Mirror of the gdb-patches mailing list
 help / color / mirror / Atom feed
From: Andreas Arnez <arnez@linux.vnet.ibm.com>
To: gdb-patches@sourceware.org
Subject: [PATCH 2/4] tui-disasm: Fix line buffer size calculation
Date: Tue, 08 Nov 2016 18:59:00 -0000	[thread overview]
Message-ID: <1478631454-9447-3-git-send-email-arnez@linux.vnet.ibm.com> (raw)
In-Reply-To: <1478631454-9447-1-git-send-email-arnez@linux.vnet.ibm.com>

The code that fills the TUI disassembly window content first calculates
the maximum full length of a displayed disassembly line.  This
calculation typically yields the wrong result.  The result is too large,
so the bug does not cause any run-time failures, but unnecessary
confusion for the reader.  This patch fixes the calculation.

gdb/ChangeLog:

	* tui/tui-disasm.c (tui_set_disassem_content): Fix calculation of
	the longest disassembly line's length.
---
 gdb/tui/tui-disasm.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/gdb/tui/tui-disasm.c b/gdb/tui/tui-disasm.c
index 5368aa4..6811be3 100644
--- a/gdb/tui/tui-disasm.c
+++ b/gdb/tui/tui-disasm.c
@@ -178,7 +178,7 @@ tui_set_disassem_content (struct gdbarch *gdbarch, CORE_ADDR pc)
   int tab_len = tui_default_tab_len ();
   struct tui_asm_line *asm_lines;
   int insn_pos;
-  int addr_size, max_size;
+  int addr_size, insn_size;
   char *line;
   
   if (pc == 0)
@@ -203,9 +203,9 @@ tui_set_disassem_content (struct gdbarch *gdbarch, CORE_ADDR pc)
 
   tui_disassemble (gdbarch, asm_lines, pc, max_lines);
 
-  /* See what is the maximum length of an address and of a line.  */
+  /* Determine maximum address- and instruction lengths.  */
   addr_size = 0;
-  max_size = 0;
+  insn_size = 0;
   for (i = 0; i < max_lines; i++)
     {
       size_t len = strlen (asm_lines[i].addr_string);
@@ -213,16 +213,17 @@ tui_set_disassem_content (struct gdbarch *gdbarch, CORE_ADDR pc)
       if (len > addr_size)
         addr_size = len;
 
-      len = strlen (asm_lines[i].insn) + tab_len;
-      if (len > max_size)
-        max_size = len;
+      len = strlen (asm_lines[i].insn);
+      if (len > insn_size)
+	insn_size = len;
     }
-  max_size += addr_size + tab_len;
 
-  /* Allocate memory to create each line.  */
-  line = (char*) alloca (max_size);
+  /* Align instructions to the same column.  */
   insn_pos = (1 + (addr_size / tab_len)) * tab_len;
 
+  /* Allocate memory to create each line.  */
+  line = (char*) alloca (insn_pos + insn_size + 1);
+
   /* Now construct each line.  */
   for (i = 0; i < max_lines; i++)
     {
-- 
2.5.0


  parent reply	other threads:[~2016-11-08 18:59 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-08 18:57 [PATCH 0/4] Some TUI fixes Andreas Arnez
2016-11-08 18:58 ` [PATCH 1/4] tui-disasm: Fix window content buffer overrun Andreas Arnez
2016-11-08 19:29   ` Pedro Alves
2016-11-09 12:07     ` Andreas Arnez
2016-11-08 18:59 ` [PATCH 3/4] tui-winsource: Allocate for actual lines only Andreas Arnez
2016-11-08 19:31   ` Pedro Alves
2016-11-08 18:59 ` Andreas Arnez [this message]
2016-11-08 19:30   ` [PATCH 2/4] tui-disasm: Fix line buffer size calculation Pedro Alves
2016-11-08 19:00 ` [PATCH 4/4] tui-winsource: Remove failed-allocation logic Andreas Arnez
2016-11-08 19:31   ` Pedro Alves

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1478631454-9447-3-git-send-email-arnez@linux.vnet.ibm.com \
    --to=arnez@linux.vnet.ibm.com \
    --cc=gdb-patches@sourceware.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox