就像任何可爱的开发人员工具一样，LLDB船舶具有健康的文档。知道如何浏览此文档 - 包括一些更模糊的命令标志 - 对于掌握LLDB至关重要。
Terminal window and type
lldb. The LLDB prompt will appear. From there, simply type the
This will dump out all available commands, including the custom commands loaded from your
~/.lldbinit — but more on that later.
breakpoint command for instance. Run the documentation for
breakpoint by typing the following:
(lldb) help breakpoint
Commands for operating on breakpoints (see 'help b' for shorthand.) Syntax: breakpoint The following subcommands are supported: clear -- Delete or disable breakpoints matching the specified source file and line. command -- Commands for adding, removing and listing LLDB commands executed when a breakpoint is hit. delete -- Delete the specified breakpoint(s). If no breakpoints are specified, delete them all. disable -- Disable the specified breakpoint(s) without deleting them. If none are specified, disable all breakpoints. enable -- Enable the specified disabled breakpoint(s). If no breakpoints are specified, enable all of them. list -- List some or all breakpoints at configurable levels of detail. modify -- Modify the options on a breakpoint or set of breakpoints in the executable. If no breakpoint is specified, acts on the last created breakpoint. With the exception of -e, -d and -i, passing an empty argument clears the modification. name -- Commands to manage name tags for breakpoints read -- Read and set the breakpoints previously saved to a file with "breakpoint write". set -- Sets a breakpoint or set of breakpoints in the executable. write -- Write the breakpoints listed to a file that can be read in with "breakpoint read". If given no arguments, writes all breakpoints. For more help on any particular subcommand, type 'help <command> <subcommand>'.
From there, you can see several supported subcommands. Look up the documentation for
breakpoint name by typing the following:
(lldb) help breakpoint name
Commands to manage name tags for breakpoints Syntax: breakpoint name The following subcommands are supported: add -- Add a name to the breakpoints provided. configure -- Configure the options for the breakpoint name provided. If you provide a breakpoint ID, the options will be copied from the breakpoint, otherwise only the options specified will be set on the name. delete -- Delete a name from the breakpoints provided. list -- List either the names for a breakpoint or info about a given name. With no arguments, lists all names For more help on any particular subcommand, type 'help <command> <subcommand>'.
If you don’t understand
breakpoint name at the moment, don’t worry — you’ll become familiar with breakpoints and all of the subsequent commands soon. For now, the
help command is the most important command you can remember.
Sometimes you don’t know the name of the command you’re searching for, but you know a certain word or phrase that might point you in the right direction. The
apropos command can do this for you; it’s a bit like using a search engine to find something on the web.
(lldb) apropos swift
The following commands may relate to 'swift': swift -- A set of commands for operating on the Swift Language Runtime. demangle -- Demangle a Swift mangled name refcount -- Inspect the reference count data for a Swift object The following settings variables may relate to 'swift': target.swift-framework-search-paths -- List of directories to be searched when locating frameworks for Swift. target.swift-module-search-paths -- List of directories to be searched when locating modules for Swift. target.use-all-compiler-flags -- Try to use compiler flags for all modules when setting up the Swift expression parser, not just the main executable. target.experimental.swift-create-module-contexts-in-parallel -- Create the per-module Swift AST contexts in parallel.
(lldb) apropos "reference count" The following commands may relate to 'reference count': refcount -- Inspect the reference count data for a Swift object
It’s easy to forget the onslaught of LLDB commands that will soon come, but try to commit these two commands,
apropos, to heart. They’re the foundation for querying information on commands and you’ll be using them all the time as you master debugging.