diff options
Diffstat (limited to 'docs/lldb-gdb-remote.txt')
| -rw-r--r-- | docs/lldb-gdb-remote.txt | 66 |
1 files changed, 47 insertions, 19 deletions
diff --git a/docs/lldb-gdb-remote.txt b/docs/lldb-gdb-remote.txt index 5c4a10c82b49..a882c4abda09 100644 --- a/docs/lldb-gdb-remote.txt +++ b/docs/lldb-gdb-remote.txt @@ -1508,6 +1508,28 @@ for this region. // This packet asks the remote debug stub to send the details about libraries // being added/removed from the process as a performance optimization. // +// There are three ways this packet can be used. All three return a dictionary of +// binary images formatted the same way. +// +// On MacOS X 10.11, iOS 9, tvOS 9, watchOS 2 and earlier, the packet is used like +// jGetLoadedDynamicLibrariesInfos:{"image_count":1,"image_list_address":140734800075128} +// where the image_list_address is an array of {void* load_addr, void* mod_date, void* pathname} +// in the inferior process memory (and image_count is the number of elements in this array). +// lldb is using information from the dyld_all_image_infos structure to make these requests to +// debugserver. This use is not supported on macOS 10.12, iOS 10, tvOS 10, watchOS 3 or newer. +// +// On macOS 10.12, iOS 10, tvOS 10, watchOS 3 and newer, there are two calls. One requests information +// on all shared libraries: +// jGetLoadedDynamicLibrariesInfos:{"fetch_all_solibs":true} +// And the second requests information about a list of shared libraries, given their load addresses: +// jGetLoadedDynamicLibrariesInfos:{"solib_addresses":[8382824135,3258302053,830202858503]} +// +// The second call is both a performance optimization (instead of having lldb read the mach-o header/load commands +// out of memory with generic read packets) but also adds additional information in the form of the +// filename of the shared libraries (which is not available in the mach-o header/load commands.) +// +// An example using the Mac OS X 10.11 style call: +// // LLDB SENDS: jGetLoadedDynamicLibrariesInfos:{"image_count":1,"image_list_address":140734800075128} // STUB REPLIES: ${"images":[{"load_address":4294967296,"mod_date":0,"pathname":"/tmp/a.out","uuid":"02CF262C-ED6F-3965-9E14-63538B465CFF","mach_header":{"magic":4277009103,"cputype":16777223,"cpusubtype":18446744071562067971,"filetype":2},"segments":{"name":"__PAGEZERO","vmaddr":0,"vmsize":4294967296,"fileoff":0,"filesize":0,"maxprot":0},{"name":"__TEXT","vmaddr":4294967296,"vmsize":4096,"fileoff":0,"filesize":4096,"maxprot":7},{"name":"__LINKEDIT","vmaddr":4294971392,"vmsize":4096,"fileoff":4096,"filesize":152,"maxprot":7}}]}#00 // @@ -1562,26 +1584,12 @@ for this region. // quite a bit to provide all the information that the DynamicLoaderMacOSX // would need to work correctly on this platform. // -// On Mac OS X / iOS, when libraries are added or removed, a stub -// function is called which lldb puts a breakpoint on. The arguments -// to the stub function include the number of libraries being added -// or removed and the address where the list of libraries can be -// found. The information at this address is the load address of the -// library, the filename, and the mod date of the library if available. -// DynamicLoaderMacOSX then parses the load commands in the Mach-O header -// at the load address before it can decide what action to take. -// -// The purpose of this packet is to eliminate all of the memory reads needed -// to read the Mach-O header and load commands for these libraries. -// On a typical GUI app, there can be a couple hundred shared libraries -// which results in megabytes of read packets. That same information can -// be returned in a couple hundred kilobytes in JSON format from the remote -// debugserver. -// -// // PRIORITY TO IMPLEMENT -// Low. If this packet is absent, lldb will read the Mach-O headers/load -// commands out of memory. +// On Mac OS X 10.11, iOS 9, tvOS 9, watchOS 2 and older: Low. If this packet is absent, +// lldb will read the Mach-O headers/load commands out of memory. +// On macOS 10.12, iOS 10, tvOS 10, watchOS 3 and newer: High. If this packet is absent, +// lldb will not know anything about shared libraries in the inferior, or where the main +// executable loaded. //---------------------------------------------------------------------- //---------------------------------------------------------------------- @@ -1649,6 +1657,26 @@ the previous FP and PC), and follow the backchain. Most backtraces on MacOSX and iOS now don't require us to read any memory! //---------------------------------------------------------------------- +// "jGetSharedCacheInfo" +// +// BRIEF +// This packet asks the remote debug stub to send the details about the inferior's +// shared cache. The shared cache is a collection of common libraries/frameworks that +// are mapped into every process at the same address on Darwin systems, and can be +// identified by a load address and UUID. +// +// +// LLDB SENDS: jGetSharedCacheInfo:{} +// STUB REPLIES: ${"shared_cache_base_address":140735683125248,"shared_cache_uuid":"DDB8D70C-C9A2-3561-B2C8-BE48A4F33F96","no_shared_cache":false,"shared_cache_private_cache":false]}#00 +// +// PRIORITY TO IMPLEMENT +// Low. When both lldb and the inferior process are running on the same computer, and lldb +// and the inferior process have the same shared cache, lldb may (as an optimization) read +// the shared cache out of its own memory instead of using gdb-remote read packets to read +// them from the inferior process. +//---------------------------------------------------------------------- + +//---------------------------------------------------------------------- // "qQueryGDBServer" // // BRIEF |