[RFC] mi: add -a option to the "-data-disassemble" command

Message ID 20180810082953.8426-1-jan.vrany@fit.cvut.cz
State Superseded
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Series
  • [RFC] mi: add -a option to the "-data-disassemble" command
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Commit Message

Jan Vrany Aug. 10, 2018, 8:29 a.m.
A CLI command "disassemble" allows use to specify a single
address - in that case function surrounding that address is
disassembled.

This commit adds this feature to MI command "-data-disassemble".

gdb/ChangeLog:

	* mi/mi-cmd-disas.c (mi_cmd_disassemble): Added -a option.
	If used, use find_pc_partial_function to find address range
	to disassemble.
	* mi/mi-main.c (mi/mi-main.c): Add new feature
	data-disassemble-a-option to indicate that -data-disassemble
	supports -a.
	* NEWS: Mention new -data-disassemble option -a

gdb/doc/ChangeLog:

	* gdb.texinfo (GDB/MI Data Manipulation): Document
	"-data-disassemble -a addr".
	(GDB/MI Support Commands): Document data-disassemble-a-option
	feature

gdb/testsuite/ChangeLog:

	* gdb.mi/mi-disassemble.exp (test_disassembly_only): Added
	tests for -data-disassemble -a.
	(test_disassembly_bogus_args): Likewise.
---
 gdb/ChangeLog                           | 10 +++++++
 gdb/NEWS                                |  3 +++
 gdb/doc/ChangeLog                       |  7 +++++
 gdb/doc/gdb.texinfo                     |  9 +++++++
 gdb/mi/mi-cmd-disas.c                   | 35 +++++++++++++++++++------
 gdb/mi/mi-main.c                        |  1 +
 gdb/testsuite/ChangeLog                 |  6 +++++
 gdb/testsuite/gdb.mi/mi-disassemble.exp | 20 ++++++++++++--
 8 files changed, 81 insertions(+), 10 deletions(-)

-- 
2.18.0

Comments

Pedro Alves Aug. 10, 2018, 9:47 a.m. | #1
On 08/10/2018 09:29 AM, Jan Vrany wrote:
> @@ -33095,6 +33101,9 @@ records, produced when trying to execute an undefined @sc{gdb/mi} command

>  @item exec-run-start-option

>  Indicates that the @code{-exec-run} command supports the @option{--start}

>  option (@pxref{GDB/MI Program Execution}).

> +@item data-disassemble-a-option

> +Indicates that the @code{-data-disassemble} command supports the @option{-a}

> +option (@pxref{GDB/MI Data Manipulation}).

>  @end ftable


I'm curious about how you intend to use this new -list-features feature.
Are you enabling/disabling some UI element depending on presence of the
feature?  I.e., something that you wouldn't be able to do by just
trying the "-data-disassemble -a" command and looking for error?

Thanks,
Pedro Alves
Jan Vrany Aug. 10, 2018, 10:28 a.m. | #2
On Fri, 2018-08-10 at 10:47 +0100, Pedro Alves wrote:
> On 08/10/2018 09:29 AM, Jan Vrany wrote:

> > @@ -33095,6 +33101,9 @@ records, produced when trying to execute an undefined @sc{gdb/mi} command

> >  @item exec-run-start-option

> >  Indicates that the @code{-exec-run} command supports the @option{--start}

> >  option (@pxref{GDB/MI Program Execution}).

> > +@item data-disassemble-a-option

> > +Indicates that the @code{-data-disassemble} command supports the @option{-a}

> > +option (@pxref{GDB/MI Data Manipulation}).

> >  @end ftable

> 

> I'm curious about how you intend to use this new -list-features feature.

> Are you enabling/disabling some UI element depending on presence of the

> feature?  I.e., something that you wouldn't be able to do by just

> trying the "-data-disassemble -a" command and looking for error?


Yes. Basically I have a menu item on frame that opens another window with
disassembly of the coresponding function (showing current instruction, 
(basic) blocks and alike). 

For programs with debug information, I can do that even without -a option. 
For programs without debug information, I need -a option and - to make the
frontend robust w.r.t UX - I disable the menu item. 

I can indeed just try and catch the error, but this seems to be too heavyweight.
It would mean to disassemble function whenever user switches frames in the 
UI or in CLI. I can cache the result, but still. This new feature just makes
it trivial and fast enough (no MI roundtrip to enable/disable menu item)

That being said, I do not insist on having this feature. I'm close to the point
of just saying "you need to use my patched GDB, anyway.  At least for "now" and 
hope that my patches will eventually make it into official GDB release. Not a big 
deal for me, not at all. 

So, if you (meaning you maintainers) prefer not having this feature, I'll just remove 
it. Absolutely no problem! Just let me know. 

Jan
Pedro Alves Aug. 10, 2018, 10:41 a.m. | #3
On 08/10/2018 11:28 AM, Jan Vrany wrote:
> On Fri, 2018-08-10 at 10:47 +0100, Pedro Alves wrote:

>> On 08/10/2018 09:29 AM, Jan Vrany wrote:

>>> @@ -33095,6 +33101,9 @@ records, produced when trying to execute an undefined @sc{gdb/mi} command

>>>  @item exec-run-start-option

>>>  Indicates that the @code{-exec-run} command supports the @option{--start}

>>>  option (@pxref{GDB/MI Program Execution}).

>>> +@item data-disassemble-a-option

>>> +Indicates that the @code{-data-disassemble} command supports the @option{-a}

>>> +option (@pxref{GDB/MI Data Manipulation}).

>>>  @end ftable

>>

>> I'm curious about how you intend to use this new -list-features feature.

>> Are you enabling/disabling some UI element depending on presence of the

>> feature?  I.e., something that you wouldn't be able to do by just

>> trying the "-data-disassemble -a" command and looking for error?

> 

> Yes. Basically I have a menu item on frame that opens another window with

> disassembly of the coresponding function (showing current instruction, 

> (basic) blocks and alike). 

> 

> For programs with debug information, I can do that even without -a option. 

> For programs without debug information, I need -a option and - to make the

> frontend robust w.r.t UX - I disable the menu item. 

> 

> I can indeed just try and catch the error, but this seems to be too heavyweight.

> It would mean to disassemble function whenever user switches frames in the 

> UI or in CLI. I can cache the result, but still. This new feature just makes

> it trivial and fast enough (no MI roundtrip to enable/disable menu item)


Ahah, thanks.  (IMHO, that's useful info that include in a submission that
proposes a -list-features addition.)

> 

> That being said, I do not insist on having this feature. I'm close to the point

> of just saying "you need to use my patched GDB, anyway.  At least for "now" and 

> hope that my patches will eventually make it into official GDB release. Not a big 

> deal for me, not at all. 

> 

> So, if you (meaning you maintainers) prefer not having this feature, I'll just remove 

> it. Absolutely no problem! Just let me know. 


I was really just curious.  And TBC, I was just talking about the -list-features
entry, not the actual whole "-a" feature added by the patch, which I agree is useful.

> --- a/gdb/NEWS

> +++ b/gdb/NEWS

> @@ -3,6 +3,9 @@

>  

>  *** Changes since GDB 8.1

>  

> +* The '-data-disassemble' MI command now accepts the '-a' option to disassemble

> +  the whole function surrounding given program counter value or function name.


This should be moved to the "since 8.2" section.

Thanks,
Pedro Alves

Patch

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0f601bdbf0..53a417706f 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,13 @@ 
+2018-07-05  Jan Vrany  <jan.vrany@fit.cvut.cz>
+
+	* mi/mi-cmd-disas.c (mi_cmd_disassemble): Added -a option.
+	If used, use find_pc_partial_function to find address range
+	to disassemble.
+	* mi/mi-main.c (mi/mi-main.c): Add new feature
+	data-disassemble-a-option to indicate that -data-disassemble
+	supports -a.
+	* NEWS: Mention new -data-disassemble option -a
+
 2018-07-02  Sebastian Huber  <sebastian.huber@embedded-brains.de>
 
 	* riscv-tdep.c (riscv_register_aliases): Swap "fp" and "s0" entries.
diff --git a/gdb/NEWS b/gdb/NEWS
index 839466e7e0..19f353495b 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -3,6 +3,9 @@ 
 
 *** Changes since GDB 8.1
 
+* The '-data-disassemble' MI command now accepts the '-a' option to disassemble
+  the whole function surrounding given program counter value or function name.
+
 * The 'symbol-file' command now accepts an '-o' option to add a relative
   offset to all sections.
 
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 6954398e43..f52074f2df 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,10 @@ 
+2018-07-05  Jan Vrany  <jan.vrany@fit.cvut.cz>
+
+	* gdb.texinfo (GDB/MI Data Manipulation): Document
+	"-data-disassemble -a addr".
+	(GDB/MI Support Commands): Document data-disassemble-a-option
+	feature
+
 2018-06-28  Petr Tesarik  <ptesarik@suse.cz>
 
 	* gdb.texinfo (Files): Document "add-symbol-file -o offset".
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 7fb6ac5636..47acf6cdd0 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -30947,6 +30947,7 @@  For details about what an addressable memory unit is,
 @smallexample
  -data-disassemble
     [ -s @var{start-addr} -e @var{end-addr} ]
+  | [ -a @var{addr} ]
   | [ -f @var{filename} -l @var{linenum} [ -n @var{lines} ] ]
   -- @var{mode}
 @end smallexample
@@ -30959,6 +30960,11 @@  Where:
 is the beginning address (or @code{$pc})
 @item @var{end-addr}
 is the end address
+@item @var{addr}
+is the address anywhere in function code (or function name).  If @code{-a}
+@var{addr} is used, the whole function surrounding that address will be
+disassembled. If @var{addr} is a function name, the whole function with that
+name will be disassembled.
 @item @var{filename}
 is the name of the file to disassemble
 @item @var{linenum}
@@ -33095,6 +33101,9 @@  records, produced when trying to execute an undefined @sc{gdb/mi} command
 @item exec-run-start-option
 Indicates that the @code{-exec-run} command supports the @option{--start}
 option (@pxref{GDB/MI Program Execution}).
+@item data-disassemble-a-option
+Indicates that the @code{-data-disassemble} command supports the @option{-a}
+option (@pxref{GDB/MI Data Manipulation}).
 @end ftable
 
 @subheading The @code{-list-target-features} Command
diff --git a/gdb/mi/mi-cmd-disas.c b/gdb/mi/mi-cmd-disas.c
index e704e35b34..8f0b126fb3 100644
--- a/gdb/mi/mi-cmd-disas.c
+++ b/gdb/mi/mi-cmd-disas.c
@@ -67,6 +67,7 @@  mi_cmd_disassemble (const char *command, char **argv, int argc)
   int num_seen = 0;
   int start_seen = 0;
   int end_seen = 0;
+  int addr_seen = 0;
 
   /* ... and their corresponding value. */
   char *file_string = NULL;
@@ -74,13 +75,14 @@  mi_cmd_disassemble (const char *command, char **argv, int argc)
   int how_many = -1;
   CORE_ADDR low = 0;
   CORE_ADDR high = 0;
+  CORE_ADDR addr = 0;
 
   /* Options processing stuff.  */
   int oind = 0;
   char *oarg;
   enum opt
   {
-    FILE_OPT, LINE_OPT, NUM_OPT, START_OPT, END_OPT
+    FILE_OPT, LINE_OPT, NUM_OPT, START_OPT, END_OPT, ADDR_OPT
   };
   static const struct mi_opt opts[] =
     {
@@ -89,6 +91,7 @@  mi_cmd_disassemble (const char *command, char **argv, int argc)
       {"n", NUM_OPT, 1},
       {"s", START_OPT, 1},
       {"e", END_OPT, 1},
+      {"a", ADDR_OPT, 1},
       { 0, 0, 0 }
     };
 
@@ -122,23 +125,33 @@  mi_cmd_disassemble (const char *command, char **argv, int argc)
 	  high = parse_and_eval_address (oarg);
 	  end_seen = 1;
 	  break;
+	case ADDR_OPT:
+	  addr = parse_and_eval_address (oarg);
+	  addr_seen = 1;
+	  break;
 	}
     }
   argv += oind;
   argc -= oind;
 
   /* Allow only filename + linenum (with how_many which is not
-     required) OR start_addr + end_addr.  */
+     required) OR start_addr + end_addr OR addr  */
+
+  if (!(
+          ( line_seen &&  file_seen &&              !start_seen && !end_seen
+								&& !addr_seen)
+
+       || (!line_seen && !file_seen && !num_seen &&  start_seen &&  end_seen
+								&& !addr_seen)
 
-  if (!((line_seen && file_seen && num_seen && !start_seen && !end_seen)
-	|| (line_seen && file_seen && !num_seen && !start_seen && !end_seen)
-	|| (!line_seen && !file_seen && !num_seen && start_seen && end_seen)))
+       || (!line_seen && !file_seen && !num_seen && !start_seen && !end_seen
+								&&  addr_seen)))
     error (_("-data-disassemble: Usage: ( [-f filename -l linenum [-n "
-	     "howmany]] | [-s startaddr -e endaddr]) [--] mode."));
+	     "howmany]] | [-s startaddr -e endaddr] | [-a addr] ) [--] mode."));
 
   if (argc != 1)
-    error (_("-data-disassemble: Usage: [-f filename -l linenum "
-	     "[-n howmany]] [-s startaddr -e endaddr] [--] mode."));
+    error (_("-data-disassemble: Usage: ( [-f filename -l linenum [-n "
+             "howmany]] | [-s startaddr -e endaddr] | [-a addr] ) [--] mode."));
 
   mode = atoi (argv[0]);
   if (mode < 0 || mode > 5)
@@ -184,6 +197,12 @@  mi_cmd_disassemble (const char *command, char **argv, int argc)
 	error (_("-data-disassemble: "
 		 "No function contains specified address"));
     }
+  else if (addr_seen) 
+    {
+      if (find_pc_partial_function (addr, NULL, &low, &high) == 0)
+        error (_("-data-disassemble: "
+                 "No function contains specified address"));
+    }
 
   gdb_disassembly (gdbarch, uiout,
   		   disasm_flags,
diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index 2177abd0ed..f503b3149e 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -1683,6 +1683,7 @@  mi_cmd_list_features (const char *command, char **argv, int argc)
       uiout->field_string (NULL, "info-gdb-mi-command");
       uiout->field_string (NULL, "undefined-command-error-code");
       uiout->field_string (NULL, "exec-run-start-option");
+      uiout->field_string (NULL, "data-disassemble-a-option");
 
       if (ext_lang_initialized_p (get_ext_lang_defn (EXT_LANG_PYTHON)))
 	uiout->field_string (NULL, "python");
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 93c849c040..11d1440535 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,9 @@ 
+2018-07-05  Jan Vrany  <jan.vrany@fit.cvut.cz>
+
+	* gdb.mi/mi-disassemble.exp (test_disassembly_only): Added
+	tests for -data-disassemble -a.
+	(test_disassembly_bogus_args): Likewise.
+
 2018-06-29  Pedro Alves  <palves@redhat.com>
 
 	* gdb.threads/names.exp: Adjust expected "info threads" output.
diff --git a/gdb/testsuite/gdb.mi/mi-disassemble.exp b/gdb/testsuite/gdb.mi/mi-disassemble.exp
index 6b1fcf5884..393e8b35b5 100644
--- a/gdb/testsuite/gdb.mi/mi-disassemble.exp
+++ b/gdb/testsuite/gdb.mi/mi-disassemble.exp
@@ -46,13 +46,24 @@  proc test_disassembly_only {} {
     # Test disassembly more only for the current function.
     # Tests:
     # -data-disassemble -s $pc -e "$pc+8" -- 0
+    # -data-disassemble -a $pc -- 0
+    # -data-disassemble -a callee4 -- 0
     # -data-disassembly -f basics.c -l $line_main_body -- 0
 
+
     mi_gdb_test "print/x \$pc" "" ""
     mi_gdb_test "111-data-disassemble -s \$pc -e \"\$pc + 12\" -- 0" \
 	    "111\\^done,asm_insns=\\\[\{address=\"$hex\",func-name=\"main\",offset=\"$decimal\",inst=\".*\"\},\{address=\"$hex\",func-name=\"main\",offset=\"$decimal\",inst=\".*\"\}.*\]" \
              "data-disassemble from pc to pc+12 assembly only"
 
+    mi_gdb_test "112-data-disassemble -a \$pc -- 0" \
+	    "112\\^done,asm_insns=\\\[\{address=\"$hex\",func-name=\"main\",offset=\"$decimal\",inst=\".*\"\},\{address=\"$hex\",func-name=\"main\",offset=\"$decimal\",inst=\".*\"\}.*\]" \
+             "data-disassemble function around pc assembly only"
+
+    mi_gdb_test "113-data-disassemble -a callee4 -- 0" \
+	    "113\\^done,asm_insns=\\\[\{address=\"$hex\",func-name=\"callee4\",offset=\"$decimal\",inst=\".*\"\},\{address=\"$hex\",func-name=\"callee4\",offset=\"$decimal\",inst=\".*\"\}.*\]" \
+             "data-disassemble function callee4 assembly only"
+
     mi_gdb_test "222-data-disassemble  -f basics.c -l $line_main_body -- 0" \
 	    "222\\^done,asm_insns=\\\[\{address=\"$hex\",func-name=\"main\",offset=\"0\",inst=\".*\"\},.*,\{address=\"$hex\",func-name=\"main\",offset=\"$decimal\",inst=\".*\"\}\\\]" \
               "data-disassemble file & line, assembly only"
@@ -207,6 +218,7 @@  proc test_disassembly_bogus_args {} {
     # Tests:
     # -data-disassembly -f foo -l abc -n 0 -- 0
     # -data-disassembly -s foo -e bar -- 0
+    # -data-disassembly -a foo -- 0
     # -data-disassembly -s $pc -f basics.c -- 0
     # -data-disassembly -f basics.c -l 32 -- 9
 
@@ -216,10 +228,14 @@  proc test_disassembly_bogus_args {} {
 
     mi_gdb_test "321-data-disassemble -s foo -e bar -- 0" \
              "321\\^error,msg=\"No symbol \\\\\"foo\\\\\" in current context.\"" \
-             "data-disassemble bogus address"
+             "data-disassemble bogus address (-s -e)"
+
+    mi_gdb_test "322-data-disassemble -a foo -- 0" \
+             "322\\^error,msg=\"No symbol \\\\\"foo\\\\\" in current context.\"" \
+             "data-disassemble bogus address (-a)"
 
     mi_gdb_test "456-data-disassemble -s \$pc -f basics.c -- 0" \
-             "456\\^error,msg=\"-data-disassemble: Usage: \\( .-f filename -l linenum .-n howmany.. \\| .-s startaddr -e endaddr.\\) .--. mode.\"" \
+             "456\\^error,msg=\"-data-disassemble: Usage: \\( .-f filename -l linenum .-n howmany.. \\| .-s startaddr -e endaddr. \\| .-a addr. \\) .--. mode.\"" \
              "data-disassemble mix different args"
 
     mi_gdb_test "789-data-disassemble -f basics.c -l $line_main_body -- 9" \