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author | Jason Molenda <jmolenda@apple.com> | 2024-02-05 18:45:01 -0800 |
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committer | GitHub <noreply@github.com> | 2024-02-05 18:45:01 -0800 |
commit | 5953532615595918d006ace2ad83fe33d1cd3915 (patch) | |
tree | 0059810a9a588b16f85e8f10a1153463c9b521c5 /lldb/docs | |
parent | 8f80df0f52c4294d23d0510b01be6d6491714058 (diff) | |
download | llvm-5953532615595918d006ace2ad83fe33d1cd3915.zip llvm-5953532615595918d006ace2ad83fe33d1cd3915.tar.gz llvm-5953532615595918d006ace2ad83fe33d1cd3915.tar.bz2 |
[lldb] Add QSupported key to report watchpoint types supported (#80376)
debugserver on arm64 devices can manage both Byte Address Select
watchpoints (1-8 bytes) and MASK watchpoints (8 bytes-2 gigabytes). This
adds a SupportedWatchpointTypes key to the QSupported response from
debugserver with a list of these, so lldb can take full advantage of
them when creating larger regions with a single hardware watchpoint.
Also add documentation for this, and two other lldb extensions, to the
lldb-gdb-remote.txt documentation.
Re-enable TestLargeWatchpoint.py on Darwin systems when testing with the
in-tree built debugserver. I can remove the "in-tree built debugserver"
in the future when this new key is handled by an Xcode debugserver.
Diffstat (limited to 'lldb/docs')
-rw-r--r-- | lldb/docs/lldb-gdb-remote.txt | 56 |
1 files changed, 47 insertions, 9 deletions
diff --git a/lldb/docs/lldb-gdb-remote.txt b/lldb/docs/lldb-gdb-remote.txt index 58269e4..76ac3f2 100644 --- a/lldb/docs/lldb-gdb-remote.txt +++ b/lldb/docs/lldb-gdb-remote.txt @@ -38,7 +38,45 @@ read packet: + read packet: $OK#9a send packet: + +//---------------------------------------------------------------------- +// "QSupported" +// +// BRIEF +// Query the GDB remote server for features it supports +// +// PRIORITY TO IMPLEMENT +// Optional. +//---------------------------------------------------------------------- + +QSupported is a standard GDB Remote Serial Protocol packet, but +there are several additions to the response that lldb can parse. +They are not all listed here. + +An example exchange: + +send packet: qSupported:xmlRegisters=i386,arm,mips,arc;multiprocess+;fork-events+;vfork-events+ + +read packet: qXfer:features:read+;PacketSize=20000;qEcho+;native-signals+;SupportedCompressions=lzfse,zlib-deflate,lz4,lzma;SupportedWatchpointTypes=aarch64-mask,aarch64-bas; + +In the example above, three lldb extensions are shown: + PacketSize=20000 + The base 16 maximum packet size that the stub can handle. + SupportedCompressions=<item,item,...> + A list of compression types that the stub can use to compress packets + when the QEnableCompression packet is used to request one of them. + SupportedWatchpointTypes=<item,item,...> + A list of watchpoint types that this stub can manage. + Currently defined names are: + x86_64 64-bit x86-64 watchpoints + (1, 2, 4, 8 byte watchpoints aligned to those amounts) + aarch64-bas AArch64 Byte Address Select watchpoints + (any number of contiguous bytes within a doubleword) + aarch64-mask AArch64 MASK watchpoints + (any power-of-2 region of memory from 8 to 2GB, aligned) + If nothing is specified, lldb will default to sending power-of-2 + watchpoints, up to a pointer size, `sizeof(void*)`, a reasonable + baseline assumption. //---------------------------------------------------------------------- // "A" - launch args packet @@ -594,7 +632,7 @@ read packet: <binary data>/E<error code>;AAAAAAAAA With LLDB, for register information, remote GDB servers can add support for the "qRegisterInfoN" packet where "N" is a zero based -base16 register number that must start at zero and increase by one +base 16 register number that must start at zero and increase by one for each register that is supported. The response is done in typical GDB remote fashion where a series of "KEY:VALUE;" pairs are returned. An example for the x86_64 registers is included below: @@ -1053,7 +1091,7 @@ Suggested key names: // 64-bit slices so it may be impossible to know until you're attached to a real // process to know what you're working with. // -// All numeric fields return base-16 numbers without any "0x" prefix. +// All numeric fields return base 16 numbers without any "0x" prefix. //---------------------------------------------------------------------- An i386 process: @@ -1085,7 +1123,7 @@ main-binary-uuid: is the UUID of a firmware type binary that the gdb stub knows main-binary-address: is the load address of the firmware type binary main-binary-slide: is the slide of the firmware type binary, if address isn't known -binary-addresses: A comma-separated list of binary load addresses base16. +binary-addresses: A comma-separated list of binary load addresses base 16. lldb will parse the binaries in memory to get UUIDs, then try to find the binaries & debug info by UUID. Intended for use with a small number of firmware type binaries where the @@ -1302,7 +1340,7 @@ tuples to return are: dirty-pages:[<hexaddr>][,<hexaddr]; // A list of memory pages within this // region that are "dirty" -- they have been modified. - // Page addresses are in base16. The size of a page can + // Page addresses are in base 16. The size of a page can // be found from the qHostInfo's page-size key-value. // // If the stub supports identifying dirty pages within a @@ -1585,7 +1623,7 @@ for this region. // describe why something stopped. // // For "reason:watchpoint", "description" is an ascii-hex -// encoded string with between one and three base10 numbers, +// encoded string with between one and three base 10 numbers, // space separated. The three numbers are // 1. watchpoint address. This address should always be within // a memory region lldb has a watchpoint on. @@ -1911,7 +1949,7 @@ for this region. // // jThreadExtendedInfo:{"thread":612910} // -// Because this is a JSON string, the thread number is provided in base10. +// Because this is a JSON string, the thread number is provided in base 10. // Additional key-value pairs may be provided by lldb to the gdb remote // stub. For instance, on some versions of macOS, lldb can read offset // information out of the system libraries. Using those offsets, debugserver @@ -1980,13 +2018,13 @@ for this region. // // $N<uncompressed payload>#00 // -// $C<size of uncompressed payload in base10>:<compressed payload>#00 +// $C<size of uncompressed payload in base 10>:<compressed payload>#00 // // Where "#00" is the actual checksum value if noack mode is not enabled. The checksum // value is for the "N<uncompressed payload>" or -// "C<size of uncompressed payload in base10>:<compressed payload>" bytes in the packet. +// "C<size of uncompressed payload in base 10>:<compressed payload>" bytes in the packet. // -// The size of the uncompressed payload in base10 is provided because it will simplify +// The size of the uncompressed payload in base 10 is provided because it will simplify // decompression if the final buffer size needed is known ahead of time. // // Compression on low-latency connections is unlikely to be an improvement. Particularly |