsym.c b/gdb/buildsym.c
> index cbad027d0c..c3cfc37cd6 100644
> --- a/gdb/buildsym.c
> +++ b/gdb/buildsym.c
> @@ -86,6 +86,7 @@
> #include "cp-support.h"
> #include "dictionary.h"
> #include "addrmap.h"
> +#include <algorithm>
>
> /* Ask buildsym.h to define the vars it normally declares `extern'. */
> #define EXTERN
> @@ -1165,19 +1166,6 @@ watch_main_source_file_lossage (void)
> }
> }
>
> -/* Helper function for qsort. Parameters are `struct block *' pointers,
> - function sorts them in descending order by their BLOCK_START. */
> -
> -static int
> -block_compar (const void *ap, const void *bp)
> -{
> - const struct block *a = *(const struct block **) ap;
> - const struct block *b = *(const struct block **) bp;
> -
> - return ((BLOCK_START (b) > BLOCK_START (a))
> - - (BLOCK_START (b) < BLOCK_START (a)));
> -}
> -
> /* Reset state after a successful building of a symtab.
> This exists because dbxread.c and xcoffread.c can call
> start_symtab+end_symtab multiple times after one call to buildsym_init,
> @@ -1254,28 +1242,22 @@ end_symtab_get_static_block (CORE_ADDR end_addr, int expandable, int required)
>
> if ((objfile->flags & OBJF_REORDERED) && pending_blocks)
> {
> - unsigned count = 0;
> struct pending_block *pb;
> - struct block **barray, **bp;
> - struct cleanup *back_to;
> -
> - for (pb = pending_blocks; pb != NULL; pb = pb->next)
> - count++;
>
> - barray = XNEWVEC (struct block *, count);
> - back_to = make_cleanup (xfree, barray);
> + std::vector<block *> barray;
>
> - bp = barray;
> for (pb = pending_blocks; pb != NULL; pb = pb->next)
> - *bp++ = pb->block;
> + barray.push_back (pb->block);
>
> - qsort (barray, count, sizeof (*barray), block_compar);
> + std::sort (barray.begin (), barray.end (),
> + [] (const block *a, const block *b)
> + {
> + return BLOCK_START (a) > BLOCK_START (b);
That made me doubt for a second, since we're more used to see "<"
in these functions. I then saw that block_compar did sort them
in descending order. Could you add a comment here to indicate that?
> + });
>
> - bp = barray;
> + int i = 0;
> for (pb = pending_blocks; pb != NULL; pb = pb->next)
> - pb->block = *bp++;
> -
> - do_cleanups (back_to);
> + pb->block = barray[i++];
> }
I thought, why don't we replace pending_blocks by a vector and sort that in place
rather than copy the pointers to a temporary vector and copy them back, but it's
not easy and may not even be what we want.
LGTM with the comment added.
Simon
next prev parent reply other threads:[~2017-10-16 20:18 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-16 3:04 [RFA 0/6] more cleanup removals Tom Tromey
2017-10-16 3:04 ` [RFA 6/6] Return unique_xmalloc_ptr from target_fileio_read_stralloc Tom Tromey
2017-10-16 21:07 ` Simon Marchi
2017-10-16 3:04 ` [RFA 1/6] Use std::vector in end_symtab_get_static_block Tom Tromey
2017-10-16 20:18 ` Simon Marchi [this message]
2017-10-16 21:59 ` Tom Tromey
2017-10-20 15:33 ` Ulrich Weigand
2017-10-20 16:47 ` Pedro Alves
2017-10-23 16:16 ` Ulrich Weigand
2017-10-24 13:55 ` Tom Tromey
2017-10-24 14:41 ` [pushed] " Ulrich Weigand
2017-10-16 3:04 ` [RFA 3/6] Remove cleanup from ppc-linux-nat.c Tom Tromey
2017-10-16 20:28 ` Simon Marchi
2017-10-16 3:04 ` [RFA 5/6] Return unique_xmalloc_ptr from target_read_stralloc Tom Tromey
2017-10-16 21:02 ` Simon Marchi
2017-10-16 3:04 ` [RFA 2/6] Remove some cleanups from probe.c Tom Tromey
2017-10-16 20:26 ` Simon Marchi
2017-10-16 3:04 ` [RFA 4/6] Simple cleanup removals in remote.c Tom Tromey
2017-10-16 20:43 ` Simon Marchi
2017-10-16 21:14 ` Tom Tromey
2017-10-16 21:37 ` Simon Marchi
2017-10-16 21:50 ` Tom Tromey
2017-10-16 22:35 ` Pedro Alves
2017-10-16 23:00 ` Tom Tromey
2017-10-16 23:34 ` [PATCH 1/2] Introduce string_appendf/string_vappendf (Re: [RFA 4/6] Simple cleanup removals in remote.c) Pedro Alves
2017-10-19 3:11 ` Simon Marchi
2017-10-19 3:13 ` Simon Marchi
2017-10-30 0:16 ` Simon Marchi
2017-10-30 11:48 ` Pedro Alves
2017-10-16 23:38 ` [PATCH 2/2] remote.c, QCatchSyscalls: Build std::string instead of unique_xmalloc_ptr " Pedro Alves
2017-10-19 3:17 ` Simon Marchi
2017-10-30 11:49 ` Pedro Alves
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