8 Commits

Author SHA1 Message Date
Jason Molenda
daba823622 Refine error msgs from CommandObject & Disassemble
Make it clearer for end users why a command cannot be used
when a process is not stopped, etc.

Differential Revision: https://reviews.llvm.org/D120594
2022-03-02 11:17:48 -08:00
Med Ismail Bennani
b889ef4214 [lldb/Core] Change large function threshold variable into a setting.
This patch replaces the static large function threshold variable with a
global debugger setting (`stop-disassembly-max-size`).

The default threshold is now set to 32KB (instead of 8KB) and can be modified.

rdar://74726362

Differential Revision: https://reviews.llvm.org/D97486

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2021-02-25 22:35:04 +01:00
Raphael Isemann
6201017d54 [lldb] Prevent double new lines behind errors/warning/messages from LLDB commands
The current API for printing errors/warnings/messages from LLDB commands
sometimes adds newlines behind the messages for the caller. However, this
happens unconditionally so when the caller already specified a trailing newline
in the error message (or is trying to print a generated error message that ends
in a newline), LLDB ends up printing both the automatically added newline and
the one that was in the error message string. This leads to all the randomly
appearing new lines in error such as:

```
(lldb) command a
error: 'command alias' requires at least two arguments
(lldb) apropos a b
error: 'apropos' must be called with exactly one argument.

(lldb) why is there an empty line behind the second error?
```

This code adds a check that only appends the new line if the passed message
doesn't already contain a trailing new line.

Also removes the AppendRawWarning which had only one caller and doesn't serve
any purpose now.

Reviewed By: #lldb, mib

Differential Revision: https://reviews.llvm.org/D96947
2021-02-24 14:42:01 +01:00
Pavel Labath
8b845ac5ed Recommit "[lldb] Don't dissasemble large functions by default"
This recommits f665e80c023 which was reverted in 1cbd1b8f692d for breaking
TestFoundationDisassembly.py. The fix is to use --force in the test to avoid
bailing out on large functions.

I have also doubled the large function limit to 8000 bytes (~~ 2000 insns), as
the foundation library contains a lot of large-ish functions. The intent of this
feature is to prevent accidental disassembling of enormous (multi-megabyte)
"functions", not to get in people's way.

The original commit message follows:

If we have a binary without symbol information (and without
LC_FUNCTION_STARTS, if on a mac), then we have to resort to using
heuristics to determine the function boundaries. However, these don't
always work, and so we can easily end up thinking we have functions
which are several megabytes in size. Attempting to (accidentally)
disassemble these can take a very long time spam the terminal with
thousands of lines of disassembly.

This patch works around that problem by adding a sanity check to the
disassemble command. If we are about to disassemble a function which is
larger than a certain threshold, we will refuse to disassemble such a
function unless the user explicitly specifies the number of instructions
to disassemble, uses start/stop addresses for disassembly, or passes the
(new) --force argument.

The threshold is currently fairly aggressive (4000 bytes ~~ 1000
instructions). If needed, we can increase it, or even make it
configurable.

Differential Revision: https://reviews.llvm.org/D79789
2020-05-15 11:57:48 +02:00
shafik
1cbd1b8f69 Revert "[lldb] Don't dissasemble large functions by default"
This reverts commit f665e80c023ec52557f55d7eeaf34471e4c6fa0d.

Reverting because it breaks TestFoundationDisassembly.py
2020-05-14 14:15:51 -07:00
Pavel Labath
f665e80c02 [lldb] Don't dissasemble large functions by default
Summary:
If we have a binary without symbol information (and without
LC_FUNCTION_STARTS, if on a mac), then we have to resort to using
heuristics to determine the function boundaries. However, these don't
always work, and so we can easily end up thinking we have functions
which are several megabytes in size. Attempting to (accidentally)
disassemble these can take a very long time spam the terminal with
thousands of lines of disassembly.

This patch works around that problem by adding a sanity check to the
disassemble command. If we are about to disassemble a function which is
larger than a certain threshold, we will refuse to disassemble such a
function unless the user explicitly specifies the number of instructions
to disassemble, uses start/stop addresses for disassembly, or passes the
(new) --force argument.

The threshold is currently fairly aggressive (4000 bytes ~~ 1000
instructions). If needed, we can increase it, or even make it
configurable.

Differential Revision: https://reviews.llvm.org/D79789
2020-05-14 11:52:54 +02:00
Pavel Labath
1ca1e08e75 [lldb] Break up CommandObjectDisassemble::DoExecute
The function consisted of a complicated set of conditions to compute the
address ranges which are to be disassembled (depending on the mode
selected by command line switches). This patch creates a separate
function for each mode, so that DoExecute is only left with the task of
figuring out how to dump the relevant ranges.

This is NFC-ish, except for one change in the error message, which is
actually an improvement.
2020-03-10 14:03:16 +01:00
Pavel Labath
573e077699 [lldb] Add detailed tests for the "disassemble" command
While we have some tests for this command already, they are very vague.
This is not surprising -- it's hard to make strict assertions about the
assembly if your input is a c++ source file. This means that the tests
can more-or-less only detect when the command breaks completely, and not
when there is a subtle change in meaning due to e.g. a code refactor --
which is something that I am getting ready to do.

This tests in this patch create binaries with well known data (via assembler
and yaml2obj). This means that we are able to make precise assertions
about the text that lldb is supposed to print. As some of the features
of this command are only available with a real process, I use a minidump
core file to create a sufficiently realistic process object.
2020-03-03 16:40:27 +01:00