[PATCH] disassemble support start,+length format

[crquan@gmail.com]

From: CHENG Renquan <rqcheng@smu.edu.sg>

add new support for disassemble by "start,+length" format;

update ChangeLog,NEWS,doc/gdb.texinfo accordingly.

BTW, I found two disassemble Changes in GDB 7.0 in NEWS, separated in two
paragraphs, so I merged them into one.

 gdb/ChangeLog       |    8 ++++++++
 gdb/NEWS            |   13 ++++++++-----
 gdb/cli/cli-cmds.c  |   18 +++++++++++++++---
 gdb/doc/ChangeLog   |    5 +++++
 gdb/doc/gdb.texinfo |   28 +++++++++++++++++++++++++---
 5 files changed, 61 insertions(+), 11 deletions(-)

---
rebased onto cvs latest today 2010-07-09.

Index: gdb/ChangeLog
===================================================================
RCS file: /cvs/src/src/gdb/ChangeLog,v
retrieving revision 1.11979
diff -u -p -r1.11979 ChangeLog
--- gdb/ChangeLog	9 Jul 2010 02:39:57 -0000	1.11979
+++ gdb/ChangeLog	9 Jul 2010 11:23:30 -0000
@@ -1,3 +1,11 @@
+2010-07-09  CHENG Renquan  <rqcheng@smu.edu.sg>
+
+	* NEWS: Add "Changed commands" (disassemble) section for "Changes
+	since GDB 7.1"; and merge two separated paragraphs of disassemble
+	description in "Changes in GDB 7.0".
+	* cli/cli-cmds.c (disassemble_command): Add support of disassemble
+	"start,+length" form of arguments.
+
 2010-07-09  Hui Zhu  <teawater@gmail.com>
 
 	* source.c (print_source_lines_base): Add check for noprint.
Index: gdb/NEWS
===================================================================
RCS file: /cvs/src/src/gdb/NEWS,v
retrieving revision 1.392
diff -u -p -r1.392 NEWS
--- gdb/NEWS	8 Jul 2010 15:41:56 -0000	1.392
+++ gdb/NEWS	9 Jul 2010 11:23:31 -0000
@@ -184,6 +184,11 @@ strace FN | FILE:LINE | *ADDR | -m MARKE
   Define a static tracepoint by probing a marker at the given
   function, line, address, or marker ID.
 
+* Changed commands
+
+disassemble
+  The disassemble command now supports "start,+length" form of two arguments.
+
 * Python scripting
 
 ** GDB now provides a new directory location, called the python directory,
@@ -518,8 +523,9 @@ or the "condition" command is available.
 the target for evaluation using the same bytecode format as is used
 for tracepoint actions.
 
-* "disassemble" command with a /r modifier, print the raw instructions
-in hex as well as in symbolic form.
+* The disassemble command now supports: an optional /r modifier, print the
+raw instructions in hex as well as in symbolic form, and an optional /m
+modifier to print mixed source+assembly.
 
 * Process record and replay
 
@@ -611,9 +617,6 @@ qXfer:siginfo:write
   packet that permited the stub to pass a process id was removed.
   Remote servers should use the `T' stop reply packet instead.
 
-* The "disassemble" command now supports an optional /m modifier to print mixed
-source+assembly.
-
 * GDB now supports multiple function calling conventions according to the
 DWARF-2 DW_AT_calling_convention function attribute.
   
Index: gdb/cli/cli-cmds.c
===================================================================
RCS file: /cvs/src/src/gdb/cli/cli-cmds.c,v
retrieving revision 1.104
diff -u -p -r1.104 cli-cmds.c
--- gdb/cli/cli-cmds.c	17 May 2010 19:28:12 -0000	1.104
+++ gdb/cli/cli-cmds.c	9 Jul 2010 11:23:31 -0000
@@ -1108,8 +1108,9 @@ disassemble_current_function (int flags)
        - dump the assembly code for the function of the current pc
      disassemble [/mr] addr
        - dump the assembly code for the function at ADDR
-     disassemble [/mr] low high
-       - dump the assembly code in the range [LOW,HIGH)
+     disassemble [/mr] low,high
+     disassemble [/mr] low,+length
+       - dump the assembly code in the range [LOW,HIGH), or [LOW,LOW+length)
 
    A /m modifier will include source code with the assembly.
    A /r modifier will include raw instructions in hex with the assembly.  */
@@ -1180,8 +1181,18 @@ disassemble_command (char *arg, int from
   else
     {
       /* Two arguments.  */
+      int incl_flag = 0;
       low = pc;
+      while (isspace (*arg))
+	arg++;
+      if (arg[0] == '+')
+	{
+	  ++arg;
+	  incl_flag = 1;
+	}
       high = parse_and_eval_address (arg);
+      if (incl_flag)
+	high += low;
     }
 
   print_disassembly (gdbarch, name, low, high, flags);
@@ -1615,7 +1626,8 @@ Default is the function surrounding the 
 With a /m modifier, source lines are included (if available).\n\
 With a /r modifier, raw instructions in hex are included.\n\
 With a single argument, the function surrounding that address is dumped.\n\
-Two arguments (separated by a comma) are taken as a range of memory to dump."));
+Two arguments (separated by a comma) are taken as a range of memory to dump,\n\
+  in the form of \"start,end\", or \"start,+length\"."));
   set_cmd_completer (c, location_completer);
   if (xdb_commands)
     add_com_alias ("va", "disassemble", class_xdb, 0);
Index: gdb/doc/ChangeLog
===================================================================
RCS file: /cvs/src/src/gdb/doc/ChangeLog,v
retrieving revision 1.1083
diff -u -p -r1.1083 ChangeLog
--- gdb/doc/ChangeLog	1 Jul 2010 17:40:04 -0000	1.1083
+++ gdb/doc/ChangeLog	9 Jul 2010 11:23:31 -0000
@@ -1,3 +1,8 @@
+2010-07-09  CHENG Renquan  <rqcheng@smu.edu.sg>
+
+	* gdb.texinfo (Machine Code): Update description of two forms of
+	arguments, and add new example to demonstrate the new form.
+
 2010-07-01  Pedro Alves  <pedro@codesourcery.com>
 
 	* gdb.texinfo (Create and Delete Tracepoints): Add more index
Index: gdb/doc/gdb.texinfo
===================================================================
RCS file: /cvs/src/src/gdb/doc/gdb.texinfo,v
retrieving revision 1.737
diff -u -p -r1.737 gdb.texinfo
--- gdb/doc/gdb.texinfo	1 Jul 2010 17:40:04 -0000	1.737
+++ gdb/doc/gdb.texinfo	9 Jul 2010 11:23:32 -0000
@@ -6735,9 +6735,19 @@ program counter of the selected frame.  
 command is a program counter value; @value{GDBN} dumps the function
 surrounding this value.  When two arguments are given, they should
 be separated by a comma, possibly surrounded by whitespace.  The
-arguments specify a range of addresses (first inclusive, second exclusive)
-to dump.  In that case, the name of the function is also printed (since
-there could be several functions in the given range).
+arguments specify a range of addresses to dump, in one of two forms:
+
+@table @code
+@item @var{start},@var{end}
+the addresses from @var{start} (inclusive) to @var{end} (exclusive)
+@item @var{start},+@var{length}
+the addresses from @var{start} (inclusive) to
+@code{@var{start}+@var{length}} (exclusive).
+@end table
+
+@noindent
+When 2 arguments are specified, the name of the function is also
+printed (since there could be several functions in the given range).
 
 The argument(s) can be any expression yielding a numeric value, such as
 @samp{0x32c4}, @samp{&main+10} or @samp{$pc - 8}.
@@ -6789,6 +6799,18 @@ Dump of assembler code for function main
 End of assembler dump.
 @end smallexample
 
+Here is another example showing raw instructions in hex for AMD x86-64,
+
+@smallexample
+(gdb) disas /r 0x400281,+10
+Dump of assembler code from 0x400281 to 0x40028b:
+   0x0000000000400281:	 38 36	cmp    %dh,(%rsi)
+   0x0000000000400283:	 2d 36 34 2e 73	sub    $0x732e3436,%eax
+   0x0000000000400288:	 6f	outsl  %ds:(%rsi),(%dx)
+   0x0000000000400289:	 2e 32 00	xor    %cs:(%rax),%al
+End of assembler dump.
+@end smallexample
+
 Some architectures have more than one commonly-used set of instruction
 mnemonics or other syntax.
 
--
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CHENG Renquan
38 St Thomas Walk, Singapore 238118      http://crquan.fedorapeople.org