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
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
Make it possible to use a relative path in command script import to the
location of the file being sourced. This allows the user to put Python
scripts next to LLDB command files and importing them without having to
specify an absolute path.
To enable this behavior pass `-c` to `command script import`. The
argument can only be used when sourcing the command from a file.
rdar://68310384
Differential revision: https://reviews.llvm.org/D89334
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.
Pedro Tammela