When executing a script command in HandleCommand(s) we currently print
its output twice
You can see this issue in action when adding a breakpoint command:
(lldb) b main
Breakpoint 1: where = main.out`main + 13 at main.cpp:2:3, address = 0x0000000100003fad
(lldb) break command add 1 -o "script print(\"Hey!\")"
(lldb) r
Process 76041 launched: '/tmp/main.out' (x86_64)
Hey!
(lldb) script print("Hey!")
Hey!
Process 76041 stopped
The issue is caused by HandleCommands using a temporary
CommandReturnObject and one of the commands (`script` in this case)
setting an immediate output stream. This causes the result to be printed
twice: once directly to the immediate output stream and once when
printing the result of HandleCommands.
This patch fixes the issue by introducing a new option to suppress
immediate output for temporary CommandReturnObjects.
Differential revision: https://reviews.llvm.org/D103349
Adds support for running a Lua function when a breakpoint is hit.
Example:
breakpoint command add -s lua -F abc
The above runs the Lua function 'abc' passing 2 arguments. 'frame', 'bp_loc' and 'extra_args'.
A third parameter 'extra_args' is only present when there is structured data
declared in the command line.
Example:
breakpoint command add -s lua -F abc -k foo -v bar
Differential Revision: https://reviews.llvm.org/D93649
1 - Partial Statements
The interpreter loop runs every line it receives, so partial
Lua statements are not being handled properly. This is a problem for
multiline breakpoint scripts since the interpreter loop, for this
particular case, is just an abstraction to a partially parsed function
body declaration.
This patch addresses this issue and as a side effect improves the
general Lua interpreter loop as well. It's now possible to write partial
statements in the 'script' command.
Example:
(lldb) script
>>> do
..> local a = 123
..> print(a)
..> end
123
The technique implemented is the same as the one employed by Lua's own REPL implementation.
Partial statements always errors out with the '<eof>' tag in the error
message.
2 - CheckSyntax in Lua.h
In order to support (1), we need an API for just checking the syntax of string buffers.
3 - Multiline scripted breakpoints
Finally, with all the base features implemented this feature is
straightforward. The interpreter loop behaves exactly the same, the
difference is that it will aggregate all Lua statements into the body of
the breakpoint function. An explicit 'quit' statement is needed to exit the
interpreter loop.
Example:
(lldb) breakpoint command add -s lua
Enter your Lua command(s). Type 'quit' to end.
The commands are compiled as the body of the following Lua function
function (frame, bp_loc, ...) end
..> print(456)
..> a = 123
..> quit
Differential Revision: https://reviews.llvm.org/D93481
LLDB is ignoring compilation errors for one-line breakpoint scripts.
This patch fixes the issues and now the error message of the
ScriptInterpreter is shown to the user.
I had to remove a new-line character for the Lua interpreter since it
was duplicated.
Differential Revision: https://reviews.llvm.org/D92729
These callbacks are set using the following:
breakpoint command add -s lua -o "print('hello world!')"
The user supplied script is executed as:
function (frame, bp_loc, ...)
<body>
end
So the local variables 'frame', 'bp_loc' and vararg are all accessible.
Any global variables declared will persist in the Lua interpreter.
A user should never hold 'frame' and 'bp_loc' in a global variable as
these userdatas are context dependent.
Differential Revision: https://reviews.llvm.org/D91508
This patch changes the implementation of Lua's `print()` function to
respect `io.stdout`.
The original implementation uses `lua_writestring()` internally, which is
hardcoded to `stdout`.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D90787
Make it possible to run the script command with a different language
than currently selected.
$ ./bin/lldb -l python
(lldb) script -l lua
>>> io.stdout:write("Hello, World!\n")
Hello, World!
When passing the language option and a raw command, you need to separate
the flag from the script code with --.
$ ./bin/lldb -l python
(lldb) script -l lua -- io.stdout:write("Hello, World!\n")
Hello, World!
Differential revision: https://reviews.llvm.org/D86996
Add support for changing the stdout and stderr file in Lua's I/O library
and hook it up with the debugger's output and error file respectively
for the interactive Lua interpreter.
https://reviews.llvm.org/D82273
Add a way to quit the interactive script interpreter from a shell tests.
Currently, the only way (that I know) to exit the interactive Lua
interpreter is to send a EOF with CTRL-D. I noticed that the embedded
Python script interpreter accepts quit (while the regular python
interpreter doesn't). I've added a special case to the Lua interpreter
to do the same.
Differential revision: https://reviews.llvm.org/D82272
The reproducers currently only shadow the command interpreter. It would
be possible to make it work for the Lua interpreter which uses the
IOHandlerEditline under the hood, but the Python one runs a REPL in
Python itself so there's no (straightforward) way to shadow that.
Given that we already capture any API calls, this isn't super high on my
list of priorities.
The Python script interpreter makes the current debugger, target,
process, thread and frame available to interactive scripting sessions
through convenience variables. This patch does the same for Lua.
Differential revision: https://reviews.llvm.org/D71801
Don't create a new lua state on every operation. Share a single state
across the lifetime of the script interpreter. Add simple locking to
prevent two threads from modifying the state concurrently.
This implements a very elementary Lua script interpreter. It supports
running a single command as well as running interactively. It uses
editline if available. It's still missing a bunch of stuff though. Some
things that I intentionally ingored for now are that I/O isn't properly
hooked up (so every print goes to stdout) and the non-editline support
which is not handling a bunch of corner cases. The latter is a matter of
reusing existing code in the Python interpreter.
Discussion on the mailing list:
http://lists.llvm.org/pipermail/lldb-dev/2019-December/015812.html
Differential revision: https://reviews.llvm.org/D71234
Siger Yang